Mercurial > sdl-ios-xcode
view docs/html/sdlsetvideomode.html @ 4168:69bcba65c388 SDL-1.2
Fixed bug #526
Comment #1 From Simon Howard 2009-03-20 16:50:56
Hi,
I'm the author of Chocolate Doom, one of the other source ports that James
mentioned. This is a patch against the current SVN version of SDL 1.2 that
fixes the bug. It has been tested and hopefully should be obviously correct
from examining the changes. I'll give a brief explanation.
When the palette is set with SDL_SetPalette, the IDirectDrawPalette_SetEntries
DirectX function is invoked. However, when this happens, a WM_PALETTECHANGED
message is sent to the window.
A WM_PALETTECHANGED message can also be received if the palette is changed for
some other reason, like if the system palette is changed. Therefore, the
palette change handler (DX5_PaletteChanged) has code to deal with this case.
It distinguishes "expected" palette changes (set with SDL_SetPalette) from
"unexpected" palette changes using the colorchange_expected variable, which is
set before calling IDirectDrawPalette_SetEntries. However, the code to set
this variable is missing in the fullscreen code path. By setting this
variable, the palette change is handled properly and the freezes go away.
author | Sam Lantinga <slouken@libsdl.org> |
---|---|
date | Mon, 13 Apr 2009 00:53:12 +0000 |
parents | 355632dca928 |
children |
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<HTML ><HEAD ><TITLE >SDL_SetVideoMode</TITLE ><META NAME="GENERATOR" CONTENT="Modular DocBook HTML Stylesheet Version 1.76b+ "><LINK REL="HOME" TITLE="SDL Library Documentation" HREF="index.html"><LINK REL="UP" TITLE="Video" HREF="video.html"><LINK REL="PREVIOUS" TITLE="SDL_VideoModeOK" HREF="sdlvideomodeok.html"><LINK REL="NEXT" TITLE="SDL_UpdateRect" HREF="sdlupdaterect.html"></HEAD ><BODY CLASS="REFENTRY" BGCOLOR="#FFF8DC" TEXT="#000000" LINK="#0000ee" VLINK="#551a8b" ALINK="#ff0000" ><DIV CLASS="NAVHEADER" ><TABLE SUMMARY="Header navigation table" WIDTH="100%" BORDER="0" CELLPADDING="0" CELLSPACING="0" ><TR ><TH COLSPAN="3" ALIGN="center" >SDL Library Documentation</TH ></TR ><TR ><TD WIDTH="10%" ALIGN="left" VALIGN="bottom" ><A HREF="sdlvideomodeok.html" ACCESSKEY="P" >Prev</A ></TD ><TD WIDTH="80%" ALIGN="center" VALIGN="bottom" ></TD ><TD WIDTH="10%" ALIGN="right" VALIGN="bottom" ><A HREF="sdlupdaterect.html" ACCESSKEY="N" >Next</A ></TD ></TR ></TABLE ><HR ALIGN="LEFT" WIDTH="100%"></DIV ><H1 ><A NAME="SDLSETVIDEOMODE" ></A >SDL_SetVideoMode</H1 ><DIV CLASS="REFNAMEDIV" ><A NAME="AEN1239" ></A ><H2 >Name</H2 >SDL_SetVideoMode -- Set up a video mode with the specified width, height and bits-per-pixel.</DIV ><DIV CLASS="REFSYNOPSISDIV" ><A NAME="AEN1242" ></A ><H2 >Synopsis</H2 ><DIV CLASS="FUNCSYNOPSIS" ><A NAME="AEN1243" ></A ><P ></P ><PRE CLASS="FUNCSYNOPSISINFO" >#include "SDL.h"</PRE ><P ><CODE ><CODE CLASS="FUNCDEF" >SDL_Surface *<B CLASS="FSFUNC" >SDL_SetVideoMode</B ></CODE >(int width, int height, int bpp, Uint32 flags);</CODE ></P ><P ></P ></DIV ></DIV ><DIV CLASS="REFSECT1" ><A NAME="AEN1249" ></A ><H2 >Description</H2 ><P >Set up a video mode with the specified width, height and bits-per-pixel.</P ><P >If <TT CLASS="PARAMETER" ><I >bpp</I ></TT > is 0, it is treated as the current display bits per pixel.