QGIS API Documentation  3.8.0-Zanzibar (11aff65)
qgsgeometryanglecheck.cpp
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1 /***************************************************************************
2  qgsgeometryanglecheck.cpp
3  ---------------------
4  begin : September 2015
5  copyright : (C) 2014 by Sandro Mani / Sourcepole AG
6  email : smani at sourcepole dot ch
7  ***************************************************************************
8  * *
9  * This program is free software; you can redistribute it and/or modify *
10  * it under the terms of the GNU General Public License as published by *
11  * the Free Software Foundation; either version 2 of the License, or *
12  * (at your option) any later version. *
13  * *
14  ***************************************************************************/
15 
17 #include "qgsgeometryanglecheck.h"
18 #include "qgsgeometryutils.h"
19 #include "qgsfeaturepool.h"
20 #include "qgsgeometrycheckerror.h"
21 
22 QList<QgsWkbTypes::GeometryType> QgsGeometryAngleCheck::compatibleGeometryTypes() const
23 {
25 }
26 
27 void QgsGeometryAngleCheck::collectErrors( const QMap<QString, QgsFeaturePool *> &featurePools, QList<QgsGeometryCheckError *> &errors, QStringList &messages, QgsFeedback *feedback, const LayerFeatureIds &ids ) const
28 {
29  Q_UNUSED( messages )
30  QMap<QString, QgsFeatureIds> featureIds = ids.isEmpty() ? allLayerFeatureIds( featurePools ) : ids.toMap();
31  QgsGeometryCheckerUtils::LayerFeatures layerFeatures( featurePools, featureIds, compatibleGeometryTypes(), feedback, context() );
32  for ( const QgsGeometryCheckerUtils::LayerFeature &layerFeature : layerFeatures )
33  {
34  const QgsAbstractGeometry *geom = layerFeature.geometry().constGet();
35  for ( int iPart = 0, nParts = geom->partCount(); iPart < nParts; ++iPart )
36  {
37  for ( int iRing = 0, nRings = geom->ringCount( iPart ); iRing < nRings; ++iRing )
38  {
39  bool closed = false;
40  int nVerts = QgsGeometryCheckerUtils::polyLineSize( geom, iPart, iRing, &closed );
41  // Less than three points, no angles to check
42  if ( nVerts < 3 )
43  {
44  continue;
45  }
46  for ( int iVert = !closed; iVert < nVerts - !closed; ++iVert )
47  {
48  const QgsPoint &p1 = geom->vertexAt( QgsVertexId( iPart, iRing, ( iVert - 1 + nVerts ) % nVerts ) );
49  const QgsPoint &p2 = geom->vertexAt( QgsVertexId( iPart, iRing, iVert ) );
50  const QgsPoint &p3 = geom->vertexAt( QgsVertexId( iPart, iRing, ( iVert + 1 ) % nVerts ) );
51  QgsVector v21, v23;
52  try
53  {
54  v21 = QgsVector( p1.x() - p2.x(), p1.y() - p2.y() ).normalized();
55  v23 = QgsVector( p3.x() - p2.x(), p3.y() - p2.y() ).normalized();
56  }
57  catch ( const QgsException & )
58  {
59  // Zero length vectors
60  continue;
61  }
62 
63  double angle = std::acos( v21 * v23 ) / M_PI * 180.0;
64  if ( angle < mMinAngle )
65  {
66  errors.append( new QgsGeometryCheckError( this, layerFeature, p2, QgsVertexId( iPart, iRing, iVert ), angle ) );
67  }
68  }
69  }
70  }
71  }
72 }
73 
74 void QgsGeometryAngleCheck::fixError( const QMap<QString, QgsFeaturePool *> &featurePools, QgsGeometryCheckError *error, int method, const QMap<QString, int> & /*mergeAttributeIndices*/, Changes &changes ) const
75 {
76  QgsFeaturePool *featurePool = featurePools[ error->layerId() ];
77  QgsFeature feature;
78  if ( !featurePool->getFeature( error->featureId(), feature ) )
79  {
80  error->setObsolete();
81  return;
