view test/testwin.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 153f221b7d48
children be9c9c8f6d53
line wrap: on
line source


/* Bring up a window and play with it */

#include <stdlib.h>
#include <stdio.h>
#include <string.h>

#define BENCHMARK_SDL

#define NOTICE(X)	printf("%s", X);

#include "SDL.h"

void DrawPict(SDL_Surface *screen, char *bmpfile,
					int speedy, int flip, int nofade)
{
	SDL_Surface *picture;
	SDL_Rect dest, update;
	int i, centered;
	int ncolors;
	SDL_Color *colors, *cmap;

	/* Load the image into a surface */
	if ( bmpfile == NULL ) {
		bmpfile = "sample.bmp";		/* Sample image */
	}
fprintf(stderr, "Loading picture: %s\n", bmpfile);
	picture = SDL_LoadBMP(bmpfile);
	if ( picture == NULL ) {
		fprintf(stderr, "Couldn't load %s: %s\n", bmpfile,
							SDL_GetError());
		return;
	}

	/* Set the display colors -- on a hicolor display this is a no-op */
	if ( picture->format->palette ) {
		ncolors = picture->format->palette->ncolors;
		colors  = (SDL_Color *)malloc(ncolors*sizeof(SDL_Color));
		cmap    = (SDL_Color *)malloc(ncolors*sizeof(SDL_Color));
		memcpy(colors, picture->format->palette->colors,
						ncolors*sizeof(SDL_Color));
	} else {
		int       r, g, b;

		/* Allocate 256 color palette */
		ncolors = 256;
		colors  = (SDL_Color *)malloc(ncolors*sizeof(SDL_Color));
		cmap    = (SDL_Color *)malloc(ncolors*sizeof(SDL_Color));

		/* Set a 3,3,2 color cube */
		for ( r=0; r<8; ++r ) {
			for ( g=0; g<8; ++g ) {
				for ( b=0; b<4; ++b ) {
					i = ((r<<5)|(g<<2)|b);
					colors[i].r = r<<5;
					colors[i].g = g<<5;
					colors[i].b = b<<6;
				}
			}
		}
	}
NOTICE("testwin: setting colors\n");
	if ( ! SDL_SetColors(screen, colors, 0, ncolors) &&
				(screen->format->palette != NULL) ) {
		fprintf(stderr,
"Warning: Couldn't set all of the colors, but SDL will map the image\n"
"         (colormap fading will suffer - try the -warp option)\n"
		);
	}

	/* Set the screen to black (not really necessary) */
	if ( SDL_LockSurface(screen) == 0 ) {
		Uint32 black;
		Uint8 *pixels;

		black = SDL_MapRGB(screen->format, 0, 0, 0);
		pixels = (Uint8 *)screen->pixels;
		for ( i=0; i<screen->h; ++i ) {
			memset(pixels, black,
				screen->w*screen->format->BytesPerPixel);
			pixels += screen->pitch;
		}
		SDL_UnlockSurface(screen);
		SDL_UpdateRect(screen, 0, 0, 0, 0);
	}
	
	/* Display the picture */
	if ( speedy ) {
		SDL_Surface *displayfmt;

fprintf(stderr, "Converting picture\n");
		displayfmt = SDL_DisplayFormat(picture);
		if ( displayfmt == NULL ) {
			fprintf(stderr,
				"Couldn't convert image: %s\n", SDL_GetError());
			goto done;
		}
		SDL_FreeSurface(picture);
		picture = displayfmt;
	}
	printf("(image surface located in %s memory)\n", 
			(picture->flags&SDL_HWSURFACE) ? "video" : "system");
	centered = (screen->w - picture->w)/2;
	if ( centered < 0 ) {
		centered = 0;
	}
	dest.y = (screen->h - picture->h)/2;
	dest.w = picture->w;
	dest.h = picture->h;
NOTICE("testwin: moving image\n");
	for ( i=0; i<=centered; ++i ) {
		dest.x = i;
		update = dest;
		if ( SDL_BlitSurface(picture, NULL, screen, &update) < 0 ) {
			fprintf(stderr, "Blit failed: %s\n", SDL_GetError());
			break;
		}
		if ( flip ) {
			SDL_Flip(screen);
		} else {
			SDL_UpdateRects(screen, 1, &update);
		}
	}

