view docs/html/sdlmaprgba.html @ 641:df178851293b

Date: 28 Jun 2003 22:42:52 +0100 From: Alan Swanson Subject: Re: [SDL] New XFree 4.3 Video Mode Patch I have a wee amendment that moves the qsort in set_best_resolution to only occur after failing to find an exact match only. This would make absolutely sure we get a user set mode. While I've never had any problems for my normal resolutions (1280x1024, 1024x768, 800x600 & 640,480) while closely examining the output from qsort I've noticed it doesn't seem to sort the modes fully. These is one definite wrong at 1152x768 and a few that just look wrong to me. From a program (attached) I made to examine this more easily. X has sorted its mode list using the same method as ours (plus frequency), and our user modes get inserted without any other movement. On the patch I've made I've also changed cmpmodes to sort on vertical resolution and then horizontal. Ie vertical is now most significant bit.
author Sam Lantinga <slouken@libsdl.org>
date Sat, 28 Jun 2003 21:52:26 +0000
parents e5bc29de3f0a
children 355632dca928
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>SDL_MapRGBA</A
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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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>Synopsis</H2
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><PRE
CLASS="FUNCSYNOPSISINFO"
>#include "SDL.h"</PRE
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><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
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>If the format has a palette (8-bit) the index of the closest matching
color in the palette will be returned.</P
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>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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><H2
>Return Value</H2
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>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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><A
HREF="sdlgetrgb.html"
>SDL_GetRGB</A
>,
<A
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>SDL_GetRGBA</A
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>SDL_PixelFormat</A
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