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;

/*
 * Copyright 1993-2001 by Xi Graphics, Inc.
 * All Rights Reserved.
 *
 * Please see the LICENSE file accompanying this distribution for licensing 
 * information. 
 *
 * Please send any bug fixes and modifications to src@xig.com.
 *
 * $XiGId: xme.h,v 1.1.1.1 2001/11/19 19:01:10 jon Exp $
 *
 */


#ifndef _XME_H_INCLUDED 
#define _XME_H_INCLUDED

typedef struct {        
  short		        x;
  short		        y;
  unsigned short	w;
  unsigned short	h;
} XiGMiscViewInfo;

typedef struct {        
  unsigned short        width;
  unsigned short        height;
  int                   refresh;
} XiGMiscResolutionInfo;

extern Bool XiGMiscQueryVersion(Display *dpy, int *major, int *minor);
extern int XiGMiscQueryViews(Display *dpy, int screen, 
			     XiGMiscViewInfo **pviews);
extern int XiGMiscQueryResolutions(Display *dpy, int screen, int view, 
			    int *pactive, 
			    XiGMiscResolutionInfo **presolutions);
extern void XiGMiscChangeResolution(Display *dpy, int screen, int view, 
			     int width, int height, int refresh);
#endif /* _XME_H_INCLUDED */