/*! ========================================================================
** Extended Template Library
** Hermite Template Class Implementation
** $Id$
**
** Copyright (c) 2002 Robert B. Quattlebaum Jr.
**
** This package is free software; you can redistribute it and/or
** modify it under the terms of the GNU General Public License as
** published by the Free Software Foundation; either version 2 of
** the License, or (at your option) any later version.
**
** This package is distributed in the hope that it will be useful,
** but WITHOUT ANY WARRANTY; without even the implied warranty of
** MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
** General Public License for more details.
**
** === N O T E S ===========================================================
**
** This is an internal header file, included by other ETL headers.
** You should not attempt to use it directly.
**
** ========================================================================= */
/* === 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 ======================================= */
namespace etl {
/*
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();
}
};
};
/* === E X T E R N S ======================================================= */
/* === E N D =============================================================== */
#endif