Aquaria/BBGE/Interpolators.h

#ifndef BBGE_INTERPOLATORS_H
#define BBGE_INTERPOLATORS_H

#include <algorithm> // std::pair
#include <vector>
#include "Vector.h"

class CosineInterpolator
{
public:
    CosineInterpolator();
    void clear();
    void setPoints(const Vector *p, size_t n);
    float operator()(float x) const;
    void interpolateRange(float *ys, const float *xs, size_t n);

private:

    std::vector<std::pair<float, float> > pxy;
};

class BSpline2D
{
public:
    BSpline2D();

    // # of control points on each axis
    void resize(size_t cx, size_t cy, unsigned degx, unsigned degy);
    void recalc(Vector *dst, size_t xres, size_t yres, const Vector *controlpoints);

    void reset(Vector *controlpoints);

    inline size_t ctrlX() const { return _cpx; }
    inline size_t ctrlY() const { return _cpy; }

    inline unsigned degX() const { return _degx; }
    inline unsigned degY() const { return _degy; }

private:
    size_t _cpx, _cpy; // # of control points
    unsigned _degx, _degy;
    float _tmin, _tmax;
    std::vector<float> knotsX, knotsY;
};


class BSpline2DWithPoints : public BSpline2D
{
public:

    void resize(size_t cx, size_t cy, unsigned degx, unsigned degy);
    void recalc(Vector *dst, size_t xres, size_t yres);

    void reset();

    std::vector<Vector> controlpoints;

    inline Vector& controlpoint(size_t x, size_t y)
    {
        return controlpoints[y * ctrlX() + x];
    }
};

#endif