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Diffstat (limited to 'distrib/sdl-1.2.15/docs/man3/SDL_LockSurface.3')
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diff --git a/distrib/sdl-1.2.15/docs/man3/SDL_LockSurface.3 b/distrib/sdl-1.2.15/docs/man3/SDL_LockSurface.3 new file mode 100644 index 0000000..6db3ad7 --- /dev/null +++ b/distrib/sdl-1.2.15/docs/man3/SDL_LockSurface.3 @@ -0,0 +1,48 @@ +.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 |