GEOS  3.11.0rc0
ConvexHull.h
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) 2005-2006 Refractions Research Inc.
8  * Copyright (C) 2001-2002 Vivid Solutions Inc.
9  *
10  * This is free software; you can redistribute and/or modify it under
11  * the terms of the GNU Lesser General Public Licence as published
12  * by the Free Software Foundation.
13  * See the COPYING file for more information.
14  *
15  **********************************************************************
16  *
17  * Last port: algorithm/ConvexHull.java r407 (JTS-1.12+)
18  *
19  **********************************************************************/
20 
21 #pragma once
22 
23 #include <geos/export.h>
24 #include <memory>
25 #include <vector>
26 #include <cassert>
27 
28 // FIXME: avoid using Cordinate:: typedefs to avoid full include
29 #include <geos/algorithm/ConvexHull.h>
30 #include <geos/geom/Coordinate.h>
31 #include <geos/geom/CoordinateSequence.h>
32 #include <geos/geom/Geometry.h>
33 #include <geos/util/UniqueCoordinateArrayFilter.h>
34 
35 #ifdef _MSC_VER
36 #pragma warning(push)
37 #pragma warning(disable: 4251) // warning C4251: needs to have dll-interface to be used by clients of class
38 #endif
39 
40 // Forward declarations
41 namespace geos {
42 namespace geom {
43 class GeometryFactory;
44 }
45 }
46 
47 namespace geos {
48 namespace algorithm { // geos::algorithm
49 
61 class GEOS_DLL ConvexHull {
62 private:
63  const geom::GeometryFactory* geomFactory;
65 
66  void
67  extractCoordinates(const geom::Geometry* geom)
68  {
69  util::UniqueCoordinateArrayFilter filter(inputPts);
70  geom->apply_ro(&filter);
71  }
72 
77  std::unique_ptr<geom::CoordinateSequence> toCoordinateSequence(geom::Coordinate::ConstVect& cv);
78 
79  void computeOctPts(const geom::Coordinate::ConstVect& src,
81 
82  bool computeOctRing(const geom::Coordinate::ConstVect& src,
84 
109  void reduce(geom::Coordinate::ConstVect& pts);
110 
112  void padArray3(geom::Coordinate::ConstVect& pts);
113 
115  void preSort(geom::Coordinate::ConstVect& pts);
116 
134  int polarCompare(const geom::Coordinate& o,
135  const geom::Coordinate& p, const geom::Coordinate& q);
136 
137  void grahamScan(const geom::Coordinate::ConstVect& c,
139 
149  std::unique_ptr<geom::Geometry> lineOrPolygon(const geom::Coordinate::ConstVect& vertices);
150 
155  void cleanRing(const geom::Coordinate::ConstVect& input,
156  geom::Coordinate::ConstVect& cleaned);
157 
162  bool isBetween(const geom::Coordinate& c1, const geom::Coordinate& c2, const geom::Coordinate& c3);
163 
164 public:
165 
169  ConvexHull(const geom::Geometry* newGeometry)
170  : geomFactory(newGeometry->getFactory())
171  {
172  extractCoordinates(newGeometry);
173  };
174 
175  ~ConvexHull() {};
176 
189  std::unique_ptr<geom::Geometry> getConvexHull();
190 };
191 
192 } // namespace geos::algorithm
193 } // namespace geos
194 
195 #ifdef _MSC_VER
196 #pragma warning(pop)
197 #endif
198 
199 
Computes the convex hull of a Geometry.
Definition: ConvexHull.h:61
std::unique_ptr< geom::Geometry > getConvexHull()
ConvexHull(const geom::Geometry *newGeometry)
Definition: ConvexHull.h:169
Coordinate is the lightweight class used to store coordinates.
Definition: Coordinate.h:58
std::vector< const Coordinate * > ConstVect
A vector of const Coordinate pointers.
Definition: Coordinate.h:69
Supplies a set of utility methods for building Geometry objects from CoordinateSequence or other Geom...
Definition: GeometryFactory.h:66
Basic implementation of Geometry, constructed and destructed by GeometryFactory.
Definition: Geometry.h:186
Basic namespace for all GEOS functionalities.
Definition: Angle.h:25