Mercurial > sdl-ios-xcode
annotate docs/man3/SDL_LockSurface.3 @ 1754:c67921b517c3
Date: Sun, 30 Apr 2006 14:20:05 +1000
From: Rob
Subject: [SDL] SDL pre-release
OpenGL fails on the zipped pre-release source accessible from
http://www.libsdl.org/svn.php.
Appears to be following lines in sdl_wing.c (lines 341-345):
wglext = (const char *)this->glGetString(GL_EXTENSIONS);
if ( !SDL_strstr(wglext, "WGL_EXT_swap_control") ) {
this->gl_data->wglSwapIntervalEXT = NULL;
this->gl_data->wglGetSwapIntervalEXT = NULL;
}
glGetString is a null pointer, as are other gl function pointers, so call
fails. Never looked at sdl source before, so no further than that as yet.
| author | Sam Lantinga <slouken@libsdl.org> |
|---|---|
| date | Mon, 01 May 2006 07:15:35 +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 |