QGIS API Documentation  3.22.4-Białowieża (ce8e65e95e)
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 
225  QgsGeometry orientedMinimumBoundingBox( double &area SIP_OUT, double &angle SIP_OUT, double &width SIP_OUT, double &height SIP_OUT ) const;
226 
227  private:
228  const QgsAbstractGeometry *mGeometry = nullptr;
229 
230  mutable QString mLastError;
231 };
232 
239 class CORE_EXPORT QgsRay2D
240 {
241  public:
242 
247  QgsRay2D( const QgsPointXY &origin, QgsVector direction )
248  : origin( origin )
249  , direction( direction )
250  {}
251 
259  bool intersects( const QgsLineSegment2D &segment, QgsPointXY &intersectPoint ) const;
260 
261  private:
262 
263  QgsPointXY origin;
264  QgsVector direction;
265 };
266 
268 
269 // adapted for QGIS geometry classes from original work at https://github.com/trylock/visibility by trylock
270 
280 class CORE_EXPORT QgsLineSegmentDistanceComparer
281 {
282  public:
283 
288  explicit QgsLineSegmentDistanceComparer( const QgsPointXY &origin )
289  : mOrigin( origin )
290  {}
291 
299  bool operator()( QgsLineSegment2D ab, QgsLineSegment2D cd ) const;
300 
301  private:
302 
303  QgsPointXY mOrigin;
304 
305 };
306 
307 
308 // adapted for QGIS geometry classes from original work at https://github.com/trylock/visibility by trylock
309 
316 class CORE_EXPORT QgsClockwiseAngleComparer
317 {
318  public:
319  explicit QgsClockwiseAngleComparer( const QgsPointXY &origin )
320  : mVertex( origin )
321  {}
322 
323  bool operator()( const QgsPointXY &a, const QgsPointXY &b ) const;
324 
325  private:
326 
327  QgsPointXY mVertex;
328 
329 };
330 
332 
333 #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:125
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