view docs/html/sdlflip.html @ 717:42ed44b2c8b6

Date: Sun, 14 Sep 2003 17:04:55 -0400 From: Philip D.S. Thoren <pthoren@cs.uml.edu> Reply-To: "sdl@libsdl.org" <sdl@libsdl.org> To: "sdl@libsdl.org" <sdl@libsdl.org> Subject: [SDL] BUG in src/video/windx5/SDL_dx5events.c I tracked down a bug that crashed my program on Windows *all* the time. FILE: src/video/windx5/SDL_dx5events.c FUNCTION: handle_mouse BUG: SDL_PublicSurface is being dereferenced when it is NULL. I added the following to the very begining of handle_mouse and it solved my crashing problems: if (SDL_PublicSurface == NULL) return; ~ Philip D.S. Thoren
author Ryan C. Gordon <icculus@icculus.org>
date Mon, 15 Sep 2003 13:51:25 +0000
parents e5bc29de3f0a
children 355632dca928
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<HTML
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>SDL_Flip</TITLE
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><H1
><A
NAME="SDLFLIP"
>SDL_Flip</A
></H1
><DIV
CLASS="REFNAMEDIV"
><A
NAME="AEN1042"
></A
><H2
>Name</H2
>SDL_Flip&nbsp;--&nbsp;Swaps screen buffers</DIV
><DIV
CLASS="REFSYNOPSISDIV"
><A
NAME="AEN1045"
></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"
>int <B
CLASS="FSFUNC"
>SDL_Flip</B
></CODE
>(SDL_Surface *screen);</CODE
></P
><P
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><DIV
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><A
NAME="AEN1052"
></A
><H2
>Description</H2
><P
>On hardware that supports double-buffering, this function sets up a flip
and returns.  The hardware will wait for vertical retrace, and then swap
video buffers before the next video surface blit or lock will return.
On hardware that doesn't support double-buffering, this is equivalent
to calling <A
HREF="sdlupdaterect.html"
>SDL_UpdateRect</A
><TT
CLASS="PARAMETER"
><I
>(screen, 0, 0, 0, 0)</I
></TT
></P
><P
>The <TT
CLASS="LITERAL"
>SDL_DOUBLEBUF</TT
> flag must have been passed to 
<A
HREF="sdlsetvideomode.html"
>SDL_SetVideoMode</A
>,
 when
setting the video mode for this function to perform hardware flipping.</P
></DIV
><DIV
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><A
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></A
><H2
>Return Value</H2
><P
>This function returns <SPAN
CLASS="RETURNVALUE"
>0</SPAN
> if successful, or 
<SPAN
CLASS="RETURNVALUE"
>-1</SPAN
> if there was an error.</P
></DIV
><DIV
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><A
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></A
><H2
>See Also</H2
><P
><A
HREF="sdlsetvideomode.html"
><TT
CLASS="FUNCTION"
>SDL_SetVideoMode</TT
></A
>,
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HREF="sdlupdaterect.html"
><TT
CLASS="FUNCTION"
>SDL_UpdateRect</TT
></A
>,
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HREF="sdlsurface.html"
><SPAN
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>SDL_Surface</SPAN
></A
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