view src/video/x11/SDL_x11dyn.c @ 1555:780fd5b61df1

Fixed bug #89 Date: Sun, 23 Oct 2005 16:39:03 +0200 From: "A. Schmid" <sahib@phreaker.net> Subject: [SDL] no software surfaces with svgalib driver? Hi, I noticed that the SDL (1.2.9) svgalib driver only makes use of linear addressable (framebuffer) video modes. On older systems (like one of mine), linear addressable modes are often not available. Especially for cards with VESA VBE < 2.0 the svgalib vesa driver is unusable, since VESA only supports framebuffering for VBE 2.0 and later. The changes necessary to add support for software surfaces seem to be relatively small. I only had to hack src/video/svga/SDL_svgavideo.c (see attached patch). The code worked fine for me, but it is no more than a proof of concept and should be reviewed (probably has a memory leak when switching modes). It also uses the vgagl library (included in the svgalib package) and needs to be linked against it. -Alex
author Sam Lantinga <slouken@libsdl.org>
date Sun, 19 Mar 2006 12:05:16 +0000
parents d910939febfa
children 3ba88cb7eb1b
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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
*/
#include "SDL_config.h"

#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 SDL_VIDEO_DRIVER_X11_DYNAMIC
#include <dlfcn.h>
#include "SDL_name.h"
#include "SDL_loadso.h"
static const char *x11_library = SDL_VIDEO_DRIVER_X11_DYNAMIC;
static void *x11_handle = NULL;
static const char *x11ext_library = SDL_VIDEO_DRIVER_X11_DYNAMIC_XEXT;
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  /* SDL_VIDEO_DRIVER_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 SDL_VIDEO_DRIVER_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 SDL_VIDEO_DRIVER_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 ... */