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authordon bright <hugh.m.bright@gmail.com>2013-01-24 03:02:31 (GMT)
committerdon bright <hugh.m.bright@gmail.com>2013-01-24 03:02:31 (GMT)
commit1e7636e364535c78e4eebd36666bac5d352c3608 (patch)
tree5479c9229973795a771f912f3c3414f2075f2875 /src
parent1bec7aad09631d3f86874ead2c26335bc897fde5 (diff)
add files removed from test path
Diffstat (limited to 'src')
-rw-r--r--src/OffscreenContext.h13
-rw-r--r--src/OffscreenContext.mm146
-rw-r--r--src/OffscreenContextGLX.cc328
-rw-r--r--src/OffscreenContextWGL.cc247
-rw-r--r--src/OffscreenView.cc170
-rw-r--r--src/OffscreenView.h45
-rw-r--r--src/fbo.cc237
-rw-r--r--src/fbo.h25
-rw-r--r--src/imageutils-lodepng.cc24
-rw-r--r--src/imageutils-macosx.cc64
-rw-r--r--src/imageutils.cc16
-rw-r--r--src/imageutils.h9
-rw-r--r--src/lodepng.cpp5797
-rw-r--r--src/lodepng.h1899
14 files changed, 9020 insertions, 0 deletions
diff --git a/src/OffscreenContext.h b/src/OffscreenContext.h
new file mode 100644
index 0000000..6eebcba
--- /dev/null
+++ b/src/OffscreenContext.h
@@ -0,0 +1,13 @@
+#ifndef OFFSCREENCONTEXT_H_
+#define OFFSCREENCONTEXT_H_
+
+#include <iostream> // for error output
+#include <string>
+
+struct OffscreenContext *create_offscreen_context(int w, int h);
+void bind_offscreen_context(OffscreenContext *ctx);
+bool teardown_offscreen_context(OffscreenContext *ctx);
+bool save_framebuffer(OffscreenContext *ctx, const char *filename);
+std::string offscreen_context_getinfo(OffscreenContext *ctx);
+
+#endif
diff --git a/src/OffscreenContext.mm b/src/OffscreenContext.mm
new file mode 100644
index 0000000..a0995fa
--- /dev/null
+++ b/src/OffscreenContext.mm
@@ -0,0 +1,146 @@
+#include "OffscreenContext.h"
+#include "imageutils.h"
+#include "fbo.h"
+#include <iostream>
+#include <sstream>
+
+#import <AppKit/AppKit.h> // for NSOpenGL...
+#include <CoreServices/CoreServices.h>
+#include <sys/utsname.h>
+
+#define REPORTGLERROR(task) { GLenum tGLErr = glGetError(); if (tGLErr != GL_NO_ERROR) { std::cout << "OpenGL error " << tGLErr << " while " << task << "\n"; } }
+
+struct OffscreenContext
+{
+ NSOpenGLContext *openGLContext;
+ NSAutoreleasePool *pool;
+ int width;
+ int height;
+ fbo_t *fbo;
+};
+
+std::string offscreen_context_getinfo(OffscreenContext *ctx)
+{
+ std::stringstream out;
+
+ struct utsname name;
+ uname(&name);
+
+ SInt32 majorVersion,minorVersion,bugFixVersion;
+
+ Gestalt(gestaltSystemVersionMajor, &majorVersion);
+ Gestalt(gestaltSystemVersionMinor, &minorVersion);
+ Gestalt(gestaltSystemVersionBugFix, &bugFixVersion);
+
+ const char *arch = "unknown";
+ if (sizeof(int*) == 4) arch = "32-bit";
+ else if (sizeof(int*) == 8) arch = "64-bit";
+
+ out << "GL context creator: Cocoa / CGL\n"
+ << "PNG generator: Core Foundation\n"
+ << "OS info: Mac OS X " << majorVersion << "." << minorVersion << "." << bugFixVersion << " (" << name.machine << " kernel)\n"
+ << "Machine: " << arch << "\n";
+ return out.str();
+}
+
+OffscreenContext *create_offscreen_context(int w, int h)
+{
+ OffscreenContext *ctx = new OffscreenContext;
+ ctx->width = w;
+ ctx->height = h;
+
+ ctx->pool = [NSAutoreleasePool new];
+
+ // Create an OpenGL context just so that OpenGL calls will work.
+ // Will not be used for actual rendering.
+
+ NSOpenGLPixelFormatAttribute attributes[] = {
+ NSOpenGLPFAPixelBuffer,
+ NSOpenGLPFANoRecovery,
+ NSOpenGLPFADepthSize, 24,
+ NSOpenGLPFAStencilSize, 8,
+// Took out the acceleration requirement to be able to run the tests
+// in a non-accelerated VM.
+// NSOpenGLPFAAccelerated,
+ (NSOpenGLPixelFormatAttribute) 0
+ };
+ NSOpenGLPixelFormat *pixFormat = [[[NSOpenGLPixelFormat alloc] initWithAttributes:attributes] autorelease];
+
+ // Create and make current the OpenGL context to render with (with color and depth buffers)
+ ctx->openGLContext = [[NSOpenGLContext alloc] initWithFormat:pixFormat shareContext:nil];
+ if (!ctx->openGLContext) {
+ std::cerr << "Unable to create NSOpenGLContext\n";
+ return NULL;
+ }
+
+ [ctx->openGLContext makeCurrentContext];
+
+ // glewInit must come after Context creation and before FBO calls.
+ GLenum err = glewInit();
+ if (GLEW_OK != err) {
+ std::cerr << "Unable to init GLEW: " << glewGetErrorString(err) << std::endl;
+ return NULL;
+ }
+ glew_dump();
+
+ ctx->fbo = fbo_new();
+ if (!fbo_init(ctx->fbo, w, h)) {
+ return NULL;
+ }
+
+ return ctx;
+}
+
+bool teardown_offscreen_context(OffscreenContext *ctx)
+{
+ fbo_unbind(ctx->fbo);
+ fbo_delete(ctx->fbo);
+
+ /*
+ * Cleanup
+ */
+ [ctx->openGLContext clearDrawable];
+ [ctx->openGLContext release];
+
+ [ctx->pool release];
+ return true;
+}
+
+/*!
+ Capture framebuffer from OpenGL and write it to the given filename as PNG.
+*/
+bool save_framebuffer(OffscreenContext *ctx, const char *filename)
+{
+ if (!ctx || !filename) return false;
+ // Read pixels from OpenGL
+ int samplesPerPixel = 4; // R, G, B and A
+ int rowBytes = samplesPerPixel * ctx->width;
+ unsigned char *bufferData = (unsigned char *)malloc(rowBytes * ctx->height);
+ if (!bufferData) {
+ std::cerr << "Unable to allocate buffer for image extraction.";
+ return 1;
+ }
+ glReadPixels(0, 0, ctx->width, ctx->height, GL_RGBA, GL_UNSIGNED_BYTE,
+ bufferData);
+ REPORTGLERROR("reading pixels from framebuffer");
+
+ // Flip it vertically - images read from OpenGL buffers are upside-down
+ unsigned char *flippedBuffer = (unsigned char *)malloc(rowBytes * ctx->height);
+ if (!flippedBuffer) {
+ std::cout << "Unable to allocate flipped buffer for corrected image.";
+ return 1;
+ }
+ flip_image(bufferData, flippedBuffer, samplesPerPixel, ctx->width, ctx->height);
+
+ bool writeok = write_png(filename, flippedBuffer, ctx->width, ctx->height);
+
+ free(flippedBuffer);
+ free(bufferData);
+
+ return writeok;
+}
+
+void bind_offscreen_context(OffscreenContext *ctx)
+{
+ fbo_bind(ctx->fbo);
+}
diff --git a/src/OffscreenContextGLX.cc b/src/OffscreenContextGLX.cc
new file mode 100644
index 0000000..e607593
--- /dev/null
+++ b/src/OffscreenContextGLX.cc
@@ -0,0 +1,328 @@
+/*
+
+Create an OpenGL context without creating an OpenGL Window. for Linux.
+
+See Also
+
+ glxgears.c by Brian Paul from mesa-demos (mesa3d.org)
+ http://cgit.freedesktop.org/mesa/demos/tree/src/xdemos?id=mesa-demos-8.0.1
+ http://www.opengl.org/sdk/docs/man/xhtml/glXIntro.xml
+ http://www.mesa3d.org/brianp/sig97/offscrn.htm
+ http://glprogramming.com/blue/ch07.html
+ OffscreenContext.mm (Mac OSX version)
+
+*/
+
+/*
+ * Some portions of the code below are:
+ * Copyright (C) 1999-2001 Brian Paul All Rights Reserved.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included
+ * in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
+ * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+ * BRIAN PAUL BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
+ * AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+ * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+
+#include "OffscreenContext.h"
+#include "printutils.h"
+#include "imageutils.h"
+#include "system-gl.h"
+#include "fbo.h"
+
+#include <GL/gl.h>
+#include <GL/glx.h>
+
+#include <assert.h>
+#include <sstream>
+
+#include <sys/utsname.h> // for uname
+
+using namespace std;
+
+struct OffscreenContext
+{
+ GLXContext openGLContext;
+ Display *xdisplay;
+ Window xwindow;
+ int width;
+ int height;
+ fbo_t *fbo;
+};
+
+void offscreen_context_init(OffscreenContext &ctx, int width, int height)
+{
+ ctx.width = width;
+ ctx.height = height;
+ ctx.openGLContext = NULL;
+ ctx.xdisplay = NULL;
+ ctx.xwindow = (Window)NULL;
+ ctx.fbo = NULL;
+}
+
+string get_os_info()
+{
+ struct utsname u;
+ stringstream out;
+
+ if (uname(&u) < 0)
+ out << "OS info: unknown, uname() error\n";
+ else {
+ out << "OS info: "
+ << u.sysname << " "
+ << u.release << " "
+ << u.version << "\n";
+ out << "Machine: " << u.machine;
+ }
+ return out.str();
+}
+
+string offscreen_context_getinfo(OffscreenContext *ctx)
+{
+ assert(ctx);
+
+ if (!ctx->xdisplay)
+ return string("No GL Context initialized. No information to report\n");
+
+ int major, minor;
+ glXQueryVersion(ctx->xdisplay, &major, &minor);
+
+ stringstream out;
+ out << "GL context creator: GLX\n"
+ << "PNG generator: lodepng\n"
+ << "GLX version: " << major << "." << minor << "\n"
+ << get_os_info();
+
+ return out.str();
+}
+
+static XErrorHandler original_xlib_handler = (XErrorHandler) NULL;
+static bool XCreateWindow_failed = false;
+static int XCreateWindow_error(Display *dpy, XErrorEvent *event)
+{
+ cerr << "XCreateWindow failed: XID: " << event->resourceid
+ << " request: " << (int)event->request_code
+ << " minor: " << (int)event->minor_code << "\n";
+ char description[1024];
+ XGetErrorText( dpy, event->error_code, description, 1023 );
+ cerr << " error message: " << description << "\n";
+ XCreateWindow_failed = true;
+ return 0;
+}
+
+bool create_glx_dummy_window(OffscreenContext &ctx)
+{
+ /*
+ create a dummy X window without showing it. (without 'mapping' it)
+ and save information to the ctx.
+
+ This purposely does not use glxCreateWindow, to avoid crashes,
+ "failed to create drawable" errors, and Mesa "WARNING: Application calling
+ GLX 1.3 function when GLX 1.3 is not supported! This is an application bug!"
+
+ This function will alter ctx.openGLContext and ctx.xwindow if successfull
+ */
+
+ int attributes[] = {
+ GLX_DRAWABLE_TYPE, GLX_WINDOW_BIT | GLX_PIXMAP_BIT | GLX_PBUFFER_BIT, //support all 3, for OpenCSG
+ GLX_RENDER_TYPE, GLX_RGBA_BIT,
+ GLX_RED_SIZE, 8,
+ GLX_GREEN_SIZE, 8,
+ GLX_BLUE_SIZE, 8,
+ GLX_ALPHA_SIZE, 8,
+ GLX_DEPTH_SIZE, 24, // depth-stencil for OpenCSG
+ GLX_STENCIL_SIZE, 8,
+ GLX_DOUBLEBUFFER, True,
+ None
+ };
+
+ Display *dpy = ctx.xdisplay;
+
+ int num_returned = 0;
+ GLXFBConfig *fbconfigs = glXChooseFBConfig( dpy, DefaultScreen(dpy), attributes, &num_returned );
+ if ( fbconfigs == NULL ) {
+ cerr << "glXChooseFBConfig failed\n";
+ return false;
+ }
+
+ XVisualInfo *visinfo = glXGetVisualFromFBConfig( dpy, fbconfigs[0] );
+ if ( visinfo == NULL ) {
+ cerr << "glXGetVisualFromFBConfig failed\n";
+ XFree( fbconfigs );
+ return false;
+ }
+
+ // can't depend on xWin==NULL at failure. use a custom Xlib error handler instead.
+ original_xlib_handler = XSetErrorHandler( XCreateWindow_error );
+
+ Window root = DefaultRootWindow( dpy );
+ XSetWindowAttributes xwin_attr;
+ int width = ctx.width;
+ int height = ctx.height;
+ xwin_attr.background_pixmap = None;
+ xwin_attr.background_pixel = 0;
+ xwin_attr.border_pixel = 0;
+ xwin_attr.colormap = XCreateColormap( dpy, root, visinfo->visual, AllocNone);
+ xwin_attr.event_mask = StructureNotifyMask | ExposureMask | KeyPressMask;
+ unsigned long int mask = CWBackPixel | CWBorderPixel | CWColormap | CWEventMask;
+
+ Window xWin = XCreateWindow( dpy, root, 0, 0, width, height,
+ 0, visinfo->depth, InputOutput,
+ visinfo->visual, mask, &xwin_attr );
+
+ // Window xWin = XCreateSimpleWindow( dpy, DefaultRootWindow(dpy), 0,0,42,42, 0,0,0 );
+
+ XSync( dpy, false );
+ if ( XCreateWindow_failed ) {
+ XFree( visinfo );
+ XFree( fbconfigs );
+ return false;
+ }
+ XSetErrorHandler( original_xlib_handler );
+
+ // Most programs would call XMapWindow here. But we don't, to keep the window hidden
+ // XMapWindow( dpy, xWin );
+
+ GLXContext context = glXCreateNewContext( dpy, fbconfigs[0], GLX_RGBA_TYPE, NULL, True );
+ if ( context == NULL ) {
+ cerr << "glXCreateNewContext failed\n";
+ XDestroyWindow( dpy, xWin );
+ XFree( visinfo );
+ XFree( fbconfigs );
+ return false;
+ }
+
+ //GLXWindow glxWin = glXCreateWindow( dpy, fbconfigs[0], xWin, NULL );
+
+ if (!glXMakeContextCurrent( dpy, xWin, xWin, context )) {
+ //if (!glXMakeContextCurrent( dpy, glxWin, glxWin, context )) {
+ cerr << "glXMakeContextCurrent failed\n";
+ glXDestroyContext( dpy, context );
+ XDestroyWindow( dpy, xWin );
+ XFree( visinfo );
+ XFree( fbconfigs );
+ return false;
+ }
+
+ ctx.openGLContext = context;
+ ctx.xwindow = xWin;
+
+ XFree( visinfo );
+ XFree( fbconfigs );
+
+ return true;
+}
+
+
+Bool create_glx_dummy_context(OffscreenContext &ctx)
+{
+ // This will alter ctx.openGLContext and ctx.xdisplay and ctx.xwindow if successfull
+ int major;
+ int minor;
+ Bool result = False;
+
+ ctx.xdisplay = XOpenDisplay( NULL );
+ if ( ctx.xdisplay == NULL ) {
+ cerr << "Unable to open a connection to the X server\n";
+ return False;
+ }
+
+ // glxQueryVersion is not always reliable. Use it, but then
+ // also check to see if GLX 1.3 functions exist
+
+ glXQueryVersion(ctx.xdisplay, &major, &minor);
+
+ if ( major==1 && minor<=2 && glXGetVisualFromFBConfig==NULL ) {
+ cerr << "Error: GLX version 1.3 functions missing. "
+ << "Your GLX version: " << major << "." << minor << endl;
+ } else {
+ result = create_glx_dummy_window(ctx);
+ }
+
+ if (!result) XCloseDisplay( ctx.xdisplay );
+ return result;
+}
+
+OffscreenContext *create_offscreen_context(int w, int h)
+{
+ OffscreenContext *ctx = new OffscreenContext;
+ offscreen_context_init( *ctx, w, h );
+
+ // before an FBO can be setup, a GLX context must be created
+ // this call alters ctx->xDisplay and ctx->openGLContext
+ // and ctx->xwindow if successfull
+ if (!create_glx_dummy_context( *ctx )) {
+ return NULL;
+ }
+
+ // glewInit must come after Context creation and before FBO calls.
+ GLenum err = glewInit();
+ if (GLEW_OK != err) {
+ cerr << "Unable to init GLEW: " << glewGetErrorString(err) << endl;
+ return NULL;
+ }
+
+ ctx->fbo = fbo_new();
+ if (!fbo_init(ctx->fbo, w, h)) {
+ cerr << "GL Framebuffer Object init failed; dumping GLEW info" << endl;
+ return NULL;
+ }
+
+ return ctx;
+}
+
+bool teardown_offscreen_context(OffscreenContext *ctx)
+{
+ if (ctx) {
+ fbo_unbind(ctx->fbo);
+ fbo_delete(ctx->fbo);
+ XDestroyWindow( ctx->xdisplay, ctx->xwindow );
+ glXDestroyContext( ctx->xdisplay, ctx->openGLContext );
+ XCloseDisplay( ctx->xdisplay );
+ return true;
+ }
+ return false;
+}
+
+/*!
+ Capture framebuffer from OpenGL and write it to the given filename as PNG.
+*/
+bool save_framebuffer(OffscreenContext *ctx, const char *filename)
+{
+ glXSwapBuffers(ctx->xdisplay, ctx->xwindow);
+ if (!ctx || !filename) return false;
+ int samplesPerPixel = 4; // R, G, B and A
+ GLubyte pixels[ctx->width * ctx->height * samplesPerPixel];
+ glReadPixels(0, 0, ctx->width, ctx->height, GL_RGBA, GL_UNSIGNED_BYTE, pixels);
+
+ // Flip it vertically - images read from OpenGL buffers are upside-down
+ int rowBytes = samplesPerPixel * ctx->width;
+ unsigned char *flippedBuffer = (unsigned char *)malloc(rowBytes * ctx->height);
+ if (!flippedBuffer) {
+ cerr << "Unable to allocate flipped buffer for corrected image.";
+ return 1;
+ }
+ flip_image(pixels, flippedBuffer, samplesPerPixel, ctx->width, ctx->height);
+
+ bool writeok = write_png(filename, flippedBuffer, ctx->width, ctx->height);
+
+ free(flippedBuffer);
+
+ return writeok;
+}
+
+void bind_offscreen_context(OffscreenContext *ctx)
+{
+ if (ctx) fbo_bind(ctx->fbo);
+}
diff --git a/src/OffscreenContextWGL.cc b/src/OffscreenContextWGL.cc
new file mode 100644
index 0000000..75a7ed2
--- /dev/null
+++ b/src/OffscreenContextWGL.cc
@@ -0,0 +1,247 @@
+/*
+
+Create an OpenGL context without creating an OpenGL Window. for Windows.
+
+For more info:
+
+ http://www.nullterminator.net/opengl32.html by Blaine Hodge
+ http://msdn.microsoft.com/en-us/library/ee418815(v=vs.85).aspx
+ http://www.cprogramming.com/tutorial/wgl_wiggle_functions.html by RoD
+ ( which includes robot.cc by Steven Billington )
+ http://blogs.msdn.com/b/oldnewthing/archive/2006/12/04/1205831.aspx by Tom
+*/
+
+#include <windows.h>
+#include <vector>
+
+#include "OffscreenContext.h"
+#include "printutils.h"
+#include "imageutils.h"
+#include "system-gl.h"
+#include "fbo.h"
+
+#include <GL/gl.h> // must be included after glew.h
+
+#include <map>
+#include <string>
+#include <sstream>
+
+using namespace std;
+
+struct OffscreenContext
+{
+ HWND window;
+ HDC dev_context;
+ HGLRC openGLContext;
+ int width;
+ int height;
+ fbo_t *fbo;
+};
+
+void offscreen_context_init(OffscreenContext &ctx, int width, int height)
+{
+ ctx.window = (HWND)NULL;
+ ctx.dev_context = (HDC)NULL;
+ ctx.openGLContext = (HGLRC)NULL;
+ ctx.width = width;
+ ctx.height = height;
+ ctx.fbo = NULL;
+}
+
+string get_os_info()
+{
+ OSVERSIONINFO osvi;
+
+ ZeroMemory(&osvi, sizeof(OSVERSIONINFO));
+ osvi.dwOSVersionInfoSize = sizeof(OSVERSIONINFO);
+ GetVersionEx(&osvi);
+
+ SYSTEM_INFO si;
+ GetSystemInfo(&si);
+ map<WORD,const char*> archs;
+ archs[PROCESSOR_ARCHITECTURE_AMD64] = "amd64";
+ archs[PROCESSOR_ARCHITECTURE_IA64] = "itanium";
+ archs[PROCESSOR_ARCHITECTURE_INTEL] = "x86";
+ archs[PROCESSOR_ARCHITECTURE_UNKNOWN] = "unknown";
+
+ stringstream out;
+ out << "OS info: "
+ << "Microsoft(TM) Windows(TM) " << osvi.dwMajorVersion << " "
+ << osvi.dwMinorVersion << " " << osvi.dwBuildNumber << " "
+ << osvi.szCSDVersion;
+ if (archs.find(si.wProcessorArchitecture) != archs.end())
+ out << " " << archs[si.wProcessorArchitecture];
+ out << "\n";
+
+ out << "Machine: " << si.dwProcessorType;
+
+ return out.str();
+}
+
+string offscreen_context_getinfo(OffscreenContext *ctx)
+{
+ stringstream out;
+ out << "GL context creator: WGL\n"
+ << "PNG generator: lodepng\n"
+ << get_os_info();
+ return out.str();
+}
+
+LRESULT CALLBACK WndProc(HWND hwnd, UINT message, WPARAM wparam, LPARAM lparam)
+{
+ return DefWindowProc( hwnd, message, wparam, lparam );
+}
+
+bool create_wgl_dummy_context(OffscreenContext &ctx)
+{
+ // this function alters ctx->window and ctx->openGLContext
+ // and ctx->dev_context if successfull
+
+ // create window
+
+ HINSTANCE inst = GetModuleHandle(0);
+ WNDCLASS wc;
+ ZeroMemory( &wc, sizeof( wc ) );
+ wc.style = CS_OWNDC;
+ wc.lpfnWndProc = WndProc;
+ wc.hInstance = inst;
+ wc.lpszClassName = (LPCWSTR)"OpenSCAD";
+ RegisterClass( &wc );
+
+ HWND window = CreateWindow( (LPCWSTR)"OpenSCAD", (LPCWSTR)"OpenSCAD",
+ WS_CAPTION | WS_POPUPWINDOW, //| WS_VISIBLE,
+ 0, 0, ctx.width, ctx.height, NULL, NULL, inst, NULL );
+
+ if ( window==NULL ) {
+ cerr << "MS GDI - CreateWindow failed\n";
+ return false;
+ }
+
+ // create WGL context, make current
+
+ PIXELFORMATDESCRIPTOR pixformat;
+ int chosenformat;
+ HDC dev_context = GetDC( window );
+ if ( dev_context == NULL ) {
+ cerr << "MS GDI - GetDC failed\n";
+ return false;
+ }
+
+ ZeroMemory( &pixformat, sizeof( pixformat ) );
+ pixformat.nSize = sizeof( pixformat );
+ pixformat.nVersion = 1;
+ pixformat.dwFlags = PFD_DRAW_TO_WINDOW | PFD_SUPPORT_OPENGL | PFD_DOUBLEBUFFER;
+ pixformat.iPixelType = PFD_TYPE_RGBA;
+ pixformat.cGreenBits = 8;
+ pixformat.cRedBits = 8;
+ pixformat.cBlueBits = 8;
+ pixformat.cAlphaBits = 8;
+ pixformat.cDepthBits = 24;
+ pixformat.cStencilBits = 8;
+
+ chosenformat = ChoosePixelFormat( dev_context, &pixformat );
+ if (chosenformat==0) {
+ cerr << "MS GDI - ChoosePixelFormat failed\n";
+ return false;
+ }
+
+ bool spfok = SetPixelFormat( dev_context, chosenformat, &pixformat );
+ if (!spfok) {
+ cerr << "MS GDI - SetPixelFormat failed\n";
+ return false;
+ }
+
+ HGLRC gl_render_context = wglCreateContext( dev_context );
+ if ( gl_render_context == NULL ) {
+ cerr << "MS WGL - wglCreateContext failed\n";
+ ReleaseDC( ctx.window, ctx.dev_context );
+ return false;
+ }
+
+ bool mcok = wglMakeCurrent( dev_context, gl_render_context );
+ if (!mcok) {
+ cerr << "MS WGL - wglMakeCurrent failed\n";
+ return false;
+ }
+
+ ctx.window = window;
+ ctx.dev_context = dev_context;
+ ctx.openGLContext = gl_render_context;
+
+ return true;
+}
+
+
+OffscreenContext *create_offscreen_context(int w, int h)
+{
+ OffscreenContext *ctx = new OffscreenContext;
+ offscreen_context_init( *ctx, w, h );
+
+ // Before an FBO can be setup, a WGL context must be created.
+ // This call alters ctx->window and ctx->openGLContext
+ // and ctx->dev_context if successfull
+ if (!create_wgl_dummy_context( *ctx )) {
+ return NULL;
+ }
+
+ GLenum err = glewInit(); // must come after Context creation and before FBO calls.
+ if (GLEW_OK != err) {
+ cerr << "Unable to init GLEW: " << glewGetErrorString(err) << "\n";
+ return NULL;
+ }
+ //cerr << glew_dump(0);
+
+ ctx->fbo = fbo_new();
+ if (!fbo_init(ctx->fbo, w, h)) {
+ return NULL;
+ }
+
+ return ctx;
+}
+
+bool teardown_offscreen_context(OffscreenContext *ctx)
+{
+ if (ctx) {
+ fbo_unbind(ctx->fbo);
+ fbo_delete(ctx->fbo);
+
+ wglMakeCurrent( NULL, NULL );
+ wglDeleteContext( ctx->openGLContext );
+ ReleaseDC( ctx->window, ctx->dev_context );
+
+ return true;
+ }
+ return false;
+}
+
+/*!
+ Capture framebuffer from OpenGL and write it to the given filename as PNG.
+*/
+bool save_framebuffer(OffscreenContext *ctx, const char *filename)
+{
+ wglSwapLayerBuffers( ctx->dev_context, WGL_SWAP_MAIN_PLANE );
+ if (!ctx || !filename) return false;
+ int samplesPerPixel = 4; // R, G, B and A
+ vector<GLubyte> pixels(ctx->width * ctx->height * samplesPerPixel);
+ glReadPixels(0, 0, ctx->width, ctx->height, GL_RGBA, GL_UNSIGNED_BYTE, &pixels[0]);
+
+ // Flip it vertically - images read from OpenGL buffers are upside-down
+ int rowBytes = samplesPerPixel * ctx->width;
+ unsigned char *flippedBuffer = (unsigned char *)malloc(rowBytes * ctx->height);
+ if (!flippedBuffer) {
+ std::cerr << "Unable to allocate flipped buffer for corrected image.";
+ return 1;
+ }
+ flip_image(&pixels[0], flippedBuffer, samplesPerPixel, ctx->width, ctx->height);
+
+ bool writeok = write_png(filename, flippedBuffer, ctx->width, ctx->height);
+
+ free(flippedBuffer);
+
+ return writeok;
+}
+
+void bind_offscreen_context(OffscreenContext *ctx)
+{
+ if (ctx) fbo_bind(ctx->fbo);
+}
diff --git a/src/OffscreenView.cc b/src/OffscreenView.cc
new file mode 100644
index 0000000..61d5818
--- /dev/null
+++ b/src/OffscreenView.cc
@@ -0,0 +1,170 @@
+#include <GL/glew.h>
+#include "OffscreenView.h"
+#include "system-gl.h"
+#include "renderer.h"
+#include <math.h>
+#include <stdio.h>
+#include <string.h>
+#include <cstdlib>
+#include <sstream>
+
+#define FAR_FAR_AWAY 100000.0
+
+OffscreenView::OffscreenView(size_t width, size_t height)
+ : orthomode(false), showaxes(false), showfaces(true), showedges(false),
+ object_rot(35, 0, 25), camera_eye(0, 0, 0), camera_center(0, 0, 0)
+{
+ for (int i = 0; i < 10; i++) this->shaderinfo[i] = 0;
+ this->ctx = create_offscreen_context(width, height);
+ if ( this->ctx == NULL ) throw -1;
+
+ initializeGL();
+ resizeGL(width, height);
+}
+
+OffscreenView::~OffscreenView()
+{
+ teardown_offscreen_context(this->ctx);
+}
+
+void OffscreenView::setRenderer(Renderer* r)
+{
+ this->renderer = r;
+}
+
+void OffscreenView::initializeGL()
+{
+ glEnable(GL_DEPTH_TEST);
+ glDepthRange(-FAR_FAR_AWAY, +FAR_FAR_AWAY);
+
+ glEnable(GL_BLEND);
+ glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
+
+ GLfloat light_diffuse[] = {1.0, 1.0, 1.0, 1.0};
+ GLfloat light_position0[] = {-1.0, -1.0, +1.0, 0.0};
+ GLfloat light_position1[] = {+1.0, +1.0, -1.0, 0.0};
+
+ glLightfv(GL_LIGHT0, GL_DIFFUSE, light_diffuse);
+ glLightfv(GL_LIGHT0, GL_POSITION, light_position0);
+ glEnable(GL_LIGHT0);
+ glLightfv(GL_LIGHT1, GL_DIFFUSE, light_diffuse);
+ glLightfv(GL_LIGHT1, GL_POSITION, light_position1);
+ glEnable(GL_LIGHT1);
+ glEnable(GL_LIGHTING);
+ glEnable(GL_NORMALIZE);
+
+ glColorMaterial(GL_FRONT_AND_BACK, GL_AMBIENT_AND_DIFFUSE);
+ glEnable(GL_COLOR_MATERIAL);
+
+
+}
+
+void OffscreenView::resizeGL(int w, int h)
+{
+ this->width = w;
+ this->height = h;
+ glViewport(0, 0, w, h);
+ w_h_ratio = sqrt((double)w / (double)h);
+}
+
+void OffscreenView::setupPerspective()
+{
+ glMatrixMode(GL_PROJECTION);
+ glLoadIdentity();
+ double dist = (this->camera_center - this->camera_eye).norm();
+ gluPerspective(45, w_h_ratio, 0.1*dist, 100*dist);
+}
+
+void OffscreenView::setupOrtho(bool offset)
+{
+ glMatrixMode(GL_PROJECTION);
+ glLoadIdentity();
+ if (offset) glTranslated(-0.8, -0.8, 0);
+ double l = (this->camera_center - this->camera_eye).norm() / 10;
+ glOrtho(-w_h_ratio*l, +w_h_ratio*l,
+ -(1/w_h_ratio)*l, +(1/w_h_ratio)*l,
+ -FAR_FAR_AWAY, +FAR_FAR_AWAY);
+}
+
+void OffscreenView::paintGL()
+{
+ glEnable(GL_LIGHTING);
+
+ if (orthomode) setupOrtho();
+ else setupPerspective();
+
+ glMatrixMode(GL_MODELVIEW);
+ glLoadIdentity();
+
+ glClearColor(1.0f, 1.0f, 0.92f, 1.0f);
+
+ glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT | GL_STENCIL_BUFFER_BIT);
+
+ gluLookAt(this->camera_eye[0], this->camera_eye[1], this->camera_eye[2],
+ this->camera_center[0], this->camera_center[1], this->camera_center[2],
+ 0.0, 0.0, 1.0);
+
+ // glRotated(object_rot[0], 1.0, 0.0, 0.0);
+ // glRotated(object_rot[1], 0.0, 1.0, 0.0);
+ // glRotated(object_rot[2], 0.0, 0.0, 1.0);
+
+ // Large gray axis cross inline with the model
+ // FIXME: This is always gray - adjust color to keep contrast with background
+ if (showaxes)
+ {
+ glLineWidth(1);
+ glColor3d(0.5, 0.5, 0.5);
+ glBegin(GL_LINES);
+ double l = 3*(this->camera_center - this->camera_eye).norm();
+ glVertex3d(-l, 0, 0);
+ glVertex3d(+l, 0, 0);
+ glVertex3d(0, -l, 0);
+ glVertex3d(0, +l, 0);
+ glVertex3d(0, 0, -l);
+ glVertex3d(0, 0, +l);
+ glEnd();
+ }
+
+ glDepthFunc(GL_LESS);
+ glCullFace(GL_BACK);
+ glDisable(GL_CULL_FACE);
+
+ glLineWidth(2);
+ glColor3d(1.0, 0.0, 0.0);
+
+ if (this->renderer) {
+ this->renderer->draw(showfaces, showedges);
+ }
+}
+
+bool OffscreenView::save(const char *filename)
+{
+ return save_framebuffer(this->ctx, filename);
+}
+
+std::string OffscreenView::getInfo()
+{
+ std::stringstream out;
+ GLint rbits, gbits, bbits, abits, dbits, sbits;
+ glGetIntegerv(GL_RED_BITS, &rbits);
+ glGetIntegerv(GL_GREEN_BITS, &gbits);
+ glGetIntegerv(GL_BLUE_BITS, &bbits);
+ glGetIntegerv(GL_ALPHA_BITS, &abits);
+ glGetIntegerv(GL_DEPTH_BITS, &dbits);
+ glGetIntegerv(GL_STENCIL_BITS, &sbits);
+
+ out << glew_dump(false)
+ << "FBO: RGBA(" << rbits << gbits << bbits << abits
+ << "), depth(" << dbits
+ << "), stencil(" << sbits << ")\n"
+ << offscreen_context_getinfo(this->ctx);
+
+ return out.str();
+}
+
+void OffscreenView::setCamera(const Eigen::Vector3d &pos, const Eigen::Vector3d &center)
+{
+ this->camera_eye = pos;
+ this->camera_center = center;
+}
+
diff --git a/src/OffscreenView.h b/src/OffscreenView.h
new file mode 100644
index 0000000..8b98b29
--- /dev/null
+++ b/src/OffscreenView.h
@@ -0,0 +1,45 @@
+#ifndef OFFSCREENVIEW_H_
+#define OFFSCREENVIEW_H_
+
+#include "OffscreenContext.h"
+#include <Eigen/Core>
+#include <Eigen/Geometry>
+#include <string>
+#ifndef _MSC_VER
+#include <stdint.h>
+#endif
+
+class OffscreenView
+{
+public:
+ OffscreenView(size_t width, size_t height);
+ ~OffscreenView();
+ void setRenderer(class Renderer* r);
+
+ void setCamera(const Eigen::Vector3d &pos, const Eigen::Vector3d &center);
+ void initializeGL();
+ void resizeGL(int w, int h);
+ void setupPerspective();
+ void setupOrtho(bool offset=false);
+ void paintGL();
+ bool save(const char *filename);
+ std::string getInfo();
+
+ GLint shaderinfo[11];
+ OffscreenContext *ctx;
+ size_t width;
+ size_t height;
+private:
+ Renderer *renderer;
+ double w_h_ratio;
+ Eigen::Vector3d object_rot;
+ Eigen::Vector3d camera_eye;
+ Eigen::Vector3d camera_center;
+
+ bool orthomode;
+ bool showaxes;
+ bool showfaces;
+ bool showedges;
+};
+
+#endif
diff --git a/src/fbo.cc b/src/fbo.cc
new file mode 100644
index 0000000..a6677c1
--- /dev/null
+++ b/src/fbo.cc
@@ -0,0 +1,237 @@
+#include "fbo.h"
+#include "system-gl.h"
+#include <stdio.h>
+#include <iostream>
+using namespace std;
+
+fbo_t *fbo_new()
+{
+ fbo_t *fbo = new fbo_t;
+ fbo->fbo_id = 0;
+ fbo->old_fbo_id = 0;
+ fbo->renderbuf_id = 0;
+ fbo->depthbuf_id = 0;
+
+ return fbo;
+}
+
+bool use_ext()
+{
+ // do we need to use the EXT or ARB version?
+ if (!glewIsSupported("GL_ARB_framebuffer_object") &&
+ glewIsSupported("GL_EXT_framebuffer_object")) {
+ return true;
+ } else {
+ return false;
+ }
+}
+
+bool check_fbo_status()
+{
+ /* This code is based on user V-man code from
+ http://www.opengl.org/wiki/GL_EXT_framebuffer_multisample
+ See also: http://www.songho.ca/opengl/gl_fbo.html */
+ GLenum status;
+ bool result = false;
+ if (use_ext())
+ status = glCheckFramebufferStatusEXT(GL_FRAMEBUFFER_EXT);
+ else
+ status = glCheckFramebufferStatus(GL_FRAMEBUFFER);
+
+ if (report_glerror("checking framebuffer status")) return false;
+
+ if (status == GL_FRAMEBUFFER_COMPLETE)
+ result = true;
+ else if (status == GL_FRAMEBUFFER_UNSUPPORTED)
+ cerr << "GL_FRAMEBUFFER_UNSUPPORTED\n";
+ else if (status == GL_FRAMEBUFFER_INCOMPLETE_ATTACHMENT)
+ cerr << "GL_FRAMEBUFFER_INCOMPLETE_ATTACHMENT\n";
+ else if (status == GL_FRAMEBUFFER_INCOMPLETE_MISSING_ATTACHMENT)
+ cerr << "GL_FRAMEBUFFER_INCOMPLETE_MISSING_ATTACHMENT\n";
+ else if (status == GL_FRAMEBUFFER_INCOMPLETE_DIMENSIONS_EXT)
+ cerr << "GL_FRAMEBUFFER_INCOMPLETE_DIMENSIONS_EXT\n";
+ else if (status == GL_FRAMEBUFFER_INCOMPLETE_FORMATS_EXT)
+ cerr << "GL_FRAMEBUFFER_INCOMPLETE_FORMATS_EXT\n";
+ else if (status == GL_FRAMEBUFFER_INCOMPLETE_DRAW_BUFFER_EXT)
+ cerr << "GL_FRAMEBUFFER_INCOMPLETE_DRAW_BUFFER_EXT\n";
+ else if (status == GL_FRAMEBUFFER_INCOMPLETE_READ_BUFFER_EXT)
+ cerr << "GL_FRAMEBUFFER_INCOMPLETE_READ_BUFFER_EXT\n";
+ else if (status == GL_FRAMEBUFFER_INCOMPLETE_MULTISAMPLE_EXT)
+ cerr << "GL_FRAMEBUFFER_INCOMPLETE_MULTISAMPLE_EXT\n";
+ else
+ cerr << "Unknown Code: glCheckFramebufferStatusEXT returned %i\n",status;
+ return result;
+}
+
+bool fbo_ext_init(fbo_t *fbo, size_t width, size_t height)
+{
+ // Generate and bind FBO
+ glGenFramebuffersEXT(1, &fbo->fbo_id);
+ if (report_glerror("glGenFramebuffersEXT")) return false;
+ glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, fbo->fbo_id);
+ if (report_glerror("glBindFramebufferEXT")) return false;
+
+ // Generate depth and render buffers
+ glGenRenderbuffersEXT(1, &fbo->depthbuf_id);
+ glGenRenderbuffersEXT(1, &fbo->renderbuf_id);
+
+ // Create buffers with correct size
+ if (!fbo_resize(fbo, width, height)) return false;
+
+ // Attach render and depth buffers
+ glFramebufferRenderbufferEXT(GL_FRAMEBUFFER_EXT, GL_COLOR_ATTACHMENT0_EXT,
+ GL_RENDERBUFFER_EXT, fbo->renderbuf_id);
+ if (report_glerror("specifying color render buffer EXT")) return false;
+
+
+ if (!check_fbo_status()) {
+ cerr << "Problem with OpenGL EXT framebuffer after specifying color render buffer.\n";
+ return false;
+ }
+
+ if (glewIsSupported("GL_EXT_packed_depth_stencil")) {
+ glFramebufferRenderbufferEXT(GL_FRAMEBUFFER_EXT, GL_DEPTH_ATTACHMENT_EXT,
+ GL_RENDERBUFFER_EXT, fbo->depthbuf_id);
+ if (report_glerror("specifying depth render buffer EXT")) return false;
+
+ glFramebufferRenderbufferEXT(GL_FRAMEBUFFER_EXT, GL_STENCIL_ATTACHMENT_EXT,
+ GL_RENDERBUFFER_EXT, fbo->depthbuf_id);
+ if (report_glerror("specifying stencil render buffer EXT")) return false;
+
+ if (!check_fbo_status()) {
+ cerr << "Problem with OpenGL EXT framebuffer after specifying depth render buffer.\n";
+ return false;
+ }
+ }
+ else {
+ cerr << "Warning: Cannot create stencil buffer (GL_EXT_packed_depth_stencil not supported)\n";
+ glFramebufferRenderbufferEXT(GL_FRAMEBUFFER_EXT, GL_DEPTH_ATTACHMENT_EXT,
+ GL_RENDERBUFFER_EXT, fbo->depthbuf_id);
+ if (report_glerror("specifying depth render buffer EXT")) return false;
+
+ if (!check_fbo_status()) {
+ cerr << "Problem with OpenGL EXT framebuffer after specifying depth stencil render buffer.\n";
+ return false;
+ }
+ }
+
+ return true;
+}
+
+bool fbo_arb_init(fbo_t *fbo, size_t width, size_t height)
+{
+ // Generate and bind FBO
+ glGenFramebuffers(1, &fbo->fbo_id);
+ if (report_glerror("glGenFramebuffers")) return false;
+ glBindFramebuffer(GL_FRAMEBUFFER, fbo->fbo_id);
+ if (report_glerror("glBindFramebuffer")) return false;
+
+ // Generate depth and render buffers
+ glGenRenderbuffers(1, &fbo->depthbuf_id);
+ glGenRenderbuffers(1, &fbo->renderbuf_id);
+
+ // Create buffers with correct size
+ if (!fbo_resize(fbo, width, height)) return false;
+
+ // Attach render and depth buffers
+ glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0,
+ GL_RENDERBUFFER, fbo->renderbuf_id);
+ if (report_glerror("specifying color render buffer")) return false;
+
+ if (!check_fbo_status()) {
+ cerr << "Problem with OpenGL framebuffer after specifying color render buffer.\n";
+ return false;
+ }
+
+ //glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_DEPTH_STENCIL_ATTACHMENT,
+ // to prevent Mesa's software renderer from crashing, do this in two stages.
+ // ie. instead of using GL_DEPTH_STENCIL_ATTACHMENT, do DEPTH then STENCIL.
+ glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_DEPTH_ATTACHMENT,
+ GL_RENDERBUFFER, fbo->depthbuf_id);
+ glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_STENCIL_ATTACHMENT,
+ GL_RENDERBUFFER, fbo->depthbuf_id);
+ if (report_glerror("specifying depth stencil render buffer")) return false;
+
+ if (!check_fbo_status()) {
+ cerr << "Problem with OpenGL framebuffer after specifying depth render buffer.\n";
+ return false;
+ }
+
+ return true;
+}
+
+
+bool fbo_init(fbo_t *fbo, size_t width, size_t height)
+{
+ /*
+ Some OpenGL drivers include the framebuffer functions but not with
+ core or ARB names, only with the EXT name. This has been worked-around
+ by deciding at runtime, using GLEW, which version needs to be used. See also:
+
+ http://www.opengl.org/wiki/Framebuffer_Object
+ http://stackoverflow.com/questions/6912988/glgenframebuffers-or-glgenframebuffersex
+ http://www.devmaster.net/forums/showthread.php?t=10967
+ */
+
+ bool result = false;
+ if (glewIsSupported("GL_ARB_framebuffer_object"))
+ result = fbo_arb_init(fbo, width, height);
+ else if (use_ext())
+ result = fbo_ext_init(fbo, width, height);
+ else
+ cerr << "Framebuffer Object extension not found by GLEW\n";
+ return result;
+}
+
+bool fbo_resize(fbo_t *fbo, size_t width, size_t height)
+{
+ if (use_ext()) {
+ glBindRenderbufferEXT(GL_RENDERBUFFER, fbo->depthbuf_id);
+ if (glewIsSupported("GL_EXT_packed_depth_stencil")) {
+ glRenderbufferStorageEXT(GL_RENDERBUFFER, GL_DEPTH24_STENCIL8, width, height);
+ if (report_glerror("creating EXT depth stencil render buffer")) return false;
+ }
+ else {
+ glRenderbufferStorageEXT(GL_RENDERBUFFER, GL_DEPTH_COMPONENT24, width, height);
+ if (report_glerror("creating EXT depth render buffer")) return false;
+ }
+
+ glBindRenderbufferEXT(GL_RENDERBUFFER, fbo->renderbuf_id);
+ glRenderbufferStorageEXT(GL_RENDERBUFFER, GL_RGBA8, width, height);
+ if (report_glerror("creating EXT color render buffer")) return false;
+ } else {
+ glBindRenderbuffer(GL_RENDERBUFFER, fbo->renderbuf_id);
+ glRenderbufferStorage(GL_RENDERBUFFER, GL_RGBA8, width, height);
+ if (report_glerror("creating color render buffer")) return false;
+
+ glBindRenderbuffer(GL_RENDERBUFFER, fbo->depthbuf_id);
+ glRenderbufferStorage(GL_RENDERBUFFER, GL_DEPTH24_STENCIL8, width, height);
+ if (report_glerror("creating depth stencil render buffer")) return false;
+
+ }
+
+ return true;
+}
+
+void fbo_delete(fbo_t *fbo)
+{
+ delete fbo;
+}
+
+GLuint fbo_bind(fbo_t *fbo)
+{
+ glGetIntegerv(GL_FRAMEBUFFER_BINDING, (GLint *)&fbo->old_fbo_id);
+ if (use_ext())
+ glBindFramebufferEXT(GL_FRAMEBUFFER, fbo->fbo_id);
+ else
+ glBindFramebuffer(GL_FRAMEBUFFER, fbo->fbo_id);
+ return fbo->old_fbo_id;
+}
+
+void fbo_unbind(fbo_t *fbo)
+{
+ if (use_ext())
+ glBindFramebufferEXT(GL_FRAMEBUFFER, fbo->old_fbo_id);
+ else
+ glBindFramebuffer(GL_FRAMEBUFFER, fbo->old_fbo_id);
+}
diff --git a/src/fbo.h b/src/fbo.h
new file mode 100644
index 0000000..943862f
--- /dev/null
+++ b/src/fbo.h
@@ -0,0 +1,25 @@
+#ifndef FBO_H_
+#define FBO_H_
+
+#include "system-gl.h"
+#include <stddef.h> // size_t
+
+struct fbo_t
+{
+ GLuint fbo_id;
+ GLuint old_fbo_id;
+
+ GLuint renderbuf_id;
+ GLuint depthbuf_id;
+};
+
+fbo_t *fbo_new();
+bool fbo_init(fbo_t *fbo, size_t width, size_t height);
+bool fbo_resize(fbo_t *fbo, size_t width, size_t height);
+void fbo_delete(fbo_t *fbo);
+GLuint fbo_bind(fbo_t *fbo);
+void fbo_unbind(fbo_t *fbo);
+
+bool REPORTGLERROR(const char * task);
+
+#endif
diff --git a/src/imageutils-lodepng.cc b/src/imageutils-lodepng.cc
new file mode 100644
index 0000000..8460d9e
--- /dev/null
+++ b/src/imageutils-lodepng.cc
@@ -0,0 +1,24 @@
+#include "lodepng.h"
+#include <stdio.h>
+
+bool write_png(const char *filename, unsigned char *pixels, int width, int height)
+{
+ //encoder.settings.zlibsettings.windowSize = 2048;
+ //LodePNG_Text_add(&encoder.infoPng.text, "Comment", "Created with LodePNG");
+
+ size_t dataout_size = -1;
+ unsigned char *dataout = (unsigned char *)malloc(width*height*4);
+ LodePNG_encode(&dataout, &dataout_size, pixels, width, height, LCT_RGBA, 8);
+ //LodePNG_saveFile(dataout, dataout_size, "blah2.png");
+
+ FILE *f = fopen(filename, "wb");
+ if (!f) {
+ free(dataout);
+ return false;
+ }
+
+ fwrite(dataout, 1, dataout_size, f);
+ fclose(f);
+ free(dataout);
+ return true;
+}
diff --git a/src/imageutils-macosx.cc b/src/imageutils-macosx.cc
new file mode 100644
index 0000000..404052f
--- /dev/null
+++ b/src/imageutils-macosx.cc
@@ -0,0 +1,64 @@
+#include <ApplicationServices/ApplicationServices.h>
+#include <iostream>
+
+bool write_png(const char *filename, unsigned char *pixels, int width, int height)
+{
+ size_t rowBytes = width * 4;
+// CGColorSpaceRef colorSpace = CGColorSpaceCreateWithName(kCGColorSpaceGenericRGB);
+ CGColorSpaceRef colorSpace = CGColorSpaceCreateDeviceRGB();
+ CGBitmapInfo bitmapInfo = kCGImageAlphaNoneSkipLast | kCGBitmapByteOrder32Big; // BGRA
+ int bitsPerComponent = 8;
+ CGContextRef contextRef = CGBitmapContextCreate(pixels, width, height,
+ bitsPerComponent, rowBytes,
+ colorSpace, bitmapInfo);
+ if (!contextRef) {
+ std::cerr << "Unable to create CGContextRef.";
+ return false;
+ }
+
+ CGImageRef imageRef = CGBitmapContextCreateImage(contextRef);
+ if (!imageRef) {
+ std::cerr << "Unable to create CGImageRef.";
+ return false;
+ }
+
+ CFStringRef fname = CFStringCreateWithCString(kCFAllocatorDefault, filename, kCFStringEncodingUTF8);
+ CFURLRef fileURL = CFURLCreateWithFileSystemPath(kCFAllocatorDefault,
+ fname, kCFURLPOSIXPathStyle, false);
+ if (!fileURL) {
+ std::cerr << "Unable to create file URL ref.";
+ return false;
+ }
+
+ CGDataConsumerRef dataconsumer = CGDataConsumerCreateWithURL(fileURL);
+ CFIndex fileImageIndex = 1;
+ CFMutableDictionaryRef fileDict = NULL;
+ CFStringRef fileUTType = kUTTypePNG;
+ // Create an image destination opaque reference for authoring an image file
+ CGImageDestinationRef imageDest = CGImageDestinationCreateWithDataConsumer(dataconsumer,
+ fileUTType,
+ fileImageIndex,
+ fileDict);
+ if (!imageDest) {
+ std::cerr << "Unable to create CGImageDestinationRef.";
+ return false;
+ }
+
+ CFIndex capacity = 1;
+ CFMutableDictionaryRef imageProps =
+ CFDictionaryCreateMutable(kCFAllocatorDefault,
+ capacity,
+ &kCFTypeDictionaryKeyCallBacks,
+ &kCFTypeDictionaryValueCallBacks);
+ CGImageDestinationAddImage(imageDest, imageRef, imageProps);
+ CGImageDestinationFinalize(imageDest);
+
+ CFRelease(imageDest);
+ CFRelease(dataconsumer);
+ CFRelease(fileURL);
+ CFRelease(fname);
+ CFRelease(imageProps);
+ CGColorSpaceRelease(colorSpace);
+ CGImageRelease(imageRef);
+ return true;
+}
diff --git a/src/imageutils.cc b/src/imageutils.cc
new file mode 100644
index 0000000..e15ba2b
--- /dev/null
+++ b/src/imageutils.cc
@@ -0,0 +1,16 @@
+#include "imageutils.h"
+#include <string.h>
+
+void flip_image(const unsigned char *src, unsigned char *dst, size_t pixelsize, size_t width, size_t height)
+{
+ size_t rowBytes = pixelsize * width;
+ for (size_t i = 0 ; i < height ; i++) {
+ memmove(dst + (height - i - 1) * rowBytes, src + i * rowBytes, rowBytes);
+ }
+}
+
+#ifdef __APPLE__
+#include "imageutils-macosx.cc"
+#else
+#include "imageutils-lodepng.cc"
+#endif
diff --git a/src/imageutils.h b/src/imageutils.h
new file mode 100644
index 0000000..72602a2
--- /dev/null
+++ b/src/imageutils.h
@@ -0,0 +1,9 @@
+#ifndef IMAGEUTILS_H_
+#define IMAGEUTILS_H_
+
+#include <stdlib.h>
+
+bool write_png(const char *filename, unsigned char *pixels, int width, int height);
+void flip_image(const unsigned char *src, unsigned char *dst, size_t pixelsize, size_t width, size_t height);
+
+#endif
diff --git a/src/lodepng.cpp b/src/lodepng.cpp
new file mode 100644
index 0000000..831194f
--- /dev/null
+++ b/src/lodepng.cpp
@@ -0,0 +1,5797 @@
+/*
+LodePNG version 20110908
+
+Copyright (c) 2005-2011 Lode Vandevenne
+
+This software is provided 'as-is', without any express or implied
+warranty. In no event will the authors be held liable for any damages
+arising from the use of this software.
+
+Permission is granted to anyone to use this software for any purpose,
+including commercial applications, and to alter it and redistribute it
+freely, subject to the following restrictions:
+
+ 1. The origin of this software must not be misrepresented; you must not
+ claim that you wrote the original software. If you use this software
+ in a product, an acknowledgment in the product documentation would be
+ appreciated but is not required.
+
+ 2. Altered source versions must be plainly marked as such, and must not be
+ misrepresented as being the original software.
+
+ 3. This notice may not be removed or altered from any source
+ distribution.
+*/
+
+/*
+The manual and changelog are in the header file "lodepng.h"
+Rename this file to lodepng.cpp to use it for C++, or to lodepng.c to use it for C.
+*/
+
+#include "lodepng.h"
+
+#include <stdio.h>
+#include <stdlib.h>
+
+#ifdef __cplusplus
+#include <fstream>
+#endif /*__cplusplus*/
+
+#define VERSION_STRING "20110908"
+
+/*
+This source file is built up in the following large parts. The code sections
+with the "LODEPNG_COMPILE_" #defines divide this up further in an intermixed way.
+-Tools for C and common code for PNG and Zlib
+-C Code for Zlib (huffman, deflate, ...)
+-C Code for PNG (file format chunks, adam7, PNG filters, color conversions, ...)
+-The C++ wrapper around all of the above
+*/
+
+/* ////////////////////////////////////////////////////////////////////////// */
+/* ////////////////////////////////////////////////////////////////////////// */
+/* // Tools for C, and common code for PNG and Zlib. // */
+/* ////////////////////////////////////////////////////////////////////////// */
+/* ////////////////////////////////////////////////////////////////////////// */
+
+/*
+Often in case of an error a value is assigned to a variable and then it breaks
+out of a loop (to go to the cleanup phase of a function). This macro does that.
+It makes the error handling code shorter and more readable.
+
+Example: if(!uivector_resizev(&frequencies_ll, 286, 0)) ERROR_BREAK(9924);
+*/
+#define CERROR_BREAK(errorvar, code)\
+{\
+ errorvar = code;\
+ break;\
+}
+
+/*version of CERROR_BREAK that assumes the common case where the error variable is named "error"*/
+#define ERROR_BREAK(code) CERROR_BREAK(error, code)
+
+/*
+About vector, uivector, ucvector and string:
+-All of them wrap dynamic arrays or text strings in a similar way.
+-LodePNG was originally written in C++. The vectors replace the std::vectors that were used in the C++ version.
+-The string tools are made to avoid problems with compilers that declare things like strncat as deprecated.
+-They're not used in the interface, only internally in this file as static functions.
+-As with many other structs in this file, the init and cleanup functions serve as ctor and dtor.
+*/
+
+#ifdef LODEPNG_COMPILE_ZLIB
+#ifdef LODEPNG_COMPILE_ENCODER
+
+typedef struct vector /*dynamic vector of void* pointers. This one is used only by the deflate compressor*/
+{
+ void* data;
+ size_t size; /*in groups of bytes depending on type*/
+ size_t allocsize; /*in bytes*/
+ unsigned typesize; /*sizeof the type you store in data*/
+} vector;
+
+static unsigned vector_resize(vector* p, size_t size) /*returns 1 if success, 0 if failure ==> nothing done*/
+{
+ if(size * p->typesize > p->allocsize)
+ {
+ size_t newsize = size * p->typesize * 2;
+ void* data = realloc(p->data, newsize);
+ if(data)
+ {
+ p->allocsize = newsize;
+ p->data = data;
+ p->size = size;
+ }
+ else return 0;
+ }
+ else p->size = size;
+ return 1;
+}
+
+/*resize and use destructor on elements if it gets smaller*/
+static unsigned vector_resized(vector* p, size_t size, void dtor(void*))
+{
+ size_t i;
+ if(size < p->size)
+ {
+ for(i = size; i < p->size; i++)
+ {
+ dtor(&((char*)(p->data))[i * p->typesize]);
+ }
+ }
+ return vector_resize(p, size);
+}
+
+static void vector_cleanup(void* p)
+{
+ ((vector*)p)->size = ((vector*)p)->allocsize = 0;
+ free(((vector*)p)->data);
+ ((vector*)p)->data = NULL;
+}
+
+static void vector_cleanupd(vector* p, void dtor(void*)) /*clear and use destructor on elements*/
+{
+ vector_resized(p, 0, dtor);
+ vector_cleanup(p);
+}
+
+static void vector_init(vector* p, unsigned typesize)
+{
+ p->data = NULL;
+ p->size = p->allocsize = 0;
+ p->typesize = typesize;
+}
+
+static void vector_swap(vector* p, vector* q) /*they're supposed to have the same typesize*/
+{
+ size_t tmp;
+ void* tmpp;
+ tmp = p->size; p->size = q->size; q->size = tmp;
+ tmp = p->allocsize; p->allocsize = q->allocsize; q->allocsize = tmp;
+ tmpp = p->data; p->data = q->data; q->data = tmpp;
+}
+
+static void* vector_get(vector* p, size_t index)
+{
+ return &((char*)p->data)[index * p->typesize];
+}
+
+#endif /*LODEPNG_COMPILE_ENCODER*/
+#endif /*LODEPNG_COMPILE_ZLIB*/
+
+/* /////////////////////////////////////////////////////////////////////////// */
+
+#ifdef LODEPNG_COMPILE_ZLIB
+/*dynamic vector of unsigned ints*/
+typedef struct uivector
+{
+ unsigned* data;
+ size_t size; /*size in number of unsigned longs*/
+ size_t allocsize; /*allocated size in bytes*/
+} uivector;
+
+static void uivector_cleanup(void* p)
+{
+ ((uivector*)p)->size = ((uivector*)p)->allocsize = 0;
+ free(((uivector*)p)->data);
+ ((uivector*)p)->data = NULL;
+}
+
+/*returns 1 if success, 0 if failure ==> nothing done*/
+static unsigned uivector_resize(uivector* p, size_t size)
+{
+ if(size * sizeof(unsigned) > p->allocsize)
+ {
+ size_t newsize = size * sizeof(unsigned) * 2;
+ void* data = realloc(p->data, newsize);
+ if(data)
+ {
+ p->allocsize = newsize;
+ p->data = (unsigned*)data;
+ p->size = size;
+ }
+ else return 0;
+ }
+ else p->size = size;
+ return 1;
+}
+
+/*resize and give all new elements the value*/
+static unsigned uivector_resizev(uivector* p, size_t size, unsigned value)
+{
+ size_t oldsize = p->size, i;
+ if(!uivector_resize(p, size)) return 0;
+ for(i = oldsize; i < size; i++) p->data[i] = value;
+ return 1;
+}
+
+static void uivector_init(uivector* p)
+{
+ p->data = NULL;
+ p->size = p->allocsize = 0;
+}
+
+#ifdef LODEPNG_COMPILE_ENCODER
+/*returns 1 if success, 0 if failure ==> nothing done*/
+static unsigned uivector_push_back(uivector* p, unsigned c)
+{
+ if(!uivector_resize(p, p->size + 1)) return 0;
+ p->data[p->size - 1] = c;
+ return 1;
+}
+
+/*copy q to p, returns 1 if success, 0 if failure ==> nothing done*/
+static unsigned uivector_copy(uivector* p, const uivector* q)
+{
+ size_t i;
+ if(!uivector_resize(p, q->size)) return 0;
+ for(i = 0; i < q->size; i++) p->data[i] = q->data[i];
+ return 1;
+}
+
+static void uivector_swap(uivector* p, uivector* q)
+{
+ size_t tmp;
+ unsigned* tmpp;
+ tmp = p->size; p->size = q->size; q->size = tmp;
+ tmp = p->allocsize; p->allocsize = q->allocsize; q->allocsize = tmp;
+ tmpp = p->data; p->data = q->data; q->data = tmpp;
+}
+#endif /*LODEPNG_COMPILE_ENCODER*/
+#endif /*LODEPNG_COMPILE_ZLIB*/
+
+/* /////////////////////////////////////////////////////////////////////////// */
+
+/*dynamic vector of unsigned chars*/
+typedef struct ucvector
+{
+ unsigned char* data;
+ size_t size; /*used size*/
+ size_t allocsize; /*allocated size*/
+} ucvector;
+
+static void ucvector_cleanup(void* p)
+{
+ ((ucvector*)p)->size = ((ucvector*)p)->allocsize = 0;
+ free(((ucvector*)p)->data);
+ ((ucvector*)p)->data = NULL;
+}
+
+/*returns 1 if success, 0 if failure ==> nothing done*/
+static unsigned ucvector_resize(ucvector* p, size_t size)
+{
+ if(size * sizeof(unsigned char) > p->allocsize)
+ {
+ size_t newsize = size * sizeof(unsigned char) * 2;
+ void* data = realloc(p->data, newsize);
+ if(data)
+ {
+ p->allocsize = newsize;
+ p->data = (unsigned char*)data;
+ p->size = size;
+ }
+ else return 0; /*error: not enough memory*/
+ }
+ else p->size = size;
+ return 1;
+}
+
+#ifdef LODEPNG_COMPILE_DECODER
+#ifdef LODEPNG_COMPILE_PNG
+/*resize and give all new elements the value*/
+static unsigned ucvector_resizev(ucvector* p, size_t size, unsigned char value)
+{
+ size_t oldsize = p->size, i;
+ if(!ucvector_resize(p, size)) return 0;
+ for(i = oldsize; i < size; i++) p->data[i] = value;
+ return 1;
+}
+#endif /*LODEPNG_COMPILE_PNG*/
+#endif /*LODEPNG_COMPILE_DECODER*/
+
+static void ucvector_init(ucvector* p)
+{
+ p->data = NULL;
+ p->size = p->allocsize = 0;
+}
+
+#ifdef LODEPNG_COMPILE_ZLIB
+/*you can both convert from vector to buffer&size and vica versa. If you use
+init_buffer to take over a buffer and size, it is not needed to use cleanup*/
+static void ucvector_init_buffer(ucvector* p, unsigned char* buffer, size_t size)
+{
+ p->data = buffer;
+ p->allocsize = p->size = size;
+}
+#endif /*LODEPNG_COMPILE_ZLIB*/
+
+#ifdef LODEPNG_COMPILE_ENCODER
+/*returns 1 if success, 0 if failure ==> nothing done*/
+static unsigned ucvector_push_back(ucvector* p, unsigned char c)
+{
+ if(!ucvector_resize(p, p->size + 1)) return 0;
+ p->data[p->size - 1] = c;
+ return 1;
+}
+#endif /*LODEPNG_COMPILE_ENCODER*/
+
+
+/* ////////////////////////////////////////////////////////////////////////// */
+
+#ifdef LODEPNG_COMPILE_PNG
+#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS
+/*returns 1 if success, 0 if failure ==> nothing done*/
+static unsigned string_resize(char** out, size_t size)
+{
+ char* data = (char*)realloc(*out, size + 1);
+ if(data)
+ {
+ data[size] = 0; /*null termination char*/
+ *out = data;
+ }
+ return data != 0;
+}
+
+/*init a {char*, size_t} pair for use as string*/
+static void string_init(char** out)
+{
+ *out = NULL;
+ string_resize(out, 0);
+}
+
+/*free the above pair again*/
+static void string_cleanup(char** out)
+{
+ free(*out);
+ *out = NULL;
+}
+
+static void string_set(char** out, const char* in)
+{
+ size_t insize = strlen(in), i = 0;
+ if(string_resize(out, insize))
+ {
+ for(i = 0; i < insize; i++)
+ {
+ (*out)[i] = in[i];
+ }
+ }
+}
+#endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/
+#endif /*LODEPNG_COMPILE_PNG*/
+
+/* ////////////////////////////////////////////////////////////////////////// */
+
+unsigned LodePNG_read32bitInt(const unsigned char* buffer)
+{
+ return (buffer[0] << 24) | (buffer[1] << 16) | (buffer[2] << 8) | buffer[3];
+}
+
+/*buffer must have at least 4 allocated bytes available*/
+static void LodePNG_set32bitInt(unsigned char* buffer, unsigned value)
+{
+ buffer[0] = (unsigned char)((value >> 24) & 0xff);
+ buffer[1] = (unsigned char)((value >> 16) & 0xff);
+ buffer[2] = (unsigned char)((value >> 8) & 0xff);
+ buffer[3] = (unsigned char)((value ) & 0xff);
+}
+
+#ifdef LODEPNG_COMPILE_ENCODER
+static void LodePNG_add32bitInt(ucvector* buffer, unsigned value)
+{
+ ucvector_resize(buffer, buffer->size + 4); /*todo: give error if resize failed*/
+ LodePNG_set32bitInt(&buffer->data[buffer->size - 4], value);
+}
+#endif /*LODEPNG_COMPILE_ENCODER*/
+
+/* ////////////////////////////////////////////////////////////////////////// */
+/* / File IO / */
+/* ////////////////////////////////////////////////////////////////////////// */
+
+#ifdef LODEPNG_COMPILE_DISK
+
+unsigned LodePNG_loadFile(unsigned char** out, size_t* outsize, const char* filename)
+{
+ FILE* file;
+ long size;
+
+ /*provide some proper output values if error will happen*/
+ *out = 0;
+ *outsize = 0;
+
+ file = fopen(filename, "rb");
+ if(!file) return 78;
+
+ /*get filesize:*/
+ fseek(file , 0 , SEEK_END);
+ size = ftell(file);
+ rewind(file);
+
+ /*read contents of the file into the vector*/
+ *outsize = 0;
+ *out = (unsigned char*)malloc((size_t)size);
+ if(size && (*out)) (*outsize) = fread(*out, 1, (size_t)size, file);
+
+ fclose(file);
+ if(!(*out) && size) return 9900; /*the above malloc failed*/
+ return 0;
+}
+
+/*write given buffer to the file, overwriting the file, it doesn't append to it.*/
+unsigned LodePNG_saveFile(const unsigned char* buffer, size_t buffersize, const char* filename)
+{
+ FILE* file;
+ file = fopen(filename, "wb" );
+ if(!file) return 79;
+ fwrite((char*)buffer , 1 , buffersize, file);
+ fclose(file);
+ return 0;
+}
+
+#endif /*LODEPNG_COMPILE_DISK*/
+
+/* ////////////////////////////////////////////////////////////////////////// */
+/* ////////////////////////////////////////////////////////////////////////// */
+/* // End of common code and tools. Begin of Zlib related code. // */
+/* ////////////////////////////////////////////////////////////////////////// */
+/* ////////////////////////////////////////////////////////////////////////// */
+
+#ifdef LODEPNG_COMPILE_ZLIB
+
+/* ////////////////////////////////////////////////////////////////////////// */
+/* / Reading and writing single bits and bytes from/to stream for Deflate / */
+/* ////////////////////////////////////////////////////////////////////////// */
+
+#ifdef LODEPNG_COMPILE_ENCODER
+/*TODO: this ignores potential out of memory errors*/
+static void addBitToStream(size_t* bitpointer, ucvector* bitstream, unsigned char bit)
+{
+ /*add a new byte at the end*/
+ if((*bitpointer) % 8 == 0) ucvector_push_back(bitstream, (unsigned char)0);
+ /*earlier bit of huffman code is in a lesser significant bit of an earlier byte*/
+ (bitstream->data[bitstream->size - 1]) |= (bit << ((*bitpointer) & 0x7));
+ (*bitpointer)++;
+}
+
+static void addBitsToStream(size_t* bitpointer, ucvector* bitstream, unsigned value, size_t nbits)
+{
+ size_t i;
+ for(i = 0; i < nbits; i++) addBitToStream(bitpointer, bitstream, (unsigned char)((value >> i) & 1));
+}
+
+static void addBitsToStreamReversed(size_t* bitpointer, ucvector* bitstream, unsigned value, size_t nbits)
+{
+ size_t i;
+ for(i = 0; i < nbits; i++) addBitToStream(bitpointer, bitstream, (unsigned char)((value >> (nbits - 1 - i)) & 1));
+}
+#endif /*LODEPNG_COMPILE_ENCODER*/
+
+#ifdef LODEPNG_COMPILE_DECODER
+
+#define READBIT(bitpointer, bitstream) ((bitstream[bitpointer >> 3] >> (bitpointer & 0x7)) & (unsigned char)1)
+
+static unsigned char readBitFromStream(size_t* bitpointer, const unsigned char* bitstream)
+{
+ unsigned char result = (unsigned char)(READBIT(*bitpointer, bitstream));
+ (*bitpointer)++;
+ return result;
+}
+
+static unsigned readBitsFromStream(size_t* bitpointer, const unsigned char* bitstream, size_t nbits)
+{
+ unsigned result = 0, i;
+ for(i = 0; i < nbits; i++)
+ {
+ result += ((unsigned)READBIT(*bitpointer, bitstream)) << i;
+ (*bitpointer)++;
+ }
+ return result;
+}
+#endif /*LODEPNG_COMPILE_DECODER*/
+
+/* ////////////////////////////////////////////////////////////////////////// */
+/* / Deflate - Huffman / */
+/* ////////////////////////////////////////////////////////////////////////// */
+
+#define FIRST_LENGTH_CODE_INDEX 257
+#define LAST_LENGTH_CODE_INDEX 285
+/*256 literals, the end code, some length codes, and 2 unused codes*/
+#define NUM_DEFLATE_CODE_SYMBOLS 288
+/*the distance codes have their own symbols, 30 used, 2 unused*/
+#define NUM_DISTANCE_SYMBOLS 32
+/*the code length codes. 0-15: code lengths, 16: copy previous 3-6 times, 17: 3-10 zeros, 18: 11-138 zeros*/
+#define NUM_CODE_LENGTH_CODES 19
+
+/*the base lengths represented by codes 257-285*/
+static const unsigned LENGTHBASE[29]
+ = {3, 4, 5, 6, 7, 8, 9, 10, 11, 13, 15, 17, 19, 23, 27, 31, 35, 43, 51, 59,
+ 67, 83, 99, 115, 131, 163, 195, 227, 258};
+
+/*the extra bits used by codes 257-285 (added to base length)*/
+static const unsigned LENGTHEXTRA[29]
+ = {0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 2, 2, 2, 2, 3, 3, 3, 3,
+ 4, 4, 4, 4, 5, 5, 5, 5, 0};
+
+/*the base backwards distances (the bits of distance codes appear after length codes and use their own huffman tree)*/
+static const unsigned DISTANCEBASE[30]
+ = {1, 2, 3, 4, 5, 7, 9, 13, 17, 25, 33, 49, 65, 97, 129, 193, 257, 385, 513,
+ 769, 1025, 1537, 2049, 3073, 4097, 6145, 8193, 12289, 16385, 24577};
+
+/*the extra bits of backwards distances (added to base)*/
+static const unsigned DISTANCEEXTRA[30]
+ = {0, 0, 0, 0, 1, 1, 2, 2, 3, 3, 4, 4, 5, 5, 6, 6, 7, 7, 8,
+ 8, 9, 9, 10, 10, 11, 11, 12, 12, 13, 13};
+
+/*the order in which "code length alphabet code lengths" are stored, out of this
+the huffman tree of the dynamic huffman tree lengths is generated*/
+static const unsigned CLCL_ORDER[NUM_CODE_LENGTH_CODES]
+ = {16, 17, 18, 0, 8, 7, 9, 6, 10, 5, 11, 4, 12, 3, 13, 2, 14, 1, 15};
+
+/* ////////////////////////////////////////////////////////////////////////// */
+
+/*
+Huffman tree struct, containing multiple representations of the tree
+*/
+typedef struct HuffmanTree
+{
+ uivector tree2d;
+ uivector tree1d;
+ uivector lengths; /*the lengths of the codes of the 1d-tree*/
+ unsigned maxbitlen; /*maximum number of bits a single code can get*/
+ unsigned numcodes; /*number of symbols in the alphabet = number of codes*/
+} HuffmanTree;
+
+/*function used for debug purposes to draw the tree in ascii art with C++*/
+/*#include <iostream>
+static void HuffmanTree_draw(HuffmanTree* tree)
+{
+ std::cout << "tree. length: " << tree->numcodes << " maxbitlen: " << tree->maxbitlen << std::endl;
+ for(size_t i = 0; i < tree->tree1d.size; i++)
+ {
+ if(tree->lengths.data[i])
+ std::cout << i << " " << tree->tree1d.data[i] << " " << tree->lengths.data[i] << std::endl;
+ }
+ std::cout << std::endl;
+}*/
+
+static void HuffmanTree_init(HuffmanTree* tree)
+{
+ uivector_init(&tree->tree2d);
+ uivector_init(&tree->tree1d);
+ uivector_init(&tree->lengths);
+}
+
+static void HuffmanTree_cleanup(HuffmanTree* tree)
+{
+ uivector_cleanup(&tree->tree2d);
+ uivector_cleanup(&tree->tree1d);
+ uivector_cleanup(&tree->lengths);
+}
+
+/*the tree representation used by the decoder. return value is error*/
+static unsigned HuffmanTree_make2DTree(HuffmanTree* tree)
+{
+ unsigned nodefilled = 0; /*up to which node it is filled*/
+ unsigned treepos = 0; /*position in the tree (1 of the numcodes columns)*/
+ unsigned n, i;
+
+ if(!uivector_resize(&tree->tree2d, tree->numcodes * 2)) return 9901; /*alloc fail*/
+
+ /*
+ convert tree1d[] to tree2d[][]. In the 2D array, a value of 32767 means
+ uninited, a value >= numcodes is an address to another bit, a value < numcodes
+ is a code. The 2 rows are the 2 possible bit values (0 or 1), there are as
+ many columns as codes - 1.
+ A good huffmann tree has N * 2 - 1 nodes, of which N - 1 are internal nodes.
+ Here, the internal nodes are stored (what their 0 and 1 option point to).
+ There is only memory for such good tree currently, if there are more nodes
+ (due to too long length codes), error 55 will happen
+ */
+ for(n = 0; n < tree->numcodes * 2; n++)
+ {
+ tree->tree2d.data[n] = 32767; /*32767 here means the tree2d isn't filled there yet*/
+ }
+
+ for(n = 0; n < tree->numcodes; n++) /*the codes*/
+ {
+ for(i = 0; i < tree->lengths.data[n]; i++) /*the bits for this code*/
+ {
+ unsigned char bit = (unsigned char)((tree->tree1d.data[n] >> (tree->lengths.data[n] - i - 1)) & 1);
+ if(treepos > tree->numcodes - 2) return 55; /*error 55: oversubscribed; see description in header*/
+ if(tree->tree2d.data[2 * treepos + bit] == 32767) /*not yet filled in*/
+ {
+ if(i + 1 == tree->lengths.data[n]) /*last bit*/
+ {
+ tree->tree2d.data[2 * treepos + bit] = n; /*put the current code in it*/
+ treepos = 0;
+ }
+ else
+ {
+ /*put address of the next step in here, first that address has to be found of course
+ (it's just nodefilled + 1)...*/
+ nodefilled++;
+ /*addresses encoded with numcodes added to it*/
+ tree->tree2d.data[2 * treepos + bit] = nodefilled + tree->numcodes;
+ treepos = nodefilled;
+ }
+ }
+ else treepos = tree->tree2d.data[2 * treepos + bit] - tree->numcodes;
+ }
+ }
+
+ for(n = 0; n < tree->numcodes * 2; n++)
+ {
+ if(tree->tree2d.data[n] == 32767) tree->tree2d.data[n] = 0; /*remove possible remaining 32767's*/
+ }
+
+ return 0;
+}
+
+/*
+Second step for the ...makeFromLengths and ...makeFromFrequencies functions.
+numcodes, lengths and maxbitlen must already be filled in correctly. return
+value is error.
+*/
+static unsigned HuffmanTree_makeFromLengths2(HuffmanTree* tree)
+{
+ uivector blcount;
+ uivector nextcode;
+ unsigned bits, n, error = 0;
+
+ uivector_init(&blcount);
+ uivector_init(&nextcode);
+ if(!uivector_resize(&tree->tree1d, tree->numcodes)
+ || !uivector_resizev(&blcount, tree->maxbitlen + 1, 0)
+ || !uivector_resizev(&nextcode, tree->maxbitlen + 1, 0))
+ error = 9902; /*alloc fail*/
+
+ if(!error)
+ {
+ /*step 1: count number of instances of each code length*/
+ for(bits = 0; bits < tree->numcodes; bits++) blcount.data[tree->lengths.data[bits]]++;
+ /*step 2: generate the nextcode values*/
+ for(bits = 1; bits <= tree->maxbitlen; bits++)
+ {
+ nextcode.data[bits] = (nextcode.data[bits - 1] + blcount.data[bits - 1]) << 1;
+ }
+ /*step 3: generate all the codes*/
+ for(n = 0; n < tree->numcodes; n++)
+ {
+ if(tree->lengths.data[n] != 0) tree->tree1d.data[n] = nextcode.data[tree->lengths.data[n]]++;
+ }
+ }
+
+ uivector_cleanup(&blcount);
+ uivector_cleanup(&nextcode);
+
+ if(!error) return HuffmanTree_make2DTree(tree);
+ else return error;
+}
+
+/*
+given the code lengths (as stored in the PNG file), generate the tree as defined
+by Deflate. maxbitlen is the maximum bits that a code in the tree can have.
+return value is error.
+*/
+static unsigned HuffmanTree_makeFromLengths(HuffmanTree* tree, const unsigned* bitlen,
+ size_t numcodes, unsigned maxbitlen)
+{
+ unsigned i;
+ if(!uivector_resize(&tree->lengths, numcodes)) return 9903; /*alloc fail*/
+ for(i = 0; i < numcodes; i++) tree->lengths.data[i] = bitlen[i];
+ tree->numcodes = (unsigned)numcodes; /*number of symbols*/
+ tree->maxbitlen = maxbitlen;
+ return HuffmanTree_makeFromLengths2(tree);
+}
+
+#ifdef LODEPNG_COMPILE_ENCODER
+
+/*
+A coin, this is the terminology used for the package-merge algorithm and the
+coin collector's problem. This is used to generate the huffman tree.
+A coin can be multiple coins (when they're merged)
+*/
+typedef struct Coin
+{
+ uivector symbols;
+ float weight; /*the sum of all weights in this coin*/
+} Coin;
+
+static void Coin_init(Coin* c)
+{
+ uivector_init(&c->symbols);
+}
+
+/*argument c is void* so that this dtor can be given as function pointer to the vector resize function*/
+static void Coin_cleanup(void* c)
+{
+ uivector_cleanup(&((Coin*)c)->symbols);
+}
+
+static void Coin_copy(Coin* c1, const Coin* c2)
+{
+ c1->weight = c2->weight;
+ uivector_copy(&c1->symbols, &c2->symbols);
+}
+
+static void addCoins(Coin* c1, const Coin* c2)
+{
+ size_t i;
+ for(i = 0; i < c2->symbols.size; i++) uivector_push_back(&c1->symbols, c2->symbols.data[i]);
+ c1->weight += c2->weight;
+}
+
+/*
+Coin_sort: This uses a simple combsort to sort the data. This function is not critical for
+overall encoding speed and the data amount isn't that large.
+*/
+static void Coin_sort(Coin* data, size_t amount)
+{
+ size_t gap = amount;
+ unsigned char swapped = 0;
+ while((gap > 1) || swapped)
+ {
+ size_t i;
+ gap = (gap * 10) / 13; /*shrink factor 1.3*/
+ if(gap == 9 || gap == 10) gap = 11; /*combsort11*/
+ if(gap < 1) gap = 1;
+ swapped = 0;
+ for(i = 0; i < amount - gap; i++)
+ {
+ size_t j = i + gap;
+ if(data[j].weight < data[i].weight)
+ {
+ float temp = data[j].weight; data[j].weight = data[i].weight; data[i].weight = temp;
+ uivector_swap(&data[i].symbols, &data[j].symbols);
+ swapped = 1;
+ }
+ }
+ }
+}
+
+static unsigned HuffmanTree_fillInCoins(vector* coins, const unsigned* frequencies, unsigned numcodes, size_t sum)
+{
+ unsigned i;
+ for(i = 0; i < numcodes; i++)
+ {
+ Coin* coin;
+ if(frequencies[i] == 0) continue; /*it's important to exclude symbols that aren't present*/
+ if(!vector_resize(coins, coins->size + 1))
+ {
+ vector_cleanup(coins);
+ return 9904; /*alloc fail*/
+ }
+ coin = (Coin*)(vector_get(coins, coins->size - 1));
+ Coin_init(coin);
+ coin->weight = frequencies[i] / (float)sum;
+ uivector_push_back(&coin->symbols, i);
+ }
+ if(coins->size) Coin_sort((Coin*)coins->data, coins->size);
+ return 0;
+}
+
+/*Create the Huffman tree given the symbol frequencies*/
+static unsigned HuffmanTree_makeFromFrequencies(HuffmanTree* tree, const unsigned* frequencies,
+ size_t numcodes, unsigned maxbitlen)
+{
+ unsigned i, j;
+ size_t sum = 0, numpresent = 0;
+ unsigned error = 0;
+
+ vector prev_row; /*type Coin, the previous row of coins*/
+ vector coins; /*type Coin, the coins of the currently calculated row*/
+
+ tree->maxbitlen = maxbitlen;
+
+ for(i = 0; i < numcodes; i++)
+ {
+ if(frequencies[i] > 0)
+ {
+ numpresent++;
+ sum += frequencies[i];
+ }
+ }
+
+ if(numcodes == 0) return 80; /*error: a tree of 0 symbols is not supposed to be made*/
+ tree->numcodes = (unsigned)numcodes; /*number of symbols*/
+ uivector_resize(&tree->lengths, 0);
+ if(!uivector_resizev(&tree->lengths, tree->numcodes, 0)) return 9905; /*alloc fail*/
+
+ /*there are no symbols at all, in that case add one symbol of value 0 to the tree (see RFC 1951 section 3.2.7) */
+ if(numpresent == 0)
+ {
+ tree->lengths.data[0] = 1;
+ return HuffmanTree_makeFromLengths2(tree);
+ }
+ /*the package merge algorithm gives wrong results if there's only one symbol
+ (theoretically 0 bits would then suffice, but we need a proper symbol for zlib)*/
+ else if(numpresent == 1)
+ {
+ for(i = 0; i < numcodes; i++) if(frequencies[i]) tree->lengths.data[i] = 1;
+ return HuffmanTree_makeFromLengths2(tree);
+ }
+
+ vector_init(&coins, sizeof(Coin));
+ vector_init(&prev_row, sizeof(Coin));
+
+ /*Package-Merge algorithm represented by coin collector's problem
+ For every symbol, maxbitlen coins will be created*/
+
+ /*first row, lowest denominator*/
+ error = HuffmanTree_fillInCoins(&coins, frequencies, tree->numcodes, sum);
+ if(!error)
+ {
+ for(j = 1; j <= maxbitlen && !error; j++) /*each of the remaining rows*/
+ {
+ vector_swap(&coins, &prev_row); /*swap instead of copying*/
+ if(!vector_resized(&coins, 0, Coin_cleanup)) ERROR_BREAK(9906 /*alloc fail*/);
+ for(i = 0; i + 1 < prev_row.size; i += 2)
+ {
+ if(!vector_resize(&coins, coins.size + 1)) ERROR_BREAK(9907 /*alloc fail*/);
+ Coin_init((Coin*)vector_get(&coins, coins.size - 1));
+ Coin_copy((Coin*)vector_get(&coins, coins.size - 1), (Coin*)vector_get(&prev_row, i));
+ /*merge the coins into packages*/
+ addCoins((Coin*)vector_get(&coins, coins.size - 1), (Coin*)vector_get(&prev_row, i + 1));
+ }
+ if(j < maxbitlen)
+ {
+ error = HuffmanTree_fillInCoins(&coins, frequencies, tree->numcodes, sum);
+ }
+ }
+ }
+
+ if(!error)
+ {
+ /*keep the coins with lowest weight, so that they add up to the amount of symbols - 1*/
+ vector_resized(&coins, numpresent - 1, Coin_cleanup);
+
+ /*calculate the lenghts of each symbol, as the amount of times a coin of each symbol is used*/
+ for(i = 0; i < coins.size; i++)
+ {
+ Coin* coin = (Coin*)vector_get(&coins, i);
+ for(j = 0; j < coin->symbols.size; j++) tree->lengths.data[coin->symbols.data[j]]++;
+ }
+
+ error = HuffmanTree_makeFromLengths2(tree);
+ }
+
+ vector_cleanupd(&coins, Coin_cleanup);
+ vector_cleanupd(&prev_row, Coin_cleanup);
+
+ return error;
+}
+
+static unsigned HuffmanTree_getCode(const HuffmanTree* tree, unsigned index)
+{
+ return tree->tree1d.data[index];
+}
+
+static unsigned HuffmanTree_getLength(const HuffmanTree* tree, unsigned index)
+{
+ return tree->lengths.data[index];
+}
+#endif /*LODEPNG_COMPILE_ENCODER*/
+
+/*get the literal and length code tree of a deflated block with fixed tree, as per the deflate specification*/
+static unsigned generateFixedLitLenTree(HuffmanTree* tree)
+{
+ unsigned i, error = 0;
+ uivector bitlen;
+ uivector_init(&bitlen);
+ if(!uivector_resize(&bitlen, NUM_DEFLATE_CODE_SYMBOLS)) error = 9909; /*alloc fail*/
+
+ if(!error)
+ {
+ /*288 possible codes: 0-255=literals, 256=endcode, 257-285=lengthcodes, 286-287=unused*/
+ for(i = 0; i <= 143; i++) bitlen.data[i] = 8;
+ for(i = 144; i <= 255; i++) bitlen.data[i] = 9;
+ for(i = 256; i <= 279; i++) bitlen.data[i] = 7;
+ for(i = 280; i <= 287; i++) bitlen.data[i] = 8;
+
+ error = HuffmanTree_makeFromLengths(tree, bitlen.data, NUM_DEFLATE_CODE_SYMBOLS, 15);
+ }
+
+ uivector_cleanup(&bitlen);
+ return error;
+}
+
+/*get the distance code tree of a deflated block with fixed tree, as specified in the deflate specification*/
+static unsigned generateFixedDistanceTree(HuffmanTree* tree)
+{
+ unsigned i, error = 0;
+ uivector bitlen;
+ uivector_init(&bitlen);
+ if(!uivector_resize(&bitlen, NUM_DISTANCE_SYMBOLS)) error = 9910; /*alloc fail*/
+
+ /*there are 32 distance codes, but 30-31 are unused*/
+ if(!error)
+ {
+ for(i = 0; i < NUM_DISTANCE_SYMBOLS; i++) bitlen.data[i] = 5;
+ error = HuffmanTree_makeFromLengths(tree, bitlen.data, NUM_DISTANCE_SYMBOLS, 15);
+ }
+ uivector_cleanup(&bitlen);
+ return error;
+}
+
+#ifdef LODEPNG_COMPILE_DECODER
+
+/*
+returns the code, or (unsigned)(-1) if error happened
+inbitlength is the length of the complete buffer, in bits (so its byte length times 8)
+*/
+static unsigned huffmanDecodeSymbol(const unsigned char* in, size_t* bp,
+ const HuffmanTree* codetree, size_t inbitlength)
+{
+ unsigned treepos = 0, ct;
+ for(;;)
+ {
+ if(*bp > inbitlength) return (unsigned)(-1); /*error: end of input memory reached without endcode*/
+
+ /*
+ decode the symbol from the tree. The "readBitFromStream" code is inlined in
+ the expression below because this is the biggest bottleneck while decoding
+ */
+ ct = codetree->tree2d.data[(treepos << 1) + READBIT(*bp, in)];
+ (*bp)++;
+ if(ct < codetree->numcodes) return ct; /*the symbol is decoded, return it*/
+ else treepos = ct - codetree->numcodes; /*symbol not yet decoded, instead move tree position*/
+
+ if(treepos >= codetree->numcodes) return (unsigned)(-1); /*error: it appeared outside the codetree*/
+ }
+}
+#endif /*LODEPNG_COMPILE_DECODER*/
+
+#ifdef LODEPNG_COMPILE_DECODER
+
+/* ////////////////////////////////////////////////////////////////////////// */
+/* / Inflator (Decompressor) / */
+/* ////////////////////////////////////////////////////////////////////////// */
+
+/*get the tree of a deflated block with fixed tree, as specified in the deflate specification*/
+static void getTreeInflateFixed(HuffmanTree* tree_ll, HuffmanTree* tree_d)
+{
+ /*error checking not done, this is fixed stuff, it works, it doesn't depend on the image*/
+ /*TODO: out of memory errors could still happen...*/
+ generateFixedLitLenTree(tree_ll);
+ generateFixedDistanceTree(tree_d);
+}
+
+/*get the tree of a deflated block with dynamic tree, the tree itself is also Huffman compressed with a known tree*/
+static unsigned getTreeInflateDynamic(HuffmanTree* tree_ll, HuffmanTree* tree_d,
+ const unsigned char* in, size_t* bp, size_t inlength)
+{
+ /*make sure that length values that aren't filled in will be 0, or a wrong tree will be generated*/
+ unsigned error = 0;
+ unsigned n, HLIT, HDIST, HCLEN, i;
+ size_t inbitlength = inlength * 8;
+
+ /*see comments in deflateDynamic for explanation of the context and these variables, it is analogous*/
+ uivector bitlen_ll; /*lit,len code lengths*/
+ uivector bitlen_d; /*dist code lengths*/
+ /*code length code lengths ("clcl"), the bit lengths of the huffman tree used to compress bitlen_ll and bitlen_d*/
+ uivector bitlen_cl;
+ HuffmanTree tree_cl; /*the code tree for code length codes (the huffman tree for compressed huffman trees)*/
+
+ if((*bp) >> 3 >= inlength - 2) return 49; /*the bit pointer is or will go past the memory*/
+
+ /*number of literal/length codes + 257. Unlike the spec, the value 257 is added to it here already*/
+ HLIT = readBitsFromStream(bp, in, 5) + 257;
+ /*number of distance codes. Unlike the spec, the value 1 is added to it here already*/
+ HDIST = readBitsFromStream(bp, in, 5) + 1;
+ /*number of code length codes. Unlike the spec, the value 4 is added to it here already*/
+ HCLEN = readBitsFromStream(bp, in, 4) + 4;
+
+ HuffmanTree_init(&tree_cl);
+ uivector_init(&bitlen_ll);
+ uivector_init(&bitlen_d);
+ uivector_init(&bitlen_cl);
+
+ while(!error)
+ {
+ /*read the code length codes out of 3 * (amount of code length codes) bits*/
+
+ if(!uivector_resize(&bitlen_cl, NUM_CODE_LENGTH_CODES)) ERROR_BREAK(9911);
+
+ for(i = 0; i < NUM_CODE_LENGTH_CODES; i++)
+ {
+ if(i < HCLEN) bitlen_cl.data[CLCL_ORDER[i]] = readBitsFromStream(bp, in, 3);
+ else bitlen_cl.data[CLCL_ORDER[i]] = 0; /*if not, it must stay 0*/
+ }
+
+ error = HuffmanTree_makeFromLengths(&tree_cl, bitlen_cl.data, bitlen_cl.size, 7);
+ if(error) break;
+
+ /*now we can use this tree to read the lengths for the tree that this function will return*/
+ uivector_resizev(&bitlen_ll, NUM_DEFLATE_CODE_SYMBOLS, 0);
+ uivector_resizev(&bitlen_d, NUM_DISTANCE_SYMBOLS, 0);
+ i = 0;
+ if(!bitlen_ll.data || !bitlen_d.data) ERROR_BREAK(9912); /*alloc fail*/
+
+ /*i is the current symbol we're reading in the part that contains the code lengths of lit/len and dist codes*/
+ while(i < HLIT + HDIST)
+ {
+ unsigned code = huffmanDecodeSymbol(in, bp, &tree_cl, inbitlength);
+ if(code <= 15) /*a length code*/
+ {
+ if(i < HLIT) bitlen_ll.data[i] = code;
+ else bitlen_d.data[i - HLIT] = code;
+ i++;
+ }
+ else if(code == 16) /*repeat previous*/
+ {
+ unsigned replength = 3; /*read in the 2 bits that indicate repeat length (3-6)*/
+ unsigned value; /*set value to the previous code*/
+
+ if((*bp) >> 3 >= inlength) ERROR_BREAK(50); /*error, bit pointer jumps past memory*/
+
+ replength += readBitsFromStream(bp, in, 2);
+
+ if((i - 1) < HLIT) value = bitlen_ll.data[i - 1];
+ else value = bitlen_d.data[i - HLIT - 1];
+ /*repeat this value in the next lengths*/
+ for(n = 0; n < replength; n++)
+ {
+ if(i >= HLIT + HDIST) ERROR_BREAK(13); /*error: i is larger than the amount of codes*/
+ if(i < HLIT) bitlen_ll.data[i] = value;
+ else bitlen_d.data[i - HLIT] = value;
+ i++;
+ }
+ }
+ else if(code == 17) /*repeat "0" 3-10 times*/
+ {
+ unsigned replength = 3; /*read in the bits that indicate repeat length*/
+ if((*bp) >> 3 >= inlength) ERROR_BREAK(50); /*error, bit pointer jumps past memory*/
+
+ replength += readBitsFromStream(bp, in, 3);
+
+ /*repeat this value in the next lengths*/
+ for(n = 0; n < replength; n++)
+ {
+ if(i >= HLIT + HDIST) ERROR_BREAK(14); /*error: i is larger than the amount of codes*/
+
+ if(i < HLIT) bitlen_ll.data[i] = 0;
+ else bitlen_d.data[i - HLIT] = 0;
+ i++;
+ }
+ }
+ else if(code == 18) /*repeat "0" 11-138 times*/
+ {
+ unsigned replength = 11; /*read in the bits that indicate repeat length*/
+ if((*bp) >> 3 >= inlength) ERROR_BREAK(50); /*error, bit pointer jumps past memory*/
+
+ replength += readBitsFromStream(bp, in, 7);
+
+ /*repeat this value in the next lengths*/
+ for(n = 0; n < replength; n++)
+ {
+ if(i >= HLIT + HDIST) ERROR_BREAK(15); /*error: i is larger than the amount of codes*/
+
+ if(i < HLIT) bitlen_ll.data[i] = 0;
+ else bitlen_d.data[i - HLIT] = 0;
+ i++;
+ }
+ }
+ else /*if(code == (unsigned)(-1))*/ /*huffmanDecodeSymbol returns (unsigned)(-1) in case of error*/
+ {
+ if(code == (unsigned)(-1))
+ {
+ /*return error code 10 or 11 depending on the situation that happened in huffmanDecodeSymbol
+ (10=no endcode, 11=wrong jump outside of tree)*/
+ error = (*bp) > inlength * 8 ? 10 : 11;
+ }
+ else error = 16; /*unexisting code, this can never happen*/
+ break;
+ }
+ }
+ if(error) break;
+
+ if(bitlen_ll.data[256] == 0) ERROR_BREAK(64); /*the length of the end code 256 must be larger than 0*/
+
+ /*now we've finally got HLIT and HDIST, so generate the code trees, and the function is done*/
+ error = HuffmanTree_makeFromLengths(tree_ll, &bitlen_ll.data[0], bitlen_ll.size, 15);
+ if(error) break;
+ error = HuffmanTree_makeFromLengths(tree_d, &bitlen_d.data[0], bitlen_d.size, 15);
+
+ break; /*end of error-while*/
+ }
+
+ uivector_cleanup(&bitlen_cl);
+ uivector_cleanup(&bitlen_ll);
+ uivector_cleanup(&bitlen_d);
+ HuffmanTree_cleanup(&tree_cl);
+
+ return error;
+}
+
+/*inflate a block with dynamic of fixed Huffman tree*/
+static unsigned inflateHuffmanBlock(ucvector* out, const unsigned char* in, size_t* bp,
+ size_t* pos, size_t inlength, unsigned btype)
+{
+ unsigned error = 0;
+ HuffmanTree tree_ll; /*the huffman tree for literal and length codes*/
+ HuffmanTree tree_d; /*the huffman tree for distance codes*/
+ size_t inbitlength = inlength * 8;
+
+ HuffmanTree_init(&tree_ll);
+ HuffmanTree_init(&tree_d);
+
+ if(btype == 1) getTreeInflateFixed(&tree_ll, &tree_d);
+ else if(btype == 2)
+ {
+ error = getTreeInflateDynamic(&tree_ll, &tree_d, in, bp, inlength);
+ }
+
+ for(;;) /*decode all symbols until end reached*/
+ {
+ /*code_ll is literal, length or end code*/
+ unsigned code_ll = huffmanDecodeSymbol(in, bp, &tree_ll, inbitlength);
+ if(code_ll <= 255) /*literal symbol*/
+ {
+ if((*pos) >= out->size)
+ {
+ /*reserve more room at once*/
+ if(!ucvector_resize(out, ((*pos) + 1) * 2)) ERROR_BREAK(9913 /*alloc fail*/);
+ }
+ out->data[(*pos)] = (unsigned char)(code_ll);
+ (*pos)++;
+ }
+ else if(code_ll >= FIRST_LENGTH_CODE_INDEX && code_ll <= LAST_LENGTH_CODE_INDEX) /*length code*/
+ {
+ unsigned code_d, distance;
+ unsigned numextrabits_l, numextrabits_d; /*extra bits for length and distance*/
+ size_t start, forward, backward, length;
+
+ /*part 1: get length base*/
+ length = LENGTHBASE[code_ll - FIRST_LENGTH_CODE_INDEX];
+
+ /*part 2: get extra bits and add the value of that to length*/
+ numextrabits_l = LENGTHEXTRA[code_ll - FIRST_LENGTH_CODE_INDEX];
+ if(((*bp) >> 3) >= inlength) ERROR_BREAK(51); /*error, bit pointer will jump past memory*/
+ length += readBitsFromStream(bp, in, numextrabits_l);
+
+ /*part 3: get distance code*/
+ code_d = huffmanDecodeSymbol(in, bp, &tree_d, inbitlength);
+ if(code_d > 29)
+ {
+ if(code_ll == (unsigned)(-1)) /*huffmanDecodeSymbol returns (unsigned)(-1) in case of error*/
+ {
+ /*return error code 10 or 11 depending on the situation that happened in huffmanDecodeSymbol
+ (10=no endcode, 11=wrong jump outside of tree)*/
+ error = (*bp) > inlength * 8 ? 10 : 11;
+ }
+ else error = 18; /*error: invalid distance code (30-31 are never used)*/
+ break;
+ }
+ distance = DISTANCEBASE[code_d];
+
+ /*part 4: get extra bits from distance*/
+ numextrabits_d = DISTANCEEXTRA[code_d];
+ if(((*bp) >> 3) >= inlength) ERROR_BREAK(51); /*error, bit pointer will jump past memory*/
+
+ distance += readBitsFromStream(bp, in, numextrabits_d);
+
+ /*part 5: fill in all the out[n] values based on the length and dist*/
+ start = (*pos);
+ backward = start - distance;
+ if((*pos) + length >= out->size)
+ {
+ /*reserve more room at once*/
+ if(!ucvector_resize(out, ((*pos) + length) * 2)) ERROR_BREAK(9914 /*alloc fail*/);
+ }
+
+ for(forward = 0; forward < length; forward++)
+ {
+ out->data[(*pos)] = out->data[backward];
+ (*pos)++;
+ backward++;
+ if(backward >= start) backward = start - distance;
+ }
+ }
+ else if(code_ll == 256)
+ {
+ break; /*end code, break the loop*/
+ }
+ else /*if(code == (unsigned)(-1))*/ /*huffmanDecodeSymbol returns (unsigned)(-1) in case of error*/
+ {
+ /*return error code 10 or 11 depending on the situation that happened in huffmanDecodeSymbol
+ (10=no endcode, 11=wrong jump outside of tree)*/
+ error = (*bp) > inlength * 8 ? 10 : 11;
+ break;
+ }
+ }
+
+ HuffmanTree_cleanup(&tree_ll);
+ HuffmanTree_cleanup(&tree_d);
+
+ return error;
+}
+
+static unsigned inflateNoCompression(ucvector* out, const unsigned char* in, size_t* bp, size_t* pos, size_t inlength)
+{
+ /*go to first boundary of byte*/
+ size_t p;
+ unsigned LEN, NLEN, n, error = 0;
+ while(((*bp) & 0x7) != 0) (*bp)++;
+ p = (*bp) / 8; /*byte position*/
+
+ /*read LEN (2 bytes) and NLEN (2 bytes)*/
+ if(p >= inlength - 4) return 52; /*error, bit pointer will jump past memory*/
+ LEN = in[p] + 256 * in[p + 1]; p += 2;
+ NLEN = in[p] + 256 * in[p + 1]; p += 2;
+
+ /*check if 16-bit NLEN is really the one's complement of LEN*/
+ if(LEN + NLEN != 65535) return 21; /*error: NLEN is not one's complement of LEN*/
+
+ if((*pos) + LEN >= out->size)
+ {
+ if(!ucvector_resize(out, (*pos) + LEN)) return 9915; /*alloc fail*/
+ }
+
+ /*read the literal data: LEN bytes are now stored in the out buffer*/
+ if(p + LEN > inlength) return 23; /*error: reading outside of in buffer*/
+ for(n = 0; n < LEN; n++) out->data[(*pos)++] = in[p++];
+
+ (*bp) = p * 8;
+
+ return error;
+}
+
+/*inflate the deflated data (cfr. deflate spec); return value is the error*/
+static unsigned LodePNG_inflate(ucvector* out, const unsigned char* in, size_t insize, size_t inpos)
+{
+ /*bit pointer in the "in" data, current byte is bp >> 3, current bit is bp & 0x7 (from lsb to msb of the byte)*/
+ size_t bp = 0;
+ unsigned BFINAL = 0;
+ size_t pos = 0; /*byte position in the out buffer*/
+
+ unsigned error = 0;
+
+ while(!BFINAL)
+ {
+ unsigned BTYPE;
+ if(bp + 2 >= insize * 8) return 52; /*error, bit pointer will jump past memory*/
+ BFINAL = readBitFromStream(&bp, &in[inpos]);
+ BTYPE = 1 * readBitFromStream(&bp, &in[inpos]);
+ BTYPE += 2 * readBitFromStream(&bp, &in[inpos]);
+
+ if(BTYPE == 3) return 20; /*error: invalid BTYPE*/
+ else if(BTYPE == 0) error = inflateNoCompression(out, &in[inpos], &bp, &pos, insize); /*no compression*/
+ else error = inflateHuffmanBlock(out, &in[inpos], &bp, &pos, insize, BTYPE); /*compression, BTYPE 01 or 10*/
+
+ if(error) return error;
+ }
+
+ /*Only now we know the true size of out, resize it to that*/
+ if(!ucvector_resize(out, pos)) error = 9916; /*alloc fail*/
+
+ return error;
+}
+
+#endif /*LODEPNG_COMPILE_DECODER*/
+
+#ifdef LODEPNG_COMPILE_ENCODER
+
+/* ////////////////////////////////////////////////////////////////////////// */
+/* / Deflator (Compressor) / */
+/* ////////////////////////////////////////////////////////////////////////// */
+
+static const size_t MAX_SUPPORTED_DEFLATE_LENGTH = 258;
+
+/*bitlen is the size in bits of the code*/
+static void addHuffmanSymbol(size_t* bp, ucvector* compressed, unsigned code, unsigned bitlen)
+{
+ addBitsToStreamReversed(bp, compressed, code, bitlen);
+}
+
+/*search the index in the array, that has the largest value smaller than or equal to the given value,
+given array must be sorted (if no value is smaller, it returns the size of the given array)*/
+static size_t searchCodeIndex(const unsigned* array, size_t array_size, size_t value)
+{
+ /*linear search implementation*/
+ /*for(size_t i = 1; i < array_size; i++) if(array[i] > value) return i - 1;
+ return array_size - 1;*/
+
+ /*binary search implementation (not that much faster) (precondition: array_size > 0)*/
+ size_t left = 1;
+ size_t right = array_size - 1;
+ while(left <= right)
+ {
+ size_t mid = (left + right) / 2;
+ if(array[mid] <= value) left = mid + 1; /*the value to find is more to the right*/
+ else if(array[mid - 1] > value) right = mid - 1; /*the value to find is more to the left*/
+ else return mid - 1;
+ }
+ return array_size - 1;
+}
+
+static void addLengthDistance(uivector* values, size_t length, size_t distance)
+{
+ /*values in encoded vector are those used by deflate:
+ 0-255: literal bytes
+ 256: end
+ 257-285: length/distance pair (length code, followed by extra length bits, distance code, extra distance bits)
+ 286-287: invalid*/
+
+ unsigned length_code = (unsigned)searchCodeIndex(LENGTHBASE, 29, length);
+ unsigned extra_length = (unsigned)(length - LENGTHBASE[length_code]);
+ unsigned dist_code = (unsigned)searchCodeIndex(DISTANCEBASE, 30, distance);
+ unsigned extra_distance = (unsigned)(distance - DISTANCEBASE[dist_code]);
+
+ uivector_push_back(values, length_code + FIRST_LENGTH_CODE_INDEX);
+ uivector_push_back(values, extra_length);
+ uivector_push_back(values, dist_code);
+ uivector_push_back(values, extra_distance);
+}
+
+#if 0
+/*the "brute force" version of the encodeLZ7 algorithm, not used anymore, kept here for reference*/
+static unsigned encodeLZ77_brute(uivector* out, const unsigned char* in, size_t insize, unsigned windowSize)
+{
+ size_t pos;
+ for(pos = 0; pos < insize; pos++)
+ {
+ size_t length = 0, offset = 0; /*the length and offset found for the current position*/
+ size_t max_offset = pos < windowSize ? pos : windowSize; /*how far back to test*/
+ size_t current_offset;
+
+ /**search for the longest string, backwards through all possible distances (=offsets)**/
+ for(current_offset = 1; current_offset < max_offset; current_offset++)
+ {
+ size_t backpos = pos - current_offset;
+ if(in[backpos] == in[pos])
+ {
+ /*test the next characters*/
+ size_t current_length = 1;
+ size_t backtest = backpos + 1;
+ size_t foretest = pos + 1;
+ /*maximum supporte length by deflate is max length*/
+ while(foretest < insize && in[backtest] == in[foretest] && current_length < MAX_SUPPORTED_DEFLATE_LENGTH)
+ {
+ if(backpos >= pos)
+ {
+ /*continue as if we work on the decoded bytes after pos by jumping back before pos*/
+ backpos -= current_offset;
+ }
+ current_length++;
+ backtest++;
+ foretest++;
+ }
+ if(current_length > length)
+ {
+ length = current_length; /*the longest length*/
+ offset = current_offset; /*the offset that is related to this longest length*/
+ /*you can jump out of this for loop once a length of max length is found (gives significant speed gain)*/
+ if(current_length == MAX_SUPPORTED_DEFLATE_LENGTH) break;
+ }
+ }
+ }
+
+ /**encode it as length/distance pair or literal value**/
+ if(length < 3) /*only lengths of 3 or higher are supported as length/distance pair*/
+ {
+ uivector_push_back(out, in[pos]);
+ }
+ else
+ {
+ addLengthDistance(out, length, offset);
+ pos += (length - 1);
+ }
+ } /*end of the loop through each character of input*/
+ return 0;
+}
+#endif
+
+static const unsigned HASH_NUM_VALUES = 2048;
+static const unsigned HASH_NUM_CHARACTERS = 3;
+static const unsigned HASH_SHIFT = 2;
+/*
+The HASH_NUM_CHARACTERS value is used to make encoding faster by using longer
+sequences to generate a hash value from the stream bytes. Setting it to 3
+gives exactly the same compression as the brute force method, since deflate's
+run length encoding starts with lengths of 3. Setting it to higher values,
+like 6, can make the encoding faster (not always though!), but will cause the
+encoding to miss any length between 3 and this value, so that the compression
+may be worse (but this can vary too depending on the image, sometimes it is
+even a bit better instead).
