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annotate docs/man3/SDL_GetRGBA.3 @ 2042:3908e1f808e1

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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 15:56:36 +0000
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children 546f7c1eb755
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1 .TH "SDL_GetRGBA" "3" "Tue 11 Sep 2001, 23:01" "SDL" "SDL API Reference"
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2 .SH "NAME"
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3 SDL_GetRGBA\- Get RGBA values from a pixel in the specified pixel format\&.
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4 .SH "SYNOPSIS"
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5 .PP
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6 \fB#include "SDL\&.h"
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7 .sp
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8 \fBvoid \fBSDL_GetRGBA\fP\fR(\fBUint32 pixel, SDL_PixelFormat *fmt, Uint8 *r, Uint8 *g, Uint8 *b, Uint8 *a\fR);
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9 .SH "DESCRIPTION"
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10 .PP
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11 Get RGBA component values from a pixel stored in the specified pixel format\&.
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12 .PP
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13 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])\&.
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14 .PP
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15 If the surface has no alpha component, the alpha will be returned as 0xff (100% opaque)\&.
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16 .SH "SEE ALSO"
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17 .PP
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18 \fISDL_GetRGB\fR, \fISDL_MapRGB\fR, \fISDL_MapRGBA\fR, \fISDL_PixelFormat\fR
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19 ...\" created by instant / docbook-to-man, Tue 11 Sep 2001, 23:01