DynTerrain.h

//
// DynTerrain class : Dynamically rendering terrain
//
// Copyright (c) 2001-2007 Virtual Terrain Project
// Free for all uses, see license.txt for details.
//

#ifndef DYNTERRAINH
#define DYNTERRAINH

#include "vtdata/ElevationGrid.h"
#include "vtdata/HeightField.h"


// A set of errors that may be returned from the dynamic terrain classes.
enum DTErr
{
    DTErr_OK,
    DTErr_EMPTY_EXTENTS,
    DTErr_NOTSQUARE,
    DTErr_NOTPOWER2,
    DTErr_NOMEM
};

class vtDynTerrainGeom : public vtDynGeom, public vtHeightFieldGrid3d
{
public:
    vtDynTerrainGeom();

    // Each subclass must implement this initialization method
    virtual DTErr Init(const vtElevationGrid *pGrid, float fZScale) = 0;
    virtual void Init2() {}
    DTErr BasicInit(const vtElevationGrid *pGrid);
    virtual void SetVerticalExag(float fExag) {}
    virtual float GetVerticalExag() const = 0;

    virtual void SetPolygonTarget(int iPolygonCount);
    int GetPolygonTarget();

    int GetNumDrawnTriangles();

    void SetDetailMaterial(vtMaterial *pApp, float fTiling, float fDistance);
    void EnableDetail(bool bOn);
    bool GetDetail() { return m_bDetailTexture; }
    void SetupTexGen(float fTiling);
    void DisableTexGen();

    // overrides for vtDynGeom
    void DoCalcBoundBox(FBox3 &box);
    void DoCull(const vtCamera *pCam);

    // overrides for HeightField
    bool FindAltitudeOnEarth(const DPoint2 &p, float &fAltitude, bool bTrue = false) const;

    // overrides for HeightField3d
    bool FindAltitudeAtPoint(const FPoint3 &p3, float &fAltitude,
        bool bTrue = false, int iCultureFlags = 0,
        FPoint3 *vNormal = NULL) const;

    // overridables
    virtual void DoCulling(const vtCamera *pCam) = 0;
    virtual void SetElevation(int i, int j, float fValue, bool bTrue = false) {}

    // control
    void SetCull(bool bOnOff);
    void CullOnce();

    void PreRender() const;
    void PostRender() const;

    // statistics
    int m_iTotalTriangles;
    int m_iDrawnTriangles;

protected:
    // tables for quick conversion from x,y index to output X,Z coordinates
    float   *m_fXLookup, *m_fZLookup;

    // this determines the overall level of detail
    int     m_iPolygonTarget;

    // flags
    bool m_bCulleveryframe;
    bool m_bCullonce;

    // detail texture
    float m_fDetailTiling;
    float m_fDetailDistance;
    bool m_bDetailTexture;
    vtMaterial *m_pDetailMat;

protected:
    ~vtDynTerrainGeom();
};
typedef osg::ref_ptr<vtDynTerrainGeom> vtDynTerrainGeomPtr;
    // Group dynterr

#endif  // DYNTERRAINH