QGIS API Documentation  3.21.0-Master (56b4176581)
qgsinternalgeometryengine.h
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1 /***************************************************************************
2  qgsinternalgeometryengine.h - QgsInternalGeometryEngine
3 
4  ---------------------
5  begin : 13.1.2016
6  copyright : (C) 2016 by Matthias Kuhn
7  email : [email protected]
8  ***************************************************************************
9  * *
10  * This program is free software; you can redistribute it and/or modify *
11  * it under the terms of the GNU General Public License as published by *
12  * the Free Software Foundation; either version 2 of the License, or *
13  * (at your option) any later version. *
14  * *
15  ***************************************************************************/
16 #ifndef QGSINTERNALGEOMETRYENGINE_H
17 #define QGSINTERNALGEOMETRYENGINE_H
18 
19 #define SIP_NO_FILE
20 
21 #include <functional>
22 
23 #include "qgspointxy.h"
24 
25 class QgsGeometry;
27 class QgsLineString;
28 class QgsLineSegment2D;
29 class QgsFeedback;
30 
42 {
43  public:
44 
50  explicit QgsInternalGeometryEngine( const QgsGeometry &geometry );
51 
57  QString lastError() const;
58 
72  bool isAxisParallelRectangle( double maximumDeviation, bool simpleRectanglesOnly = false ) const;
73 
82  QgsGeometry extrude( double x, double y ) const;
83 
93  QgsGeometry poleOfInaccessibility( double precision, double *distanceFromBoundary = nullptr ) const;
94 
103  QgsGeometry orthogonalize( double tolerance = 1.0E-8, int maxIterations = 1000, double angleThreshold = 15.0 ) const;
104 
113  QgsGeometry densifyByCount( int extraNodesPerSegment ) const;
114 
128  QgsGeometry densifyByDistance( double distance ) const;
129 
144  QgsGeometry variableWidthBuffer( int segments, const std::function< std::unique_ptr< double[] >( const QgsLineString *line ) > &widthFunction ) const;
145 
160  QgsGeometry taperedBuffer( double startWidth, double endWidth, int segments ) const;
161 
172  QgsGeometry variableWidthBufferByM( int segments ) const;
173 
194  static QVector< QgsPointXY > randomPointsInPolygon( const QgsGeometry &polygon, int count,
195  const std::function< bool( const QgsPointXY & ) > &acceptPoint, unsigned long seed = 0, QgsFeedback *feedback = nullptr, int maxTriesPerPoint = 0 );
196 
212  QgsGeometry convertToCurves( double distanceTolerance, double angleTolerance ) const;
213 
224  QgsGeometry orientedMinimumBoundingBox( double &area SIP_OUT, double &angle SIP_OUT, double &width SIP_OUT, double &height SIP_OUT ) const;
225 
226  private:
227  const QgsAbstractGeometry *mGeometry = nullptr;
228 
229  mutable QString mLastError;
230 };
231 
238 class CORE_EXPORT QgsRay2D
239 {
240  public:
241 
246  QgsRay2D( const QgsPointXY &origin, QgsVector direction )
247  : origin( origin )
248  , direction( direction )
249  {}
250 
258  bool intersects( const QgsLineSegment2D &segment, QgsPointXY &intersectPoint ) const;
259 
260  private:
261 
262  QgsPointXY origin;
263  QgsVector direction;
264 };
265 
267 
268 // adapted for QGIS geometry classes from original work at https://github.com/trylock/visibility by trylock
269 
279 class CORE_EXPORT QgsLineSegmentDistanceComparer
280 {
281  public:
282 
287  explicit QgsLineSegmentDistanceComparer( const QgsPointXY &origin )
288  : mOrigin( origin )
289  {}
290 
298  bool operator()( QgsLineSegment2D ab, QgsLineSegment2D cd ) const;
299 
300  private:
301 
302  QgsPointXY mOrigin;
303 
304 };
305 
306 
307 // adapted for QGIS geometry classes from original work at https://github.com/trylock/visibility by trylock
308 
315 class CORE_EXPORT QgsClockwiseAngleComparer
316 {
317  public:
318  explicit QgsClockwiseAngleComparer( const QgsPointXY &origin )
319  : mVertex( origin )
320  {}
321 
322  bool operator()( const QgsPointXY &a, const QgsPointXY &b ) const;
323 
324  private:
325 
326  QgsPointXY mVertex;
327 
328 };
329 
331 
332 #endif // QGSINTERNALGEOMETRYENGINE_H
Abstract base class for all geometries.