+The HASH_NUM_VALUES is the amount of unique possible hash values that
+combinations of bytes can give, the higher it is the more memory is needed, but
+if it's too low the advantage of hashing is gone.
+*/
+
+static unsigned getHash(const unsigned char* data, size_t size, size_t pos, size_t num)
+{
+ unsigned result = 0;
+ size_t amount, i;
+ if(pos >= size) return 0;
+ amount = num;
+ if(pos + amount >= size) amount = size - pos;
+ for(i = 0; i < amount; i++) result ^= (data[pos + i] << (i * HASH_SHIFT));
+ return result % HASH_NUM_VALUES;
+}
+
+static unsigned countInitialZeros(const unsigned char* data, size_t size, size_t pos)
+{
+ size_t max_count = MAX_SUPPORTED_DEFLATE_LENGTH;
+ size_t i;
+ if(max_count > size - pos) max_count = size - pos;
+ for(i = 0; i < max_count; i++)
+ {
+ if(data[pos + i] != 0)
+ return i;
+ }
+ return max_count;
+}
+
+/*push a value to the vector in a circular way. This is to do as if we're extending
+the vector's size forever, but instead the size is limited to maxsize and it wraps
+around, to avoid too large memory size. The pos pointer gets updated to the current
+end (unless updatepos is false, in that case pos is only used to know the current
+value). returns 1 on success, 0 if fail*/
+static unsigned push_circular(uivector* v, unsigned* pos, unsigned value, size_t maxsize, unsigned updatepos)
+{
+ if(v->size < maxsize)
+ {
+ if(!uivector_push_back(v, value)) return 0;
+ if(updatepos) (*pos)++;
+ }
+ else
+ {
+ if(updatepos)
+ {
+ (*pos)++;
+ if((*pos) > maxsize) (*pos) = 1;
+ }
+ v->data[(*pos) - 1] = value;
+ }
+ return 1;
+}
+
+/*Enable to use lazy instead of greedy matghing. It looks one byte further
+to see if that one gives a longer distance. This gives slightly better compression, at the cost
+of a speed loss.*/
+#define LAZY_MATCHING
+
+/*
+LZ77-encode the data. Return value is error code. The input are raw bytes, the output
+is in the form of unsigned integers with codes representing for example literal bytes, or
+length/distance pairs.
+It uses a hash table technique to let it encode faster. When doing LZ77 encoding, a
+sliding window (of windowSize) is used, and all past bytes in that window can be used as
+the "dictionary". A brute force search through all possible distances would be slow, and
+this hash technique is one out of several ways to speed this up.
+*/
+static unsigned encodeLZ77(uivector* out, const unsigned char* in, size_t insize, unsigned windowSize)
+{
+ /**generate hash table**/
+ /*
+ The hash table is 2-dimensional. For every possible hash value, it contains a list of positions
+ in the data where this hash occured.
+ tablepos1 and tablepos2 remember the last used start and end index in the hash table for each hash value.
+ */
+ vector table; /*HASH_NUM_VALUES uivectors; this is what would be an std::vector<std::vector<unsigned> > in C++*/
+ uivector tablepos1, tablepos2;
+ /*hash 0 indicates a possible common case of a long sequence of zeros, store and use the amount here for a speedup*/
+ uivector initialZerosTable;
+ unsigned pos, i, error = 0;
+ unsigned hash_num_characters = HASH_NUM_CHARACTERS;
+
+ vector_init(&table, sizeof(uivector));
+ if(!vector_resize(&table, HASH_NUM_VALUES)) return 9917; /*alloc fail*/
+ for(i = 0; i < HASH_NUM_VALUES; i++)
+ {
+ uivector* v = (uivector*)vector_get(&table, i);
+ uivector_init(v);
+ }
+
+ /*remember start and end positions in the tables to search in*/
+ uivector_init(&tablepos1);
+ uivector_init(&tablepos2);
+ uivector_init(&initialZerosTable);
+
+ if(!uivector_resizev(&tablepos1, HASH_NUM_VALUES, 0)) error = 9918; /*alloc fail*/
+ if(!uivector_resizev(&tablepos2, HASH_NUM_VALUES, 0)) error = 9919; /*alloc fail*/
+
+ if(!error)
+ {
+ unsigned offset, max_offset; /*the offset represents the distance in LZ77 terminology*/
+ unsigned length, tablepos;
+#ifdef LAZY_MATCHING
+ unsigned lazy = 0;
+ unsigned lazylength, lazyoffset;
+#endif /*LAZY_MATCHING*/
+ unsigned hash, initialZeros = 0;
+ unsigned backpos, current_offset, t1, t2, t11, current_length;
+ const unsigned char *lastptr, *foreptr, *backptr;
+ uivector* v; /*vector from the hash table we're currently working on*/
+ unsigned hashWindow = windowSize;
+ unsigned numones = 0;
+
+ for(pos = 0; pos < insize; pos++)
+ {
+ length = 0, offset = 0; /*the length and offset found for the current position*/
+ max_offset = pos < windowSize ? pos : windowSize; /*how far back to test*/
+
+ /*search for the longest string. First find out where in the table to start
+ (the first value that is in the range from "pos - max_offset" to "pos")*/
+ hash = getHash(in, insize, pos, hash_num_characters);
+ v = (uivector*)vector_get(&table, hash);
+ if(!push_circular(v, &tablepos2.data[hash], pos, hashWindow, 1)) ERROR_BREAK(9920 /*alloc fail*/);
+
+ if(hash == 0)
+ {
+ initialZeros = countInitialZeros(in, insize, pos);
+ if(!push_circular(&initialZerosTable, &tablepos2.data[hash], initialZeros, hashWindow, 0))
+ ERROR_BREAK(9920 /*alloc fail*/);
+ }
+
+ while(v->data[tablepos1.data[hash]] < pos - max_offset)
+ {
+ /*it now points to the first value in the table for which the index is
+ larger than or equal to pos - max_offset*/
+ tablepos1.data[hash]++;
+ if(tablepos1.data[hash] >= hashWindow) tablepos1.data[hash] = 0;
+ }
+
+ t1 = tablepos1.data[hash];
+ t2 = tablepos2.data[hash] - 1;
+ if(tablepos2.data[hash] == 0) t2 = hashWindow - 1;
+
+ lastptr = &in[insize < pos + MAX_SUPPORTED_DEFLATE_LENGTH ? insize : pos + MAX_SUPPORTED_DEFLATE_LENGTH];
+
+ t11 = t1 == 0 ? hashWindow - 1 : t1 - 1;
+ for(tablepos = t2 == 0 ? hashWindow - 1 : t2 - 1;
+ tablepos != t2 && tablepos != t11 && tablepos < v->size;
+ tablepos = tablepos == 0 ? hashWindow - 1 : tablepos - 1)
+ {
+ backpos = v->data[tablepos];
+ current_offset = pos - backpos;
+ /*test the next characters*/
+ foreptr = &in[pos];
+ backptr = &in[backpos];
+
+ if(hash == 0)
+ {
+ unsigned skip = initialZerosTable.data[tablepos];
+ if(skip > initialZeros) skip = initialZeros;
+ if(skip > insize - pos) skip = insize - pos;
+ backptr += skip;
+ foreptr += skip;
+ }
+ while(foreptr != lastptr && *backptr == *foreptr) /*maximum supported length by deflate is max length*/
+ {
+ ++backptr;
+ ++foreptr;
+ }
+ current_length = (unsigned)(foreptr - &in[pos]);
+ if(current_length > length)
+ {
+ length = current_length; /*the longest length*/
+ offset = current_offset; /*the offset that is related to this longest length*/
+ /*you can jump out of this for loop once a length of max length is found (gives significant speed gain)*/
+ if(current_length == MAX_SUPPORTED_DEFLATE_LENGTH) break;
+ }
+ }
+
+#ifdef LAZY_MATCHING
+ if(!lazy && length >= 3 && length < MAX_SUPPORTED_DEFLATE_LENGTH)
+ {
+ lazylength = length;
+ lazyoffset = offset;
+ lazy = 1;
+ continue;
+ }
+ if(lazy)
+ {
+ if(pos == 0) ERROR_BREAK(81);
+ lazy = 0;
+ if(length > lazylength + 1)
+ {
+ /*push the previous character as literal*/
+ if(!uivector_push_back(out, in[pos - 1])) ERROR_BREAK(9921 /*alloc fail*/);
+ }
+ else
+ {
+ length = lazylength;
+ offset = lazyoffset;
+ pos--;
+ }
+ }
+#endif /*LAZY_MATCHING*/
+
+ /**encode it as length/distance pair or literal value**/
+ if(length < 3) /*only lengths of 3 or higher are supported as length/distance pair*/
+ {
+ if(!uivector_push_back(out, in[pos])) ERROR_BREAK(9921 /*alloc fail*/);
+ }
+ else
+ {
+ unsigned j, local_hash;
+ addLengthDistance(out, length, offset);
+ for(j = 0; j < length - 1; j++)
+ {
+ unsigned* t2p; /*pointer to current tablepos2 element*/
+ pos++;
+ local_hash = getHash(in, insize, pos, hash_num_characters);
+ t2p = &tablepos2.data[local_hash];
+ v = (uivector*)vector_get(&table, local_hash);
+ if(!push_circular(v, t2p, pos, hashWindow, 1)) ERROR_BREAK(9920 /*alloc fail*/);
+
+ if(local_hash == 0)
+ {
+ initialZeros = countInitialZeros(in, insize, pos);
+ if(!push_circular(&initialZerosTable, t2p, initialZeros, hashWindow, 0))
+ ERROR_BREAK(9922 /*alloc fail*/);
+ }
+ if(local_hash == 1 && hash_num_characters == 3)
+ {
+ /*
+ If many hash values are getting grouped together in hash value 1, 4, 16, 20, ...,
+ it indicates there are many near-zero values. This is not zero enough to benefit from a speed
+ increase from the initialZerosTable, and makes it very slow. For that case only, switch to
+ hash_num_characters = 6. Value 6 is experimentally found to be fastest. For this particular type
+ of file, the compression isn't even worse, despite the fact that lengths < 6 are now no longer
+ found, and that by changing hash_num_characters not all previously found hash values are still valid.
+ Almost all images compress fast enough and smaller with hash_num_characters = 3, except sine plasma
+ images. Those benefit a lot from this heuristic.
+ */
+ if(numones > 8192 && numones > pos / 16) hash_num_characters = 6;
+ else numones++;
+ }
+ }
+ }
+ } /*end of the loop through each character of input*/
+ } /*end of "if(!error)"*/
+
+ /*cleanup*/
+ for(i = 0; i < table.size; i++)
+ {
+ uivector* v = (uivector*)vector_get(&table, i);
+ uivector_cleanup(v);
+ }
+ vector_cleanup(&table);
+ uivector_cleanup(&tablepos1);
+ uivector_cleanup(&tablepos2);
+ uivector_cleanup(&initialZerosTable);
+ return error;
+}
+
+/* /////////////////////////////////////////////////////////////////////////// */
+
+static unsigned deflateNoCompression(ucvector* out, const unsigned char* data, size_t datasize)
+{
+ /*non compressed deflate block data: 1 bit BFINAL,2 bits BTYPE,(5 bits): it jumps to start of next byte,
+ 2 bytes LEN, 2 bytes NLEN, LEN bytes literal DATA*/
+
+ size_t i, j, numdeflateblocks = datasize / 65536 + 1;
+ unsigned datapos = 0;
+ for(i = 0; i < numdeflateblocks; i++)
+ {
+ unsigned BFINAL, BTYPE, LEN, NLEN;
+ unsigned char firstbyte;
+
+ BFINAL = (i == numdeflateblocks - 1);
+ BTYPE = 0;
+
+ firstbyte = (unsigned char)(BFINAL + ((BTYPE & 1) << 1) + ((BTYPE & 2) << 1));
+ ucvector_push_back(out, firstbyte);
+
+ LEN = 65535;
+ if(datasize - datapos < 65535) LEN = (unsigned)datasize - datapos;
+ NLEN = 65535 - LEN;
+
+ ucvector_push_back(out, (unsigned char)(LEN % 256));
+ ucvector_push_back(out, (unsigned char)(LEN / 256));
+ ucvector_push_back(out, (unsigned char)(NLEN % 256));
+ ucvector_push_back(out, (unsigned char)(NLEN / 256));
+
+ /*Decompressed data*/
+ for(j = 0; j < 65535 && datapos < datasize; j++)
+ {
+ ucvector_push_back(out, data[datapos++]);
+ }
+ }
+
+ return 0;
+}
+
+/*
+write the lz77-encoded data, which has lit, len and dist codes, to compressed stream using huffman trees.
+tree_ll: the tree for lit and len codes.
+tree_d: the tree for distance codes.
+*/
+static void writeLZ77data(size_t* bp, ucvector* out, const uivector* lz77_encoded,
+ const HuffmanTree* tree_ll, const HuffmanTree* tree_d)
+{
+ size_t i = 0;
+ for(i = 0; i < lz77_encoded->size; i++)
+ {
+ unsigned val = lz77_encoded->data[i];
+ addHuffmanSymbol(bp, out, HuffmanTree_getCode(tree_ll, val), HuffmanTree_getLength(tree_ll, val));
+ if(val > 256) /*for a length code, 3 more things have to be added*/
+ {
+ unsigned length_index = val - FIRST_LENGTH_CODE_INDEX;
+ unsigned n_length_extra_bits = LENGTHEXTRA[length_index];
+ unsigned length_extra_bits = lz77_encoded->data[++i];
+
+ unsigned distance_code = lz77_encoded->data[++i];
+
+ unsigned distance_index = distance_code;
+ unsigned n_distance_extra_bits = DISTANCEEXTRA[distance_index];
+ unsigned distance_extra_bits = lz77_encoded->data[++i];
+
+ addBitsToStream(bp, out, length_extra_bits, n_length_extra_bits);
+ addHuffmanSymbol(bp, out, HuffmanTree_getCode(tree_d, distance_code),
+ HuffmanTree_getLength(tree_d, distance_code));
+ addBitsToStream(bp, out, distance_extra_bits, n_distance_extra_bits);
+ }
+ }
+}
+
+/*Deflate for a block of type "dynamic", that is, with freely, optimally, created huffman trees*/
+static unsigned deflateDynamic(ucvector* out, const unsigned char* data, size_t datasize,
+ const LodePNG_CompressSettings* settings)
+{
+ unsigned error = 0;
+
+ /*
+ A block is compressed as follows: The PNG data is lz77 encoded, resulting in
+ literal bytes and length/distance pairs. This is then huffman compressed with
+ two huffman trees. One huffman tree is used for the lit and len values ("ll"),
+ another huffman tree is used for the dist values ("d"). These two trees are
+ stored using their code lengths, and to compress even more these code lengths
+ are also run-length encoded and huffman compressed. This gives a huffman tree
+ of code lengths "cl". The code lenghts used to describe this third tree are
+ the code length code lengths ("clcl").
+ */
+
+ /*The lz77 encoded data, represented with integers since there will also be length and distance codes in it*/
+ uivector lz77_encoded;
+ HuffmanTree tree_ll; /*tree for lit,len values*/
+ HuffmanTree tree_d; /*tree for distance codes*/
+ HuffmanTree tree_cl; /*tree for encoding the code lengths representing tree_ll and tree_d*/
+ uivector frequencies_ll; /*frequency of lit,len codes*/
+ uivector frequencies_d; /*frequency of dist codes*/
+ uivector frequencies_cl; /*frequency of code length codes*/
+ uivector bitlen_lld; /*lit,len,dist code lenghts (int bits), literally (without repeat codes).*/
+ uivector bitlen_lld_e; /*bitlen_lld encoded with repeat codes (this is a rudemtary run length compression)*/
+ /*bitlen_cl is the code length code lengths ("clcl"). The bit lengths of codes to represent tree_cl
+ (these are written as is in the file, it would be crazy to compress these using yet another huffman
+ tree that needs to be represented by yet another set of code lengths)*/
+ uivector bitlen_cl;
+
+ /*
+ Due to the huffman compression of huffman tree representations ("two levels"), there are some anologies:
+ bitlen_lld is to tree_cl what data is to tree_ll and tree_d.
+ bitlen_lld_e is to bitlen_lld what lz77_encoded is to data.
+ bitlen_cl is to bitlen_lld_e what bitlen_lld is to lz77_encoded.
+ */
+
+ unsigned BFINAL = 1; /*make only one block... the first and final one*/
+ size_t numcodes_ll, numcodes_d, i;
+ size_t bp = 0; /*the bit pointer*/
+ unsigned HLIT, HDIST, HCLEN;
+
+ uivector_init(&lz77_encoded);
+ HuffmanTree_init(&tree_ll);
+ HuffmanTree_init(&tree_d);
+ HuffmanTree_init(&tree_cl);
+ uivector_init(&frequencies_ll);
+ uivector_init(&frequencies_d);
+ uivector_init(&frequencies_cl);
+ uivector_init(&bitlen_lld);
+ uivector_init(&bitlen_lld_e);
+ uivector_init(&bitlen_cl);
+
+ /*This while loop is never loops due to a break at the end, it is here to
+ allow breaking out of it to the cleanup phase on error conditions.*/
+ while(!error)
+ {
+ if(settings->useLZ77)
+ {
+ error = encodeLZ77(&lz77_encoded, data, datasize, settings->windowSize); /*LZ77 encoded*/
+ if(error) break;
+ }
+ else
+ {
+ if(!uivector_resize(&lz77_encoded, datasize)) ERROR_BREAK(9923 /*alloc fail*/);
+ for(i = 0; i < datasize; i++) lz77_encoded.data[i] = data[i]; /*no LZ77, but still will be Huffman compressed*/
+ }
+
+ if(!uivector_resizev(&frequencies_ll, 286, 0)) ERROR_BREAK(9924 /*alloc fail*/);
+ if(!uivector_resizev(&frequencies_d, 30, 0)) ERROR_BREAK(9925 /*alloc fail*/);
+
+ /*Count the frequencies of lit, len and dist codes*/
+ for(i = 0; i < lz77_encoded.size; i++)
+ {
+ unsigned symbol = lz77_encoded.data[i];
+ frequencies_ll.data[symbol]++;
+ if(symbol > 256)
+ {
+ unsigned dist = lz77_encoded.data[i + 2];
+ frequencies_d.data[dist]++;
+ i += 3;
+ }
+ }
+ frequencies_ll.data[256] = 1; /*there will be exactly 1 end code, at the end of the block*/
+
+ /*Make both huffman trees, one for the lit and len codes, one for the dist codes*/
+ error = HuffmanTree_makeFromFrequencies(&tree_ll, frequencies_ll.data, frequencies_ll.size, 15);
+ if(error) break;
+ error = HuffmanTree_makeFromFrequencies(&tree_d, frequencies_d.data, frequencies_d.size, 15);
+ if(error) break;
+
+ numcodes_ll = tree_ll.numcodes; if(numcodes_ll > 286) numcodes_ll = 286;
+ numcodes_d = tree_d.numcodes; if(numcodes_d > 30) numcodes_d = 30;
+ /*store the code lengths of both generated trees in bitlen_lld*/
+ for(i = 0; i < numcodes_ll; i++) uivector_push_back(&bitlen_lld, HuffmanTree_getLength(&tree_ll, (unsigned)i));
+ for(i = 0; i < numcodes_d; i++) uivector_push_back(&bitlen_lld, HuffmanTree_getLength(&tree_d, (unsigned)i));
+
+ /*run-length compress bitlen_ldd into bitlen_lld_e by using repeat codes 16 (copy length 3-6 times),
+ 17 (3-10 zeroes), 18 (11-138 zeroes)*/
+ for(i = 0; i < (unsigned)bitlen_lld.size; i++)
+ {
+ unsigned j = 0; /*amount of repititions*/
+ while(i + j + 1 < (unsigned)bitlen_lld.size && bitlen_lld.data[i + j + 1] == bitlen_lld.data[i]) j++;
+
+ if(bitlen_lld.data[i] == 0 && j >= 2) /*repeat code for zeroes*/
+ {
+ j++; /*include the first zero*/
+ if(j <= 10) /*repeat code 17 supports max 10 zeroes*/
+ {
+ uivector_push_back(&bitlen_lld_e, 17);
+ uivector_push_back(&bitlen_lld_e, j - 3);
+ }
+ else /*repeat code 18 supports max 138 zeroes*/
+ {
+ if(j > 138) j = 138;
+ uivector_push_back(&bitlen_lld_e, 18);
+ uivector_push_back(&bitlen_lld_e, j - 11);
+ }
+ i += (j - 1);
+ }
+ else if(j >= 3) /*repeat code for value other than zero*/
+ {
+ size_t k;
+ unsigned num = j / 6, rest = j % 6;
+ uivector_push_back(&bitlen_lld_e, bitlen_lld.data[i]);
+ for(k = 0; k < num; k++)
+ {
+ uivector_push_back(&bitlen_lld_e, 16);
+ uivector_push_back(&bitlen_lld_e, 6 - 3);
+ }
+ if(rest >= 3)
+ {
+ uivector_push_back(&bitlen_lld_e, 16);
+ uivector_push_back(&bitlen_lld_e, rest - 3);
+ }
+ else j -= rest;
+ i += j;
+ }
+ else /*too short to benefit from repeat code*/
+ {
+ uivector_push_back(&bitlen_lld_e, bitlen_lld.data[i]);
+ }
+ }
+
+ /*generate tree_cl, the huffmantree of huffmantrees*/
+
+ if(!uivector_resizev(&frequencies_cl, NUM_CODE_LENGTH_CODES, 0)) ERROR_BREAK(9926 /*alloc fail*/);
+ for(i = 0; i < bitlen_lld_e.size; i++)
+ {
+ frequencies_cl.data[bitlen_lld_e.data[i]]++;
+ /*after a repeat code come the bits that specify the number of repetitions,
+ those don't need to be in the frequencies_cl calculation*/
+ if(bitlen_lld_e.data[i] >= 16) i++;
+ }
+
+ error = HuffmanTree_makeFromFrequencies(&tree_cl, frequencies_cl.data, frequencies_cl.size, 7);
+ if(error) break;
+
+ if(!uivector_resize(&bitlen_cl, NUM_CODE_LENGTH_CODES)) ERROR_BREAK(9927 /*alloc fail*/);
+ for(i = 0; i < NUM_CODE_LENGTH_CODES; i++)
+ {
+ /*lenghts of code length tree is in the order as specified by deflate*/
+ bitlen_cl.data[i] = HuffmanTree_getLength(&tree_cl, CLCL_ORDER[i]);
+ }
+ while(bitlen_cl.data[bitlen_cl.size - 1] == 0 && bitlen_cl.size > 4)
+ {
+ /*remove zeros at the end, but minimum size must be 4*/
+ if(!uivector_resize(&bitlen_cl, bitlen_cl.size - 1)) ERROR_BREAK(9928 /*alloc fail*/);
+ }
+ if(error) break;
+
+ /*
+ Write everything into the output
+
+ After the BFINAL and BTYPE, the dynamic block consists out of the following:
+ - 5 bits HLIT, 5 bits HDIST, 4 bits HCLEN
+ - (HCLEN+4)*3 bits code lengths of code length alphabet
+ - HLIT + 257 code lenghts of lit/length alphabet (encoded using the code length
+ alphabet, + possible repetition codes 16, 17, 18)
+ - HDIST + 1 code lengths of distance alphabet (encoded using the code length
+ alphabet, + possible repetition codes 16, 17, 18)
+ - compressed data
+ - 256 (end code)
+ */
+
+ /*Write block type*/
+ addBitToStream(&bp, out, BFINAL);
+ addBitToStream(&bp, out, 0); /*first bit of BTYPE "dynamic"*/
+ addBitToStream(&bp, out, 1); /*second bit of BTYPE "dynamic"*/
+
+ /*write the HLIT, HDIST and HCLEN values*/
+ HLIT = (unsigned)(numcodes_ll - 257);
+ HDIST = (unsigned)(numcodes_d - 1);
+ HCLEN = (unsigned)bitlen_cl.size - 4;
+ addBitsToStream(&bp, out, HLIT, 5);
+ addBitsToStream(&bp, out, HDIST, 5);
+ addBitsToStream(&bp, out, HCLEN, 4);
+
+ /*write the code lenghts of the code length alphabet*/
+ for(i = 0; i < HCLEN + 4; i++) addBitsToStream(&bp, out, bitlen_cl.data[i], 3);
+
+ /*write the lenghts of the lit/len AND the dist alphabet*/
+ for(i = 0; i < bitlen_lld_e.size; i++)
+ {
+ addHuffmanSymbol(&bp, out, HuffmanTree_getCode(&tree_cl, bitlen_lld_e.data[i]),
+ HuffmanTree_getLength(&tree_cl, bitlen_lld_e.data[i]));
+ /*extra bits of repeat codes*/
+ if(bitlen_lld_e.data[i] == 16) addBitsToStream(&bp, out, bitlen_lld_e.data[++i], 2);
+ else if(bitlen_lld_e.data[i] == 17) addBitsToStream(&bp, out, bitlen_lld_e.data[++i], 3);
+ else if(bitlen_lld_e.data[i] == 18) addBitsToStream(&bp, out, bitlen_lld_e.data[++i], 7);
+ }
+
+ /*write the compressed data symbols*/
+ writeLZ77data(&bp, out, &lz77_encoded, &tree_ll, &tree_d);
+ /*error: the length of the end code 256 must be larger than 0*/
+ if(HuffmanTree_getLength(&tree_ll, 256) == 0) ERROR_BREAK(64);
+
+ /*write the end code*/
+ addHuffmanSymbol(&bp, out, HuffmanTree_getCode(&tree_ll, 256), HuffmanTree_getLength(&tree_ll, 256));
+
+ break; /*end of error-while*/
+ }
+
+ /*cleanup*/
+ uivector_cleanup(&lz77_encoded);
+ HuffmanTree_cleanup(&tree_ll);
+ HuffmanTree_cleanup(&tree_d);
+ HuffmanTree_cleanup(&tree_cl);
+ uivector_cleanup(&frequencies_ll);
+ uivector_cleanup(&frequencies_d);
+ uivector_cleanup(&frequencies_cl);
+ uivector_cleanup(&bitlen_lld_e);
+ uivector_cleanup(&bitlen_lld);
+ uivector_cleanup(&bitlen_cl);
+
+ return error;
+}
+
+static unsigned deflateFixed(ucvector* out, const unsigned char* data,
+ size_t datasize, const LodePNG_CompressSettings* settings)
+{
+ HuffmanTree tree_ll; /*tree for literal values and length codes*/
+ HuffmanTree tree_d; /*tree for distance codes*/
+
+ unsigned BFINAL = 1; /*make only one block... the first and final one*/
+ unsigned error = 0;
+ size_t i, bp = 0; /*the bit pointer*/
+
+ HuffmanTree_init(&tree_ll);
+ HuffmanTree_init(&tree_d);
+
+ generateFixedLitLenTree(&tree_ll);
+ generateFixedDistanceTree(&tree_d);
+
+ addBitToStream(&bp, out, BFINAL);
+ addBitToStream(&bp, out, 1); /*first bit of BTYPE*/
+ addBitToStream(&bp, out, 0); /*second bit of BTYPE*/
+
+ if(settings->useLZ77) /*LZ77 encoded*/
+ {
+ uivector lz77_encoded;
+ uivector_init(&lz77_encoded);
+ error = encodeLZ77(&lz77_encoded, data, datasize, settings->windowSize);
+ if(!error) writeLZ77data(&bp, out, &lz77_encoded, &tree_ll, &tree_d);
+ uivector_cleanup(&lz77_encoded);
+ }
+ else /*no LZ77, but still will be Huffman compressed*/
+ {
+ for(i = 0; i < datasize; i++)
+ {
+ addHuffmanSymbol(&bp, out, HuffmanTree_getCode(&tree_ll, data[i]), HuffmanTree_getLength(&tree_ll, data[i]));
+ }
+ }
+ /*add END code*/
+ if(!error) addHuffmanSymbol(&bp, out, HuffmanTree_getCode(&tree_ll, 256), HuffmanTree_getLength(&tree_ll, 256));
+
+ /*cleanup*/
+ HuffmanTree_cleanup(&tree_ll);
+ HuffmanTree_cleanup(&tree_d);
+
+ return error;
+}
+
+static unsigned LodePNG_deflate(ucvector* out, const unsigned char* data, size_t datasize,
+ const LodePNG_CompressSettings* settings)
+{
+ unsigned error = 0;
+ if(settings->btype == 0) error = deflateNoCompression(out, data, datasize);
+ else if(settings->btype == 1) error = deflateFixed(out, data, datasize, settings);
+ else if(settings->btype == 2) error = deflateDynamic(out, data, datasize, settings);
+ else error = 61;
+ return error;
+}
+
+#endif /*LODEPNG_COMPILE_DECODER*/
+
+/* ////////////////////////////////////////////////////////////////////////// */
+/* / Adler32 */
+/* ////////////////////////////////////////////////////////////////////////// */
+
+static unsigned update_adler32(unsigned adler, const unsigned char* data, unsigned len)
+{
+ unsigned s1 = adler & 0xffff;
+ unsigned s2 = (adler >> 16) & 0xffff;
+
+ while(len > 0)
+ {
+ /*at least 5550 sums can be done before the sums overflow, saving a lot of module divisions*/
+ unsigned amount = len > 5550 ? 5550 : len;
+ len -= amount;
+ while(amount > 0)
+ {
+ s1 = (s1 + *data++);
+ s2 = (s2 + s1);
+ amount--;
+ }
+ s1 %= 65521;
+ s2 %= 65521;
+ }
+
+ return (s2 << 16) | s1;
+}
+
+/*Return the adler32 of the bytes data[0..len-1]*/
+static unsigned adler32(const unsigned char* data, unsigned len)
+{
+ return update_adler32(1L, data, len);
+}
+
+/* ////////////////////////////////////////////////////////////////////////// */
+/* / Zlib / */
+/* ////////////////////////////////////////////////////////////////////////// */
+
+#ifdef LODEPNG_COMPILE_DECODER
+
+unsigned LodePNG_zlib_decompress(unsigned char** out, size_t* outsize, const unsigned char* in,
+ size_t insize, const LodePNG_DecompressSettings* settings)
+{
+ unsigned error = 0;
+ unsigned CM, CINFO, FDICT;
+ ucvector outv;
+
+ if(insize < 2) return 53; /*error, size of zlib data too small*/
+ /*read information from zlib header*/
+ if((in[0] * 256 + in[1]) % 31 != 0)
+ {
+ /*error: 256 * in[0] + in[1] must be a multiple of 31, the FCHECK value is supposed to be made that way*/
+ return 24;
+ }
+
+ CM = in[0] & 15;
+ CINFO = (in[0] >> 4) & 15;
+ /*FCHECK = in[1] & 31;*/ /*FCHECK is already tested above*/
+ FDICT = (in[1] >> 5) & 1;
+ /*FLEVEL = (in[1] >> 6) & 3;*/ /*FLEVEL is not used here*/
+
+ if(CM != 8 || CINFO > 7)
+ {
+ /*error: only compression method 8: inflate with sliding window of 32k is supported by the PNG spec*/
+ return 25;
+ }
+ if(FDICT != 0)
+ {
+ /*error: the specification of PNG says about the zlib stream:
+ "The additional flags shall not specify a preset dictionary."*/
+ return 26;
+ }
+
+ /*ucvector-controlled version of the output buffer, for dynamic array*/
+ ucvector_init_buffer(&outv, *out, *outsize);
+ error = LodePNG_inflate(&outv, in, insize, 2);
+ *out = outv.data;
+ *outsize = outv.size;
+ if(error) return error;
+
+ if(!settings->ignoreAdler32)
+ {
+ unsigned ADLER32 = LodePNG_read32bitInt(&in[insize - 4]);
+ unsigned checksum = adler32(outv.data, (unsigned)outv.size);
+ if(checksum != ADLER32) return 58; /*error, adler checksum not correct, data must be corrupted*/
+ }
+
+ return 0; /*no error*/
+}
+
+#endif /*LODEPNG_COMPILE_DECODER*/
+
+#ifdef LODEPNG_COMPILE_ENCODER
+
+unsigned LodePNG_zlib_compress(unsigned char** out, size_t* outsize, const unsigned char* in,
+ size_t insize, const LodePNG_CompressSettings* settings)
+{
+ /*initially, *out must be NULL and outsize 0, if you just give some random *out
+ that's pointing to a non allocated buffer, this'll crash*/
+ ucvector deflatedata, outv;
+ size_t i;
+ unsigned error;
+
+ unsigned ADLER32;
+ /*zlib data: 1 byte CMF (CM+CINFO), 1 byte FLG, deflate data, 4 byte ADLER32 checksum of the Decompressed data*/
+ unsigned CMF = 120; /*0b01111000: CM 8, CINFO 7. With CINFO 7, any window size up to 32768 can be used.*/
+ unsigned FLEVEL = 0;
+ unsigned FDICT = 0;
+ unsigned CMFFLG = 256 * CMF + FDICT * 32 + FLEVEL * 64;
+ unsigned FCHECK = 31 - CMFFLG % 31;
+ CMFFLG += FCHECK;
+
+ /*ucvector-controlled version of the output buffer, for dynamic array*/
+ ucvector_init_buffer(&outv, *out, *outsize);
+
+ ucvector_push_back(&outv, (unsigned char)(CMFFLG / 256));
+ ucvector_push_back(&outv, (unsigned char)(CMFFLG % 256));
+
+ ucvector_init(&deflatedata);
+ error = LodePNG_deflate(&deflatedata, in, insize, settings);
+
+ if(!error)
+ {
+ ADLER32 = adler32(in, (unsigned)insize);
+ for(i = 0; i < deflatedata.size; i++) ucvector_push_back(&outv, deflatedata.data[i]);
+ ucvector_cleanup(&deflatedata);
+ LodePNG_add32bitInt(&outv, ADLER32);
+ }
+
+ *out = outv.data;
+ *outsize = outv.size;
+
+ return error;
+}
+
+#endif /*LODEPNG_COMPILE_ENCODER*/
+
+#else /*no LODEPNG_COMPILE_ZLIB*/
+
+/*
+Dummy functions used if LODEPNG_COMPILE_ZLIB isn't defined. You need to implement
+these yourself when disabling the LodePNG Zlib part, e.g. by calling another
+library from here.
