Libosmium  2.19.0
Fast and flexible C++ library for working with OpenStreetMap data
tile.hpp
Go to the documentation of this file.
1 #ifndef OSMIUM_GEOM_TILE_HPP
2 #define OSMIUM_GEOM_TILE_HPP
3 
4 /*
5 
6 This file is part of Osmium (https://osmcode.org/libosmium).
7 
8 Copyright 2013-2023 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 
38 #include <osmium/osm/location.hpp>
39 
40 #include <cassert>
41 #include <cstdint>
42 
43 namespace osmium {
44 
45  namespace geom {
46 
47  namespace detail {
48 
49  template <typename T>
50  inline constexpr const T& clamp(const T& value, const T& min, const T& max) {
51  return value < min ? min : (max < value ? max : value);
52  }
53 
54  } // namespace detail
55 
60  inline constexpr uint32_t num_tiles_in_zoom(uint32_t zoom) noexcept {
61  return 1U << zoom;
62  }
63 
68  inline constexpr double tile_extent_in_zoom(uint32_t zoom) noexcept {
69  return detail::max_coordinate_epsg3857 * 2 / num_tiles_in_zoom(zoom);
70  }
71 
77  inline constexpr uint32_t mercx_to_tilex(uint32_t zoom, double x) noexcept {
78  return static_cast<uint32_t>(detail::clamp<int32_t>(
79  static_cast<int32_t>((x + detail::max_coordinate_epsg3857) / tile_extent_in_zoom(zoom)),
80  0, num_tiles_in_zoom(zoom) - 1));
81  }
82 
88  inline constexpr uint32_t mercy_to_tiley(uint32_t zoom, double y) noexcept {
89  return static_cast<uint32_t>(detail::clamp<int32_t>(
90  static_cast<int32_t>((detail::max_coordinate_epsg3857 - y) / tile_extent_in_zoom(zoom)),
91  0, num_tiles_in_zoom(zoom) - 1));
92  }
93 
97  struct Tile {
98 
99  enum {
100  max_zoom = 30U
101  };
102 
104  uint32_t x;
105 
107  uint32_t y;
108 
110  uint32_t z;
111 
120  explicit Tile(uint32_t zoom, uint32_t tx, uint32_t ty) noexcept :
121  x(tx),
122  y(ty),
123  z(zoom) {
124  assert(zoom <= max_zoom);
125  assert(x < num_tiles_in_zoom(zoom));
126  assert(y < num_tiles_in_zoom(zoom));
127  }
128 
137  explicit Tile(uint32_t zoom, const osmium::Location& location) :
138  z(zoom) {
139  assert(zoom <= max_zoom);
140  assert(location.valid());
141  const auto coordinates = lonlat_to_mercator(location);
142  x = mercx_to_tilex(zoom, coordinates.x);
143  y = mercy_to_tiley(zoom, coordinates.y);
144  }
145 
154  explicit Tile(uint32_t zoom, const osmium::geom::Coordinates& coordinates) :
155  z(zoom) {
156  assert(zoom <= max_zoom);
157  x = mercx_to_tilex(zoom, coordinates.x);
158  y = mercy_to_tiley(zoom, coordinates.y);
159  }
160 
166  bool valid() const noexcept {
167  if (z > max_zoom) {
168  return false;
169  }
170  const auto max = num_tiles_in_zoom(z);
171  return x < max && y < max;
172  }
173 
174  }; // struct Tile
175 
177  inline bool operator==(const Tile& lhs, const Tile& rhs) noexcept {
178  return lhs.z == rhs.z && lhs.x == rhs.x && lhs.y == rhs.y;
179  }
180 
181  inline bool operator!=(const Tile& lhs, const Tile& rhs) noexcept {
182  return !(lhs == rhs);
183  }
184 
188  inline bool operator<(const Tile& lhs, const Tile& rhs) noexcept {
189  if (lhs.z < rhs.z) {
190  return true;
191  }
192  if (lhs.z > rhs.z) {
193  return false;
194  }
195  if (lhs.x < rhs.x) {
196  return true;
197  }
198  if (lhs.x > rhs.x) {
199  return false;
200  }
201  return lhs.y < rhs.y;
202  }
203 
204  } // namespace geom
205 
206 } // namespace osmium
207 
208 #endif // OSMIUM_GEOM_TILE_HPP
Definition: location.hpp:271
constexpr bool valid() const noexcept
Definition: location.hpp:352
Definition: attr.hpp:342
bool operator!=(const Coordinates &lhs, const Coordinates &rhs) noexcept
Definition: coordinates.hpp:149
constexpr uint32_t mercx_to_tilex(uint32_t zoom, double x) noexcept
Definition: tile.hpp:77
Coordinates lonlat_to_mercator(const Coordinates &c)
Definition: mercator_projection.hpp:123
constexpr double tile_extent_in_zoom(uint32_t zoom) noexcept
Definition: tile.hpp:68
bool operator==(const Coordinates &lhs, const Coordinates &rhs) noexcept
Definition: coordinates.hpp:139
bool operator<(const Tile &lhs, const Tile &rhs) noexcept
Definition: tile.hpp:188
constexpr uint32_t num_tiles_in_zoom(uint32_t zoom) noexcept
Definition: tile.hpp:60
constexpr uint32_t mercy_to_tiley(uint32_t zoom, double y) noexcept
Definition: tile.hpp:88
Namespace for everything in the Osmium library.
Definition: assembler.hpp:53
Definition: coordinates.hpp:48
double y
Definition: coordinates.hpp:51
double x
Definition: coordinates.hpp:50
Definition: tile.hpp:97
uint32_t x
x coordinate
Definition: tile.hpp:104
uint32_t z
Zoom level.
Definition: tile.hpp:110
Tile(uint32_t zoom, const osmium::geom::Coordinates &coordinates)
Definition: tile.hpp:154
Tile(uint32_t zoom, const osmium::Location &location)
Definition: tile.hpp:137
uint32_t y
y coordinate
Definition: tile.hpp:107
@ max_zoom
Definition: tile.hpp:100
Tile(uint32_t zoom, uint32_t tx, uint32_t ty) noexcept
Definition: tile.hpp:120
bool valid() const noexcept
Definition: tile.hpp:166