82  }
83  QgsGeometry featureGeometry = feature.geometry();
84  QgsAbstractGeometry *geometry = featureGeometry.get();
85  QgsVertexId vidx = error->vidx();
86 
87  // Check if point still exists
88  if ( !vidx.isValid( geometry ) )
89  {
90  error->setObsolete();
91  return;
92  }
93 
94  // Check if error still applies
95  int n = QgsGeometryCheckerUtils::polyLineSize( geometry, vidx.part, vidx.ring );
96  if ( n == 0 )
97  {
98  error->setObsolete();
99  return;
100  }
101  const QgsPoint &p1 = geometry->vertexAt( QgsVertexId( vidx.part, vidx.ring, ( vidx.vertex - 1 + n ) % n ) );
102  const QgsPoint &p2 = geometry->vertexAt( vidx );
103  const QgsPoint &p3 = geometry->vertexAt( QgsVertexId( vidx.part, vidx.ring, ( vidx.vertex + 1 ) % n ) );
104  QgsVector v21, v23;
105  try
106  {
107  v21 = QgsVector( p1.x() - p2.x(), p1.y() - p2.y() ).normalized();
108  v23 = QgsVector( p3.x() - p2.x(), p3.y() - p2.y() ).normalized();
109  }
110  catch ( const QgsException & )
111  {
112  error->setObsolete();
113  return;
114  }
115  double angle = std::acos( v21 * v23 ) / M_PI * 180.0;
116  if ( angle >= mMinAngle )
117  {
118  error->setObsolete();
119  return;
120  }
121 
122  // Fix error
123  if ( method == NoChange )
124  {
125  error->setFixed( method );
126  }
127  else if ( method == DeleteNode )
128  {
129  if ( !QgsGeometryCheckerUtils::canDeleteVertex( geometry, vidx.part, vidx.ring ) )
130  {
131  error->setFixFailed( tr( "Resulting geometry is degenerate" ) );
132  }
133  else if ( !geometry->deleteVertex( error->vidx() ) )
134  {
135  error->setFixFailed( tr( "Failed to delete vertex" ) );
136  }
137  else
138  {
139  changes[error->layerId()][error->featureId()].append( Change( ChangeNode, ChangeRemoved, vidx ) );
140  // Avoid duplicate nodes as result of deleting spike vertex
142  QgsGeometryCheckerUtils::canDeleteVertex( geometry, vidx.part, vidx.ring ) &&
143  geometry->deleteVertex( error->vidx() ) ) // error->vidx points to p3 after removing p2
144  {
145  changes[error->layerId()][error->featureId()].append( Change( ChangeNode, ChangeRemoved, QgsVertexId( vidx.part, vidx.ring, ( vidx.vertex + 1 ) % n ) ) );
146  }
147  feature.setGeometry( featureGeometry );
148  featurePool->updateFeature( feature );
149  error->setFixed( method );
150  }
151  }
152  else
153  {
154  error->setFixFailed( tr( "Unknown method" ) );
155  }
156 }
157 
159 {
160  static QStringList methods = QStringList() << tr( "Delete node with small angle" ) << tr( "No action" );
161  return methods;
162 }
163 
165 {
166  return factoryId();
167 }
168 
170 {
171  return tr( "Minimal angle" );
172 }
173 
175 {
176  return factoryDescription();
177 }
178 
180 {
181  return factoryCheckType();
182 }
183 
185 {
187 }
188 
190 {
191  return factoryCompatibleGeometryTypes().contains( layer->geometryType() );
192 }
193 
195 {
196  return QStringLiteral( "QgsGeometryAngleCheck" );
197 }
198 
200 {
202 }
double y
Definition: qgspoint.h:42
static QList< QgsWkbTypes::GeometryType > factoryCompatibleGeometryTypes()
void collectErrors(const QMap< QString, QgsFeaturePool *> &featurePools, QList< QgsGeometryCheckError *> &errors, QStringList &messages, QgsFeedback *feedback, const LayerFeatureIds &ids=LayerFeatureIds()) const override
The main worker method.
virtual bool deleteVertex(QgsVertexId position)=0
Deletes a vertex within the geometry.
bool isValid() const
Returns true if the vertex id is valid.
