Mercurial > sdl-ios-xcode
annotate docs/man3/SDL_GL_GetProcAddress.3 @ 1626:a80e1e0880b8
Fixed bug #176
[I'm fixing this for the public headers, but I'm not going to bother for the SDL library code (yet)]
To clarify: Normaly, GCC (or, to be precise, the preprocessor) will ignore
this, and compile the code happily. However, one can specify -Wundef to get a
warning about this.
One can probably argue whether to consider this a bug or not; but I think that
(a) from a semantic point of view, using "#if FOO" when FOO is not defined is
strange, and (b) since it is possible to trigger a warning about this, and a
trivial fix exists, it should be corrected.
I can think of two alternative patches, BTW:
1) Simply use #define HAVE_FOO 0, instead of not defining HAVE_FOO at all
2) Change
#if HAVE_FOO
to
#if HAVE_FOO+0
which always does the right thing.
But I think I still prefer the attached patch :-).
author | Sam Lantinga <slouken@libsdl.org> |
---|---|
date | Thu, 13 Apr 2006 13:38:40 +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_GL_GetProcAddress" "3" "Tue 11 Sep 2001, 23:01" "SDL" "SDL API Reference" |
0 | 2 .SH "NAME" |
3 SDL_GL_GetProcAddress\- Get the address of a GL function | |
4 .SH "SYNOPSIS" | |
5 .PP | |
6 \fB#include "SDL\&.h" | |
7 .sp | |
8 \fBvoid *\fBSDL_GL_GetProcAddress\fP\fR(\fBconst char* proc\fR); | |
9 .SH "DESCRIPTION" | |
10 .PP | |
11 Returns the address of the GL function \fBproc\fR, or \fBNULL\fR if the function is not found\&. If the GL library is loaded at runtime, with \fI\fBSDL_GL_LoadLibrary\fP\fR, then \fIall\fP GL functions must be retrieved this way\&. Usually this is used to retrieve function pointers to OpenGL extensions\&. | |
12 .SH "EXAMPLE" | |
13 .PP | |
14 .nf | |
15 \f(CWtypedef void (*GL_ActiveTextureARB_Func)(unsigned int); | |
16 GL_ActiveTextureARB_Func glActiveTextureARB_ptr = 0; | |
17 int has_multitexture=1; | |
18 \&. | |
19 \&. | |
20 \&. | |
21 /* Get function pointer */ | |
22 glActiveTextureARB_ptr=(GL_ActiveTextureARB_Func) SDL_GL_GetProcAddress("glActiveTextureARB"); | |
23 | |
24 /* Check for a valid function ptr */ | |
25 if(!glActiveTextureARB_ptr){ | |
26 fprintf(stderr, "Multitexture Extensions not present\&. | |
27 "); | |
28 has_multitexture=0; | |
29 } | |
30 \&. | |
31 \&. | |
32 \&. | |
33 \&. | |
34 if(has_multitexture){ | |
35 glActiveTextureARB_ptr(GL_TEXTURE0_ARB); | |
36 \&. | |
37 \&. | |
38 } | |
39 else{ | |
40 \&. | |
41 \&. | |
42 }\fR | |
43 .fi | |
44 .PP | |
45 .SH "SEE ALSO" | |
46 .PP | |
47 \fI\fBSDL_GL_LoadLibrary\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 |