text: /***************************************************************************
   * Copyright 1998-2017 by authors (see AUTHORS.txt)                        *
   *                                                                         *
   *   This file is part of LuxRender.                                       *
   *                                                                         *
   * Licensed under the Apache License, Version 2.0 (the "License");         *
   * you may not use this file except in compliance with the License.        *
   * You may obtain a copy of the License at                                 *
   *                                                                         *
   *     http://www.apache.org/licenses/LICENSE-2.0                          *
   *                                                                         *
   * Unless required by applicable law or agreed to in writing, software     *
   * distributed under the License is distributed on an "AS IS" BASIS,       *
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.*
   * See the License for the specific language governing permissions and     *
   * limitations under the License.                                          *
   ***************************************************************************/
  
  #ifndef _SLG_BIDIRVMCPU_H
  #define	_SLG_BIDIRVMCPU_H
  
  #include "slg/slg.h"
  #include "slg/engines/bidircpu/bidircpu.h"
  
  namespace slg {
  
  //------------------------------------------------------------------------------
  // Bidirectional path tracing with Vertex Merging CPU render engine
  //------------------------------------------------------------------------------
  
  class BiDirVMCPURenderEngine;
  class BiDirVMCPURenderThread;
  
  class HashGrid {
  public:
  	HashGrid() { }
  	~HashGrid() { }
  
  	u_int GetVertexCount() const { return vertexCount; }
  
  	void Build(vector<vector<PathVertexVM> > &pathsVertices, const float radius);
  
  	void Process(const BiDirVMCPURenderThread *thread,
  		const PathVertexVM &eyeVertex, luxrays::Spectrum *radiance) const;
  
  	//void PrintStatistics() const;
  
  private:
  	void Process(const BiDirVMCPURenderThread *thread,
  		const PathVertexVM &eyeVertex, const int i0, const int i1,
  		luxrays::Spectrum *radiance) const;
  	void Process(const BiDirVMCPURenderThread *thread,
  		const PathVertexVM &eyeVertex, const PathVertexVM *lightVertex,
  		luxrays::Spectrum *radiance) const;
  
  	void HashRange(const u_int i, int *i0, int *i1) const {
  		if (i == 0) {
  			*i0 = 0;
  			*i1 = cellEnds[0];
  		} else {
  			*i0 = cellEnds[i - 1];
  			*i1 = cellEnds[i];
  		}
  	}
  
  	u_int Hash(const int ix, const int iy, const int iz) const {
  		return (u_int)((ix * 73856093) ^ (iy * 19349663) ^ (iz * 83492791)) % gridSize;
  	}
  
  	u_int Hash(const luxrays::Point &p) const {
  		const luxrays::Vector distMin = p - vertexBBox.pMin;
  
  		return Hash(
  				luxrays::Float2Int(invCellSize * distMin.x),
  				luxrays::Float2Int(invCellSize * distMin.y),
  				luxrays::Float2Int(invCellSize * distMin.z));
      }
  
  	float radius2;
  	u_int gridSize;
  	float invCellSize;
  	luxrays::BBox vertexBBox;
  	u_int vertexCount;
  
  	vector<const PathVertexVM *> lightVertices;
      vector<int> cellEnds;
  
  	// Statistics
  	//mutable u_int mergeHitsV2V; // merge Volume with Volume path vertex
  	//mutable u_int mergeHitsV2S; // merge Volume with Surface path vertex
  	//mutable u_int mergeHitsS2S; // merge Surface with Surface path vertex
  };
  
  class BiDirVMCPURenderThread : public BiDirCPURenderThread {
  public:
  	BiDirVMCPURenderThread(BiDirVMCPURenderEngine *engine, const u_int index,
  			luxrays::IntersectionDevice *device);
  
  	friend class HashGrid;
  	friend class BiDirVMCPURenderEngine;
  
  private:
  	virtual boost::thread *AllocRenderThread() { return new boost::thread(&BiDirVMCPURenderThread::RenderFuncVM, this); }
  
  	void RenderFuncVM();
  };
  
  class BiDirVMCPURenderEngine : public BiDirCPURenderEngine {
  public:
  	BiDirVMCPURenderEngine(const RenderConfig *cfg, Film *flm, boost::mutex *flmMutex);
  
  	virtual RenderEngineType GetType() const { return GetObjectType(); }
  	virtual std::string GetTag() const { return GetObjectTag(); }
  
  	//--------------------------------------------------------------------------
  	// Static methods used by RenderEngineRegistry
  	//--------------------------------------------------------------------------
  
  	static RenderEngineType GetObjectType() { return BIDIRVMCPU; }
  	static std::string GetObjectTag() { return "BIDIRVMCPU"; }
  	static luxrays::Properties ToProperties(const luxrays::Properties &cfg);
  	static RenderEngine *FromProperties(const RenderConfig *rcfg, Film *flm, boost::mutex *flmMutex);
  
  	friend class BiDirVMCPURenderThread;
  
  protected:
  	static const luxrays::Properties &GetDefaultProps();
  
  	virtual void StartLockLess();
  
  private:
  	CPURenderThread *NewRenderThread(const u_int index, luxrays::IntersectionDevice *device) {
  		return new BiDirVMCPURenderThread(this, index, device);
  	}
  };
  
  }
  
  #endif	/* _SLG_BIDIRVMCPU_H */
  