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Date: Sat, 10 Apr 2004 02:25:33 -0400 From: Glenn Maynard To: sdl@libsdl.org Subject: [SDL] SDL_SetVideoMode() failing and not setting an error (patch) Running an OpenGL SDL application off 1.2.7, at SDL_InitSubSystem(SDL_INIT_VIDEO) time: Warning: Unable to initialize AAlib mouseUsing AAlib driver: Slang driver 1.0 (slang) SDL_SetVideoMode then fails; SDL_GetError() returns "". The installation problem is straightforward: X (the higher priority driver) isn't running, so SDL is falling back on aalib. However, no error is being set when aalib fails to initialize. This also happens with the svgalib driver. SDL_video.c line ~653 sets mode to NULL, since aalib didn't return an OpenGL surface. Line ~711 ("failed setting a video mode") returns NULL. The attached patch sets an error. It's a horrible, useless error message--it should really say eg. "aalib does not support OpenGL"; this should probably be done earlier in the individual drivers, too.
author Sam Lantinga <slouken@libsdl.org>
date Sun, 11 Apr 2004 19:54:40 +0000
parents 355632dca928
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>SDL_SetGammaRamp</TITLE
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><H1
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>SDL_SetGammaRamp</H1
><DIV
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><A
NAME="AEN1624"
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><H2
>Name</H2
>SDL_SetGammaRamp&nbsp;--&nbsp;Sets the color gamma lookup tables for the display</DIV
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>Synopsis</H2
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><PRE
CLASS="FUNCSYNOPSISINFO"
>#include "SDL.h"</PRE
><P
><CODE
><CODE
CLASS="FUNCDEF"
>int <B
CLASS="FSFUNC"
>SDL_SetGammaRamp</B
></CODE
>(Uint16 *redtable, Uint16 *greentable, Uint16 *bluetable);</CODE
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><H2
>Description</H2
><P
>Sets the gamma lookup tables for the display for each color component.
Each table is an array of 256 Uint16 values, representing a mapping
between the input and output for that channel. The input is the index
into the array, and the output is the 16-bit gamma value at that index,
scaled to the output color precision. You may pass NULL to any of the
channels to leave them unchanged.</P
><P
>This function adjusts the gamma based on lookup tables, you can also
have the gamma calculated based on a "gamma function" parameter with
<A
HREF="sdlsetgamma.html"
>SDL_SetGamma</A
>.</P
><P
>Not all display hardware is able to change gamma.</P
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><H2
>Return Value</H2
><P
>Returns -1 on error (or if gamma adjustment is not supported).</P
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><H2
>See Also</H2
><P
><A
HREF="sdlsetgamma.html"
>SDL_SetGamma</A
>
<A
HREF="sdlgetgammaramp.html"
>SDL_GetGammaRamp</A
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