</P ><P >The <TT CLASS="PARAMETER" ><I >flags</I ></TT > parameter is the same as the <TT CLASS="STRUCTFIELD" ><I >flags</I ></TT > field of the <A HREF="sdlsurface.html" ><SPAN CLASS="STRUCTNAME" >SDL_Surface</SPAN ></A > structure. OR'd combinations of the following values are valid.</P ><DIV CLASS="INFORMALTABLE" ><A NAME="AEN1259" ></A ><P ></P ><TABLE BORDER="1" CLASS="CALSTABLE" ><TBODY ><TR ><TD ALIGN="LEFT" VALIGN="TOP" ><TT CLASS="LITERAL" >SDL_SWSURFACE</TT ></TD ><TD ALIGN="LEFT" VALIGN="TOP" >Create the video surface in system memory</TD ></TR ><TR ><TD ALIGN="LEFT" VALIGN="TOP" ><TT CLASS="LITERAL" >SDL_HWSURFACE</TT ></TD ><TD ALIGN="LEFT" VALIGN="TOP" >Create the video surface in video memory</TD ></TR ><TR ><TD ALIGN="LEFT" VALIGN="TOP" ><TT CLASS="LITERAL" >SDL_ASYNCBLIT</TT ></TD ><TD ALIGN="LEFT" VALIGN="TOP" >Enables the use of asynchronous updates of the display surface. This will usually slow down blitting on single CPU machines, but may provide a speed increase on SMP systems.</TD ></TR ><TR ><TD ALIGN="LEFT" VALIGN="TOP" ><TT CLASS="LITERAL" >SDL_ANYFORMAT</TT ></TD ><TD ALIGN="LEFT" VALIGN="TOP" >Normally, if a video surface of the requested bits-per-pixel (<TT CLASS="PARAMETER" ><I >bpp</I ></TT >) is not available, SDL will emulate one with a shadow surface. Passing <TT CLASS="LITERAL" >SDL_ANYFORMAT</TT > prevents this and causes SDL to use the video surface, regardless of its pixel depth.</TD ></TR ><TR ><TD ALIGN="LEFT" VALIGN="TOP" ><TT CLASS="LITERAL" >SDL_HWPALETTE</TT ></TD ><TD ALIGN="LEFT" VALIGN="TOP" >Give SDL exclusive palette access. Without this flag you may not always get the the colors you request with <A HREF="sdlsetcolors.html" ><TT CLASS="FUNCTION" >SDL_SetColors</TT ></A > or <A HREF="sdlsetpalette.html" ><TT CLASS="FUNCTION" >SDL_SetPalette</TT ></A >.</TD ></TR ><TR ><TD ALIGN="LEFT" VALIGN="TOP" ><TT CLASS="LITERAL" >SDL_DOUBLEBUF</TT ></TD ><TD ALIGN="LEFT" VALIGN="TOP" >Enable hardware double buffering; only valid with SDL_HWSURFACE. Calling <A HREF="sdlflip.html" ><TT CLASS="FUNCTION" >SDL_Flip</TT ></A > will flip the buffers and update the screen. All drawing will take place on the surface that is not displayed at the moment. If double buffering could not be enabled then <TT CLASS="FUNCTION" >SDL_Flip</TT > will just perform a <A HREF="sdlupdaterect.html" ><TT CLASS="FUNCTION" >SDL_UpdateRect</TT ></A > on the entire screen.</TD ></TR ><TR ><TD ALIGN="LEFT" VALIGN="TOP" ><TT CLASS="LITERAL" >SDL_FULLSCREEN</TT ></TD ><TD ALIGN="LEFT" VALIGN="TOP" >SDL will attempt to use a fullscreen mode. If a hardware resolution change is not possible (for whatever reason), the next higher resolution will be used and the display window centered on a black background.</TD ></TR ><TR ><TD ALIGN="LEFT" VALIGN="TOP" ><TT CLASS="LITERAL" >SDL_OPENGL</TT ></TD ><TD ALIGN="LEFT" VALIGN="TOP" >Create an OpenGL rendering context. You should have previously set OpenGL video attributes with <A HREF="sdlglsetattribute.html" ><TT CLASS="FUNCTION" >SDL_GL_SetAttribute</TT ></A >.