QString id() const override
Returns an id for this check.
QMap< QString, QgsFeatureIds > toMap() const
Contains a set of layers and feature ids in those layers to pass to a geometry check.
CheckType
The type of a check.
static int polyLineSize(const QgsAbstractGeometry *geom, int iPart, int iRing, bool *isClosed=nullptr)
Returns the number of points in a polyline, accounting for duplicate start and end point if the polyl...
QgsWkbTypes::GeometryType geometryType() const
Returns point, line or polygon.
A geometry is the spatial representation of a feature.
Definition: qgsgeometry.h:111
void setObsolete()
Set the error status to obsolete.
The feature class encapsulates a single feature including its id, geometry and a list of field/values...
Definition: qgsfeature.h:55
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
virtual void updateFeature(QgsFeature &feature)=0
Updates a feature in this pool.
void setFixFailed(const QString &reason)
Set the error status to failed and specify the reason for failure.
QStringList resolutionMethods() const override
Returns a list of descriptions for available resolutions for errors.
Base class for feedback objects to be used for cancellation of something running in a worker thread...
Definition: qgsfeedback.h:44
Something has been removed.
static QgsGeometryCheck::CheckType factoryCheckType()
Utility class for identifying a unique vertex within a geometry.
bool getFeature(QgsFeatureId id, QgsFeature &feature)
Retrieves the feature with the specified id into feature.
A layer feature combination to uniquely identify and access a feature in a set of layers...
virtual int ringCount(int part=0) const =0
Returns the number of rings of which this geometry is built.
Abstract base class for all geometries.
QMap< QString, QgsFeatureIds > allLayerFeatureIds(const QMap< QString, QgsFeaturePool *> &featurePools) const
Returns all layers and feature ids.
const QString & layerId() const
The id of the layer on which this error has been detected.
const double tolerance
The tolerance to allow for in geometry checks.
const QgsGeometryCheckContext * mContext
Point geometry type, with support for z-dimension and m-values.
Definition: qgspoint.h:37
A list of layers and feature ids for each of these layers.
A class to represent a vector.
Definition: qgsvector.h:29
QgsAbstractGeometry * get()
Returns a modifiable (non-const) reference to the underlying abstract geometry primitive.
static bool canDeleteVertex(const QgsAbstractGeometry *geom, int iPart, int iRing)
static QString factoryDescription()
static double sqrDistance2D(const QgsPoint &pt1, const QgsPoint &pt2)
Returns the squared 2D distance between two points.
QMap< QString, QMap< QgsFeatureId, QList< QgsGeometryCheck::Change > > > Changes
A collection of changes.
A feature pool is based on a vector layer and caches features.
Descripts a change to fix a geometry.
void setFixed(int method)
Set the status to fixed and specify the method that has been used to fix the error.
void fixError(const QMap< QString, QgsFeaturePool *> &featurePools, QgsGeometryCheckError *error, int method, const QMap< QString, int > &mergeAttributeIndices, Changes &changes) const override
Fix the error error with the specified method.
void setGeometry(const QgsGeometry &geometry)
Set the feature&#39;s geometry.
Definition: qgsfeature.cpp:137
static bool factoryIsCompatible(QgsVectorLayer *layer)
QgsFeatureId featureId() const
The id of the feature on which this error has been detected.
QgsGeometry geometry
Definition: qgsfeature.h:67
const QgsGeometryCheckContext * context() const
Returns the context.
This represents an error reported by a geometry check.
This change happens on node level.
virtual QgsPoint vertexAt(QgsVertexId id) const =0
Returns the point corresponding to a specified vertex id.
Represents a vector layer which manages a vector based data sets.
QgsGeometryCheck::CheckType checkType() const override
Returns the check type.
const QgsVertexId & vidx() const
The id of the affected vertex.
QString description() const override
Returns a human readable description for this check.
Defines a QGIS exception class.
Definition: qgsexception.h:34
QList< QgsWkbTypes::GeometryType > compatibleGeometryTypes() const override
A list of geometry types for which this check can be performed.
virtual int partCount() const =0
Returns count of parts contained in the geometry.
The check controls individual nodes.
double x
Definition: qgspoint.h:41