ellipse.h

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/*
 * Authors:
 *   Marco Cecchetti <mrcekets at gmail.com>
 *   Krzysztof Kosiński <tweenk.pl@gmail.com>
 *
 * Copyright 2008  authors
 *
 * This library is free software; you can redistribute it and/or
 * modify it either under the terms of the GNU Lesser General Public
 * License version 2.1 as published by the Free Software Foundation
 * (the "LGPL") or, at your option, under the terms of the Mozilla
 * Public License Version 1.1 (the "MPL"). If you do not alter this
 * notice, a recipient may use your version of this file under either
 * the MPL or the LGPL.
 *
 * You should have received a copy of the LGPL along with this library
 * in the file COPYING-LGPL-2.1; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 * You should have received a copy of the MPL along with this library
 * in the file COPYING-MPL-1.1
 *
 * The contents of this file are subject to the Mozilla Public License
 * Version 1.1 (the "License"); you may not use this file except in
 * compliance with the License. You may obtain a copy of the License at
 * http://www.mozilla.org/MPL/
 *
 * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY
 * OF ANY KIND, either express or implied. See the LGPL or the MPL for
 * the specific language governing rights and limitations.
 */
 
 
#ifndef LIB2GEOM_SEEN_ELLIPSE_H
#define LIB2GEOM_SEEN_ELLIPSE_H
 
#include <vector>
#include <2geom/angle.h>
#include <2geom/bezier-curve.h>
#include <2geom/exception.h>
#include <2geom/forward.h>
#include <2geom/line.h>
#include <2geom/transforms.h>
 
namespace Geom {
 
class EllipticalArc;
class Circle;
 
class Ellipse
    : boost::multipliable< Ellipse, Translate
    , boost::multipliable< Ellipse, Scale
    , boost::multipliable< Ellipse, Rotate
    , boost::multipliable< Ellipse, Zoom
    , boost::multipliable< Ellipse, Affine
    , boost::equality_comparable< Ellipse
      > > > > > >
{
    Point _center;
    Point _rays;
    Angle _angle;
public:
    Ellipse() {}
    Ellipse(Point const &c, Point const &r, Coord angle)
        : _center(c)
        , _rays(r)
        , _angle(angle)
    {}
    Ellipse(Coord cx, Coord cy, Coord rx, Coord ry, Coord angle)
        : _center(cx, cy)
        , _rays(rx, ry)
        , _angle(angle)
    {}
    Ellipse(double A, double B, double C, double D, double E, double F) {
        setCoefficients(A, B, C, D, E, F);
    }
    Ellipse(Geom::Circle const &c);
 
    void set(Point const &c, Point const &r, Coord angle) {
        _center = c;
        _rays = r;
        _angle = angle;
    }
    void set(Coord cx, Coord cy, Coord rx, Coord ry, Coord a) {
        _center[X] = cx;
        _center[Y] = cy;
        _rays[X] = rx;
        _rays[Y] = ry;
        _angle = a;
    }
    void setCoefficients(double A, double B, double C, double D, double E, double F);
    void setCenter(Point const &p) { _center = p; }
    void setCenter(Coord cx, Coord cy) { _center[X] = cx; _center[Y] = cy; }
    void setRays(Point const &p) { _rays = p; }
    void setRays(Coord x, Coord y) { _rays[X] = x; _rays[Y] = y; }
    void setRay(Coord r, Dim2 d) { _rays[d] = r; }
    void setRotationAngle(Angle a) { _angle = a; }
 
    Point center() const { return _center; }
    Coord center(Dim2 d) const { return _center[d]; }
    Point rays() const { return _rays; }
    Coord ray(Dim2 d) const { return _rays[d]; }
    Angle rotationAngle() const { return _angle; }
    Point initialPoint() const;
    Point finalPoint() const { return initialPoint(); }
 
    void fit(std::vector<Point> const& points);
 
    EllipticalArc *arc(Point const &ip, Point const &inner, Point const &fp);
 
    Ellipse canonicalForm() const;
    void makeCanonical();
 
    Affine unitCircleTransform() const;
    Affine inverseUnitCircleTransform() const;
 
    LineSegment majorAxis() const { return ray(X) >= ray(Y) ? axis(X) : axis(Y); }
    LineSegment minorAxis() const { return ray(X) < ray(Y) ? axis(X) : axis(Y); }
    LineSegment semimajorAxis(int sign = 1) const {
        return ray(X) >= ray(Y) ? semiaxis(X, sign) : semiaxis(Y, sign);
    }
    LineSegment semiminorAxis(int sign = 1) const {
        return ray(X) < ray(Y) ? semiaxis(X, sign) : semiaxis(Y, sign);
    }
    LineSegment axis(Dim2 d) const;
    LineSegment semiaxis(Dim2 d, int sign = 1) const;
 
    Rect boundsExact() const;
 
    Rect boundsFast() const;
 
    std::vector<double> coefficients() const;
    void coefficients(Coord &A, Coord &B, Coord &C, Coord &D, Coord &E, Coord &F) const;
 
    Point pointAt(Coord t) const;
    Coord valueAt(Coord t, Dim2 d) const;
 
    Coord timeAt(Point const &p) const;
 
    Point unitTangentAt(Coord t) const;
 
    bool contains(Point const &p) const;
 
    std::vector<ShapeIntersection> intersect(Line const &line) const;
    std::vector<ShapeIntersection> intersect(LineSegment const &seg) const;
    std::vector<ShapeIntersection> intersect(Ellipse const &other) const;
    std::vector<ShapeIntersection> intersect(D2<Bezier> const &other) const;
 
    Ellipse &operator*=(Translate const &t) {
        _center *= t;
        return *this;
    }
    Ellipse &operator*=(Scale const &s) {
        _center *= s;
        _rays *= s;
        return *this;
    }
    Ellipse &operator*=(Zoom const &z) {
        _center *= z;
        _rays *= z.scale();
        return *this;
    }
    Ellipse &operator*=(Rotate const &r);
    Ellipse &operator*=(Affine const &m);
 
    bool operator==(Ellipse const &other) const;
};
 
bool are_near(Ellipse const &a, Ellipse const &b, Coord precision = EPSILON);
 
std::ostream &operator<<(std::ostream &out, Ellipse const &e);
 
} // end namespace Geom
 
#endif // LIB2GEOM_SEEN_ELLIPSE_H
 
/*
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  c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
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  End:
*/
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