</TD ></TR ><TR ><TD ALIGN="LEFT" VALIGN="TOP" ><TT CLASS="LITERAL" >SDL_OPENGLBLIT</TT ></TD ><TD ALIGN="LEFT" VALIGN="TOP" >Create an OpenGL rendering context, like above, but allow normal blitting operations. The screen (2D) surface may have an alpha channel, and <A HREF="sdlupdaterects.html" ><TT CLASS="FUNCTION" >SDL_UpdateRects</TT ></A > must be used for updating changes to the screen surface. NOTE: This option is kept for compatibility only, and is <SPAN CLASS="emphasis" ><I CLASS="EMPHASIS" >not</I ></SPAN > recommended for new code.</TD ></TR ><TR ><TD ALIGN="LEFT" VALIGN="TOP" ><TT CLASS="LITERAL" >SDL_RESIZABLE</TT ></TD ><TD ALIGN="LEFT" VALIGN="TOP" >Create a resizable window. When the window is resized by the user a <A HREF="sdlresizeevent.html" ><TT CLASS="LITERAL" >SDL_VIDEORESIZE</TT ></A > event is generated and <TT CLASS="FUNCTION" >SDL_SetVideoMode</TT > can be called again with the new size.</TD ></TR ><TR ><TD ALIGN="LEFT" VALIGN="TOP" ><TT CLASS="LITERAL" >SDL_NOFRAME</TT ></TD ><TD ALIGN="LEFT" VALIGN="TOP" >If possible, <TT CLASS="LITERAL" >SDL_NOFRAME</TT > causes SDL to create a window with no title bar or frame decoration. Fullscreen modes automatically have this flag set.</TD ></TR ></TBODY ></TABLE ><P ></P ></DIV ><DIV CLASS="NOTE" ><BLOCKQUOTE CLASS="NOTE" ><P ><B >Note: </B >Whatever <TT CLASS="PARAMETER" ><I >flags</I ></TT > <TT CLASS="FUNCTION" >SDL_SetVideoMode</TT > could satisfy are set in the <TT CLASS="STRUCTFIELD" ><I >flags</I ></TT > member of the returned surface.</P ></BLOCKQUOTE ></DIV ><DIV CLASS="NOTE" ><BLOCKQUOTE CLASS="NOTE" ><P ><B >Note: </B >The <TT CLASS="PARAMETER" ><I >bpp</I ></TT > parameter is the number of bits per pixel, so a <TT CLASS="PARAMETER" ><I >bpp</I ></TT > of 24 uses the packed representation of 3 bytes/pixel. For the more common 4 bytes/pixel mode, use a <TT CLASS="PARAMETER" ><I >bpp</I ></TT > of 32. Somewhat oddly, both 15 and 16 will request a 2 bytes/pixel mode, but different pixel formats.</P ></BLOCKQUOTE ></DIV ></DIV ><DIV CLASS="REFSECT1" ><A NAME="AEN1336" ></A ><H2 >Return Value</H2 ><P >The framebuffer surface, or <SPAN CLASS="RETURNVALUE" >NULL</SPAN > if it fails. The surface returned is freed by SDL_Quit() and should nt be freed by the caller.</P ></DIV ><DIV CLASS="REFSECT1" ><A NAME="AEN1340" ></A ><H2 >See Also</H2 ><P ><A HREF="sdllocksurface.html" ><TT CLASS="FUNCTION" >SDL_LockSurface</TT ></A >, <A HREF="sdlsetcolors.html" ><TT CLASS="FUNCTION" >SDL_SetColors</TT ></A >, <A HREF="sdlflip.html" ><TT CLASS="FUNCTION" >SDL_Flip</TT ></A >, <A HREF="sdlsurface.html" ><SPAN CLASS="STRUCTNAME" >SDL_Surface</SPAN ></A ></P ></DIV ><DIV CLASS="NAVFOOTER" ><HR ALIGN="LEFT" WIDTH="100%"><TABLE SUMMARY="Footer navigation table" WIDTH="100%" BORDER="0" CELLPADDING="0" CELLSPACING="0" ><TR ><TD WIDTH="33%" ALIGN="left" VALIGN="top" ><A HREF="sdlvideomodeok.html" ACCESSKEY="P" >Prev</A ></TD ><TD WIDTH="34%" ALIGN="center" VALIGN="top" ><A HREF="index.html" ACCESSKEY="H" >Home</A ></TD ><TD WIDTH="33%" ALIGN="right" VALIGN="top" ><A HREF="sdlupdaterect.html" ACCESSKEY="N" >Next</A ></TD ></TR ><TR ><TD WIDTH="33%" ALIGN="left" VALIGN="top" >SDL_VideoModeOK</TD ><TD WIDTH="34%" ALIGN="center" VALIGN="top" ><A HREF="video.html" ACCESSKEY="U" >Up</A ></TD ><TD WIDTH="33%" ALIGN="right" VALIGN="top" >SDL_UpdateRect</TD ></TR ></TABLE ></DIV ></BODY ></HTML >