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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
children
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<HTML
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><TITLE
>SDL_SetColorKey</TITLE
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><H1
><A
NAME="SDLSETCOLORKEY"
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>SDL_SetColorKey</H1
><DIV
CLASS="REFNAMEDIV"
><A
NAME="AEN2045"
></A
><H2
>Name</H2
>SDL_SetColorKey&nbsp;--&nbsp;Sets the color key (transparent pixel) in a blittable surface and
RLE acceleration.</DIV
><DIV
CLASS="REFSYNOPSISDIV"
><A
NAME="AEN2048"
></A
><H2
>Synopsis</H2
><DIV
CLASS="FUNCSYNOPSIS"
><A
NAME="AEN2049"
></A
><P
></P
><PRE
CLASS="FUNCSYNOPSISINFO"
>#include "SDL.h"</PRE
><P
><CODE
><CODE
CLASS="FUNCDEF"
>int <B
CLASS="FSFUNC"
>SDL_SetColorKey</B
></CODE
>(SDL_Surface *surface, Uint32 flag, Uint32 key);</CODE
></P
><P
></P
></DIV
></DIV
><DIV
CLASS="REFSECT1"
><A
NAME="AEN2055"
></A
><H2
>Description</H2
><P
> Sets the color key (transparent pixel) in a blittable surface and enables or
 disables RLE blit acceleration.</P
><P
>RLE acceleration can substantially speed up blitting of images with large
horizontal runs of transparent pixels (i.e., pixels that match the
<TT
CLASS="PARAMETER"
><I
>key</I
></TT
> value). The <TT
CLASS="PARAMETER"
><I
>key</I
></TT
> must be of the same pixel format as the <TT
CLASS="PARAMETER"
><I
>surface</I
></TT
>, <A
HREF="sdlmaprgb.html"
><TT
CLASS="FUNCTION"
>SDL_MapRGB</TT
></A
> is often useful for obtaining an acceptable value.</P
><P
>If <TT
CLASS="PARAMETER"
><I
>flag</I
></TT
> is <TT
CLASS="LITERAL"
>SDL_SRCCOLORKEY</TT
> then
<TT
CLASS="PARAMETER"
><I
>key</I
></TT
> is the transparent pixel value in the source image of a
blit.</P
><P
>If <TT
CLASS="PARAMETER"
><I
>flag</I
></TT
> is OR'd with
<TT
CLASS="LITERAL"
>SDL_RLEACCEL</TT
> then the surface will be draw using RLE
acceleration when drawn with
<A
HREF="sdlblitsurface.html"
>SDL_BlitSurface</A
>.  The surface will
actually be encoded for RLE acceleration the first time
<A
HREF="sdlblitsurface.html"
>SDL_BlitSurface</A
> or
<A
HREF="sdldisplayformat.html"
>SDL_DisplayFormat</A
> is called on the
surface.</P
><P
>If <TT
CLASS="PARAMETER"
><I
>flag</I
></TT
> is 0, this function clears
any current color key.</P
></DIV
><DIV
CLASS="REFSECT1"
><A
NAME="AEN2076"
></A
><H2
>Return Value</H2
><P
>This function returns <SPAN
CLASS="RETURNVALUE"
>0</SPAN
>, or
<SPAN
CLASS="RETURNVALUE"
>-1</SPAN
> if there was an error.</P
></DIV
><DIV
CLASS="REFSECT1"
><A
NAME="AEN2081"
></A
><H2
>See Also</H2
><P
><A
HREF="sdlblitsurface.html"
><TT
CLASS="FUNCTION"
>SDL_BlitSurface</TT
></A
>,
<A
HREF="sdldisplayformat.html"
><TT
CLASS="FUNCTION"
>SDL_DisplayFormat</TT
></A
>,
<A
HREF="sdlmaprgb.html"
><TT
CLASS="FUNCTION"
>SDL_MapRGB</TT
></A
>,
<A
HREF="sdlsetalpha.html"
><TT
CLASS="FUNCTION"
>SDL_SetAlpha</TT
></A
></P
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