vrj::GlExtensionLoader Class Reference

Base class for OpenGL extension registration and lookup. More...

#include <GlExtensionLoader.h>

Inheritance diagram for vrj::GlExtensionLoader:

[legend]List of all members.

Public Types
typedef void(*)	VoidExtFunc (void)
	Void type to use when treating extensions the same.
Public Member Functions
	GlExtensionLoader ()
virtual	~GlExtensionLoader ()
virtual void	registerExtensions ()
	Register common extensions that we may need to use.
VoidExtFunc	getFunctionByName (const char *name)
	Return pointer to extension if it exists.

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Detailed Description

Base class for OpenGL extension registration and lookup.

This is a the base for a simple helper class for getting at OpenGL/WGL/GLX extensions that we need for VRJ.

Definition at line 43 of file GlExtensionLoader.h.

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Member Typedef Documentation

typedef void(*) vrj::GlExtensionLoader::VoidExtFunc(void)

Void type to use when treating extensions the same.

Definition at line 47 of file GlExtensionLoader.h.

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Constructor & Destructor Documentation

vrj::GlExtensionLoader::GlExtensionLoader

(

)

[inline]

Definition at line 50 of file GlExtensionLoader.h.

   {;}

virtual vrj::GlExtensionLoader::~GlExtensionLoader

(

)

[inline, virtual]

Definition at line 53 of file GlExtensionLoader.h.

   {;}

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Member Function Documentation

virtual void vrj::GlExtensionLoader::registerExtensions

(

)

[inline, virtual]

Register common extensions that we may need to use.

Reimplemented in vrj::GlExtensionLoaderWin32, and vrj::GlxExtensionLoader.

Definition at line 57 of file GlExtensionLoader.h.

Referenced by vrj::GlxExtensionLoader::registerExtensions(), and vrj::GlExtensionLoaderWin32::registerExtensions().

   {;}

GlExtensionLoader::VoidExtFunc vrj::GlExtensionLoader::getFunctionByName

(

const char *

name

)

Return pointer to extension if it exists.

Definition at line 53 of file GlExtensionLoader.cpp.

Referenced by vrj::GlxExtensionLoader::registerExtensions(), and vrj::GlExtensionLoaderWin32::registerExtensions().

{
   VoidExtFunc found_func(NULL);

#if defined(VPR_OS_Darwin)
   if (NSIsSymbolNameDefined(name))
   {
      NSSymbol symbol = NSLookupAndBindSymbol(name);
      if (0 != symbol)
      {
         found_func = VoidExtFunc(NSAddressOfSymbol(symbol)); 
      }
   }
#elif defined(WIN32)

   found_func = (void(__cdecl*)(void)) wglGetProcAddress(name);

#elif defined(VPR_OS_IRIX) || defined(VPR_OS_HPUX) || \
   defined(VPR_OS_Linux) || defined(VPR_OS_FreeBSD) || defined(VPR_OS_Solaris)

   /* Workaround for multiple nVidia/Linux installation bugs, based on code in OpenSG */      
   static void (*(*__GetProcAddress)(const GLubyte *))(void) = NULL; 

   static void* lib_handle(NULL); 

   if (lib_handle == NULL)
   {
      lib_handle = dlopen(NULL, RTLD_NOW | RTLD_LOCAL); 

      if (!lib_handle)
      {
         vprDEBUG(vprDBG_ALL, vprDBG_WARNING_LVL) << "Error in dlopen:" << dlerror() << vprDEBUG_FLUSH;         
      }
   }

   if (__GetProcAddress == NULL)
   {
      __GetProcAddress = (void (*(*)(const GLubyte*))()) dlsym(lib_handle, "glXGetProcAddressARB"); 

      if (__GetProcAddress == NULL)
      {
         __GetProcAddress = (void (*(*)(const GLubyte*))()) dlsym(lib_handle, "glXGetProcAddress"); 

         if (__GetProcAddress == NULL)
         {
            vprDEBUG(vprDBG_ALL, vprDBG_WARNING_LVL) << "WARNING: Neither glXGetProcAddress nor "
                     "glXGetProcAddressARB found! Disabling all "
                     " extensions lookups.\n" << vprDEBUG_FLUSH;                   
         }
         else
         {
            vprDEBUG(vprDBG_ALL, vprDBG_STATE_LVL) << "Using glXGetProcAddress for GL extension handling.\n" << vprDEBUG_FLUSH;
         }
      }
      else
      {
         vprDEBUG(vprDBG_ALL, vprDBG_STATE_LVL) << "Using glXGetProcAddressARB for GL extension handling.\n" << vprDEBUG_FLUSH;
      }
   }

   if (__GetProcAddress != NULL)
   {
      found_func = reinterpret_cast<VoidExtFunc>(__GetProcAddress((const GLubyte*)name)); 
   }
   else
   {
      found_func = (VoidExtFunc)(dlsym(lib_handle, name)); 
   } 

#else
   vprDEBUG(vprDBG_ALL, vprDBG_WARNING_LVL) 
      << "Warnining: Missing implementation for extension registration on this platform.\n"
      << "OpenGL extensions will not be available to VR Juggler.\n" << vprDEBUG_FLUSH;
#endif

   if (found_func == NULL)
   {
      vprDEBUG(vprDBG_ALL, vprDBG_HVERB_LVL) << "GlExtensionLoader:: Couldn't find function " << name << std::endl << vprDEBUG_FLUSH;          
   }
   else
   {
      vprDEBUG(vprDBG_ALL, vprDBG_HVERB_LVL) << "GlExtensionLoader:: Found function " << name << std::endl << vprDEBUG_FLUSH;          
   }

   return found_func;
}

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The documentation for this class was generated from the following files:

• GlExtensionLoader.h
• GlExtensionLoader.cpp

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