GEOS  3.9.0dev
1 /**********************************************************************
2  *
3  * GEOS - Geometry Engine Open Source
4  * http://geos.osgeo.org
5  *
6  * Copyright (C) 2011 Sandro Santilli <strk@kbt.io>
7  * Copyright (C) 2006 Refractions Research Inc.
8  *
9  * This is free software; you can redistribute and/or modify it under
10  * the terms of the GNU Lesser General Public Licence as published
11  * by the Free Software Foundation.
13  *
14  **********************************************************************
15  *
16  * Last port: operation/union/CascadedPolygonUnion.java r487 (JTS-1.12+)
17  * Includes custom code to deal with https://trac.osgeo.org/geos/ticket/837
18  *
19  **********************************************************************/
20
23
24 #include <geos/export.h>
25
26 #include <vector>
27 #include <algorithm>
28 #include <memory>
29
30 #include <geos/operation/union/GeometryListHolder.h>
31 #include <geos/operation/union/UnionStrategy.h>
32
33 // Forward declarations
34 namespace geos {
35 namespace geom {
36 class GeometryFactory;
37 class Geometry;
38 class Polygon;
39 class MultiPolygon;
40 class Envelope;
41 }
42 namespace index {
43 namespace strtree {
44 class ItemsList;
45 }
46 }
47 }
48
49 namespace geos {
50 namespace operation { // geos::operation
51 namespace geounion { // geos::operation::geounion
52
53
59 class GEOS_DLL ClassicUnionStrategy : public UnionStrategy {
60
61 public:
62
64
70  std::unique_ptr<geom::Geometry> Union(const geom::Geometry*, const geom::Geometry*) override;
71
81  bool isFloatingPrecision() const override;
82
83 private:
84
90  std::unique_ptr<geom::Geometry> unionPolygonsByBuffer(const geom::Geometry* g0, const geom::Geometry* g1);
91
92 };
93
94
95
113 private:
114  std::vector<geom::Polygon*>* inputPolys;
115  geom::GeometryFactory const* geomFactory;
116
124  static int const STRTREE_NODE_CAPACITY = 4;
125
140  static std::unique_ptr<geom::Geometry> restrictToPolygons(std::unique_ptr<geom::Geometry> g);
141
142 public:
144
151  static geom::Geometry* Union(std::vector<geom::Polygon*>* polys);
152  static geom::Geometry* Union(std::vector<geom::Polygon*>* polys, UnionStrategy* unionFun);
153
162  template <class T>
163  static geom::Geometry*
164  Union(T start, T end, UnionStrategy *unionStrategy)
165  {
166  std::vector<geom::Polygon*> polys;
167  for(T i = start; i != end; ++i) {
168  const geom::Polygon* p = dynamic_cast<const geom::Polygon*>(*i);
169  polys.push_back(const_cast<geom::Polygon*>(p));
170  }
171  return Union(&polys, unionStrategy);
172  }
173
180  static geom::Geometry* Union(const geom::MultiPolygon* polys);
181
190  : inputPolys(polys)
191  , geomFactory(nullptr)
192  , unionFunction(&defaultUnionFunction)
193  {}
194
196  : inputPolys(polys)
197  , geomFactory(nullptr)
198  , unionFunction(unionFun)
199  {}
200
207  geom::Geometry* Union();
208
209 private:
210
211  UnionStrategy* unionFunction;
212  ClassicUnionStrategy defaultUnionFunction;
213
214  geom::Geometry* unionTree(index::strtree::ItemsList* geomTree);
215
221  geom::Geometry* binaryUnion(GeometryListHolder* geoms);
222
232  geom::Geometry* binaryUnion(GeometryListHolder* geoms, std::size_t start,
233  std::size_t end);
234
242  GeometryListHolder* reduceToGeometries(index::strtree::ItemsList* geomTree);
243
253  geom::Geometry* unionSafe(geom::Geometry* g0, geom::Geometry* g1);
254
262  geom::Geometry* unionActual(geom::Geometry* g0, geom::Geometry* g1);
263 };
264
265
266
267
268
269 } // namespace geos::operation::union
270 } // namespace geos::operation
271 } // namespace geos
272
273 #endif
Creates a new instance to union the given collection of Geometrys.
Definition: MultiPolygon.h:59
Implementation of UnionStrategy that provides overlay using the first generation overlay routines...
Definition: UnionStrategy.h:40
Basic implementation of Geometry, constructed and destructed by GeometryFactory.
Definition: Geometry.h:188
Represents a linear polygon, which may include holes.
Definition: Polygon.h:64
Supplies a set of utility methods for building Geometry objects from CoordinateSequence or other Geom...
Definition: GeometryFactory.h:68
Basic namespace for all GEOS functionalities.
Definition: IndexedNestedRingTester.h:26
Provides an efficient method of unioning a collection of polygonal geometries.