+
+*out must be NULL and *outsize must be 0 initially, and after the function is done,
+*out must point to the decompressed data, *outsize must be the size of it, and must
+be the size of the useful data in bytes, not the alloc size.
+*/
+
+#ifdef LODEPNG_COMPILE_DECODER
+static unsigned LodePNG_zlib_decompress(unsigned char** out, size_t* outsize, const unsigned char* in,
+ size_t insize, const LodePNG_DecompressSettings* settings)
+{
+ return 0; //Placeholder to be implemented if LODEPNG_COMPILE_ZLIB is disabled.
+}
+#endif /*LODEPNG_COMPILE_DECODER*/
+#ifdef LODEPNG_COMPILE_ENCODER
+static unsigned LodePNG_zlib_compress(unsigned char** out, size_t* outsize, const unsigned char* in,
+ size_t insize, const LodePNG_CompressSettings* settings)
+{
+ return 0; //Placeholder to be implemented if LODEPNG_COMPILE_ZLIB is disabled.
+}
+#endif /*LODEPNG_COMPILE_ENCODER*/
+
+#endif /*LODEPNG_COMPILE_ZLIB*/
+
+/* ////////////////////////////////////////////////////////////////////////// */
+
+#ifdef LODEPNG_COMPILE_ENCODER
+
+/*this is a good tradeoff between speed and compression ratio*/
+#define DEFAULT_WINDOWSIZE 2048
+
+void LodePNG_CompressSettings_init(LodePNG_CompressSettings* settings)
+{
+ /*compress with dynamic huffman tree (not in the mathematical sense, just not the predefined one)*/
+ settings->btype = 2;
+ settings->useLZ77 = 1;
+ settings->windowSize = DEFAULT_WINDOWSIZE;
+}
+
+const LodePNG_CompressSettings LodePNG_defaultCompressSettings = {2, 1, DEFAULT_WINDOWSIZE};
+
+#endif /*LODEPNG_COMPILE_ENCODER*/
+
+#ifdef LODEPNG_COMPILE_DECODER
+
+void LodePNG_DecompressSettings_init(LodePNG_DecompressSettings* settings)
+{
+ settings->ignoreAdler32 = 0;
+}
+
+const LodePNG_DecompressSettings LodePNG_defaultDecompressSettings = {0};
+
+#endif /*LODEPNG_COMPILE_DECODER*/
+
+/* ////////////////////////////////////////////////////////////////////////// */
+/* ////////////////////////////////////////////////////////////////////////// */
+/* // End of Zlib related code. Begin of PNG related code. // */
+/* ////////////////////////////////////////////////////////////////////////// */
+/* ////////////////////////////////////////////////////////////////////////// */
+
+#ifdef LODEPNG_COMPILE_PNG
+
+/* ////////////////////////////////////////////////////////////////////////// */
+/* / CRC32 / */
+/* ////////////////////////////////////////////////////////////////////////// */
+
+static unsigned Crc32_crc_table_computed = 0;
+static unsigned Crc32_crc_table[256];
+
+/*Make the table for a fast CRC.*/
+static void Crc32_make_crc_table(void)
+{
+ unsigned c, k, n;
+ for(n = 0; n < 256; n++)
+ {
+ c = n;
+ for(k = 0; k < 8; k++)
+ {
+ if(c & 1) c = 0xedb88320L ^ (c >> 1);
+ else c = c >> 1;
+ }
+ Crc32_crc_table[n] = c;
+ }
+ Crc32_crc_table_computed = 1;
+}
+
+/*Update a running CRC with the bytes buf[0..len-1]--the CRC should be
+initialized to all 1's, and the transmitted value is the 1's complement of the
+final running CRC (see the crc() routine below).*/
+static unsigned Crc32_update_crc(const unsigned char* buf, unsigned crc, size_t len)
+{
+ unsigned c = crc;
+ size_t n;
+
+ if(!Crc32_crc_table_computed) Crc32_make_crc_table();
+ for(n = 0; n < len; n++)
+ {
+ c = Crc32_crc_table[(c ^ buf[n]) & 0xff] ^ (c >> 8);
+ }
+ return c;
+}
+
+/*Return the CRC of the bytes buf[0..len-1].*/
+static unsigned Crc32_crc(const unsigned char* buf, size_t len)
+{
+ return Crc32_update_crc(buf, 0xffffffffL, len) ^ 0xffffffffL;
+}
+
+/* ////////////////////////////////////////////////////////////////////////// */
+/* / Reading and writing single bits and bytes from/to stream for LodePNG / */
+/* ////////////////////////////////////////////////////////////////////////// */
+
+static unsigned char readBitFromReversedStream(size_t* bitpointer, const unsigned char* bitstream)
+{
+ unsigned char result = (unsigned char)((bitstream[(*bitpointer) >> 3] >> (7 - ((*bitpointer) & 0x7))) & 1);
+ (*bitpointer)++;
+ return result;
+}
+
+static unsigned readBitsFromReversedStream(size_t* bitpointer, const unsigned char* bitstream, size_t nbits)
+{
+ unsigned result = 0;
+ size_t i;
+ for(i = nbits - 1; i < nbits; i--)
+ {
+ result += (unsigned)readBitFromReversedStream(bitpointer, bitstream) << i;
+ }
+ return result;
+}
+
+#ifdef LODEPNG_COMPILE_DECODER
+static void setBitOfReversedStream0(size_t* bitpointer, unsigned char* bitstream, unsigned char bit)
+{
+ /*the current bit in bitstream must be 0 for this to work*/
+ if(bit)
+ {
+ /*earlier bit of huffman code is in a lesser significant bit of an earlier byte*/
+ bitstream[(*bitpointer) >> 3] |= (bit << (7 - ((*bitpointer) & 0x7)));
+ }
+ (*bitpointer)++;
+}
+#endif /*LODEPNG_COMPILE_DECODER*/
+
+static void setBitOfReversedStream(size_t* bitpointer, unsigned char* bitstream, unsigned char bit)
+{
+ /*the current bit in bitstream may be 0 or 1 for this to work*/
+ if(bit == 0) bitstream[(*bitpointer) >> 3] &= (unsigned char)(~(1 << (7 - ((*bitpointer) & 0x7))));
+ else bitstream[(*bitpointer) >> 3] |= (1 << (7 - ((*bitpointer) & 0x7)));
+ (*bitpointer)++;
+}
+
+/* ////////////////////////////////////////////////////////////////////////// */
+/* / PNG chunks / */
+/* ////////////////////////////////////////////////////////////////////////// */
+
+unsigned LodePNG_chunk_length(const unsigned char* chunk)
+{
+ return LodePNG_read32bitInt(&chunk[0]);
+}
+
+void LodePNG_chunk_type(char type[5], const unsigned char* chunk)
+{
+ unsigned i;
+ for(i = 0; i < 4; i++) type[i] = chunk[4 + i];
+ type[4] = 0; /*null termination char*/
+}
+
+unsigned char LodePNG_chunk_type_equals(const unsigned char* chunk, const char* type)
+{
+ if(strlen(type) != 4) return 0;
+ return (chunk[4] == type[0] && chunk[5] == type[1] && chunk[6] == type[2] && chunk[7] == type[3]);
+}
+
+unsigned char LodePNG_chunk_critical(const unsigned char* chunk)
+{
+ return((chunk[4] & 32) == 0);
+}
+
+unsigned char LodePNG_chunk_private(const unsigned char* chunk)
+{
+ return((chunk[6] & 32) != 0);
+}
+
+unsigned char LodePNG_chunk_safetocopy(const unsigned char* chunk)
+{
+ return((chunk[7] & 32) != 0);
+}
+
+unsigned char* LodePNG_chunk_data(unsigned char* chunk)
+{
+ return &chunk[8];
+}
+
+const unsigned char* LodePNG_chunk_data_const(const unsigned char* chunk)
+{
+ return &chunk[8];
+}
+
+unsigned LodePNG_chunk_check_crc(const unsigned char* chunk)
+{
+ unsigned length = LodePNG_chunk_length(chunk);
+ unsigned CRC = LodePNG_read32bitInt(&chunk[length + 8]);
+ /*the CRC is taken of the data and the 4 chunk type letters, not the length*/
+ unsigned checksum = Crc32_crc(&chunk[4], length + 4);
+ if(CRC != checksum) return 1;
+ else return 0;
+}
+
+void LodePNG_chunk_generate_crc(unsigned char* chunk)
+{
+ unsigned length = LodePNG_chunk_length(chunk);
+ unsigned CRC = Crc32_crc(&chunk[4], length + 4);
+ LodePNG_set32bitInt(chunk + 8 + length, CRC);
+}
+
+unsigned char* LodePNG_chunk_next(unsigned char* chunk)
+{
+ unsigned total_chunk_length = LodePNG_chunk_length(chunk) + 12;
+ return &chunk[total_chunk_length];
+}
+
+const unsigned char* LodePNG_chunk_next_const(const unsigned char* chunk)
+{
+ unsigned total_chunk_length = LodePNG_chunk_length(chunk) + 12;
+ return &chunk[total_chunk_length];
+}
+
+unsigned LodePNG_append_chunk(unsigned char** out, size_t* outlength, const unsigned char* chunk)
+{
+ unsigned i;
+ unsigned total_chunk_length = LodePNG_chunk_length(chunk) + 12;
+ unsigned char *chunk_start, *new_buffer;
+ size_t new_length = (*outlength) + total_chunk_length;
+ if(new_length < total_chunk_length || new_length < (*outlength)) return 77; /*integer overflow happened*/
+
+ new_buffer = (unsigned char*)realloc(*out, new_length);
+ if(!new_buffer) return 9929; /*alloc fail*/
+ (*out) = new_buffer;
+ (*outlength) = new_length;
+ chunk_start = &(*out)[new_length - total_chunk_length];
+
+ for(i = 0; i < total_chunk_length; i++) chunk_start[i] = chunk[i];
+
+ return 0;
+}
+
+unsigned LodePNG_create_chunk(unsigned char** out, size_t* outlength, unsigned length,
+ const char* type, const unsigned char* data)
+{
+ unsigned i;
+ unsigned char *chunk, *new_buffer;
+ size_t new_length = (*outlength) + length + 12;
+ if(new_length < length + 12 || new_length < (*outlength)) return 77; /*integer overflow happened*/
+ new_buffer = (unsigned char*)realloc(*out, new_length);
+ if(!new_buffer) return 9930; /*alloc fail*/
+ (*out) = new_buffer;
+ (*outlength) = new_length;
+ chunk = &(*out)[(*outlength) - length - 12];
+
+ /*1: length*/
+ LodePNG_set32bitInt(chunk, (unsigned)length);
+
+ /*2: chunk name (4 letters)*/
+ chunk[4] = type[0];
+ chunk[5] = type[1];
+ chunk[6] = type[2];
+ chunk[7] = type[3];
+
+ /*3: the data*/
+ for(i = 0; i < length; i++) chunk[8 + i] = data[i];
+
+ /*4: CRC (of the chunkname characters and the data)*/
+ LodePNG_chunk_generate_crc(chunk);
+
+ return 0;
+}
+
+/* ////////////////////////////////////////////////////////////////////////// */
+/* / Color types and such / */
+/* ////////////////////////////////////////////////////////////////////////// */
+
+/*return type is a LodePNG error code*/
+static unsigned checkColorValidity(unsigned colorType, unsigned bd) /*bd = bitDepth*/
+{
+ switch(colorType)
+ {
+ case 0: if(!(bd == 1 || bd == 2 || bd == 4 || bd == 8 || bd == 16)) return 37; break; /*grey*/
+ case 2: if(!( bd == 8 || bd == 16)) return 37; break; /*RGB*/
+ case 3: if(!(bd == 1 || bd == 2 || bd == 4 || bd == 8 )) return 37; break; /*palette*/
+ case 4: if(!( bd == 8 || bd == 16)) return 37; break; /*grey + alpha*/
+ case 6: if(!( bd == 8 || bd == 16)) return 37; break; /*RGBA*/
+ default: return 31;
+ }
+ return 0; /*allowed color type / bits combination*/
+}
+
+static unsigned getNumColorChannels(unsigned colorType)
+{
+ switch(colorType)
+ {
+ case 0: return 1; /*grey*/
+ case 2: return 3; /*RGB*/
+ case 3: return 1; /*palette*/
+ case 4: return 2; /*grey + alpha*/
+ case 6: return 4; /*RGBA*/
+ }
+ return 0; /*unexisting color type*/
+}
+
+static unsigned getBpp(unsigned colorType, unsigned bitDepth)
+{
+ /*bits per pixel is amount of channels * bits per channel*/
+ return getNumColorChannels(colorType) * bitDepth;
+}
+
+/* ////////////////////////////////////////////////////////////////////////// */
+
+void LodePNG_InfoColor_init(LodePNG_InfoColor* info)
+{
+ info->key_defined = 0;
+ info->key_r = info->key_g = info->key_b = 0;
+ info->colorType = 6;
+ info->bitDepth = 8;
+ info->palette = 0;
+ info->palettesize = 0;
+}
+
+void LodePNG_InfoColor_cleanup(LodePNG_InfoColor* info)
+{
+ LodePNG_InfoColor_clearPalette(info);
+}
+
+void LodePNG_InfoColor_clearPalette(LodePNG_InfoColor* info)
+{
+ if(info->palette) free(info->palette);
+ info->palettesize = 0;
+}
+
+unsigned LodePNG_InfoColor_addPalette(LodePNG_InfoColor* info,
+ unsigned char r, unsigned char g, unsigned char b, unsigned char a)
+{
+ unsigned char* data;
+ /*the same resize technique as C++ std::vectors is used, and here it's made so that for a palette with
+ the max of 256 colors, it'll have the exact alloc size*/
+ if(!(info->palettesize & (info->palettesize - 1))) /*if palettesize is 0 or a power of two*/
+ {
+ /*allocated data must be at least 4* palettesize (for 4 color bytes)*/
+ size_t alloc_size = info->palettesize == 0 ? 4 : info->palettesize * 4 * 2;
+ data = (unsigned char*)realloc(info->palette, alloc_size);
+ if(!data) return 9931; /*alloc fail*/
+ else info->palette = data;
+ }
+ info->palette[4 * info->palettesize + 0] = r;
+ info->palette[4 * info->palettesize + 1] = g;
+ info->palette[4 * info->palettesize + 2] = b;
+ info->palette[4 * info->palettesize + 3] = a;
+ info->palettesize++;
+ return 0;
+}
+
+unsigned LodePNG_InfoColor_getBpp(const LodePNG_InfoColor* info)
+{
+ /*calculate bits per pixel out of colorType and bitDepth*/
+ return getBpp(info->colorType, info->bitDepth);
+}
+
+unsigned LodePNG_InfoColor_getChannels(const LodePNG_InfoColor* info)
+{
+ return getNumColorChannels(info->colorType);
+}
+
+unsigned LodePNG_InfoColor_isGreyscaleType(const LodePNG_InfoColor* info)
+{
+ return info->colorType == 0 || info->colorType == 4;
+}
+
+unsigned LodePNG_InfoColor_isAlphaType(const LodePNG_InfoColor* info)
+{
+ return (info->colorType & 4) != 0;
+}
+
+unsigned LodePNG_InfoColor_isPaletteType(const LodePNG_InfoColor* info)
+{
+ return info->colorType == 3;
+}
+
+unsigned LodePNG_InfoColor_hasPaletteAlpha(const LodePNG_InfoColor* info)
+{
+ size_t i;
+ for(i = 0; i < info->palettesize; i++)
+ {
+ if(info->palette[i * 4 + 3] < 255) return 1;
+ }
+ return 0;
+}
+
+unsigned LodePNG_InfoColor_canHaveAlpha(const LodePNG_InfoColor* info)
+{
+ return info->key_defined
+ || LodePNG_InfoColor_isAlphaType(info)
+ || LodePNG_InfoColor_hasPaletteAlpha(info);
+}
+
+unsigned LodePNG_InfoColor_equal(const LodePNG_InfoColor* info1, const LodePNG_InfoColor* info2)
+{
+ return info1->colorType == info2->colorType
+ && info1->bitDepth == info2->bitDepth; /*palette and color key not compared*/
+}
+
+#ifdef LODEPNG_COMPILE_UNKNOWN_CHUNKS
+void LodePNG_UnknownChunks_init(LodePNG_UnknownChunks* chunks)
+{
+ unsigned i;
+ for(i = 0; i < 3; i++) chunks->data[i] = 0;
+ for(i = 0; i < 3; i++) chunks->datasize[i] = 0;
+}
+
+void LodePNG_UnknownChunks_cleanup(LodePNG_UnknownChunks* chunks)
+{
+ unsigned i;
+ for(i = 0; i < 3; i++) free(chunks->data[i]);
+}
+
+unsigned LodePNG_UnknownChunks_copy(LodePNG_UnknownChunks* dest, const LodePNG_UnknownChunks* src)
+{
+ unsigned i;
+
+ LodePNG_UnknownChunks_cleanup(dest);
+
+ for(i = 0; i < 3; i++)
+ {
+ size_t j;
+ dest->datasize[i] = src->datasize[i];
+ dest->data[i] = (unsigned char*)malloc(src->datasize[i]);
+ if(!dest->data[i] && dest->datasize[i]) return 9932; /*alloc fail*/
+ for(j = 0; j < src->datasize[i]; j++) dest->data[i][j] = src->data[i][j];
+ }
+
+ return 0;
+}
+#endif /*LODEPNG_COMPILE_UNKNOWN_CHUNKS*/
+
+#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS
+void LodePNG_Text_init(LodePNG_Text* text)
+{
+ text->num = 0;
+ text->keys = NULL;
+ text->strings = NULL;
+}
+
+void LodePNG_Text_cleanup(LodePNG_Text* text)
+{
+ LodePNG_Text_clear(text);
+}
+
+unsigned LodePNG_Text_copy(LodePNG_Text* dest, const LodePNG_Text* source)
+{
+ size_t i = 0;
+ dest->keys = 0;
+ dest->strings = 0;
+ dest->num = 0;
+ for(i = 0; i < source->num; i++)
+ {
+ unsigned error = LodePNG_Text_add(dest, source->keys[i], source->strings[i]);
+ if(error) return error;
+ }
+ return 0;
+}
+
+void LodePNG_Text_clear(LodePNG_Text* text)
+{
+ size_t i;
+ for(i = 0; i < text->num; i++)
+ {
+ string_cleanup(&text->keys[i]);
+ string_cleanup(&text->strings[i]);
+ }
+ free(text->keys);
+ free(text->strings);
+}
+
+unsigned LodePNG_Text_add(LodePNG_Text* text, const char* key, const char* str)
+{
+ char** new_keys = (char**)(realloc(text->keys, sizeof(char*) * (text->num + 1)));
+ char** new_strings = (char**)(realloc(text->strings, sizeof(char*) * (text->num + 1)));
+ if(!new_keys || !new_strings)
+ {
+ free(new_keys);
+ free(new_strings);
+ return 9933; /*alloc fail*/
+ }
+
+ text->num++;
+ text->keys = new_keys;
+ text->strings = new_strings;
+
+ string_init(&text->keys[text->num - 1]);
+ string_set(&text->keys[text->num - 1], key);
+
+ string_init(&text->strings[text->num - 1]);
+ string_set(&text->strings[text->num - 1], str);
+
+ return 0;
+}
+
+/******************************************************************************/
+
+void LodePNG_IText_init(LodePNG_IText* text)
+{
+ text->num = 0;
+ text->keys = NULL;
+ text->langtags = NULL;
+ text->transkeys = NULL;
+ text->strings = NULL;
+}
+
+void LodePNG_IText_cleanup(LodePNG_IText* text)
+{
+ LodePNG_IText_clear(text);
+}
+
+unsigned LodePNG_IText_copy(LodePNG_IText* dest, const LodePNG_IText* source)
+{
+ size_t i = 0;
+ dest->keys = 0;
+ dest->langtags = 0;
+ dest->transkeys = 0;
+ dest->strings = 0;
+ dest->num = 0;
+ for(i = 0; i < source->num; i++)
+ {
+ unsigned error = LodePNG_IText_add(dest, source->keys[i], source->langtags[i],
+ source->transkeys[i], source->strings[i]);
+ if(error) return error;
+ }
+ return 0;
+}
+
+void LodePNG_IText_clear(LodePNG_IText* text)
+{
+ size_t i;
+ for(i = 0; i < text->num; i++)
+ {
+ string_cleanup(&text->keys[i]);
+ string_cleanup(&text->langtags[i]);
+ string_cleanup(&text->transkeys[i]);
+ string_cleanup(&text->strings[i]);
+ }
+ free(text->keys);
+ free(text->langtags);
+ free(text->transkeys);
+ free(text->strings);
+}
+
+unsigned LodePNG_IText_add(LodePNG_IText* text, const char* key, const char* langtag,
+ const char* transkey, const char* str)
+{
+ char** new_keys = (char**)(realloc(text->keys, sizeof(char*) * (text->num + 1)));
+ char** new_langtags = (char**)(realloc(text->langtags, sizeof(char*) * (text->num + 1)));
+ char** new_transkeys = (char**)(realloc(text->transkeys, sizeof(char*) * (text->num + 1)));
+ char** new_strings = (char**)(realloc(text->strings, sizeof(char*) * (text->num + 1)));
+ if(!new_keys || !new_langtags || !new_transkeys || !new_strings)
+ {
+ free(new_keys);
+ free(new_langtags);
+ free(new_transkeys);
+ free(new_strings);
+ return 9934; /*alloc fail*/
+ }
+
+ text->num++;
+ text->keys = new_keys;
+ text->langtags = new_langtags;
+ text->transkeys = new_transkeys;
+ text->strings = new_strings;
+
+ string_init(&text->keys[text->num - 1]);
+ string_set(&text->keys[text->num - 1], key);
+
+ string_init(&text->langtags[text->num - 1]);
+ string_set(&text->langtags[text->num - 1], langtag);
+
+ string_init(&text->transkeys[text->num - 1]);
+ string_set(&text->transkeys[text->num - 1], transkey);
+
+ string_init(&text->strings[text->num - 1]);
+ string_set(&text->strings[text->num - 1], str);
+
+ return 0;
+}
+#endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/
+
+void LodePNG_InfoPng_init(LodePNG_InfoPng* info)
+{
+ info->width = info->height = 0;
+ LodePNG_InfoColor_init(&info->color);
+ info->interlaceMethod = 0;
+ info->compressionMethod = 0;
+ info->filterMethod = 0;
+#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS
+ info->background_defined = 0;
+ info->background_r = info->background_g = info->background_b = 0;
+
+ LodePNG_Text_init(&info->text);
+ LodePNG_IText_init(&info->itext);
+
+ info->time_defined = 0;
+ info->phys_defined = 0;
+#endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/
+#ifdef LODEPNG_COMPILE_UNKNOWN_CHUNKS
+ LodePNG_UnknownChunks_init(&info->unknown_chunks);
+#endif /*LODEPNG_COMPILE_UNKNOWN_CHUNKS*/
+}
+
+void LodePNG_InfoPng_cleanup(LodePNG_InfoPng* info)
+{
+ LodePNG_InfoColor_cleanup(&info->color);
+#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS
+ LodePNG_Text_cleanup(&info->text);
+ LodePNG_IText_cleanup(&info->itext);
+#endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/
+#ifdef LODEPNG_COMPILE_UNKNOWN_CHUNKS
+ LodePNG_UnknownChunks_cleanup(&info->unknown_chunks);
+#endif /*LODEPNG_COMPILE_UNKNOWN_CHUNKS*/
+}
+
+unsigned LodePNG_InfoPng_copy(LodePNG_InfoPng* dest, const LodePNG_InfoPng* source)
+{
+ unsigned error = 0;
+ LodePNG_InfoPng_cleanup(dest);
+ *dest = *source;
+ LodePNG_InfoColor_init(&dest->color);
+ error = LodePNG_InfoColor_copy(&dest->color, &source->color); if(error) return error;
+
+#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS
+ error = LodePNG_Text_copy(&dest->text, &source->text); if(error) return error;
+ error = LodePNG_IText_copy(&dest->itext, &source->itext); if(error) return error;
+#endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/
+
+#ifdef LODEPNG_COMPILE_UNKNOWN_CHUNKS
+ LodePNG_UnknownChunks_init(&dest->unknown_chunks);
+ error = LodePNG_UnknownChunks_copy(&dest->unknown_chunks, &source->unknown_chunks); if(error) return error;
+#endif /*LODEPNG_COMPILE_UNKNOWN_CHUNKS*/
+ return error;
+}
+
+void LodePNG_InfoPng_swap(LodePNG_InfoPng* a, LodePNG_InfoPng* b)
+{
+ LodePNG_InfoPng temp = *a;
+ *a = *b;
+ *b = temp;
+}
+
+unsigned LodePNG_InfoColor_copy(LodePNG_InfoColor* dest, const LodePNG_InfoColor* source)
+{
+ size_t i;
+ LodePNG_InfoColor_cleanup(dest);
+ *dest = *source;
+ dest->palette = (unsigned char*)malloc(source->palettesize * 4);
+ if(!dest->palette && source->palettesize) return 9935; /*alloc fail*/
+ for(i = 0; i < source->palettesize * 4; i++) dest->palette[i] = source->palette[i];
+ return 0;
+}
+
+void LodePNG_InfoRaw_init(LodePNG_InfoRaw* info)
+{
+ LodePNG_InfoColor_init(&info->color);
+}
+
+void LodePNG_InfoRaw_cleanup(LodePNG_InfoRaw* info)
+{
+ LodePNG_InfoColor_cleanup(&info->color);
+}
+
+unsigned LodePNG_InfoRaw_copy(LodePNG_InfoRaw* dest, const LodePNG_InfoRaw* source)
+{
+ unsigned error = 0;
+ LodePNG_InfoRaw_cleanup(dest);
+ *dest = *source;
+ LodePNG_InfoColor_init(&dest->color);
+ error = LodePNG_InfoColor_copy(&dest->color, &source->color);
+ return error; /*this variable could be removed, but it's more clear what is returned this way*/
+}
+
+/* ////////////////////////////////////////////////////////////////////////// */
+
+/*convert from any color type to RGB or RGBA with 8 bits per sample*/
+static unsigned LodePNG_convert_rgb_a_8(unsigned char* out, const unsigned char* in,
+ LodePNG_InfoColor* infoIn, size_t numpixels, unsigned bytes, unsigned alpha)
+{
+ size_t i, c, bp = 0; /*bp = bitpointer, used by less-than-8-bit color types*/
+
+ if(infoIn->bitDepth == 8)
+ {
+ switch(infoIn->colorType)
+ {
+ case 0: /*greyscale color*/
+ for(i = 0; i < numpixels; i++)
+ {
+ out[bytes * i + 0] = out[bytes * i + 1] = out[bytes * i + 2] = in[i];
+ if(alpha) out[bytes * i + 3] = infoIn->key_defined && in[i] == infoIn->key_r ? 0 : 255;
+ }
+ break;
+ case 2: /*RGB color*/
+ for(i = 0; i < numpixels; i++)
+ {
+ for(c = 0; c < 3; c++) out[bytes * i + c] = in[3 * i + c];
+ if(alpha)
+ {
+ if(infoIn->key_defined == 1 && in[3 * i + 0] == infoIn->key_r
+ && in[3 * i + 1] == infoIn->key_g && in[3 * i + 2] == infoIn->key_b)
+ out[bytes * i + 3] = 0;
+ else out[bytes * i + 3] = 255;
+ }
+ }
+ break;
+ case 3: /*indexed color (palette)*/
+ for(i = 0; i < numpixels; i++)
+ {
+ if(in[i] >= infoIn->palettesize) return 46; /*invalid palette index*/
+ for(c = 0; c < bytes; c++) out[bytes * i + c] = infoIn->palette[4 * in[i] + c];
+ }
+ break;
+ case 4: /*greyscale with alpha*/
+ for(i = 0; i < numpixels; i++)
+ {
+ out[bytes * i + 0] = out[bytes * i + 1] = out[bytes * i + 2] = in[2 * i + 0];
+ if(alpha) out[bytes * i + 3] = in[2 * i + 1];
+ }
+ break;
+ case 6: /*RGB with alpha*/
+ for(i = 0; i < numpixels; i++)
+ {
+ for(c = 0; c < bytes; c++) out[bytes * i + c] = in[4 * i + c];
+ }
+ break;
+ default: break;
+ }
+ }
+ else if(infoIn->bitDepth == 16)
+ {
+ switch(infoIn->colorType)
+ {
+ case 0: /*greyscale color*/
+ for(i = 0; i < numpixels; i++)
+ {
+ out[bytes * i + 0] = out[bytes * i + 1] = out[bytes * i + 2] = in[2 * i];
+ if(alpha) out[bytes * i + 3] = infoIn->key_defined && 256U * in[i] + in[i + 1] == infoIn->key_r ? 0 : 255;
+ }
+ break;
+ case 2: /*RGB color*/
+ for(i = 0; i < numpixels; i++)
+ {
+ if(alpha) out[bytes * i + 3] = 255;
+ for(c = 0; c < 3; c++) out[bytes * i + c] = in[6 * i + 2 * c];
+ if(alpha)
+ {
+ if(infoIn->key_defined && 256U * in[6 * i + 0] + in[6 * i + 1] == infoIn->key_r
+ && 256U * in[6 * i + 2] + in[6 * i + 3] == infoIn->key_g
+ && 256U * in[6 * i + 4] + in[6 * i + 5] == infoIn->key_b)
+ out[bytes * i + 3] = 0;
+ else out[bytes * i + 3] = 255;
+ }
+ }
+ break;
+ case 4: /*greyscale with alpha*/
+ for(i = 0; i < numpixels; i++)
+ {
+ out[bytes * i + 0] = out[bytes * i + 1] = out[bytes * i + 2] = in[4 * i];
+ if(alpha) out[bytes * i + 3] = in[4 * i + 2];
+ }
+ break;
+ case 6: /*RGB with alpha*/
+ for(i = 0; i < numpixels; i++)
+ {
+ for(c = 0; c < bytes; c++) out[bytes * i + c] = in[8 * i + 2 * c];
+ }
+ break;
+ default: break;
+ }
+ }
+ else /*infoIn->bitDepth is less than 8 bit per channel*/
+ {
+ switch(infoIn->colorType)
+ {
+ case 0: /*greyscale color*/
+ for(i = 0; i < numpixels; i++)
+ {
+ unsigned value = readBitsFromReversedStream(&bp, in, infoIn->bitDepth);
+ unsigned highest = ((1U << infoIn->bitDepth) - 1U); /*highest possible value for this bit depth*/
+ /*scale value from 0 to 255*/
+ out[bytes * i + 0] = out[bytes * i + 1] = out[bytes * i + 2]
+ = (unsigned char)((value * 255) / highest);
+ if(alpha) out[bytes * i + 3] = infoIn->key_defined && value == infoIn->key_r ? 0 : 255;
+ }
+ break;
+ case 3: /*indexed color (palette)*/
+ for(i = 0; i < numpixels; i++)
+ {
+ unsigned value = readBitsFromReversedStream(&bp, in, infoIn->bitDepth);
+ if(value >= infoIn->palettesize) return 47;
+ for(c = 0; c < bytes; c++) out[bytes * i + c] = infoIn->palette[4 * value + c];
+ }
+ break;
+ default: break;
+ }
+ }
+ return 0;
+}
+
+/*convert from any greyscale color type to 8-bit greyscale with or without alpha channel*/
+static unsigned LodePNG_convert_grey_8(unsigned char* out, const unsigned char* in,
+ LodePNG_InfoColor* infoIn, size_t numpixels, unsigned bytes, unsigned alpha)
+{
+ size_t i, bp = 0; /*bp = bitpointer, used by less-than-8-bit color types*/
+
+ if(infoIn->bitDepth == 8)
+ {
+ switch(infoIn->colorType)
+ {
+ case 0: /*greyscale color*/
+ for(i = 0; i < numpixels; i++)
+ {
+ out[bytes * i] = in[i];
+ if(alpha) out[bytes * i + 1] = infoIn->key_defined && in[i] == infoIn->key_r ? 0 : 255;
+ }
+ break;
+ case 4: /*greyscale with alpha*/
+ for(i = 0; i < numpixels; i++)
+ {
+ out[bytes * i + 0] = in[2 * i + 0];
+ if(alpha) out[bytes * i + 1] = in[2 * i + 1];
+ }
+ break;
+ default: return 31;
+ }
+ }
+ else if(infoIn->bitDepth == 16)
+ {
+ switch(infoIn->colorType)
+ {
+ case 0: /*greyscale color*/
+ for(i = 0; i < numpixels; i++)
+ {
+ if(alpha) out[bytes * i + 1] = 255;
+ out[bytes * i] = in[2 * i];
+ if(alpha && infoIn->key_defined && 256U * in[i] + in[i + 1] == infoIn->key_r)
+ {
+ out[bytes * i + 1] = 0;
+ }
+ }
+ break;
+ case 4: /*greyscale with alpha*/
+ for(i = 0; i < numpixels; i++)
+ {
+ out[bytes * i] = in[4 * i]; /*most significant byte*/
+ if(alpha) out[bytes * i + 1] = in[4 * i + 2]; /*most significant byte*/
+ }
+ break;
+ default: return 31;
+ }
+ }
+ else /*infoIn->bitDepth is less than 8 bit per channel*/
+ {
+ if(infoIn->colorType != 0) return 31; /*colorType 0 is the only greyscale type with < 8 bits per channel*/
+ for(i = 0; i < numpixels; i++)
+ {
+ unsigned value = readBitsFromReversedStream(&bp, in, infoIn->bitDepth);
+ unsigned highest = ((1U << infoIn->bitDepth) - 1U); /*highest possible value for this bit depth*/
+ out[bytes * i] = (unsigned char)((value * 255) / highest); /*scale value from 0 to 255*/
+ if(alpha)
+ {
+ if(infoIn->key_defined && value == infoIn->key_r) out[bytes * i + 1] = 0;
+ else out[bytes * i + 1] = 255;
+ }
+ }
+ }
+ return 0;
+}
+
+/*convert from any color type to RGB or RGBA with 8 bits per sample*/
+static unsigned LodePNG_convert_rgb_a_16(unsigned char* out, const unsigned char* in,
+ LodePNG_InfoColor* infoIn, size_t numpixels, unsigned bytes, unsigned alpha)
+{
+ size_t i, c, bp = 0; /*bp = bitpointer, used by less-than-8-bit color types*/
+
+ if(infoIn->bitDepth == 8)
+ {
+ switch(infoIn->colorType)
+ {
+ case 0: /*greyscale color*/
+ for(i = 0; i < numpixels; i++)
+ {
+ out[bytes * i + 0] = out[bytes * i + 2] = out[bytes * i + 4] = in[i];
+ out[bytes * i + 1] = out[bytes * i + 3] = out[bytes * i + 5] = in[i];
+ if(alpha)
+ {
+ if(alpha && infoIn->key_defined && in[i] == infoIn->key_r) out[bytes * i + 6] = out[bytes * i + 7] = 0;
+ else out[bytes * i + 6] = out[bytes * i + 7] = 255;
+ }
+ }
+ break;
+ case 2: /*RGB color*/
+ for(i = 0; i < numpixels; i++)
+ {
+ out[bytes * i + 0] = out[bytes * i + 1] = in[3 * i + 0];
+ out[bytes * i + 2] = out[bytes * i + 3] = in[3 * i + 1];
+ out[bytes * i + 4] = out[bytes * i + 5] = in[3 * i + 2];
+ if(alpha)
+ {
+ if(infoIn->key_defined == 1 && in[3 * i + 0] == infoIn->key_r
+ && in[3 * i + 1] == infoIn->key_g && in[3 * i + 2] == infoIn->key_b)
+ out[bytes * i + 6] = out[bytes * i + 7] = 0;
+ else out[bytes * i + 6] = out[bytes * i + 7] = 255;
+ }
+ }
+ break;
+ case 3: /*indexed color (palette)*/
+ for(i = 0; i < numpixels; i++)
+ {
+ if(in[i] >= infoIn->palettesize) return 46; /*invalid palette index*/
+ for(c = 0; c < bytes; c++)
+ {
+ out[bytes * i + 2 * c] = out[bytes * i + 2 * c + 1] = infoIn->palette[4 * in[i] + c];
+ }
+ }
+ break;
+ case 4: /*greyscale with alpha*/
+ for(i = 0; i < numpixels; i++)
+ {
+ out[bytes * i + 0] = out[bytes * i + 2] = out[bytes * i + 4] = in[i];
+ out[bytes * i + 1] = out[bytes * i + 3] = out[bytes * i + 5] = in[i];
+ if(alpha)
+ {
+ out[bytes * i + 6] = out[bytes * i + 7] = in[2 * i + 1];
+ }
+ }
+ break;
+ case 6: /*RGB with alpha*/
+ for(i = 0; i < numpixels; i++)
+ {
+ for(c = 0; c < 3; c++)
+ {
+ out[bytes * i + 2 * c] = out[bytes * i + 2 * c + 1] = in[4 * i + c];
+ }
+ if(alpha)
+ {
+ out[bytes * i + 6] = out[bytes * i + 7] = in[4 * i + c];
+ }
+ }
+ break;
+ default: break;
+ }
+ }
+ else if(infoIn->bitDepth == 16)
+ {
+ switch(infoIn->colorType)
+ {
+ case 0: /*greyscale color*/
+ for(i = 0; i < numpixels; i++)
+ {
+ out[bytes * i + 0] = out[bytes * i + 2] = out[bytes * i + 4] = in[2 * i];
+ out[bytes * i + 1] = out[bytes * i + 3] = out[bytes * i + 5] = in[2 * i + 1];
+ if(alpha)
+ {
+ if(infoIn->key_defined && 256U * in[i] + in[i + 1] == infoIn->key_r)
+ out[bytes * i + 6] = out[bytes * i + 7] = 0;
+ else out[bytes * i + 6] = out[bytes * i + 7] = 255;
+ }
+ }
+ break;
+ case 2: /*RGB color*/
+ for(i = 0; i < numpixels; i++)
+ {
+ for(c = 0; c < 6; c++) out[bytes * i + c] = in[6 * i + c];
+ if(alpha)
+ {
+ if(infoIn->key_defined && 256U * in[6 * i + 0] + in[6 * i + 1] == infoIn->key_r
+ && 256U * in[6 * i + 2] + in[6 * i + 3] == infoIn->key_g
+ && 256U * in[6 * i + 4] + in[6 * i + 5] == infoIn->key_b)
+ out[bytes * i + 6] = out[bytes * i + 7] = 0;
+ else out[bytes * i + 6] = out[bytes * i + 7] = 255;
+ }
+ }
+ break;
+ case 4: /*greyscale with alpha*/
+ for(i = 0; i < numpixels; i++)
+ {
+ out[bytes * i + 0] = out[bytes * i + 2] = out[bytes * i + 4] = in[4 * i + 0];
+ out[bytes * i + 1] = out[bytes * i + 3] = out[bytes * i + 5] = in[4 * i + 1];
+ if(alpha)
+ {
+ out[bytes * i + 6] = in[4 * i + 2];
+ out[bytes * i + 7] = in[4 * i + 3];
+ }
+ }
+ break;
+ case 6: /*RGB with alpha*/
+ for(i = 0; i < numpixels; i++)
+ {
+ for(c = 0; c < bytes; c++) out[bytes * i + c] = in[8 * i + 2 * c];
+ }
+ break;
+ default: break;
+ }
+ }
+ else /*infoIn->bitDepth is less than 8 bit per channel*/
+ {
+ switch(infoIn->colorType)
+ {
+ case 0: /*greyscale color*/
+ for(i = 0; i < numpixels; i++)
+ {
+ unsigned value = readBitsFromReversedStream(&bp, in, infoIn->bitDepth);
+ unsigned highest = ((1U << infoIn->bitDepth) - 1U); /*highest possible value for this bit depth*/
+ /*scale value from 0 to 255*/
+ out[bytes * i + 0] = out[bytes * i + 2] = out[bytes * i + 4]
+ = out[bytes * i + 1] = out[bytes * i + 3]
+ = out[bytes * i + 5] = (unsigned char)((value * 255) / highest);
+ if(alpha)
+ {
+ if(infoIn->key_defined && value == infoIn->key_r) out[bytes * i + 6] = out[bytes * i + 7] = 0;
+ else out[bytes * i + 6] = out[bytes * i + 7] = 255;
+ }
+ }
+ break;
+ case 3: /*indexed color (palette)*/
+ for(i = 0; i < numpixels; i++)
+ {
+ unsigned value = readBitsFromReversedStream(&bp, in, infoIn->bitDepth);
+ if(value >= infoIn->palettesize) return 47;
+ for(c = 0; c < bytes / 2; c++)
+ {
+ out[bytes * i + c * 2 + 0] = out[bytes * i + c * 2 + 1] = infoIn->palette[4 * value + c];
+ }
+ }
+ break;
+ default: break;
+ }
+ }
+ return 0;
+}
+
+/*convert from any greyscale color type to 16-bit greyscale with or without alpha channel*/
+static unsigned LodePNG_convert_grey_16(unsigned char* out, const unsigned char* in,
+ LodePNG_InfoColor* infoIn, size_t numpixels, unsigned bytes, unsigned alpha)
+{
+ size_t i, c, bp = 0; /*bp = bitpointer, used by less-than-8-bit color types*/
+
+ if(infoIn->bitDepth == 8)
+ {
+ switch(infoIn->colorType)
+ {
+ case 0: /*greyscale color*/
+ for(i = 0; i < numpixels; i++)
+ {
+ out[bytes * i] = out[bytes * i + 1] = in[i];
+ if(alpha)
+ {
+ if(infoIn->key_defined && in[i] == infoIn->key_r) out[bytes * i + 2] = out[bytes * i + 3] = 0;
+ else out[bytes * i + 2] = out[bytes * i + 3] = 255;
+ }
+ }
+ break;
+ case 4: /*greyscale with alpha*/
+ for(i = 0; i < numpixels; i++)
+ {
+ out[bytes * i + 0] = out[bytes * i + 1] = in[2 * i + 0];
+ if(alpha) out[bytes * i + 2] = out[bytes * i + 3] = in[2 * i + 1];
+ }
+ break;
+ default: return 31;
+ }
+ }
+ else if(infoIn->bitDepth == 16)
+ {
+ switch(infoIn->colorType)
+ {
+ case 0: /*greyscale color*/
+ for(i = 0; i < numpixels; i++)
+ {
+ out[bytes * i + 0] = in[2 * i + 0];
+ out[bytes * i + 1] = in[2 * i + 1];
+ if(alpha)
+ {
+ if(infoIn->key_defined && 256U * in[i] + in[i + 1] == infoIn->key_r)
+ out[bytes * i + 2] = out[bytes * i + 3] = 0;
+ else out[bytes * i + 2] = out[bytes * i + 3] = 255;
+ }
+ }
+ break;
+ case 4: /*greyscale with alpha*/
+ for(i = 0; i < numpixels; i++)
+ {
+ for(c = 0; c < bytes; c++) out[bytes * i + c] = in[4 * i + c];
+ }
+ break;
+ default: return 31;
+ }
+ }
+ else /*infoIn->bitDepth is less than 8 bit per channel*/
+ {
+ if(infoIn->colorType != 0) return 31; /*colorType 0 is the only greyscale type with < 8 bits per channel*/
+ for(i = 0; i < numpixels; i++)
+ {
+ unsigned value = readBitsFromReversedStream(&bp, in, infoIn->bitDepth);
+ unsigned highest = ((1U << infoIn->bitDepth) - 1U); /*highest possible value for this bit depth*/
+ out[bytes * i] = out[bytes * i + 1] = (unsigned char)((value * 255) / highest); /*scale value from 0 to 255*/
+ if(alpha)
+ {
+ if(infoIn->key_defined && value == infoIn->key_r) out[bytes * i + 2] = out[bytes * i + 3] = 0;
+ else out[bytes * i + 2] = out[bytes * i + 3] = 255;
+ }
+ }
+ }
+ return 0;
+}
+
+/*
+converts from any color type to 24-bit or 32-bit (later maybe more supported). return value = LodePNG error code
+the out buffer must have (w * h * bpp + 7) / 8 bytes, where bpp is the bits per pixel of the output color type
+(LodePNG_InfoColor_getBpp) for < 8 bpp images, there may _not_ be padding bits at the end of scanlines.
+*/
+unsigned LodePNG_convert(unsigned char* out, const unsigned char* in, LodePNG_InfoColor* infoOut,
+ LodePNG_InfoColor* infoIn, unsigned w, unsigned h)
+{
+ size_t numpixels = w * h; /*amount of pixels*/
+ unsigned bytes = LodePNG_InfoColor_getBpp(infoOut) / 8; /*bytes per pixel in the output image*/
+ unsigned alpha = LodePNG_InfoColor_isAlphaType(infoOut); /*use 8-bit alpha channel*/
+
+ /*cases where in and out already have the same format*/
+ if(LodePNG_InfoColor_equal(infoIn, infoOut))
+ {
+ size_t i;
+ size_t size = (numpixels * LodePNG_InfoColor_getBpp(infoIn) + 7) / 8;
+ for(i = 0; i < size; i++) out[i] = in[i];
+ return 0;
+ }
+ else if((infoOut->colorType == 2 || infoOut->colorType == 6) && infoOut->bitDepth == 8)
+ {
+ LodePNG_convert_rgb_a_8(out, in, infoIn, numpixels, bytes, alpha);
+ }
+ else if(LodePNG_InfoColor_isGreyscaleType(infoOut) && infoOut->bitDepth == 8)
+ {
+ /*conversion from greyscale to greyscale*/
+ if(!LodePNG_InfoColor_isGreyscaleType(infoIn)) return 62; /*converting from color to grey is not supported*/
+ LodePNG_convert_grey_8(out, in, infoIn, numpixels, bytes, alpha);
+ }
+ else if((infoOut->colorType == 2 || infoOut->colorType == 6) && infoOut->bitDepth == 16)
+ {
+ LodePNG_convert_rgb_a_16(out, in, infoIn, numpixels, bytes, alpha);
+ }
+ else if(LodePNG_InfoColor_isGreyscaleType(infoOut) && infoOut->bitDepth == 16)
+ {
+ /*conversion from greyscale to greyscale*/
+ if(!LodePNG_InfoColor_isGreyscaleType(infoIn)) return 62; /*converting from color to grey is not supported*/
+ LodePNG_convert_grey_16(out, in, infoIn, numpixels, bytes, alpha);
+ }
+ else return 59; /*invalid color mode*/
+ return 0;
+}
+
+/*
+Paeth predicter, used by PNG filter type 4
+The parameters are of type short, but should come from unsigned chars, the shorts
+are only needed to make the paeth calculation correct.
