GEOS  3.9.0dev
OverlapUnion.h
1 /**********************************************************************
2  *
3  * GEOS - Geometry Engine Open Source
4  * http://trac.osgeo.org/geos
5  *
6  * Copyright (C) 2011 Sandro Santilli <strk@kbt.io>
7  *
8  * This is free software; you can redistribute and/or modify it under
9  * the terms of the GNU Lesser General Public Licence as published
10  * by the Free Software Foundation.
11  * See the COPYING file for more information.
12  *
13  **********************************************************************
14  *
15  * Last port: ORIGINAL WORK, generalization of CascadedPolygonUnion
16  *
17  **********************************************************************/
18 
19 #ifndef GEOS_OP_UNION_OVERLAPUNION_H
20 #define GEOS_OP_UNION_OVERLAPUNION_H
21 
22 #include <geos/export.h>
23 
24 #include <vector>
25 #include <algorithm>
26 #include <unordered_set>
27 
28 #include <geos/geom/Geometry.h>
29 
30 // Forward declarations
31 namespace geos {
32 namespace geom {
33 class Envelope;
34 class LineSegment;
35 }
36 }
37 
38 namespace geos {
39 namespace operation { // geos::operation
40 namespace geounion { // geos::operation::geounion
41 
91 class GEOS_DLL OverlapUnion {
92 
93 public:
94 
95  OverlapUnion(const geom::Geometry* p_g0, const geom::Geometry* p_g1)
96  : g0(p_g0), g1(p_g1)
97  {
98  geomFactory = g0->getFactory();
99  isUnionSafe = false;
100  };
101 
102  std::unique_ptr<geom::Geometry> doUnion();
103 
104 private:
105 
106  const geom::GeometryFactory* geomFactory;
107  const geom::Geometry* g0;
108  const geom::Geometry* g1;
109  bool isUnionSafe;
110 
111  geom::Envelope overlapEnvelope(const geom::Geometry* geom0, const geom::Geometry* geom1);
112  std::unique_ptr<geom::Geometry> extractByEnvelope(const geom::Envelope& env, const geom::Geometry* geom, std::vector<std::unique_ptr<geom::Geometry>>& disjointGeoms);
113  std::unique_ptr<geom::Geometry> combine(std::unique_ptr<geom::Geometry>& unionGeom, std::vector<std::unique_ptr<geom::Geometry>>& disjointPolys);
114  std::unique_ptr<geom::Geometry> unionFull(const geom::Geometry* geom0, const geom::Geometry* geom1);
115  std::unique_ptr<geom::Geometry> unionBuffer(const geom::Geometry* geom0, const geom::Geometry* geom1);
116  bool isBorderSegmentsSame(const geom::Geometry* result, const geom::Envelope& env);
117  bool isEqual(std::vector<geom::LineSegment>& segs0, std::vector<geom::LineSegment>& segs1);
118  std::vector<geom::LineSegment> extractBorderSegments(const geom::Geometry* geom0, const geom::Geometry* geom1, const geom::Envelope& env);
119  void extractBorderSegments(const geom::Geometry* geom, const geom::Envelope& penv, std::vector<geom::LineSegment>& psegs);
120 
121 };
122 
123 } // namespace geos::operation::union
124 } // namespace geos::operation
125 } // namespace geos
126 
127 #endif
An Envelope defines a rectangulare region of the 2D coordinate plane.
Definition: Envelope.h:58
Basic implementation of Geometry, constructed and destructed by GeometryFactory.
Definition: Geometry.h:188
Unions MultiPolygons efficiently by using full topological union only for polygons which may overlap ...
Definition: OverlapUnion.h:91
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