Adding upstream version 1.3.upstream/1.3upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 192 insertions, 0 deletions

diff --git a/include/2geom/ray.h b/include/2geom/ray.h
new file mode 100644
index 0000000..4e60fd8
--- /dev/null
+++ b/include/2geom/ray.h
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+/**
+ * \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 :