view src/video/x11/SDL_x11dyn.c @ 1240:3b8a43c428bb

From Bug #36: There are a couple of issues with the selection of Altivec alpha-blitting routines in CalculateAlphaBlit() in src/video/SDL_Blit_A.c. 1) There's no check for the presence of Altivec when checking if the Blit32to565PixelAlphaAltivec() routine can be selected. 2) Altivec cannot be used in video memory, and there's no check if the destination surface is a hardware surface. (Alpha-blitting to a hardware surface with GPU support is a bad idea, but somebody's bound to do it anyway.) Patch to fix these attached.
author Ryan C. Gordon <icculus@icculus.org>
date Sun, 08 Jan 2006 21:18:15 +0000
parents ed252764287a
children fe7d081a4955
line wrap: on
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/*
    SDL - Simple DirectMedia Layer
    Copyright (C) 1997-2004 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
*/

#if 0
#define DEBUG_DYNAMIC_X11 1
#endif

#define __SDL_NO_REDEFINE_X11_HEADER_SYMS 1
#include "SDL_x11dyn.h"

#ifdef DEBUG_DYNAMIC_X11
#include <stdio.h>
#endif

#ifdef X11_DYNAMIC
#include <dlfcn.h>
#include "SDL_name.h"
#include "SDL_loadso.h"
static const char *x11_library = X11_DYNAMIC;
static void *x11_handle = NULL;
static const char *x11ext_library = X11EXT_DYNAMIC;
static void *x11ext_handle = NULL;

static void *X11_GetSym(int required, const char *fnname, int *rc)
{
	void *fn = NULL;
	if (*rc) {  /* haven't already failed on a previous lookup? */
		fn = SDL_LoadFunction(x11_handle, fnname);
		#if DEBUG_DYNAMIC_X11
		if (fn != NULL)
			printf("X11: Found '%s' in libX11 (%p)\n", fnname, fn);
		#endif

		if (fn == NULL) {  /* not found? Check libX11ext ... */
			fn = SDL_LoadFunction(x11ext_handle, fnname);
			#if DEBUG_DYNAMIC_X11
			if (fn != NULL)
				printf("X11: Found '%s' in libXext (%p)\n", fnname, fn);
			else
				printf("X11: Symbol '%s' NOT FOUND!%s\n", fnname
				       required ? "" : " (...but not required!)");
			#endif
		}
		*rc = ((fn != NULL) || (!required));
	}

	return fn;
}
#endif  /* defined X11_DYNAMIC */

/* Define all the function pointers... */
#define SDL_X11_SYM(req,ret,fn,params) ret (*p##fn) params = NULL;
#include "SDL_x11sym.h"
#undef SDL_X11_SYM

static int x11_load_refcount = 0;

void SDL_X11_UnloadSymbols(void)
{
	/* Don't actually unload if more than one module is using the libs... */
	if (x11_load_refcount > 0) {
		if (--x11_load_refcount == 0) {
			/* set all the function pointers to NULL. */
			#define SDL_X11_SYM(req,ret,fn,params) p##fn = NULL;
			#include "SDL_x11sym.h"
			#undef SDL_X11_SYM

			#ifdef X11_DYNAMIC
			if (x11_handle != NULL) {
				SDL_UnloadObject(x11_handle);
				x11_handle = NULL;
			}
			if (x11ext_handle != NULL) {
				SDL_UnloadObject(x11ext_handle);
				x11ext_handle = NULL;
			}
			#endif
		}
	}
}

/* returns non-zero if all needed symbols were loaded. */
int SDL_X11_LoadSymbols(void)
{
	int rc = 1;

    /* deal with multiple modules (dga, x11, etc) needing these symbols... */
	if (x11_load_refcount++ == 0) {
		#ifdef X11_DYNAMIC
			x11_handle = SDL_LoadObject(x11_library);
			x11ext_handle = SDL_LoadObject(x11ext_library);
			rc = ((x11_handle != NULL) && (x11ext_handle != NULL));
			#define SDL_X11_SYM(req,r,fn,arg) p##fn = X11_GetSym(req,#fn, &rc);
			#include "SDL_x11sym.h"
			#undef SDL_X11_SYM

			if (!rc)
				SDL_X11_UnloadSymbols();  /* in case one of these loaded... */

		#else
			#define SDL_X11_SYM(req,r,fn,arg) p##fn = fn;
			#include "SDL_x11sym.h"
			#undef SDL_X11_SYM
		#endif
	}

	return rc;
}

/* end of SDL_x11dyn.c ... */