view docs/man3/SDL_SetColorKey.3 @ 4223:63fd67e17705 SDL-1.2

Fixed bug #727 Lorenzo Desole 2009-04-19 07:36:10 PDT I am one of the developers of a multimedia application (My Media System MMS), which uses SDL. MMS is normally running in fullscreen mode but it switches it off before launching external applications (mplayer, xine, etc.). The problem with fullscreen is that when the latter is switched off either via SDL_WM_ToggleFullScreen() or SDL_SetVideoMode(), SDL compares the current screen sizes with the ones saved when the video system was initted, and if they don't match, it calls XF86VidModeSwitchToMode() to switch to the old modeline. This makes it impossible for external programs and for MMS itself to use RandR to change the screen size, because next time fullscreen mode is turned off, it bombs out with the following error: X Error of failed request: BadValue (integer parameter out of range for operation) Major opcode of failed request: 136 (XFree86-VidModeExtension) Minor opcode of failed request: 10 (XF86VidModeSwitchToMode) [...] Obviously this happens only if the new screen resolution is smaller than the original one and XF86VidModeSwitchToMode() can't succeed. I couldn't find any way to inform SDL that the screen resolution it uses as reference is no longer valid. This can be fixed by adding "save_mode(this)" to ./src/video/x11/SDL_x11modes.c, API X11_EnterFullScreen(_THIS), like this: int X11_EnterFullScreen(_THIS) { int okay; + save_mode(this); I can't rule out possible side effects, but I don't see any. While I admit this is a minor issue for the general users, it is a major showstopper for our program where the ability to change screen resolution and refresh rate according to the movie being played, is very important. Thanks in advance.
author Sam Lantinga <slouken@libsdl.org>
date Mon, 21 Sep 2009 11:14:36 +0000
parents 4e3b250c950e
children 1238da4a7112
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.TH "SDL_SetColorKey" "3" "Tue 11 Sep 2001, 23:01" "SDL" "SDL API Reference" 
.SH "NAME"
SDL_SetColorKey \- Sets the color key (transparent pixel) in a blittable surface and RLE acceleration\&.
.SH "SYNOPSIS"
.PP
\fB#include "SDL\&.h"
.sp
\fBint \fBSDL_SetColorKey\fP\fR(\fBSDL_Surface *surface, Uint32 flag, Uint32 key\fR);
.SH "DESCRIPTION"
.PP
 Sets the color key (transparent pixel) in a blittable surface and enables or disables RLE blit acceleration\&.
.PP
RLE acceleration can substantially speed up blitting of images with large horizontal runs of transparent pixels (i\&.e\&., pixels that match the \fBkey\fR value)\&. The \fBkey\fR must be of the same pixel format as the \fBsurface\fR, \fI\fBSDL_MapRGB\fP\fR is often useful for obtaining an acceptable value\&.
.PP
If \fBflag\fR is \fBSDL_SRCCOLORKEY\fP then \fBkey\fR is the transparent pixel value in the source image of a blit\&.
.PP
If \fBflag\fR is OR\&'d with \fBSDL_RLEACCEL\fP then the surface will be draw using RLE acceleration when drawn with \fISDL_BlitSurface\fR\&. The surface will actually be encoded for RLE acceleration the first time \fISDL_BlitSurface\fR or \fISDL_DisplayFormat\fR is called on the surface\&.
.PP
If \fBflag\fR is 0, this function clears any current color key\&.
.SH "RETURN VALUE"
.PP
This function returns \fB0\fR, or \fB-1\fR if there was an error\&.
.SH "SEE ALSO"
.PP
\fI\fBSDL_BlitSurface\fP\fR, \fI\fBSDL_DisplayFormat\fP\fR, \fI\fBSDL_MapRGB\fP\fR, \fI\fBSDL_SetAlpha\fP\fR
...\" created by instant / docbook-to-man, Tue 11 Sep 2001, 23:01