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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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<HTML ><HEAD ><TITLE >SDL_MapRGBA</TITLE ><META NAME="GENERATOR" CONTENT="Modular DocBook HTML Stylesheet Version 1.64 "><LINK REL="HOME" TITLE="SDL Library Documentation" HREF="index.html"><LINK REL="UP" TITLE="Video" HREF="video.html"><LINK REL="PREVIOUS" TITLE="SDL_MapRGB" HREF="sdlmaprgb.html"><LINK REL="NEXT" TITLE="SDL_GetRGB" HREF="sdlgetrgb.html"></HEAD ><BODY CLASS="REFENTRY" BGCOLOR="#FFF8DC" TEXT="#000000" LINK="#0000ee" VLINK="#551a8b" ALINK="#ff0000" ><DIV CLASS="NAVHEADER" ><TABLE WIDTH="100%" BORDER="0" CELLPADDING="0" CELLSPACING="0" ><TR ><TH COLSPAN="3" ALIGN="center" >SDL Library Documentation</TH ></TR ><TR ><TD WIDTH="10%" ALIGN="left" VALIGN="bottom" ><A HREF="sdlmaprgb.html" >Prev</A ></TD ><TD WIDTH="80%" ALIGN="center" VALIGN="bottom" ></TD ><TD WIDTH="10%" ALIGN="right" VALIGN="bottom" ><A HREF="sdlgetrgb.html" >Next</A ></TD ></TR ></TABLE ><HR ALIGN="LEFT" WIDTH="100%"></DIV ><H1 ><A NAME="SDLMAPRGBA" >SDL_MapRGBA</A ></H1 ><DIV CLASS="REFNAMEDIV" ><A NAME="AEN1303" ></A ><H2 >Name</H2 >SDL_MapRGBA -- Map a RGBA color value to a pixel format.</DIV ><DIV CLASS="REFSYNOPSISDIV" ><A NAME="AEN1306" ></A ><H2 >Synopsis</H2 ><DIV CLASS="FUNCSYNOPSIS" ><A NAME="AEN1307" ></A ><P ></P ><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 ></P ><P ></P ></DIV ></DIV ><DIV CLASS="REFSECT1" ><A NAME="AEN1313" ></A ><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 ></DIV ><DIV CLASS="REFSECT1" ><A NAME="AEN1318" ></A ><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 ></DIV ><DIV CLASS="REFSECT1" ><A NAME="AEN1323" ></A ><H2 >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 >, <A HREF="sdlpixelformat.html" >SDL_PixelFormat</A ></P ></DIV ><DIV CLASS="NAVFOOTER" ><HR ALIGN="LEFT" WIDTH="100%"><TABLE WIDTH="100%" BORDER="0" CELLPADDING="0" CELLSPACING="0" ><TR ><TD WIDTH="33%" ALIGN="left" VALIGN="top" ><A HREF="sdlmaprgb.html" >Prev</A ></TD ><TD WIDTH="34%" ALIGN="center" VALIGN="top" ><A HREF="index.html" >Home</A ></TD ><TD WIDTH="33%" ALIGN="right" VALIGN="top" ><A HREF="sdlgetrgb.html" >Next</A ></TD ></TR ><TR ><TD WIDTH="33%" ALIGN="left" VALIGN="top" >SDL_MapRGB</TD ><TD WIDTH="34%" ALIGN="center" VALIGN="top" ><A HREF="video.html" >Up</A ></TD ><TD WIDTH="33%" ALIGN="right" VALIGN="top" >SDL_GetRGB</TD ></TR ></TABLE ></DIV ></BODY ></HTML >