Adding upstream version 1.3.upstream/1.3upstream

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

1 files changed, 147 insertions, 0 deletions

diff --git a/include/2geom/intersection.h b/include/2geom/intersection.h
new file mode 100644
index 0000000..8a23811
--- /dev/null
+++ b/include/2geom/intersection.h
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+/**
+ * \file
+ * \brief Intersection utilities
+ *//*
+ * Authors:
+ *   Krzysztof Kosiński <tweenk.pl@gmail.com>
+ * 
+ * Copyright 2015 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 SEEN_LIB2GEOM_INTERSECTION_H
+#define SEEN_LIB2GEOM_INTERSECTION_H
+
+#include <2geom/coord.h>
+#include <2geom/point.h>
+
+namespace Geom {
+
+
+/** @brief Intersection between two shapes.
+ */
+template <typename TimeA = Coord, typename TimeB = TimeA>
+class Intersection
+    : boost::totally_ordered< Intersection<TimeA, TimeB> >
+{
+public:
+    /** @brief Construct from shape references and time values.
+     * By default, the intersection point will be halfway between the evaluated
+     * points on the two shapes. */
+    template <typename TA, typename TB>
+    Intersection(TA const &sa, TB const &sb, TimeA const &ta, TimeB const &tb)
+        : first(ta)
+        , second(tb)
+        , _point(lerp(0.5, sa.pointAt(ta), sb.pointAt(tb)))
+    {}
+
+    /// Additionally report the intersection point.
+    Intersection(TimeA const &ta, TimeB const &tb, Point const &p)
+        : first(ta)
+        , second(tb)
+        , _point(p)
+    {}
+
+    /// Intersection point, as calculated by the intersection algorithm.
+    Point point() const {
+        return _point;
+    }
+    /// Implicit conversion to Point.
+    operator Point() const {
+        return _point;
+    }
+
+    friend inline void swap(Intersection &a, Intersection &b) {
+        using std::swap;
+        swap(a.first, b.first);
+        swap(a.second, b.second);
+        swap(a._point, b._point);
+    }
+
+    bool operator==(Intersection const &other) const {
+        if (first != other.first) return false;
+        if (second != other.second) return false;
+        return true;
+    }
+    bool operator<(Intersection const &other) const {
+        if (first < other.first) return true;
+        if (first == other.first && second < other.second) return true;
+        return false;
+    }
+
+public:
+    /// First shape and time value.
+    TimeA first;
+    /// Second shape and time value.
+    TimeB second;
+private:
+    // Recalculation of the intersection point from the time values is in many cases
+    // less precise than the value obtained directly from the intersection algorithm,
+    // so we need to store it.
+    Point _point;
+};
+
+
+// TODO: move into new header?
+template <typename T>
+struct ShapeTraits {
+    typedef Coord TimeType;
+    typedef Interval IntervalType;
+    typedef T AffineClosureType;
+    typedef Intersection<> IntersectionType;
+};
+
+template <typename A, typename B> inline
+std::vector< Intersection<A, B> > transpose(std::vector< Intersection<B, A> > const &in) {
+    std::vector< Intersection<A, B> > result;
+    for (std::size_t i = 0; i < in.size(); ++i) {
+        result.push_back(Intersection<A, B>(in[i].second, in[i].first, in[i].point()));
+    }
+    return result;
+}
+
+template <typename T> inline
+void transpose_in_place(std::vector< Intersection<T, T> > &xs) {
+    for (std::size_t i = 0; i < xs.size(); ++i) {
+        std::swap(xs[i].first, xs[i].second);
+    }
+}
+
+typedef Intersection<> ShapeIntersection;
+
+
+} // namespace Geom
+
+#endif // SEEN_LIB2GEOM_INTERSECTION_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 :