HGrid.h

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// This file is part of the MercuryDPM project (https://www.mercurydpm.org).
// Copyright (c), The MercuryDPM Developers Team. All rights reserved.
// License: BSD 3-Clause License; see the LICENSE file in the root directory.
 
#ifndef HGRID_H
#define HGRID_H
 
#include <vector>
#include "Math/ExtendedMath.h"
#include "Particles/HGridCell.h"
 
class BaseParticle;
 
class HGrid
{
public:
    HGrid();
    
    HGrid(unsigned int num_buckets, double cellOverSizeRatio, std::vector<double>& cellSizes);
    
    ~HGrid();
    
    void insertParticleToHgrid(BaseParticle* obj);
    
    inline unsigned int computeHashBucketIndex(int x, int y, int z, unsigned int l) const
    {
        static const unsigned int h1 = 0x8da6b343u; // Large multiplicative constants;
        static const unsigned int h2 = 0xd8163841u; // here arbitrarily chosen primes
        static const unsigned int h3 = 0xcb1ab31fu;
        static const unsigned int h4 = 0x165667b1u;
        
        return (h1 * x + h2 * y + h3 * z + h4 * l) % numberOfBuckets_;
    }
    
    inline unsigned int computeHashBucketIndex(HGridCell hGridCell) const
    {
        return computeHashBucketIndex(hGridCell.getHGridX(),
                                      hGridCell.getHGridY(),
                                      hGridCell.getHGridZ(),
                                      hGridCell.getHGridLevel());
    }
    
    unsigned int computeHashBucketIndex(int x, int y, unsigned int l) const;
    
    void clearBucketIsChecked();
    
    void clearFirstBaseParticleInBucket();
    
    void setFirstBaseParticleInBucket(unsigned int i, BaseParticle* p)
    { firstBaseParticleInBucket_[i] = p; }
    
    void setBucketIsChecked(unsigned int i)
    { bucketIsChecked_[i] = true; }
    
    bool getBucketIsChecked(unsigned int i) const
    { return bucketIsChecked_[i]; }
    
    Mdouble getCellOverSizeRatio() const
    { return cellOverSizeRatio_; }
    
    double getCellSize(unsigned int i) const
    { return cellSizes_[i]; }
    
    const std::vector<double>& getCellSizes() const
    { return cellSizes_; }
    
    const BaseParticle* getFirstBaseParticleInBucket(unsigned int i) const
    { return firstBaseParticleInBucket_[i]; }
    
    BaseParticle* getFirstBaseParticleInBucket(unsigned int i)
    { return firstBaseParticleInBucket_[i]; }
    
    double getInvCellSize(unsigned int i) const
    {
        logger.assert_debug(i<invCellSizes_.size(),"Error in getInvCellSize %<%", i, invCellSizes_.size());
        return invCellSizes_[i];
    }
    
    const std::vector<double>& getInvCellSizes() const
    { return invCellSizes_; }
    
    bool getNeedsRebuilding() const
    { return needsRebuilding_; }
    
    unsigned int getNumberOfBuckets() const
    { return numberOfBuckets_; }
    
    unsigned long getNumberOfLevels() const
    { return cellSizes_.size(); }
    
    int getOccupiedLevelsMask() const
    { return occupiedLevelsMask_; }
    
    void info() const;
 
private:
    bool needsRebuilding_;
    
    unsigned int numberOfBuckets_;
    
    Mdouble cellOverSizeRatio_;
    
    int occupiedLevelsMask_;
    
    std::vector<double> cellSizes_;
    
    std::vector<double> invCellSizes_;
    
    std::vector<BaseParticle*> firstBaseParticleInBucket_;
    
    std::vector<bool> bucketIsChecked_;
};
 
#endif