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+/**
+ * \file
+ * \brief  Simple closed interval class
+ *//*
+ * Copyright 2007 Michael Sloan <mgsloan@gmail.com>
+ *
+ * Original Rect/Range code by:
+ *   Lauris Kaplinski <lauris@kaplinski.com>
+ *   Nathan Hurst <njh@mail.csse.monash.edu.au>
+ *   bulia byak <buliabyak@users.sf.net>
+ *   MenTaLguY <mental@rydia.net>
+ *
+ * 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, output 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_INTERVAL_H
+#define LIB2GEOM_SEEN_INTERVAL_H
+
+#include <boost/none.hpp>
+#include <boost/operators.hpp>
+#include <2geom/coord.h>
+#include <2geom/math-utils.h>
+#include <2geom/generic-interval.h>
+#include <2geom/int-interval.h>
+
+namespace Geom {
+
+/**
+ * @brief Range of real numbers that is never empty.
+ *
+ * Intervals are closed ranges \f$[a, b]\f$, which means they include their endpoints.
+ * To use them as open ranges, you can use the interiorContains() methods.
+ *
+ * @ingroup Primitives
+ */
+class Interval
+    : public GenericInterval<Coord>
+{
+    typedef GenericInterval<Coord> Base;
+public:
+    /// @name Create intervals.
+    /// @{
+    /** @brief Create an interval that contains only zero. */
+    Interval() {}
+    /** @brief Create an interval that contains a single point. */
+    explicit Interval(Coord u) : Base(u) {}
+    /** @brief Create an interval that contains all points between @c u and @c v. */
+    Interval(Coord u, Coord v) : Base(u,v) {}
+    /** @brief Convert from integer interval */
+    Interval(IntInterval const &i) : Base(i.min(), i.max()) {}
+    Interval(Base const &b) : Base(b) {}
+
+    /** @brief Create an interval containing a range of values.
+     * The resulting interval will contain all values from the given range.
+     * The return type of iterators must be convertible to Coord. The given range
+     * must not be empty. For potentially empty ranges, see OptInterval.
+     * @param start Beginning of the range
+     * @param end   End of the range
+     * @return Interval that contains all values from [start, end). */
+    template <typename InputIterator>
+    static Interval from_range(InputIterator start, InputIterator end) {
+        Interval result = Base::from_range(start, end);
+        return result;
+    }
+    /** @brief Create an interval from a C-style array of values it should contain. */
+    static Interval from_array(Coord const *c, unsigned n) {
+        Interval result = from_range(c, c+n);
+        return result;
+    }
+    /// @}
+
+    /// @name Inspect contained values.
+    /// @{
+    /// Check whether both endpoints are finite.
+    bool isFinite() const {
+        return std::isfinite(min()) && std::isfinite(max());
+    }
+    /** @brief Map the interval [0,1] onto this one.
+     * This method simply performs 1D linear interpolation between endpoints. */
+    Coord valueAt(Coord t) const {
+        return lerp(t, min(), max());
+    }
+    /** @brief Compute a time value that maps to the given value.
+     * The supplied value does not need to be in the interval for this method to work. */
+    Coord timeAt(Coord v) const {
+        return (v - min()) / extent();
+    }
+    /// Find closest time in [0,1] that maps to the given value. */
+    Coord nearestTime(Coord v) const {
+        if (v <= min()) return 0;
+        if (v >= max()) return 1;
+        return timeAt(v);
+    }
+    /// @}
+
+    /// @name Test coordinates and other intervals for inclusion.
+    /// @{
+    /** @brief Check whether the interior of the interval includes this number.
+     * Interior means all numbers in the interval except its ends. */
+    bool interiorContains(Coord val) const { return min() < val && val < max(); }
+    /** @brief Check whether the interior of the interval includes the given interval.
+     * Interior means all numbers in the interval except its ends. */
+    bool interiorContains(Interval const &val) const { return min() < val.min() && val.max() < max(); }
+    /// Check whether the number is contained in the union of the interior and the lower boundary.
