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annotate docs/man3/SDL_ConvertSurface.3 @ 3880:74e828c64315 SDL-1.2

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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 15:45:37 +0000
parents e5bc29de3f0a
children 546f7c1eb755
rev   line source
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1 .TH "SDL_ConvertSurface" "3" "Tue 11 Sep 2001, 23:01" "SDL" "SDL API Reference"
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2 .SH "NAME"
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3 SDL_ConvertSurface\- Converts a surface to the same format as another surface\&.
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4 .SH "SYNOPSIS"
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5 .PP
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6 \fB#include "SDL/SDL\&.h"
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7 .sp
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8 \fBSDL_Surface *\fBSDL_ConvertSurface\fP\fR(\fBSDL_Surface *src, SDL_PixelFormat *fmt, Uint32 flags\fR);
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9 .SH "DESCRIPTION"
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10 .PP
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11 Creates a new surface of the specified format, and then copies and maps the given surface to it\&. If this function fails, it returns \fBNULL\fP\&.
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12 .PP
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13 The \fBflags\fR parameter is passed to \fI\fBSDL_CreateRGBSurface\fP\fR and has those semantics\&.
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14 .PP
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15 This function is used internally by \fI\fBSDL_DisplayFormat\fP\fR\&.
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16 .PP
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17 This function can only be called after SDL_Init\&.
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18 .SH "RETURN VALUE"
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19 .PP
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20 Returns either a pointer to the new surface, or \fBNULL\fP on error\&.
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21 .SH "SEE ALSO"
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22 .PP
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23 \fI\fBSDL_CreateRGBSurface\fP\fR, \fI\fBSDL_DisplayFormat\fP\fR, \fI\fBSDL_PixelFormat\fR\fR, \fI\fBSDL_Surface\fR\fR
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24 ...\" created by instant / docbook-to-man, Tue 11 Sep 2001, 23:01