Fixed bug #15 SDL_blit_A.mmx-speed.patch.txt -- Speed improvements and a bugfix for the current GCC inline mmx asm code: - Changed some ops and removed some resulting useless ones. - Added some instruction parallelism (some gain) The resulting speed on my Xeon improved upto 35% depending on the function (measured in fps). - Fixed a bug where BlitRGBtoRGBSurfaceAlphaMMX() was setting the alpha component on the destination surfaces (to opaque-alpha) even when the surface had none. SDL_blit_A.mmx-msvc.patch.txt -- MSVC mmx intrinsics version of the same GCC asm code. MSVC compiler tries to parallelize the code and to avoid register stalls, but does not always do a very good job. Per-surface blending MSVC functions run quite a bit faster than their pure-asm counterparts (upto 55% faster for 16bit ones), but the per-pixel blending runs somewhat slower than asm. - BlitRGBtoRGBSurfaceAlphaMMX and BlitRGBtoRGBPixelAlphaMMX (and all variants) can now also handle formats other than (A)RGB8888. Formats like RGBA8888 and some quite exotic ones are allowed -- like RAGB8888, or actually anything having channels aligned on 8bit boundary and full 8bit alpha (for per-pixel alpha blending). The performance cost of this change is virtually 0 for per-surface alpha blending (no extra ops inside the loop) and a single non-MMX op inside the loop for per-pixel blending. In testing, the per-pixel alpha blending takes a ~2% performance hit, but it still runs much faster than the current code in CVS. If necessary, a separate function with this functionality can be made. This code requires Processor Pack for VC6.

/* $XFree86: xc/include/extensions/Xinerama.h,v 3.2 2000/03/01 01:04:20 dawes Exp $ */

#ifndef _Xinerama_h
#define _Xinerama_h

#include "SDL_name.h"

typedef struct {
   int   screen_number;
   short x_org;
   short y_org;
   short width;
   short height;
} SDL_NAME(XineramaScreenInfo);

Bool SDL_NAME(XineramaQueryExtension) (
   Display *dpy,
   int     *event_base,
   int     *error_base
);

Status SDL_NAME(XineramaQueryVersion)(
   Display *dpy,
   int     *major,
   int     *minor
);

Bool SDL_NAME(XineramaIsActive)(Display *dpy);


/* 
   Returns the number of heads and a pointer to an array of
   structures describing the position and size of the individual
   heads.  Returns NULL and number = 0 if Xinerama is not active.
  
   Returned array should be freed with XFree().
*/

SDL_NAME(XineramaScreenInfo) * 
SDL_NAME(XineramaQueryScreens)(
   Display *dpy,
   int     *number
);

#endif /* _Xinerama_h */