#ifdef SCREENSHOT
	if ( SDL_SaveBMP(screen, "screen.bmp") < 0 )
		printf("Couldn't save screen: %s\n", SDL_GetError());
#endif

#ifndef BENCHMARK_SDL
	/* Let it sit there for a while */
	SDL_Delay(5*1000);
#endif
	/* Fade the colormap */
	if ( ! nofade ) {
		int maxstep;
		SDL_Color final;
		SDL_Color palcolors[256];
		struct {
			Sint16 r, g, b;
		} cdist[256];

NOTICE("testwin: fading out...\n");
		memcpy(cmap, colors, ncolors*sizeof(SDL_Color));
		maxstep = 32-1;
		final.r = 0xFF;
		final.g = 0x00;
		final.b = 0x00;
		memcpy(palcolors, colors, ncolors*sizeof(SDL_Color));
		for ( i=0; i<ncolors; ++i ) {
			cdist[i].r = final.r-palcolors[i].r;
			cdist[i].g = final.g-palcolors[i].g;
			cdist[i].b = final.b-palcolors[i].b;
		}
		for ( i=0; i<=maxstep/2; ++i ) {	/* halfway fade */
			int c;
			for ( c=0; c<ncolors; ++c ) {
				colors[c].r =
					palcolors[c].r+((cdist[c].r*i))/maxstep;
				colors[c].g =
					palcolors[c].g+((cdist[c].g*i))/maxstep;
				colors[c].b =
					palcolors[c].b+((cdist[c].b*i))/maxstep;
			}
			SDL_SetColors(screen, colors, 0, ncolors);
			SDL_Delay(1);
		}
		final.r = 0x00;
		final.g = 0x00;
		final.b = 0x00;
		memcpy(palcolors, colors, ncolors*sizeof(SDL_Color));
		for ( i=0; i<ncolors; ++i ) {
			cdist[i].r = final.r-palcolors[i].r;
			cdist[i].g = final.g-palcolors[i].g;
			cdist[i].b = final.b-palcolors[i].b;
		}
		maxstep /= 2;
		for ( i=0; i<=maxstep; ++i ) {		/* finish fade out */
			int c;
			for ( c=0; c<ncolors; ++c ) {
				colors[c].r =
					palcolors[c].r+((cdist[c].r*i))/maxstep;
				colors[c].g =
					palcolors[c].g+((cdist[c].g*i))/maxstep;
				colors[c].b =
					palcolors[c].b+((cdist[c].b*i))/maxstep;
			}
			SDL_SetColors(screen, colors, 0, ncolors);
			SDL_Delay(1);
		}
		for ( i=0; i<ncolors; ++i ) {
			colors[i].r = final.r;
			colors[i].g = final.g;
			colors[i].b = final.b;
		}
		SDL_SetColors(screen, colors, 0, ncolors);
NOTICE("testwin: fading in...\n");
		memcpy(palcolors, colors, ncolors*sizeof(SDL_Color));
		for ( i=0; i<ncolors; ++i ) {
			cdist[i].r = cmap[i].r-palcolors[i].r;
			cdist[i].g = cmap[i].g-palcolors[i].g;
			cdist[i].b = cmap[i].b-palcolors[i].b;
		}
		for ( i=0; i<=maxstep; ++i ) {	/* 32 step fade in */
			int c;
			for ( c=0; c<ncolors; ++c ) {
				colors[c].r =
					palcolors[c].r+((cdist[c].r*i))/maxstep;
				colors[c].g =
					palcolors[c].g+((cdist[c].g*i))/maxstep;
				colors[c].b =
					palcolors[c].b+((cdist[c].b*i))/maxstep;
			}
			SDL_SetColors(screen, colors, 0, ncolors);
			SDL_Delay(1);
		}
NOTICE("testwin: fading over\n");
	}
	
done:
	/* Free the picture and return */
	SDL_FreeSurface(picture);
	free(colors); free(cmap);
	return;
}

