Mercurial > sdl-ios-xcode
view docs/man3/SDL_SemWait.3 @ 816:428f688f2ad2
Date: Fri, 13 Feb 2004 17:03:16 +0100
From: Max Horn
Subject: Modifier key fix
The internal modifier state can get out of sync with reality. To
trigger this, do for example this:
1) Launch an SDL app
2) Alt-click on the desktop (this will hide the SDL app).
3) Bring the SDL app back to the front
4) SDL will still think alt is pressed (and as such will treat left
clicks like middle clicks). If you press and release alt, it'll be fine
again.
The attached patch cures this by rechecking the modifier state whenever
we process an event.
| author | Sam Lantinga <slouken@libsdl.org> |
|---|---|
| date | Fri, 13 Feb 2004 17:57:16 +0000 |
| parents | e5bc29de3f0a |
| children | 546f7c1eb755 |
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.TH "SDL_SemWait" "3" "Tue 11 Sep 2001, 23:00" "SDL" "SDL API Reference" .SH "NAME" SDL_SemWait\- Lock a semaphore and suspend the thread if the semaphore value is zero\&. .SH "SYNOPSIS" .PP \fB#include "SDL\&.h" #include "SDL_thread\&.h" .sp \fBint \fBSDL_SemWait\fP\fR(\fBSDL_sem *sem\fR); .SH "DESCRIPTION" .PP \fBSDL_SemWait()\fP suspends the calling thread until either the semaphore pointed to by \fBsem\fR has a positive value, the call is interrupted by a signal or error\&. If the call is successful it will atomically decrement the semaphore value\&. .PP After \fBSDL_SemWait()\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 successful or \fB-1\fR if there was an error (leaving the semaphore unchanged)\&. .SH "EXAMPLES" .PP .PP .nf \f(CWif (SDL_SemWait(my_sem) == -1) { return WAIT_FAILED; } \&.\&.\&. SDL_SemPost(my_sem);\fR .fi .PP .SH "SEE ALSO" .PP \fI\fBSDL_CreateSemaphore\fP\fR, \fI\fBSDL_DestroySemaphore\fP\fR, \fI\fBSDL_SemTryWait\fP\fR, \fI\fBSDL_SemWaitTimeout\fP\fR, \fI\fBSDL_SemPost\fP\fR, \fI\fBSDL_SemValue\fP\fR ...\" created by instant / docbook-to-man, Tue 11 Sep 2001, 23:00