BvhAccelerator.h

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/*
 * Copyright (C) <2012> <EDF-R&D> <FRANCE>
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 * This program 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 GNU General Public License for more details.
 * You should have received a copy of the GNU General Public License along
 * with this program; if not, write to the Free Software Foundation, Inc.,
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 */
 
#ifndef BVHACCELERATOR_H
#define BVHACCELERATOR_H
 
#include "Geometry/BBox.h"
#include <vector>
#include "Geometry/Shape.h"
#include "Accelerator.h"
 
struct BVHBuildNode;
 
// BVHAccel Forward Declarations
struct BVHPrimitiveInfo;
struct LinearBVHNode;
 
class BvhAccelerator : public Accelerator
{
 
public:
    BvhAccelerator(std::vector<Shape*>* _initialMesh = NULL, BBox _globalBox = BBox(),
                   unsigned int maxProf = 8, const string& sm = "sah");
    virtual ~BvhAccelerator()
    {
        free(nodes);
    }
 
    virtual bool build();
 
    virtual decimal traverse(Ray* r, std::list<Intersection>& result) const;
 
    void setMaxProfondeur(int _maxProfondeur)
    {
        maxProfondeur = _maxProfondeur;
    }
    int getMaxProfondeur()
    {
        return maxProfondeur;
    }
    void setMaxPrimPerLeaf(int _maxPrimPerLeaf)
    {
        maxPrimPerLeaf = _maxPrimPerLeaf;
    }
    int getMaxPrimPerLeaf()
    {
        return maxPrimPerLeaf;
    }
    std::vector<BBox>& getBBox()
    {
        return tableBox;
    }
 
    void print();
    /* Uncommented cause not used:
        bool alreadyFail;
        unsigned int nbFail;
        Ray r;
        bool trace;
    */
protected:
    // BVHAccel Private Methods
    BVHBuildNode* recursiveBuild(std::vector<BVHPrimitiveInfo>& buildData, unsigned int start,
                                 unsigned int end, unsigned int* totalNodes,
                                 std::vector<Shape*>& orderedPrims);
    unsigned int flattenBVHTree(BVHBuildNode* node, unsigned int* offset);
 
    // BVHAccel Private Data
    unsigned int maxPrimsInNode; 
    enum SplitMethod
    {
        SPLIT_MIDDLE,
        SPLIT_EQUAL_COUNTS,
        SPLIT_SAH
    };
    SplitMethod splitMethod; 
    LinearBVHNode* nodes;    
 
    std::vector<Shape*>
        primitives; 
    BBox globalBox; 
 
    std::vector<BBox> tableBox; 
 
    int maxProfondeur;  
    int maxPrimPerLeaf; 
 
    int realMaxProfondeur; 
    /* Uncommented cause not used:
        float isectCost;
        float emptyBonus;
        float traversalCost; */
};
 
#endif