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annotate docs/man3/SDL_UpdateRects.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
parents e5bc29de3f0a
children 546f7c1eb755
rev   line source
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1 .TH "SDL_UpdateRects" "3" "Tue 11 Sep 2001, 23:01" "SDL" "SDL API Reference"
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2 .SH "NAME"
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3 SDL_UpdateRects\- Makes sure the given list of rectangles is updated on the given screen\&.
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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_UpdateRects\fP\fR(\fBSDL_Surface *screen, int numrects, SDL_Rect *rects\fR);
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9 .SH "DESCRIPTION"
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10 .PP
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11 Makes sure the given list of rectangles is updated on the given screen\&. The rectangles must all be confined within the screen boundaries (no clipping is done)\&.
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12 .PP
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13 This function should not be called while \fBscreen\fR is \fIlocked\fR\&.
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14 .PP
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15 .RS
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16 \fBNote:
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17 .PP
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18 It is adviced to call this function only once per frame, since each call has some processing overhead\&. This is no restriction since you can pass any number of rectangles each time\&.
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19 .PP
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20 The rectangles are not automatically merged or checked for overlap\&. In general, the programmer can use his knowledge about his particular rectangles to merge them in an efficient way, to avoid overdraw\&.
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21 .RE
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22 .SH "SEE ALSO"
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23 .PP
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24 \fI\fBSDL_UpdateRect\fP\fR, \fI\fBSDL_Rect\fR\fR, \fI\fBSDL_Surface\fR\fR, \fI\fBSDL_LockSurface\fP\fR
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25 ...\" created by instant / docbook-to-man, Tue 11 Sep 2001, 23:01