#ifndef jbt_distance_h
#define jbt_distance_h

#include <jgl/jgl.h>

class jbt_primitive;


class jbt_distance
{
public:

    jbt_distance() : refcnt(0), kx(1), ky(1), kz(1) 
        {}
    virtual ~jbt_distance() {};

    void setScale( jFlt _kx, jFlt _ky, jFlt _kz )
        { kx = _kx, ky = _ky, kz = _kz; }

    jFlt scaleX() const { return kx; }

    jFlt scaleY() const { return ky; }

    jFlt scaleZ() const { return kz; }


    virtual jFlt f( const jVec3& );
    

    virtual jVec3 df(const jVec3&, jFlt );

    virtual jgl_algebraic* expression( jgl_algebraic*,
                                       jgl_algebraic*,
                                       jgl_algebraic* ) const;

    static jbt_distance D;

protected:
    
    jFlt kx,ky,kz;

private:
    
    friend class jbt_primitive;
    friend class jbt_build;
    int refcnt;

};


class jbt_lmetric_distance : public jbt_distance
{
public:
    

    jbt_lmetric_distance( jFlt _n ) : n(_n) { n_1 = 1.0/n; }
    
    jFlt f( const jVec3& );
    
    jVec3 df( const jVec3&, jFlt );

    jgl_algebraic* expression( jgl_algebraic*,
                               jgl_algebraic*,
                               jgl_algebraic* ) const;

    void setN( jFlt _n ) { n = _n, n_1 = 1.0/_n; }

protected:
    jFlt n, n_1;

};


class jbt_superquadric_distance : public jbt_distance
{
public:
    

    jbt_superquadric_distance( jFlt _ew = 2, jFlt _ns = 2, int _axis = 2 )
        : ew(_ew), ns(_ns), axis(_axis) 
    { ew_2 = 2.0/ew, ns_2 = 2.0/ns, ns_ew = ew/ns; }
    
    jFlt f( const jVec3& );
    
    jVec3 df( const jVec3&, jFlt);

//    jgl_algebraic* equation() const;

protected:
    jFlt ew,ns, ew_2, ns_2, ns_ew;
    int axis;
};


class jbt_anisotropic_lmetric_distance : public jbt_lmetric_distance
{
public:


    jbt_anisotropic_lmetric_distance( const jNorm3& N,
                                      jFlt p0, jFlt p1,
                                      jFlt a = 0, jFlt b = 1);
    jFlt f( const jVec3& );
    
    jVec3 df( const jVec3&, jFlt );

private:

    jNorm3 N;
    jFlt p0,p1,a,b;
};


class jbt_anisotropic_superquadric_distance : public jbt_superquadric_distance
{
public:


    jbt_anisotropic_superquadric_distance( const jNorm3& N,
                                           jFlt ew0, jFlt ns0,
                                           jFlt ew1, jFlt ns1, int axis = 2,
                                           jFlt a = 0, jFlt b = 1);
    jFlt f( const jVec3& );
    
    jVec3 df( const jVec3&, jFlt );

private:

    jNorm3 N;
    jFlt ew0,ns0,ew1,ns1;
    jFlt a,b;
};

#endif