/*
Copyright (C) 1998 Jürgen Hochwald <juergen.hochwald@privat.kkf.net>

This library is free software; you can redistribute it and/or
modify it under the terms of the GNU Library General Public
License as published by the Free Software Foundation; either
version 2 of the License, or (at your option) any later version.

This library 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
Library General Public License for more details.

You should have received a copy of the GNU General Public License
along with this library; see the file COPYING.  If not, write to
the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
Boston, MA 02110-1301, USA.
*/



#ifndef SPLINE_H
#define SPLINE_H

#include <stdlib.h>
#include <vector>

class Spline
{
	struct Group
	{
		double x, y, y2;
	};
	
	std::vector<Spline::Group> mPoints;
	bool mRecalc;
	double yp1;
	double ypn;
	
	// stupid AIX[?] compiler won't let me give it a value here
	static const bool natural;

public:
	Spline();
	Spline(const Spline &copy);
	
	Spline &operator =(const Spline &copy);
	~Spline();
	
	/**
	 * if the curve had @p count points, return them
	 **/
	std::vector<double> points(int count) const;
	
	void add(double x, double y);
	double spline(double xarg) const;
	double operator[] (double xarg) const { return spline(xarg); }
	int numPoints() const { return mPoints.size(); }
	double x(int num) const;
	double y(int num) const;

	void clear();
	
private:
	void calcSpline() const
	{
		const_cast<Spline*>(this)->calcSpline();
	}
	void calcSpline();
	
};

#endif