+*/
+static unsigned char paethPredictor(short a, short b, short c)
+{
+ short pa = abs(b - c);
+ short pb = abs(a - c);
+ short pc = abs(a + b - c - c);
+
+ /*short pc = a + b - c;
+ short pa = abs(pc - a);
+ short pb = abs(pc - b);
+ pc = abs(pc - c);*/
+
+ if(pa <= pb && pa <= pc) return (unsigned char)a;
+ else if(pb <= pc) return (unsigned char)b;
+ else return (unsigned char)c;
+}
+
+/*shared values used by multiple Adam7 related functions*/
+
+static const unsigned ADAM7_IX[7] = { 0, 4, 0, 2, 0, 1, 0 }; /*x start values*/
+static const unsigned ADAM7_IY[7] = { 0, 0, 4, 0, 2, 0, 1 }; /*y start values*/
+static const unsigned ADAM7_DX[7] = { 8, 8, 4, 4, 2, 2, 1 }; /*x delta values*/
+static const unsigned ADAM7_DY[7] = { 8, 8, 8, 4, 4, 2, 2 }; /*y delta values*/
+
+static void Adam7_getpassvalues(unsigned passw[7], unsigned passh[7], size_t filter_passstart[8],
+ size_t padded_passstart[8], size_t passstart[8], unsigned w, unsigned h, unsigned bpp)
+{
+ /*the passstart values have 8 values: the 8th one indicates the byte after the end of the 7th (= last) pass*/
+ unsigned i;
+
+ /*calculate width and height in pixels of each pass*/
+ for(i = 0; i < 7; i++)
+ {
+ passw[i] = (w + ADAM7_DX[i] - ADAM7_IX[i] - 1) / ADAM7_DX[i];
+ passh[i] = (h + ADAM7_DY[i] - ADAM7_IY[i] - 1) / ADAM7_DY[i];
+ if(passw[i] == 0) passh[i] = 0;
+ if(passh[i] == 0) passw[i] = 0;
+ }
+
+ filter_passstart[0] = padded_passstart[0] = passstart[0] = 0;
+ for(i = 0; i < 7; i++)
+ {
+ /*if passw[i] is 0, it's 0 bytes, not 1 (no filtertype-byte)*/
+ filter_passstart[i + 1] = filter_passstart[i]
+ + ((passw[i] && passh[i]) ? passh[i] * (1 + (passw[i] * bpp + 7) / 8) : 0);
+ /*bits padded if needed to fill full byte at end of each scanline*/
+ padded_passstart[i + 1] = padded_passstart[i] + passh[i] * ((passw[i] * bpp + 7) / 8);
+ /*only padded at end of reduced image*/
+ passstart[i + 1] = passstart[i] + (passh[i] * passw[i] * bpp + 7) / 8;
+ }
+}
+
+#ifdef LODEPNG_COMPILE_DECODER
+
+/* ////////////////////////////////////////////////////////////////////////// */
+/* / PNG Decoder / */
+/* ////////////////////////////////////////////////////////////////////////// */
+
+/*read the information from the header and store it in the LodePNG_Info. return value is error*/
+void LodePNG_Decoder_inspect(LodePNG_Decoder* decoder, const unsigned char* in, size_t inlength)
+{
+ if(inlength == 0 || in == 0)
+ {
+ decoder->error = 48; /*the given data is empty*/
+ return;
+ }
+ if(inlength < 29)
+ {
+ decoder->error = 27; /*error: the data length is smaller than the length of a PNG header*/
+ return;
+ }
+
+ /*when decoding a new PNG image, make sure all parameters created after previous decoding are reset*/
+ LodePNG_InfoPng_cleanup(&decoder->infoPng);
+ LodePNG_InfoPng_init(&decoder->infoPng);
+ decoder->error = 0;
+
+ if(in[0] != 137 || in[1] != 80 || in[2] != 78 || in[3] != 71
+ || in[4] != 13 || in[5] != 10 || in[6] != 26 || in[7] != 10)
+ {
+ decoder->error = 28; /*error: the first 8 bytes are not the correct PNG signature*/
+ return;
+ }
+ if(in[12] != 'I' || in[13] != 'H' || in[14] != 'D' || in[15] != 'R')
+ {
+ decoder->error = 29; /*error: it doesn't start with a IHDR chunk!*/
+ return;
+ }
+
+ /*read the values given in the header*/
+ decoder->infoPng.width = LodePNG_read32bitInt(&in[16]);
+ decoder->infoPng.height = LodePNG_read32bitInt(&in[20]);
+ decoder->infoPng.color.bitDepth = in[24];
+ decoder->infoPng.color.colorType = in[25];
+ decoder->infoPng.compressionMethod = in[26];
+ decoder->infoPng.filterMethod = in[27];
+ decoder->infoPng.interlaceMethod = in[28];
+
+ if(!decoder->settings.ignoreCrc)
+ {
+ unsigned CRC = LodePNG_read32bitInt(&in[29]);
+ unsigned checksum = Crc32_crc(&in[12], 17);
+ if(CRC != checksum)
+ {
+ decoder->error = 57; /*invalid CRC*/
+ return;
+ }
+ }
+
+ /*error: only compression method 0 is allowed in the specification*/
+ if(decoder->infoPng.compressionMethod != 0) { decoder->error = 32; return; }
+ /*error: only filter method 0 is allowed in the specification*/
+ if(decoder->infoPng.filterMethod != 0) { decoder->error = 33; return; }
+ /*error: only interlace methods 0 and 1 exist in the specification*/
+ if(decoder->infoPng.interlaceMethod > 1) { decoder->error = 34; return; }
+
+ decoder->error = checkColorValidity(decoder->infoPng.color.colorType, decoder->infoPng.color.bitDepth);
+}
+
+static unsigned unfilterScanline(unsigned char* recon, const unsigned char* scanline, const unsigned char* precon,
+ size_t bytewidth, unsigned char filterType, size_t length)
+{
+ /*
+ For PNG filter method 0
+ unfilter a PNG image scanline by scanline. when the pixels are smaller than 1 byte,
+ the filter works byte per byte (bytewidth = 1)
+ precon is the previous unfiltered scanline, recon the result, scanline the current one
+ the incoming scanlines do NOT include the filtertype byte, that one is given in the parameter filterType instead
+ recon and scanline MAY be the same memory address! precon must be disjoint.
+ */
+
+ size_t i;
+ switch(filterType)
+ {
+ case 0:
+ for(i = 0; i < length; i++) recon[i] = scanline[i];
+ break;
+ case 1:
+ for(i = 0; i < bytewidth; i++) recon[i] = scanline[i];
+ for(i = bytewidth; i < length; i++) recon[i] = scanline[i] + recon[i - bytewidth];
+ break;
+ case 2:
+ if(precon)
+ {
+ for(i = 0; i < length; i++) recon[i] = scanline[i] + precon[i];
+ }
+ else
+ {
+ for(i = 0; i < length; i++) recon[i] = scanline[i];
+ }
+ break;
+ case 3:
+ if(precon)
+ {
+ for(i = 0; i < bytewidth; i++) recon[i] = scanline[i] + precon[i] / 2;
+ for(i = bytewidth; i < length; i++) recon[i] = scanline[i] + ((recon[i - bytewidth] + precon[i]) / 2);
+ }
+ else
+ {
+ for(i = 0; i < bytewidth; i++) recon[i] = scanline[i];
+ for(i = bytewidth; i < length; i++) recon[i] = scanline[i] + recon[i - bytewidth] / 2;
+ }
+ break;
+ case 4:
+ if(precon)
+ {
+ for(i = 0; i < bytewidth; i++)
+ {
+ recon[i] = (scanline[i] + precon[i]); /*paethPredictor(0, precon[i], 0) is always precon[i]*/
+ }
+ for(i = bytewidth; i < length; i++)
+ {
+ recon[i] = (scanline[i] + paethPredictor(recon[i - bytewidth], precon[i], precon[i - bytewidth]));
+ }
+ }
+ else
+ {
+ for(i = 0; i < bytewidth; i++)
+ {
+ recon[i] = scanline[i];
+ }
+ for(i = bytewidth; i < length; i++)
+ {
+ /*paethPredictor(recon[i - bytewidth], 0, 0) is always recon[i - bytewidth]*/
+ recon[i] = (scanline[i] + recon[i - bytewidth]);
+ }
+ }
+ break;
+ default: return 36; /*error: unexisting filter type given*/
+ }
+ return 0;
+}
+
+static unsigned unfilter(unsigned char* out, const unsigned char* in, unsigned w, unsigned h, unsigned bpp)
+{
+ /*
+ For PNG filter method 0
+ this function unfilters a single image (e.g. without interlacing this is called once, with Adam7 seven times)
+ out must have enough bytes allocated already, in must have the scanlines + 1 filtertype byte per scanline
+ w and h are image dimensions or dimensions of reduced image, bpp is bits per pixel
+ in and out are allowed to be the same memory address (but aren't the same size since in has the extra filter bytes)
+ */
+
+ unsigned y;
+ unsigned char* prevline = 0;
+
+ /*bytewidth is used for filtering, is 1 when bpp < 8, number of bytes per pixel otherwise*/
+ size_t bytewidth = (bpp + 7) / 8;
+ size_t linebytes = (w * bpp + 7) / 8;
+
+ for(y = 0; y < h; y++)
+ {
+ size_t outindex = linebytes * y;
+ size_t inindex = (1 + linebytes) * y; /*the extra filterbyte added to each row*/
+ unsigned char filterType = in[inindex];
+
+ unsigned error = unfilterScanline(&out[outindex], &in[inindex + 1], prevline, bytewidth, filterType, linebytes);
+ if(error) return error;
+
+ prevline = &out[outindex];
+ }
+
+ return 0;
+}
+
+static void Adam7_deinterlace(unsigned char* out, const unsigned char* in, unsigned w, unsigned h, unsigned bpp)
+{
+ /*Note: this function works on image buffers WITHOUT padding bits at end of scanlines
+ with non-multiple-of-8 bit amounts, only between reduced images is padding
+ out must be big enough AND must be 0 everywhere if bpp < 8 in the current implementation
+ (because that's likely a little bit faster)*/
+ unsigned passw[7], passh[7];
+ size_t filter_passstart[8], padded_passstart[8], passstart[8];
+ unsigned i;
+
+ Adam7_getpassvalues(passw, passh, filter_passstart, padded_passstart, passstart, w, h, bpp);
+
+ if(bpp >= 8)
+ {
+ for(i = 0; i < 7; i++)
+ {
+ unsigned x, y, b;
+ size_t bytewidth = bpp / 8;
+ for(y = 0; y < passh[i]; y++)
+ for(x = 0; x < passw[i]; x++)
+ {
+ size_t pixelinstart = passstart[i] + (y * passw[i] + x) * bytewidth;
+ size_t pixeloutstart = ((ADAM7_IY[i] + y * ADAM7_DY[i]) * w + ADAM7_IX[i] + x * ADAM7_DX[i]) * bytewidth;
+ for(b = 0; b < bytewidth; b++)
+ {
+ out[pixeloutstart + b] = in[pixelinstart + b];
+ }
+ }
+ }
+ }
+ else /*bpp < 8: Adam7 with pixels < 8 bit is a bit trickier: with bit pointers*/
+ {
+ for(i = 0; i < 7; i++)
+ {
+ unsigned x, y, b;
+ unsigned ilinebits = bpp * passw[i];
+ unsigned olinebits = bpp * w;
+ size_t obp, ibp; /*bit pointers (for out and in buffer)*/
+ for(y = 0; y < passh[i]; y++)
+ for(x = 0; x < passw[i]; x++)
+ {
+ ibp = (8 * passstart[i]) + (y * ilinebits + x * bpp);
+ obp = (ADAM7_IY[i] + y * ADAM7_DY[i]) * olinebits + (ADAM7_IX[i] + x * ADAM7_DX[i]) * bpp;
+ for(b = 0; b < bpp; b++)
+ {
+ unsigned char bit = readBitFromReversedStream(&ibp, in);
+ /*note that this function assumes the out buffer is completely 0, use setBitOfReversedStream otherwise*/
+ setBitOfReversedStream0(&obp, out, bit);
+ }
+ }
+ }
+ }
+}
+
+static void removePaddingBits(unsigned char* out, const unsigned char* in,
+ size_t olinebits, size_t ilinebits, unsigned h)
+{
+ /*
+ After filtering there are still padding bits if scanlines have non multiple of 8 bit amounts. They need
+ to be removed (except at last scanline of (Adam7-reduced) image) before working with pure image buffers
+ for the Adam7 code, the color convert code and the output to the user.
+ in and out are allowed to be the same buffer, in may also be higher but still overlapping; in must
+ have >= ilinebits*h bits, out must have >= olinebits*h bits, olinebits must be <= ilinebits
+ also used to move bits after earlier such operations happened, e.g. in a sequence of reduced images from Adam7
+ only useful if (ilinebits - olinebits) is a value in the range 1..7
+ */
+ unsigned y;
+ size_t diff = ilinebits - olinebits;
+ size_t ibp = 0, obp = 0; /*input and output bit pointers*/
+ for(y = 0; y < h; y++)
+ {
+ size_t x;
+ for(x = 0; x < olinebits; x++)
+ {
+ unsigned char bit = readBitFromReversedStream(&ibp, in);
+ setBitOfReversedStream(&obp, out, bit);
+ }
+ ibp += diff;
+ }
+}
+
+/*out must be buffer big enough to contain full image, and in must contain the full decompressed data from
+the IDAT chunks (with filter index bytes and possible padding bits)
+return value is error*/
+static unsigned postProcessScanlines(unsigned char* out, unsigned char* in, const LodePNG_InfoPng* infoPng)
+{
+ /*
+ This function converts the filtered-padded-interlaced data into pure 2D image buffer with the PNG's colortype.
+ Steps:
+ *) if no Adam7: 1) unfilter 2) remove padding bits (= posible extra bits per scanline if bpp < 8)
+ *) if adam7: 1) 7x unfilter 2) 7x remove padding bits 3) Adam7_deinterlace
+ NOTE: the in buffer will be overwritten with intermediate data!
+ */
+ unsigned bpp = LodePNG_InfoColor_getBpp(&infoPng->color);
+ unsigned w = infoPng->width;
+ unsigned h = infoPng->height;
+ unsigned error = 0;
+ if(bpp == 0) return 31; /*error: invalid colortype*/
+
+ if(infoPng->interlaceMethod == 0)
+ {
+ if(bpp < 8 && w * bpp != ((w * bpp + 7) / 8) * 8)
+ {
+ error = unfilter(in, in, w, h, bpp);
+ if(error) return error;
+ removePaddingBits(out, in, w * bpp, ((w * bpp + 7) / 8) * 8, h);
+ }
+ else error = unfilter(out, in, w, h, bpp); /*we can immediatly filter into the out buffer, no other steps needed*/
+ }
+ else /*interlaceMethod is 1 (Adam7)*/
+ {
+ unsigned passw[7], passh[7]; size_t filter_passstart[8], padded_passstart[8], passstart[8];
+ unsigned i;
+
+ Adam7_getpassvalues(passw, passh, filter_passstart, padded_passstart, passstart, w, h, bpp);
+
+ for(i = 0; i < 7; i++)
+ {
+ error = unfilter(&in[padded_passstart[i]], &in[filter_passstart[i]], passw[i], passh[i], bpp);
+ if(error) return error;
+ /*TODO: possible efficiency improvement: if in this reduced image the bits fit nicely in 1 scanline,
+ move bytes instead of bits or move not at all*/
+ if(bpp < 8)
+ {
+ /*remove padding bits in scanlines; after this there still may be padding
+ bits between the different reduced images: each reduced image still starts nicely at a byte*/
+ removePaddingBits(&in[passstart[i]], &in[padded_passstart[i]], passw[i] * bpp,
+ ((passw[i] * bpp + 7) / 8) * 8, passh[i]);
+ }
+ }
+
+ Adam7_deinterlace(out, in, w, h, bpp);
+ }
+
+ return error;
+}
+
+/*read a PNG, the result will be in the same color type as the PNG (hence "generic")*/
+static void decodeGeneric(LodePNG_Decoder* decoder, unsigned char** out, size_t* outsize,
+ const unsigned char* in, size_t insize)
+{
+ unsigned char IEND = 0;
+ const unsigned char* chunk;
+ size_t i;
+ ucvector idat; /*the data from idat chunks*/
+
+ /*for unknown chunk order*/
+ unsigned unknown = 0;
+#ifdef LODEPNG_COMPILE_UNKNOWN_CHUNKS
+ unsigned critical_pos = 1; /*1 = after IHDR, 2 = after PLTE, 3 = after IDAT*/
+#endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/
+
+ /*provide some proper output values if error will happen*/
+ *out = 0;
+ *outsize = 0;
+
+ LodePNG_Decoder_inspect(decoder, in, insize); /*reads header and resets other parameters in decoder->infoPng*/
+ if(decoder->error) return;
+
+ ucvector_init(&idat);
+
+ chunk = &in[33]; /*first byte of the first chunk after the header*/
+
+ /*loop through the chunks, ignoring unknown chunks and stopping at IEND chunk.
+ IDAT data is put at the start of the in buffer*/
+ while(!IEND)
+ {
+ unsigned chunkLength;
+ const unsigned char* data; /*the data in the chunk*/
+
+ /*error: size of the in buffer too small to contain next chunk*/
+ if((size_t)((chunk - in) + 12) > insize || chunk < in) CERROR_BREAK(decoder->error, 30);
+
+ /*length of the data of the chunk, excluding the length bytes, chunk type and CRC bytes*/
+ chunkLength = LodePNG_chunk_length(chunk);
+ /*error: chunk length larger than the max PNG chunk size*/
+ if(chunkLength > 2147483647) CERROR_BREAK(decoder->error, 63);
+
+ if((size_t)((chunk - in) + chunkLength + 12) > insize || (chunk + chunkLength + 12) < in)
+ {
+ CERROR_BREAK(decoder->error, 64); /*error: size of the in buffer too small to contain next chunk*/
+ }
+
+ data = LodePNG_chunk_data_const(chunk);
+
+ /*IDAT chunk, containing compressed image data*/
+ if(LodePNG_chunk_type_equals(chunk, "IDAT"))
+ {
+ size_t oldsize = idat.size;
+ if(!ucvector_resize(&idat, oldsize + chunkLength)) CERROR_BREAK(decoder->error, 9936 /*alloc fail*/);
+ for(i = 0; i < chunkLength; i++) idat.data[oldsize + i] = data[i];
+#ifdef LODEPNG_COMPILE_UNKNOWN_CHUNKS
+ critical_pos = 3;
+#endif /*LODEPNG_COMPILE_UNKNOWN_CHUNKS*/
+ }
+ /*IEND chunk*/
+ else if(LodePNG_chunk_type_equals(chunk, "IEND"))
+ {
+ IEND = 1;
+ }
+ /*palette chunk (PLTE)*/
+ else if(LodePNG_chunk_type_equals(chunk, "PLTE"))
+ {
+ unsigned pos = 0;
+ if(decoder->infoPng.color.palette) free(decoder->infoPng.color.palette);
+ decoder->infoPng.color.palettesize = chunkLength / 3;
+ decoder->infoPng.color.palette = (unsigned char*)malloc(4 * decoder->infoPng.color.palettesize);
+ if(!decoder->infoPng.color.palette && decoder->infoPng.color.palettesize)
+ {
+ decoder->infoPng.color.palettesize = 0;
+ CERROR_BREAK(decoder->error, 9937); /*alloc fail*/
+ }
+ if(decoder->infoPng.color.palettesize > 256) CERROR_BREAK(decoder->error, 38); /*error: palette too big*/
+
+ for(i = 0; i < decoder->infoPng.color.palettesize; i++)
+ {
+ decoder->infoPng.color.palette[4 * i + 0] = data[pos++]; /*R*/
+ decoder->infoPng.color.palette[4 * i + 1] = data[pos++]; /*G*/
+ decoder->infoPng.color.palette[4 * i + 2] = data[pos++]; /*B*/
+ decoder->infoPng.color.palette[4 * i + 3] = 255; /*alpha*/
+ }
+#ifdef LODEPNG_COMPILE_UNKNOWN_CHUNKS
+ critical_pos = 2;
+#endif /*LODEPNG_COMPILE_UNKNOWN_CHUNKS*/
+ }
+ /*palette transparency chunk (tRNS)*/
+ else if(LodePNG_chunk_type_equals(chunk, "tRNS"))
+ {
+ if(decoder->infoPng.color.colorType == 3)
+ {
+ /*error: more alpha values given than there are palette entries*/
+ if(chunkLength > decoder->infoPng.color.palettesize) CERROR_BREAK(decoder->error, 38);
+
+ for(i = 0; i < chunkLength; i++) decoder->infoPng.color.palette[4 * i + 3] = data[i];
+ }
+ else if(decoder->infoPng.color.colorType == 0)
+ {
+ /*error: this chunk must be 2 bytes for greyscale image*/
+ if(chunkLength != 2) CERROR_BREAK(decoder->error, 30);
+
+ decoder->infoPng.color.key_defined = 1;
+ decoder->infoPng.color.key_r = decoder->infoPng.color.key_g
+ = decoder->infoPng.color.key_b = 256 * data[0] + data[1];
+ }
+ else if(decoder->infoPng.color.colorType == 2)
+ {
+ /*error: this chunk must be 6 bytes for RGB image*/
+ if(chunkLength != 6) CERROR_BREAK(decoder->error, 41);
+
+ decoder->infoPng.color.key_defined = 1;
+ decoder->infoPng.color.key_r = 256 * data[0] + data[1];
+ decoder->infoPng.color.key_g = 256 * data[2] + data[3];
+ decoder->infoPng.color.key_b = 256 * data[4] + data[5];
+ }
+ else CERROR_BREAK(decoder->error, 42); /*error: tRNS chunk not allowed for other color models*/
+ }
+#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS
+ /*background color chunk (bKGD)*/
+ else if(LodePNG_chunk_type_equals(chunk, "bKGD"))
+ {
+ if(decoder->infoPng.color.colorType == 3)
+ {
+ /*error: this chunk must be 1 byte for indexed color image*/
+ if(chunkLength != 1) CERROR_BREAK(decoder->error, 43);
+
+ decoder->infoPng.background_defined = 1;
+ decoder->infoPng.background_r = decoder->infoPng.background_g = decoder->infoPng.background_b = data[0];
+ }
+ else if(decoder->infoPng.color.colorType == 0 || decoder->infoPng.color.colorType == 4)
+ {
+ /*error: this chunk must be 2 bytes for greyscale image*/
+ if(chunkLength != 2) CERROR_BREAK(decoder->error, 44);
+
+ decoder->infoPng.background_defined = 1;
+ decoder->infoPng.background_r = decoder->infoPng.background_g = decoder->infoPng.background_b
+ = 256 * data[0] + data[1];
+ }
+ else if(decoder->infoPng.color.colorType == 2 || decoder->infoPng.color.colorType == 6)
+ {
+ /*error: this chunk must be 6 bytes for greyscale image*/
+ if(chunkLength != 6) CERROR_BREAK(decoder->error, 45);
+
+ decoder->infoPng.background_defined = 1;
+ decoder->infoPng.background_r = 256 * data[0] + data[1];
+ decoder->infoPng.background_g = 256 * data[2] + data[3];
+ decoder->infoPng.background_b = 256 * data[4] + data[5];
+ }
+ }
+ /*text chunk (tEXt)*/
+ else if(LodePNG_chunk_type_equals(chunk, "tEXt"))
+ {
+ if(decoder->settings.readTextChunks)
+ {
+ char *key = 0, *str = 0;
+
+ while(!decoder->error) /*not really a while loop, only used to break on error*/
+ {
+ unsigned length, string2_begin;
+
+ length = 0;
+ while(length < chunkLength && data[length] != 0) length++;
+ /*error, end reached, no null terminator?*/
+ if(length + 1 >= chunkLength) CERROR_BREAK(decoder->error, 75);
+
+ key = (char*)malloc(length + 1);
+ if(!key) CERROR_BREAK(decoder->error, 9938); /*alloc fail*/
+
+ key[length] = 0;
+ for(i = 0; i < length; i++) key[i] = data[i];
+
+ string2_begin = length + 1;
+ /*error, end reached, no null terminator?*/
+ if(string2_begin > chunkLength) CERROR_BREAK(decoder->error, 75);
+
+ length = chunkLength - string2_begin;
+ str = (char*)malloc(length + 1);
+ if(!str) CERROR_BREAK(decoder->error, 9939); /*alloc fail*/
+
+ str[length] = 0;
+ for(i = 0; i < length; i++) str[i] = data[string2_begin + i];
+
+ decoder->error = LodePNG_Text_add(&decoder->infoPng.text, key, str);
+
+ break;
+ }
+
+ free(key);
+ free(str);
+ }
+ }
+ /*compressed text chunk (zTXt)*/
+ else if(LodePNG_chunk_type_equals(chunk, "zTXt"))
+ {
+ if(decoder->settings.readTextChunks)
+ {
+ unsigned length, string2_begin;
+ char *key = 0;
+ ucvector decoded;
+
+ ucvector_init(&decoded);
+
+ while(!decoder->error) /*not really a while loop, only used to break on error*/
+ {
+ for(length = 0; length < chunkLength && data[length] != 0; length++) ;
+ if(length + 2 >= chunkLength) CERROR_BREAK(decoder->error, 75); /*no null termination, corrupt?*/
+
+ key = (char*)malloc(length + 1);
+ if(!key) CERROR_BREAK(decoder->error, 9940); /*alloc fail*/
+
+ key[length] = 0;
+ for(i = 0; i < length; i++) key[i] = data[i];
+
+ if(data[length + 1] != 0) CERROR_BREAK(decoder->error, 72); /*the 0 byte indicating compression must be 0*/
+
+ string2_begin = length + 2;
+ if(string2_begin > chunkLength) CERROR_BREAK(decoder->error, 75); /*no null termination, corrupt?*/
+
+ length = chunkLength - string2_begin;
+ decoder->error = LodePNG_zlib_decompress(&decoded.data, &decoded.size,
+ (unsigned char*)(&data[string2_begin]),
+ length, &decoder->settings.zlibsettings);
+ if(decoder->error) break;
+ ucvector_push_back(&decoded, 0);
+
+ decoder->error = LodePNG_Text_add(&decoder->infoPng.text, key, (char*)decoded.data);
+
+ break;
+ }
+
+ free(key);
+ ucvector_cleanup(&decoded);
+ if(decoder->error) break;
+ }
+ }
+ /*international text chunk (iTXt)*/
+ else if(LodePNG_chunk_type_equals(chunk, "iTXt"))
+ {
+ if(decoder->settings.readTextChunks)
+ {
+ unsigned length, begin, compressed;
+ char *key = 0, *langtag = 0, *transkey = 0;
+ ucvector decoded;
+ ucvector_init(&decoded);
+
+ while(!decoder->error) /*not really a while loop, only used to break on error*/
+ {
+ /*Quick check if the chunk length isn't too small. Even without check
+ it'd still fail with other error checks below if it's too short. This just gives a different error code.*/
+ if(chunkLength < 5) CERROR_BREAK(decoder->error, 30); /*iTXt chunk too short*/
+
+ /*read the key*/
+ for(length = 0; length < chunkLength && data[length] != 0; length++) ;
+ if(length + 2 >= chunkLength) CERROR_BREAK(decoder->error, 75); /*no null termination char found*/
+
+ key = (char*)malloc(length + 1);
+ if(!key) CERROR_BREAK(decoder->error, 9941); /*alloc fail*/
+
+ key[length] = 0;
+ for(i = 0; i < length; i++) key[i] = data[i];
+
+ /*read the compression method*/
+ compressed = data[length + 1];
+ if(data[length + 2] != 0) CERROR_BREAK(decoder->error, 72); /*the 0 byte indicating compression must be 0*/
+
+ /*read the langtag*/
+ begin = length + 3;
+ length = 0;
+ for(i = begin; i < chunkLength && data[i] != 0; i++) length++;
+ if(begin + length + 1 >= chunkLength) CERROR_BREAK(decoder->error, 75); /*no null termination char found*/
+
+ langtag = (char*)malloc(length + 1);
+ if(!langtag) CERROR_BREAK(decoder->error, 9942); /*alloc fail*/
+
+ langtag[length] = 0;
+ for(i = 0; i < length; i++) langtag[i] = data[begin + i];
+
+ /*read the transkey*/
+ begin += length + 1;
+ length = 0;
+ for(i = begin; i < chunkLength && data[i] != 0; i++) length++;
+ if(begin + length + 1 >= chunkLength) CERROR_BREAK(decoder->error, 75); /*no null termination, corrupt?*/
+
+ transkey = (char*)malloc(length + 1);
+ if(!transkey) CERROR_BREAK(decoder->error, 9943); /*alloc fail*/
+
+ transkey[length] = 0;
+ for(i = 0; i < length; i++) transkey[i] = data[begin + i];
+
+ /*read the actual text*/
+ begin += length + 1;
+ if(begin > chunkLength) CERROR_BREAK(decoder->error, 75); /*no null termination, corrupt?*/
+
+ length = chunkLength - begin;
+
+ if(compressed)
+ {
+ decoder->error = LodePNG_zlib_decompress(&decoded.data, &decoded.size,
+ (unsigned char*)(&data[begin]),
+ length, &decoder->settings.zlibsettings);
+ if(decoder->error) break;
+ ucvector_push_back(&decoded, 0);
+ }
+ else
+ {
+ if(!ucvector_resize(&decoded, length + 1)) CERROR_BREAK(decoder->error, 9944 /*alloc fail*/);
+
+ decoded.data[length] = 0;
+ for(i = 0; i < length; i++) decoded.data[i] = data[begin + i];
+ }
+
+ decoder->error = LodePNG_IText_add(&decoder->infoPng.itext, key, langtag, transkey, (char*)decoded.data);
+
+ break;
+ }
+
+ free(key);
+ free(langtag);
+ free(transkey);
+ ucvector_cleanup(&decoded);
+ if(decoder->error) break;
+ }
+ }
+ else if(LodePNG_chunk_type_equals(chunk, "tIME"))
+ {
+ if(chunkLength != 7) CERROR_BREAK(decoder->error, 73); /*invalid tIME chunk size*/
+
+ decoder->infoPng.time_defined = 1;
+ decoder->infoPng.time.year = 256 * data[0] + data[+ 1];
+ decoder->infoPng.time.month = data[2];
+ decoder->infoPng.time.day = data[3];
+ decoder->infoPng.time.hour = data[4];
+ decoder->infoPng.time.minute = data[5];
+ decoder->infoPng.time.second = data[6];
+ }
+ else if(LodePNG_chunk_type_equals(chunk, "pHYs"))
+ {
+ if(chunkLength != 9) CERROR_BREAK(decoder->error, 74); /*invalid pHYs chunk size*/
+
+ decoder->infoPng.phys_defined = 1;
+ decoder->infoPng.phys_x = 16777216 * data[0] + 65536 * data[1] + 256 * data[2] + data[3];
+ decoder->infoPng.phys_y = 16777216 * data[4] + 65536 * data[5] + 256 * data[6] + data[7];
+ decoder->infoPng.phys_unit = data[8];
+ }
+#endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/
+ else /*it's not an implemented chunk type, so ignore it: skip over the data*/
+ {
+ /*error: unknown critical chunk (5th bit of first byte of chunk type is 0)*/
+ if(LodePNG_chunk_critical(chunk)) CERROR_BREAK(decoder->error, 69);
+
+ unknown = 1;
+#ifdef LODEPNG_COMPILE_UNKNOWN_CHUNKS
+ if(decoder->settings.rememberUnknownChunks)
+ {
+ LodePNG_UnknownChunks* unknown = &decoder->infoPng.unknown_chunks;
+ decoder->error = LodePNG_append_chunk(&unknown->data[critical_pos - 1],
+ &unknown->datasize[critical_pos - 1], chunk);
+ if(decoder->error) break;
+ }
+#endif /*LODEPNG_COMPILE_UNKNOWN_CHUNKS*/
+ }
+
+ if(!decoder->settings.ignoreCrc && !unknown) /*check CRC if wanted, only on known chunk types*/
+ {
+ if(LodePNG_chunk_check_crc(chunk)) CERROR_BREAK(decoder->error, 57); /*invalid CRC*/
+ }
+
+ if(!IEND) chunk = LodePNG_chunk_next_const(chunk);
+ }
+
+ if(!decoder->error)
+ {
+ ucvector scanlines;
+ ucvector_init(&scanlines);
+
+ /*maximum final image length is already reserved in the vector's length - this is not really necessary*/
+ if(!ucvector_resize(&scanlines, ((decoder->infoPng.width * (decoder->infoPng.height
+ * LodePNG_InfoColor_getBpp(&decoder->infoPng.color) + 7)) / 8) + decoder->infoPng.height))
+ {
+ decoder->error = 9945; /*alloc fail*/
+ }
+ if(!decoder->error)
+ {
+ /*decompress with the Zlib decompressor*/
+ decoder->error = LodePNG_zlib_decompress(&scanlines.data, &scanlines.size, idat.data,
+ idat.size, &decoder->settings.zlibsettings);
+ }
+
+ if(!decoder->error)
+ {
+ ucvector outv;
+ ucvector_init(&outv);
+ if(!ucvector_resizev(&outv, (decoder->infoPng.height * decoder->infoPng.width
+ * LodePNG_InfoColor_getBpp(&decoder->infoPng.color) + 7) / 8, 0)) decoder->error = 9946; /*alloc fail*/
+ if(!decoder->error) decoder->error = postProcessScanlines(outv.data, scanlines.data, &decoder->infoPng);
+ *out = outv.data;
+ *outsize = outv.size;
+ }
+ ucvector_cleanup(&scanlines);
+ }
+
+ ucvector_cleanup(&idat);
+}
+
+void LodePNG_Decoder_decode(LodePNG_Decoder* decoder, unsigned char** out, size_t* outsize,
+ const unsigned char* in, size_t insize)
+{
+ *out = 0;
+ *outsize = 0;
+ decodeGeneric(decoder, out, outsize, in, insize);
+ if(decoder->error) return;
+ if(!decoder->settings.color_convert || LodePNG_InfoColor_equal(&decoder->infoRaw.color, &decoder->infoPng.color))
+ {
+ /*same color type, no copying or converting of data needed*/
+ /*store the infoPng color settings on the infoRaw so that the infoRaw still reflects what colorType
+ the raw image has to the end user*/
+ if(!decoder->settings.color_convert)
+ {
+ decoder->error = LodePNG_InfoColor_copy(&decoder->infoRaw.color, &decoder->infoPng.color);
+ if(decoder->error) return;
+ }
+ }
+ else
+ {
+ /*color conversion needed; sort of copy of the data*/
+ unsigned char* data = *out;
+
+ /*TODO: check if this works according to the statement in the documentation: "The converter can convert
+ from greyscale input color type, to 8-bit greyscale or greyscale with alpha"*/
+ if(!(decoder->infoRaw.color.colorType == 2 || decoder->infoRaw.color.colorType == 6)
+ && !(decoder->infoRaw.color.bitDepth == 8))
+ {
+ decoder->error = 56; /*unsupported color mode conversion*/
+ return;
+ }
+
+ *outsize = (decoder->infoPng.width * decoder->infoPng.height
+ * LodePNG_InfoColor_getBpp(&decoder->infoRaw.color) + 7) / 8;
+ *out = (unsigned char*)malloc(*outsize);
+ if(!(*out))
+ {
+ decoder->error = 9947; /*alloc fail*/
+ *outsize = 0;
+ }
+ else decoder->error = LodePNG_convert(*out, data, &decoder->infoRaw.color, &decoder->infoPng.color,
+ decoder->infoPng.width, decoder->infoPng.height);
+ free(data);
+ }
+}
+
+unsigned LodePNG_decode(unsigned char** out, unsigned* w, unsigned* h, const unsigned char* in,
+ size_t insize, unsigned colorType, unsigned bitDepth)
+{
+ unsigned error;
+ size_t dummy_size;
+ LodePNG_Decoder decoder;
+ LodePNG_Decoder_init(&decoder);
+ decoder.infoRaw.color.colorType = colorType;
+ decoder.infoRaw.color.bitDepth = bitDepth;
+ LodePNG_Decoder_decode(&decoder, out, &dummy_size, in, insize);
+ error = decoder.error;
+ *w = decoder.infoPng.width;
+ *h = decoder.infoPng.height;
+ LodePNG_Decoder_cleanup(&decoder);
+ return error;
+}
+
+unsigned LodePNG_decode32(unsigned char** out, unsigned* w, unsigned* h, const unsigned char* in, size_t insize)
+{
+ return LodePNG_decode(out, w, h, in, insize, 6, 8);
+}
+
+unsigned LodePNG_decode24(unsigned char** out, unsigned* w, unsigned* h, const unsigned char* in, size_t insize)
+{
+ return LodePNG_decode(out, w, h, in, insize, 2, 8);
+}
+
+#ifdef LODEPNG_COMPILE_DISK
+unsigned LodePNG_decode_file(unsigned char** out, unsigned* w, unsigned* h, const char* filename,
+ unsigned colorType, unsigned bitDepth)
+{
+ unsigned char* buffer;
+ size_t buffersize;
+ unsigned error;
+ error = LodePNG_loadFile(&buffer, &buffersize, filename);
+ if(!error) error = LodePNG_decode(out, w, h, buffer, buffersize, colorType, bitDepth);
+ free(buffer);
+ return error;
+}
+
+unsigned LodePNG_decode32_file(unsigned char** out, unsigned* w, unsigned* h, const char* filename)
+{
+ return LodePNG_decode_file(out, w, h, filename, 6, 8);
+}
+
+unsigned LodePNG_decode24_file(unsigned char** out, unsigned* w, unsigned* h, const char* filename)
+{
+ return LodePNG_decode_file(out, w, h, filename, 2, 8);
+}
+#endif /*LODEPNG_COMPILE_DISK*/
+
+void LodePNG_DecodeSettings_init(LodePNG_DecodeSettings* settings)
+{
+ settings->color_convert = 1;
+#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS
+ settings->readTextChunks = 1;
+#endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/
+ settings->ignoreCrc = 0;
+#ifdef LODEPNG_COMPILE_UNKNOWN_CHUNKS
+ settings->rememberUnknownChunks = 0;
+#endif /*LODEPNG_COMPILE_UNKNOWN_CHUNKS*/
+ LodePNG_DecompressSettings_init(&settings->zlibsettings);
+}
+
+void LodePNG_Decoder_init(LodePNG_Decoder* decoder)
+{
+ LodePNG_DecodeSettings_init(&decoder->settings);
+ LodePNG_InfoRaw_init(&decoder->infoRaw);
+ LodePNG_InfoPng_init(&decoder->infoPng);
+ decoder->error = 1;
+}
+
+void LodePNG_Decoder_cleanup(LodePNG_Decoder* decoder)
+{
+ LodePNG_InfoRaw_cleanup(&decoder->infoRaw);
+ LodePNG_InfoPng_cleanup(&decoder->infoPng);
+}
+
+void LodePNG_Decoder_copy(LodePNG_Decoder* dest, const LodePNG_Decoder* source)
+{
+ LodePNG_Decoder_cleanup(dest);
+ *dest = *source;
+ LodePNG_InfoRaw_init(&dest->infoRaw);
+ LodePNG_InfoPng_init(&dest->infoPng);
+ dest->error = LodePNG_InfoRaw_copy(&dest->infoRaw, &source->infoRaw); if(dest->error) return;
+ dest->error = LodePNG_InfoPng_copy(&dest->infoPng, &source->infoPng); if(dest->error) return;
+}
+
+#endif /*LODEPNG_COMPILE_DECODER*/
+
+#ifdef LODEPNG_COMPILE_ENCODER
+
+/* ////////////////////////////////////////////////////////////////////////// */
+/* / PNG Encoder / */
+/* ////////////////////////////////////////////////////////////////////////// */
+
+/*chunkName must be string of 4 characters*/
+static unsigned addChunk(ucvector* out, const char* chunkName, const unsigned char* data, size_t length)
+{
+ unsigned error = LodePNG_create_chunk(&out->data, &out->size, (unsigned)length, chunkName, data);
+ if(error) return error;
+ out->allocsize = out->size; /*fix the allocsize again*/
+ return 0;
+}
+
+static void writeSignature(ucvector* out)
+{
+ /*8 bytes PNG signature, aka the magic bytes*/
+ ucvector_push_back(out, 137);
+ ucvector_push_back(out, 80);
+ ucvector_push_back(out, 78);
+ ucvector_push_back(out, 71);
+ ucvector_push_back(out, 13);
+ ucvector_push_back(out, 10);
+ ucvector_push_back(out, 26);
+ ucvector_push_back(out, 10);
+}
+
+static unsigned addChunk_IHDR(ucvector* out, unsigned w, unsigned h, unsigned bitDepth,
+ unsigned colorType, unsigned interlaceMethod)
+{
+ unsigned error = 0;
+ ucvector header;
+ ucvector_init(&header);
+
+ LodePNG_add32bitInt(&header, w); /*width*/
+ LodePNG_add32bitInt(&header, h); /*height*/
+ ucvector_push_back(&header, (unsigned char)bitDepth); /*bit depth*/
+ ucvector_push_back(&header, (unsigned char)colorType); /*color type*/
+ ucvector_push_back(&header, 0); /*compression method*/
+ ucvector_push_back(&header, 0); /*filter method*/
+ ucvector_push_back(&header, interlaceMethod); /*interlace method*/
+
+ error = addChunk(out, "IHDR", header.data, header.size);
+ ucvector_cleanup(&header);
+
+ return error;
+}
+
+static unsigned addChunk_PLTE(ucvector* out, const LodePNG_InfoColor* info)
+{
+ unsigned error = 0;
+ size_t i;
+ ucvector PLTE;
+ ucvector_init(&PLTE);
+ for(i = 0; i < info->palettesize * 4; i++)
+ {
+ /*add all channels except alpha channel*/
+ if(i % 4 != 3) ucvector_push_back(&PLTE, info->palette[i]);
+ }
+ error = addChunk(out, "PLTE", PLTE.data, PLTE.size);
+ ucvector_cleanup(&PLTE);
+
+ return error;
+}
+
+static unsigned addChunk_tRNS(ucvector* out, const LodePNG_InfoColor* info)
+{
+ unsigned error = 0;
+ size_t i;
+ ucvector tRNS;
+ ucvector_init(&tRNS);
+ if(info->colorType == 3)
+ {
+ /*add only alpha channel*/
+ for(i = 0; i < info->palettesize; i++) ucvector_push_back(&tRNS, info->palette[4 * i + 3]);
+ }
+ else if(info->colorType == 0)
+ {
+ if(info->key_defined)
+ {
+ ucvector_push_back(&tRNS, (unsigned char)(info->key_r / 256));
+ ucvector_push_back(&tRNS, (unsigned char)(info->key_r % 256));
+ }
+ }
+ else if(info->colorType == 2)
+ {
+ if(info->key_defined)
+ {
+ ucvector_push_back(&tRNS, (unsigned char)(info->key_r / 256));
+ ucvector_push_back(&tRNS, (unsigned char)(info->key_r % 256));
+ ucvector_push_back(&tRNS, (unsigned char)(info->key_g / 256));
+ ucvector_push_back(&tRNS, (unsigned char)(info->key_g % 256));
+ ucvector_push_back(&tRNS, (unsigned char)(info->key_b / 256));
+ ucvector_push_back(&tRNS, (unsigned char)(info->key_b % 256));
+ }
+ }
+
+ error = addChunk(out, "tRNS", tRNS.data, tRNS.size);
+ ucvector_cleanup(&tRNS);
+
+ return error;
+}
+
+static unsigned addChunk_IDAT(ucvector* out, const unsigned char* data, size_t datasize,
+ LodePNG_CompressSettings* zlibsettings)
+{
+ ucvector zlibdata;
+ unsigned error = 0;
+
+ /*compress with the Zlib compressor*/
+ ucvector_init(&zlibdata);
+ error = LodePNG_zlib_compress(&zlibdata.data, &zlibdata.size, data, datasize, zlibsettings);
+ if(!error) error = addChunk(out, "IDAT", zlibdata.data, zlibdata.size);
+ ucvector_cleanup(&zlibdata);
+
+ return error;
+}
+
+static unsigned addChunk_IEND(ucvector* out)
+{
+ unsigned error = 0;
+ error = addChunk(out, "IEND", 0, 0);
+ return error;
+}
+
+#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS
+
+static unsigned addChunk_tEXt(ucvector* out, const char* keyword, const char* textstring)
+{
+ unsigned error = 0;
+ size_t i;
+ ucvector text;
+ ucvector_init(&text);
+ for(i = 0; keyword[i] != 0; i++) ucvector_push_back(&text, (unsigned char)keyword[i]);
+ ucvector_push_back(&text, 0);
+ for(i = 0; textstring[i] != 0; i++) ucvector_push_back(&text, (unsigned char)textstring[i]);
+ error = addChunk(out, "tEXt", text.data, text.size);
+ ucvector_cleanup(&text);
+
+ return error;
+}
+
+static unsigned addChunk_zTXt(ucvector* out, const char* keyword, const char* textstring,
+ LodePNG_CompressSettings* zlibsettings)
+{
+ unsigned error = 0;
+ ucvector data, compressed;
+ size_t i, textsize = strlen(textstring);
+
+ ucvector_init(&data);
+ ucvector_init(&compressed);
+ for(i = 0; keyword[i] != 0; i++) ucvector_push_back(&data, (unsigned char)keyword[i]);
+ ucvector_push_back(&data, 0); /* 0 termination char*/
+ ucvector_push_back(&data, 0); /*compression method: 0*/
+
+ error = LodePNG_zlib_compress(&compressed.data, &compressed.size,
+ (unsigned char*)textstring, textsize, zlibsettings);
+ if(!error)
+ {
+ for(i = 0; i < compressed.size; i++) ucvector_push_back(&data, compressed.data[i]);
+ error = addChunk(out, "zTXt", data.data, data.size);
+ }
+
+ ucvector_cleanup(&compressed);
+ ucvector_cleanup(&data);
+ return error;
+}
+
+static unsigned addChunk_iTXt(ucvector* out, unsigned compressed, const char* keyword, const char* langtag,
+ const char* transkey, const char* textstring, LodePNG_CompressSettings* zlibsettings)
+{
+ unsigned error = 0;
+ ucvector data, compressed_data;
+ size_t i, textsize = strlen(textstring);
+
+ ucvector_init(&data);
+
+ for(i = 0; keyword[i] != 0; i++) ucvector_push_back(&data, (unsigned char)keyword[i]);
+ ucvector_push_back(&data, 0); /*null termination char*/
+ ucvector_push_back(&data, compressed ? 1 : 0); /*compression flag*/
+ ucvector_push_back(&data, 0); /*compression method*/
+ for(i = 0; langtag[i] != 0; i++) ucvector_push_back(&data, (unsigned char)langtag[i]);
+ ucvector_push_back(&data, 0); /*null termination char*/
+ for(i = 0; transkey[i] != 0; i++) ucvector_push_back(&data, (unsigned char)transkey[i]);
+ ucvector_push_back(&data, 0); /*null termination char*/
+
+ if(compressed)
+ {
+ ucvector_init(&compressed_data);
+ error = LodePNG_zlib_compress(&compressed_data.data, &compressed_data.size,
+ (unsigned char*)textstring, textsize, zlibsettings);
+ if(!error)
+ {
+ for(i = 0; i < compressed_data.size; i++) ucvector_push_back(&data, compressed_data.data[i]);
+ for(i = 0; textstring[i] != 0; i++) ucvector_push_back(&data, (unsigned char)textstring[i]);
+ }
+ }
+ else /*not compressed*/
+ {
+ for(i = 0; textstring[i] != 0; i++) ucvector_push_back(&data, (unsigned char)textstring[i]);
+ }
+
+ if(!error) error = addChunk(out, "iTXt", data.data, data.size);
+ ucvector_cleanup(&data);
+ return error;
+}
+
+static unsigned addChunk_bKGD(ucvector* out, const LodePNG_InfoPng* info)
+{
+ unsigned error = 0;
+ ucvector bKGD;
+ ucvector_init(&bKGD);
+ if(info->color.colorType == 0 || info->color.colorType == 4)
+ {
+ ucvector_push_back(&bKGD, (unsigned char)(info->background_r / 256));
+ ucvector_push_back(&bKGD, (unsigned char)(info->background_r % 256));
+ }
+ else if(info->color.colorType == 2 || info->color.colorType == 6)
+ {
+ ucvector_push_back(&bKGD, (unsigned char)(info->background_r / 256));
+ ucvector_push_back(&bKGD, (unsigned char)(info->background_r % 256));
+ ucvector_push_back(&bKGD, (unsigned char)(info->background_g / 256));
+ ucvector_push_back(&bKGD, (unsigned char)(info->background_g % 256));
+ ucvector_push_back(&bKGD, (unsigned char)(info->background_b / 256));
+ ucvector_push_back(&bKGD, (unsigned char)(info->background_b % 256));
+ }
+ else if(info->color.colorType == 3)
+ {
+ ucvector_push_back(&bKGD, (unsigned char)(info->background_r % 256)); /*palette index*/
+ }
+
+ error = addChunk(out, "bKGD", bKGD.data, bKGD.size);
+ ucvector_cleanup(&bKGD);
+
+ return error;
+}
+
+static unsigned addChunk_tIME(ucvector* out, const LodePNG_Time* time)
+{
+ unsigned error = 0;
+ unsigned char* data = (unsigned char*)malloc(7);
+ if(!data) return 9948; /*alloc fail*/
+ data[0] = (unsigned char)(time->year / 256);
+ data[1] = (unsigned char)(time->year % 256);
+ data[2] = time->month;
+ data[3] = time->day;
+ data[4] = time->hour;
+ data[5] = time->minute;
+ data[6] = time->second;
+ error = addChunk(out, "tIME", data, 7);
+ free(data);
+ return error;
+}
+
+static unsigned addChunk_pHYs(ucvector* out, const LodePNG_InfoPng* info)
+{
+ unsigned error = 0;
+ ucvector data;
+ ucvector_init(&data);
+
+ LodePNG_add32bitInt(&data, info->phys_x);
+ LodePNG_add32bitInt(&data, info->phys_y);
+ ucvector_push_back(&data, info->phys_unit);
+
+ error = addChunk(out, "pHYs", data.data, data.size);
+ ucvector_cleanup(&data);
+
+ return error;
+}
+
+#endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/
+
+static void filterScanline(unsigned char* out, const unsigned char* scanline, const unsigned char* prevline,
+ size_t length, size_t bytewidth, unsigned char filterType)
+{
+ size_t i;
+ switch(filterType)
+ {
+ case 0: /*None*/
+ for(i = 0; i < length; i++) out[i] = scanline[i];
+ break;
+ case 1: /*Sub*/
+ if(prevline)
+ {
+ for(i = 0; i < bytewidth; i++) out[i] = scanline[i];
+ for(i = bytewidth; i < length ; i++) out[i] = scanline[i] - scanline[i - bytewidth];
+ }
+ else
+ {
+ for(i = 0; i < bytewidth; i++) out[i] = scanline[i];
+ for(i = bytewidth; i < length; i++) out[i] = scanline[i] - scanline[i - bytewidth];
+ }
+ break;
+ case 2: /*Up*/
+ if(prevline)
+ {
+ for(i = 0; i < length; i++) out[i] = scanline[i] - prevline[i];
+ }
+ else
+ {
+ for(i = 0; i < length; i++) out[i] = scanline[i];
+ }
+ break;
+ case 3: /*Average*/
+ if(prevline)
+ {
+ for(i = 0; i < bytewidth; i++) out[i] = scanline[i] - prevline[i] / 2;
+ for(i = bytewidth; i < length; i++) out[i] = scanline[i] - ((scanline[i - bytewidth] + prevline[i]) / 2);
+ }
+ else
+ {
+ for(i = 0; i < bytewidth; i++) out[i] = scanline[i];
+ for(i = bytewidth; i < length; i++) out[i] = scanline[i] - scanline[i - bytewidth] / 2;
+ }
+ break;
+ case 4: /*Paeth*/
+ if(prevline)
+ {
+ /*paethPredictor(0, prevline[i], 0) is always prevline[i]*/
+ for(i = 0; i < bytewidth; i++) out[i] = (scanline[i] - prevline[i]);
+ for(i = bytewidth; i < length; i++)
+ {
+ out[i] = (scanline[i] - paethPredictor(scanline[i - bytewidth], prevline[i], prevline[i - bytewidth]));
+ }
+ }
+ else
+ {
+ for(i = 0; i < bytewidth; i++) out[i] = scanline[i];
+ /*paethPredictor(scanline[i - bytewidth], 0, 0) is always scanline[i - bytewidth]*/
+ for(i = bytewidth; i < length; i++) out[i] = (scanline[i] - scanline[i - bytewidth]);
+ }
+ break;
+ default: return; /*unexisting filter type given*/
+ }
+}
+
+static unsigned filter(unsigned char* out, const unsigned char* in, unsigned w, unsigned h,
+ const LodePNG_InfoColor* info, const LodePNG_EncodeSettings* settings)
+{
+ /*
+ For PNG filter method 0
+ out must be a buffer with as size: h + (w * h * bpp + 7) / 8, because there are
+ the scanlines with 1 extra byte per scanline
+ */
+
+ unsigned bpp = LodePNG_InfoColor_getBpp(info);
+ /*the width of a scanline in bytes, not including the filter type*/
+ size_t linebytes = (w * bpp + 7) / 8;
+ /*bytewidth is used for filtering, is 1 when bpp < 8, number of bytes per pixel otherwise*/
+ size_t bytewidth = (bpp + 7) / 8;
+ const unsigned char* prevline = 0;
+ unsigned x, y;
+ unsigned error = 0;
+
+ if(bpp == 0) return 31; /*error: invalid color type*/
+
+ if(!settings->bruteForceFilters)
+ {
+ /*
+ There is a heuristic called the minimum sum of absolute differences heuristic, suggested by the PNG standard:
+ * If the image type is Palette, or the bit depth is smaller than 8, then do not filter the image (i.e.
