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Fixed bug #898 Jeremiah Morris 2009-12-09 16:07:17 PST No-op GlobalToLocal translations in fullscreen mode On my MacBook Pro running 10.6, I noticed a small upward bias on mouse movement in a fullscreen SDL application. The app uses WarpCursor and GetMouseState in a loop to measure relative movement. I tracked it down to NSWindow's convertBaseToScreen: routine, which added a 2-pixel offset on the Y coordinate instead of the expected (+0,+0) translation. In fullscreen mode, QZ_PrivateWarpCursor() does not translate the desired position through QZ_PrivateGlobalToLocal() before passing it to the Core Graphics system. However, QZ_GetMouseLocation() does call the reverse QZ_PrivateLocalToGlobal() even in fullscreen mode. This asymmetry caused problems each time the mouse was moved.
author Sam Lantinga <slouken@libsdl.org>
date Fri, 11 Dec 2009 15:31:37 +0000
parents 1238da4a7112
children
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.TH "SDL_SemWaitTimeout" "3" "Tue 11 Sep 2001, 23:00" "SDL" "SDL API Reference" 
.SH "NAME"
SDL_SemWaitTimeout \- Lock a semaphore, but only wait up to a specified maximum time\&.
.SH "SYNOPSIS"
.PP
\fB#include "SDL\&.h"
#include "SDL_thread\&.h"
.sp
\fBint \fBSDL_SemWaitTimeout\fP\fR(\fBSDL_sem *sem, Uint32 timeout\fR);
.SH "DESCRIPTION"
.PP
\fBSDL_SemWaitTimeout()\fP is a varient of \fISDL_SemWait\fR with a maximum timeout value\&. If the value of the semaphore pointed to by \fBsem\fR is positive (greater than zero) it will atomically decrement the semaphore value and return 0, otherwise it will wait up to \fBtimeout\fR milliseconds trying to lock the semaphore\&. This function is to be avoided if possible since on some platforms it is implemented by polling the semaphore every millisecond in a busy loop\&.
.PP
After \fBSDL_SemWaitTimeout()\fP is successful, the semaphore can be released and its count atomically incremented by a successful call to \fISDL_SemPost\fR\&.
.SH "RETURN VALUE"
.PP
Returns \fB0\fR if the semaphore was successfully locked or either \fBSDL_MUTEX_TIMEOUT\fR or \fB-1\fR if the timeout period was exceeded or there was an error, respectivly\&.
.PP
If the semaphore was not successfully locked, the semaphore will be unchanged\&.
.SH "EXAMPLES"
.PP
.PP
.nf
\f(CWres = SDL_SemWaitTimeout(my_sem, WAIT_TIMEOUT_MILLISEC);

if (res == SDL_MUTEX_TIMEOUT) {
        return TRY_AGAIN;
}
if (res == -1) {
        return WAIT_ERROR;
}

\&.\&.\&.

SDL_SemPost(my_sem);\fR
.fi
.PP
.SH "SEE ALSO"
.PP
\fI\fBSDL_CreateSemaphore\fP\fR, \fI\fBSDL_DestroySemaphore\fP\fR, \fI\fBSDL_SemWait\fP\fR, \fI\fBSDL_SemTryWait\fP\fR, \fI\fBSDL_SemPost\fP\fR, \fI\fBSDL_SemValue\fP\fR
.\" created by instant / docbook-to-man, Tue 11 Sep 2001, 23:00