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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
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<HTML
><HEAD
><TITLE
>SDL_CDtrack</TITLE
><META
NAME="GENERATOR"
CONTENT="Modular DocBook HTML Stylesheet Version 1.76b+
"><LINK
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><HR
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><H1
><A
NAME="SDLCDTRACK"
></A
>SDL_CDtrack</H1
><DIV
CLASS="REFNAMEDIV"
><A
NAME="AEN7628"
></A
><H2
>Name</H2
>SDL_CDtrack&nbsp;--&nbsp;CD Track Information Structure</DIV
><DIV
CLASS="REFSECT1"
><A
NAME="AEN7631"
></A
><H2
>Structure Definition</H2
><PRE
CLASS="PROGRAMLISTING"
>typedef struct{
  Uint8 id;
  Uint8 type;
  Uint32 length;
  Uint32 offset;
} SDL_CDtrack;</PRE
></DIV
><DIV
CLASS="REFSECT1"
><A
NAME="AEN7634"
></A
><H2
>Structure Data</H2
><DIV
CLASS="INFORMALTABLE"
><A
NAME="AEN7636"
></A
><P
></P
><TABLE
BORDER="0"
CLASS="CALSTABLE"
><TBODY
><TR
><TD
ALIGN="LEFT"
VALIGN="TOP"
><TT
CLASS="STRUCTFIELD"
><I
>id</I
></TT
></TD
><TD
ALIGN="LEFT"
VALIGN="TOP"
>Track number (0-99)</TD
></TR
><TR
><TD
ALIGN="LEFT"
VALIGN="TOP"
><TT
CLASS="STRUCTFIELD"
><I
>type</I
></TT
></TD
><TD
ALIGN="LEFT"
VALIGN="TOP"
><TT
CLASS="LITERAL"
>SDL_AUDIO_TRACK</TT
> or <TT
CLASS="LITERAL"
>SDL_DATA_TRACK</TT
></TD
></TR
><TR
><TD
ALIGN="LEFT"
VALIGN="TOP"
><TT
CLASS="STRUCTFIELD"
><I
>length</I
></TT
></TD
><TD
ALIGN="LEFT"
VALIGN="TOP"
>Length, in frames, of this track</TD
></TR
><TR
><TD
ALIGN="LEFT"
VALIGN="TOP"
><TT
CLASS="STRUCTFIELD"
><I
>offset</I
></TT
></TD
><TD
ALIGN="LEFT"
VALIGN="TOP"
>Frame offset to the beginning of this track</TD
></TR
></TBODY
></TABLE
><P
></P
></DIV
></DIV
><DIV
CLASS="REFSECT1"
><A
NAME="AEN7657"
></A
><H2
>Description</H2
><P
><SPAN
CLASS="STRUCTNAME"
>SDL_CDtrack</SPAN
> stores data on each track on a CD, its fields should be pretty self explainatory. It is a member a the <A
HREF="sdlcd.html"
><SPAN
CLASS="STRUCTNAME"
>SDL_CD</SPAN
></A
> structure.</P
><DIV
CLASS="NOTE"
><BLOCKQUOTE
CLASS="NOTE"
><P
><B
>Note: </B
>Frames can be converted to standard timings. There are <TT
CLASS="LITERAL"
>CD_FPS</TT
> frames per second, so <SPAN
CLASS="STRUCTNAME"
>SDL_CDtrack</SPAN
>.<TT
CLASS="STRUCTFIELD"
><I
>length</I
></TT
>/<TT
CLASS="LITERAL"
>CD_FPS</TT
>=length_in_seconds.</P
></BLOCKQUOTE
></DIV
></DIV
><DIV
CLASS="REFSECT1"
><A
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></A
><H2
>See Also</H2
><P
><A
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><SPAN
CLASS="STRUCTNAME"
>SDL_CD</SPAN
></A
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