view docs/html/sdllistmodes.html @ 883:50f5a29c6a17

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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>SDL_ListModes</TITLE
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><H1
><A
NAME="SDLLISTMODES"
></A
>SDL_ListModes</H1
><DIV
CLASS="REFNAMEDIV"
><A
NAME="AEN1159"
></A
><H2
>Name</H2
>SDL_ListModes&nbsp;--&nbsp;Returns a pointer to an array of available screen dimensions for 
the given format and video flags</DIV
><DIV
CLASS="REFSYNOPSISDIV"
><A
NAME="AEN1162"
></A
><H2
>Synopsis</H2
><DIV
CLASS="FUNCSYNOPSIS"
><A
NAME="AEN1163"
></A
><P
></P
><PRE
CLASS="FUNCSYNOPSISINFO"
>#include "SDL.h"</PRE
><P
><CODE
><CODE
CLASS="FUNCDEF"
>SDL_Rect **<B
CLASS="FSFUNC"
>SDL_ListModes</B
></CODE
>(SDL_PixelFormat *format, Uint32 flags);</CODE
></P
><P
></P
></DIV
></DIV
><DIV
CLASS="REFSECT1"
><A
NAME="AEN1169"
></A
><H2
>Description</H2
><P
>Return a pointer to an array of available screen dimensions for the given
format and video flags, sorted largest to smallest.  Returns
<TT
CLASS="LITERAL"
>NULL</TT
> if there are no dimensions available for a particular
format, or <SPAN
CLASS="RETURNVALUE"
>-1</SPAN
> if any dimension is okay for
the given format.</P
><P
>If <TT
CLASS="PARAMETER"
><I
>format</I
></TT
> is <TT
CLASS="LITERAL"
>NULL</TT
>, the mode list
will be for the format returned by <A
HREF="sdlgetvideoinfo.html"
>SDL_GetVideoInfo()</A
>-&#62;<TT
CLASS="STRUCTFIELD"
><I
>vfmt</I
></TT
>. The <TT
CLASS="PARAMETER"
><I
>flag</I
></TT
> parameter is an OR'd combination of <A
HREF="sdlsurface.html"
>surface</A
> flags. The flags are the same as those used <A
HREF="sdlsetvideomode.html"
><TT
CLASS="FUNCTION"
>SDL_SetVideoMode</TT
></A
> and they play a strong role in deciding what modes are valid. For instance, if you pass <TT
CLASS="LITERAL"
>SDL_HWSURFACE</TT
> as a flag only modes that support hardware video surfaces will be returned.</P
></DIV
><DIV
CLASS="REFSECT1"
><A
NAME="AEN1184"
></A
><H2
>Example</H2
><PRE
CLASS="PROGRAMLISTING"
>SDL_Rect **modes;
int i;
.
.
.

/* Get available fullscreen/hardware modes */
modes=SDL_ListModes(NULL, SDL_FULLSCREEN|SDL_HWSURFACE);

/* Check is there are any modes available */
if(modes == (SDL_Rect **)0){
  printf("No modes available!\n");
  exit(-1);
}

/* Check if our resolution is restricted */
if(modes == (SDL_Rect **)-1){
  printf("All resolutions available.\n");
}
else{
  /* Print valid modes */
  printf("Available Modes\n");
  for(i=0;modes[i];++i)
    printf("  %d x %d\n", modes[i]-&#62;w, modes[i]-&#62;h);
}
.
.</PRE
></DIV
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><A
NAME="AEN1187"
></A
><H2
>See Also</H2
><P
><A
HREF="sdlsetvideomode.html"
><TT
CLASS="FUNCTION"
>SDL_SetVideoMode</TT
></A
>,
<A
HREF="sdlgetvideoinfo.html"
><TT
CLASS="FUNCTION"
>SDL_GetVideoInfo</TT
></A
>,
<A
HREF="sdlrect.html"
><SPAN
CLASS="STRUCTNAME"
>SDL_Rect</SPAN
></A
>,
<A
HREF="sdlpixelformat.html"
><SPAN
CLASS="STRUCTNAME"
>SDL_PixelFormat</SPAN
></A
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