summaryrefslogtreecommitdiffstats
path: root/src/3rdparty/2geom/include/2geom/coord.h
blob: 9cc220db7423f582e57268635e57e1c96817d5d7 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
/** @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 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 :