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Diffstat (limited to 'src/3rdparty/2geom/include/2geom/ray.h')
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diff --git a/src/3rdparty/2geom/include/2geom/ray.h b/src/3rdparty/2geom/include/2geom/ray.h new file mode 100644 index 0000000..4e60fd8 --- /dev/null +++ b/src/3rdparty/2geom/include/2geom/ray.h @@ -0,0 +1,192 @@ +/** + * \file + * \brief Infinite straight ray + *//* + * Copyright 2008 Marco Cecchetti <mrcekets at gmail.com> + * + * 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_RAY_H +#define LIB2GEOM_SEEN_RAY_H + +#include <vector> +#include <2geom/point.h> +#include <2geom/bezier-curve.h> // for LineSegment +#include <2geom/exception.h> +#include <2geom/math-utils.h> +#include <2geom/transforms.h> +#include <2geom/angle.h> + +namespace Geom +{ + +/** + * @brief Straight ray from a specific point to infinity. + * + * Rays are "half-lines" - they begin at some specific point and extend in a straight line + * to infinity. + * + * @ingroup Primitives + */ +class Ray { +private: + Point _origin; + Point _vector; + +public: + Ray() : _origin(0,0), _vector(1,0) {} + Ray(Point const& origin, Coord angle) + : _origin(origin) + { + sincos(angle, _vector[Y], _vector[X]); + } + Ray(Point const& A, Point const& B) { + setPoints(A, B); + } + Point origin() const { return _origin; } + Point vector() const { return _vector; } + Point versor() const { return _vector.normalized(); } + void setOrigin(Point const &o) { _origin = o; } + void setVector(Point const& v) { _vector = v; } + Coord angle() const { return std::atan2(_vector[Y], _vector[X]); } + void setAngle(Coord a) { sincos(a, _vector[Y], _vector[X]); } + void setPoints(Point const &a, Point const &b) { + _origin = a; + _vector = b - a; + if (are_near(_vector, Point(0,0)) ) + _vector = Point(0,0); + else + _vector.normalize(); + } + bool isDegenerate() const { + return ( _vector[X] == 0 && _vector[Y] == 0 ); + } + Point pointAt(Coord t) const { + return _origin + _vector * t; + } + Coord valueAt(Coord t, Dim2 d) const { + return _origin[d] + _vector[d] * t; + } + std::vector<Coord> roots(Coord v, Dim2 d) const { + std::vector<Coord> result; + if ( _vector[d] != 0 ) { + double t = (v - _origin[d]) / _vector[d]; + if (t >= 0) result.push_back(t); + } else if (_vector[(d+1)%2] == v) { + THROW_INFINITESOLUTIONS(); + } + return result; + } + Coord nearestTime(Point const& point) const { + if ( isDegenerate() ) return 0; + double t = dot(point - _origin, _vector); + if (t < 0) t = 0; + return t; + } + Ray reverse() const { + Ray result; + result.setOrigin(_origin); + result.setVector(-_vector); + return result; + } + Curve *portion(Coord f, Coord t) const { + return new LineSegment(pointAt(f), pointAt(t)); + } + LineSegment segment(Coord f, Coord t) const { + return LineSegment(pointAt(f), pointAt(t)); + } + Ray transformed(Affine const& m) const { + return Ray(_origin * m, (_origin + _vector) * m); + } +}; // end class Ray + +inline +double distance(Point const& _point, Ray const& _ray) { + double t = _ray.nearestTime(_point); + return ::Geom::distance(_point, _ray.pointAt(t)); +} + +inline +bool are_near(Point const& _point, Ray const& _ray, double eps = EPSILON) { + return are_near(distance(_point, _ray), 0, eps); +} + +inline +bool are_same(Ray const& r1, Ray const& r2, double eps = EPSILON) { + return are_near(r1.vector(), r2.vector(), eps) + && are_near(r1.origin(), r2.origin(), eps); +} + +// evaluate the angle between r1 and r2 rotating r1 in cw or ccw direction on r2 +// the returned value is an angle in the interval [0, 2PI[ +inline +double angle_between(Ray const& r1, Ray const& r2, bool cw = true) { + double angle = angle_between(r1.vector(), r2.vector()); + if (angle < 0) angle += 2*M_PI; + if (!cw) angle = 2*M_PI - angle; + return angle; +} + +/** + * @brief Returns the angle bisector for the two given rays. + * + * @a r1 is rotated half the way to @a r2 in either clockwise or counter-clockwise direction. + * + * @pre Both passed rays must have the same origin. + * + * @remarks If the versors of both given rays point in the same direction, the direction of the + * angle bisector ray depends on the third parameter: + * - If @a cw is set to @c true, the returned ray will equal the passed rays @a r1 and @a r2. + * - If @a cw is set to @c false, the returned ray will go in the opposite direction. + * + * @throws RangeError if the given rays do not have the same origins + */ +inline +Ray make_angle_bisector_ray(Ray const& r1, Ray const& r2, bool cw = true) +{ + if ( !are_near(r1.origin(), r2.origin()) ) + { + THROW_RANGEERROR("passed rays do not have the same origin"); + } + + Ray bisector(r1.origin(), r1.origin() + r1.vector() * Rotate(angle_between(r1, r2) / 2.0)); + + return (cw ? bisector : bisector.reverse()); +} + +} // end namespace Geom + +#endif // LIB2GEOM_SEEN_RAY_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 : |