int main(int argc, char *argv[])
{
	SDL_Surface *screen;
	/* Options */
	int speedy, flip, nofade;
	int delay;
	int w, h;
	int desired_bpp;
	Uint32 video_flags;
#ifdef BENCHMARK_SDL
	Uint32 then, now;
#endif
	/* Set default options and check command-line */
	speedy = 0;
	flip = 0;
	nofade = 0;
	delay = 1;
	w = 640;
	h = 480;
	desired_bpp = 0;
	video_flags = 0;
	while ( argc > 1 ) {
		if ( strcmp(argv[1], "-speedy") == 0 ) {
			speedy = 1;
			argv += 1;
			argc -= 1;
		} else
		if ( strcmp(argv[1], "-nofade") == 0 ) {
			nofade = 1;
			argv += 1;
			argc -= 1;
		} else
		if ( strcmp(argv[1], "-delay") == 0 ) {
			if ( argv[2] ) {
				delay = atoi(argv[2]);
				argv += 2;
				argc -= 2;
			} else {
				fprintf(stderr,
				"The -delay option requires an argument\n");
				exit(1);
			}
		} else
		if ( strcmp(argv[1], "-width") == 0 ) {
			if ( argv[2] && ((w = atoi(argv[2])) > 0) ) {
				argv += 2;
				argc -= 2;
			} else {
				fprintf(stderr,
				"The -width option requires an argument\n");
				exit(1);
			}
		} else
		if ( strcmp(argv[1], "-height") == 0 ) {
			if ( argv[2] && ((h = atoi(argv[2])) > 0) ) {
				argv += 2;
				argc -= 2;
			} else {
				fprintf(stderr,
				"The -height option requires an argument\n");
				exit(1);
			}
		} else
		if ( strcmp(argv[1], "-bpp") == 0 ) {
			if ( argv[2] ) {
				desired_bpp = atoi(argv[2]);
				argv += 2;
				argc -= 2;
			} else {
				fprintf(stderr,
				"The -bpp option requires an argument\n");
				exit(1);
			}
		} else
		if ( strcmp(argv[1], "-warp") == 0 ) {
			video_flags |= SDL_HWPALETTE;
			argv += 1;
			argc -= 1;
		} else
		if ( strcmp(argv[1], "-hw") == 0 ) {
			video_flags |= SDL_HWSURFACE;
			argv += 1;
			argc -= 1;
		} else
		if ( strcmp(argv[1], "-flip") == 0 ) {
			video_flags |= SDL_DOUBLEBUF;
			argv += 1;
			argc -= 1;
		} else
		if ( strcmp(argv[1], "-fullscreen") == 0 ) {
			video_flags |= SDL_FULLSCREEN;
			argv += 1;
			argc -= 1;
		} else
			break;
	}

	if ( SDL_Init(SDL_INIT_VIDEO) < 0 ) {
		fprintf(stderr,
			"Couldn't initialize SDL: %s\n", SDL_GetError());
		exit(1);
	}
	atexit(SDL_Quit);			/* Clean up on exit */

	/* Initialize the display */
	screen = SDL_SetVideoMode(w, h, desired_bpp, video_flags);
	if ( screen == NULL ) {
		fprintf(stderr, "Couldn't set %dx%dx%d video mode: %s\n",
					w, h, desired_bpp, SDL_GetError());
		exit(1);
	}
	printf("Set%s %dx%dx%d mode\n",
			screen->flags & SDL_FULLSCREEN ? " fullscreen" : "",
			screen->w, screen->h, screen->format->BitsPerPixel);
	printf("(video surface located in %s memory)\n",
			(screen->flags&SDL_HWSURFACE) ? "video" : "system");
	if ( screen->flags & SDL_DOUBLEBUF ) {
		printf("Double-buffering enabled\n");
		flip = 1;
	}

	/* Set the window manager title bar */
	SDL_WM_SetCaption("SDL test window", "testwin");

	/* Do all the drawing work */
#ifdef BENCHMARK_SDL
	then = SDL_GetTicks();
	DrawPict(screen, argv[1], speedy, flip, nofade);
	now = SDL_GetTicks();
	printf("Time: %d milliseconds\n", now-then);
#else
	DrawPict(screen, argv[1], speedy, flip, nofade);
#endif
	SDL_Delay(delay*1000);
	return(0);
}