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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.
author Sam Lantinga <slouken@libsdl.org>
date Wed, 15 Mar 2006 15:39:29 +0000
parents 355632dca928
children
line wrap: on
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<HTML
><HEAD
><TITLE
>SDL_CDPlayTracks</TITLE
><META
NAME="GENERATOR"
CONTENT="Modular DocBook HTML Stylesheet Version 1.76b+
"><LINK
REL="HOME"
TITLE="SDL Library Documentation"
HREF="index.html"><LINK
REL="UP"
TITLE="CD-ROM"
HREF="cdrom.html"><LINK
REL="PREVIOUS"
TITLE="SDL_CDPlay"
HREF="sdlcdplay.html"><LINK
REL="NEXT"
TITLE="SDL_CDPause"
HREF="sdlcdpause.html"></HEAD
><BODY
CLASS="REFENTRY"
BGCOLOR="#FFF8DC"
TEXT="#000000"
LINK="#0000ee"
VLINK="#551a8b"
ALINK="#ff0000"
><DIV
CLASS="NAVHEADER"
><TABLE
SUMMARY="Header navigation table"
WIDTH="100%"
BORDER="0"
CELLPADDING="0"
CELLSPACING="0"
><TR
><TH
COLSPAN="3"
ALIGN="center"
>SDL Library Documentation</TH
></TR
><TR
><TD
WIDTH="10%"
ALIGN="left"
VALIGN="bottom"
><A
HREF="sdlcdplay.html"
ACCESSKEY="P"
>Prev</A
></TD
><TD
WIDTH="80%"
ALIGN="center"
VALIGN="bottom"
></TD
><TD
WIDTH="10%"
ALIGN="right"
VALIGN="bottom"
><A
HREF="sdlcdpause.html"
ACCESSKEY="N"
>Next</A
></TD
></TR
></TABLE
><HR
ALIGN="LEFT"
WIDTH="100%"></DIV
><H1
><A
NAME="SDLCDPLAYTRACKS"
></A
>SDL_CDPlayTracks</H1
><DIV
CLASS="REFNAMEDIV"
><A
NAME="AEN7375"
></A
><H2
>Name</H2
>SDL_CDPlayTracks&nbsp;--&nbsp;Play the given CD track(s)</DIV
><DIV
CLASS="REFSYNOPSISDIV"
><A
NAME="AEN7378"
></A
><H2
>Synopsis</H2
><DIV
CLASS="FUNCSYNOPSIS"
><A
NAME="AEN7379"
></A
><P
></P
><PRE
CLASS="FUNCSYNOPSISINFO"
>#include "SDL.h"</PRE
><P
><CODE
><CODE
CLASS="FUNCDEF"
>int <B
CLASS="FSFUNC"
>SDL_CDPlayTracks</B
></CODE
>(SDL_CD *cdrom, int start_track, int start_frame, int ntracks, int nframes));</CODE
></P
><P
></P
></DIV
></DIV
><DIV
CLASS="REFSECT1"
><A
NAME="AEN7385"
></A
><H2
>Description</H2
><P
><TT
CLASS="FUNCTION"
>SDL_CDPlayTracks</TT
> plays the given CD starting at track
<TT
CLASS="PARAMETER"
><I
>start_track</I
></TT
>, for <TT
CLASS="PARAMETER"
><I
>ntracks</I
></TT
> tracks.  </P
><P
><TT
CLASS="PARAMETER"
><I
>start_frame</I
></TT
> is the frame offset, from the beginning of the <TT
CLASS="PARAMETER"
><I
>start_track</I
></TT
>, at which to start. <TT
CLASS="PARAMETER"
><I
>nframes</I
></TT
> is the frame offset, from the beginning of the last track (<TT
CLASS="PARAMETER"
><I
>start_track</I
></TT
>+<TT
CLASS="PARAMETER"
><I
>ntracks</I
></TT
>), at which to end playing.</P
><P
><TT
CLASS="FUNCTION"
>SDL_CDPlayTracks</TT
> should only be called after calling 
<A
HREF="sdlcdstatus.html"
><TT
CLASS="FUNCTION"
>SDL_CDStatus</TT
></A
> 
to get track information about the CD.</P
><DIV
CLASS="NOTE"
><BLOCKQUOTE
CLASS="NOTE"
><P
><B
>Note: </B
>Data tracks are ignored.</P
></BLOCKQUOTE
></DIV
></DIV
><DIV
CLASS="REFSECT1"
><A
NAME="AEN7403"
></A
><H2
>Return Value</H2
><P
>Returns <SPAN
CLASS="RETURNVALUE"
>0</SPAN
>, or <SPAN
CLASS="RETURNVALUE"
>-1</SPAN
> 
if there was an error.</P
></DIV
><DIV
CLASS="REFSECT1"
><A
NAME="AEN7408"
></A
><H2
>Examples</H2
><P
><PRE
CLASS="PROGRAMLISTING"
>/* assuming cdrom is a previously opened device */
/* Play the entire CD */
if(CD_INDRIVE(SDL_CDStatus(cdrom)))
  SDL_CDPlayTracks(cdrom, 0, 0, 0, 0);

/* Play the first track */
if(CD_INDRIVE(SDL_CDStatus(cdrom)))
  SDL_CDPlayTracks(cdrom, 0, 0, 1, 0);

/* Play first 15 seconds of the 2nd track */
if(CD_INDRIVE(SDL_CDStatus(cdrom)))
  SDL_CDPlayTracks(cdrom, 1, 0, 0, CD_FPS*15);</PRE
>
&#13;</P
></DIV
><DIV
CLASS="REFSECT1"
><A
NAME="AEN7412"
></A
><H2
>See Also</H2
><P
><A
HREF="sdlcdplay.html"
><TT
CLASS="FUNCTION"
>SDL_CDPlay</TT
></A
>,
<A
HREF="sdlcdstatus.html"
><TT
CLASS="FUNCTION"
>SDL_CDStatus</TT
></A
>,
<A
HREF="sdlcd.html"
><TT
CLASS="FUNCTION"
>SDL_CD</TT
></A
></P
></DIV
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WIDTH="100%"><TABLE
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WIDTH="33%"
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><A
HREF="sdlcdplay.html"
ACCESSKEY="P"
>Prev</A
></TD
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WIDTH="34%"
ALIGN="center"
VALIGN="top"
><A
HREF="index.html"
ACCESSKEY="H"
>Home</A
></TD
><TD
WIDTH="33%"
ALIGN="right"
VALIGN="top"
><A
HREF="sdlcdpause.html"
ACCESSKEY="N"
>Next</A
></TD
></TR
><TR
><TD
WIDTH="33%"
ALIGN="left"
VALIGN="top"
>SDL_CDPlay</TD
><TD
WIDTH="34%"
ALIGN="center"
VALIGN="top"
><A
HREF="cdrom.html"
ACCESSKEY="U"
>Up</A
></TD
><TD
WIDTH="33%"
ALIGN="right"
VALIGN="top"
>SDL_CDPause</TD
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>