/* This file is part of the Palabos library.
 *
 * The Palabos softare is developed since 2011 by FlowKit-Numeca Group Sarl
 * (Switzerland) and the University of Geneva (Switzerland), which jointly
 * own the IP rights for most of the code base. Since October 2019, the
 * Palabos project is maintained by the University of Geneva and accepts
 * source code contributions from the community.
 * 
 * Contact:
 * Jonas Latt
 * Computer Science Department
 * University of Geneva
 * 7 Route de Drize
 * 1227 Carouge, Switzerland
 * jonas.latt@unige.ch
 *
 * The most recent release of Palabos can be downloaded at 
 * <https://palabos.unige.ch/>
 *
 * The library Palabos is free software: you can redistribute it and/or
 * modify it under the terms of the GNU Affero General Public License as
 * published by the Free Software Foundation, either version 3 of the
 * License, or (at your option) any later version.
 *
 * The 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 Affero General Public License for more details.
 *
 * You should have received a copy of the GNU Affero General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
*/

#ifndef INTERPOLATION_2D_H
#define INTERPOLATION_2D_H

#include <string>
#include <vector>

namespace plb {

template<typename T>
class Interpolation2D {
public:
    Interpolation2D() { }
    Interpolation2D(std::string fname);
    Interpolation2D(std::vector<T> const& x_, std::vector<T> const& y_, std::vector<std::vector<T> > const& f_);
    virtual ~Interpolation2D() { }
    virtual Interpolation2D<T>* clone() const =0;
    std::vector<T> const& getCoordinatesX() const { return x; }
    std::vector<T>& getCoordinatesX() { return x; }
    std::vector<T> const& getCoordinatesY() const { return y; }
    std::vector<T>& getCoordinatesY() { return y; }
    std::vector<std::vector<T> > const& getFunctionValues() const { return f; }
    std::vector<std::vector<T> >& getFunctionValues() { return f; }
    void transformCoordinatesX(T scale, T offset);
    void transformCoordinatesY(T scale, T offset);
    void transformFunctionValues(T scale, T offset);
    void exportInXYZFormat(std::string fname, int numDecimalDigits = 10) const;
    virtual T getFunctionValue(T x0, T y0) const =0;
private:
    std::vector<T> x, y;
    std::vector<std::vector<T> > f;
};

template<typename T>
class LinearInterpolation2D : public Interpolation2D<T> {
public:
    LinearInterpolation2D()
        :Interpolation2D<T>(),
         icache(0),
         jcache(0)
    { }
    LinearInterpolation2D(std::string fname)
        :Interpolation2D<T>(fname),
         icache(0),
         jcache(0)
    { }
    LinearInterpolation2D(std::vector<T> const& x_, std::vector<T> const& y_, std::vector<std::vector<T> > const& f_)
        :Interpolation2D<T>(x_, y_, f_),
         icache(0),
         jcache(0)
    { }
    virtual ~LinearInterpolation2D() { }
    virtual LinearInterpolation2D<T>* clone() const;
    virtual T getFunctionValue(T x0, T y0) const;
private:
    plint bsrch(std::vector<T> const& v, T t, plint il, plint ih) const;
    void locate(std::vector<T> const& v, T& t, plint& cache) const;
private:
    mutable plint icache, jcache;
};

}  // namespace plb

#endif  // INTERPOLATION_2D_H