+ use fixed filtering, with the filter None).
+ * (The other case) If the image type is Grayscale or RGB (with or without Alpha), and the bit depth is
+ not smaller than 8, then use adaptive filtering heuristic as follows: independently for each row, apply
+ all five filters and select the filter that produces the smallest sum of absolute values per row.
+ */
+ if(info->colorType == 3 || info->bitDepth < 8) /*None filtertype for everything*/
+ {
+ for(y = 0; y < h; y++)
+ {
+ size_t outindex = (1 + linebytes) * y; /*the extra filterbyte added to each row*/
+ size_t inindex = linebytes * y;
+ const unsigned TYPE = 0;
+ out[outindex] = TYPE; /*filter type byte*/
+ filterScanline(&out[outindex + 1], &in[inindex], prevline, linebytes, bytewidth, TYPE);
+ prevline = &in[inindex];
+ }
+ }
+ else /*adaptive filtering*/
+ {
+ size_t sum[5];
+ ucvector attempt[5]; /*five filtering attempts, one for each filter type*/
+ size_t smallest = 0;
+ unsigned type, bestType = 0;
+
+ for(type = 0; type < 5; type++) ucvector_init(&attempt[type]);
+ for(type = 0; type < 5; type++)
+ {
+ if(!ucvector_resize(&attempt[type], linebytes)) ERROR_BREAK(9949 /*alloc fail*/);
+ }
+
+ if(!error)
+ {
+ for(y = 0; y < h; y++)
+ {
+ /*try the 5 filter types*/
+ for(type = 0; type < 5; type++)
+ {
+ filterScanline(attempt[type].data, &in[y * linebytes], prevline, linebytes, bytewidth, type);
+
+ /*calculate the sum of the result*/
+ sum[type] = 0;
+ /*note that not all pixels are checked to speed this up while still having probably the best choice*/
+ for(x = 0; x < attempt[type].size; x+=3)
+ {
+ /*For differences, each byte should be treated as signed, values above 127 are negative
+ (converted to signed char). Filtertype 0 isn't a difference though, so use unsigned there.
+ This means filtertype 0 is almost never chosen, but that is justified.*/
+ if(type == 0) sum[type] += (unsigned char)(attempt[type].data[x]);
+ else
+ {
+ signed char s = (signed char)(attempt[type].data[x]);
+ sum[type] += s < 0 ? -s : s;
+ }
+ }
+
+ /*check if this is smallest sum (or if type == 0 it's the first case so always store the values)*/
+ if(type == 0 || sum[type] < smallest)
+ {
+ bestType = type;
+ smallest = sum[type];
+ }
+ }
+
+ prevline = &in[y * linebytes];
+
+ /*now fill the out values*/
+ out[y * (linebytes + 1)] = bestType; /*the first byte of a scanline will be the filter type*/
+ for(x = 0; x < linebytes; x++) out[y * (linebytes + 1) + 1 + x] = attempt[bestType].data[x];
+ }
+ }
+
+ for(type = 0; type < 5; type++) ucvector_cleanup(&attempt[type]);
+ }
+ }
+ else
+ {
+ /*brute force filter chooser.
+ deflate the scanline after every filter attempt to see which one deflates best.
+ This is very slow and gives only slightly smaller, sometimes even larger, result*/
+ size_t size[5];
+ ucvector attempt[5]; /*five filtering attempts, one for each filter type*/
+ size_t smallest;
+ unsigned type = 0, bestType = 0;
+ unsigned char* dummy;
+ LodePNG_CompressSettings zlibsettings = settings->zlibsettings;
+ /*use fixed tree on the attempts so that the tree is not adapted to the filtertype on purpose,
+ to simulate the true case where the tree is the same for the whole image. Sometimes it gives
+ better result with dynamic tree anyway. Using the fixed tree sometimes gives worse, but in rare
+ cases better compression. It does make this a bit less slow, so it's worth doing this.*/
+ zlibsettings.btype = 1;
+ for(type = 0; type < 5; type++)
+ {
+ ucvector_init(&attempt[type]);
+ ucvector_resize(&attempt[type], linebytes); /*todo: give error if resize failed*/
+ }
+ for(y = 0; y < h; y++) /*try the 5 filter types*/
+ {
+ for(type = 0; type < 5; type++)
+ {
+ unsigned testsize = attempt[type].size;
+ /*unsigned testsize = attempt[type].size / 8;*/ /*it already works good enough by testing a part of the row*/
+ /*if(testsize == 0) testsize = attempt[type].size;*/
+
+ filterScanline(attempt[type].data, &in[y * linebytes], prevline, linebytes, bytewidth, type);
+ size[type] = 0;
+ dummy = 0;
+ LodePNG_zlib_compress(&dummy, &size[type], attempt[type].data, testsize, &zlibsettings);
+ free(dummy);
+ /*check if this is smallest size (or if type == 0 it's the first case so always store the values)*/
+ if(type == 0 || size[type] < smallest)
+ {
+ bestType = type;
+ smallest = size[type];
+ }
+ }
+ prevline = &in[y * linebytes];
+ out[y * (linebytes + 1)] = bestType; /*the first byte of a scanline will be the filter type*/
+ for(x = 0; x < linebytes; x++) out[y * (linebytes + 1) + 1 + x] = attempt[bestType].data[x];
+ }
+ for(type = 0; type < 5; type++) ucvector_cleanup(&attempt[type]);
+ }
+
+ return error;
+}
+
+static void addPaddingBits(unsigned char* out, const unsigned char* in,
+ size_t olinebits, size_t ilinebits, unsigned h)
+{
+ /*The opposite of the removePaddingBits function
+ olinebits must be >= ilinebits*/
+ unsigned y;
+ size_t diff = olinebits - ilinebits;
+ size_t obp = 0, ibp = 0; /*bit pointers*/
+ for(y = 0; y < h; y++)
+ {
+ size_t x;
+ for(x = 0; x < ilinebits; x++)
+ {
+ unsigned char bit = readBitFromReversedStream(&ibp, in);
+ setBitOfReversedStream(&obp, out, bit);
+ }
+ /*obp += diff; --> no, fill in some value in the padding bits too, to avoid
+ "Use of uninitialised value of size ###" warning from valgrind*/
+ for(x = 0; x < diff; x++) setBitOfReversedStream(&obp, out, 0);
+ }
+}
+
+static void Adam7_interlace(unsigned char* out, const unsigned char* in, unsigned w, unsigned h, unsigned bpp)
+{
+ /*Note: this function works on image buffers WITHOUT padding bits at end of scanlines with non-multiple-of-8
+ bit amounts, only between reduced images is padding*/
+ unsigned passw[7], passh[7];
+ size_t filter_passstart[8], padded_passstart[8], passstart[8];
+ unsigned i;
+
+ Adam7_getpassvalues(passw, passh, filter_passstart, padded_passstart, passstart, w, h, bpp);
+
+ if(bpp >= 8)
+ {
+ for(i = 0; i < 7; i++)
+ {
+ unsigned x, y, b;
+ size_t bytewidth = bpp / 8;
+ for(y = 0; y < passh[i]; y++)
+ for(x = 0; x < passw[i]; x++)
+ {
+ size_t pixelinstart = ((ADAM7_IY[i] + y * ADAM7_DY[i]) * w + ADAM7_IX[i] + x * ADAM7_DX[i]) * bytewidth;
+ size_t pixeloutstart = passstart[i] + (y * passw[i] + x) * bytewidth;
+ for(b = 0; b < bytewidth; b++)
+ {
+ out[pixeloutstart + b] = in[pixelinstart + b];
+ }
+ }
+ }
+ }
+ else /*bpp < 8: Adam7 with pixels < 8 bit is a bit trickier: with bit pointers*/
+ {
+ for(i = 0; i < 7; i++)
+ {
+ unsigned x, y, b;
+ unsigned ilinebits = bpp * passw[i];
+ unsigned olinebits = bpp * w;
+ size_t obp, ibp; /*bit pointers (for out and in buffer)*/
+ for(y = 0; y < passh[i]; y++)
+ for(x = 0; x < passw[i]; x++)
+ {
+ ibp = (ADAM7_IY[i] + y * ADAM7_DY[i]) * olinebits + (ADAM7_IX[i] + x * ADAM7_DX[i]) * bpp;
+ obp = (8 * passstart[i]) + (y * ilinebits + x * bpp);
+ for(b = 0; b < bpp; b++)
+ {
+ unsigned char bit = readBitFromReversedStream(&ibp, in);
+ setBitOfReversedStream(&obp, out, bit);
+ }
+ }
+ }
+ }
+}
+
+/*out must be buffer big enough to contain uncompressed IDAT chunk data, and in must contain the full image.
+return value is error**/
+static unsigned preProcessScanlines(unsigned char** out, size_t* outsize, const unsigned char* in,
+ const LodePNG_InfoPng* infoPng, const LodePNG_EncodeSettings* settings)
+{
+ /*
+ This function converts the pure 2D image with the PNG's colortype, into filtered-padded-interlaced data. Steps:
+ *) if no Adam7: 1) add padding bits (= posible extra bits per scanline if bpp < 8) 2) filter
+ *) if adam7: 1) Adam7_interlace 2) 7x add padding bits 3) 7x filter
+ */
+ unsigned bpp = LodePNG_InfoColor_getBpp(&infoPng->color);
+ unsigned w = infoPng->width;
+ unsigned h = infoPng->height;
+ unsigned error = 0;
+
+ if(infoPng->interlaceMethod == 0)
+ {
+ *outsize = h + (h * ((w * bpp + 7) / 8)); /*image size plus an extra byte per scanline + possible padding bits*/
+ *out = (unsigned char*)malloc(*outsize);
+ if(!(*out) && (*outsize)) error = 9950; /*alloc fail*/
+
+ if(!error)
+ {
+ /*non multiple of 8 bits per scanline, padding bits needed per scanline*/
+ if(bpp < 8 && w * bpp != ((w * bpp + 7) / 8) * 8)
+ {
+ ucvector padded;
+ ucvector_init(&padded);
+ if(!ucvector_resize(&padded, h * ((w * bpp + 7) / 8))) error = 9951; /*alloc fail*/
+ if(!error)
+ {
+ addPaddingBits(padded.data, in, ((w * bpp + 7) / 8) * 8, w * bpp, h);
+ error = filter(*out, padded.data, w, h, &infoPng->color, settings);
+ }
+ ucvector_cleanup(&padded);
+ }
+ else
+ {
+ /*we can immediatly filter into the out buffer, no other steps needed*/
+ error = filter(*out, in, w, h, &infoPng->color, settings);
+ }
+ }
+ }
+ else /*interlaceMethod is 1 (Adam7)*/
+ {
+ unsigned char* adam7 = (unsigned char*)malloc((h * w * bpp + 7) / 8);
+ if(!adam7 && ((h * w * bpp + 7) / 8)) error = 9952; /*alloc fail*/
+
+ while(!error) /*not a real while loop, used to break out to cleanup to avoid a goto*/
+ {
+ unsigned passw[7], passh[7];
+ size_t filter_passstart[8], padded_passstart[8], passstart[8];
+ unsigned i;
+
+ Adam7_getpassvalues(passw, passh, filter_passstart, padded_passstart, passstart, w, h, bpp);
+
+ *outsize = filter_passstart[7]; /*image size plus an extra byte per scanline + possible padding bits*/
+ *out = (unsigned char*)malloc(*outsize);
+ if(!(*out) && (*outsize)) ERROR_BREAK(9953 /*alloc fail*/);
+
+ Adam7_interlace(adam7, in, w, h, bpp);
+
+ for(i = 0; i < 7; i++)
+ {
+ if(bpp < 8)
+ {
+ ucvector padded;
+ ucvector_init(&padded);
+ if(!ucvector_resize(&padded, h * ((w * bpp + 7) / 8))) error = 9954; /*alloc fail*/
+ if(!error)
+ {
+ addPaddingBits(&padded.data[padded_passstart[i]], &adam7[passstart[i]],
+ ((passw[i] * bpp + 7) / 8) * 8, passw[i] * bpp, passh[i]);
+ error = filter(&(*out)[filter_passstart[i]], &padded.data[padded_passstart[i]],
+ passw[i], passh[i], &infoPng->color, settings);
+ }
+
+ ucvector_cleanup(&padded);
+ }
+ else
+ {
+ error = filter(&(*out)[filter_passstart[i]], &adam7[padded_passstart[i]],
+ passw[i], passh[i], &infoPng->color, settings);
+ }
+ }
+
+ break;
+ }
+
+ free(adam7);
+ }
+
+ return error;
+}
+
+/*palette must have 4 * palettesize bytes allocated, and given in format RGBARGBARGBARGBA...*/
+static unsigned isPaletteFullyOpaque(const unsigned char* palette, size_t palettesize)
+{
+ size_t i;
+ for(i = 0; i < palettesize; i++)
+ {
+ if(palette[4 * i + 3] != 255) return 0;
+ }
+ return 1;
+}
+
+/*this function checks if the input image given by the user has no transparent pixels*/
+static unsigned isFullyOpaque(const unsigned char* image, unsigned w, unsigned h, const LodePNG_InfoColor* info)
+{
+ /*TODO: When the user specified a color key for the input image, then this function must
+ also check for pixels that are the same as the color key and treat those as transparent.*/
+
+ unsigned i, numpixels = w * h;
+ if(info->colorType == 6)
+ {
+ if(info->bitDepth == 8)
+ {
+ for(i = 0; i < numpixels; i++)
+ {
+ if(image[i * 4 + 3] != 255) return 0;
+ }
+ }
+ else
+ {
+ for(i = 0; i < numpixels; i++)
+ {
+ if(image[i * 8 + 6] != 255 || image[i * 8 + 7] != 255) return 0;
+ }
+ }
+ return 1; /*no single pixel with alpha channel other than 255 found*/
+ }
+ else if(info->colorType == 4)
+ {
+ if(info->bitDepth == 8)
+ {
+ for(i = 0; i < numpixels; i++)
+ {
+ if(image[i * 2 + 1] != 255) return 0;
+ }
+ }
+ else
+ {
+ for(i = 0; i < numpixels; i++)
+ {
+ if(image[i * 4 + 2] != 255 || image[i * 4 + 3] != 255) return 0;
+ }
+ }
+ return 1; /*no single pixel with alpha channel other than 255 found*/
+ }
+ else if(info->colorType == 3)
+ {
+ /*when there's a palette, we could check every pixel for translucency,
+ but much quicker is to just check the palette*/
+ return(isPaletteFullyOpaque(info->palette, info->palettesize));
+ }
+
+ return 0; /*color type that isn't supported by this function yet, so assume there is transparency to be safe*/
+}
+
+#ifdef LODEPNG_COMPILE_UNKNOWN_CHUNKS
+static unsigned addUnknownChunks(ucvector* out, unsigned char* data, size_t datasize)
+{
+ unsigned char* inchunk = data;
+ while((size_t)(inchunk - data) < datasize)
+ {
+ unsigned error = LodePNG_append_chunk(&out->data, &out->size, inchunk);
+ if(error) return error; /*error: not enough memory*/
+ out->allocsize = out->size; /*fix the allocsize again*/
+ inchunk = LodePNG_chunk_next(inchunk);
+ }
+ return 0;
+}
+#endif /*LODEPNG_COMPILE_UNKNOWN_CHUNKS*/
+
+void LodePNG_Encoder_encode(LodePNG_Encoder* encoder, unsigned char** out, size_t* outsize,
+ const unsigned char* image, unsigned w, unsigned h)
+{
+ LodePNG_InfoPng info;
+ ucvector outv;
+ unsigned char* data = 0; /*uncompressed version of the IDAT chunk data*/
+ size_t datasize = 0;
+
+ /*provide some proper output values if error will happen*/
+ *out = 0;
+ *outsize = 0;
+ encoder->error = 0;
+
+ /*UNSAFE copy to avoid having to cleanup! but we will only change primitive parameters,
+ and not invoke the cleanup function nor touch the palette's buffer so we use it safely*/
+ info = encoder->infoPng;
+ info.width = w;
+ info.height = h;
+
+ if(encoder->settings.autoLeaveOutAlphaChannel && isFullyOpaque(image, w, h, &encoder->infoRaw.color))
+ {
+ /*go to a color type without alpha channel*/
+ if(info.color.colorType == 6) info.color.colorType = 2;
+ else if(info.color.colorType == 4) info.color.colorType = 0;
+ }
+
+ if(encoder->settings.zlibsettings.windowSize > 32768)
+ {
+ encoder->error = 60; /*error: windowsize larger than allowed*/
+ return;
+ }
+ if(encoder->settings.zlibsettings.btype > 2)
+ {
+ encoder->error = 61; /*error: unexisting btype*/
+ return;
+ }
+ if(encoder->infoPng.interlaceMethod > 1)
+ {
+ encoder->error = 71; /*error: unexisting interlace mode*/
+ return;
+ }
+ /*error: unexisting color type given*/
+ if((encoder->error = checkColorValidity(info.color.colorType, info.color.bitDepth))) return;
+ /*error: unexisting color type given*/
+ if((encoder->error = checkColorValidity(encoder->infoRaw.color.colorType, encoder->infoRaw.color.bitDepth))) return;
+
+ if(!LodePNG_InfoColor_equal(&encoder->infoRaw.color, &info.color))
+ {
+ unsigned char* converted;
+ size_t size = (w * h * LodePNG_InfoColor_getBpp(&info.color) + 7) / 8;
+
+ if((info.color.colorType != 6 && info.color.colorType != 2) || (info.color.bitDepth != 8))
+ {
+ encoder->error = 59; /*for the output image, only these types are supported*/
+ return;
+ }
+ converted = (unsigned char*)malloc(size);
+ if(!converted && size) encoder->error = 9955; /*alloc fail*/
+ if(!encoder->error)
+ {
+ encoder->error = LodePNG_convert(converted, image, &info.color, &encoder->infoRaw.color, w, h);
+ }
+ if(!encoder->error) preProcessScanlines(&data, &datasize, converted, &info, &encoder->settings);
+ free(converted);
+ }
+ else preProcessScanlines(&data, &datasize, image, &info, &encoder->settings);
+
+ ucvector_init(&outv);
+ while(!encoder->error) /*while only executed once, to break on error*/
+ {
+#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS
+ size_t i;
+#endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/
+ /*write signature and chunks*/
+ writeSignature(&outv);
+ /*IHDR*/
+ addChunk_IHDR(&outv, w, h, info.color.bitDepth, info.color.colorType, info.interlaceMethod);
+#ifdef LODEPNG_COMPILE_UNKNOWN_CHUNKS
+ /*unknown chunks between IHDR and PLTE*/
+ if(info.unknown_chunks.data[0])
+ {
+ encoder->error = addUnknownChunks(&outv, info.unknown_chunks.data[0], info.unknown_chunks.datasize[0]);
+ if(encoder->error) break;
+ }
+#endif /*LODEPNG_COMPILE_UNKNOWN_CHUNKS*/
+ /*PLTE*/
+ if(info.color.colorType == 3)
+ {
+ if(info.color.palettesize == 0 || info.color.palettesize > 256)
+ {
+ encoder->error = 68; /*invalid palette size*/
+ break;
+ }
+ addChunk_PLTE(&outv, &info.color);
+ }
+ if(encoder->settings.force_palette && (info.color.colorType == 2 || info.color.colorType == 6))
+ {
+ if(info.color.palettesize == 0 || info.color.palettesize > 256)
+ {
+ encoder->error = 68; /*invalid palette size*/
+ break;
+ }
+ addChunk_PLTE(&outv, &info.color);
+ }
+ /*tRNS*/
+ if(info.color.colorType == 3 && !isPaletteFullyOpaque(info.color.palette, info.color.palettesize))
+ {
+ addChunk_tRNS(&outv, &info.color);
+ }
+ if((info.color.colorType == 0 || info.color.colorType == 2) && info.color.key_defined)
+ {
+ addChunk_tRNS(&outv, &info.color);
+ }
+#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS
+ /*bKGD (must come between PLTE and the IDAt chunks*/
+ if(info.background_defined) addChunk_bKGD(&outv, &info);
+ /*pHYs (must come before the IDAT chunks)*/
+ if(info.phys_defined) addChunk_pHYs(&outv, &info);
+#endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/
+#ifdef LODEPNG_COMPILE_UNKNOWN_CHUNKS
+ /*unknown chunks between PLTE and IDAT*/
+ if(info.unknown_chunks.data[1])
+ {
+ encoder->error = addUnknownChunks(&outv, info.unknown_chunks.data[1], info.unknown_chunks.datasize[1]);
+ if(encoder->error) break;
+ }
+#endif /*LODEPNG_COMPILE_UNKNOWN_CHUNKS*/
+ /*IDAT (multiple IDAT chunks must be consecutive)*/
+ encoder->error = addChunk_IDAT(&outv, data, datasize, &encoder->settings.zlibsettings);
+ if(encoder->error) break;
+#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS
+ /*tIME*/
+ if(info.time_defined) addChunk_tIME(&outv, &info.time);
+ /*tEXt and/or zTXt*/
+ for(i = 0; i < info.text.num; i++)
+ {
+ if(strlen(info.text.keys[i]) > 79)
+ {
+ encoder->error = 66; /*text chunk too large*/
+ break;
+ }
+ if(strlen(info.text.keys[i]) < 1)
+ {
+ encoder->error = 67; /*text chunk too small*/
+ break;
+ }
+ if(encoder->settings.text_compression)
+ addChunk_zTXt(&outv, info.text.keys[i], info.text.strings[i], &encoder->settings.zlibsettings);
+ else
+ addChunk_tEXt(&outv, info.text.keys[i], info.text.strings[i]);
+ }
+ /*LodePNG version id in text chunk*/
+ if(encoder->settings.add_id)
+ {
+ unsigned alread_added_id_text = 0;
+ for(i = 0; i < info.text.num; i++)
+ {
+ if(!strcmp(info.text.keys[i], "LodePNG"))
+ {
+ alread_added_id_text = 1;
+ break;
+ }
+ }
+ if(alread_added_id_text == 0)
+ addChunk_tEXt(&outv, "LodePNG", VERSION_STRING); /*it's shorter as tEXt than as zTXt chunk*/
+ }
+ /*iTXt*/
+ for(i = 0; i < info.itext.num; i++)
+ {
+ if(strlen(info.itext.keys[i]) > 79)
+ {
+ encoder->error = 66; /*text chunk too large*/
+ break;
+ }
+ if(strlen(info.itext.keys[i]) < 1)
+ {
+ encoder->error = 67; /*text chunk too small*/
+ break;
+ }
+ addChunk_iTXt(&outv, encoder->settings.text_compression,
+ info.itext.keys[i], info.itext.langtags[i], info.itext.transkeys[i], info.itext.strings[i],
+ &encoder->settings.zlibsettings);
+ }
+#endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/
+#ifdef LODEPNG_COMPILE_UNKNOWN_CHUNKS
+ /*unknown chunks between IDAT and IEND*/
+ if(info.unknown_chunks.data[2])
+ {
+ encoder->error = addUnknownChunks(&outv, info.unknown_chunks.data[2], info.unknown_chunks.datasize[2]);
+ if(encoder->error) break;
+ }
+#endif /*LODEPNG_COMPILE_UNKNOWN_CHUNKS*/
+ /*IEND*/
+ addChunk_IEND(&outv);
+
+ break; /*this isn't really a while loop; no error happened so break out now!*/
+ }
+
+ free(data);
+ /*instead of cleaning the vector up, give it to the output*/
+ *out = outv.data;
+ *outsize = outv.size;
+}
+
+unsigned LodePNG_encode(unsigned char** out, size_t* outsize, const unsigned char* image,
+ unsigned w, unsigned h, unsigned colorType, unsigned bitDepth)
+{
+ unsigned error;
+ LodePNG_Encoder encoder;
+ LodePNG_Encoder_init(&encoder);
+ encoder.infoRaw.color.colorType = colorType;
+ encoder.infoRaw.color.bitDepth = bitDepth;
+ encoder.infoPng.color.colorType = colorType;
+ encoder.infoPng.color.bitDepth = bitDepth;
+ LodePNG_Encoder_encode(&encoder, out, outsize, image, w, h);
+ error = encoder.error;
+ LodePNG_Encoder_cleanup(&encoder);
+ return error;
+}
+
+unsigned LodePNG_encode32(unsigned char** out, size_t* outsize, const unsigned char* image, unsigned w, unsigned h)
+{
+ return LodePNG_encode(out, outsize, image, w, h, 6, 8);
+}
+
+unsigned LodePNG_encode24(unsigned char** out, size_t* outsize, const unsigned char* image, unsigned w, unsigned h)
+{
+ return LodePNG_encode(out, outsize, image, w, h, 2, 8);
+}
+
+#ifdef LODEPNG_COMPILE_DISK
+unsigned LodePNG_encode_file(const char* filename, const unsigned char* image, unsigned w, unsigned h,
+ unsigned colorType, unsigned bitDepth)
+{
+ unsigned char* buffer;
+ size_t buffersize;
+ unsigned error = LodePNG_encode(&buffer, &buffersize, image, w, h, colorType, bitDepth);
+ if(!error) error = LodePNG_saveFile(buffer, buffersize, filename);
+ free(buffer);
+ return error;
+}
+
+unsigned LodePNG_encode32_file(const char* filename, const unsigned char* image, unsigned w, unsigned h)
+{
+ return LodePNG_encode_file(filename, image, w, h, 6, 8);
+}
+
+unsigned LodePNG_encode24_file(const char* filename, const unsigned char* image, unsigned w, unsigned h)
+{
+ return LodePNG_encode_file(filename, image, w, h, 2, 8);
+}
+#endif /*LODEPNG_COMPILE_DISK*/
+
+void LodePNG_EncodeSettings_init(LodePNG_EncodeSettings* settings)
+{
+ LodePNG_CompressSettings_init(&settings->zlibsettings);
+ settings->bruteForceFilters = 0;
+ settings->autoLeaveOutAlphaChannel = 1;
+ settings->force_palette = 0;
+#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS
+ settings->add_id = 1;
+ settings->text_compression = 0;
+#endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/
+}
+
+void LodePNG_Encoder_init(LodePNG_Encoder* encoder)
+{
+ LodePNG_EncodeSettings_init(&encoder->settings);
+ LodePNG_InfoPng_init(&encoder->infoPng);
+ LodePNG_InfoRaw_init(&encoder->infoRaw);
+ encoder->error = 1;
+}
+
+void LodePNG_Encoder_cleanup(LodePNG_Encoder* encoder)
+{
+ LodePNG_InfoPng_cleanup(&encoder->infoPng);
+ LodePNG_InfoRaw_cleanup(&encoder->infoRaw);
+}
+
+void LodePNG_Encoder_copy(LodePNG_Encoder* dest, const LodePNG_Encoder* source)
+{
+ LodePNG_Encoder_cleanup(dest);
+ *dest = *source;
+ LodePNG_InfoPng_init(&dest->infoPng);
+ LodePNG_InfoRaw_init(&dest->infoRaw);
+ dest->error = LodePNG_InfoPng_copy(&dest->infoPng, &source->infoPng);
+ if(dest->error) return;
+ dest->error = LodePNG_InfoRaw_copy(&dest->infoRaw, &source->infoRaw);
+ if(dest->error) return;
+}
+
+#endif /*LODEPNG_COMPILE_ENCODER*/
+
+#endif /*LODEPNG_COMPILE_PNG*/
+
+#ifdef LODEPNG_COMPILE_ERROR_TEXT
+
+/*
+This returns the description of a numerical error code in English. This is also
+the documentation of all the error codes.
+*/
+const char* LodePNG_error_text(unsigned code)
+{
+ switch(code)
+ {
+ case 0: return "no error, everything went ok";
+ case 1: return "nothing done yet"; /*the Encoder/Decoder has done nothing yet, error checking makes no sense yet*/
+ case 10: return "end of input memory reached without huffman end code"; /*while huffman decoding*/
+ case 11: return "error in code tree made it jump outside of huffman tree"; /*while huffman decoding*/
+ case 13: return "problem while processing dynamic deflate block";
+ case 14: return "problem while processing dynamic deflate block";
+ case 15: return "problem while processing dynamic deflate block";
+ case 16: return "unexisting code while processing dynamic deflate block";
+ case 17: return "end of out buffer memory reached while inflating";
+ case 18: return "invalid distance code while inflating";
+ case 19: return "end of out buffer memory reached while inflating";
+ case 20: return "invalid deflate block BTYPE encountered while decoding";
+ case 21: return "NLEN is not ones complement of LEN in a deflate block";
+
+ /*end of out buffer memory reached while inflating:
+ This can happen if the inflated deflate data is longer than the amount of bytes required to fill up
+ all the pixels of the image, given the color depth and image dimensions. Something that doesn't
+ happen in a normal, well encoded, PNG image.*/
+ case 22: return "end of out buffer memory reached while inflating";
+
+ case 23: return "end of in buffer memory reached while inflating";
+ case 24: return "invalid FCHECK in zlib header";
+ case 25: return "invalid compression method in zlib header";
+ case 26: return "FDICT encountered in zlib header while it's not used for PNG";
+ case 27: return "PNG file is smaller than a PNG header";
+ /*Checks the magic file header, the first 8 bytes of the PNG file*/
+ case 28: return "incorrect PNG signature, it's no PNG or corrupted";
+ case 29: return "first chunk is not the header chunk";
+ case 30: return "chunk length too large, chunk broken off at end of file";
+ case 31: return "illegal PNG color type or bpp";
+ case 32: return "illegal PNG compression method";
+ case 33: return "illegal PNG filter method";
+ case 34: return "illegal PNG interlace method";
+ case 35: return "chunk length of a chunk is too large or the chunk too small";
+ case 36: return "illegal PNG filter type encountered";
+ case 37: return "illegal bit depth for this color type given";
+ case 38: return "the palette is too big"; /*more than 256 colors*/
+ case 39: return "more palette alpha values given in tRNS chunk than there are colors in the palette";
+ case 40: return "tRNS chunk has wrong size for greyscale image";
+ case 41: return "tRNS chunk has wrong size for RGB image";
+ case 42: return "tRNS chunk appeared while it was not allowed for this color type";
+ case 43: return "bKGD chunk has wrong size for palette image";
+ case 44: return "bKGD chunk has wrong size for greyscale image";
+ case 45: return "bKGD chunk has wrong size for RGB image";
+ /*Is the palette too small?*/
+ case 46: return "a value in indexed image is larger than the palette size (bitdepth = 8)";
+ /*Is the palette too small?*/
+ case 47: return "a value in indexed image is larger than the palette size (bitdepth < 8)";
+ /*the input data is empty, maybe a PNG file doesn't exist or is in the wrong path*/
+ case 48: return "empty input or file doesn't exist";
+ case 49: return "jumped past memory while generating dynamic huffman tree";
+ case 50: return "jumped past memory while generating dynamic huffman tree";
+ case 51: return "jumped past memory while inflating huffman block";
+ case 52: return "jumped past memory while inflating";
+ case 53: return "size of zlib data too small";
+
+ /*jumped past tree while generating huffman tree, this could be when the
+ tree will have more leaves than symbols after generating it out of the
+ given lenghts. They call this an oversubscribed dynamic bit lengths tree in zlib.*/
+ case 55: return "jumped past tree while generating huffman tree";
+
+ case 56: return "given output image colorType or bitDepth not supported for color conversion";
+ case 57: return "invalid CRC encountered (checking CRC can be disabled)";
+ case 58: return "invalid ADLER32 encountered (checking ADLER32 can be disabled)";
+ case 59: return "conversion to unexisting color mode or color mode conversion not supported";
+ case 60: return "invalid window size given in the settings of the encoder (must be 0-32768)";
+ case 61: return "invalid BTYPE given in the settings of the encoder (only 0, 1 and 2 are allowed)";
+ /*LodePNG leaves the choice of RGB to greyscale conversion formula to the user.*/
+ case 62: return "conversion from RGB to greyscale not supported";
+ case 63: return "length of a chunk too long, max allowed for PNG is 2147483647 bytes per chunk"; /*(2^31-1)*/
+ /*this would result in the inability of a deflated block to ever contain an end code. It must be at least 1.*/
+ case 64: return "the length of the END symbol 256 in the Huffman tree is 0";
+ case 66: return "the length of a text chunk keyword given to the encoder is longer than the maximum of 79 bytes";
+ case 67: return "the length of a text chunk keyword given to the encoder is smaller than the minimum of 1 byte";
+ case 68: return "tried to encode a PLTE chunk with a palette that has less than 1 or more than 256 colors";
+ case 69: return "unknown chunk type with 'critical' flag encountered by the decoder";
+ case 71: return "unexisting interlace mode given to encoder (must be 0 or 1)";
+ case 72: return "while decoding, unexisting compression method encountering in zTXt or iTXt chunk (it must be 0)";
+ case 73: return "invalid tIME chunk size";
+ case 74: return "invalid pHYs chunk size";
+ /*length could be wrong, or data chopped off*/
+ case 75: return "no null termination char found while decoding text chunk";
+ case 76: return "iTXt chunk too short to contain required bytes";
+ case 77: return "integer overflow in buffer size";
+ case 78: return "failed to open file for reading"; /*file doesn't exist or couldn't be opened for reading*/
+ case 79: return "failed to open file for writing";
+ case 80: return "tried creating a tree of 0 symbols";
+ case 81: return "lazy matching at pos 0 is impossible";
+ default: ; /*nothing to do here, checks for other error values are below*/
+ }
+
+ if(code >= 9900 && code <= 9999) return "memory allocation failed";
+
+ return "unknown error code";
+}
+
+#endif /*LODEPNG_COMPILE_ERROR_TEXT*/
+
+/* ////////////////////////////////////////////////////////////////////////// */
+/* ////////////////////////////////////////////////////////////////////////// */
+/* // End of PNG related code. Begin of C++ wrapper. // */
+/* ////////////////////////////////////////////////////////////////////////// */
+/* ////////////////////////////////////////////////////////////////////////// */
+
+#ifdef __cplusplus
+namespace LodePNG
+{
+#ifdef LODEPNG_COMPILE_DISK
+ void loadFile(std::vector<unsigned char>& buffer, const std::string& filename)
+ {
+ std::ifstream file(filename.c_str(), std::ios::in|std::ios::binary|std::ios::ate);
+
+ /*get filesize*/
+ std::streamsize size = 0;
+ if(file.seekg(0, std::ios::end).good()) size = file.tellg();
+ if(file.seekg(0, std::ios::beg).good()) size -= file.tellg();
+
+ /*read contents of the file into the vector*/
+ buffer.resize(size_t(size));
+ if(size > 0) file.read((char*)(&buffer[0]), size);
+ }
+
+ /*write given buffer to the file, overwriting the file, it doesn't append to it.*/
+ void saveFile(const std::vector<unsigned char>& buffer, const std::string& filename)
+ {
+ std::ofstream file(filename.c_str(), std::ios::out|std::ios::binary);
+ file.write(buffer.empty() ? 0 : (char*)&buffer[0], std::streamsize(buffer.size()));
+ }
+#endif //LODEPNG_COMPILE_DISK
+
+/* ////////////////////////////////////////////////////////////////////////// */
+
+#ifdef LODEPNG_COMPILE_ZLIB
+#ifdef LODEPNG_COMPILE_DECODER
+ unsigned decompress(std::vector<unsigned char>& out, const unsigned char* in, size_t insize,
+ const LodePNG_DecompressSettings& settings)
+ {
+ unsigned char* buffer = 0;
+ size_t buffersize = 0;
+ unsigned error = LodePNG_zlib_decompress(&buffer, &buffersize, in, insize, &settings);
+ if(buffer)
+ {
+ out.insert(out.end(), &buffer[0], &buffer[buffersize]);
+ free(buffer);
+ }
+ return error;
+ }
+
+ unsigned decompress(std::vector<unsigned char>& out, const std::vector<unsigned char>& in,
+ const LodePNG_DecompressSettings& settings)
+ {
+ return decompress(out, in.empty() ? 0 : &in[0], in.size(), settings);
+ }
+#endif //LODEPNG_COMPILE_DECODER
+
+#ifdef LODEPNG_COMPILE_ENCODER
+ unsigned compress(std::vector<unsigned char>& out, const unsigned char* in, size_t insize,
+ const LodePNG_CompressSettings& settings)
+ {
+ unsigned char* buffer = 0;
+ size_t buffersize = 0;
+ unsigned error = LodePNG_zlib_compress(&buffer, &buffersize, in, insize, &settings);
+ if(buffer)
+ {
+ out.insert(out.end(), &buffer[0], &buffer[buffersize]);
+ free(buffer);
+ }
+ return error;
+ }
+
+ unsigned compress(std::vector<unsigned char>& out, const std::vector<unsigned char>& in,
+ const LodePNG_CompressSettings& settings)
+ {
+ return compress(out, in.empty() ? 0 : &in[0], in.size(), settings);
+ }
+#endif //LODEPNG_COMPILE_ENCODER
+#endif //LODEPNG_COMPILE_ZLIB
+
+#ifdef LODEPNG_COMPILE_PNG
+#ifdef LODEPNG_COMPILE_DECODER
+ Decoder::Decoder()
+ {
+ LodePNG_Decoder_init(this);
+ }
+
+ Decoder::~Decoder()
+ {
+ LodePNG_Decoder_cleanup(this);
+ }
+
+ void Decoder::operator=(const LodePNG_Decoder& other)
+ {
+ LodePNG_Decoder_copy(this, &other);
+ }
+
+ bool Decoder::hasError() const
+ {
+ return error != 0;
+ }
+ unsigned Decoder::getError() const
+ {
+ return error;
+ }
+
+ unsigned Decoder::getWidth() const
+ {
+ return infoPng.width;
+ }
+
+ unsigned Decoder::getHeight() const
+ {
+ return infoPng.height;
+ }
+
+ unsigned Decoder::getBpp()
+ {
+ return LodePNG_InfoColor_getBpp(&infoPng.color);
+ }
+
+ unsigned Decoder::getChannels()
+ {
+ return LodePNG_InfoColor_getChannels(&infoPng.color);
+ }
+
+ unsigned Decoder::isGreyscaleType()
+ {
+ return LodePNG_InfoColor_isGreyscaleType(&infoPng.color);
+ }
+
+ unsigned Decoder::isAlphaType()
+ {
+ return LodePNG_InfoColor_isAlphaType(&infoPng.color);
+ }
+
+ void Decoder::decode(std::vector<unsigned char>& out, const unsigned char* in, size_t insize)
+ {
+ unsigned char* buffer;
+ size_t buffersize;
+ LodePNG_Decoder_decode(this, &buffer, &buffersize, in, insize);
+ if(buffer)
+ {
+ out.insert(out.end(), &buffer[0], &buffer[buffersize]);
+ free(buffer);
+ }
+ }
+
+ void Decoder::decode(std::vector<unsigned char>& out, const std::vector<unsigned char>& in)
+ {
+ decode(out, in.empty() ? 0 : &in[0], in.size());
+ }
+
+ void Decoder::inspect(const unsigned char* in, size_t insize)
+ {
+ LodePNG_Decoder_inspect(this, in, insize);
+ }
+
+ void Decoder::inspect(const std::vector<unsigned char>& in)
+ {
+ inspect(in.empty() ? 0 : &in[0], in.size());
+ }
+
+ const LodePNG_DecodeSettings& Decoder::getSettings() const
+ {
+ return settings;
+ }
+
+ LodePNG_DecodeSettings& Decoder::getSettings()
+ {
+ return settings;
+ }
+
+ void Decoder::setSettings(const LodePNG_DecodeSettings& settings)
+ {
+ this->settings = settings;
+ }
+
+ const LodePNG_InfoPng& Decoder::getInfoPng() const
+ {
+ return infoPng;
+ }
+
+ LodePNG_InfoPng& Decoder::getInfoPng()
+ {
+ return infoPng;
+ }
+
+ void Decoder::setInfoPng(const LodePNG_InfoPng& info)
+ {
+ error = LodePNG_InfoPng_copy(&this->infoPng, &info);
+ }
+
+ void Decoder::swapInfoPng(LodePNG_InfoPng& info)
+ {
+ LodePNG_InfoPng_swap(&this->infoPng, &info);
+ }
+
+ const LodePNG_InfoRaw& Decoder::getInfoRaw() const
+ {
+ return infoRaw;
+ }
+
+ LodePNG_InfoRaw& Decoder::getInfoRaw()
+ {
+ return infoRaw;
+ }
+
+ void Decoder::setInfoRaw(const LodePNG_InfoRaw& info)
+ {
+ error = LodePNG_InfoRaw_copy(&this->infoRaw, &info);
+ }
+
+#endif //LODEPNG_COMPILE_DECODER
+
+ /* ////////////////////////////////////////////////////////////////////////// */
+
+#ifdef LODEPNG_COMPILE_ENCODER
+
+ Encoder::Encoder()
+ {
+ LodePNG_Encoder_init(this);
+ }
+
+ Encoder::~Encoder()
+ {
+ LodePNG_Encoder_cleanup(this);
+ }
+
+ void Encoder::operator=(const LodePNG_Encoder& other)
+ {
+ LodePNG_Encoder_copy(this, &other);
+ }
+
+ bool Encoder::hasError() const
+ {
+ return error != 0;
+ }
+
+ unsigned Encoder::getError() const
+ {
+ return error;
+ }
+
+ void Encoder::encode(std::vector<unsigned char>& out, const unsigned char* image, unsigned w, unsigned h)
+ {
+ unsigned char* buffer;
+ size_t buffersize;
+ LodePNG_Encoder_encode(this, &buffer, &buffersize, image, w, h);
+ if(buffer)
+ {
+ out.insert(out.end(), &buffer[0], &buffer[buffersize]);
+ free(buffer);
+ }
+ }
+
+ void Encoder::encode(std::vector<unsigned char>& out, const std::vector<unsigned char>& image,
+ unsigned w, unsigned h)
+ {
+ encode(out, image.empty() ? 0 : &image[0], w, h);
+ }
+
+ void Encoder::clearPalette()
+ {
+ LodePNG_InfoColor_clearPalette(&infoPng.color);
+ }
+
+ void Encoder::addPalette(unsigned char r, unsigned char g, unsigned char b, unsigned char a)
+ {
+ error = LodePNG_InfoColor_addPalette(&infoPng.color, r, g, b, a);
+ }
+
+#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS
+ void Encoder::clearText()
+ {
+ LodePNG_Text_clear(&infoPng.text);
+ }
+
+ void Encoder::addText(const std::string& key, const std::string& str)
+ {
+ error = LodePNG_Text_add(&infoPng.text, key.c_str(), str.c_str());
+ }
+
+ void Encoder::clearIText()
+ {
+ LodePNG_IText_clear(&infoPng.itext);
+ }
+
+ void Encoder::addIText(const std::string& key, const std::string& langtag,
+ const std::string& transkey, const std::string& str)
+ {
+ error = LodePNG_IText_add(&infoPng.itext, key.c_str(), langtag.c_str(), transkey.c_str(), str.c_str());
+ }
+#endif //LODEPNG_COMPILE_ANCILLARY_CHUNKS
+
+ const LodePNG_EncodeSettings& Encoder::getSettings() const
+ {
+ return settings;
+ }
+
+ LodePNG_EncodeSettings& Encoder::getSettings()
+ {
+ return settings;
+ }
+
+ void Encoder::setSettings(const LodePNG_EncodeSettings& settings)
+ {
+ this->settings = settings;
+ }
+
+ const LodePNG_InfoPng& Encoder::getInfoPng() const
+ {
+ return infoPng;
+ }
+
+ LodePNG_InfoPng& Encoder::getInfoPng()
+ {
+ return infoPng;
+ }
+
+ void Encoder::setInfoPng(const LodePNG_InfoPng& info)
+ {
+ error = LodePNG_InfoPng_copy(&this->infoPng, &info);
+ }
+
+ void Encoder::swapInfoPng(LodePNG_InfoPng& info)
+ {
+ LodePNG_InfoPng_swap(&this->infoPng, &info);
+ }
+
+ const LodePNG_InfoRaw& Encoder::getInfoRaw() const
+ {
+ return infoRaw;
+ }
+
+ LodePNG_InfoRaw& Encoder::getInfoRaw()
+ {
+ return infoRaw;
+ }
+
+ void Encoder::setInfoRaw(const LodePNG_InfoRaw& info)
+ {
+ error = LodePNG_InfoRaw_copy(&this->infoRaw, &info);
+ }
+#endif //LODEPNG_COMPILE_ENCODER
+
+ /* ////////////////////////////////////////////////////////////////////////// */
+
+#ifdef LODEPNG_COMPILE_DECODER
+
+ unsigned decode(std::vector<unsigned char>& out, unsigned& w, unsigned& h, const unsigned char* in,
+ size_t insize, unsigned colorType, unsigned bitDepth)
+ {
+ Decoder decoder;
+ decoder.getInfoRaw().color.colorType = colorType;
+ decoder.getInfoRaw().color.bitDepth = bitDepth;
+ decoder.decode(out, in, insize);
+ w = decoder.getWidth();
+ h = decoder.getHeight();
+ return decoder.getError();
+ }
+
+ unsigned decode(std::vector<unsigned char>& out, unsigned& w, unsigned& h,
+ const std::vector<unsigned char>& in, unsigned colorType, unsigned bitDepth)
+ {
+ return decode(out, w, h, in.empty() ? 0 : &in[0], (unsigned)in.size(), colorType, bitDepth);
+ }
+
+#ifdef LODEPNG_COMPILE_DISK
+ unsigned decode(std::vector<unsigned char>& out, unsigned& w, unsigned& h, const std::string& filename,
+ unsigned colorType, unsigned bitDepth)
+ {
+ std::vector<unsigned char> buffer;
+ loadFile(buffer, filename);
+ return decode(out, w, h, buffer, colorType, bitDepth);
+ }
+#endif //LODEPNG_COMPILE_DECODER
+#endif //LODEPNG_COMPILE_DISK
+
+#ifdef LODEPNG_COMPILE_ENCODER
+
+ unsigned encode(std::vector<unsigned char>& out, const unsigned char* in, unsigned w, unsigned h,
+ unsigned colorType, unsigned bitDepth)
+ {
+ Encoder encoder;
+ encoder.getInfoRaw().color.colorType = colorType;
+ encoder.getInfoRaw().color.bitDepth = bitDepth;
+ encoder.getInfoPng().color.colorType = colorType;
+ encoder.getInfoPng().color.bitDepth = bitDepth;
+ encoder.encode(out, in, w, h);
+ return encoder.getError();
+ }
+
+ unsigned encode(std::vector<unsigned char>& out, const std::vector<unsigned char>& in, unsigned w, unsigned h,
+ unsigned colorType, unsigned bitDepth)
+ {
+ return encode(out, in.empty() ? 0 : &in[0], w, h, colorType, bitDepth);
+ }
+
+#ifdef LODEPNG_COMPILE_DISK
+ unsigned encode(const std::string& filename, const unsigned char* in, unsigned w, unsigned h,
+ unsigned colorType, unsigned bitDepth)
+ {
+ std::vector<unsigned char> buffer;
+ Encoder encoder;
+ encoder.getInfoRaw().color.colorType = colorType;
+ encoder.getInfoRaw().color.bitDepth = bitDepth;
+ encoder.encode(buffer, in, w, h);
+ if(!encoder.hasError()) saveFile(buffer, filename);
+ return encoder.getError();
+ }
+
+ unsigned encode(const std::string& filename, const std::vector<unsigned char>& in, unsigned w, unsigned h,
+ unsigned colorType, unsigned bitDepth)
+ {
+ return encode(filename, in.empty() ? 0 : &in[0], w, h, colorType, bitDepth);
+ }
+#endif //LODEPNG_COMPILE_DISK
+#endif //LODEPNG_COMPILE_ENCODER
+#endif //LODEPNG_COMPILE_PNG
+} //namespace LodePNG
+#endif /*__cplusplus C++ RAII wrapper*/
diff --git a/src/lodepng.h b/src/lodepng.h
new file mode 100644
index 0000000..a0a654f
--- /dev/null
+++ b/src/lodepng.h
@@ -0,0 +1,1899 @@
+#ifndef LODEPNG_H_
+#define LODEPNG_H_
+
+/*
+LodePNG version 20110908
+
+Copyright (c) 2005-2011 Lode Vandevenne
+
+This software is provided 'as-is', without any express or implied
+warranty. In no event will the authors be held liable for any damages
+arising from the use of this software.