+    bool lowerContains(Coord val) const { return min() <= val && val < max(); }
+    /// Check whether the given interval is contained in the union of the interior and the lower boundary.
+    bool lowerContains(Interval const &val) const { return min() <= val.min() && val.max() < max(); }
+    /// Check whether the number is contained in the union of the interior and the upper boundary.
+    bool upperContains(Coord val) { return min() < val && val <= max(); }
+    /// Check whether the given interval is contained in the union of the interior and the upper boundary.
+    bool upperContains(Interval const &val) const { return min() < val.min() && val.max() <= max(); }
+    /** @brief Check whether the interiors of the intervals have any common elements.
+     * A single point in common is not considered an intersection. */
+    bool interiorIntersects(Interval const &val) const {
+        return std::max(min(), val.min()) < std::min(max(), val.max());
+    }
+    /// @}
+
+    /// @name Operators
+    /// @{
+    // IMPL: ScalableConcept
+    /** @brief Scale an interval */
+    Interval &operator*=(Coord s) {
+        using std::swap;
+        _b[0] *= s;
+        _b[1] *= s;
+        if(s < 0) swap(_b[0], _b[1]);
+        return *this;
+    }
+    /** @brief Scale an interval by the inverse of the specified value */
+    Interval &operator/=(Coord s) {
+        using std::swap;
+        _b[0] /= s;
+        _b[1] /= s;
+        if(s < 0) swap(_b[0], _b[1]);
+        return *this;
+    }
+    /** @brief Multiply two intervals.
+     * Product is defined as the set of points that can be obtained by multiplying
+     * any value from the second operand by any value from the first operand:
+     * \f$S = \{x \in A, y \in B: x * y\}\f$ */
+    Interval &operator*=(Interval const &o) {
+        // TODO implement properly
+        Coord mn = min(), mx = max();
+        expandTo(mn * o.min());
+        expandTo(mn * o.max());
+        expandTo(mx * o.min());
+        expandTo(mx * o.max());
+        return *this;
+    }
+    bool operator==(IntInterval const &ii) const {
+        return min() == Coord(ii.min()) && max() == Coord(ii.max());
+    }
+    bool operator==(Interval const &other) const {
+        return Base::operator==(other);
+    }
+    /// @}
+
+    /// @name Rounding to integer values
+    /// @{
+    /** @brief Return the smallest integer interval which contains this one. */
+    IntInterval roundOutwards() const {
+        IntInterval ret(floor(min()), ceil(max()));
+        return ret;
+    }
+    /** @brief Return the largest integer interval which is contained in this one. */
+    OptIntInterval roundInwards() const {
+        IntCoord u = ceil(min()), v = floor(max());
+        if (u > v) { OptIntInterval e; return e; }
+        IntInterval ret(u, v);
+        return ret;
+    }
+    /// @}
+};
+
+/**
+ * @brief Range of real numbers that can be empty.
+ * @ingroup Primitives
+ */
+class OptInterval
+    : public GenericOptInterval<Coord>
+{
+    typedef GenericOptInterval<Coord> Base;
+public:
+    using Base::Base;
+    using Base::operator==;
+    using Base::operator!=;
+
+    OptInterval(Base const &b) : Base(b) {}
+
+    /** @brief Promote from IntInterval. */
+    OptInterval(IntInterval const &i) : Base(Interval(i)) {}
+    /** @brief Promote from OptIntInterval. */
+    OptInterval(OptIntInterval const &i) : Base() {
+        if (i) *this = Interval(*i);
+    }
+};
+
+// functions required for Python bindings
+inline Interval unify(Interval const &a, Interval const &b)
+{
+    Interval r = a | b;
+    return r;
+}
+inline OptInterval intersect(Interval const &a, Interval const &b)
+{
+    OptInterval r = a & b;
+    return r;
+}
+
+} // end namespace Geom
+
+#endif //SEEN_INTERVAL_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 :