Mercurial > sdl-ios-xcode
view docs/man3/SDL_LockSurface.3 @ 1258:b2283b0ded26
Date: Thu, 19 Jan 2006 20:02:29 +0200
From: Vassilis Virvilis <vasvir@iit.demokritos.gr>
Subject: [SDL] Request: Please reconsider adding tag in SDL_Event
Hi,
Patch in question:
--- include/SDL_events.h 20 Aug 2004 18:57:01 -0000 1.11
+++ include/SDL_events.h 19 Jan 2006 17:35:09 -0000
@@ -214,7 +214,7 @@
} SDL_SysWMEvent;
/* General event structure */
-typedef union {
+typedef union SDL_Event {
Uint8 type;
SDL_ActiveEvent active;
SDL_KeyboardEvent key;
Reasoning:
----------
1) Allows forward declaration of the SDL_Event union in C++. Please
note that in plain C it is possible to forward declare it.
2) Forward declaration is good because it allows encapsulation. It hides
the specific implementation and does not necessarily exposes SDL staff
to my appication's namespace
3) It can't harm plain C because tags are living in a different namespace
than typenames
4) It is already done like this in other places in SDL. Check for example
SDL_KeySym, and SDL_.*Event structures.
5) Right now I have to include SDL/event.h from a C++ header file. See 2)
author | Sam Lantinga <slouken@libsdl.org> |
---|---|
date | Fri, 20 Jan 2006 13:07:25 +0000 (2006-01-20) |
parents | e5bc29de3f0a |
children | 546f7c1eb755 |
line wrap: on
line source
.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