+
+Permission is granted to anyone to use this software for any purpose,
+including commercial applications, and to alter it and redistribute it
+freely, subject to the following restrictions:
+
+ 1. The origin of this software must not be misrepresented; you must not
+ claim that you wrote the original software. If you use this software
+ in a product, an acknowledgment in the product documentation would be
+ appreciated but is not required.
+
+ 2. Altered source versions must be plainly marked as such, and must not be
+ misrepresented as being the original software.
+
+ 3. This notice may not be removed or altered from any source
+ distribution.
+*/
+
+#ifndef LODEPNG_H
+#define LODEPNG_H
+
+#include <string.h> /*for size_t*/
+
+#ifdef __cplusplus
+#include <vector>
+#include <string>
+#endif /*__cplusplus*/
+
+/* ////////////////////////////////////////////////////////////////////////// */
+/* Code Sections */
+/* ////////////////////////////////////////////////////////////////////////// */
+
+/*
+The following #defines are used to create code sections. They can be disabled
+to disable code sections, which can give faster compile time and smaller binary.
+*/
+
+/*deflate&zlib encoder and deflate&zlib decoder.
+If this is disabled, you need to implement the dummy LodePNG_zlib_compress and
+LodePNG_zlib_decompress functions in the #else belonging to this #define in the
+source file.*/
+#define LODEPNG_COMPILE_ZLIB
+/*png encoder and png decoder*/
+#define LODEPNG_COMPILE_PNG
+/*deflate&zlib decoder and png decoder*/
+#define LODEPNG_COMPILE_DECODER
+/*deflate&zlib encoder and png encoder*/
+#define LODEPNG_COMPILE_ENCODER
+/*the optional built in harddisk file loading and saving functions*/
+#define LODEPNG_COMPILE_DISK
+/*any code or struct datamember related to chunks other than IHDR, IDAT, PLTE, tRNS, IEND*/
+#define LODEPNG_COMPILE_ANCILLARY_CHUNKS
+/*handling of unknown chunks*/
+#define LODEPNG_COMPILE_UNKNOWN_CHUNKS
+/*ability to convert error numerical codes to English text string*/
+#define LODEPNG_COMPILE_ERROR_TEXT
+
+/* ////////////////////////////////////////////////////////////////////////// */
+/* Simple Functions */
+/* ////////////////////////////////////////////////////////////////////////// */
+
+/*
+This are the simple C and C++ functions, which cover basic usage.
+Further on in the header file are the more advanced functions allowing custom behaviour.
+*/
+
+#ifdef LODEPNG_COMPILE_PNG
+
+/*constants for the PNG color types. "LCT" = "LodePNG Color Type"*/
+#define LCT_GREY 0 /*PNG color type greyscale*/
+#define LCT_RGB 2 /*PNG color type RGB*/
+#define LCT_PALETTE 3 /*PNG color type palette*/
+#define LCT_GREY_ALPHA 4 /*PNG color type greyscale with alpha*/
+#define LCT_RGBA 6 /*PNG color type RGB with alpha*/
+
+#ifdef LODEPNG_COMPILE_DECODER
+/*
+Converts PNG data in memory to raw pixel data.
+out: Output parameter. Pointer to buffer that will contain the raw pixel data.
+ Its size is w * h * (bytes per pixel), bytes per pixel depends on colorType and bitDepth.
+ Must be freed after usage with free(*out).
+w: Output parameter. Pointer to width of pixel data.
+h: Output parameter. Pointer to height of pixel data.
+in: Memory buffer with the PNG file.
+insize: size of the in buffer.
+colorType: the desired color type for the raw output image. See explanation on PNG color types.
+bitDepth: the desired bit depth for the raw output image. See explanation on PNG color types.
+Return value: LodePNG error code (0 means no error).
+*/
+unsigned LodePNG_decode(unsigned char** out, unsigned* w, unsigned* h,
+ const unsigned char* in, size_t insize, unsigned colorType, unsigned bitDepth);
+
+/*Same as LodePNG_decode, but uses colorType = 6 and bitDepth = 8 by default (32-bit RGBA)*/
+unsigned LodePNG_decode32(unsigned char** out, unsigned* w, unsigned* h,
+ const unsigned char* in, size_t insize);
+
+/*Same as LodePNG_decode, but uses colorType = 2 and bitDepth = 8 by default (24-bit RGB)*/
+unsigned LodePNG_decode24(unsigned char** out, unsigned* w, unsigned* h,
+ const unsigned char* in, size_t insize);
+
+#ifdef LODEPNG_COMPILE_DISK
+/*
+Load PNG from disk, from file with given name.
+out: Output parameter. Pointer to buffer that will contain the raw pixel data.
+ Its size is w * h * (bytes per pixel), bytes per pixel depends on colorType and bitDepth.
+ Must be freed after usage with free(*out).
+w: Output parameter. Pointer to width of pixel data.
+h: Output parameter. Pointer to height of pixel data.
+filename: Path on disk of the PNG file.
+colorType: the desired color type for the raw output image. See explanation on PNG color types.
+bitDepth: the desired bit depth for the raw output image. See explanation on PNG color types.
+Return value: LodePNG error code (0 means no error).
+*/
+unsigned LodePNG_decode_file(unsigned char** out, unsigned* w, unsigned* h,
+ const char* filename, unsigned colorType, unsigned bitDepth);
+
+/*Same as LodePNG_decode_file, but uses colorType = 6 and bitDepth = 8 by default (32-bit RGBA)*/
+unsigned LodePNG_decode32_file(unsigned char** out, unsigned* w, unsigned* h, const char* filename);
+
+/*Same as LodePNG_decode_file, but uses colorType = 2 and bitDepth = 8 by default (24-bit RGB)*/
+unsigned LodePNG_decode24_file(unsigned char** out, unsigned* w, unsigned* h, const char* filename);
+
+
+#endif /*LODEPNG_COMPILE_DISK*/
+#endif /*LODEPNG_COMPILE_DECODER*/
+
+#ifdef LODEPNG_COMPILE_ENCODER
+/*
+Converts raw pixel data into a PNG image in memory. The colorType and bitDepth
+ of the output PNG image cannot be chosen, they are automatically determined
+ by the colorType, bitDepth and content of the input pixel data.
+out: Output parameter. Pointer to buffer that will contain the raw pixel data.
+ Must be freed after usage with free(*out).
+outsize: Output parameter. Pointer to the size in bytes of the out buffer.
+image: The raw pixel data to encode. The size of this buffer should be
+ w * h * (bytes per pixel), bytes per pixel depends on colorType and bitDepth.
+w: width of the raw pixel data in pixels.
+h: height of the raw pixel data in pixels.
+colorType: the color type of the raw input image. See explanation on PNG color types.
+bitDepth: the bit depth of the raw input image. See explanation on PNG color types.
+Return value: LodePNG error code (0 means no error).
+*/
+unsigned LodePNG_encode(unsigned char** out, size_t* outsize,
+ const unsigned char* image, unsigned w, unsigned h, unsigned colorType, unsigned bitDepth);
+
+/*Same as LodePNG_encode, but uses colorType = 6 and bitDepth = 8 by default (32-bit RGBA).*/
+unsigned LodePNG_encode32(unsigned char** out, size_t* outsize, const unsigned char* image, unsigned w, unsigned h);
+
+/*Same as LodePNG_encode, but uses colorType = 2 and bitDepth = 8 by default (24-bit RGB).*/
+unsigned LodePNG_encode24(unsigned char** out, size_t* outsize, const unsigned char* image, unsigned w, unsigned h);
+
+#ifdef LODEPNG_COMPILE_DISK
+
+/*
+Converts raw pixel data into a PNG file on disk. Same as LodePNG_encode, but
+outputs to disk instead of memory buffer.
+filename: path to file on disk to write the PNG image to.
+image: The raw pixel data to encode. The size of this buffer should be
+ w * h * (bytes per pixel), bytes per pixel depends on colorType and bitDepth.
+w: width of the raw pixel data in pixels.
+h: height of the raw pixel data in pixels.
+colorType: the color type of the raw input image. See explanation on PNG color types.
+bitDepth: the bit depth of the raw input image. See explanation on PNG color types.
+Return value: LodePNG error code (0 means no error).
+*/
+unsigned LodePNG_encode_file(const char* filename, const unsigned char* image,
+ unsigned w, unsigned h, unsigned colorType, unsigned bitDepth);
+
+/*Same as LodePNG_encode_file, but uses colorType = 6 and bitDepth = 8 by default (32-bit RGBS).*/
+unsigned LodePNG_encode32_file(const char* filename, const unsigned char* image, unsigned w, unsigned h);
+
+/*Same as LodePNG_encode_file, but uses colorType = 2 and bitDepth = 8 by default (24-bit RGB).*/
+unsigned LodePNG_encode24_file(const char* filename, const unsigned char* image, unsigned w, unsigned h);
+#endif /*LODEPNG_COMPILE_DISK*/
+#endif /*LODEPNG_COMPILE_ENCODER*/
+
+#ifdef __cplusplus
+namespace LodePNG
+{
+
+#ifdef LODEPNG_COMPILE_DECODER
+ /*
+ Converts PNG data in memory to raw pixel data.
+ out: Output parameter, std::vector containing the raw pixel data. Its size
+ will be w * h * (bytes per pixel), where bytes per pixel is 4 if the default
+ colorType=6 and bitDepth=8 is used. The pixels are 32-bit RGBA bit in that case.
+ w: Output parameter, width of the image in pixels.
+ h: Output parameter, height of the image in pixels.
+ in: Memory buffer with the PNG file.
+ insize: size of the in buffer.
+ colorType: the desired color type for the raw output image. See explanation on PNG color types.
+ bitDepth: the desired bit depth for the raw output image. See explanation on PNG color types.
+ Return value: LodePNG error code (0 means no error).
+ */
+ unsigned decode(std::vector<unsigned char>& out, unsigned& w, unsigned& h,
+ const unsigned char* in, size_t insize, unsigned colorType = LCT_RGBA, unsigned bitDepth = 8);
+
+ /*
+ Same as the decode function that takes a unsigned char buffer, but instead of giving
+ a pointer and a size, this takes the input buffer as an std::vector.
+ */
+ unsigned decode(std::vector<unsigned char>& out, unsigned& w, unsigned& h,
+ const std::vector<unsigned char>& in, unsigned colorType = LCT_RGBA, unsigned bitDepth = 8);
+#ifdef LODEPNG_COMPILE_DISK
+ /*
+ Converts PNG file from disk to raw pixel data in memory.
+ out: Output parameter, std::vector containing the raw pixel data. Its size
+ will be w * h * (bytes per pixel), where bytes per pixel is 4 if the default
+ colorType=6 and bitDepth=8 is used. The pixels are 32-bit RGBA bit in that case.
+ w: Output parameter, width of the image in pixels.
+ h: Output parameter, height of the image in pixels.
+ filename: Path to PNG file on disk.
+ colorType: the desired color type for the raw output image. See explanation on PNG color types.
+ bitDepth: the desired bit depth for the raw output image. See explanation on PNG color types.
+ Return value: LodePNG error code (0 means no error).
+ */
+ unsigned decode(std::vector<unsigned char>& out, unsigned& w, unsigned& h,
+ const std::string& filename, unsigned colorType = LCT_RGBA, unsigned bitDepth = 8);
+#endif //LODEPNG_COMPILE_DISK
+#endif //LODEPNG_COMPILE_DECODER
+
+#ifdef LODEPNG_COMPILE_ENCODER
+ /*
+ Converts 32-bit RGBA raw pixel data into a PNG image in memory.
+ out: Output parameter, std::vector containing the PNG image data.
+ in: Memory buffer with raw pixel data. The size of this buffer should be
+ w * h * (bytes per pixel), With the default colorType=6 and bitDepth=8, bytes
+ per pixel should be 4 and the data is a 32-bit RGBA pixel buffer.
+ w: Width of the image in pixels.
+ h: Height of the image in pixels.
+ colorType: the color type of the raw input image. See explanation on PNG color types.
+ bitDepth: the bit depth of the raw input image. See explanation on PNG color types.
+ Return value: LodePNG error code (0 means no error).
+ */
+ unsigned encode(std::vector<unsigned char>& out, const unsigned char* in,
+ unsigned w, unsigned h, unsigned colorType = LCT_RGBA, unsigned bitDepth = 8);
+
+ /*
+ Same as the encode function that takes a unsigned char buffer, but instead of giving
+ a pointer and a size, this takes the input buffer as an std::vector.
+ */
+ unsigned encode(std::vector<unsigned char>& out, const std::vector<unsigned char>& in,
+ unsigned w, unsigned h, unsigned colorType = LCT_RGBA, unsigned bitDepth = 8);
+#ifdef LODEPNG_COMPILE_DISK
+ /*
+ Converts 32-bit RGBA raw pixel data into a PNG file on disk.
+ filename: Path to the file to write the PNG image to.
+ in: Memory buffer with raw pixel data. The size of this buffer should be
+ w * h * (bytes per pixel), With the default colorType=6 and bitDepth=8, bytes
+ per pixel should be 4 and the data is a 32-bit RGBA pixel buffer.
+ w: Width of the image in pixels.
+ h: Height of the image in pixels.
+ colorType: the color type of the raw input image. See explanation on PNG color types.
+ bitDepth: the bit depth of the raw input image. See explanation on PNG color types.
+ Return value: LodePNG error code (0 means no error).
+ */
+ unsigned encode(const std::string& filename, const unsigned char* in,
+ unsigned w, unsigned h, unsigned colorType = LCT_RGBA, unsigned bitDepth = 8);
+
+ /*
+ Same as the encode function that takes a unsigned char buffer, but instead of giving
+ a pointer and a size, this takes the input buffer as an std::vector.
+ */
+ unsigned encode(const std::string& filename, const std::vector<unsigned char>& in,
+ unsigned w, unsigned h, unsigned colorType = LCT_RGBA, unsigned bitDepth = 8);
+#endif //LODEPNG_COMPILE_DISK
+#endif //LODEPNG_COMPILE_ENCODER
+} //namespace LodePNG
+#endif /*__cplusplus*/
+#endif /*LODEPNG_COMPILE_PNG*/
+
+#ifdef LODEPNG_COMPILE_ERROR_TEXT
+/*
+Returns a textual description of the error code, in English. The
+numerical value of the code itself is not included in this description.
+*/
+const char* LodePNG_error_text(unsigned code);
+#endif /*LODEPNG_COMPILE_ERROR_TEXT*/
+
+/* ////////////////////////////////////////////////////////////////////////// */
+/* Inflate & Deflate Setting Structs */
+/* ////////////////////////////////////////////////////////////////////////// */
+
+/*
+These structs contain settings for the decompression and compression of the
+PNG files. Typically you won't need these directly.
+*/
+
+#ifdef LODEPNG_COMPILE_DECODER
+typedef struct LodePNG_DecompressSettings
+{
+ unsigned ignoreAdler32; /*if 1, continue and don't give an error message if the Adler32 checksum is corrupted*/
+} LodePNG_DecompressSettings;
+
+extern const LodePNG_DecompressSettings LodePNG_defaultDecompressSettings;
+void LodePNG_DecompressSettings_init(LodePNG_DecompressSettings* settings);
+#endif /*LODEPNG_COMPILE_DECODER*/
+
+#ifdef LODEPNG_COMPILE_ENCODER
+/*
+Compression settings. Tweaking these settings tweaks the balance between
+speed and compression ratio.
+*/
+typedef struct LodePNG_CompressSettings /*deflate = compress*/
+{
+ /*LZ77 related settings*/
+ unsigned btype; /*the block type for LZ (0, 1, 2 or 3, see zlib standard). Should be 2 for proper compression.*/
+ unsigned useLZ77; /*whether or not to use LZ77. Should be 1 for proper compression.*/
+ unsigned windowSize; /*the maximum is 32768, higher gives more compression but is slower. Typical value: 2048.*/
+} LodePNG_CompressSettings;
+
+extern const LodePNG_CompressSettings LodePNG_defaultCompressSettings;
+void LodePNG_CompressSettings_init(LodePNG_CompressSettings* settings);
+#endif /*LODEPNG_COMPILE_ENCODER*/
+
+#ifdef LODEPNG_COMPILE_PNG
+/* ////////////////////////////////////////////////////////////////////////// */
+/* PNG and Raw Image Information Structs */
+/* ////////////////////////////////////////////////////////////////////////// */
+
+/*
+Info about the color type of an image.
+The same LodePNG_InfoColor struct is used for both the PNG and raw image type,
+even though they are two totally different things.
+*/
+typedef struct LodePNG_InfoColor
+{
+ /*header (IHDR)*/
+ unsigned colorType; /*color type, see PNG standard or documentation further in this header file*/
+ unsigned bitDepth; /*bits per sample, see PNG standard or documentation further in this header file*/
+
+ /*
+ palette (PLTE and tRNS)
+
+ This is a dynamically allocated unsigned char array with the colors of the palette, including alpha.
+ The value palettesize indicates the amount of colors in the palette.
+ The allocated size of the buffer is 4 * palettesize bytes, in order RGBARGBARGBA...
+
+ When encoding a PNG, to store your colors in the palette of the LodePNG_InfoRaw, first use
+ LodePNG_InfoColor_clearPalette, then for each color use LodePNG_InfoColor_addPalette.
+
+ If you encode an image without alpha with palette, don't forget to put value 255 in each A byte of the palette.
+
+ When decoding, by default you can ignore this palette, since LodePNG already
+ fills the palette colors in the pixels of the raw RGBA output.
+ */
+ unsigned char* palette; /*palette in RGBARGBA... order*/
+ size_t palettesize; /*palette size in number of colors (amount of bytes is 4 * palettesize)*/
+
+ /*
+ transparent color key (tRNS)
+ This color uses the same bit depth as the bitDepth value in this struct, which can be 1-bit to 16-bit.
+ For greyscale PNGs, r, g and b will all 3 be set to the same.
+
+ When decoding, by default you can ignore this information, since LodePNG sets
+ pixels with this key to transparent already in the raw RGBA output.
+ */
+ unsigned key_defined; /*is a transparent color key given? 0 = false, 1 = true*/
+ unsigned key_r; /*red/greyscale component of color key*/
+ unsigned key_g; /*green component of color key*/
+ unsigned key_b; /*blue component of color key*/
+} LodePNG_InfoColor;
+
+/*init, cleanup and copy functions to use with this struct*/
+void LodePNG_InfoColor_init(LodePNG_InfoColor* info);
+void LodePNG_InfoColor_cleanup(LodePNG_InfoColor* info);
+/*return value is error code (0 means no error)*/
+unsigned LodePNG_InfoColor_copy(LodePNG_InfoColor* dest, const LodePNG_InfoColor* source);
+
+void LodePNG_InfoColor_clearPalette(LodePNG_InfoColor* info);
+/*add 1 color to the palette*/
+unsigned LodePNG_InfoColor_addPalette(LodePNG_InfoColor* info, unsigned char r,
+ unsigned char g, unsigned char b, unsigned char a);
+
+/*additional color info*/
+
+/*get the total amount of bits per pixel, based on colorType and bitDepth in the struct*/
+unsigned LodePNG_InfoColor_getBpp(const LodePNG_InfoColor* info);
+/*get the amount of color channels used, based on colorType in the struct.
+If a palette is used, it counts as 1 channel.*/
+unsigned LodePNG_InfoColor_getChannels(const LodePNG_InfoColor* info);
+/*is it a greyscale type? (only colorType 0 or 4)*/
+unsigned LodePNG_InfoColor_isGreyscaleType(const LodePNG_InfoColor* info);
+/*has it got an alpha channel? (only colorType 2 or 6)*/
+unsigned LodePNG_InfoColor_isAlphaType(const LodePNG_InfoColor* info);
+/*has it got a palette? (only colorType 3)*/
+unsigned LodePNG_InfoColor_isPaletteType(const LodePNG_InfoColor* info);
+/*only returns true if there is a palette and there is a value in the palette with alpha < 255.
+Loops through the palette to check this.*/
+unsigned LodePNG_InfoColor_hasPaletteAlpha(const LodePNG_InfoColor* info);
+
+/*
+Check if the given color info indicates the possibility of having non-opaque pixels in the PNG image.
+Returns true if the image can have translucent or invisible pixels (it still be opaque if it doesn't use such pixels).
+Returns false if the image can only have opaque pixels.
+In detail, it returns true only if it's a color type with alpha, or has a palette with non-opaque values,
+or if "key_defined" is true.
+*/
+unsigned LodePNG_InfoColor_canHaveAlpha(const LodePNG_InfoColor* info);
+
+#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS
+/*
+The information of a Time chunk in PNG.
+To make the encoder add a time chunk, set time_defined to 1 and fill in
+the correct values in all the time parameters. LodePNG will not fill the current
+time in these values itself, all it does is copy them over into the chunk bytes.
+*/
+typedef struct LodePNG_Time
+{
+ unsigned year; /*2 bytes used (0-65535)*/
+ unsigned char month; /*1-12*/
+ unsigned char day; /*1-31*/
+ unsigned char hour; /*0-23*/
+ unsigned char minute; /*0-59*/
+ unsigned char second; /*0-60 (to allow for leap seconds)*/
+} LodePNG_Time;
+
+/*
+Info about text chunks in a PNG file. The arrays can contain multiple keys
+and strings. The amount of keys and strings is the same. The amount of strings
+ends when the pointer to the string is a null pointer.
+
+They keyword of text chunks gives a short description what the actual text
+represents. There are a few standard standard keywords recognised
+by many programs: Title, Author, Description, Copyright, Creation Time,
+Software, Disclaimer, Warning, Source, Comment. It's allowed to use other keys.
+
+A keyword is minimum 1 character and maximum 79 characters long. It's
+discouraged to use a single line length longer than 79 characters for texts.
+*/
+typedef struct LodePNG_Text /*non-international text*/
+{
+ /*Don't allocate these text buffers yourself. Use the init/cleanup functions
+ correctly and use LodePNG_Text_add and LodePNG_Text_clear.*/
+ size_t num; /*the amount of texts in these char** buffers (there may be more texts in itext)*/
+ char** keys; /*the keyword of a text chunk (e.g. "Comment")*/
+ char** strings; /*the actual text*/
+} LodePNG_Text;
+
+/*init, cleanup and copy functions to use with this struct*/
+void LodePNG_Text_init(LodePNG_Text* text);
+void LodePNG_Text_cleanup(LodePNG_Text* text);
+/*return value is error code (0 means no error)*/
+unsigned LodePNG_Text_copy(LodePNG_Text* dest, const LodePNG_Text* source);
+
+/*Use these functions instead of allocating the char**s manually*/
+void LodePNG_Text_clear(LodePNG_Text* text); /*use this to clear the texts again after you filled them in*/
+unsigned LodePNG_Text_add(LodePNG_Text* text, const char* key, const char* str); /*push back both texts at once*/
+
+/*
+Info about international text chunks in a PNG file. The arrays can contain multiple keys
+and strings. The amount of keys, lengtags, transkeys and strings is the same.
+The amount of strings ends when the pointer to the string is a null pointer.
+
+A keyword is minimum 1 character and maximum 79 characters long. It's
+discouraged to use a single line length longer than 79 characters for texts.
+*/
+typedef struct LodePNG_IText /*international text*/
+{
+ /*Don't allocate these text buffers yourself. Use the init/cleanup functions
+ correctly and use LodePNG_IText_add and LodePNG_IText_clear.*/
+
+ /*the amount of international texts in this PNG*/
+ size_t num;
+ /*the English keyword of the text chunk (e.g. "Comment")*/
+ char** keys;
+ /*the language tag for this text's international language, ISO/IEC 646 string, e.g. ISO 639 language tag*/
+ char** langtags;
+ /*keyword translated to the international language - UTF-8 string*/
+ char** transkeys;
+ /*the actual international text - UTF-8 string*/
+ char** strings;
+} LodePNG_IText;
+
+/*init, cleanup and copy functions to use with this struct*/
+void LodePNG_IText_init(LodePNG_IText* text);
+void LodePNG_IText_cleanup(LodePNG_IText* text);
+/*return value is error code (0 means no error)*/
+unsigned LodePNG_IText_copy(LodePNG_IText* dest, const LodePNG_IText* source);
+
+/*Use these functions instead of allocating the char**s manually*/
+void LodePNG_IText_clear(LodePNG_IText* text); /*use this to clear the itexts again after you filled them in*/
+unsigned LodePNG_IText_add(LodePNG_IText* text, const char* key, const char* langtag,
+ const char* transkey, const char* str); /*push back the 4 texts of 1 chunk at once*/
+#endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/
+
+#ifdef LODEPNG_COMPILE_UNKNOWN_CHUNKS
+/*
+Unknown chunks read from the PNG, or extra chunks the user wants to have added
+in the encoded PNG.
+*/
+typedef struct LodePNG_UnknownChunks
+{
+ /*There are 3 buffers, one for each position in the PNG where unknown chunks can appear
+ each buffer contains all unknown chunks for that position consecutively
+ The 3 buffers are the unknown chunks between certain critical chunks:
+ 0: IHDR-PLTE, 1: PLTE-IDAT, 2: IDAT-IEND
+
+ Do not allocate or traverse this data yourself. Use the chunk traversing functions declared
+ later, such as LodePNG_chunk_next and LodePNG_append_chunk, to read/write this struct.
+ */
+ unsigned char* data[3];
+ size_t datasize[3]; /*size in bytes of the unknown chunks, given for protection*/
+
+} LodePNG_UnknownChunks;
+
+/*init, cleanup and copy functions to use with this struct*/
+void LodePNG_UnknownChunks_init(LodePNG_UnknownChunks* chunks);
+void LodePNG_UnknownChunks_cleanup(LodePNG_UnknownChunks* chunks);
+/*return value is error code (0 means no error)*/
+unsigned LodePNG_UnknownChunks_copy(LodePNG_UnknownChunks* dest, const LodePNG_UnknownChunks* src);
+#endif /*LODEPNG_COMPILE_UNKNOWN_CHUNKS*/
+
+/*
+Information about the PNG image, except pixels and sometimes except width and height.
+*/
+typedef struct LodePNG_InfoPng
+{
+ /*header (IHDR), palette (PLTE) and transparency (tRNS)*/
+
+ /*
+ Note: width and height are only used as information of a decoded PNG image. When encoding one, you don't have
+ to specify width and height in an LodePNG_Info struct, but you give them as parameters of the encode function.
+ The rest of the LodePNG_Info struct IS used by the encoder though!
+ */
+ unsigned width; /*width of the image in pixels (ignored by encoder, but filled in by decoder)*/
+ unsigned height; /*height of the image in pixels (ignored by encoder, but filled in by decoder)*/
+ unsigned compressionMethod; /*compression method of the original file. Always 0.*/
+ unsigned filterMethod; /*filter method of the original file*/
+ unsigned interlaceMethod; /*interlace method of the original file*/
+ LodePNG_InfoColor color; /*color type and bits, palette and transparency of the PNG file*/
+
+#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS
+ /*
+ suggested background color (bKGD)
+ This color uses the same bit depth as the bitDepth value in this struct, which can be 1-bit to 16-bit.
+
+ For greyscale PNGs, r, g and b will all 3 be set to the same. When encoding
+ the encoder writes the red one. For palette PNGs: When decoding, the RGB value
+ will be stored, not a palette index. But when encoding, specify the index of
+ the palette in background_r, the other two are then ignored.
+
+ The decoder does not use this background color to edit the color of pixels.
+ */
+ unsigned background_defined; /*is a suggested background color given?*/
+ unsigned background_r; /*red component of suggested background color*/
+ unsigned background_g; /*green component of suggested background color*/
+ unsigned background_b; /*blue component of suggested background color*/
+
+ /*non-international text chunks (tEXt and zTXt)*/
+ LodePNG_Text text;
+
+ /*international text chunks (iTXt)*/
+ LodePNG_IText itext;
+
+ /*time chunk (tIME)*/
+ unsigned char time_defined; /*if 0, no tIME chunk was or will be generated in the PNG image*/
+ LodePNG_Time time;
+
+ /*phys chunk (pHYs)*/
+ unsigned phys_defined; /*if 0, there is no pHYs chunk and the values below are undefined, if 1 else there is one*/
+ unsigned phys_x; /*pixels per unit in x direction*/
+ unsigned phys_y; /*pixels per unit in y direction*/
+ unsigned char phys_unit; /*may be 0 (unknown unit) or 1 (metre)*/
+#endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/
+
+#ifdef LODEPNG_COMPILE_UNKNOWN_CHUNKS
+ /*unknown chunks*/
+ LodePNG_UnknownChunks unknown_chunks;
+#endif /*LODEPNG_COMPILE_UNKNOWN_CHUNKS*/
+} LodePNG_InfoPng;
+
+/*init, cleanup and copy functions to use with this struct*/
+void LodePNG_InfoPng_init(LodePNG_InfoPng* info);
+void LodePNG_InfoPng_cleanup(LodePNG_InfoPng* info);
+/*return value is error code (0 means no error)*/
+unsigned LodePNG_InfoPng_copy(LodePNG_InfoPng* dest, const LodePNG_InfoPng* source);
+
+/*
+Contains user-chosen information about the raw image data, which is independent of the PNG image
+With raw images, I mean the image data in the form of the simple raw buffer to which the
+compressed PNG data is decoded, or from which a PNG image can be encoded.
+*/
+typedef struct LodePNG_InfoRaw
+{
+ LodePNG_InfoColor color; /*color info of the raw image, note that the same struct as for PNG data is used.*/
+} LodePNG_InfoRaw;
+
+/*init, cleanup and copy functions to use with this struct*/
+void LodePNG_InfoRaw_init(LodePNG_InfoRaw* info);
+void LodePNG_InfoRaw_cleanup(LodePNG_InfoRaw* info);
+/*return value is error code (0 means no error)*/
+unsigned LodePNG_InfoRaw_copy(LodePNG_InfoRaw* dest, const LodePNG_InfoRaw* source);
+
+/*
+Converts raw buffer from one color type to another color type, based on
+LodePNG_InfoColor structs to describe the input and output color type.
+See the reference manual at the end of this header file to see which color conversions are supported.
+return value = LodePNG error code (0 if all went ok, an error if the conversion isn't supported)
+The out buffer must have size (w * h * bpp + 7) / 8, where bpp is the bits per pixel
+of the output color type (LodePNG_InfoColor_getBpp)
+*/
+unsigned LodePNG_convert(unsigned char* out, const unsigned char* in, LodePNG_InfoColor* infoOut,
+ LodePNG_InfoColor* infoIn, unsigned w, unsigned h);
+
+#ifdef LODEPNG_COMPILE_DECODER
+
+/* ////////////////////////////////////////////////////////////////////////// */
+/* LodePNG Decoder */
+/* ////////////////////////////////////////////////////////////////////////// */
+
+/*
+Settings for the decoder. This contains settings for the PNG and the Zlib
+decoder, but not the Info settings from the Info structs.
+*/
+typedef struct LodePNG_DecodeSettings
+{
+ LodePNG_DecompressSettings zlibsettings; /*in here is the setting to ignore Adler32 checksums*/
+
+ unsigned ignoreCrc; /*ignore CRC checksums*/
+ unsigned color_convert; /*whether to convert the PNG to the color type you want. Default: yes*/
+
+#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS
+ unsigned readTextChunks; /*if false but rememberUnknownChunks is true, they're stored in the unknown chunks*/
+#endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/
+
+#ifdef LODEPNG_COMPILE_UNKNOWN_CHUNKS
+ /*store all bytes from unknown chunks in the InfoPng (off by default, useful for a png editor)*/
+ unsigned rememberUnknownChunks;
+#endif /*LODEPNG_COMPILE_UNKNOWN_CHUNKS*/
+} LodePNG_DecodeSettings;
+
+void LodePNG_DecodeSettings_init(LodePNG_DecodeSettings* settings);
+
+/*
+The LodePNG_Decoder struct has most input and output parameters the decoder uses,
+such as the settings, the info of the PNG and the raw data, and the error. Only
+the pixel buffer is not contained in this struct.
+*/
+typedef struct LodePNG_Decoder
+{
+ LodePNG_DecodeSettings settings; /*the decoding settings*/
+ LodePNG_InfoRaw infoRaw; /*specifies the format in which you would like to get the raw pixel buffer*/
+ LodePNG_InfoPng infoPng; /*info of the PNG image obtained after decoding*/
+ unsigned error;
+} LodePNG_Decoder;
+
+/*init, cleanup and copy functions to use with this struct*/
+void LodePNG_Decoder_init(LodePNG_Decoder* decoder);
+void LodePNG_Decoder_cleanup(LodePNG_Decoder* decoder);
+void LodePNG_Decoder_copy(LodePNG_Decoder* dest, const LodePNG_Decoder* source);
+
+/*
+Decode based on a LodePNG_Decoder.
+This function allocates the out buffer and stores the size in *outsize. This buffer
+needs to be freed after usage.
+Other information about the PNG file, such as the size, colorType and extra chunks
+are stored in the infoPng field of the LodePNG_Decoder.
+*/
+void LodePNG_Decoder_decode(LodePNG_Decoder* decoder, unsigned char** out, size_t* outsize,
+ const unsigned char* in, size_t insize);
+
+/*
+Read the PNG header, but not the actual data. This returns only the information
+that is in the header chunk of the PNG, such as width, height and color type. The
+information is placed in the infoPng field of the LodePNG_Decoder.
+*/
+void LodePNG_Decoder_inspect(LodePNG_Decoder* decoder, const unsigned char* in, size_t insize);
+#endif /*LODEPNG_COMPILE_DECODER*/
+
+#ifdef LODEPNG_COMPILE_ENCODER
+/* ////////////////////////////////////////////////////////////////////////// */
+/* LodePNG Encoder */
+/* ////////////////////////////////////////////////////////////////////////// */
+
+/*Settings for the encoder.*/
+typedef struct LodePNG_EncodeSettings
+{
+ LodePNG_CompressSettings zlibsettings; /*settings for the zlib encoder, such as window size, ...*/
+
+ /*Brute-force-search PNG filters by compressing each filter for each scanline.
+ This gives better compression, at the cost of being super slow.
+ Don't enable this for normal image saving, compression can take minutes
+ instead of seconds. This is experimental. If enabled, compression still isn't
+ as good as some other PNG encoders and optimizers, except for some images.
+ If you enable this, also consider setting zlibsettings.windowSize to 32768, and consider
+ using a less than 24-bit per pixel colorType if the image has <= 256 colors, for optimal compression.
+ Default: 0 (false)*/
+ unsigned bruteForceFilters;
+
+ /*automatically use color type without alpha instead of given one, if given image is opaque*/
+ unsigned autoLeaveOutAlphaChannel;
+ /*force creating a PLTE chunk if colortype is 2 or 6 (= a suggested palette).
+ If colortype is 3, PLTE is _always_ created.*/
+ unsigned force_palette;
+#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS
+ /*add LodePNG version as text chunk*/
+ unsigned add_id;
+ /*encode text chunks as zTXt chunks instead of tEXt chunks, and use compression in iTXt chunks*/
+ unsigned text_compression;
+#endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/
+} LodePNG_EncodeSettings;
+
+void LodePNG_EncodeSettings_init(LodePNG_EncodeSettings* settings);
+
+/*
+This struct has most input and output parameters the encoder uses,
+such as the settings, the info of the PNG and the raw data, and the error. Only
+the pixel buffer is not contained in this struct.
+*/
+typedef struct LodePNG_Encoder
+{
+ /*compression settings of the encoder*/
+ LodePNG_EncodeSettings settings;
+ /*the info specified by the user is not changed by the encoder. The encoder
+ will try to generate a PNG close to the given info.*/
+ LodePNG_InfoPng infoPng;
+ /*put the properties of the input raw image in here*/
+ LodePNG_InfoRaw infoRaw;
+ /*error value filled in if error happened, or 0 if all went ok*/
+ unsigned error;
+} LodePNG_Encoder;
+
+/*init, cleanup and copy functions to use with this struct*/
+void LodePNG_Encoder_init(LodePNG_Encoder* encoder);
+void LodePNG_Encoder_cleanup(LodePNG_Encoder* encoder);
+void LodePNG_Encoder_copy(LodePNG_Encoder* dest, const LodePNG_Encoder* source);
+
+/*This function allocates the out buffer with standard malloc and stores the size in *outsize.*/
+void LodePNG_Encoder_encode(LodePNG_Encoder* encoder, unsigned char** out, size_t* outsize,
+ const unsigned char* image, unsigned w, unsigned h);
+#endif /*LODEPNG_COMPILE_ENCODER*/
+
+/* ////////////////////////////////////////////////////////////////////////// */
+/* Chunk Traversing Utilities */
+/* ////////////////////////////////////////////////////////////////////////// */
+
+/*
+LodePNG_chunk functions:
+These functions need as input a large enough amount of allocated memory.
+These functions can be used on raw PNG data, but they are exposed in the API
+because they are needed if you want to traverse the unknown chunks stored
+in the LodePNG_UnknownChunks struct, or add new ones to it.
+*/
+
+/*get the length of the data of the chunk. Total chunk length has 12 bytes more.*/
+unsigned LodePNG_chunk_length(const unsigned char* chunk);
+
+/*puts the 4-byte type in null terminated string*/
+void LodePNG_chunk_type(char type[5], const unsigned char* chunk);
+
+/*check if the type is the given type*/
+unsigned char LodePNG_chunk_type_equals(const unsigned char* chunk, const char* type);
+
+/*
+These functions get properties of PNG chunks gotten from capitalization of chunk
+type name, as defined by the PNG standard.
+*/
+
+/*
+properties of PNG chunks gotten from capitalization of chunk type name, as defined by the standard
+0: ancillary chunk, 1: it's one of the critical chunk types
+*/
+unsigned char LodePNG_chunk_critical(const unsigned char* chunk);
+
+/*0: public, 1: private*/
+unsigned char LodePNG_chunk_private(const unsigned char* chunk);
+
+/*0: the chunk is unsafe to copy, 1: the chunk is safe to copy*/
+unsigned char LodePNG_chunk_safetocopy(const unsigned char* chunk);
+
+/*get pointer to the data of the chunk*/
+unsigned char* LodePNG_chunk_data(unsigned char* chunk);
+
+/*get pointer to the data of the chunk*/
+const unsigned char* LodePNG_chunk_data_const(const unsigned char* chunk);
+
+/*returns 0 if the crc is correct, 1 if it's incorrect*/
+unsigned LodePNG_chunk_check_crc(const unsigned char* chunk);
+
+/*generates the correct CRC from the data and puts it in the last 4 bytes of the chunk*/
+void LodePNG_chunk_generate_crc(unsigned char* chunk);
+
+/*iterate to next chunks. don't use on IEND chunk, as there is no next chunk then*/
+unsigned char* LodePNG_chunk_next(unsigned char* chunk);
+const unsigned char* LodePNG_chunk_next_const(const unsigned char* chunk);
+
+/*
+Appends chunk to the data in out. The given chunk should already have its chunk header.
+The out variable and outlength are updated to reflect the new reallocated buffer.
+Returns error code (0 if it went ok)
+*/
+unsigned LodePNG_append_chunk(unsigned char** out, size_t* outlength, const unsigned char* chunk);
+
+/*
+Appends new chunk to out. The chunk to append is given by giving its length, type
+and data separately. The type is a 4-letter string.
+The out variable and outlength are updated to reflect the new reallocated buffer.
+Returne error code (0 if it went ok)
+*/
+unsigned LodePNG_create_chunk(unsigned char** out, size_t* outlength, unsigned length,
+ const char* type, const unsigned char* data);
+#endif /*LODEPNG_COMPILE_PNG*/
+
+#ifdef LODEPNG_COMPILE_ZLIB
+/* ////////////////////////////////////////////////////////////////////////// */
+/* Zlib encoder and decoder */
+/* ////////////////////////////////////////////////////////////////////////// */
+
+/*
+This zlib part can be used independently to zlib compress and decompress a
+buffer. It cannot be used to create gzip files however, and it only supports the
+part of zlib that is required for PNG, it does not support dictionaries.
+*/
+
+#ifdef LODEPNG_COMPILE_DECODER
+/*Decompresses Zlib data. Reallocates the out buffer and appends the data. The
+data must be according to the zlib specification.
+Either, *out must be NULL and *outsize must be 0, or, *out must be a valid
+buffer and *outsize its size in bytes. out must be freed by user after usage.*/
+unsigned LodePNG_zlib_decompress(unsigned char** out, size_t* outsize,
+ const unsigned char* in, size_t insize, const LodePNG_DecompressSettings* settings);
+#endif /*LODEPNG_COMPILE_DECODER*/
+
+#ifdef LODEPNG_COMPILE_ENCODER
+/*Compresses data with Zlib. Reallocates the out buffer and appends the data.
