Mercurial > sdl-ios-xcode
annotate docs/man3/SDL_LockSurface.3 @ 1795:398ac0f88e4d
Fixed bug #220
The AltiVec blitters don't compile, since they require __VEC__ to be enabled in
order for the compiler to understand "vector" and friends (i.e. do AltiVec)
But you don't want to turn AltiVec on globally, since then the code would only
run on a G4 (there are already runtime tests, before using the AltiVec
variants)
The solution here is to enable AltiVec locally, for the actual AltiVec code.
| author | Sam Lantinga <slouken@libsdl.org> |
|---|---|
| date | Tue, 09 May 2006 15:09:47 +0000 |
| parents | e5bc29de3f0a |
| children | 546f7c1eb755 |
| rev | line source |
|---|---|
|
181
e5bc29de3f0a
Updated from the SDL Documentation Project
Sam Lantinga <slouken@libsdl.org>
parents:
55
diff
changeset
|
1 .TH "SDL_LockSurface" "3" "Tue 11 Sep 2001, 23:01" "SDL" "SDL API Reference" |
| 0 | 2 .SH "NAME" |
| 3 SDL_LockSurface\- Lock a surface for directly access\&. | |
| 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 | |
|
181
e5bc29de3f0a
Updated from the SDL Documentation Project
Sam Lantinga <slouken@libsdl.org>
parents:
55
diff
changeset
|
48 ...\" created by instant / docbook-to-man, Tue 11 Sep 2001, 23:01 |