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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 f6ffac90895c
children b8d311d90021
line wrap: on
line source

/*
    SDL - Simple DirectMedia Layer
    Copyright (C) 1997, 1998, 1999, 2000, 2001, 2002  Sam Lantinga

    This library is free software; you can redistribute it and/or
    modify it under the terms of the GNU Library General Public
    License as published by the Free Software Foundation; either
    version 2 of the License, or (at your option) any later version.

    This library is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
    Library General Public License for more details.

    You should have received a copy of the GNU Library General Public
    License along with this library; if not, write to the Free
    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA

    Sam Lantinga
    slouken@libsdl.org
*/

#ifdef SAVE_RCSID
static char rcsid =
 "@(#) $Id$";
#endif

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

#include "SDL_types.h"
#include "SDL_video.h"
#include "SDL_blit.h"

/* Functions to blit from bitmaps to other surfaces */

static void BlitBto1(SDL_BlitInfo *info)
{
	int c;
	int width, height;
	Uint8 *src, *map, *dst;
	int srcskip, dstskip;

	/* Set up some basic variables */
	width = info->d_width;
	height = info->d_height;
	src = info->s_pixels;
	srcskip = info->s_skip;
	dst = info->d_pixels;
	dstskip = info->d_skip;
	map = info->table;
	srcskip += width-(width+7)/8;

	if ( map ) {
		while ( height-- ) {
		        Uint8 byte = 0, bit;
	    		for ( c=0; c<width; ++c ) {
				if ( (c&7) == 0 ) {
					byte = *src++;
				}
				bit = (byte&0x80)>>7;
				if ( 1 ) {
				  *dst = map[bit];
				}
				dst++;
				byte <<= 1;
			}
			src += srcskip;
			dst += dstskip;
		}
	} else {
		while ( height-- ) {
		        Uint8 byte = 0, bit;
	    		for ( c=0; c<width; ++c ) {
				if ( (c&7) == 0 ) {
					byte = *src++;
				}
				bit = (byte&0x80)>>7;
				if ( 1 ) {
				  *dst = bit;
				}
				dst++;
				byte <<= 1;
			}
			src += srcskip;
			dst += dstskip;
		}
	}
}
static void BlitBto2(SDL_BlitInfo *info)
{
	int c;
	int width, height;
	Uint8 *src;
	Uint16 *map, *dst;
	int srcskip, dstskip;

	/* Set up some basic variables */
	width = info->d_width;
	height = info->d_height;
	src = info->s_pixels;
	srcskip = info->s_skip;
	dst = (Uint16 *)info->d_pixels;
	dstskip = info->d_skip/2;
	map = (Uint16 *)info->table;
	srcskip += width-(width+7)/8;

	while ( height-- ) {
	        Uint8 byte = 0, bit;
	    	for ( c=0; c<width; ++c ) {
			if ( (c&7) == 0 ) {
				byte = *src++;
			}
			bit = (byte&0x80)>>7;
			if ( 1 ) {
				*dst = map[bit];
			}
			byte <<= 1;
			dst++;
		}
		src += srcskip;
		dst += dstskip;
	}
}
static void BlitBto3(SDL_BlitInfo *info)
{
	int c, o;
	int width, height;
	Uint8 *src, *map, *dst;
	int srcskip, dstskip;

	/* Set up some basic variables */
	width = info->d_width;
	height = info->d_height;
	src = info->s_pixels;
	srcskip = info->s_skip;
	dst = info->d_pixels;
	dstskip = info->d_skip;
	map = info->table;
	srcskip += width-(width+7)/8;

	while ( height-- ) {
	        Uint8 byte = 0, bit;
	    	for ( c=0; c<width; ++c ) {
			if ( (c&7) == 0 ) {
				byte = *src++;
			}
			bit = (byte&0x80)>>7;
			if ( 1 ) {
				o = bit * 4;
				dst[0] = map[o++];
				dst[1] = map[o++];
				dst[2] = map[o++];
			}
			byte <<= 1;
			dst += 3;
		}
		src += srcskip;
		dst += dstskip;
	}
}
static void BlitBto4(SDL_BlitInfo *info)
{
	int width, height;
	Uint8 *src;
	Uint32 *map, *dst;
	int srcskip, dstskip;
	int c;

