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view docs/html/sdlsetgamma.html @ 4106:12bb6311fd5d SDL-1.2

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Hans de Goede fixed bug #495 When running boswars: http://www.boswars.org/ on a machine with intel integrathed graphics it crashes when it tries to play the initial theora splashscreen video: X Error of failed request: BadAlloc (insufficient resources for operation) Major opcode of failed request: 140 (XVideo) Minor opcode of failed request: 19 () Serial number of failed request: 25 Current serial number in output stream: 26 boswars: xcb_xlib.c:41: xcb_xlib_lock: Assertion `!c->xlib.lock' failed. Aborted I recognized this problem from a few years back, when I encountered it while working on the Xv blitter for xmame. The problem is that for some reason creation the Xvport and XvImage succeeds, and failure (lack of resources / hw capability?) is only indicated during the first XvPut[Shm]Image. I've written a patch for SDL using the work around for this I developed for xmame (and which is still used successfully in xmame after many years of usage). I'll admit it isn't very pretty, but after investigating several possibilities this was the best option, any other fixes would need changes to the SDL api and abi.
author Sam Lantinga <slouken@libsdl.org>
date Sat, 29 Dec 2007 02:23:48 +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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><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
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><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
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><H2
>See Also</H2
><P
><A
HREF="sdlgetgammaramp.html"
>SDL_GetGammaRamp</A
>
<A
HREF="sdlsetgammaramp.html"
>SDL_SetGammaRamp</A
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