_hermite.h

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/* === S T A R T =========================================================== */

#ifndef __ETL__HERMITE_H
#define __ETL__HERMITE_H

/* === H E A D E R S ======================================================= */

#include "bezier"

/* === M A C R O S ========================================================= */

/* === T Y P E D E F S ===================================================== */

/* === C L A S S E S & S T R U C T S ======================================= */

_ETL_BEGIN_NAMESPACE

/*
template <typename T>
class hermite_base : std::unary_function<float,T>
{
public:
    typedef T value_type;
    typedef float time_type;
private:
    affine_combo<value_type,time_type> affine_func;
    value_type a,b,c,d;
    time_type r,s;

    value_type _coeff[3];
    time_type drs; // reciprocal of (s-r)
public:
    hermite_base():r(0.0),s(1.0) { drs=1.0/(s-r); }
    hermite_base(
        const value_type &a, const value_type &b, const value_type &c, const value_type &d,
        const time_type &r=0.0, const time_type &s=1.0):
        a(a),b(b),c(c),d(d),r(r),s(s) { sync(); }

    void sync(void)
    {
        drs=1.0/(s-r);
        _coeff[0]=           c;
        _coeff[1]=-d*1 - c*2 + b*3 - a*3;
        _coeff[2]= d*1 + c*1 - b*2 + a*2;
    }

    inline value_type
    operator()(time_type t)const
    { t-=r; t*=drs; return a + (_coeff[0]+(_coeff[1]+(_coeff[2])*t)*t)*t; }

    void set_rs(time_type new_r, time_type new_s) { r=new_r; s=new_s; drs=1.0/(s-r); }
    void set_r(time_type new_r) { r=new_r; drs=1.0/(s-r); }
    void set_s(time_type new_s) { s=new_s; drs=1.0/(s-r); }
    const time_type &get_r(void)const { return r; }
    const time_type &get_s(void)const { return s; }
    time_type get_dt(void)const { return s-r; }

    value_type &
    operator[](int i)
    { return (&a)[i]; }

    const value_type &
    operator[](int i) const
    { return (&a)[i]; }
};


template <typename T>
class hermite : public hermite_base<T>
{
public:
    typedef T value_type;
    typedef float time_type;



public:
    hermite() { }
    hermite(const value_type &p1, const value_type &p2, const value_type &t1, const value_type &t2):
        P1(p1),P2(p2),T1(t1),T2(t2) { sync(); }
    hermite(const value_type &p1, const value_type &p2):
        P1(p1),P2(p2),T1(p2-p1),T2(p2-p1) { sync(); }

    value_type P1,P2,T1,T2;

    value_type &p1(void) { return P1; }
    value_type &p2(void) { return P2; }
    value_type &t1(void) { return T1; }
    value_type &t2(void) { return T2; }

    void sync(void)
    {
//      hermite_base<T>::operator[](0)=P1;
//      bezier<T>::operator[](1)=P1+T1/3;
//      bezier<T>::operator[](2)=P2-T2/3;
//      bezier<T>::operator[](3)=P2;

        hermite_base<T>::operator[](0)=P1;
        hermite_base<T>::operator[](1)=P2;
        hermite_base<T>::operator[](2)=T1;
        hermite_base<T>::operator[](3)=T2;

        hermite_base<T>::sync();
    }

};

*/

template <typename V,typename T=float>
class hermite : public bezier<V,T>
{
public:
    typedef V value_type;
    typedef T time_type;



public:
    hermite() { }
    hermite(const value_type &p1, const value_type &p2, const value_type &t1, const value_type &t2):
        P1(p1),P2(p2),T1(t1),T2(t2) { sync(); }
    hermite(const value_type &p1, const value_type &p2):
        P1(p1),P2(p2),T1(p2-p1),T2(p2-p1) { sync(); }

    value_type P1,P2,T1,T2;

    value_type &p1() { return P1; }
    value_type &p2() { return P2; }
    value_type &t1() { return T1; }
    value_type &t2() { return T2; }

    void sync()
    {
        bezier<V,T>::operator[](0)=P1;
        bezier<V,T>::operator[](1)=P1+T1/3;
        bezier<V,T>::operator[](2)=P2-T2/3;
        bezier<V,T>::operator[](3)=P2;

        bezier<V,T>::sync();
    }
};

_ETL_END_NAMESPACE

/* === E X T E R N S ======================================================= */

/* === E N D =============================================================== */

#endif