#ifndef _2GEOM_BEZIER_CURVE_H_

#define _2GEOM_BEZIER_CURVE_H_

#include <2geom/curve.h>

#include <2geom/sbasis-curve.h> // for non-native winding method

#include <2geom/bezier.h>

#include <algorithm>

namespace Geom

{

template <unsigned order>

class BezierCurve : public Curve {

private:

D2<Bezier > inner;

public:

template <unsigned required_degree>

static void assert_degree(BezierCurve<required_degree> const *) {}

BezierCurve() : inner(Bezier::Order(order), Bezier::Order(order)) {

}

explicit BezierCurve(D2<Bezier > const &x) : inner(x) {}

BezierCurve(Bezier x, Bezier y) : inner(x, y) {}

// default copy

// default assign

BezierCurve(Point c0, Point c1) {

assert_degree<1>(this);

for(unsigned d = 0; d < 2; d++)

inner[d] = Bezier(c0[d], c1[d]);

}

BezierCurve(Point c0, Point c1, Point c2) {

assert_degree<2>(this);

for(unsigned d = 0; d < 2; d++)

inner[d] = Bezier(c0[d], c1[d], c2[d]);

}

BezierCurve(Point c0, Point c1, Point c2, Point c3) {

assert_degree<3>(this);

for(unsigned d = 0; d < 2; d++)

inner[d] = Bezier(c0[d], c1[d], c2[d], c3[d]);

}

unsigned degree() const { return order; }

Curve *duplicate() const { return new BezierCurve(*this); }

Point initialPoint() const { return inner.at0(); }

Point finalPoint() const { return inner.at1(); }

bool isDegenerate() const { return inner.isConstant(); }

void setInitial(Point v) { setPoint(0, v); }

void setFinal(Point v) { setPoint(order, v); }

void setPoint(unsigned ix, Point v) { inner[X].setPoint(ix, v[X]); inner[Y].setPoint(ix, v[Y]); }

Point const operator[](unsigned ix) const { return Point(inner[X][ix], inner[Y][ix]); }

Rect boundsFast() const { return bounds_fast(inner); }

Rect boundsExact() const { return bounds_exact(inner); }

Rect boundsLocal(Interval i, unsigned deg) const {

if(i.min() == 0 && i.max() == 1) return boundsFast();

if(deg == 0) return bounds_local(inner, i);

// TODO: UUUUUUGGGLLY

if(deg == 1 && order > 1) return Rect(bounds_local(Geom::derivative(inner[X]), i),

bounds_local(Geom::derivative(inner[Y]), i));

return Rect(Interval(0,0), Interval(0,0));

}

int winding(Point p) const {

return SBasisCurve(toSBasis()).winding(p);

}

std::vector<double>

roots(double v, Dim2 d) const {

return (inner[d] - v).roots();

}

double nearestPoint( Point const& p, double from = 0, double to = 1 ) const

{

return Curve::nearestPoint(p, from, to);

}

void setPoints(std::vector<Point> ps) {

for(unsigned i = 0; i <= order; i++) {

setPoint(i, ps[i]);

}

}

std::vector<Point> points() const { return bezier_points(inner); }

std::pair<BezierCurve<order>, BezierCurve<order> > subdivide(Coord t) const {

std::pair<Bezier, Bezier > sx = inner[X].subdivide(t), sy = inner[Y].subdivide(t);

return std::pair<BezierCurve<order>, BezierCurve<order> >(

BezierCurve<order>(sx.first, sy.first),

BezierCurve<order>(sx.second, sy.second));

}

Curve *portion(double f, double t) const {

return new BezierCurve(Geom::portion(inner, f, t));

}

Curve *reverse() const {

return new BezierCurve(Geom::reverse(inner));

}

Curve *transformed(Matrix const &m) const {

BezierCurve *ret = new BezierCurve();

std::vector<Point> ps = points();

for(unsigned i = 0; i <= order; i++) ps[i] = ps[i] * m;

ret->setPoints(ps);

return ret;

}

Curve *derivative() const {

if(order > 1)

return new BezierCurve<order-1>(Geom::derivative(inner[X]), Geom::derivative(inner[Y]));

else if (order == 1) {

double dx = inner[X][1] - inner[X][0], dy = inner[Y][1] - inner[Y][0];

return new BezierCurve<1>(Point(dx,dy),Point(dx,dy));

}

}

Point pointAt(double t) const { return inner.valueAt(t); }

std::vector<Point> pointAndDerivatives(Coord t, unsigned n) const { return inner.valueAndDerivatives(t, n); }

double valueAt(double t, Dim2 d) const { return inner[d].valueAt(t); }

D2<SBasis> toSBasis() const {return inner.toSBasis(); }

protected:

BezierCurve(Point c[]) {

Coord x[order+1], y[order+1];

for(unsigned i = 0; i <= order; i++) {

x[i] = c[i][X]; y[i] = c[i][Y];

}

inner = Bezier(x, y);

}

};

template<> class BezierCurve<0> : public BezierCurve<1> { public: BezierCurve(); BezierCurve(Bezier x, Bezier y); };

typedef BezierCurve<1> LineSegment;

typedef BezierCurve<2> QuadraticBezier;

typedef BezierCurve<3> CubicBezier;

template<>

double LineSegment::nearestPoint(Point const& p, double from, double to) const

{

if ( from > to ) std::swap(from, to);

Point ip = pointAt(from);

Point fp = pointAt(to);

Point v = fp - ip;

double l2v = L2sq(v);

if(l2v == 0) return 0;

double t = dot( p - ip, v ) / l2v;

if ( t <= 0 ) return from;

else if ( t >= 1 ) return to;

else return from + t*(to-from);

}

Point middle_point(LineSegment const& _segment)

{

return ( _segment.initialPoint() + _segment.finalPoint() ) / 2;

}

double length(LineSegment const& _segment)

{

return distance(_segment.initialPoint(), _segment.finalPoint());

}

} // end namespace Geom

#endif // _2GEOM_BEZIER_CURVE_H_