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.

.TH "SDL_VideoModeOK" "3" "Tue 11 Sep 2001, 23:01" "SDL" "SDL API Reference" 
.SH "NAME"
SDL_VideoModeOK\- Check to see if a particular video mode is supported\&.
.SH "SYNOPSIS"
.PP
\fB#include "SDL\&.h"
.sp
\fBint \fBSDL_VideoModeOK\fP\fR(\fBint width, int height, int bpp, Uint32 flags\fR);
.SH "DESCRIPTION"
.PP
\fBSDL_VideoModeOK\fP returns \fB0\fR if the requested mode is not supported under any bit depth, or returns the bits-per-pixel of the closest available mode with the given width, height and requested \fIsurface\fR flags (see \fI\fBSDL_SetVideoMode\fP\fR)\&.
.PP
The bits-per-pixel value returned is only a suggested mode\&. You can usually request and bpp you want when \fIsetting\fR the video mode and SDL will emulate that color depth with a shadow video surface\&.
.PP
The arguments to \fBSDL_VideoModeOK\fP are the same ones you would pass to \fISDL_SetVideoMode\fR
.SH "EXAMPLE"
.PP
.nf
\f(CWSDL_Surface *screen;
Uint32 bpp;
\&.
\&.
\&.
printf("Checking mode 640x480@16bpp\&.
");
bpp=SDL_VideoModeOK(640, 480, 16, SDL_HWSURFACE);

if(!bpp){
  printf("Mode not available\&.
");
  exit(-1);
}

printf("SDL Recommends 640x480@%dbpp\&.
", bpp);
screen=SDL_SetVideoMode(640, 480, bpp, SDL_HWSURFACE);
\&.
\&.\fR
.fi
.PP
.SH "SEE ALSO"
.PP
\fI\fBSDL_SetVideoMode\fP\fR, \fI\fBSDL_GetVideoInfo\fP\fR
...\" created by instant / docbook-to-man, Tue 11 Sep 2001, 23:01