Base class for feedback objects to be used for cancellation of something running in a worker thread.
Definition: qgsfeedback.h:45
A geometry is the spatial representation of a feature.
Definition: qgsgeometry.h:124
This class offers geometry processing methods.
QgsInternalGeometryEngine(const QgsGeometry &geometry)
The caller is responsible that the geometry is available and unchanged for the whole lifetime of this...
QgsGeometry poleOfInaccessibility(double precision, double *distanceFromBoundary=nullptr) const
Calculates the approximate pole of inaccessibility for a surface, which is the most distant internal ...
QgsGeometry variableWidthBufferByM(int segments) const
Calculates a variable width buffer using the m-values from a (multi)line geometry.
QgsGeometry extrude(double x, double y) const
Will extrude a line or (segmentized) curve by a given offset and return a polygon representation of i...
QgsGeometry orthogonalize(double tolerance=1.0E-8, int maxIterations=1000, double angleThreshold=15.0) const
Attempts to orthogonalize a line or polygon geometry by shifting vertices to make the geometries angl...
QgsGeometry variableWidthBuffer(int segments, const std::function< std::unique_ptr< double[] >(const QgsLineString *line) > &widthFunction) const
Calculates a variable width buffer for a (multi)curve geometry.
QString lastError() const
Returns an error string referring to the last error encountered.
QgsGeometry orientedMinimumBoundingBox(double &area, double &angle, double &width, double &height) const
Returns the oriented minimum bounding box for the geometry, which is the smallest (by area) rotated r...
QgsGeometry densifyByDistance(double distance) const
Densifies the geometry by adding regularly placed extra nodes inside each segment so that the maximum...
QgsGeometry taperedBuffer(double startWidth, double endWidth, int segments) const
Calculates a tapered width buffer for a (multi)curve geometry.
QgsGeometry densifyByCount(int extraNodesPerSegment) const
Densifies the geometry by adding the specified number of extra nodes within each segment of the geome...
static QVector< QgsPointXY > randomPointsInPolygon(const QgsGeometry &polygon, int count, const std::function< bool(const QgsPointXY &) > &acceptPoint, unsigned long seed=0, QgsFeedback *feedback=nullptr, int maxTriesPerPoint=0)
Returns a list of count random points generated inside a polygon geometry (if acceptPoint is specifie...
QgsGeometry convertToCurves(double distanceTolerance, double angleTolerance) const
Attempts to convert a non-curved geometry into a curved geometry type (e.g.
bool isAxisParallelRectangle(double maximumDeviation, bool simpleRectanglesOnly=false) const
Returns true if the geometry is a polygon that is almost an axis-parallel rectangle.
Represents a single 2D line segment, consisting of a 2D start and end vertex only.
Line string geometry type, with support for z-dimension and m-values.
Definition: qgslinestring.h:44
A class to represent a 2D point.
Definition: qgspointxy.h:59
A 2D ray which extends from an origin point to an infinite distance in a given direction.
QgsRay2D(const QgsPointXY &origin, QgsVector direction)
Constructor for a ray starting at the given origin and extending an infinite distance in the specifie...
A class to represent a vector.
Definition: qgsvector.h:30
double ANALYSIS_EXPORT angle(QgsPoint *p1, QgsPoint *p2, QgsPoint *p3, QgsPoint *p4)
Calculates the angle between two segments (in 2 dimension, z-values are ignored)
Definition: MathUtils.cpp:786
std::unique_ptr< GEOSGeometry, GeosDeleter > unique_ptr
Scoped GEOS pointer.
Definition: qgsgeos.h:79
#define SIP_OUT
Definition: qgis_sip.h:58
QLineF segment(int index, QRectF rect, double radius)
int precision