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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_ShowCursor</TITLE
><META
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><H1
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>SDL_ShowCursor</H1
><DIV
CLASS="REFNAMEDIV"
><A
NAME="AEN2615"
></A
><H2
>Name</H2
>SDL_ShowCursor&nbsp;--&nbsp;Toggle whether or not the cursor is shown on the screen.</DIV
><DIV
CLASS="REFSYNOPSISDIV"
><A
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></A
><H2
>Synopsis</H2
><DIV
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><A
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></A
><P
></P
><PRE
CLASS="FUNCSYNOPSISINFO"
>#include "SDL.h"</PRE
><P
><CODE
><CODE
CLASS="FUNCDEF"
>int <B
CLASS="FSFUNC"
>SDL_ShowCursor</B
></CODE
>(int toggle);</CODE
></P
><P
></P
></DIV
></DIV
><DIV
CLASS="REFSECT1"
><A
NAME="AEN2625"
></A
><H2
>Description</H2
><P
>Toggle whether or not the cursor is shown on the screen. Passing <TT
CLASS="LITERAL"
>SDL_ENABLE</TT
> displays the cursor and passing <TT
CLASS="LITERAL"
>SDL_DISABLE</TT
> hides it. The current state of the mouse cursor can be queried by passing <TT
CLASS="LITERAL"
>SDL_QUERY</TT
>, either <TT
CLASS="LITERAL"
>SDL_DISABLE</TT
> or <TT
CLASS="LITERAL"
>SDL_ENABLE</TT
> will be returned.</P
><P
>The cursor starts off displayed, but can be turned off.</P
></DIV
><DIV
CLASS="REFSECT1"
><A
NAME="AEN2634"
></A
><H2
>Return Value</H2
><P
>Returns the current state of the cursor.</P
></DIV
><DIV
CLASS="REFSECT1"
><A
NAME="AEN2637"
></A
><H2
>See Also</H2
><P
><A
HREF="sdlcreatecursor.html"
><TT
CLASS="FUNCTION"
>SDL_CreateCursor</TT
></A
>,
<A
HREF="sdlsetcursor.html"
><TT
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>SDL_SetCursor</TT
></A
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