GEOS  3.9.0dev
OffsetCurveBuilder.h
1 /**********************************************************************
2  *
3  * GEOS - Geometry Engine Open Source
4  * http://geos.osgeo.org
5  *
6  * Copyright (C) 2009-2011 Sandro Santilli <strk@kbt.io>
7  * Copyright (C) 2006-2007 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.
12  * See the COPYING file for more information.
13  *
14  **********************************************************************
15  *
16  * Last port: operation/buffer/OffsetCurveBuilder.java r378 (JTS-1.12)
17  *
18  **********************************************************************/
19 
20 #ifndef GEOS_OP_BUFFER_OFFSETCURVEBUILDER_H
21 #define GEOS_OP_BUFFER_OFFSETCURVEBUILDER_H
22 
23 #include <geos/export.h>
24 
25 #include <geos/operation/buffer/BufferParameters.h> // for composition
26 #include <geos/operation/buffer/OffsetSegmentGenerator.h>
27 
28 #include <vector>
29 #include <memory> // for unique_ptr
30 
31 #ifdef _MSC_VER
32 #pragma warning(push)
33 #pragma warning(disable: 4251) // warning C4251: needs to have dll-interface to be used by clients of class
34 #endif
35 
36 // Forward declarations
37 namespace geos {
38 namespace geom {
39 class CoordinateSequence;
40 class PrecisionModel;
41 }
42 }
43 
44 namespace geos {
45 namespace operation { // geos.operation
46 namespace buffer { // geos.operation.buffer
47 
62 class GEOS_DLL OffsetCurveBuilder {
63 public:
64 
65  /*
66  * @param nBufParams buffer parameters, this object will
67  * keep a reference to the passed parameters
68  * so caller must make sure the object is
69  * kept alive for the whole lifetime of
70  * the buffer builder.
71  */
72  OffsetCurveBuilder(const geom::PrecisionModel* newPrecisionModel,
73  const BufferParameters& nBufParams)
74  :
75  distance(0.0),
76  precisionModel(newPrecisionModel),
77  bufParams(nBufParams)
78  {}
79 
85  const BufferParameters&
87  {
88  return bufParams;
89  }
90 
103  bool isLineOffsetEmpty(double distance);
104 
117  void getLineCurve(const geom::CoordinateSequence* inputPts,
118  double distance,
119  std::vector<geom::CoordinateSequence*>& lineList);
120 
139  void getSingleSidedLineCurve(const geom::CoordinateSequence* inputPts,
140  double distance, std::vector<geom::CoordinateSequence*>& lineList,
141  bool leftSide, bool rightSide) ;
142 
153  void getRingCurve(const geom::CoordinateSequence* inputPts, int side,
154  double distance,
155  std::vector<geom::CoordinateSequence*>& lineList);
156 
157 private:
158 
159  double distance;
160 
161  const geom::PrecisionModel* precisionModel;
162 
163  const BufferParameters& bufParams;
164 
172  static const double SIMPLIFY_FACTOR; // 100.0;
173 
181  double simplifyTolerance(double bufDistance);
182 
183  void computeLineBufferCurve(const geom::CoordinateSequence& inputPts,
184  OffsetSegmentGenerator& segGen);
185 
186  void computeSingleSidedBufferCurve(const geom::CoordinateSequence& inputPts,
187  bool isRightSide,
188  OffsetSegmentGenerator& segGen);
189 
190  void computeRingBufferCurve(const geom::CoordinateSequence& inputPts,
191  int side, OffsetSegmentGenerator& segGen);
192 
193  std::unique_ptr<OffsetSegmentGenerator> getSegGen(double dist);
194 
195  void computePointCurve(const geom::Coordinate& pt,
196  OffsetSegmentGenerator& segGen);
197 
198 
199  // Declare type as noncopyable
200  OffsetCurveBuilder(const OffsetCurveBuilder& other) = delete;
201  OffsetCurveBuilder& operator=(const OffsetCurveBuilder& rhs) = delete;
202 };
203 
204 } // namespace geos::operation::buffer
205 } // namespace geos::operation
206 } // namespace geos
207 
208 #ifdef _MSC_VER
209 #pragma warning(pop)
210 #endif
211 
212 #endif // ndef GEOS_OP_BUFFER_OFFSETCURVEBUILDER_H
213 
Definition: OffsetSegmentGenerator.h:61
Coordinate is the lightweight class used to store coordinates.
Definition: Coordinate.h:60
Specifies the precision model of the Coordinate in a Geometry.
Definition: PrecisionModel.h:87
Computes the raw offset curve for a single Geometry component (ring, line or point).
Definition: OffsetCurveBuilder.h:62
const BufferParameters & getBufferParameters() const
Gets the buffer parameters being used to generate the curve.
Definition: OffsetCurveBuilder.h:86
Basic namespace for all GEOS functionalities.
Definition: IndexedNestedRingTester.h:26
Contains the parameters which describe how a buffer should be constructed.
Definition: BufferParameters.h:57
The internal representation of a list of coordinates inside a Geometry.
Definition: CoordinateSequence.h:58