	/* Set up some basic variables */
	width = info->d_width;
	height = info->d_height;
	src = info->s_pixels;
	srcskip = info->s_skip;
	dst = (Uint32 *)info->d_pixels;
	dstskip = info->d_skip/4;
	map = (Uint32 *)info->table;
	srcskip += width-(width+7)/8;

	while ( height-- ) {
	        Uint8 byte = 0, bit;
	    	for ( c=0; c<width; ++c ) {
			if ( (c&7) == 0 ) {
				byte = *src++;
			}
			bit = (byte&0x80)>>7;
			if ( 1 ) {
				*dst = map[bit];
			}
			byte <<= 1;
			dst++;
		}
		src += srcskip;
		dst += dstskip;
	}
}

static void BlitBto1Key(SDL_BlitInfo *info)
{
        int width = info->d_width;
	int height = info->d_height;
	Uint8 *src = info->s_pixels;
	Uint8 *dst = info->d_pixels;
	int srcskip = info->s_skip;
	int dstskip = info->d_skip;
	Uint32 ckey = info->src->colorkey;
	Uint8 *palmap = info->table;
	int c;

	/* Set up some basic variables */
	srcskip += width-(width+7)/8;

	if ( palmap ) {
		while ( height-- ) {
		        Uint8  byte = 0, bit;
	    		for ( c=0; c<width; ++c ) {
				if ( (c&7) == 0 ) {
					byte = *src++;
				}
				bit = (byte&0x80)>>7;
				if ( bit != ckey ) {
				  *dst = palmap[bit];
				}
				dst++;
				byte <<= 1;
			}
			src += srcskip;
			dst += dstskip;
		}
	} else {
		while ( height-- ) {
		        Uint8  byte = 0, bit;
	    		for ( c=0; c<width; ++c ) {
				if ( (c&7) == 0 ) {
					byte = *src++;
				}
				bit = (byte&0x80)>>7;
				if ( bit != ckey ) {
				  *dst = bit;
				}
				dst++;
				byte <<= 1;
			}
			src += srcskip;
			dst += dstskip;
		}
	}
}

static void BlitBto2Key(SDL_BlitInfo *info)
{
        int width = info->d_width;
	int height = info->d_height;
	Uint8 *src = info->s_pixels;
	Uint16 *dstp = (Uint16 *)info->d_pixels;
	int srcskip = info->s_skip;
	int dstskip = info->d_skip;
	Uint32 ckey = info->src->colorkey;
	Uint8 *palmap = info->table;
	int c;

	/* Set up some basic variables */
	srcskip += width-(width+7)/8;
	dstskip /= 2;

	while ( height-- ) {
	        Uint8 byte = 0, bit;
	    	for ( c=0; c<width; ++c ) {
			if ( (c&7) == 0 ) {
				byte = *src++;
			}
			bit = (byte&0x80)>>7;
			if ( bit != ckey ) {
				*dstp=((Uint16 *)palmap)[bit];
			}
			byte <<= 1;
			dstp++;
		}
		src += srcskip;
		dstp += dstskip;
	}
}

static void BlitBto3Key(SDL_BlitInfo *info)
{
        int width = info->d_width;
	int height = info->d_height;
	Uint8 *src = info->s_pixels;
	Uint8 *dst = info->d_pixels;
	int srcskip = info->s_skip;
	int dstskip = info->d_skip;
	Uint32 ckey = info->src->colorkey;
	Uint8 *palmap = info->table;
	int c;

	/* Set up some basic variables */
	srcskip += width-(width+7)/8;

	while ( height-- ) {
	        Uint8  byte = 0, bit;
	    	for ( c=0; c<width; ++c ) {
			if ( (c&7) == 0 ) {
				byte = *src++;
			}
			bit = (byte&0x80)>>7;
			if ( bit != ckey ) {
				memcpy(dst, &palmap[bit*4], 3);
			}
			byte <<= 1;
			dst += 3;
		}
		src += srcskip;
		dst += dstskip;
	}
}

static void BlitBto4Key(SDL_BlitInfo *info)
{
        int width = info->d_width;
	int height = info->d_height;
	Uint8 *src = info->s_pixels;
	Uint32 *dstp = (Uint32 *)info->d_pixels;
	int srcskip = info->s_skip;
	int dstskip = info->d_skip;
	Uint32 ckey = info->src->colorkey;
	Uint8 *palmap = info->table;
	int c;

