Mercurial > sdl-ios-xcode
view docs/man3/SDL_SetGamma.3 @ 1240:3b8a43c428bb
From Bug #36:
There are a couple of issues with the selection of Altivec alpha-blitting
routines in CalculateAlphaBlit() in src/video/SDL_Blit_A.c.
1) There's no check for the presence of Altivec when checking if the
Blit32to565PixelAlphaAltivec() routine can be selected.
2) Altivec cannot be used in video memory, and there's no check if the
destination surface is a hardware surface. (Alpha-blitting to a hardware
surface with GPU support is a bad idea, but somebody's bound to do it anyway.)
Patch to fix these attached.
| author | Ryan C. Gordon <icculus@icculus.org> |
|---|---|
| date | Sun, 08 Jan 2006 21:18:15 +0000 |
| parents | e5bc29de3f0a |
| children | 546f7c1eb755 |
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.TH "SDL_SetGamma" "3" "Tue 11 Sep 2001, 23:01" "SDL" "SDL API Reference" .SH "NAME" SDL_SetGamma\- Sets the color gamma function for the display .SH "SYNOPSIS" .PP \fB#include "SDL\&.h" .sp \fBint \fBSDL_SetGamma\fP\fR(\fBfloat redgamma, float greengamma, float bluegamma\fR); .SH "DESCRIPTION" .PP 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)\&. .PP This function adjusts the gamma based on the "gamma function" parameter, you can directly specify lookup tables for gamma adjustment with \fISDL_SetGammaRamp\fR\&. .PP Not all display hardware is able to change gamma\&. .SH "RETURN VALUE" .PP Returns -1 on error (or if gamma adjustment is not supported)\&. .SH "SEE ALSO" .PP \fISDL_GetGammaRamp\fR \fISDL_SetGammaRamp\fR ...\" created by instant / docbook-to-man, Tue 11 Sep 2001, 23:01