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_CD" "3" "Tue 11 Sep 2001, 22:58" "SDL" "SDL API Reference" 
.SH "NAME"
SDL_CD\- CDROM Drive Information
.SH "STRUCTURE DEFINITION"
.PP
.nf
\f(CWtypedef struct{
  int id;
  CDstatus status;
  int numtracks;
  int cur_track;
  int cur_frame;
  SDL_CDtrack track[SDL_MAX_TRACKS+1];
} SDL_CD;\fR
.fi
.PP
.SH "STRUCTURE DATA"
.TP 20
\fBid\fR
Private drive identifier
.TP 20
\fBstatus\fR
Drive \fIstatus\fR
.TP 20
\fBnumtracks\fR
Number of tracks on the CD
.TP 20
\fBcur_track\fR
Current track
.TP 20
\fBcur_frame\fR
Current frame offset within the track
.TP 20
\fBtrack\fR[SDL_MAX_TRACKS+1]
Array of track descriptions\&. (see \fI\fBSDL_CDtrack\fR\fR)
.SH "DESCRIPTION"
.PP
An \fBSDL_CD\fR structure is returned by \fI\fBSDL_CDOpen\fP\fR\&. It represents an opened CDROM device and stores information on the layout of the tracks on the disc\&.
.PP
A frame is the base data unit of a CD\&. \fBCD_FPS\fP frames is equal to 1 second of music\&. SDL provides two macros for converting between time and frames: \fBFRAMES_TO_MSF(f, M,S,F)\fP and \fBMSF_TO_FRAMES\fP\&.
.SH "EXAMPLES"
.PP
.nf
\f(CWint min, sec, frame;
int frame_offset;

FRAMES_TO_MSF(cdrom->cur_frame, &min, &sec, &frame);
printf("Current Position: %d minutes, %d seconds, %d frames
", min, sec, frame);

frame_offset=MSF_TO_FRAMES(min, sec, frame);\fR
.fi
.PP
.SH "SEE ALSO"
.PP
\fI\fBSDL_CDOpen\fP\fR, \fI\fBSDL_CDtrack\fR\fR
...\" created by instant / docbook-to-man, Tue 11 Sep 2001, 22:58