view docs/man3/SDL_MapRGBA.3 @ 3880:74e828c64315 SDL-1.2

Fixed bug #292 I might be on crack here. It looks like SDL_ConvertMono() in src/audio/SDL_audiocvt.c adds the left and right channels of a stereo stream together, and clamps the new mono channel if it would overflow. Shouldn't it be dividing by 2 to average the two sample points instead of clamping? Otherwise the mono sample point's volume doubles in the conversion. This would also make the conversion faster, as it replaces two branches per sample frame with a bitwise shift. --ryan.
author Sam Lantinga <slouken@libsdl.org>
date Sun, 24 Sep 2006 15:45:37 +0000
parents e5bc29de3f0a
children 546f7c1eb755
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.TH "SDL_MapRGBA" "3" "Tue 11 Sep 2001, 23:01" "SDL" "SDL API Reference" 
.SH "NAME"
SDL_MapRGBA\- Map a RGBA color value to a pixel format\&.
.SH "SYNOPSIS"
.PP
\fB#include "SDL\&.h"
.sp
\fBUint32 \fBSDL_MapRGBA\fP\fR(\fBSDL_PixelFormat *fmt, Uint8 r, Uint8 g, Uint8 b, Uint8 a\fR);
.SH "DESCRIPTION"
.PP
Maps the RGBA color value to the specified pixel format and returns the pixel value as a 32-bit int\&.
.PP
If the format has a palette (8-bit) the index of the closest matching color in the palette will be returned\&.
.PP
If the specified pixel format has no alpha component the alpha value will be ignored (as it will be in formats with a palette)\&.
.SH "RETURN VALUE"
.PP
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 \fBUint16\fP, and similarly a \fBUint8\fP for an 8-bpp format)\&.
.SH "SEE ALSO"
.PP
\fISDL_GetRGB\fR, \fISDL_GetRGBA\fR, \fISDL_MapRGB\fR, \fISDL_PixelFormat\fR
...\" created by instant / docbook-to-man, Tue 11 Sep 2001, 23:01