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view docs/html/sdlmaprgb.html @ 914:bbf8dcc8aed6
Date: Wed, 23 Jun 2004 17:05:33 -0400
From: Chris Nelson
Subject: [SDL] [Patch] WiseGroup MP-8800 / MP-8866 (PS2 Joystick)
In the current cvs version, SDL doesn't handle these Playstation2
controller => USB adapters correctly, in linux.
It will always assume that the maximum number of joysticks (2 in the
case of the MP-8866, 4 in the case of the 8800) are plugged in. This is
bad not only because it allows SDL to exaggerate the number of logical
joysticks, but primarily because the joystick axes are mapped
incorrectly, all over the place, such that the devices are effectively
unusable unless you have the maximum number of joysticks plugged in.
My changes to src/joystick/linux/SDL_sysjoystick.c build on another's
previous work (which was a special case for this very joystick,
actually), and fix both of these problems, as well as making the current
code a little more general, to allow for others to more easily drop in
code for quirky joysticks such as these.
I've tested this code under 2.6.7 as well as 2.4.24... Both work as
advertised (provided you load the JOYDEV linux code as a module,
otherwise they won't work at all, new code or old, but that's another
issue entirely).
Though this sounds horribly formal, you have my permission to distribute
all of my work on this issue under the LGPL. So there.
author | Sam Lantinga <slouken@libsdl.org> |
---|---|
date | Sun, 25 Jul 2004 18:31:50 +0000 |
parents | 355632dca928 |
children |
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<HTML ><HEAD ><TITLE >SDL_MapRGB</TITLE ><META NAME="GENERATOR" CONTENT="Modular DocBook HTML Stylesheet Version 1.76b+ "><LINK REL="HOME" TITLE="SDL Library Documentation" HREF="index.html"><LINK REL="UP" TITLE="Video" HREF="video.html"><LINK REL="PREVIOUS" TITLE="SDL_SetGammaRamp" HREF="sdlsetgammaramp.html"><LINK REL="NEXT" TITLE="SDL_MapRGBA" HREF="sdlmaprgba.html"></HEAD ><BODY CLASS="REFENTRY" BGCOLOR="#FFF8DC" TEXT="#000000" LINK="#0000ee" VLINK="#551a8b" ALINK="#ff0000" ><DIV CLASS="NAVHEADER" ><TABLE SUMMARY="Header navigation 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="sdlsetgammaramp.html" ACCESSKEY="P" >Prev</A ></TD ><TD WIDTH="80%" ALIGN="center" VALIGN="bottom" ></TD ><TD WIDTH="10%" ALIGN="right" VALIGN="bottom" ><A HREF="sdlmaprgba.html" ACCESSKEY="N" >Next</A ></TD ></TR ></TABLE ><HR ALIGN="LEFT" WIDTH="100%"></DIV ><H1 ><A NAME="SDLMAPRGB" ></A >SDL_MapRGB</H1 ><DIV CLASS="REFNAMEDIV" ><A NAME="AEN1652" ></A ><H2 >Name</H2 >SDL_MapRGB -- Map a RGB color value to a pixel format.</DIV ><DIV CLASS="REFSYNOPSISDIV" ><A NAME="AEN1655" ></A ><H2 >Synopsis</H2 ><DIV CLASS="FUNCSYNOPSIS" ><A NAME="AEN1656" ></A ><P ></P ><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 ></P ><P ></P ></DIV ></DIV ><DIV CLASS="REFSECT1" ><A NAME="AEN1662" ></A ><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 ><DIV CLASS="REFSECT1" ><A NAME="AEN1667" ></A ><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 ></DIV ><DIV CLASS="REFSECT1" ><A NAME="AEN1672" ></A ><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 >, <A HREF="sdlpixelformat.html" ><SPAN CLASS="STRUCTNAME" >SDL_PixelFormat</SPAN ></A ></P ></DIV ><DIV CLASS="NAVFOOTER" ><HR ALIGN="LEFT" WIDTH="100%"><TABLE SUMMARY="Footer navigation table" WIDTH="100%" BORDER="0" CELLPADDING="0" CELLSPACING="0" ><TR ><TD WIDTH="33%" ALIGN="left" VALIGN="top" ><A HREF="sdlsetgammaramp.html" ACCESSKEY="P" >Prev</A ></TD ><TD WIDTH="34%" ALIGN="center" VALIGN="top" ><A HREF="index.html" ACCESSKEY="H" >Home</A ></TD ><TD WIDTH="33%" ALIGN="right" VALIGN="top" ><A HREF="sdlmaprgba.html" ACCESSKEY="N" >Next</A ></TD ></TR ><TR ><TD WIDTH="33%" ALIGN="left" VALIGN="top" >SDL_SetGammaRamp</TD ><TD WIDTH="34%" ALIGN="center" VALIGN="top" ><A HREF="video.html" ACCESSKEY="U" >Up</A ></TD ><TD WIDTH="33%" ALIGN="right" VALIGN="top" >SDL_MapRGBA</TD ></TR ></TABLE ></DIV ></BODY ></HTML >