	/* Set up some basic variables */
	srcskip += width-(width+7)/8;
	dstskip /= 4;

	while ( height-- ) {
	        Uint8 byte = 0, bit;
	    	for ( c=0; c<width; ++c ) {
			if ( (c&7) == 0 ) {
				byte = *src++;
			}
			bit = (byte&0x80)>>7;
			if ( bit != ckey ) {
				*dstp=((Uint32 *)palmap)[bit];
			}
			byte <<= 1;
			dstp++;
		}
		src += srcskip;
		dstp += dstskip;
	}
}

static void BlitBtoNAlpha(SDL_BlitInfo *info)
{
        int width = info->d_width;
	int height = info->d_height;
	Uint8 *src = info->s_pixels;
	Uint8 *dst = info->d_pixels;
	int srcskip = info->s_skip;
	int dstskip = info->d_skip;
	const SDL_Color *srcpal	= info->src->palette->colors;
	SDL_PixelFormat *dstfmt = info->dst;
	int  dstbpp;
	int c;
	const int A = info->src->alpha;

	/* Set up some basic variables */
	dstbpp = dstfmt->BytesPerPixel;
	srcskip += width-(width+7)/8;

	while ( height-- ) {
	        Uint8 byte = 0, bit;
	    	for ( c=0; c<width; ++c ) {
			if ( (c&7) == 0 ) {
				byte = *src++;
			}
			bit = (byte&0x80)>>7;
			if ( 1 ) {
			        Uint32 pixel;
			        unsigned sR, sG, sB;
				unsigned dR, dG, dB;
				sR = srcpal[bit].r;
				sG = srcpal[bit].g;
				sB = srcpal[bit].b;
				DISEMBLE_RGB(dst, dstbpp, dstfmt,
							pixel, dR, dG, dB);
				ALPHA_BLEND(sR, sG, sB, A, dR, dG, dB);
			  	ASSEMBLE_RGB(dst, dstbpp, dstfmt, dR, dG, dB);
			}
			byte <<= 1;
			dst += dstbpp;
		}
		src += srcskip;
		dst += dstskip;
	}
}

static void BlitBtoNAlphaKey(SDL_BlitInfo *info)
{
        int width = info->d_width;
	int height = info->d_height;
	Uint8 *src = info->s_pixels;
	Uint8 *dst = info->d_pixels;
	int srcskip = info->s_skip;
	int dstskip = info->d_skip;
	SDL_PixelFormat *srcfmt = info->src;
	SDL_PixelFormat *dstfmt = info->dst;
	const SDL_Color *srcpal	= srcfmt->palette->colors;
	int dstbpp;
	int c;
	const int A = srcfmt->alpha;
	Uint32 ckey = srcfmt->colorkey;

	/* Set up some basic variables */
	dstbpp = dstfmt->BytesPerPixel;
	srcskip += width-(width+7)/8;

	while ( height-- ) {
	        Uint8  byte = 0, bit;
	    	for ( c=0; c<width; ++c ) {
			if ( (c&7) == 0 ) {
				byte = *src++;
			}
			bit = (byte&0x80)>>7;
			if ( bit != ckey ) {
			        int sR, sG, sB;
				int dR, dG, dB;
				Uint32 pixel;
				sR = srcpal[bit].r;
				sG = srcpal[bit].g;
				sB = srcpal[bit].b;
				DISEMBLE_RGB(dst, dstbpp, dstfmt,
							pixel, dR, dG, dB);
				ALPHA_BLEND(sR, sG, sB, A, dR, dG, dB);
			  	ASSEMBLE_RGB(dst, dstbpp, dstfmt, dR, dG, dB);
			}
			byte <<= 1;
			dst += dstbpp;
		}
		src += srcskip;
		dst += dstskip;
	}
}

static SDL_loblit bitmap_blit[] = {
	NULL, BlitBto1, BlitBto2, BlitBto3, BlitBto4
};

static SDL_loblit colorkey_blit[] = {
    NULL, BlitBto1Key, BlitBto2Key, BlitBto3Key, BlitBto4Key
};

SDL_loblit SDL_CalculateBlit0(SDL_Surface *surface, int blit_index)
{
	int which;

	if ( surface->map->dst->format->BitsPerPixel < 8 ) {
		which = 0;
	} else {
		which = surface->map->dst->format->BytesPerPixel;
	}
	switch(blit_index) {
	case 0:			/* copy */
	    return bitmap_blit[which];

	case 1:			/* colorkey */
	    return colorkey_blit[which];

	case 2:			/* alpha */
	    return which >= 2 ? BlitBtoNAlpha : NULL;

	case 4:			/* alpha + colorkey */
	    return which >= 2 ? BlitBtoNAlphaKey : NULL;
	}
	return NULL;
}