QGIS API Documentation  2.14.0-Essen
qgsgeometrysimplifier.h
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1 /***************************************************************************
2  qgsgeometrysimplifier.h
3  ---------------------
4  begin : December 2013
5  copyright : (C) 2013 by Alvaro Huarte
6  email : http://wiki.osgeo.org/wiki/Alvaro_Huarte
7
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
17 #ifndef QGSGEOMETRYSIMPLIFIER_H
18 #define QGSGEOMETRYSIMPLIFIER_H
19
20 #include "qgsgeometry.h"
21
26 {
27  public:
29
31  virtual QgsGeometry* simplify( QgsGeometry* geometry ) const = 0;
33  virtual bool simplifyGeometry( QgsGeometry* geometry ) const = 0;
34
35  // MapToPixel simplification helper methods
36  public:
38  static bool isGeneralizableByDeviceBoundingBox( const QgsRectangle& envelope, float mapToPixelTol = 1.0f );
40  static bool isGeneralizableByDeviceBoundingBox( const QVector<QPointF>& points, float mapToPixelTol = 1.0f );
41 };
42
43 /***************************************************************************/
51 {
52  public:
53  QgsTopologyPreservingSimplifier( double tolerance );
55
57  virtual QgsGeometry* simplify( QgsGeometry* geometry ) const override;
59  virtual bool simplifyGeometry( QgsGeometry* geometry ) const override;
60
61  protected:
63  double mTolerance;
64
65 };
66
67 #endif // QGSGEOMETRYSIMPLIFIER_H
Implementation of GeometrySimplifier using the Douglas-Peucker algorithm.
A rectangle specified with double values.
Definition: qgsrectangle.h:35
A geometry is the spatial representation of a feature.
Definition: qgsgeometry.h:76
virtual bool simplifyGeometry(QgsGeometry *geometry) const =0
Simplifies the specified geometry.
double mTolerance
Distance tolerance for the simplification.
virtual QgsGeometry * simplify(QgsGeometry *geometry) const =0
Returns a simplified version the specified geometry.
Abstract base class for simplify geometries using a specific algorithm.