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+/** @file
+ * @brief Integral and real coordinate types and some basic utilities
+ *//*
+ * Authors:
+ * Nathan Hurst <njh@mail.csse.monash.edu.au>
+ * Krzysztof KosiƄski <tweenk.pl@gmail.com>
+ * Copyright 2006-2015 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 LIB2GEOM_SEEN_COORD_H
+#define LIB2GEOM_SEEN_COORD_H
+
+#include <cmath>
+#include <limits>
+#include <string>
+#include <functional>
+#include <boost/operators.hpp>
+#include <2geom/forward.h>
+
+namespace Geom {
+
+/** @brief 2D axis enumeration (X or Y).
+ * @ingroup Primitives */
+enum Dim2 { X=0, Y=1 };
+
+/** @brief Get the other (perpendicular) dimension.
+ * @ingroup Primitives */
+inline Dim2 other_dimension(Dim2 d) { return d == Y ? X : Y; }
+
+// TODO: make a smarter implementation with C++11
+template <typename T>
+struct D2Traits {
+ typedef typename T::D1Value D1Value;
+ typedef typename T::D1Reference D1Reference;
+ typedef typename T::D1ConstReference D1ConstReference;
+};
+
+/** @brief Axis extraction functor.
+ * For use with things such as Boost's transform_iterator.
+ * @ingroup Utilities */
+template <Dim2 D, typename T>
+struct GetAxis {
+ typedef typename D2Traits<T>::D1Value result_type;
+ typedef T argument_type;
+ typename D2Traits<T>::D1Value operator()(T const &a) const {
+ return a[D];
+ }
+};
+
+/** @brief Floating point type used to store coordinates.
+ * @ingroup Primitives */
+typedef double Coord;
+
+/** @brief Type used for integral coordinates.
+ * @ingroup Primitives */
+typedef int IntCoord;
+
+/** @brief Default "acceptably small" value.
+ * @ingroup Primitives */
+const Coord EPSILON = 1e-6; //1e-18;
+
+/** @brief Get a value representing infinity.
+ * @ingroup Primitives */
+inline Coord infinity() { return std::numeric_limits<Coord>::infinity(); }
+
+/** @brief Nearness predicate for values.
+ * @ingroup Primitives */
+inline bool are_near(Coord a, Coord b, double eps=EPSILON) { return a-b <= eps && a-b >= -eps; }
+inline bool rel_error_bound(Coord a, Coord b, double eps=EPSILON) { return a <= eps*b && a >= -eps*b; }
+
+/** @brief Numerically stable linear interpolation.
+ * @ingroup Primitives */
+inline Coord lerp(Coord t, Coord a, Coord b) {
+ return (1 - t) * a + t * b;
+}
+
+/** @brief Traits class used with coordinate types.
+ * Defines point, interval and rectangle types for the given coordinate type.
+ * @ingroup Utilities */
+template <typename C>
+struct CoordTraits {
+ typedef D2<C> PointType;
+ typedef GenericInterval<C> IntervalType;
+ typedef GenericOptInterval<C> OptIntervalType;
+ typedef GenericRect<C> RectType;
+ typedef GenericOptRect<C> OptRectType;
+
+ typedef
+ boost::equality_comparable< IntervalType
+ , boost::orable< IntervalType
+ > >
+ IntervalOps;
+
+ typedef
+ boost::equality_comparable< RectType
+ , boost::orable< RectType
+ , boost::orable< RectType, OptRectType
+ > > >
+ RectOps;
+};
+
+// NOTE: operator helpers for Rect and Interval are defined here.
+// This is to avoid increasing their size through multiple inheritance.
+
+template<>
+struct CoordTraits<IntCoord> {
+ typedef IntPoint PointType;
+ typedef IntInterval IntervalType;
+ typedef OptIntInterval OptIntervalType;
+ typedef IntRect RectType;
+ typedef OptIntRect OptRectType;
+
+ typedef
+ boost::equality_comparable< IntInterval
+ , boost::additive< IntInterval
+ , boost::additive< IntInterval, IntCoord
+ , boost::orable< IntInterval
+ > > > >
+ IntervalOps;
+
+ typedef
+ boost::equality_comparable< IntRect
+ , boost::orable< IntRect
+ , boost::orable< IntRect, OptIntRect
+ , boost::additive< IntRect, IntPoint
+ > > > >
+ RectOps;
+};
+
+template<>
+struct CoordTraits<Coord> {
+ typedef Point PointType;
+ typedef Interval IntervalType;
+ typedef OptInterval OptIntervalType;
+ typedef Rect RectType;
+ typedef OptRect OptRectType;
+
+ typedef
+ boost::equality_comparable< Interval
+ , boost::equality_comparable< Interval, IntInterval
+ , boost::additive< Interval
+ , boost::multipliable< Interval
+ , boost::orable< Interval
+ , boost::arithmetic< Interval, Coord
+ > > > > > >
+ IntervalOps;
+
+ typedef
+ boost::equality_comparable< Rect
+ , boost::equality_comparable< Rect, IntRect
+ , boost::orable< Rect
+ , boost::orable< Rect, OptRect
+ , boost::additive< Rect, Point
+ , boost::multipliable< Rect, Affine
+ > > > > > >
+ RectOps;
+};
+
+/** @brief Convert coordinate to shortest possible string.
+ * @return The shortest string that parses back to the original value.
+ * @relates Coord */
+std::string format_coord_shortest(Coord x);
+
+/** @brief Convert coordinate to human-readable string.
+ * Unlike format_coord_shortest, this function will not omit a leading zero
+ * before a decimal point or use small negative exponents. The output format
+ * is similar to Javascript functions.
+ * @relates Coord */
+std::string format_coord_nice(Coord x);
+
+/** @brief Parse coordinate string.
+ * When using this function in conjunction with format_coord_shortest()
+ * or format_coord_nice(), the value is guaranteed to be preserved exactly.
+ * @relates Coord */
+Coord parse_coord(std::string const &s);
+
+} // end namespace Geom
+
+#endif // LIB2GEOM_SEEN_COORD_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 :