// dHeightfield Collider

//  Martijn Buijs 2006 http://home.planet.nl/~buijs512/

// Based on Terrain & Cone contrib by:

//  Benoit CHAPEROT 2003-2004 http://www.jstarlab.com

#ifndef _DHEIGHTFIELD_H_

#define _DHEIGHTFIELD_H_

//------------------------------------------------------------------------------

#include <ode/common.h>

#include "collision_kernel.h"

#define HEIGHTFIELDMAXCONTACTPERCELL 10

//

// dxHeightfieldData

//

// Heightfield Data structure

//

struct dxHeightfieldData

{

    dReal m_fWidth;				// World space heightfield dimension on X axis

    dReal m_fDepth;				// World space heightfield dimension on Z axis

    dReal m_fSampleWidth;		// Vertex count on X axis edge (== m_vWidth / (m_nWidthSamples-1))

    dReal m_fSampleDepth;		// Vertex count on Z axis edge (== m_vDepth / (m_nDepthSamples-1))

    dReal m_fInvSampleWidth;		// Cache of inverse Vertex count on X axis edge (== m_vWidth / (m_nWidthSamples-1))

    dReal m_fInvSampleDepth;		// Cache of inverse Vertex count on Z axis edge (== m_vDepth / (m_nDepthSamples-1))

    dReal m_fHalfWidth;			// Cache of half of m_fWidth

    dReal m_fHalfDepth;			// Cache of half of m_fDepth

    dReal m_fMinHeight;        // Min sample height value (scaled and offset)

    dReal m_fMaxHeight;        // Max sample height value (scaled and offset)

    dReal m_fThickness;        // Surface thickness (added to bottom AABB)

    dReal m_fScale;            // Sample value multiplier

    dReal m_fOffset;           // Vertical sample offset

    int	m_nWidthSamples;       // Vertex count on X axis edge (number of samples)

    int	m_nDepthSamples;       // Vertex count on Z axis edge (number of samples)

    int m_bCopyHeightData;     // Do we own the sample data?

    int	m_bWrapMode;           // Heightfield wrapping mode (0=finite, 1=infinite)

    int m_nGetHeightMode;      // GetHeight mode ( 0=callback, 1=byte, 2=short, 3=float )

    const void* m_pHeightData; // Sample data array

    void* m_pUserData;         // Callback user data

    dContactGeom            m_contacts[HEIGHTFIELDMAXCONTACTPERCELL];

    dHeightfieldGetHeight* m_pGetHeightCallback;		// Callback pointer.

    dxHeightfieldData();

    ~dxHeightfieldData();

    void SetData( int nWidthSamples, int nDepthSamples,

        dReal fWidth, dReal fDepth,

        dReal fScale, dReal fOffset,

        dReal fThickness, int bWrapMode );

    void ComputeHeightBounds();

    bool IsOnHeightfield  ( const dReal * const CellOrigin, const dReal * const pos,  const bool isABC) const;

    bool IsOnHeightfield2  ( const dReal * const CellOrigin, const dReal * const pos,  const bool isABC) const;

    dReal GetHeight(int x, int z);

    dReal GetHeight(dReal x, dReal z);

};

class HeightFieldVertex;

class HeightFieldEdge;

class HeightFieldTriangle;

class HeightFieldVertex

{

public:

    HeightFieldVertex(){};

    dVector3 vertex;

    bool state;

};

class HeightFieldEdge

{

public:

    HeightFieldEdge(){};

    HeightFieldVertex   *vertices[2];

};

//

// HeightFieldTriangle

//

// HeightFieldTriangle composing heightfield mesh

//

class HeightFieldTriangle

{

public:

    HeightFieldTriangle(){};

    inline void setMinMax()

    {

        maxAAAB = vertices[0]->vertex[1] > vertices[1]->vertex[1] ? vertices[0]->vertex[1] : vertices[1]->vertex[1];

        maxAAAB = vertices[2]->vertex[1] > maxAAAB  ? vertices[2]->vertex[1] : maxAAAB;

    };

    HeightFieldVertex   *vertices[3];

    dReal               planeDef[4];

    dReal               maxAAAB;

    bool                isUp;

    bool                state;

};

//

// HeightFieldTriangle

//

// HeightFieldPlane composing heightfield mesh

//

class HeightFieldPlane

{

public:

    HeightFieldPlane():

      trianglelist(0),

      trianglelistReservedSize(0),

      trianglelistCurrentSize(0)

    {

    };

    ~HeightFieldPlane()

    {

        delete [] trianglelist;

    };

    inline void setMinMax()

    {

        const size_t asize = trianglelistCurrentSize;

        if (asize > 0)

        {  

            maxAAAB = trianglelist[0]->maxAAAB;

            for (size_t k = 1; asize > k; k++)

            {   

                if (trianglelist[k]->maxAAAB >  maxAAAB)

                    maxAAAB = trianglelist[k]->maxAAAB;

            }

        }

    };

    void resetTriangleListSize(const size_t newSize)

    {

        if (trianglelistReservedSize < newSize)

        {

            delete [] trianglelist;

            trianglelistReservedSize = newSize;

            trianglelist = new HeightFieldTriangle *[newSize];

        }

        trianglelistCurrentSize = 0;

    }

    void addTriangle(HeightFieldTriangle *tri)

    {

        trianglelist[trianglelistCurrentSize++] = tri;

    }

    HeightFieldTriangle **trianglelist;

    size_t              trianglelistReservedSize;

    size_t              trianglelistCurrentSize;

    dReal   maxAAAB;

    dReal   planeDef[4];

};

//

// dxHeightfield

//

// Heightfield geom structure

//

struct dxHeightfield : public dxGeom

{

    dxHeightfieldData* m_p_data;

    dxHeightfield( dSpaceID space, dHeightfieldDataID data, int bPlaceable );

    ~dxHeightfield();

    void computeAABB();

    int dCollideHeightfieldZone( const int minX, const int maxX, const int minZ, const int maxZ,  

        dxGeom *o2, const int numMaxContacts,

        int flags, dContactGeom *contact, int skip );

    void  resetHeightBuffer();

    void  sortPlanes(const size_t numPlanes);

    HeightFieldPlane    **tempPlaneBuffer;

    size_t              tempPlaneBufferSize;

    HeightFieldTriangle *tempTriangleBuffer;

    size_t              tempTriangleBufferSize;

    HeightFieldVertex   **tempHeightBuffer;

    size_t              tempHeightBufferSizeX;

    size_t              tempHeightBufferSizeZ;

};

//------------------------------------------------------------------------------

#endif //_DHEIGHTFIELD_H_