+The data is output in the format of the zlib specification.
+Either, *out must be NULL and *outsize must be 0, or, *out must be a valid
+buffer and *outsize its size in bytes. out must be freed by user after usage.*/
+unsigned LodePNG_zlib_compress(unsigned char** out, size_t* outsize,
+ const unsigned char* in, size_t insize, const LodePNG_CompressSettings* settings);
+#endif /*LODEPNG_COMPILE_ENCODER*/
+#endif /*LODEPNG_COMPILE_ZLIB*/
+
+#ifdef LODEPNG_COMPILE_DISK
+/*
+Load a file from disk into buffer. The function allocates the out buffer, and
+after usage you are responsible for freeing it.
+out: output parameter, contains pointer to loaded buffer.
+outsize: output parameter, size of the allocated out buffer
+filename: the path to the file to load
+return value: error code (0 means ok)
+*/
+unsigned LodePNG_loadFile(unsigned char** out, size_t* outsize, const char* filename);
+
+/*
+Save a file from buffer to disk. Warning, if it exists, this function overwrites
+the file without warning!
+buffer: the buffer to write
+buffersize: size of the buffer to write
+filename: the path to the file to save to
+return value: error code (0 means ok)
+*/
+unsigned LodePNG_saveFile(const unsigned char* buffer, size_t buffersize, const char* filename);
+#endif /*LODEPNG_COMPILE_DISK*/
+
+#ifdef __cplusplus
+/* ////////////////////////////////////////////////////////////////////////// */
+/* LodePNG C++ wrapper */
+/* ////////////////////////////////////////////////////////////////////////// */
+
+//The LodePNG C++ wrapper uses classes with handy constructors and destructors
+//instead of manual init and cleanup functions, and uses std::vectors instead of
+//manually allocated memory buffers.
+
+namespace LodePNG
+{
+#ifdef LODEPNG_COMPILE_ZLIB
+//The C++ wrapper for the zlib part
+#ifdef LODEPNG_COMPILE_DECODER
+ //Zlib-decompress an unsigned char buffer
+ unsigned decompress(std::vector<unsigned char>& out, const unsigned char* in, size_t insize,
+ const LodePNG_DecompressSettings& settings = LodePNG_defaultDecompressSettings);
+
+ //Zlib-decompress an std::vector
+ unsigned decompress(std::vector<unsigned char>& out, const std::vector<unsigned char>& in,
+ const LodePNG_DecompressSettings& settings = LodePNG_defaultDecompressSettings);
+#endif //LODEPNG_COMPILE_DECODER
+
+#ifdef LODEPNG_COMPILE_ENCODER
+ //Zlib-compress an unsigned char buffer
+ unsigned compress(std::vector<unsigned char>& out, const unsigned char* in, size_t insize,
+ const LodePNG_CompressSettings& settings = LodePNG_defaultCompressSettings);
+
+ //Zlib-compress an std::vector
+ unsigned compress(std::vector<unsigned char>& out, const std::vector<unsigned char>& in,
+ const LodePNG_CompressSettings& settings = LodePNG_defaultCompressSettings);
+#endif //LODEPNG_COMPILE_ENCODER
+#endif //LODEPNG_COMPILE_ZLIB
+
+#ifdef LODEPNG_COMPILE_PNG
+#ifdef LODEPNG_COMPILE_DECODER
+ /*
+ Class to decode a PNG image. Before decoding, settings can be set and
+ after decoding, extra information about the PNG can be retrieved.
+ Extends from the C-struct LodePNG_Decoder to add constructors and destructors
+ to initialize/cleanup it automatically. Beware, no virtual destructor is used.
+ */
+ class Decoder : public LodePNG_Decoder
+ {
+ public:
+
+ Decoder();
+ ~Decoder();
+ void operator=(const LodePNG_Decoder& other);
+
+ //decode PNG buffer to raw out buffer. Width and height can be retrieved with getWidth() and
+ //getHeight() and error should be checked with hasError() and getError()
+ void decode(std::vector<unsigned char>& out, const unsigned char* in, size_t insize);
+
+ //decode PNG buffer to raw out buffer. Width and height can be retrieved with getWidth() and
+ //getHeight() and error should be checked with hasError() and getError()
+ void decode(std::vector<unsigned char>& out, const std::vector<unsigned char>& in);
+
+ //inspect functions: get only the info from the PNG header. The info can then be retrieved with
+ //the functions of this class.
+ void inspect(const unsigned char* in, size_t insize);
+
+ //inspect functions: get only the info from the PNG header. The info can then be retrieved with
+ //the functions of this class.
+ void inspect(const std::vector<unsigned char>& in);
+
+ //error checking after decoding
+ bool hasError() const;
+ unsigned getError() const;
+
+ //convenient access to some InfoPng parameters after decoding
+ unsigned getWidth() const; //width of image in pixels
+ unsigned getHeight() const; //height of image in pixels
+ unsigned getBpp(); //bits per pixel
+ unsigned getChannels(); //amount of channels
+ unsigned isGreyscaleType(); //is it a greyscale type? (colorType 0 or 4)
+ unsigned isAlphaType(); //has it an alpha channel? (colorType 2 or 6)
+
+ //getters and setters for the decoding settings
+ const LodePNG_DecodeSettings& getSettings() const;
+ LodePNG_DecodeSettings& getSettings();
+ void setSettings(const LodePNG_DecodeSettings& info);
+
+ //getters and setters for the PNG image info, after decoding this describes information of the PNG image
+ const LodePNG_InfoPng& getInfoPng() const;
+ LodePNG_InfoPng& getInfoPng();
+ void setInfoPng(const LodePNG_InfoPng& info);
+ void swapInfoPng(LodePNG_InfoPng& info); //faster than copying with setInfoPng
+
+ //getters and setters for the raw image info, this determines in what format
+ //you get the pixel buffer from the decoder
+ const LodePNG_InfoRaw& getInfoRaw() const;
+ LodePNG_InfoRaw& getInfoRaw();
+ void setInfoRaw(const LodePNG_InfoRaw& info);
+ };
+#endif //LODEPNG_COMPILE_DECODER
+
+#ifdef LODEPNG_COMPILE_ENCODER
+ /*
+ Class to encode a PNG image. Before encoding, settings can be set.
+ Extends from the C-struct LodePNG_Enoder to add constructors and destructors
+ to initialize/cleanup it automatically. Beware, no virtual destructor is used.
+ */
+ class Encoder : public LodePNG_Encoder
+ {
+ public:
+
+ Encoder();
+ ~Encoder();
+ void operator=(const LodePNG_Encoder& other);
+
+ //encoding image to PNG buffer
+ void encode(std::vector<unsigned char>& out, const unsigned char* image, unsigned w, unsigned h);
+
+ //encoding image to PNG buffer
+ void encode(std::vector<unsigned char>& out, const std::vector<unsigned char>& image, unsigned w, unsigned h);
+
+ //error checking after decoding
+ bool hasError() const;
+ unsigned getError() const;
+
+ //convenient direct access to some parameters of the InfoPng
+ void clearPalette();
+ void addPalette(unsigned char r, unsigned char g, unsigned char b, unsigned char a); //add 1 color to the palette
+#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS
+ void clearText();
+ void addText(const std::string& key, const std::string& str); //push back both texts at once
+ void clearIText();
+ void addIText(const std::string& key, const std::string& langtag,
+ const std::string& transkey, const std::string& str);
+#endif //LODEPNG_COMPILE_ANCILLARY_CHUNKS
+
+ //getters and setters for the encoding settings
+ const LodePNG_EncodeSettings& getSettings() const;
+ LodePNG_EncodeSettings& getSettings();
+ void setSettings(const LodePNG_EncodeSettings& info);
+
+ //getters and setters for the PNG image info, this describes what color type
+ //and other settings the resulting PNG should have
+ const LodePNG_InfoPng& getInfoPng() const;
+ LodePNG_InfoPng& getInfoPng();
+ void setInfoPng(const LodePNG_InfoPng& info);
+ void swapInfoPng(LodePNG_InfoPng& info); //faster than copying with setInfoPng
+
+ //getters and setters for the raw image info, this describes how the encoder
+ //should interpret the input pixel buffer
+ const LodePNG_InfoRaw& getInfoRaw() const;
+ LodePNG_InfoRaw& getInfoRaw();
+ void setInfoRaw(const LodePNG_InfoRaw& info);
+ };
+#endif //LODEPNG_COMPILE_ENCODER
+
+#ifdef LODEPNG_COMPILE_DISK
+ /*
+ Load a file from disk into an std::vector. If the vector is empty, then either
+ the file doesn't exist or is an empty file.
+ */
+ void loadFile(std::vector<unsigned char>& buffer, const std::string& filename);
+
+ /*
+ Save the binary data in an std::vector to a file on disk. The file is overwritten
+ without warning.
+ */
+ void saveFile(const std::vector<unsigned char>& buffer, const std::string& filename);
+#endif //LODEPNG_COMPILE_DISK
+#endif //LODEPNG_COMPILE_PNG
+} //namespace LodePNG
+#endif /*end of __cplusplus wrapper*/
+
+/*
+TODO:
+[.] test if there are no memory leaks or security exploits - done a lot but needs to be checked often
+[.] check compatibility with vareous compilers - done but needs to be redone for every newer version
+[ ] LZ77 encoder more like the one described in zlib - to make sure it's patentfree
+[X] converting color to 16-bit per channel types
+[ ] read all public PNG chunk types (but never let the color profile and gamma ones touch RGB values)
+[ ] make sure encoder generates no chunks with size > (2^31)-1
+[ ] partial decoding (stream processing)
+[ ] let the "isFullyOpaque" function check color keys and transparent palettes too
+[X] better name for the variables "codes", "codesD", "codelengthcodes", "clcl" and "lldl"
+[ ] don't stop decoding on errors like 69, 57, 58 (make warnings)
+[ ] make option to choose if the raw image with non multiple of 8 bits per scanline should have padding bits or not
+[ ] let the C++ wrapper catch exceptions coming from the standard library and return LodePNG error codes
+*/
+
+#endif /*LODEPNG_H inclusion guard*/
+
+/*
+LodePNG Documentation
+---------------------
+
+This documentations contains background information and examples. For the function
+and class documentation, see the comments in the declarations above.
+
+0. table of contents
+--------------------
+
+ 1. about
+ 1.1. supported features
+ 1.2. features not supported
+ 2. C and C++ version
+ 3. security
+ 4. decoding
+ 5. encoding
+ 6. color conversions
+ 6.1. PNG color types
+ 6.2. Default Behaviour of LodePNG
+ 6.3. Color Conversions
+ 6.4. More Notes
+ 7. error values
+ 8. chunks and PNG editing
+ 9. compiler support
+ 10. examples
+ 10.1. decoder C++ example
+ 10.2. encoder C++ example
+ 10.3. decoder C example
+ 11. changes
+ 12. contact information
+
+
+1. about
+--------
+
+PNG is a file format to store raster images losslessly with good compression,
+supporting different color types. It can be implemented in a patent-free way.
+
+LodePNG is a PNG codec according to the Portable Network Graphics (PNG)
+Specification (Second Edition) - W3C Recommendation 10 November 2003.
+
+The specifications used are:
+
+*) Portable Network Graphics (PNG) Specification (Second Edition):
+ http://www.w3.org/TR/2003/REC-PNG-20031110
+*) RFC 1950 ZLIB Compressed Data Format version 3.3:
+ http://www.gzip.org/zlib/rfc-zlib.html
+*) RFC 1951 DEFLATE Compressed Data Format Specification ver 1.3:
+ http://www.gzip.org/zlib/rfc-deflate.html
+
+The most recent version of LodePNG can currently be found at
+http://members.gamedev.net/lode/projects/LodePNG/
+
+LodePNG works both in C (ISO C90) and C++, with a C++ wrapper that adds
+extra functionality.
+
+LodePNG exists out of two files:
+-lodepng.h: the header file for both C and C++
+-lodepng.c(pp): give it the name lodepng.c or lodepng.cpp (or .cc) depending on your usage
+
+If you want to start using LodePNG right away without reading this doc, get the
+files lodepng_examples.c or lodepng_examples.cpp to see how to use it in code,
+or check the (smaller) examples in chapter 13 here.
+
+LodePNG is simple but only supports the basic requirements. To achieve
+simplicity, the following design choices were made: There are no dependencies
+on any external library. To decode PNGs, there's a Decoder struct or class that
+can convert any PNG file data into an RGBA image buffer with a single function
+call. To encode PNGs, there's an Encoder struct or class that can convert image
+data into PNG file data with a single function call. To read and write files,
+there are simple functions to convert the files to/from buffers in memory.
+
+This all makes LodePNG suitable for loading textures in games, demoscene
+productions, saving a screenshot, images in programs that require them for simple
+usage, ... It's less suitable for full fledged image editors, loading PNGs
+over network (it requires all the image data to be available before decoding can
+begin), life-critical systems, ...
+LodePNG has a standards conformant decoder and encoder, and supports the ability
+to make a somewhat conformant editor.
+
+1.1. supported features
+-----------------------
+
+The following features are supported by the decoder:
+
+*) decoding of PNGs with any color type, bit depth and interlace mode, to a 24- or 32-bit color raw image,
+ or the same color type as the PNG
+*) encoding of PNGs, from any raw image to 24- or 32-bit color, or the same color type as the raw image
+*) Adam7 interlace and deinterlace for any color type
+*) loading the image from harddisk or decoding it from a buffer from other sources than harddisk
+*) support for alpha channels, including RGBA color model, translucent palettes and color keying
+*) zlib decompression (inflate)
+*) zlib compression (deflate)
+*) CRC32 and ADLER32 checksums
+*) handling of unknown chunks, allowing making a PNG editor that stores custom and unknown chunks.
+*) the following chunks are supported (generated/interpreted) by both encoder and decoder:
+ IHDR: header information
+ PLTE: color palette
+ IDAT: pixel data
+ IEND: the final chunk
+ tRNS: transparency for palettized images
+ tEXt: textual information
+ zTXt: compressed textual information
+ iTXt: international textual information
+ bKGD: suggested background color
+ pHYs: physical dimensions
+ tIME: modification time
+
+1.2. features not supported
+---------------------------
+
+The following features are _not_ supported:
+
+*) some features needed to make a conformant PNG-Editor might be still missing.
+*) partial loading/stream processing. All data must be available and is processed in one call.
+*) The following public chunks are not supported but treated as unknown chunks by LodePNG
+ cHRM, gAMA, iCCP, sRGB, sBIT, hIST, sPLT
+
+
+2. C and C++ version
+--------------------
+
+The C version uses buffers allocated with alloc that you need to free()
+yourself. On top of that, you need to use init and cleanup functions for each
+struct whenever using a struct from the C version to avoid exploits and memory leaks.
+
+The C++ version has constructors and destructors that take care of these things,
+and uses std::vectors in the interface for storing data.
+
+Both the C and the C++ version are contained in this file! The C++ code depends on
+the C code, the C code works on its own.
+
+These files work without modification for both C and C++ compilers because all the
+additional C++ code is in "#ifdef __cplusplus" blocks that make C-compilers ignore
+it, and the C code is made to compile both with strict ISO C90 and C++.
+
+To use the C++ version, you need to rename the source file to lodepng.cpp (instead
+of lodepng.c), and compile it with a C++ compiler.
+
+To use the C version, you need to rename the source file to lodepng.c (instead
+of lodepng.cpp), and compile it with a C compiler.
+
+
+3. Security
+-----------
+
+As with most software, even if carefully designed, it's always possible that
+LodePNG may contain possible exploits.
+
+If you discover a possible exploit, please let me know, and it will be fixed.
+
+When using LodePNG, care has to be taken with the C version of LodePNG, as well as the C-style
+structs when working with C++. The following conventions are used for all C-style structs:
+
+-if a struct has a corresponding init function, always call the init function when making a new one, to avoid exploits
+-if a struct has a corresponding cleanup function, call it before the struct disappears to avoid memory leaks
+-if a struct has a corresponding copy function, use the copy function instead of "=".
+ The destination must also be inited already!
+
+4. Decoding
+-----------
+
+Decoding converts a PNG compressed image to a raw pixel buffer.
+
+Most documentation on using the decoder is at its declarations in the header
+above. For C, simple decoding can be done with functions such as LodePNG_decode32,
+and more advanced decoding can be done with the struct LodePNG_Decoder and its
+functions. For C++, simple decoding can be done with the LodePNG::decode functions
+and advanced decoding with the LodePNG::Decoder class.
+
+The Decoder contains 3 components:
+*) LodePNG_InfoPng: it stores information about the PNG (the input) in an LodePNG_InfoPng struct,
+ don't modify this one yourself
+*) Settings: you can specify a few other settings for the decoder to use
+*) LodePNG_InfoRaw: here you can say what type of raw image (the output) you want to get
+
+Some of the parameters described below may be inside the sub-struct "LodePNG_InfoColor color".
+In the C and C++ version, when using Info structs outside of the decoder or encoder, you need to use their
+init and cleanup functions, but normally you use the ones in the decoder that are already handled
+in the init and cleanup functions of the decoder itself.
+
+=LodePNG_InfoPng=
+
+This contains information such as the original color type of the PNG image, text
+comments, suggested background color, etc... More details about the LodePNG_InfoPng struct
+are at its declaration documentation.
+
+Because the dimensions of the image are important, there are shortcuts to get them in the
+C++ version: use decoder.getWidth() and decoder.getHeight().
+In the C version, use decoder.infoPng.width and decoder.infoPng.height.
+
+=LodePNG_InfoRaw=
+
+In the LodePNG_InfoRaw struct of the Decoder, you can specify which color type you want
+the resulting raw image to be. If this is different from the colorType of the
+PNG, then the decoder will automatically convert the result to your LodePNG_InfoRaw
+settings. Not all combinations of color conversions are supported though, see
+a different section for information about the color modes and supported conversions.
+
+Palette of LodePNG_InfoRaw isn't used by the Decoder, when converting from palette color
+to palette color, the values of the pixels are left untouched so that the colors
+will change if the palette is different. Color key of LodePNG_InfoRaw is not used by the
+Decoder. If setting color_convert is false then LodePNG_InfoRaw is completely ignored,
+but it will be modified to match the color type of the PNG so will be overwritten.
+
+By default, 32-bit color is used for the result.
+
+=Settings=
+
+The Settings can be used to ignore the errors created by invalid CRC and Adler32
+chunks, and to disable the decoding of tEXt chunks.
+
+There's also a setting color_convert, true by default. If false, no conversion
+is done, the resulting data will be as it was in the PNG (after decompression)
+and you'll have to puzzle the colors of the pixels together yourself using the
+color type information in the LodePNG_InfoPng.
+
+
+5. Encoding
+-----------
+
+Encoding converts a raw pixel buffer to a PNG compressed image.
+
+Most documentation on using the encoder is at its declarations in the header
+above. For C, simple encoding can be done with functions such as LodePNG_encode32,
+and more advanced decoding can be done with the struct LodePNG_Encoder and its
+functions. For C++, simple encoding can be done with the LodePNG::encode functions
+and advanced decoding with the LodePNG::Encoder class.
+
+Like the decoder, the encoder can also give errors. However it gives less errors
+since the encoder input is trusted, the decoder input (a PNG image that could
+be forged by anyone) is not trusted.
+
+Like the Decoder, the Encoder has 3 components:
+*) LodePNG_InfoRaw: here you say what color type of the raw image (the input) has
+*) Settings: you can specify a few settings for the encoder to use
+*) LodePNG_InfoPng: the same LodePNG_InfoPng struct as created by the Decoder. For the encoder,
+with this you specify how you want the PNG (the output) to be.
+
+Some of the parameters described below may be inside the sub-struct "LodePNG_InfoColor color".
+In the C and C++ version, when using Info structs outside of the decoder or encoder, you need to use their
+init and cleanup functions, but normally you use the ones in the encoder that are already handled
+in the init and cleanup functions of the decoder itself.
+
+=LodePNG_InfoPng=
+
+The Decoder class stores information about the PNG image in an LodePNG_InfoPng object. With
+the Encoder you can do the opposite: you give it an LodePNG_InfoPng object, and it'll try
+to match the LodePNG_InfoPng you give as close as possible in the PNG it encodes. For
+example in the LodePNG_InfoPng you can specify the color type you want to use, possible
+tEXt chunks you want the PNG to contain, etc... For an explanation of all the
+values in LodePNG_InfoPng see a further section. Not all PNG color types are supported
+by the Encoder.
+
+The encoder will not always exactly match the LodePNG_InfoPng struct you give,
+it tries as close as possible. Some things are ignored by the encoder. The width
+and height of LodePNG_InfoPng are ignored as well, because instead the width and
+height of the raw image you give in the input are used. In fact the encoder
+currently uses only the following settings from it:
+-colorType and bitDepth: the ones it supports
+-text chunks, that you can add to the LodePNG_InfoPng with "addText"
+-the color key, if applicable for the given color type
+-the palette, if you encode to a PNG with colorType 3
+-the background color: it'll add a bKGD chunk to the PNG if one is given
+-the interlaceMethod: None (0) or Adam7 (1)
+
+When encoding to a PNG with colorType 3, the encoder will generate a PLTE chunk.
+If the palette contains any colors for which the alpha channel is not 255 (so
+there are translucent colors in the palette), it'll add a tRNS chunk.
+
+=LodePNG_InfoRaw=
+
+You specify the color type of the raw image that you give to the input here,
+including a possible transparent color key and palette you happen to be using in
+your raw image data.
+
+By default, 32-bit color is assumed, meaning your input has to be in RGBA
+format with 4 bytes (unsigned chars) per pixel.
+
+=Settings=
+
+The following settings are supported (some are in sub-structs):
+*) autoLeaveOutAlphaChannel: when this option is enabled, when you specify a PNG
+color type with alpha channel (not to be confused with the color type of the raw
+image you specify!!), but the encoder detects that all pixels of the given image
+are opaque, then it'll automatically use the corresponding type without alpha
+channel, resulting in a smaller PNG image.
+*) btype: the block type for LZ77.
+ 0 = uncompressed, 1 = fixed huffman tree, 2 = dynamic huffman tree (best compression)
+*) useLZ77: whether or not to use LZ77 for compressed block types
+*) windowSize: the window size used by the LZ77 encoder (1 - 32768)
+*) force_palette: if colorType is 2 or 6, you can make the encoder write a PLTE
+ chunk if force_palette is true. This can used as suggested palette to convert
+ to by viewers that don't support more than 256 colors (if those still exist)
+*) add_id: add text chunk "Encoder: LodePNG <version>" to the image.
+*) text_compression: default 0. If 1, it'll store texts as zTXt instead of tEXt chunks.
+ zTXt chunks use zlib compression on the text. This gives a smaller result on
+ large texts but a larger result on small texts (such as a single program name).
+ It's all tEXt or all zTXt though, there's no separate setting per text yet.
+
+
+6. color conversions
+--------------------
+
+In LodePNG, the color mode (bits, channels and palette) used in the PNG image,
+and the color mode used in the raw data, are separate and independently
+configurable. Therefore, LodePNG needs to do conversions from one color mode to
+another. Not all possible conversions are supported (e.g. converting to a palette
+or a lower bit depth isn't supported). This section will explain which conversions
+are supported and how to configure this. This explains for example when LodePNG
+uses the settings in LodePNG_InfoPng, LodePNG_InfoRaw and Settings.
+
+6.1. PNG color types
+--------------------
+
+A PNG image can have many color types, ranging from 1-bit color to 64-bit color,
+as well as palettized color modes. After the zlib decompression and unfiltering
+in the PNG image is done, the raw pixel data will have that color type and thus
+a certain amount of bits per pixel. If you want the output raw image after
+decoding to have another color type, a conversion is done by LodePNG.
+
+The PNG specification mentions the following color types:
+
+0: greyscale, bit depths 1, 2, 4, 8, 16
+2: RGB, bit depths 8 and 16
+3: palette, bit depths 1, 2, 4 and 8
+4: greyscale with alpha, bit depths 8 and 16
+6: RGBA, bit depths 8 and 16
+
+Bit depth is the amount of bits per pixel per color channel. So the total amount
+of bits per pixel = amount of channels * bitDepth.
+
+6.2. Default Behaviour of LodePNG
+---------------------------------
+
+By default, the Decoder will convert the data from the PNG to 32-bit RGBA color,
+no matter what color type the PNG has, so that the result can be used directly
+as a texture in OpenGL etc... without worries about what color type the original
+image has.
+
+The Encoder assumes by default that the raw input you give it is a 32-bit RGBA
+buffer and will store the PNG as either 32 bit or 24 bit depending on whether
+or not any translucent pixels were detected in it.
+
+To get the default behaviour, don't change the values of LodePNG_InfoRaw and
+LodePNG_InfoPng of the encoder, and don't change the values of LodePNG_InfoRaw
+of the decoder.
+
+6.3. Color Conversions
+----------------------
+
+As explained in the sections about the Encoder and Decoder, you can specify
+color types and bit depths in LodePNG_InfoPng and LodePNG_InfoRaw, to change the default behaviour
+explained above. (for the Decoder you can only specify the LodePNG_InfoRaw, because the
+LodePNG_InfoPng contains what the PNG file has).
+
+To avoid some confusion:
+-the Decoder converts from PNG to raw image
+-the Encoder converts from raw image to PNG
+-the color type and bit depth in LodePNG_InfoRaw, are those of the raw image
+-the color type and bit depth in LodePNG_InfoPng, are those of the PNG
+-if the color type of the LodePNG_InfoRaw and PNG image aren't the same, a conversion
+between the color types is done if the color types are supported. If it is not
+supported, an error is returned. If the types are the same, no conversion is done
+and this is supported for any color type.
+
+Supported color conversions:
+-It's possible to load PNGs from any colortype and to save PNGs of any colorType.
+-Both encoder and decoder use the same converter. So both encoder and decoder
+suport the same color types at the input and the output. So the decoder supports
+any type of PNG image and can convert it to certain types of raw image, while the
+encoder supports any type of raw data but only certain color types for the output PNG.
+-The converter can convert from _any_ input color type, to 24-bit RGB or 32-bit RGBA (8 bits per channel)
+-The converter can convert from _any_ input color type, to 48-bit RGB or 64-bit RGBA (16 bits per channel)
+-The converter can convert from greyscale input color type, to 8-bit greyscale or greyscale with alpha
+-The converter can convert from greyscale input color type, to 16-bit greyscale or greyscale with alpha
+-If both color types are the same, conversion from anything to anything is possible
+-Color types that are invalid according to the PNG specification are not allowed
+-When converting from a type with alpha channel to one without, the alpha channel information is discarded
+-When converting from a type without alpha channel to one with, the result will be opaque except
+ pixels that have the same color as the color key of the input if one was given
+-When converting from 16-bit bitDepth to 8-bit bitDepth, the 16-bit precision information is lost,
+ only the most significant byte is kept
+-When converting from 8-bit bitDepth to 16-bit bitDepth, the 8-bit byte is duplicated, so that 0 stays 0, and
+ the 8-bit maximum 255 is converted to the 16-bit maximum 65535. Something similar happens at bit level for
+ converting very low bit depths to 8 or 16 bit.
+-Converting from color to greyscale or to palette is not supported on purpose: there are multiple possible
+ algorithms to do this color reduction, LodePNG does not want to pick one and leaves this choice to the
+ user instead, because it's beyond the scope of PNG encoding.
+-Converting from a palette to a palette, only keeps the indices, it ignores the colors defined in the
+ palette without giving an error
+
+No conversion needed...:
+-If the color type of the PNG image and raw image are the same, then no
+conversion is done, and all color types are supported.
+-In the encoder, you can make it save a PNG with any color by giving the
+LodePNG_InfoRaw and LodePNG_InfoPng the same color type.
+-In the decoder, you can make it store the pixel data in the same color type
+as the PNG has, by setting the color_convert setting to false. Settings in
+infoRaw are then ignored.
+
+The function LodePNG_convert does this, which is available in the interface but
+normally isn't needed since the encoder and decoder already call it.
+
+6.4. More Notes
+---------------
+
+In the PNG file format, if a less than 8-bit per pixel color type is used and the scanlines
+have a bit amount that isn't a multiple of 8, then padding bits are used so that each
+scanline starts at a fresh byte. But that is NOT true for the LodePNG input and output!
+The raw input image you give to the encoder, and the raw output image you get from the decoder
+will NOT have these padding bits, e.g. in the case of a 1-bit image with a width
+of 7 pixels, the first pixel of the second scanline will the the 8th bit of the first byte,
+not the first bit of a new byte.
+
+7. error values
+---------------
+
+All functions in LodePNG that return an error code, return 0 if everything went
+OK, or one of the code defined by LodePNG if there was an error.
+
+The meaning of the LodePNG error values can be retrieved with the function
+LodePNG_error_text: given the numerical error code, it returns a description
+of the error in English as a string.
+
+Check the implementation of LodePNG_error_text to see the meaning of each error code.
+
+
+8. chunks and PNG editing
+-------------------------
+
+If you want to add extra chunks to a PNG you encode, or use LodePNG for a PNG
+editor that should follow the rules about handling of unknown chunks, or if you
+program is able to read other types of chunks than the ones handled by LodePNG,
+then that's possible with the chunk functions of LodePNG.
+
+A PNG chunk has the following layout:
+
+4 bytes length
+4 bytes type name
+length bytes data
+4 bytes CRC
+
+
+8.1. iterating through chunks
+-----------------------------
+
+If you have a buffer containing the PNG image data, then the first chunk (the
+IHDR chunk) starts at byte number 8 of that buffer. The first 8 bytes are the
+signature of the PNG and are not part of a chunk. But if you start at byte 8
+then you have a chunk, and can check the following things of it.
+
+NOTE: none of these functions check for memory buffer boundaries. To avoid
+exploits, always make sure the buffer contains all the data of the chunks.
+When using LodePNG_chunk_next, make sure the returned value is within the
+allocated memory.
+
+unsigned LodePNG_chunk_length(const unsigned char* chunk):
+
+Get the length of the chunk's data. The total chunk length is this length + 12.
+
+void LodePNG_chunk_type(char type[5], const unsigned char* chunk):
+unsigned char LodePNG_chunk_type_equals(const unsigned char* chunk, const char* type):
+
+Get the type of the chunk or compare if it's a certain type
+
+unsigned char LodePNG_chunk_critical(const unsigned char* chunk):
+unsigned char LodePNG_chunk_private(const unsigned char* chunk):
+unsigned char LodePNG_chunk_safetocopy(const unsigned char* chunk):
+
+Check if the chunk is critical in the PNG standard (only IHDR, PLTE, IDAT and IEND are).
+Check if the chunk is private (public chunks are part of the standard, private ones not).
+Check if the chunk is safe to copy. If it's not, then, when modifying data in a critical
+chunk, unsafe to copy chunks of the old image may NOT be saved in the new one if your
+program doesn't handle that type of unknown chunk.
+
+unsigned char* LodePNG_chunk_data(unsigned char* chunk):
+const unsigned char* LodePNG_chunk_data_const(const unsigned char* chunk):
+
+Get a pointer to the start of the data of the chunk.
+
+unsigned LodePNG_chunk_check_crc(const unsigned char* chunk):
+void LodePNG_chunk_generate_crc(unsigned char* chunk):
+
+Check if the crc is correct or generate a correct one.
+
+unsigned char* LodePNG_chunk_next(unsigned char* chunk):
+const unsigned char* LodePNG_chunk_next_const(const unsigned char* chunk):
+
+Iterate to the next chunk. This works if you have a buffer with consecutive chunks. Note that these
+functions do no boundary checking of the allocated data whatsoever, so make sure there is enough
+data available in the buffer to be able to go to the next chunk.
+
+unsigned LodePNG_append_chunk(unsigned char** out, size_t* outlength, const unsigned char* chunk):
+unsigned LodePNG_create_chunk(unsigned char** out, size_t* outlength, unsigned length,
+ const char* type, const unsigned char* data):
+
+These functions are used to create new chunks that are appended to the data in *out that has
+length *outlength. The append function appends an existing chunk to the new data. The create
+function creates a new chunk with the given parameters and appends it. Type is the 4-letter
+name of the chunk.
+
+
+8.2. chunks in infoPng
+----------------------
+
+The LodePNG_InfoPng struct contains a struct LodePNG_UnknownChunks in it. This
+struct has 3 buffers (each with size) to contain 3 types of unknown chunks:
+the ones that come before the PLTE chunk, the ones that come between the PLTE
+and the IDAT chunks, and the ones that come after the IDAT chunks.
+It's necessary to make the distionction between these 3 cases because the PNG
+standard forces to keep the ordering of unknown chunks compared to the critical
+chunks, but does not force any other ordering rules.
+
+infoPng.unknown_chunks.data[0] is the chunks before PLTE
+infoPng.unknown_chunks.data[1] is the chunks after PLTE, before IDAT
+infoPng.unknown_chunks.data[2] is the chunks after IDAT
+
+The chunks in these 3 buffers can be iterated through and read by using the same
+way described in the previous subchapter.
+
+When using the decoder to decode a PNG, you can make it store all unknown chunks
+if you set the option settings.rememberUnknownChunks to 1. By default, this option
+is off and is 0.
+
+The encoder will always encode unknown chunks that are stored in the infoPng. If
+you need it to add a particular chunk that isn't known by LodePNG, you can use
+LodePNG_append_chunk or LodePNG_create_chunk to the chunk data in
+infoPng.unknown_chunks.data[x].
+
+Chunks that are known by LodePNG should not be added in that way. E.g. to make
+LodePNG add a bKGD chunk, set background_defined to true and add the correct
+parameters there and LodePNG will generate the chunk.
+
+
+9. compiler support
+-------------------
+
+No libraries other than the current standard C library are needed to compile
+LodePNG. For the C++ version, only the standard C++ library is needed on top.
+Add the files lodepng.c(pp) and lodepng.h to your project, include
+lodepng.h where needed, and your program can read/write PNG files.
+
+Use optimization! For both the encoder and decoder, compiling with the best
+optimizations makes a large difference.
+
+Make sure that LodePNG is compiled with the same compiler of the same version
+and with the same settings as the rest of the program, or the interfaces with
+std::vectors and std::strings in C++ can be incompatible resulting in bad things.
+
+CHAR_BITS must be 8 or higher, because LodePNG uses unsigned chars for octets.
+
+*) gcc and g++
+
+LodePNG is developed in gcc so this compiler is natively supported. It gives no
+warnings with compiler options "-Wall -Wextra -pedantic -ansi", with gcc and g++
+version 4.5.1 on Linux.
+
+*) Mingw and Bloodshed DevC++
+
+The Mingw compiler (a port of gcc) used by Bloodshed DevC++ for Windows is fully
+supported by LodePNG.
+
+*) Visual Studio 2005 and Visual C++ 2005 Express Edition
+
+Versions 20070604 up to 20080107 have been tested on VS2005 and work. Visual
+studio may give warnings about 'fopen' being deprecated. A multiplatform library
+can't support the proposed Visual Studio alternative however.
+
+If you're using LodePNG in VS2005 and don't want to see the deprecated warnings,
+put this on top of lodepng.h before the inclusions: #define _CRT_SECURE_NO_DEPRECATE
+
+*) Visual Studio 6.0
+
+The C++ version of LodePNG was not supported by Visual Studio 6.0 because Visual
+Studio 6.0 doesn't follow the C++ standard and implements it incorrectly.
+The current C version of LodePNG has not been tested in VS6 but may work now.
+
+*) Comeau C/C++
+
+Vesion 20070107 compiles without problems on the Comeau C/C++ Online Test Drive
+at http://www.comeaucomputing.com/tryitout in both C90 and C++ mode.
+
+*) Compilers on Macintosh
+
+LodePNG has been reported to work both with the gcc and LLVM for Macintosh, both
+for C and C++.
+
+*) Other Compilers
+
+If you encounter problems on other compilers, I'm happy to help out make LodePNG
+support the compiler if it supports the ISO C90 and C++ standard well enough and
+the required modification doesn't require using non standard or less good C/C++
+code or headers.
+
+
+10. examples
+------------
+
+This decoder and encoder example show the most basic usage of LodePNG (using the
+classes, not the simple functions, which would be trivial)
+
+More complex examples can be found in:
+-lodepng_examples.c: 9 different examples in C, such as showing the image with SDL, ...
+-lodepng_examples.cpp: the same examples in C++ using the C++ wrapper of LodePNG
+
+These files can be found on the LodePNG website or searched for on the internet.
+
+10.1. decoder C++ example
+-------------------------
+
+////////////////////////////////////////////////////////////////////////////////
+#include "lodepng.h"
+#include <iostream>
+
+int main(int argc, char *argv[])
+{
+ const char* filename = argc > 1 ? argv[1] : "test.png";
+
+ //load and decode
+ std::vector<unsigned char> buffer, image; //buffer will contain the PNG file, image will contain the raw pixels
+ LodePNG::loadFile(buffer, filename); //load the image file with given filename
+ LodePNG::Decoder decoder;
+ decoder.decode(image, buffer.size() ? &buffer[0] : 0, (unsigned)buffer.size()); //decode the png
+
+ //if there's an error, display it
+ if(decoder.hasError())
+ std::cout << "error " << decoder.getError() << ": "<< LodePNG_error_text(decoder.getError()) << std::endl;
+
+ int width = decoder.getWidth(); //get the width in pixels
+ int height = decoder.getHeight(); //get the height in pixels
+ //the pixels are now in the vector "image", 4 bytes per pixel, ordered RGBARGBA..., use it as texture, draw it, ...
+}
+
+//alternative version using the "simple" function
+int main(int argc, char *argv[])
+{
+ const char* filename = argc > 1 ? argv[1] : "test.png";
+
+ //load and decode
+ std::vector<unsigned char> image;
+ unsigned width, height;
+ unsigned error = LodePNG::decode(image, width, height, filename);
+
+ //if there's an error, display it
+ if(error != 0) std::cout << "error " << error << ": " << LodePNG_error_text(error) << std::endl;
+
+ //the pixels are now in the vector "image", 4 bytes per pixel, ordered RGBARGBA..., use it as texture, draw it, ...
+}
+////////////////////////////////////////////////////////////////////////////////
+
+
+10.2. encoder C++ example
+-------------------------
+
+////////////////////////////////////////////////////////////////////////////////
+#include "lodepng.h"
+#include <iostream>
+
+//saves image to filename given as argument. Warning, this overwrites the file without warning!
+int main(int argc, char *argv[])
+{
+ //check if user gave a filename
+ if(argc <= 1)
+ {
+ std::cout << "please provide a filename to save to\n";
+ return 0;
+ }
+
+ //generate some image
+ std::vector<unsigned char> image;
+ image.resize(512 * 512 * 4);
+ for(unsigned y = 0; y < 512; y++)
+ for(unsigned x = 0; x < 512; x++)
+ {
+ image[4 * 512 * y + 4 * x + 0] = 255 * !(x & y);
+ image[4 * 512 * y + 4 * x + 1] = x ^ y;
+ image[4 * 512 * y + 4 * x + 2] = x | y;
+ image[4 * 512 * y + 4 * x + 3] = 255;
+ }
+
+ //encode and save, using the Encoder class
+ std::vector<unsigned char> buffer;
+ LodePNG::Encoder encoder;
+ encoder.encode(buffer, image, 512, 512);
+ LodePNG::saveFile(buffer, argv[1]);
+
+ //the same as the 4 lines of code above, but in 1 call without the class:
+ //LodePNG::encode(argv[1], image, 512, 512);
+}
+////////////////////////////////////////////////////////////////////////////////
+
+
+10.3. Decoder C example
+-----------------------
+
+This example loads the PNG from a file into a pixel buffer in 1 function call
+
+#include "lodepng.h"
+
+int main(int argc, char *argv[])
+{
+ unsigned error;
+ unsigned char* image;
+ size_t width, height;
+
+ if(argc <= 1) return 0;
+
+ error = LodePNG_decode32_file(&image, &width, &height, filename);
+
+ if(error != 0) printf("error %u: %s\n", error, LodePNG_error_text(error));
+
+ //use image here
+
+ free(image);
+}
+
+
+11. changes
+-----------
+
+The version number of LodePNG is the date of the change given in the format
+yyyymmdd.
+
+Some changes aren't backwards compatible. Those are indicated with a (!)
+symbol.
+
+*) 8 sep 2011: lz77 encoder lazy matching instead of greedy matching.
+*) 23 aug 2011: tweaked the zlib compression parameters after benchmarking.
+ A bug with the PNG filtertype heuristic was fixed, so that it chooses much
+ better ones (it's quite significant). A setting to do an experimental, slow,
+ brute force search for PNG filter types is added.
+*) 17 aug 2011 (!): changed some C zlib related function names.
+*) 16 aug 2011: made the code less wide (max 120 characters per line).
+*) 17 apr 2011: code cleanup. Bugfixes. Convert low to 16-bit per sample colors.
+*) 21 feb 2011: fixed compiling for C90. Fixed compiling with sections disabled.
+*) 11 dec 2010: encoding is made faster, based on suggestion by Peter Eastman
+ to optimize long sequences of zeros.
+*) 13 nov 2010: added LodePNG_InfoColor_hasPaletteAlpha and
+ LodePNG_InfoColor_canHaveAlpha functions for convenience.
+*) 7 nov 2010: added LodePNG_error_text function to get error code description.
+*) 30 okt 2010: made decoding slightly faster
+*) 26 okt 2010: (!) changed some C function and struct names (more consistent).
+ Reorganized the documentation and the declaration order in the header.
+*) 08 aug 2010: only changed some comments and external samples.
+*) 05 jul 2010: fixed bug thanks to warnings in the new gcc version.
+*) 14 mar 2010: fixed bug where too much memory was allocated for char buffers.
+*) 02 sep 2008: fixed bug where it could create empty tree that linux apps could
+ read by ignoring the problem but windows apps couldn't.
+*) 06 jun 2008: added more error checks for out of memory cases.
+*) 26 apr 2008: added a few more checks here and there to ensure more safety.
+*) 06 mar 2008: crash with encoding of strings fixed
+*) 02 feb 2008: support for international text chunks added (iTXt)
+*) 23 jan 2008: small cleanups, and #defines to divide code in sections
+*) 20 jan 2008: support for unknown chunks allowing using LodePNG for an editor.
+*) 18 jan 2008: support for tIME and pHYs chunks added to encoder and decoder.
+*) 17 jan 2008: ability to encode and decode compressed zTXt chunks added
+ Also vareous fixes, such as in the deflate and the padding bits code.
+*) 13 jan 2008: Added ability to encode Adam7-interlaced images. Improved
+ filtering code of encoder.
+*) 07 jan 2008: (!) changed LodePNG to use ISO C90 instead of C++. A
+ C++ wrapper around this provides an interface almost identical to before.
+ Having LodePNG be pure ISO C90 makes it more portable. The C and C++ code
+ are together in these files but it works both for C and C++ compilers.
+*) 29 dec 2007: (!) changed most integer types to unsigned int + other tweaks
+*) 30 aug 2007: bug fixed which makes this Borland C++ compatible
+*) 09 aug 2007: some VS2005 warnings removed again
+*) 21 jul 2007: deflate code placed in new namespace separate from zlib code
+*) 08 jun 2007: fixed bug with 2- and 4-bit color, and small interlaced images
+*) 04 jun 2007: improved support for Visual Studio 2005: crash with accessing
+ invalid std::vector element [0] fixed, and level 3 and 4 warnings removed
+*) 02 jun 2007: made the encoder add a tag with version by default
+*) 27 may 2007: zlib and png code separated (but still in the same file),
+ simple encoder/decoder functions added for more simple usage cases
+*) 19 may 2007: minor fixes, some code cleaning, new error added (error 69),
+ moved some examples from here to lodepng_examples.cpp
+*) 12 may 2007: palette decoding bug fixed
+*) 24 apr 2007: changed the license from BSD to the zlib license
+*) 11 mar 2007: very simple addition: ability to encode bKGD chunks.
+*) 04 mar 2007: (!) tEXt chunk related fixes, and support for encoding
+ palettized PNG images. Plus little interface change with palette and texts.
+*) 03 mar 2007: Made it encode dynamic Huffman shorter with repeat codes.
+ Fixed a bug where the end code of a block had length 0 in the Huffman tree.
+*) 26 feb 2007: Huffman compression with dynamic trees (BTYPE 2) now implemented
+ and supported by the encoder, resulting in smaller PNGs at the output.
+*) 27 jan 2007: Made the Adler-32 test faster so that a timewaste is gone.
+*) 24 jan 2007: gave encoder an error interface. Added color conversion from any
+ greyscale type to 8-bit greyscale with or without alpha.
+*) 21 jan 2007: (!) Totally changed the interface. It allows more color types
+ to convert to and is more uniform. See the manual for how it works now.
+*) 07 jan 2007: Some cleanup & fixes, and a few changes over the last days:
+ encode/decode custom tEXt chunks, separate classes for zlib & deflate, and
+ at last made the decoder give errors for incorrect Adler32 or Crc.
+*) 01 jan 2007: Fixed bug with encoding PNGs with less than 8 bits per channel.
+*) 29 dec 2006: Added support for encoding images without alpha channel, and
+ cleaned out code as well as making certain parts faster.
+*) 28 dec 2006: Added "Settings" to the encoder.
+*) 26 dec 2006: The encoder now does LZ77 encoding and produces much smaller files now.
+ Removed some code duplication in the decoder. Fixed little bug in an example.
+*) 09 dec 2006: (!) Placed output parameters of public functions as first parameter.
+ Fixed a bug of the decoder with 16-bit per color.
+*) 15 okt 2006: Changed documentation structure
+*) 09 okt 2006: Encoder class added. It encodes a valid PNG image from the
+ given image buffer, however for now it's not compressed.
+*) 08 sep 2006: (!) Changed to interface with a Decoder class
+*) 30 jul 2006: (!) LodePNG_InfoPng , width and height are now retrieved in different
+ way. Renamed decodePNG to decodePNGGeneric.
+*) 29 jul 2006: (!) Changed the interface: image info is now returned as a
+ struct of type LodePNG::LodePNG_Info, instead of a vector, which was a bit clumsy.
+*) 28 jul 2006: Cleaned the code and added new error checks.
+ Corrected terminology "deflate" into "inflate".
+*) 23 jun 2006: Added SDL example in the documentation in the header, this
+ example allows easy debugging by displaying the PNG and its transparency.
+*) 22 jun 2006: (!) Changed way to obtain error value. Added
+ loadFile function for convenience. Made decodePNG32 faster.
+*) 21 jun 2006: (!) Changed type of info vector to unsigned.
+ Changed position of palette in info vector. Fixed an important bug that
+ happened on PNGs with an uncompressed block.
+*) 16 jun 2006: Internally changed unsigned into unsigned where
+ needed, and performed some optimizations.
+*) 07 jun 2006: (!) Renamed functions to decodePNG and placed them
+ in LodePNG namespace. Changed the order of the parameters. Rewrote the
+ documentation in the header. Renamed files to lodepng.cpp and lodepng.h
+*) 22 apr 2006: Optimized and improved some code
+*) 07 sep 2005: (!) Changed to std::vector interface
+*) 12 aug 2005: Initial release (C++, decoder only)
+
+
+12. contact information
+-----------------------
+
+Feel free to contact me with suggestions, problems, comments, ... concerning
+LodePNG. If you encounter a PNG image that doesn't work properly with this
+decoder, feel free to send it and I'll use it to find and fix the problem.
+
+My email address is (puzzle the account and domain together with an @ symbol):
+Domain: gmail dot com.
+Account: lode dot vandevenne.
+
+
+Copyright (c) 2005-2011 Lode Vandevenne
+*/
+
+#endif
+
contact: Jan Huwald // Impressum