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Fixed bug #220 The AltiVec blitters don't compile, since they require __VEC__ to be enabled in order for the compiler to understand "vector" and friends (i.e. do AltiVec) But you don't want to turn AltiVec on globally, since then the code would only run on a G4 (there are already runtime tests, before using the AltiVec variants) The solution here is to enable AltiVec locally, for the actual AltiVec code.
author Sam Lantinga <slouken@libsdl.org>
date Tue, 09 May 2006 15:09:47 +0000
parents 355632dca928
children
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<HTML
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>SDL_SetGamma</TITLE
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><H1
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>SDL_SetGamma</H1
><DIV
CLASS="REFNAMEDIV"
><A
NAME="AEN1569"
></A
><H2
>Name</H2
>SDL_SetGamma&nbsp;--&nbsp;Sets the color gamma function for the display</DIV
><DIV
CLASS="REFSYNOPSISDIV"
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></A
><H2
>Synopsis</H2
><DIV
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><P
></P
><PRE
CLASS="FUNCSYNOPSISINFO"
>#include "SDL.h"</PRE
><P
><CODE
><CODE
CLASS="FUNCDEF"
>int <B
CLASS="FSFUNC"
>SDL_SetGamma</B
></CODE
>(float redgamma, float greengamma, float bluegamma);</CODE
></P
><P
></P
></DIV
></DIV
><DIV
CLASS="REFSECT1"
><A
NAME="AEN1579"
></A
><H2
>Description</H2
><P
>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 <TT
CLASS="CONSTANT"
>1.0</TT
> is identity (i.e., no adjustment
is made).</P
><P
>This function adjusts the gamma based on the "gamma function" parameter,
you can directly specify lookup tables for gamma adjustment with
<A
HREF="sdlsetgammaramp.html"
>SDL_SetGammaRamp</A
>.</P
><P
>Not all display hardware is able to change gamma.</P
></DIV
><DIV
CLASS="REFSECT1"
><A
NAME="AEN1586"
></A
><H2
>Return Value</H2
><P
>Returns -1 on error (or if gamma adjustment is not supported).</P
></DIV
><DIV
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></A
><H2
>See Also</H2
><P
><A
HREF="sdlgetgammaramp.html"
>SDL_GetGammaRamp</A
>
<A
HREF="sdlsetgammaramp.html"
>SDL_SetGammaRamp</A
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