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annotate docs/man3/SDL_SetGamma.3 @ 2328:91e601d9df8b

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re: bug#563. checking in some commented out trace code and a fix so that the in testalpha.c the background only flashes when alpha == 255. The problem that is being fixed is caused by clearing SDL_COPY_RLE_COLORKEY without setting SDL_COPY_RLE_DESIRED in SDL_UnRELSurface.
author Bob Pendleton <bob@pendleton.com>
date Fri, 14 Mar 2008 18:17:49 +0000
parents 546f7c1eb755
children 1238da4a7112
rev   line source
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1 .TH "SDL_SetGamma" "3" "Tue 11 Sep 2001, 23:01" "SDL" "SDL API Reference"
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2 .SH "NAME"
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3 SDL_SetGamma \- Sets the color gamma function for the display
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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 \fBint \fBSDL_SetGamma\fP\fR(\fBfloat redgamma, float greengamma, float bluegamma\fR);
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9 .SH "DESCRIPTION"
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10 .PP
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11 Sets the "gamma function" for the display of each color component\&. Gamma controls the brightness/contrast of colors displayed on the screen\&. A gamma value of 1\&.0 is identity (i\&.e\&., no adjustment is made)\&.
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12 .PP
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13 This function adjusts the gamma based on the "gamma function" parameter, you can directly specify lookup tables for gamma adjustment with \fISDL_SetGammaRamp\fR\&.
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14 .PP
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15 Not all display hardware is able to change gamma\&.
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16 .SH "RETURN VALUE"
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17 .PP
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18 Returns -1 on error (or if gamma adjustment is not supported)\&.
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19 .SH "SEE ALSO"
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20 .PP
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21 \fISDL_GetGammaRamp\fR \fISDL_SetGammaRamp\fR
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22 ...\" created by instant / docbook-to-man, Tue 11 Sep 2001, 23:01