QGIS API Documentation  2.9.0-Master
qgsgeometryanalyzer.h
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1 /***************************************************************************
2  qgsgeometryanalyzer.h - QGIS Tools for vector geometry analysis
3  -------------------
4  begin : 19 March 2009
5  copyright : (C) Carson Farmer
6  email : carson.farmer@gmail.com
7  ***************************************************************************/
8 
9 /***************************************************************************
10  * *
11  * This program is free software; you can redistribute it and/or modify *
12  * it under the terms of the GNU General Public License as published by *
13  * the Free Software Foundation; either version 2 of the License, or *
14  * (at your option) any later version. *
15  * *
16  ***************************************************************************/
17 
18 #ifndef QGSGEOMETRYANALYZERH
19 #define QGSGEOMETRYANALYZERH
20 
21 #include "qgsvectorlayer.h"
22 #include "qgsfield.h"
23 #include "qgsfeature.h"
24 #include "qgsgeometry.h"
25 #include "qgsdistancearea.h"
26 
28 class QProgressDialog;
29 
30 
35 class ANALYSIS_EXPORT QgsGeometryAnalyzer
36 {
37  public:
38 
47  bool simplify( QgsVectorLayer* layer, const QString& shapefileName, double tolerance,
48  bool onlySelectedFeatures = false, QProgressDialog* p = 0 );
49 
57  bool centroids( QgsVectorLayer* layer, const QString& shapefileName,
58  bool onlySelectedFeatures = false, QProgressDialog* p = 0 );
59 
66  bool extent( QgsVectorLayer* layer, const QString& shapefileName, bool onlySelectedFeatures = false, QProgressDialog* p = 0 );
67 
77  bool buffer( QgsVectorLayer* layer, const QString& shapefileName, double bufferDistance,
78  bool onlySelectedFeatures = false, bool dissolve = false, int bufferDistanceField = -1, QProgressDialog* p = 0 );
79 
88  bool convexHull( QgsVectorLayer* layer, const QString& shapefileName, bool onlySelectedFeatures = false,
89  int uniqueIdField = -1, QProgressDialog* p = 0 );
90 
99  bool dissolve( QgsVectorLayer* layer, const QString& shapefileName, bool onlySelectedFeatures = false,
100  int uniqueIdField = -1, QProgressDialog* p = 0 );
101 
119  bool eventLayer( QgsVectorLayer* lineLayer, QgsVectorLayer* eventLayer, int lineField, int eventField, QgsFeatureIds &unlocatedFeatureIds, const QString& outputLayer,
120  const QString& outputFormat, int locationField1, int locationField2 = -1, int offsetField = -1, double offsetScale = 1.0,
121  bool forceSingleGeometry = false, QgsVectorDataProvider* memoryProvider = 0, QProgressDialog* p = 0 );
122 
124  QgsGeometry* locateBetweenMeasures( double fromMeasure, double toMeasure, const QgsGeometry *lineGeom );
127  QgsGeometry* locateAlongMeasure( double measure, const QgsGeometry* lineGeom );
128 
129  private:
130 
131  QList<double> simpleMeasure( QgsGeometry* geometry );
132  double perimeterMeasure( QgsGeometry* geometry, QgsDistanceArea& measure );
134  void simplifyFeature( QgsFeature& f, QgsVectorFileWriter* vfw, double tolerance );
136  void centroidFeature( QgsFeature& f, QgsVectorFileWriter* vfw );
138  void bufferFeature( QgsFeature& f, int nProcessedFeatures, QgsVectorFileWriter* vfw, bool dissolve, QgsGeometry** dissolveGeometry,
139  double bufferDistance, int bufferDistanceField );
141  void convexFeature( QgsFeature& f, int nProcessedFeatures, QgsGeometry** dissolveGeometry );
143  void dissolveFeature( QgsFeature& f, int nProcessedFeatures, QgsGeometry** dissolveGeometry );
144 
145  //helper functions for event layer
146  void addEventLayerFeature( QgsFeature& feature, QgsGeometry* geom, QgsGeometry* lineGeom, QgsVectorFileWriter* fileWriter, QgsFeatureList& memoryFeatures, int offsetField = -1, double offsetScale = 1.0,
147  bool forceSingleType = false );
152  bool createOffsetGeometry( QgsGeometry* geom, QgsGeometry* lineGeom, double offset );
153  QgsPoint createPointOffset( double x, double y, double dist, QgsGeometry* lineGeom ) const;
154  const unsigned char* locateBetweenWkbString( const unsigned char* ptr, QgsMultiPolyline& result, double fromMeasure, double toMeasure );
155  const unsigned char* locateAlongWkbString( const unsigned char* ptr, QgsMultiPoint& result, double measure );
156  static bool clipSegmentByRange( double x1, double y1, double m1, double x2, double y2, double m2, double range1, double range2, QgsPoint& pt1, QgsPoint& pt2, bool& secondPointClipped );
157  static void locateAlongSegment( double x1, double y1, double m1, double x2, double y2, double m2, double measure, bool& pt1Ok, QgsPoint& pt1, bool& pt2Ok, QgsPoint& pt2 );
158 };
159 #endif //QGSVECTORANALYZER
QSet< QgsFeatureId > QgsFeatureIds
Definition: qgsfeature.h:365
QList< QgsFeature > QgsFeatureList
Definition: qgsfeature.h:370
A convenience class for writing vector files to disk.
The feature class encapsulates a single feature including its id, geometry and a list of field/values...
Definition: qgsfeature.h:119
The QGis class provides vector geometry analysis functions.
A class to represent a point.
Definition: qgspoint.h:63
General purpose distance and area calculator.
int convexHull(int *id, const double *const x, const double *const y, int n)
This is the base class for vector data providers.
Represents a vector layer which manages a vector based data sets.