view docs/html/sdlmaprgb.html @ 885:9f6ad2286011

Date: Wed, 28 Apr 2004 16:52:41 -0400 From: "Damien A" Subject: testdyngl fix The test program you included in the latest version of SDL crashes on startup in Window (XP). The reason for this is that OpenGL functions on Windows use the __stdcall calling convention, not the C convention. Placing APIENTRY infront of the * operator solves this problem.
author Sam Lantinga <slouken@libsdl.org>
date Fri, 30 Apr 2004 18:33:30 +0000
parents 355632dca928
children
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>SDL_MapRGB</TITLE
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><H1
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>SDL_MapRGB</H1
><DIV
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><H2
>Name</H2
>SDL_MapRGB&nbsp;--&nbsp;Map a RGB color value to a pixel format.</DIV
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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_MapRGB</B
></CODE
>(SDL_PixelFormat *fmt, Uint8 r, Uint8 g, Uint8 b);</CODE
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><H2
>Description</H2
><P
>Maps the RGB 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 an alpha component it will be returned
as all 1 bits (fully opaque).</P
></DIV
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CLASS="REFSECT1"
><A
NAME="AEN1667"
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><H2
>Return Value</H2
><P
>A pixel value best approximating the given RGB 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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><H2
>See Also</H2
><P
><A
HREF="sdlgetrgb.html"
><TT
CLASS="FUNCTION"
>SDL_GetRGB</TT
></A
>,
<A
HREF="sdlgetrgba.html"
><TT
CLASS="FUNCTION"
>SDL_GetRGBA</TT
></A
>,
<A
HREF="sdlmaprgba.html"
><TT
CLASS="FUNCTION"
>SDL_MapRGBA</TT
></A
>,
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HREF="sdlpixelformat.html"
><SPAN
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>SDL_PixelFormat</SPAN
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