OpenSceneGraph/include/osg/GLExtensions

84 lines
2.7 KiB
C++

/* -*-c++-*- OpenSceneGraph - Copyright (C) 1998-2003 Robert Osfield
*
* This library is open source and may be redistributed and/or modified under
* the terms of the OpenSceneGraph Public License (OSGPL) version 0.0 or
* (at your option) any later version. The full license is in LICENSE file
* included with this distribution, and on the openscenegraph.org website.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* OpenSceneGraph Public License for more details.
*/
#ifndef OSG_GLEXTENSIONS
#define OSG_GLEXTENSIONS 1
#include <osg/Export>
#if defined(WIN32)
#define WIN32_LEAN_AND_MEAN
#include <windows.h>
#elif defined(__DARWIN_OSX__)
#include <string>
#include <mach-o/dyld.h>
#else
#include <dlfcn.h>
#endif
namespace osg {
/** return true if OpenGL "extension" is supported.
* note: Must only called within a valid OpenGL context,
* undefined behavior may occur otherwise.
*/
extern SG_EXPORT bool isGLExtensionSupported(const char *extension);
/** return the address of the specified OpenGL function.
* return NULL if function not supported by OpenGL library.
* Note, glGLExtensionFuncPtr is declared inline so that the code
* is compiled localy to the calling code. This should get by Windows
* dumb implementation of having different GL function ptr's for each
* library when links to it.
*/
inline void* getGLExtensionFuncPtr(const char *funcName)
{
#if defined(WIN32)
return (void*)wglGetProcAddress(funcName);
#elif defined(__DARWIN_OSX__)
std::string temp( "_" );
temp += funcName; // Mac OS X prepends an underscore on function names
if ( NSIsSymbolNameDefined( temp.c_str() ) )
{
NSSymbol symbol = NSLookupAndBindSymbol( temp.c_str() );
return NSAddressOfSymbol( symbol );
} else
return NULL;
#else // all other unixes
return dlsym(0, funcName);
#endif
}
/** return the address of the specified OpenGL function, if not found then
* check a second function name, if this fails then return NULL as function is
* not supported by OpenGL library. This is usual for checking something
* like glActiveTexture (which is in OGL1.3) or glActiveTextureARB.
*/
inline void* getGLExtensionFuncPtr(const char *funcName,const char *fallbackFuncName)
{
void* ptr = getGLExtensionFuncPtr(funcName);
if (ptr) return ptr;
return getGLExtensionFuncPtr(fallbackFuncName);
}
/** return true if OpenGL "extension" is supported.
* note: Must only called within a valid OpenGL context,
* undefined behavior may occur otherwise.
*/
extern SG_EXPORT bool isGLUExtensionSupported(const char *extension);
}
#endif