view docs/man3/SDL_GetRGBA.3 @ 872:e7be95d758e8

Date: Fri, 05 Mar 2004 16:08:01 +0000 From: Alan Swanson Subject: Re: [SDL] Fatal signal when initiaize with USB joystick on 2.6.2 kern On Fri, 2004-03-05 at 15:09, Sam Lantinga wrote: > > Fred, how does the attached patch work for you? Do all your axes work? > > I think you meant the two lines to be reversed. > I checked a more robust version of this into CVS. Fred, can you see if > it works? You've misread the code. :-/ For coef[0] and coef[1], it is (values[2]+values[1]) / 2 and then add or subtract values[4] to the answer.
author Sam Lantinga <slouken@libsdl.org>
date Sat, 06 Mar 2004 02:58:06 +0000
parents e5bc29de3f0a
children 546f7c1eb755
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.TH "SDL_GetRGBA" "3" "Tue 11 Sep 2001, 23:01" "SDL" "SDL API Reference" 
.SH "NAME"
SDL_GetRGBA\- Get RGBA values from a pixel in the specified pixel format\&.
.SH "SYNOPSIS"
.PP
\fB#include "SDL\&.h"
.sp
\fBvoid \fBSDL_GetRGBA\fP\fR(\fBUint32 pixel, SDL_PixelFormat *fmt, Uint8 *r, Uint8 *g, Uint8 *b, Uint8 *a\fR);
.SH "DESCRIPTION"
.PP
Get RGBA component values from a pixel stored in the specified pixel format\&.
.PP
This function uses the entire 8-bit [0\&.\&.255] range when converting color components from pixel formats with less than 8-bits per RGB component (e\&.g\&., a completely white pixel in 16-bit RGB565 format would return [0xff, 0xff, 0xff] not [0xf8, 0xfc, 0xf8])\&.
.PP
If the surface has no alpha component, the alpha will be returned as 0xff (100% opaque)\&.
.SH "SEE ALSO"
.PP
\fISDL_GetRGB\fR, \fISDL_MapRGB\fR, \fISDL_MapRGBA\fR, \fISDL_PixelFormat\fR
...\" created by instant / docbook-to-man, Tue 11 Sep 2001, 23:01