GridSectorizer.h

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#ifndef _GRID_SECTORIZER_H
#define _GRID_SECTORIZER_H

//#define _USE_ORDERED_LIST

#include "RakMemoryOverride.h"

#ifdef _USE_ORDERED_LIST
#include "DS_OrderedList.h"
#else
#include "DS_List.h"
#endif

class GridSectorizer
{
public:
    GridSectorizer();
    ~GridSectorizer();

    // _cellWidth, _cellHeight is the width and height of each cell in world units
    // minX, minY, maxX, maxY are the world dimensions (can be changed to dynamically allocate later if needed)
    void Init(const float _maxCellWidth, const float _maxCellHeight, const float minX, const float minY, const float maxX, const float maxY);

    // Adds a pointer to the grid with bounding rectangle dimensions
    void AddEntry(void *entry, const float minX, const float minY, const float maxX, const float maxY);

#ifdef _USE_ORDERED_LIST

    // Removes a pointer, as above
    void RemoveEntry(void *entry, const float minX, const float minY, const float maxX, const float maxY);

    // Adds and removes in one pass, more efficient than calling both functions consecutively
    void MoveEntry(void *entry, const float sourceMinX, const float sourceMinY, const float sourceMaxX, const float sourceMaxY,
        const float destMinX, const float destMinY, const float destMaxX, const float destMaxY);

#endif

    // Adds to intersectionList all entries in a certain radius
    void GetEntries(DataStructures::List<void*>& intersectionList, const float minX, const float minY, const float maxX, const float maxY);

    void Clear(void);

protected:
    int WorldToCellX(const float input) const;
    int WorldToCellY(const float input) const;
    int WorldToCellXOffsetAndClamped(const float input) const;
    int WorldToCellYOffsetAndClamped(const float input) const;

    // Returns true or false if a position crosses cells in the grid.  If false, you don't need to move entries
    bool PositionCrossesCells(const float originX, const float originY, const float destinationX, const float destinationY) const;

    float cellOriginX, cellOriginY;
    float cellWidth, cellHeight;
    float invCellWidth, invCellHeight;
    float gridWidth, gridHeight;
    int gridCellWidthCount, gridCellHeightCount;


    // int gridWidth, gridHeight;

#ifdef _USE_ORDERED_LIST
    DataStructures::OrderedList<void*, void*>* grid;
#else
    DataStructures::List<void*>* grid;
#endif
};

#endif