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_ConvertSurface" "3" "Tue 11 Sep 2001, 23:01" "SDL" "SDL API Reference" 
.SH "NAME"
SDL_ConvertSurface\- Converts a surface to the same format as another surface\&.
.SH "SYNOPSIS"
.PP
\fB#include "SDL/SDL\&.h"
.sp
\fBSDL_Surface *\fBSDL_ConvertSurface\fP\fR(\fBSDL_Surface *src, SDL_PixelFormat *fmt, Uint32 flags\fR);
.SH "DESCRIPTION"
.PP
Creates a new surface of the specified format, and then copies and maps the given surface to it\&. If this function fails, it returns \fBNULL\fP\&.
.PP
The \fBflags\fR parameter is passed to \fI\fBSDL_CreateRGBSurface\fP\fR and has those semantics\&.
.PP
This function is used internally by \fI\fBSDL_DisplayFormat\fP\fR\&.
.PP
This function can only be called after SDL_Init\&.
.SH "RETURN VALUE"
.PP
Returns either a pointer to the new surface, or \fBNULL\fP on error\&.
.SH "SEE ALSO"
.PP
\fI\fBSDL_CreateRGBSurface\fP\fR, \fI\fBSDL_DisplayFormat\fP\fR, \fI\fBSDL_PixelFormat\fR\fR, \fI\fBSDL_Surface\fR\fR
...\" created by instant / docbook-to-man, Tue 11 Sep 2001, 23:01