Mercurial > sdl-ios-xcode
view 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 |
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.TH "SDL_GL_GetProcAddress" "3" "Tue 11 Sep 2001, 23:01" "SDL" "SDL API Reference" .SH "NAME" SDL_GL_GetProcAddress\- Get the address of a GL function .SH "SYNOPSIS" .PP \fB#include "SDL\&.h" .sp \fBvoid *\fBSDL_GL_GetProcAddress\fP\fR(\fBconst char* proc\fR); .SH "DESCRIPTION" .PP 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\&. .SH "EXAMPLE" .PP .nf \f(CWtypedef void (*GL_ActiveTextureARB_Func)(unsigned int); GL_ActiveTextureARB_Func glActiveTextureARB_ptr = 0; int has_multitexture=1; \&. \&. \&. /* Get function pointer */ glActiveTextureARB_ptr=(GL_ActiveTextureARB_Func) SDL_GL_GetProcAddress("glActiveTextureARB"); /* Check for a valid function ptr */ if(!glActiveTextureARB_ptr){ fprintf(stderr, "Multitexture Extensions not present\&. "); has_multitexture=0; } \&. \&. \&. \&. if(has_multitexture){ glActiveTextureARB_ptr(GL_TEXTURE0_ARB); \&. \&. } else{ \&. \&. }\fR .fi .PP .SH "SEE ALSO" .PP \fI\fBSDL_GL_LoadLibrary\fP\fR ...\" created by instant / docbook-to-man, Tue 11 Sep 2001, 23:01