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/** @file
* @brief Circle shape
*//*
* Authors:
* Marco Cecchetti <mrcekets at gmail.com>
* Krzysztof Kosiński <tweenk.pl@gmail.com>
*
* Copyright 2008-2014 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_CIRCLE_H
#define LIB2GEOM_SEEN_CIRCLE_H
#include <2geom/forward.h>
#include <2geom/intersection.h>
#include <2geom/point.h>
#include <2geom/rect.h>
#include <2geom/transforms.h>
namespace Geom {
class EllipticalArc;
/** @brief Set of all points at a fixed distance from the center
* @ingroup Shapes */
class Circle
: boost::equality_comparable1< Circle
, MultipliableNoncommutative< Circle, Translate
, MultipliableNoncommutative< Circle, Rotate
, MultipliableNoncommutative< Circle, Zoom
> > > >
{
Point _center;
Coord _radius;
public:
Circle() {}
Circle(Coord cx, Coord cy, Coord r)
: _center(cx, cy), _radius(r)
{}
Circle(Point const ¢er, Coord r)
: _center(center), _radius(r)
{}
Circle(Coord A, Coord B, Coord C, Coord D) {
setCoefficients(A, B, C, D);
}
// Construct the unique circle passing through three points.
//Circle(Point const &a, Point const &b, Point const &c);
Point center() const { return _center; }
Coord center(Dim2 d) const { return _center[d]; }
Coord radius() const { return _radius; }
Coord area() const { return M_PI * _radius * _radius; }
bool isDegenerate() const { return _radius == 0; }
void setCenter(Point const &p) { _center = p; }
void setRadius(Coord c) { _radius = c; }
Rect boundsFast() const;
Rect boundsExact() const { return boundsFast(); }
Point initialPoint() const;
Point finalPoint() const { return initialPoint(); }
Point pointAt(Coord t) const;
Coord valueAt(Coord t, Dim2 d) const;
Coord timeAt(Point const &p) const;
Coord nearestTime(Point const &p) const;
bool contains(Point const &p) const { return distance(p, _center) <= _radius; }
bool contains(Rect const &other) const;
bool contains(Circle const &other) const;
bool intersects(Line const &l) const;
bool intersects(LineSegment const &l) const;
bool intersects(Circle const &other) const;
std::vector<ShapeIntersection> intersect(Line const &other) const;
std::vector<ShapeIntersection> intersect(LineSegment const &other) const;
std::vector<ShapeIntersection> intersect(Circle const &other) const;
// build a circle by its implicit equation:
// Ax^2 + Ay^2 + Bx + Cy + D = 0
void setCoefficients(Coord A, Coord B, Coord C, Coord D);
void coefficients(Coord &A, Coord &B, Coord &C, Coord &D) const;
std::vector<Coord> coefficients() const;
Zoom unitCircleTransform() const;
Zoom inverseUnitCircleTransform() const;
EllipticalArc *
arc(Point const& initial, Point const& inner, Point const& final) const;
D2<SBasis> toSBasis() const;
Circle &operator*=(Translate const &t) {
_center *= t;
return *this;
}
Circle &operator*=(Rotate const &) {
return *this;
}
Circle &operator*=(Zoom const &z) {
_center *= z;
_radius *= z.scale();
return *this;
}
bool operator==(Circle const &other) const;
/** @brief Fit the circle to the passed points using the least squares method.
* @param points Samples at the perimeter of the circle */
void fit(std::vector<Point> const &points);
};
bool are_near(Circle const &a, Circle const &b, Coord eps=EPSILON);
std::ostream &operator<<(std::ostream &out, Circle const &c);
template <>
struct ShapeTraits<Circle> {
typedef Coord TimeType;
typedef Interval IntervalType;
typedef Ellipse AffineClosureType;
typedef Intersection<> IntersectionType;
};
} // end namespace Geom
#endif // LIB2GEOM_SEEN_CIRCLE_H
/*
Local Variables:
mode:c++
c-file-style:"stroustrup"
c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
indent-tabs-mode:nil
fill-column:99
End:
*/
// vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:fileencoding=utf-8:textwidth=99 :
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