imstkSpatialHashTableSeparateChaining.h

/*
** This file is part of the Interactive Medical Simulation Toolkit (iMSTK)
** iMSTK is distributed under the Apache License, Version 2.0.
** See accompanying NOTICE for details.
*/

#pragma once

#include "imstkSpatialHashTable.h"
#include "imstkMath.h"
#include "imstkVecDataArray.h"

#include <unordered_set>

namespace imstk
{
struct PointEntry
{
    Vec3d point;
    unsigned long ID;
    double* cellSize;
};
} // namespace imstk

namespace std
{
template<> struct hash<imstk::PointEntry>
{
    size_t operator()(const imstk::PointEntry& point) const
    {
        unsigned int x = (unsigned int)(point.point.x() / point.cellSize[0]);
        unsigned int y = (unsigned int)(point.point.y() / point.cellSize[1]);
        unsigned int z = (unsigned int)(point.point.z() / point.cellSize[2]);

        return (104729 * x + 104743 * y + 104759 * z);
    }
};

template<> struct equal_to<imstk::PointEntry>
{
    size_t operator()(const imstk::PointEntry& point1, const imstk::PointEntry& point2) const
    {
        if (point1.ID != point2.ID)
        {
            return false;
        }

        if (point1.point != point2.point)
        {
            return false;
        }

        return true;
    }
};
} // namespace std

namespace imstk
{
class SpatialHashTableSeparateChaining : public SpatialHashTable
{
public:
    SpatialHashTableSeparateChaining();

    void insertPoints(const VecDataArray<double, 3>& points);

    void insertPoint(const Vec3d& point);

    void setLoadFactorMax(float loadFactorMax);

    std::vector<size_t> getPointsInAABB(const Vec3d& corner1, const Vec3d& corner2);

    void getPointsInAABB(std::vector<size_t>& result, const Vec3d& corner1, const Vec3d& corner2);

    std::vector<size_t> getPointsInSphere(const Vec3d& ppos, double radius);

    void getPointsInSphere(std::vector<size_t>& result, const Vec3d& ppos, const double radius);

    void clear();

    virtual void setCellSize(double x, double y, double z) override;

    void recomputePointHash();

protected:
    virtual void rehash() override;

    float m_loadFactorMax     = 10.0f;
    unsigned long m_currentID = 0;
    std::shared_ptr<std::unordered_set<PointEntry>> m_table;
};
} // namespace imstk