1 #ifndef OSMIUM_OSM_BOX_HPP
2 #define OSMIUM_OSM_BOX_HPP
3 
4 /*
5 
6 This file is part of Osmium (https://osmcode.org/libosmium).
7 
8 Copyright 2013-2021 Jochen Topf <jochen@topf.org> and others (see README).
9 
10 Boost Software License - Version 1.0 - August 17th, 2003
11 
12 Permission is hereby granted, free of charge, to any person or organization
13 obtaining a copy of the software and accompanying documentation covered by
14 this license (the "Software") to use, reproduce, display, distribute,
15 execute, and transmit the Software, and to prepare derivative works of the
16 Software, and to permit third-parties to whom the Software is furnished to
17 do so, all subject to the following:
18 
19 The copyright notices in the Software and this entire statement, including
20 the above license grant, this restriction and the following disclaimer,
21 must be included in all copies of the Software, in whole or in part, and
22 all derivative works of the Software, unless such copies or derivative
23 works are solely in the form of machine-executable object code generated by
24 a source language processor.
25 
26 THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
27 IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
28 FITNESS FOR A PARTICULAR PURPOSE, TITLE AND NON-INFRINGEMENT. IN NO EVENT
29 SHALL THE COPYRIGHT HOLDERS OR ANYONE DISTRIBUTING THE SOFTWARE BE LIABLE
30 FOR ANY DAMAGES OR OTHER LIABILITY, WHETHER IN CONTRACT, TORT OR OTHERWISE,
31 ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
32 DEALINGS IN THE SOFTWARE.
33 
34 */
35 
36 #include <osmium/osm/location.hpp>
37 
38 #include <cassert>
39 #include <iosfwd>
40 
41 namespace osmium {
42 
43     /**
44      * Bounding box. A box is defined by two locations (bottom left location
45      * and top right location) or, alternatively by four coordinates (minx,
46      * miny, maxx, and maxy). If both locations are undefined, the box is
47      * undefined, too.
48      */
49     class Box {
50 
51         osmium::Location m_bottom_left{};
52         osmium::Location m_top_right{};
53 
54     public:
55 
56         /**
57          * Create undefined Box. Use the extend() function
58          * to add actual bounds.
59          */
60         constexpr Box() noexcept = default;
61 
62         /**
63          * Create box from minimum and maximum coordinates in WGS84.
64          *
65          * @pre @code minx <= maxx && miny <= maxy @endcode
66          */
Box(double minx,double miny,double maxx,double maxy)67         Box(double minx, double miny, double maxx, double maxy) :
68             m_bottom_left(minx, miny),
69             m_top_right(maxx, maxy) {
70             assert(minx <= maxx && miny <= maxy);
71         }
72 
73         /**
74          * Create box from bottom left and top right locations.
75          *
76          * @pre Either both locations must be defined or neither.
77          * @pre If both locations are defined, the
78          *      bottom left location must actually be to the left and below
79          *      the top right location. Same coordinates for bottom/top or
80          *      left/right are also okay.
81          */
Box(const osmium::Location & bottom_left,const osmium::Location & top_right)82         Box(const osmium::Location& bottom_left, const osmium::Location& top_right) :
83             m_bottom_left(bottom_left),
84             m_top_right(top_right) {
85             assert(
86                 (!!bottom_left && !!top_right) ||
87                 (bottom_left.x() <= top_right.x() && bottom_left.y() <= top_right.y()));
88         }
89 
90         /**
91          * Extend this bounding box by the specified location. If the
92          * location is invalid, the bounding box is unchanged. If the
93          * box is undefined it will only contain the new location after
94          * this call.
95          *
96          * @param location The location we want to extend the box by.
97          * @returns A reference to this box.
98          */
extend(const Location & location)99         Box& extend(const Location& location) noexcept {
100             if (location.valid()) {
101                 if (m_bottom_left) {
102                     if (location.x() < m_bottom_left.x()) {
103                         m_bottom_left.set_x(location.x());
104                     }
105                     if (location.x() > m_top_right.x()) {
106                         m_top_right.set_x(location.x());
107                     }
108                     if (location.y() < m_bottom_left.y()) {
109                         m_bottom_left.set_y(location.y());
110                     }
111                     if (location.y() > m_top_right.y()) {
112                         m_top_right.set_y(location.y());
113                     }
114                 } else {
115                     m_bottom_left = location;
116                     m_top_right = location;
117                 }
118             }
119             return *this;
120         }
121 
122         /**
123          * Extend this bounding box by the specified box. If the
124          * specified box is undefined, the bounding box is unchanged.
