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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 Kosiński <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 constexpr Dim2 other_dimension(Dim2 d) { return Dim2(int(d) ^ 1); }
// TODO: make a smarter implementation with C++11
template <typename T>
struct D2Traits {
using D1Value = typename T::D1Value;
using D1Reference = typename T::D1Reference;
using D1ConstReference = typename T::D1ConstReference;
};
/** @brief Axis extraction functor.
* For use with things such as Boost's transform_iterator.
* @ingroup Utilities */
template <Dim2 D, typename T>
struct GetAxis {
using result_type = typename D2Traits<T>::D1Value;
using argument_type = T;
typename D2Traits<T>::D1Value operator()(T const &a) const {
return a[D];
}
};
/** @brief Floating point type used to store coordinates.
* @ingroup Primitives */
using Coord = double;
/** @brief Type used for integral coordinates.
* @ingroup Primitives */
using IntCoord = int;
/** @brief Default "acceptably small" value.
* @ingroup Primitives */
constexpr Coord EPSILON = 1e-6;
/** @brief Get a value representing infinity.
* @ingroup Primitives */
inline constexpr Coord infinity() { return std::numeric_limits<Coord>::infinity(); }
/** @brief Nearness predicate for values.
* @ingroup Primitives */
inline constexpr bool are_near(Coord a, Coord b, double eps=EPSILON) { return std::abs(a-b) <= eps; }
inline constexpr bool rel_error_bound(Coord a, Coord b, double eps=EPSILON) { return std::abs(a) <= eps*b; }
/** @brief Numerically stable linear interpolation.
* @ingroup Primitives */
inline constexpr 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 {
using PointType = D2<C>;
using IntervalType = GenericInterval<C>;
using OptIntervalType = GenericOptInterval<C>;
using RectType = GenericRect<C>;
using OptRectType = GenericOptRect<C>;
using IntervalOps =
boost::equality_comparable< IntervalType
, boost::orable< IntervalType
>>;
using RectOps =
boost::equality_comparable< RectType
, boost::orable< RectType
, boost::orable< RectType, OptRectType
>>>;
};
// NOTE: operator helpers for Rect and Interval are defined here.
// This is to avoid increasing their size through multiple inheritance.
template<>
struct CoordTraits<IntCoord> {
using PointType = IntPoint;
using IntervalType = IntInterval;
using OptIntervalType = OptIntInterval;
using RectType = IntRect;
using OptRectType = OptIntRect;
using IntervalOps =
boost::equality_comparable< IntInterval
, boost::additive< IntInterval
, boost::additive< IntInterval, IntCoord
, boost::orable< IntInterval
>>>>;
using RectOps =
boost::equality_comparable< IntRect
, boost::orable< IntRect
, boost::orable< IntRect, OptIntRect
, boost::additive< IntRect, IntPoint
>>>>;
};
template<>
struct CoordTraits<Coord> {
using PointType = Point;
using IntervalType = Interval;
using OptIntervalType = OptInterval;
using RectType = Rect;
using OptRectType = OptRect;
using IntervalOps =
boost::equality_comparable< Interval
, boost::equality_comparable< Interval, IntInterval
, boost::additive< Interval
, boost::multipliable< Interval
, boost::orable< Interval
, boost::arithmetic< Interval, Coord
>>>>>>;
using RectOps =
boost::equality_comparable< Rect
, boost::equality_comparable< Rect, IntRect
, boost::orable< Rect
, boost::orable< Rect, OptRect
, boost::additive< Rect, Point
, boost::multipliable< Rect, Affine
>>>>>>;
};
/** @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);
} // 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 :
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