view docs/html/sdlpalette.html @ 1240:3b8a43c428bb

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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><H1
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>SDL_Palette</H1
><DIV
CLASS="REFNAMEDIV"
><A
NAME="AEN3129"
></A
><H2
>Name</H2
>SDL_Palette&nbsp;--&nbsp;Color palette for 8-bit pixel formats</DIV
><DIV
CLASS="REFSECT1"
><A
NAME="AEN3132"
></A
><H2
>Structure Definition</H2
><PRE
CLASS="PROGRAMLISTING"
>typedef struct{
  int ncolors;
  SDL_Color *colors;
} SDL_Palette;</PRE
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><H2
>Structure Data</H2
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><TT
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><I
>ncolors</I
></TT
></TD
><TD
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VALIGN="TOP"
>Number of colors used in this palette</TD
></TR
><TR
><TD
ALIGN="LEFT"
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><TT
CLASS="STRUCTFIELD"
><I
>colors</I
></TT
></TD
><TD
ALIGN="LEFT"
VALIGN="TOP"
>Pointer to <A
HREF="sdlcolor.html"
><SPAN
CLASS="STRUCTNAME"
>SDL_Color</SPAN
></A
> structures that make up the palette.</TD
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><H2
>Description</H2
><P
>Each pixel in an 8-bit surface is an index into the <TT
CLASS="STRUCTFIELD"
><I
>colors</I
></TT
> field of the <SPAN
CLASS="STRUCTNAME"
>SDL_Palette</SPAN
> structure store in <A
HREF="sdlpixelformat.html"
><SPAN
CLASS="STRUCTNAME"
>SDL_PixelFormat</SPAN
></A
>. A <SPAN
CLASS="STRUCTNAME"
>SDL_Palette</SPAN
> should never need to be created manually. It is automatically created when SDL allocates a <SPAN
CLASS="STRUCTNAME"
>SDL_PixelFormat</SPAN
> for a surface. The colors values of a <A
HREF="sdlsurface.html"
><SPAN
CLASS="STRUCTNAME"
>SDL_Surface</SPAN
></A
>s palette can be set with the <A
HREF="sdlsetcolors.html"
><TT
CLASS="FUNCTION"
>SDL_SetColors</TT
></A
>.</P
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><H2
>See Also</H2
><P
><A
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><SPAN
CLASS="STRUCTNAME"
>SDL_Color</SPAN
></A
>,
<A
HREF="sdlsurface.html"
><SPAN
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>SDL_Surface</SPAN
></A
>,
<A
HREF="sdlsetcolors.html"
><TT
CLASS="FUNCTION"
>SDL_SetColors</TT
></A
>
<A
HREF="sdlsetpalette.html"
><TT
CLASS="FUNCTION"
>SDL_SetPalette</TT
></A
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