125          *
126          * @param box The box to extend by.
127          * @returns A reference to this box.
128          */
extend(const Box & box)129         Box& extend(const Box& box) noexcept {
130             extend(box.bottom_left());
131             extend(box.top_right());
132             return *this;
133         }
134 
135         /**
136          * Box is defined, ie. contains defined locations.
137          */
operator bool() const138         explicit constexpr operator bool() const noexcept {
139             return bool(m_bottom_left) && bool(m_top_right);
140         }
141 
142         /**
143          * Box is valid, ie. defined and inside usual bounds
144          * (-180<=lon<=180, -90<=lat<=90).
145          */
valid() const146         constexpr bool valid() const noexcept {
147             return bottom_left().valid() && top_right().valid();
148         }
149 
150         /**
151          * Access bottom-left location.
152          */
bottom_left() const153         constexpr Location bottom_left() const noexcept {
154             return m_bottom_left;
155         }
156 
157         /**
158          * Access bottom-left location.
159          */
bottom_left()160         Location& bottom_left() noexcept {
161             return m_bottom_left;
162         }
163 
164         /**
165          * Access top-right location.
166          */
top_right() const167         constexpr Location top_right() const noexcept {
168             return m_top_right;
169         }
170 
171         /**
172          * Access top-right location.
173          */
top_right()174         Location& top_right() noexcept {
175             return m_top_right;
176         }
177 
178         /**
179          * Get left boundary.
180          *
181          * @pre @code valid() == true @encode
182          */
left() const183         double left() const noexcept {
184             assert(valid());
185             return m_bottom_left.lon_without_check();
186         }
187 
188         /**
189          * Get right boundary.
190          *
191          * @pre @code valid() == true @encode
192          */
right() const193         double right() const noexcept {
194             assert(valid());
195             return m_top_right.lon_without_check();
196         }
197 
198         /**
199          * Get top boundary.
200          *
201          * @pre @code valid() == true @encode
202          */
top() const203         double top() const noexcept {
204             assert(valid());
205             return m_top_right.lat_without_check();
206         }
207 
208         /**
209          * Get bottom boundary.
210          *
211          * @pre @code valid() == true @encode
212          */
bottom() const213         double bottom() const noexcept {
214             assert(valid());
215             return m_bottom_left.lat_without_check();
216         }
217 
218         /**
219          * Check whether the location is inside the box.
220          *
221          * @pre Location must be defined.
222          * @pre Box must be defined.
223          */
contains(const osmium::Location & location) const224         bool contains(const osmium::Location& location) const noexcept {
225             assert(bottom_left());
226             assert(top_right());
227             assert(location);
228             return location.x() >= bottom_left().x() && location.y() >= bottom_left().y() &&
229                    location.x() <= top_right().x() && location.y() <= top_right().y();
230         }
231 
232         /**
233          * Calculate size of the box in square degrees.
234          *
235          * Note that this measure isn't very useful if you want to know the
236          * real-world size of the bounding box!
237          *
238          * @throws osmium::invalid_location unless all coordinates are valid.
239          */
size() const240         double size() const {
241             return (m_top_right.lon() - m_bottom_left.lon()) *
242                    (m_top_right.lat() - m_bottom_left.lat());
243         }
244 
245     }; // class Box
246 
247     /**
248      * Boxes are equal if both locations are equal. Undefined boxes will
249      * compare equal.
250      */
operator ==(const Box & lhs,const Box & rhs)251     inline constexpr bool operator==(const Box& lhs, const Box& rhs) noexcept {
252         return lhs.bottom_left() == rhs.bottom_left() &&
253                lhs.top_right() == rhs.top_right();
254     }
255 
256     /**
257      * Output a box to a stream. The format is "(LON, LAT, LON, LAT)" or
258      * "(undefined)" if the box is undefined.
259      *
260      * @returns Reference to basic_ostream given as first parameter.
261      */
262     template <typename TChar, typename TTraits>
operator <<(std::basic_ostream<TChar,TTraits> & out,const osmium::Box & box)263     inline std::basic_ostream<TChar, TTraits>& operator<<(std::basic_ostream<TChar, TTraits>& out, const osmium::Box& box) {
264         if (box) {
265             out << '(';
266             box.bottom_left().as_string_without_check(std::ostream_iterator<char>(out));
267             out << ',';
268             box.top_right().as_string_without_check(std::ostream_iterator<char>(out));
269             out << ')';
270         } else {
271             out << "(undefined)";
272         }
273         return out;
274     }
275 
276 } // namespace osmium
277 
278 #endif // OSMIUM_OSM_BOX_HPP
279