view src/video/bwindow/SDL_lowvideo.h @ 1544:ab1e4c41ab71

Fixed bug #33 Mike Frysinger wrote: > with libsdl-1.2.9, some games (like bomberclone) started > segfaulting in Gentoo [...snip...] > the last change in the last hunk: [...snip...] > if i change the statement to read: > (table[which].blit_features & GetBlitFeatures()) == GetBlitFeatures() > bomberclone no longer segfaults on my box Alex Volkov wrote: > The test "(table[which].blit_features & GetBlitFeatures()) == > table[which].blit_features)" is correct, and the previous > "(table[which].cpu_mmx == SDL_HasMMX())" was actually broken. I think there is potentially a slightly different cause of the above problem. During the introduction of the Altivec code, the blit_table struct field 'alpha' got changed from a straightforward enum to a bitmask, which makes perfect sense by itself. However, now the table driven blitter selection code in SDL_CalculateBlitN() can choose the wrong blitters when searching for a NO_ALPHA blitter because of the following code: int a_need = 0; ... (a_need & table[which].alpha) == a_need && When searching through the normal_blit_2[] table, a SET_ALPHA blitter (like Blit_RGB565_ARGB8888) can now be selected instead of a NO_ALPHA one, causing alpha channel bits to appear in a non-alpha destination surface. I suppose this could theoretically be an indirect cause of the segfault mentioned above. I *think* this can be fixed by changing to int a_need = NO_ALPHA;
author Sam Lantinga <slouken@libsdl.org>
date Wed, 15 Mar 2006 15:47:49 +0000
parents d910939febfa
children 782fd950bd46 a1b03ba2fcd0
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/*
    SDL - Simple DirectMedia Layer
    Copyright (C) 1997-2006 Sam Lantinga

    This library is free software; you can redistribute it and/or
    modify it under the terms of the GNU Lesser General Public
    License as published by the Free Software Foundation; either
    version 2.1 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
    Lesser General Public License for more details.

    You should have received a copy of the GNU Lesser General Public
    License along with this library; if not, write to the Free Software
    Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA

    Sam Lantinga
    slouken@libsdl.org
*/
#include "SDL_config.h"

#ifndef _SDL_lowvideo_h
#define _SDL_lowvideo_h

#include "SDL_BWin.h"
#include "SDL_mouse.h"
#include "../SDL_sysvideo.h"

/* Hidden "this" pointer for the video functions */
#define _THIS	SDL_VideoDevice *_this

/* Private display data */
struct SDL_PrivateVideoData {
	/* The main window */
	SDL_BWin *SDL_Win;

	/* The fullscreen mode list */
	display_mode saved_mode;
#define NUM_MODELISTS	4		/* 8, 16, 24, and 32 bits-per-pixel */
	int SDL_nummodes[NUM_MODELISTS];
	SDL_Rect **SDL_modelist[NUM_MODELISTS];

	/* A completely clear cursor */
	WMcursor *BlankCursor;

	SDL_Overlay *overlay;
};
/* Old variable names */
#define SDL_Win		(_this->hidden->SDL_Win)
#define saved_mode	(_this->hidden->saved_mode)
#define SDL_nummodes	(_this->hidden->SDL_nummodes)
#define SDL_modelist	(_this->hidden->SDL_modelist)
#define SDL_BlankCursor	(_this->hidden->BlankCursor)
#define current_overlay (_this->hidden->overlay)

#endif /* _SDL_lowvideo_h */