Libosmium  2.15.0
Fast and flexible C++ library for working with OpenStreetMap data
geojson.hpp
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1 #ifndef OSMIUM_GEOM_GEOJSON_HPP
2 #define OSMIUM_GEOM_GEOJSON_HPP
3 
4 /*
5 
6 This file is part of Osmium (https://osmcode.org/libosmium).
7 
8 Copyright 2013-2018 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 
37 #include <osmium/geom/factory.hpp>
38 
39 #include <cassert>
40 #include <cstddef>
41 #include <string>
42 #include <utility>
43 
44 namespace osmium {
45 
46  namespace geom {
47 
48  namespace detail {
49 
50  class GeoJSONFactoryImpl {
51 
52  std::string m_str;
53  int m_precision;
54 
55  public:
56 
57  using point_type = std::string;
58  using linestring_type = std::string;
59  using polygon_type = std::string;
60  using multipolygon_type = std::string;
61  using ring_type = std::string;
62 
63  explicit GeoJSONFactoryImpl(int /*srid*/, int precision = 7) :
64  m_precision(precision) {
65  }
66 
67  /* Point */
68 
69  // { "type": "Point", "coordinates": [100.0, 0.0] }
70  point_type make_point(const osmium::geom::Coordinates& xy) const {
71  std::string str{"{\"type\":\"Point\",\"coordinates\":"};
72  xy.append_to_string(str, '[', ',', ']', m_precision);
73  str += "}";
74  return str;
75  }
76 
77  /* LineString */
78 
79  // { "type": "LineString", "coordinates": [ [100.0, 0.0], [101.0, 1.0] ] }
80  void linestring_start() {
81  m_str = "{\"type\":\"LineString\",\"coordinates\":[";
82  }
83 
84  void linestring_add_location(const osmium::geom::Coordinates& xy) {
85  xy.append_to_string(m_str, '[', ',', ']', m_precision);
86  m_str += ',';
87  }
88 
89  linestring_type linestring_finish(size_t /*num_points*/) {
90  assert(!m_str.empty());
91  std::string str;
92 
93  using std::swap;
94  swap(str, m_str);
95 
96  str.back() = ']';
97  str += "}";
98  return str;
99  }
100 
101  /* Polygon */
102  void polygon_start() {
103  m_str = "{\"type\":\"Polygon\",\"coordinates\":[[";
104  }
105 
106  void polygon_add_location(const osmium::geom::Coordinates& xy) {
107  xy.append_to_string(m_str, '[', ',', ']', m_precision);
108  m_str += ',';
109  }
110 
111  polygon_type polygon_finish(size_t /*num_points*/) {
112  assert(!m_str.empty());
113  std::string str;
114 
115  using std::swap;
116  swap(str, m_str);
117 
118  str.back() = ']';
119  str += "]}";
120  return str;
121  }
122 
123  /* MultiPolygon */
124 
125  void multipolygon_start() {
126  m_str = "{\"type\":\"MultiPolygon\",\"coordinates\":[";
127  }
128 
129  void multipolygon_polygon_start() {
130  m_str += '[';
131  }
132 
133  void multipolygon_polygon_finish() {
134  m_str += "],";
135  }
136 
137  void multipolygon_outer_ring_start() {
138  m_str += '[';
139  }
140 
141  void multipolygon_outer_ring_finish() {
142  assert(!m_str.empty());
143  m_str.back() = ']';
144  }
145 
146  void multipolygon_inner_ring_start() {
147  m_str += ",[";
148  }
149 
150  void multipolygon_inner_ring_finish() {
151  assert(!m_str.empty());
152  m_str.back() = ']';
153  }
154 
155  void multipolygon_add_location(const osmium::geom::Coordinates& xy) {
156  xy.append_to_string(m_str, '[', ',', ']', m_precision);
157  m_str += ',';
158  }
159 
160  multipolygon_type multipolygon_finish() {
161  assert(!m_str.empty());
162  std::string str;
163 
164  using std::swap;
165  swap(str, m_str);
166 
167  str.back() = ']';
168  str += "}";
169  return str;
170  }
171 
172  }; // class GeoJSONFactoryImpl
173 
174  } // namespace detail
175 
176  template <typename TProjection = IdentityProjection>
178 
179  } // namespace geom
180 
181 } // namespace osmium
182 
183 #endif // OSMIUM_GEOM_GEOJSON_HPP
Definition: factory.hpp:148
void swap(Buffer &lhs, Buffer &rhs)
Definition: buffer.hpp:880
Namespace for everything in the Osmium library.
Definition: assembler.hpp:53
Definition: attr.hpp:333
Definition: coordinates.hpp:48
void append_to_string(std::string &s, const char infix, int precision) const
Definition: coordinates.hpp:99