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From Bug #36: There are a couple of issues with the selection of Altivec alpha-blitting routines in CalculateAlphaBlit() in src/video/SDL_Blit_A.c. 1) There's no check for the presence of Altivec when checking if the Blit32to565PixelAlphaAltivec() routine can be selected. 2) Altivec cannot be used in video memory, and there's no check if the destination surface is a hardware surface. (Alpha-blitting to a hardware surface with GPU support is a bad idea, but somebody's bound to do it anyway.) Patch to fix these attached.
author Ryan C. Gordon <icculus@icculus.org>
date Sun, 08 Jan 2006 21:18:15 +0000
parents 355632dca928
children
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<HTML
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>SDL_GetRGB</TITLE
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><H1
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>SDL_GetRGB</H1
><DIV
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><A
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><H2
>Name</H2
>SDL_GetRGB&nbsp;--&nbsp;Get RGB values from a pixel in the specified pixel format.</DIV
><DIV
CLASS="REFSYNOPSISDIV"
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><H2
>Synopsis</H2
><DIV
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><P
></P
><PRE
CLASS="FUNCSYNOPSISINFO"
>#include "SDL.h"</PRE
><P
><CODE
><CODE
CLASS="FUNCDEF"
>void <B
CLASS="FSFUNC"
>SDL_GetRGB</B
></CODE
>(Uint32 pixel, SDL_PixelFormat *fmt, Uint8 *r, Uint8 *g, Uint8 *b);</CODE
></P
><P
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></DIV
></DIV
><DIV
CLASS="REFSECT1"
><A
NAME="AEN1728"
></A
><H2
>Description</H2
><P
>Get RGB component values from a pixel stored in the specified pixel format.</P
><P
>This function uses the entire 8-bit [0..255] range when converting color
components from pixel formats with less than 8-bits per RGB component
(e.g., a completely white pixel in 16-bit RGB565 format would return
[0xff, 0xff, 0xff] not [0xf8, 0xfc, 0xf8]).</P
></DIV
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><H2
>See Also</H2
><P
><A
HREF="sdlgetrgba.html"
><TT
CLASS="FUNCTION"
>SDL_GetRGBA</TT
></A
>,
<A
HREF="sdlmaprgb.html"
><TT
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>SDL_MapRGB</TT
></A
>,
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><TT
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>SDL_MapRGBA</TT
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>SDL_PixelFormat</SPAN
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