Mercurial > sdl-ios-xcode
view test/testbitmap.c @ 638:b0108e9dea53
Date: Sun, 11 May 2003 19:59:06 +0300
From: Pasi K?rkk?inen
Subject: [PATCH] fix SDL OpenGL segfault with DRI/Mesa drivers and Glew
Hello!
The attached patch fixes a bug in SDL which causes SDL to crash in
X11_GL_Shutdown() if you are using DRI/Mesa drivers AND glew
(http://glew.sf.net).
The bug is caused by a namespace collision affecting dlsym() to fetch wrong
pointer for glXReleaseBuffersMESA() (uninitialized pointer from glew because
the extension is NOT supported by the driver) and then SDL calling it in
X11_GL_Shutdown().
SDL should check if the glXReleaseBuffersMESA() is really supported by the
driver (from the extensions string) before calling it.
Attached patch adds extension string parsing to check if
glXReleaseBuffersMESA() is really supported (and this way
prevents the segfault).
Availability of the extensions should be _always_ checked from the
extensions string rather than using dlsym()!
Please add it to the next version of SDL.
Thanks to gltron and author of glew to help fixing this.
author | Sam Lantinga <slouken@libsdl.org> |
---|---|
date | Sat, 28 Jun 2003 17:27:33 +0000 |
parents | 74212992fb08 |
children | 609543e2b3a1 |
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line source
/* Simple program: Test bitmap blits */ #include <stdio.h> #include <stdlib.h> #include <string.h> #include "SDL.h" #include "picture.xbm" SDL_Surface *LoadXBM(SDL_Surface *screen, int w, int h, Uint8 *bits) { SDL_Surface *bitmap; Uint8 *line; /* Allocate the bitmap */ bitmap = SDL_CreateRGBSurface(SDL_SWSURFACE, w, h, 1, 0, 0, 0, 0); if ( bitmap == NULL ) { fprintf(stderr, "Couldn't allocate bitmap: %s\n", SDL_GetError()); return(NULL); } /* Copy the pixels */ line = (Uint8 *)bitmap->pixels; w = (w+7)/8; while ( h-- ) { memcpy(line, bits, w); /* X11 Bitmap images have the bits reversed */ { int i, j; Uint8 *buf, byte; for ( buf=line, i=0; i<w; ++i, ++buf ) { byte = *buf; *buf = 0; for ( j=7; j>=0; --j ) { *buf |= (byte&0x01)<<j; byte >>= 1; } } } line += bitmap->pitch; bits += w; } return(bitmap); } int main(int argc, char *argv[]) { SDL_Surface *screen; SDL_Surface *bitmap; Uint8 video_bpp; Uint32 videoflags; Uint8 *buffer; int i, done; SDL_Event event; /* Initialize SDL */ if ( SDL_Init(SDL_INIT_VIDEO) < 0 ) { fprintf(stderr, "Couldn't initialize SDL: %s\n",SDL_GetError()); exit(1); } atexit(SDL_Quit); video_bpp = 0; videoflags = SDL_SWSURFACE; while ( argc > 1 ) { --argc; if ( strcmp(argv[argc-1], "-bpp") == 0 ) { video_bpp = atoi(argv[argc]); --argc; } else if ( strcmp(argv[argc], "-warp") == 0 ) { videoflags |= SDL_HWPALETTE; } else if ( strcmp(argv[argc], "-hw") == 0 ) { videoflags |= SDL_HWSURFACE; } else if ( strcmp(argv[argc], "-fullscreen") == 0 ) { videoflags |= SDL_FULLSCREEN; } else { fprintf(stderr, "Usage: %s [-bpp N] [-warp] [-hw] [-fullscreen]\n", argv[0]); exit(1); } } /* Set 640x480 video mode */ if ( (screen=SDL_SetVideoMode(640,480,video_bpp,videoflags)) == NULL ) { fprintf(stderr, "Couldn't set 640x480x%d video mode: %s\n", video_bpp, SDL_GetError()); exit(2); } /* Set the surface pixels and refresh! */ if ( SDL_LockSurface(screen) < 0 ) { fprintf(stderr, "Couldn't lock the display surface: %s\n", SDL_GetError()); exit(2); } buffer=(Uint8 *)screen->pixels; for ( i=0; i<screen->h; ++i ) { memset(buffer,(i*255)/screen->h, screen->pitch); buffer += screen->pitch; } SDL_UnlockSurface(screen); SDL_UpdateRect(screen, 0, 0, 0, 0); /* Load the bitmap */ bitmap = LoadXBM(screen, picture_width, picture_height, (Uint8 *)picture_bits); if ( bitmap == NULL ) { exit(1); } /* Wait for a keystroke */ done = 0; while ( !done ) { /* Check for events */ while ( SDL_PollEvent(&event) ) { switch (event.type) { case SDL_MOUSEBUTTONDOWN: { SDL_Rect dst; dst.x = event.button.x - bitmap->w/2; dst.y = event.button.y - bitmap->h/2; dst.w = bitmap->w; dst.h = bitmap->h; SDL_BlitSurface(bitmap, NULL, screen, &dst); SDL_UpdateRects(screen,1,&dst); } break; case SDL_KEYDOWN: /* Any key press quits the app... */ done = 1; break; case SDL_QUIT: done = 1; break; default: break; } } } SDL_FreeSurface(bitmap); return(0); }