diff options
author | don bright <hugh.m.bright@gmail.com> | 2013-01-24 03:02:31 (GMT) |
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committer | don bright <hugh.m.bright@gmail.com> | 2013-01-24 03:02:31 (GMT) |
commit | 1e7636e364535c78e4eebd36666bac5d352c3608 (patch) | |
tree | 5479c9229973795a771f912f3c3414f2075f2875 /src/OffscreenContextGLX.cc | |
parent | 1bec7aad09631d3f86874ead2c26335bc897fde5 (diff) |
add files removed from test path
Diffstat (limited to 'src/OffscreenContextGLX.cc')
-rw-r--r-- | src/OffscreenContextGLX.cc | 328 |
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); +} |