Mercurial > sdl-ios-xcode
view docs/man3/SDL_AddTimer.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reference is no longer valid.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_AddTimer" "3" "Tue 11 Sep 2001, 23:01" "SDL" "SDL API Reference" .SH "NAME" SDL_AddTimer \- Add a timer which will call a callback after the specified number of milliseconds has elapsed\&. .SH "SYNOPSIS" .PP \fB#include "SDL\&.h" .sp \fBSDL_TimerID \fBSDL_AddTimer\fP\fR(\fBUint32 interval, SDL_NewTimerCallback callback, void *param\fR); .SH "CALLBACK" .PP .nf \f(CW/* type definition for the "new" timer callback function */ typedef Uint32 (*SDL_NewTimerCallback)(Uint32 interval, void *param);\fR .fi .PP .SH "DESCRIPTION" .PP Adds a callback function to be run after the specified number of milliseconds has elapsed\&. The callback function is passed the current timer interval and the user supplied parameter from the \fBSDL_AddTimer\fP call and returns the next timer interval\&. If the returned value from the callback is the same as the one passed in, the periodic alarm continues, otherwise a new alarm is scheduled\&. .PP To cancel a currently running timer call \fISDL_RemoveTimer\fR with the timer ID returned from \fBSDL_AddTimer\fP\&. .PP The timer callback function may run in a different thread than your main program, and so shouldn\&'t call any functions from within itself\&. You may always call \fISDL_PushEvent\fR, however\&. .PP The granularity of the timer is platform-dependent, but you should count on it being at least 10 ms as this is the most common number\&. This means that if you request a 16 ms timer, your callback will run approximately 20 ms later on an unloaded system\&. If you wanted to set a flag signaling a frame update at 30 frames per second (every 33 ms), you might set a timer for 30 ms (see example below)\&. If you use this function, you need to pass \fBSDL_INIT_TIMER\fP to \fISDL_Init\fR\&. .SH "RETURN VALUE" .PP Returns an ID value for the added timer or \fBNULL\fR if there was an error\&. .SH "EXAMPLES" .PP .PP .nf \f(CWmy_timer_id = SDL_AddTimer((33/10)*10, my_callbackfunc, my_callback_param);\fR .fi .PP .SH "SEE ALSO" .PP \fI\fBSDL_RemoveTimer\fP\fR, \fI\fBSDL_PushEvent\fP\fR ...\" created by instant / docbook-to-man, Tue 11 Sep 2001, 23:01