text: //
  // Copyright 2016 Pixar
  //
  // Licensed under the Apache License, Version 2.0 (the "Apache License")
  // with the following modification; you may not use this file except in
  // compliance with the Apache License and the following modification to it:
  // Section 6. Trademarks. is deleted and replaced with:
  //
  // 6. Trademarks. This License does not grant permission to use the trade
  //    names, trademarks, service marks, or product names of the Licensor
  //    and its affiliates, except as required to comply with Section 4(c) of
  //    the License and to reproduce the content of the NOTICE file.
  //
  // You may obtain a copy of the Apache License at
  //
  //     http://www.apache.org/licenses/LICENSE-2.0
  //
  // Unless required by applicable law or agreed to in writing, software
  // distributed under the Apache License with the above modification is
  // distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
  // KIND, either express or implied. See the Apache License for the specific
  // language governing permissions and limitations under the Apache License.
  //
  #ifndef VMP_USD_USDVMP_H
  #define VMP_USD_USDVMP_H
  
  // Glew must be included before gl.h
  #include "pxr/imaging/glf/glew.h"
  
  #include <iostream>
  #include <GL/gl.h>
  #include <GL/glu.h>
  
  #include <boost/shared_ptr.hpp>
  
  #include "pxr/base/tf/diagnostic.h"
  #include "pxr/base/tf/hash.h"
  #include "pxr/base/tf/stringUtils.h"
  #include "pxr/base/tf/stopwatch.h"
  #include "pxr/usd/usd/prim.h"
  #include "pxr/usd/usd/stage.h"
  #include "pxr/usdImaging/usdImaging/gl.h"
  
  #include "katanaPluginApi/FnViewerModifier.h"
  #include <FnAttribute/FnGroupBuilder.h>
  #include <FnAttribute/FnAttribute.h>
  #include "katanaPluginApi/FnViewerModifierInput.h"
  #include <FnLogging/FnLogging.h>
  
  #include "debugCodes.h"
  
  FnLogSetup("USDVMP")
  
  namespace FnKat = Foundry::Katana;
  
  
  typedef boost::shared_ptr<UsdImagingGL> UsdImagingGLSharedPtr;
  
  //--------------------------------------------------------------------------------
  // USDVMP
  //--------------------------------------------------------------------------------
  
  class USDVMP : public FnKat::ViewerModifier
  {
  public:
      USDVMP(FnKat::GroupAttribute args);
  
      virtual ~USDVMP();
  
      static FnKat::ViewerModifier* create(FnKat::GroupAttribute args);
  
      static FnKat::GroupAttribute getArgumentTemplate();
  
      static const char* getLocationType();
  
      virtual void deepSetup(FnKat::ViewerModifierInput& input);
  
      virtual void setup(FnKat::ViewerModifierInput& input);
  
      virtual void draw(FnKat::ViewerModifierInput& input);
  
      virtual void cleanup(FnKat::ViewerModifierInput& input);
  
      virtual void deepCleanup(FnKat::ViewerModifierInput& input);
  
      static void onFrameBegin() {}
      
      static void onFrameEnd() {}
      
      // DEPRECATED: getLocalSpaceBoundingBox is preferred
      virtual FnKat::DoubleAttribute getWorldSpaceBoundingBox(
          FnKat::ViewerModifierInput& input);
  
      static void flush();
  
  private:
      void _loadSubtreeForCurrentPrim();
  
      UsdStageRefPtr _stage;
      UsdImagingGLSharedPtr _renderer;
      UsdImagingGL::RenderParams _params;
      UsdPrim _prim;
  };
  
  #endif 
  