view docs/html/sdlmaprgba.html @ 2185:2032348afed1

This code adds support for DirectColor visuals to SDL 1.3. The support uses part of the Xmu library. To ensure that the library is available and to keep people form having to install yet another library I have added the essential parts of Xmu in src/video/extensions/XmuStdCmap and an include file in src/video/extensions. The support makes use of standard X11 mechanisms to create color maps and make sure that an application uses the same color map for each window/visual combination. This should make it possible for gamma support to be implemented based on a single color map per application. Hurm... it looks like "make indent" modified a few extra files. Those are getting committed too.
author Bob Pendleton <bob@pendleton.com>
date Thu, 12 Jul 2007 20:00:50 +0000
parents 355632dca928
children
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>SDL_MapRGBA</H1
><DIV
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><H2
>Name</H2
>SDL_MapRGBA&nbsp;--&nbsp;Map a RGBA color value to a pixel format.</DIV
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CLASS="REFSYNOPSISDIV"
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>Synopsis</H2
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><P
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><PRE
CLASS="FUNCSYNOPSISINFO"
>#include "SDL.h"</PRE
><P
><CODE
><CODE
CLASS="FUNCDEF"
>Uint32 <B
CLASS="FSFUNC"
>SDL_MapRGBA</B
></CODE
>(SDL_PixelFormat *fmt, Uint8 r, Uint8 g, Uint8 b, Uint8 a);</CODE
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><H2
>Description</H2
><P
>Maps the RGBA color value to the specified pixel format and returns the
pixel value as a 32-bit int.</P
><P
>If the format has a palette (8-bit) the index of the closest matching
color in the palette will be returned.</P
><P
>If the specified pixel format has no alpha component the alpha value
will be ignored (as it will be in formats with a palette).</P
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CLASS="REFSECT1"
><A
NAME="AEN1702"
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><H2
>Return Value</H2
><P
>A pixel value best approximating the given RGBA color value for a given
pixel format. If the pixel format bpp (color depth) is less than 32-bpp
then the unused upper bits of the return value can safely be ignored
(e.g., with a 16-bpp format the return value can be assigned to a
<SPAN
CLASS="TYPE"
>Uint16</SPAN
>, and similarly a <SPAN
CLASS="TYPE"
>Uint8</SPAN
> for an 8-bpp
format).</P
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>See Also</H2
><P
><A
HREF="sdlgetrgb.html"
>SDL_GetRGB</A
>,
<A
HREF="sdlgetrgba.html"
>SDL_GetRGBA</A
>,
<A
HREF="sdlmaprgb.html"
>SDL_MapRGB</A
>,
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>SDL_PixelFormat</A
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