Mercurial > sdl-ios-xcode
annotate docs/man3/SDL_LockSurface.3 @ 896:b56dc586a5ef
Date: Tue, 16 Mar 2004 12:40:33 +0000
From: Alan Swanson
Subject: [SDL] [PATCH] Linux joystick evdev axis count fix
The event device configuration under Linux does not check the returned
ioctl value when reading the axis information. This means extra
undefined axes are returned.
Note, in EV_HandleEvents, the default for case EV_ABS is to return any
axis information which is fine as we have already checked for all valid
absolute axes. No new axes should be returned after opening the device.
(Unless, of course, the evdev allows closing and reassigning a new
device while in use and I can't believe that happens.)
| author | Sam Lantinga <slouken@libsdl.org> |
|---|---|
| date | Sun, 16 May 2004 22:48:06 +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 |