75 lines
2.4 KiB
Plaintext
75 lines
2.4 KiB
Plaintext
//C++ header - Open Scene Graph - Copyright (C) 1998-2002 Robert Osfield
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//Distributed under the terms of the GNU Library General Public License (LGPL)
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//as published by the Free Software Foundation.
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#ifndef OSG_GLEXTENSIONS
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#define OSG_GLEXTENSIONS 1
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#include <osg/Export>
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#if defined(WIN32)
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#include <windows.h>
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#elif defined(__DARWIN_OSX__)
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#include <string>
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#include <mach-o/dyld.h>
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#else
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#include <dlfcn.h>
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#endif
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namespace osg {
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/** return true if OpenGL "extension" is supported.
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* note: Must only called within a valid OpenGL context,
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* undefined behavior may occur otherwise.
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*/
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SG_EXPORT extern const bool isGLExtensionSupported(const char *extension);
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/** return the address of the specified OpenGL function.
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* return NULL if function not supported by OpenGL library.
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* Note, glGLExtensionFuncPtr is declared inline so that the code
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* is compiled localy to the calling code. This should get by Windows
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* dumb implementation of having different GL function ptr's for each
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* library when links to it.
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*/
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inline void* getGLExtensionFuncPtr(const char *funcName)
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{
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#if defined(WIN32)
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return wglGetProcAddress(funcName);
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#elif defined(__DARWIN_OSX__)
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std::string temp( "_" );
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temp += funcName; // Mac OS X prepends an underscore on function names
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if ( NSIsSymbolNameDefined( temp.c_str() ) )
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{
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NSSymbol symbol = NSLookupAndBindSymbol( temp.c_str() );
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return NSAddressOfSymbol( symbol );
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} else
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return NULL;
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#else // all other unixes
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// Note: although we use shl_load() etc. for Plugins on HP-UX, it's
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// not neccessary here since we only used them because library
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// intialization was not taking place with dlopen() which renders
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// Plugins useless on HP-UX.
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static void *lib = dlopen("libGL.so", RTLD_LAZY);
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if (lib)
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return dlsym(lib, funcName);
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else
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return NULL;
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#endif
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}
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/** return the address of the specified OpenGL function, if not found then
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* check a second function name, if this fails then return NULL as function is
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* not supported by OpenGL library. This is usual for checking something
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* like glActiveTexture (which is in OGL1.3) or glActiveTextureARB.
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*/
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inline void* getGLExtensionFuncPtr(const char *funcName,const char *fallbackFuncName)
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{
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void* ptr = getGLExtensionFuncPtr(funcName);
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if (ptr) return ptr;
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return getGLExtensionFuncPtr(fallbackFuncName);
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}
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}
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#endif
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