view docs/man3/SDL_SetVideoMode.3 @ 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 4e3b250c950e
children 1238da4a7112
line wrap: on
line source

.TH "SDL_SetVideoMode" "3" "Tue 11 Sep 2001, 23:01" "SDL" "SDL API Reference" 
.SH "NAME"
SDL_SetVideoMode \- Set up a video mode with the specified width, height and bits-per-pixel\&.
.SH "SYNOPSIS"
.PP
\fB#include "SDL\&.h"
.sp
\fBSDL_Surface *\fBSDL_SetVideoMode\fP\fR(\fBint width, int height, int bpp, Uint32 flags\fR);
.SH "DESCRIPTION"
.PP
Set up a video mode with the specified width, height and bits-per-pixel\&.
.PP
If \fBbpp\fR is 0, it is treated as the current display bits per pixel\&.
.PP
The \fBflags\fR parameter is the same as the \fBflags\fR field of the \fI\fBSDL_Surface\fR\fR structure\&. OR\&'d combinations of the following values are valid\&.
.TP 20
\fBSDL_SWSURFACE\fP
Create the video surface in system memory
.TP 20
\fBSDL_HWSURFACE\fP
Create the video surface in video memory
.TP 20
\fBSDL_ASYNCBLIT\fP
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\&.
.TP 20
\fBSDL_ANYFORMAT\fP
Normally, if a video surface of the requested bits-per-pixel (\fBbpp\fR) is not available, SDL will emulate one with a shadow surface\&. Passing \fBSDL_ANYFORMAT\fP prevents this and causes SDL to use the video surface, regardless of its pixel depth\&.
.TP 20
\fBSDL_HWPALETTE\fP
Give SDL exclusive palette access\&. Without this flag you may not always get the the colors you request with \fI\fBSDL_SetColors\fP\fR or \fI\fBSDL_SetPalette\fP\fR\&.
.TP 20
\fBSDL_DOUBLEBUF\fP
Enable hardware double buffering; only valid with SDL_HWSURFACE\&. Calling \fI\fBSDL_Flip\fP\fR 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 \fBSDL_Flip\fP will just perform a \fI\fBSDL_UpdateRect\fP\fR on the entire screen\&.
.TP 20
\fBSDL_FULLSCREEN\fP
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\&.
.TP 20
\fBSDL_OPENGL\fP
Create an OpenGL rendering context\&. You should have previously set OpenGL video attributes with \fI\fBSDL_GL_SetAttribute\fP\fR\&.
.TP 20
\fBSDL_OPENGLBLIT\fP
Create an OpenGL rendering context, like above, but allow normal blitting operations\&. The screen (2D) surface may have an alpha channel, and \fI\fBSDL_UpdateRects\fP\fR must be used for updating changes to the screen surface\&.
.TP 20
\fBSDL_RESIZABLE\fP
Create a resizable window\&. When the window is resized by the user a \fI\fBSDL_VIDEORESIZE\fP\fR event is generated and \fBSDL_SetVideoMode\fP can be called again with the new size\&.
.TP 20
\fBSDL_NOFRAME\fP
If possible, \fBSDL_NOFRAME\fP causes SDL to create a window with no title bar or frame decoration\&. Fullscreen modes automatically have this flag set\&.
.PP
.RS
\fBNote:  
.PP
Whatever \fBflags\fR \fBSDL_SetVideoMode\fP could satisfy are set in the \fBflags\fR member of the returned surface\&.
.RE
.PP
.RS
\fBNote:  
.PP
The \fBbpp\fR parameter is the number of bits per pixel, so a \fBbpp\fR of 24 uses the packed representation of 3 bytes/pixel\&. For the more common 4 bytes/pixel mode, use a \fBbpp\fR of 32\&. Somewhat oddly, both 15 and 16 will request a 2 bytes/pixel mode, but different pixel formats\&.
.RE
.SH "RETURN VALUE"
.PP
The framebuffer surface, or \fBNULL\fR if it fails\&. The surface returned is freed by SDL_Quit() and should nt be freed by the caller\&.
.SH "SEE ALSO"
.PP
\fI\fBSDL_LockSurface\fP\fR, \fI\fBSDL_SetColors\fP\fR, \fI\fBSDL_Flip\fP\fR, \fI\fBSDL_Surface\fR\fR
...\" created by instant / docbook-to-man, Tue 11 Sep 2001, 23:01