Mercurial > sdl-ios-xcode
annotate docs/man3/SDL_LockSurface.3 @ 2318:0c653886cce7
HandleEvent() returns done each time it is called. If done was set to 0 the program should quit, but because done is not checked until *all* events are handled a
following event can reset done to 1 and prevent the program from terminating when told to. I fixed the while loop that handles events to check for the state of done
after handling each event. That could leave some events unhandled when the program exits, but it ensures that the program will exit.
| author | Bob Pendleton <bob@pendleton.com> |
|---|---|
| date | Wed, 20 Feb 2008 23:27:33 +0000 |
| parents | 546f7c1eb755 |
| children | 1238da4a7112 |
| rev | line source |
|---|---|
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Updated from the SDL Documentation Project
Sam Lantinga <slouken@libsdl.org>
parents:
55
diff
changeset
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1 .TH "SDL_LockSurface" "3" "Tue 11 Sep 2001, 23:01" "SDL" "SDL API Reference" |
| 0 | 2 .SH "NAME" |
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2283
546f7c1eb755
Merged revision 3472 from SDL 1.2, fixing bug #493
Sam Lantinga <slouken@libsdl.org>
parents:
181
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3 SDL_LockSurface \- Lock a surface for directly access\&. |
| 0 | 4 .SH "SYNOPSIS" |
| 5 .PP | |
| 6 \fB#include "SDL\&.h" | |
| 7 .sp | |
| 8 \fBint \fBSDL_LockSurface\fP\fR(\fBSDL_Surface *surface\fR); | |
| 9 .SH "DESCRIPTION" | |
| 10 .PP | |
| 11 \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\&. | |
| 12 .PP | |
| 13 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\&. | |
| 14 .PP | |
| 15 No operating system or library calls should be made between lock/unlock pairs, as critical system locks may be held during this time\&. | |
| 16 .PP | |
| 17 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\&. | |
| 18 .PP | |
| 19 .nf | |
| 20 \f(CW \&. | |
| 21 \&. | |
| 22 SDL_LockSurface( surface ); | |
| 23 \&. | |
| 24 /* Surface is locked */ | |
| 25 /* Direct pixel access on surface here */ | |
| 26 \&. | |
| 27 SDL_LockSurface( surface ); | |
| 28 \&. | |
| 29 /* More direct pixel access on surface */ | |
| 30 \&. | |
| 31 SDL_UnlockSurface( surface ); | |
| 32 /* Surface is still locked */ | |
| 33 /* Note: Is versions < 1\&.1\&.8, the surface would have been */ | |
| 34 /* no longer locked at this stage */ | |
| 35 \&. | |
| 36 SDL_UnlockSurface( surface ); | |
| 37 /* Surface is now unlocked */ | |
| 38 \&. | |
| 39 \&.\fR | |
| 40 .fi | |
| 41 .PP | |
| 42 .SH "RETURN VALUE" | |
| 43 .PP | |
| 44 \fBSDL_LockSurface\fP returns \fB0\fR, or \fB-1\fR if the surface couldn\&'t be locked\&. | |
| 45 .SH "SEE ALSO" | |
| 46 .PP | |
| 47 \fI\fBSDL_UnlockSurface\fP\fR | |
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181
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Updated from the SDL Documentation Project
Sam Lantinga <slouken@libsdl.org>
parents:
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diff
changeset
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48 ...\" created by instant / docbook-to-man, Tue 11 Sep 2001, 23:01 |