LodGrid.h

//
// LodGrid.h
//
// Copyright (c) 2001-2007 Virtual Terrain Project
// Free for all uses, see license.txt for details.
//

#ifndef LODGRIDH
#define LODGRIDH

class vtGeode;
class vtTransform;
class vtHeightField3d;


class vtLodGrid : public vtGroup
{
public:
    vtLodGrid();
    virtual void Setup(const FPoint3 &origin, const FPoint3 &size,
        int iDimension, float fLODDistance, vtHeightField3d *pHF = NULL) = 0;

    // methods
    bool AddToGrid(osg::Node *pNode);
    void RemoveFromGrid(osg::Node *pNode);

    virtual void SetDistance(float fLODDistance) = 0;
    float GetDistance() { return m_fLODDistance; }
    int GetDimension() { return m_dim; }
    FPoint3 GetCellSize() { return m_step; }

protected:
    FPoint3 m_origin;
    FPoint3 m_size;
    FPoint3 m_step;

    int m_dim;
    float m_fLODDistance;
    vtHeightField3d *m_pHeightField;

    virtual osg::Group *FindCellParent(const FPoint3 &point) = 0;
    virtual void AllocateCell(int a, int b) = 0;
    virtual osg::Group *GetCell(int a, int b) = 0;
    void DetermineCell(const FPoint3 &pos, int &a, int &b);
};

class vtSimpleLodGrid : public vtLodGrid
{
public:
    vtSimpleLodGrid();
    ~vtSimpleLodGrid();

    void Setup(const FPoint3 &origin, const FPoint3 &size,
        int iDimension, float fLODDistance, vtHeightField3d *pHF = NULL);

    // methods
    void SetDistance(float fLODDistance);

protected:
    vtLOD **m_pCells;

    osg::Group *FindCellParent(const FPoint3 &point);
    void AllocateCell(int a, int b);
    osg::Group *GetCell(int a, int b);
};
  // sg

#endif  // LODGRIDH