Mercurial > sdl-ios-xcode
view docs/man3/SDL_LockSurface.3 @ 4204:976bc19f8f6b SDL-1.2
1.2 Quartz video: Ripped out QuickDraw and QuickTime.
Now we use the software path for YUV, and CoreGraphics for 2D stuff.
There are several other 10.6 fixes in here, too...now we can build a 64-bit
SDL for Snow Leopard!
author | Ryan C. Gordon <icculus@icculus.org> |
---|---|
date | Mon, 21 Sep 2009 06:08:23 +0000 |
parents | 4e3b250c950e |
children | 1238da4a7112 |
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.TH "SDL_LockSurface" "3" "Tue 11 Sep 2001, 23:01" "SDL" "SDL API Reference" .SH "NAME" SDL_LockSurface \- Lock a surface for directly access\&. .SH "SYNOPSIS" .PP \fB#include "SDL\&.h" .sp \fBint \fBSDL_LockSurface\fP\fR(\fBSDL_Surface *surface\fR); .SH "DESCRIPTION" .PP \fBSDL_LockSurface\fP sets up a surface for directly accessing the pixels\&. Between calls to \fBSDL_LockSurface\fP and \fBSDL_UnlockSurface\fP, you can write to and read from \fBsurface->\fBpixels\fR\fR, using the pixel format stored in \fBsurface->\fBformat\fR\fR\&. Once you are done accessing the surface, you should use \fBSDL_UnlockSurface\fP to release it\&. .PP Not all surfaces require locking\&. If \fBSDL_MUSTLOCK\fP(\fBsurface\fR) evaluates to \fB0\fR, then you can read and write to the surface at any time, and the pixel format of the surface will not change\&. .PP No operating system or library calls should be made between lock/unlock pairs, as critical system locks may be held during this time\&. .PP It should be noted, that since SDL 1\&.1\&.8 surface locks are recursive\&. This means that you can lock a surface multiple times, but each lock must have a match unlock\&. .PP .nf \f(CW \&. \&. SDL_LockSurface( surface ); \&. /* Surface is locked */ /* Direct pixel access on surface here */ \&. SDL_LockSurface( surface ); \&. /* More direct pixel access on surface */ \&. SDL_UnlockSurface( surface ); /* Surface is still locked */ /* Note: Is versions < 1\&.1\&.8, the surface would have been */ /* no longer locked at this stage */ \&. SDL_UnlockSurface( surface ); /* Surface is now unlocked */ \&. \&.\fR .fi .PP .SH "RETURN VALUE" .PP \fBSDL_LockSurface\fP returns \fB0\fR, or \fB-1\fR if the surface couldn\&'t be locked\&. .SH "SEE ALSO" .PP \fI\fBSDL_UnlockSurface\fP\fR ...\" created by instant / docbook-to-man, Tue 11 Sep 2001, 23:01