view docs/html/sdlvideomodeok.html @ 3880:74e828c64315 SDL-1.2

Fixed bug #292 I might be on crack here. It looks like SDL_ConvertMono() in src/audio/SDL_audiocvt.c adds the left and right channels of a stereo stream together, and clamps the new mono channel if it would overflow. Shouldn't it be dividing by 2 to average the two sample points instead of clamping? Otherwise the mono sample point's volume doubles in the conversion. This would also make the conversion faster, as it replaces two branches per sample frame with a bitwise shift. --ryan.
author Sam Lantinga <slouken@libsdl.org>
date Sun, 24 Sep 2006 15:45:37 +0000
parents 355632dca928
children
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>SDL_VideoModeOK</H1
><DIV
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><A
NAME="AEN1202"
></A
><H2
>Name</H2
>SDL_VideoModeOK&nbsp;--&nbsp;Check to see if a particular video mode is supported.</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_VideoModeOK</B
></CODE
>(int width, int height, int bpp, Uint32 flags);</CODE
></P
><P
></P
></DIV
></DIV
><DIV
CLASS="REFSECT1"
><A
NAME="AEN1212"
></A
><H2
>Description</H2
><P
><TT
CLASS="FUNCTION"
>SDL_VideoModeOK</TT
> returns <SPAN
CLASS="RETURNVALUE"
>0</SPAN
> 
if the requested mode is not supported under any bit depth, or returns the 
bits-per-pixel of the closest available mode with the given width, height and requested <A
HREF="sdlsurface.html"
>surface</A
> flags (see <A
HREF="sdlsetvideomode.html"
><TT
CLASS="FUNCTION"
>SDL_SetVideoMode</TT
></A
>).</P
><P
>The bits-per-pixel value returned is only a suggested mode. You can usually request and bpp you want when <A
HREF="sdlsetvideomode.html"
>setting</A
>  the video mode and SDL will emulate that color depth with a shadow video surface.</P
><P
>The arguments to <TT
CLASS="FUNCTION"
>SDL_VideoModeOK</TT
> are the same ones you 
would pass to <A
HREF="sdlsetvideomode.html"
>SDL_SetVideoMode</A
></P
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><H2
>Example</H2
><PRE
CLASS="PROGRAMLISTING"
>SDL_Surface *screen;
Uint32 bpp;
.
.
.
printf("Checking mode 640x480@16bpp.\n");
bpp=SDL_VideoModeOK(640, 480, 16, SDL_HWSURFACE);

if(!bpp){
  printf("Mode not available.\n");
  exit(-1);
}

printf("SDL Recommends 640x480@%dbpp.\n", bpp);
screen=SDL_SetVideoMode(640, 480, bpp, SDL_HWSURFACE);
.
.</PRE
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>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
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