view docs/html/sdlcdstatus.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_CDStatus</TITLE
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><H1
><A
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>SDL_CDStatus</H1
><DIV
CLASS="REFNAMEDIV"
><A
NAME="AEN7308"
></A
><H2
>Name</H2
>SDL_CDStatus&nbsp;--&nbsp;Returns the current status of the given drive.</DIV
><DIV
CLASS="REFSYNOPSISDIV"
><A
NAME="AEN7311"
></A
><H2
>Synopsis</H2
><DIV
CLASS="FUNCSYNOPSIS"
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><P
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><PRE
CLASS="FUNCSYNOPSISINFO"
>#include "SDL.h"</PRE
><P
><CODE
><CODE
CLASS="FUNCDEF"
>CDstatus <B
CLASS="FSFUNC"
>SDL_CDStatus</B
></CODE
>(SDL_CD *cdrom);</CODE
></P
><PRE
CLASS="FUNCSYNOPSISINFO"
>/* Given a status, returns true if there's a disk in the drive */
#define CD_INDRIVE(status)      ((int)status &#62; 0)</PRE
><P
></P
></DIV
></DIV
><DIV
CLASS="REFSECT1"
><A
NAME="AEN7319"
></A
><H2
>Description</H2
><P
>This function returns the current status of the given drive. Status is described like so:
<PRE
CLASS="PROGRAMLISTING"
>typedef enum {
  CD_TRAYEMPTY,
  CD_STOPPED,
  CD_PLAYING,
  CD_PAUSED,
  CD_ERROR = -1
} CDstatus;</PRE
></P
><P
>If the drive has a CD in it, the table of contents of the CD and current
play position of the CD will be stored in the SDL_CD structure.</P
><P
>The macro <TT
CLASS="LITERAL"
>CD_INDRIVE</TT
> is provided for convenience, 
and given a status returns true if there's a disk in the drive.</P
><DIV
CLASS="NOTE"
><BLOCKQUOTE
CLASS="NOTE"
><P
><B
>Note: </B
><TT
CLASS="FUNCTION"
>SDL_CDStatus</TT
> also updates the <A
HREF="sdlcd.html"
><SPAN
CLASS="STRUCTNAME"
>SDL_CD</SPAN
></A
> structure passed to it.</P
></BLOCKQUOTE
></DIV
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><A
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></A
><H2
>Example</H2
><PRE
CLASS="PROGRAMLISTING"
>int playTrack(int track)
{
  int playing = 0;

  if ( CD_INDRIVE(SDL_CDStatus(cdrom)) ) {
  /* clamp to the actual number of tracks on the CD */
    if (track &#62;= cdrom-&#62;numtracks) {
      track = cdrom-&#62;numtracks-1;
    }

    if ( SDL_CDPlayTracks(cdrom, track, 0, 1, 0) == 0 ) {
      playing = 1;
    }
  }
  return playing;
}</PRE
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><A
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><H2
>See Also</H2
><P
><A
HREF="sdlcd.html"
><TT
CLASS="FUNCTION"
>SDL_CD</TT
></A
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