GEOS  3.3.3
CascadedUnion.h
1 /**********************************************************************
2  * $Id$
3  *
4  * GEOS - Geometry Engine Open Source
5  * http://trac.osgeo.org/geos
6  *
7  * Copyright (C) 2011 Sandro Santilli <strk@keybit.net>
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.
12  * See the COPYING file for more information.
13  *
14  **********************************************************************
15  *
16  * Last port: ORIGINAL WORK, generalization of CascadedPolygonUnion
17  *
18  **********************************************************************/
19 
20 #ifndef GEOS_OP_UNION_CASCADEDUNION_H
21 #define GEOS_OP_UNION_CASCADEDUNION_H
22 
23 #include <geos/export.h>
24 
25 #include <vector>
26 #include <algorithm>
27 
28 #include "GeometryListHolder.h"
29 
30 // Forward declarations
31 namespace geos {
32  namespace geom {
33  class GeometryFactory;
34  class Geometry;
35  class Geometry;
36  class Envelope;
37  }
38  namespace index {
39  namespace strtree {
40  class ItemsList;
41  }
42  }
43 }
44 
45 namespace geos {
46 namespace operation { // geos::operation
47 namespace geounion { // geos::operation::geounion
48 
56 class GEOS_DLL CascadedUnion
57 {
58 private:
59  const std::vector<geom::Geometry*>* inputGeoms;
60  geom::GeometryFactory const* geomFactory;
61 
69  static int const STRTREE_NODE_CAPACITY = 4;
70 
71 public:
72  CascadedUnion();
73 
80  static geom::Geometry* Union(std::vector<geom::Geometry*>* geoms);
81 
89  template <class T>
90  static geom::Geometry* Union(T start, T end)
91  {
92  std::vector<geom::Geometry*> polys;
93  for (T i=start; i!=end; ++i) {
94  const geom::Geometry* p = dynamic_cast<const geom::Geometry*>(*i);
95  polys.push_back(const_cast<geom::Geometry*>(p));
96  }
97  return Union(&polys);
98  }
99 
107  CascadedUnion(const std::vector<geom::Geometry*>* geoms)
108  : inputGeoms(geoms),
109  geomFactory(NULL)
110  {}
111 
118  geom::Geometry* Union();
119 
120 private:
121  geom::Geometry* unionTree(index::strtree::ItemsList* geomTree);
122 
128  geom::Geometry* binaryUnion(GeometryListHolder* geoms);
129 
139  geom::Geometry* binaryUnion(GeometryListHolder* geoms, std::size_t start,
140  std::size_t end);
141 
149  GeometryListHolder* reduceToGeometries(index::strtree::ItemsList* geomTree);
150 
160  geom::Geometry* unionSafe(geom::Geometry* g0, geom::Geometry* g1);
161 
162  geom::Geometry* unionOptimized(geom::Geometry* g0, geom::Geometry* g1);
163 
180  geom::Geometry* unionUsingEnvelopeIntersection(geom::Geometry* g0,
181  geom::Geometry* g1, geom::Envelope const& common);
182 
183  geom::Geometry* extractByEnvelope(geom::Envelope const& env,
184  geom::Geometry* geom, std::vector<geom::Geometry*>& disjointGeoms);
185 
193  static geom::Geometry* unionActual(geom::Geometry* g0, geom::Geometry* g1);
194 };
195 
196 } // namespace geos::operation::union
197 } // namespace geos::operation
198 } // namespace geos
199 
200 #endif