QGIS API Documentation  3.26.3-Buenos Aires (65e4edfdad)
qgsalgorithmdensifygeometriesbycount.cpp
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1 /***************************************************************************
2  qgsalgorithmdensifygeometries.cpp
3  ---------------------
4  begin : October 2019
5  copyright : (C) 2019 by Clemens Raffler
6  email : clemens dot raffler at gmail dot 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 
20 
22 
23 QString QgsDensifyGeometriesByCountAlgorithm::name() const
24 {
25  return QStringLiteral( "densifygeometries" );
26 }
27 
28 QString QgsDensifyGeometriesByCountAlgorithm::displayName() const
29 {
30  return QObject::tr( "Densify by count" );
31 }
32 
33 QStringList QgsDensifyGeometriesByCountAlgorithm::tags() const
34 {
35  return QObject::tr( "add,vertex,vertices,points,nodes" ).split( ',' );
36 }
37 
38 QString QgsDensifyGeometriesByCountAlgorithm::group() const
39 {
40  return QObject::tr( "Vector geometry" );
41 }
42 
43 QString QgsDensifyGeometriesByCountAlgorithm::groupId() const
44 {
45  return QStringLiteral( "vectorgeometry" );
46 }
47 
48 QString QgsDensifyGeometriesByCountAlgorithm::shortHelpString() const
49 {
50  return QObject::tr( "This algorithm takes a polygon or line layer "
51  "and generates a new one in which the geometries "
52  "have a larger number of vertices than the "
53  "original one.\n\n If the geometries have z or m values "
54  "present then these will be linearly interpolated "
55  "at the added nodes.\n\n The number of new vertices to "
56  "add to each feature geometry is specified "
57  "as an input parameter." );
58 }
59 
60 QString QgsDensifyGeometriesByCountAlgorithm::shortDescription() const
61 {
62  return QObject::tr( "Creates a densified version of geometries." );
63 }
64 
65 QgsDensifyGeometriesByCountAlgorithm *QgsDensifyGeometriesByCountAlgorithm::createInstance() const
66 {
67  return new QgsDensifyGeometriesByCountAlgorithm;
68 
69 }
70 
71 QList<int> QgsDensifyGeometriesByCountAlgorithm::inputLayerTypes() const
72 {
74 }
75 
76 void QgsDensifyGeometriesByCountAlgorithm::initParameters( const QVariantMap &configuration )
77 {
78  Q_UNUSED( configuration )
79  std::unique_ptr<QgsProcessingParameterNumber> verticesCnt = std::make_unique<QgsProcessingParameterNumber>( QStringLiteral( "VERTICES" ),
80  QObject::tr( "Number of vertices to add" ),
82  1, false, 1, 10000000 );
83  verticesCnt->setIsDynamic( true );
84  verticesCnt->setDynamicPropertyDefinition( QgsPropertyDefinition( QStringLiteral( "VerticesCount" ), QObject::tr( "Vertices count" ), QgsPropertyDefinition::IntegerPositive ) );
85  verticesCnt->setDynamicLayerParameterName( QStringLiteral( "INPUT" ) );
86  addParameter( verticesCnt.release() );
87 }
88 
89 QString QgsDensifyGeometriesByCountAlgorithm::outputName() const
90 {
91  return QObject::tr( "Densified" );
92 }
93 
94 bool QgsDensifyGeometriesByCountAlgorithm::prepareAlgorithm( const QVariantMap &parameters, QgsProcessingContext &context, QgsProcessingFeedback *feedback )
95 {
96  Q_UNUSED( feedback )
97  mVerticesCnt = parameterAsInt( parameters, QStringLiteral( "VERTICES" ), context );
98 
99  mDynamicVerticesCnt = QgsProcessingParameters::isDynamic( parameters, QStringLiteral( "VERTICES" ) );
100  if ( mDynamicVerticesCnt )
101  mVerticesCntProperty = parameters.value( QStringLiteral( "VERTICES" ) ).value< QgsProperty >();
102 
103  return true;
104 }
105 
106 QgsFeatureList QgsDensifyGeometriesByCountAlgorithm::processFeature( const QgsFeature &feature, QgsProcessingContext &context, QgsProcessingFeedback *feedback )
107 {
108  Q_UNUSED( context )
109  Q_UNUSED( feedback )
110 
111  QgsFeature densifiedFeature = feature;
112 
113  if ( feature.hasGeometry() )
114  {
115  int verticesCnt = mVerticesCnt;
116  if ( mDynamicVerticesCnt )
117  verticesCnt = mVerticesCntProperty.valueAsInt( context.expressionContext(), verticesCnt );
118 
119  if ( verticesCnt > 0 )
120  densifiedFeature.setGeometry( feature.geometry().densifyByCount( verticesCnt ) );
121  }
122 
123  return QgsFeatureList() << densifiedFeature;
124 }
125 
126 
127 
QgsProperty
A store for object properties.
Definition: qgsproperty.h:230
QgsProcessingParameters::isDynamic
static bool isDynamic(const QVariantMap &parameters, const QString &name)
Returns true if the parameter with matching name is a dynamic parameter, and must be evaluated once f...
Definition: qgsprocessingparameters.cpp:114
QgsProcessingFeedback
Base class for providing feedback from a processing algorithm.
Definition: qgsprocessingfeedback.h:37
QgsProcessing::TypeVectorPolygon
@ TypeVectorPolygon
Vector polygon layers.
Definition: qgsprocessing.h:51
QgsFeature::geometry
QgsGeometry geometry
Definition: qgsfeature.h:71
QgsProcessing::TypeVectorLine
@ TypeVectorLine
Vector line layers.
Definition: qgsprocessing.h:50
qgsalgorithmdensifygeometriesbycount.h
QgsGeometry::densifyByCount
QgsGeometry densifyByCount(int extraNodesPerSegment) const
Returns a copy of the geometry which has been densified by adding the specified number of extra nodes...
Definition: qgsgeometry.cpp:2263
QgsFeature::setGeometry
void setGeometry(const QgsGeometry &geometry)
Set the feature's geometry.
Definition: qgsfeature.cpp:170
QgsProcessingContext
Contains information about the context in which a processing algorithm is executed.
Definition: qgsprocessingcontext.h:46
QgsFeatureList
QList< QgsFeature > QgsFeatureList
Definition: qgsfeature.h:882
QgsPropertyDefinition
Definition for a property.
Definition: qgsproperty.h:46
QgsProcessingParameterNumber::Integer
@ Integer
Integer values.
Definition: qgsprocessingparameters.h:2186
QgsPropertyDefinition::IntegerPositive
@ IntegerPositive
Positive integer values (including 0)
Definition: qgsproperty.h:55
QgsFeature::hasGeometry
bool hasGeometry() const
Returns true if the feature has an associated geometry.
Definition: qgsfeature.cpp:230
QgsProcessingContext::expressionContext
QgsExpressionContext & expressionContext()
Returns the expression context.
Definition: qgsprocessingcontext.h:149
QgsFeature
The feature class encapsulates a single feature including its unique ID, geometry and a list of field...
Definition: qgsfeature.h:55