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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/OffscreenContextGLX.cc
parent1bec7aad09631d3f86874ead2c26335bc897fde5 (diff)
add files removed from test path
Diffstat (limited to 'src/OffscreenContextGLX.cc')
-rw-r--r--src/OffscreenContextGLX.cc328
1 files changed, 328 insertions, 0 deletions
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);
+}
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