GEOS  3.14.0dev
BufferOp.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) 2005-2007 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: operation/buffer/BufferOp.java r378 (JTS-1.12)
18  *
19  **********************************************************************/
20 
21 #pragma once
22 
23 #include <memory> // for unique_ptr
24 #include <vector> // for vector
25 
26 #include <geos/export.h>
27 #include <geos/operation/buffer/BufferParameters.h> // for enum values
28 #include <geos/geom/Geometry.h> // to materialize Geometry
29 
30 #include <geos/util/TopologyException.h> // for composition
31 
32 #ifdef _MSC_VER
33 #pragma warning(push)
34 #pragma warning(disable: 4251) // warning C4251: needs to have dll-interface to be used by clients of class
35 #endif
36 
37 // Forward declarations
38 namespace geos {
39 namespace geom {
40 class PrecisionModel;
41 class Geometry;
42 }
43 }
44 
45 namespace geos {
46 namespace operation { // geos.operation
47 namespace buffer { // geos.operation.buffer
48 
81 class GEOS_DLL BufferOp {
82 
83 
84 private:
85 
92  static constexpr int MAX_PRECISION_DIGITS = 12;
93 
94  const geom::Geometry* argGeom;
95 
96  util::TopologyException saveException;
97 
98  double distance;
99 
100  BufferParameters bufParams;
101 
102  std::unique_ptr<geom::Geometry> resultGeometry;
103 
104  bool isInvertOrientation = false;
105 
122  static double precisionScaleFactor(const geom::Geometry* g,
123  double distance, int maxPrecisionDigits);
124 
125 
126  void computeGeometry();
127 
128  void bufferOriginalPrecision();
129 
130  void bufferReducedPrecision(int precisionDigits);
131 
132  void bufferReducedPrecision();
133 
134  void bufferFixedPrecision(const geom::PrecisionModel& fixedPM);
135 
136  static void extractPolygons(
137  geom::Geometry* poly0,
138  std::vector<std::unique_ptr<geom::Geometry>>& polys);
139 
140 public:
141 
142  enum {
146 
150 
153  CAP_SQUARE = BufferParameters::CAP_SQUARE
154  };
155 
168  static std::unique_ptr<geom::Geometry> bufferOp(
169  const geom::Geometry* g,
170  double distance,
171  int quadrantSegments = BufferParameters::DEFAULT_QUADRANT_SEGMENTS,
172  int endCapStyle = BufferParameters::CAP_ROUND);
173 
174  static std::unique_ptr<geom::Geometry> bufferOp(
175  const geom::Geometry* g,
176  double distance,
177  BufferParameters& bufParms);
178 
185  :
186  argGeom(g),
187  bufParams(),
188  resultGeometry(nullptr),
189  isInvertOrientation(false)
190  {
191  }
192 
201  BufferOp(const geom::Geometry* g, const BufferParameters& params)
202  :
203  argGeom(g),
204  bufParams(params),
205  resultGeometry(nullptr),
206  isInvertOrientation(false)
207  {
208  }
209 
218  inline void setEndCapStyle(int nEndCapStyle);
219 
225  inline void setQuadrantSegments(int nQuadrantSegments);
226 
247  inline void setSingleSided(bool isSingleSided);
248 
256  std::unique_ptr<geom::Geometry> getResultGeometry(double nDistance);
257 
275  static std::unique_ptr<geom::Geometry> bufferByZero(
276  const geom::Geometry* geom,
277  bool isBothOrientations);
278 
279 };
280 
281 // BufferOp inlines
282 void
284 {
285  bufParams.setQuadrantSegments(q);
286 }
287 
288 void
290 {
292 }
293 
294 void
295 BufferOp::setSingleSided(bool isSingleSided)
296 {
297  bufParams.setSingleSided(isSingleSided);
298 }
299 
300 } // namespace geos::operation::buffer
301 } // namespace geos::operation
302 } // namespace geos
303 
304 #ifdef _MSC_VER
305 #pragma warning(pop)
306 #endif
307 
Basic implementation of Geometry, constructed and destructed by GeometryFactory.
Definition: Geometry.h:197
Specifies the precision model of the Coordinate in a Geometry.
Definition: PrecisionModel.h:88
Computes the buffer of a geometry, for both positive and negative buffer distances.
Definition: BufferOp.h:81
void setQuadrantSegments(int nQuadrantSegments)
Sets the number of segments used to approximate a angle fillet.
Definition: BufferOp.h:283
static std::unique_ptr< geom::Geometry > bufferByZero(const geom::Geometry *geom, bool isBothOrientations)
static std::unique_ptr< geom::Geometry > bufferOp(const geom::Geometry *g, double distance, int quadrantSegments=BufferParameters::DEFAULT_QUADRANT_SEGMENTS, int endCapStyle=BufferParameters::CAP_ROUND)
Computes the buffer for a geometry for a given buffer distance and accuracy of approximation.
void setEndCapStyle(int nEndCapStyle)
Specifies the end cap style of the generated buffer.
Definition: BufferOp.h:289
void setSingleSided(bool isSingleSided)
Sets whether the computed buffer should be single-sided.
Definition: BufferOp.h:295
std::unique_ptr< geom::Geometry > getResultGeometry(double nDistance)
Returns the buffer computed for a geometry for a given buffer distance.
BufferOp(const geom::Geometry *g, const BufferParameters &params)
Initializes a buffer computation for the given geometry with the given set of parameters.
Definition: BufferOp.h:201
BufferOp(const geom::Geometry *g)
Initializes a buffer computation for the given geometry.
Definition: BufferOp.h:184
Contains the parameters which describe how a buffer should be constructed.
Definition: BufferParameters.h:56
void setEndCapStyle(EndCapStyle style)
Definition: BufferParameters.h:201
EndCapStyle
End cap styles.
Definition: BufferParameters.h:61
@ CAP_SQUARE
Specifies a square line buffer end cap style.
Definition: BufferParameters.h:70
@ CAP_ROUND
Specifies a round line buffer end cap style.
Definition: BufferParameters.h:64
@ CAP_FLAT
Specifies a flat line buffer end cap style.
Definition: BufferParameters.h:67
static const int DEFAULT_QUADRANT_SEGMENTS
The default number of facets into which to divide a fillet of 90 degrees.
Definition: BufferParameters.h:94
void setQuadrantSegments(int quadSegs)
Sets the number of line segments used to approximate an angle fillet.
void setSingleSided(bool p_isSingleSided)
Definition: BufferParameters.h:278
Indicates an invalid or inconsistent topological situation encountered during processing.
Definition: TopologyException.h:34
Basic namespace for all GEOS functionalities.
Definition: Angle.h:25