QGIS API Documentation  3.26.3-Buenos Aires (65e4edfdad)
qgsalgorithmtransect.cpp
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1 /***************************************************************************
2  qgsalgorithmtransect.cpp
3  -------------------------
4  begin : October 2017
5  copyright : (C) 2017 by Loïc Bartoletti
6  email : lbartoletti at tuxfamily dot org
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 #include "qgsalgorithmtransect.h"
19 #include "qgsmultilinestring.h"
20 #include "qgslinestring.h"
21 
23 
24 QString QgsTransectAlgorithm::name() const
25 {
26  return QStringLiteral( "transect" );
27 }
28 
29 QString QgsTransectAlgorithm::displayName() const
30 {
31  return QObject::tr( "Transect" );
32 }
33 
34 QStringList QgsTransectAlgorithm::tags() const
35 {
36  return QObject::tr( "transect,station,lines,extend," ).split( ',' );
37 }
38 
39 QString QgsTransectAlgorithm::group() const
40 {
41  return QObject::tr( "Vector geometry" );
42 }
43 
44 QString QgsTransectAlgorithm::groupId() const
45 {
46  return QStringLiteral( "vectorgeometry" );
47 }
48 
49 void QgsTransectAlgorithm::initAlgorithm( const QVariantMap & )
50 {
51  addParameter( new QgsProcessingParameterFeatureSource( QStringLiteral( "INPUT" ),
52  QObject::tr( "Input layer" ), QList< int >() << QgsProcessing::TypeVectorLine ) );
53  std::unique_ptr< QgsProcessingParameterDistance > length = std::make_unique< QgsProcessingParameterDistance >( QStringLiteral( "LENGTH" ), QObject::tr( "Length of the transect" ),
54  5.0, QStringLiteral( "INPUT" ), false, 0 );
55  length->setIsDynamic( true );
56  length->setDynamicPropertyDefinition( QgsPropertyDefinition( QStringLiteral( "LENGTH" ), QObject::tr( "Length of the transect" ), QgsPropertyDefinition::DoublePositive ) );
57  length->setDynamicLayerParameterName( QStringLiteral( "INPUT" ) );
58  addParameter( length.release() );
59 
60  std::unique_ptr< QgsProcessingParameterNumber > angle = std::make_unique< QgsProcessingParameterNumber >( QStringLiteral( "ANGLE" ), QObject::tr( "Angle in degrees from the original line at the vertices" ), QgsProcessingParameterNumber::Double,
61  90.0, false, 0, 360 );
62  angle->setIsDynamic( true );
63  angle->setDynamicPropertyDefinition( QgsPropertyDefinition( QStringLiteral( "ANGLE" ), QObject::tr( "Angle in degrees" ), QgsPropertyDefinition::Double ) );
64  angle->setDynamicLayerParameterName( QStringLiteral( "INPUT" ) );
65  addParameter( angle.release() );
66 
67  addParameter( new QgsProcessingParameterEnum( QStringLiteral( "SIDE" ), QObject::tr( "Side to create the transects" ), QStringList() << QObject::tr( "Left" ) << QObject::tr( "Right" ) << QObject::tr( "Both" ), false ) );
68  addParameter( new QgsProcessingParameterFeatureSink( QStringLiteral( "OUTPUT" ), QObject::tr( "Transect" ), QgsProcessing::TypeVectorLine ) );
69 
70 }
71 
72 QString QgsTransectAlgorithm::shortHelpString() const
73 {
74 
75  return QObject::tr( "This algorithm creates transects on vertices for (multi)linestring.\n" ) +
76  QObject::tr( "A transect is a line oriented from an angle (by default perpendicular) to the input polylines (at vertices)." ) +
77  QStringLiteral( "\n\n" ) +
78  QObject::tr( "Field(s) from feature(s) are returned in the transect with these new fields:\n" ) +
79  QObject::tr( "- TR_FID: ID of the original feature\n" ) +
80  QObject::tr( "- TR_ID: ID of the transect. Each transect have an unique ID\n" ) +
81  QObject::tr( "- TR_SEGMENT: ID of the segment of the linestring\n" ) +
82  QObject::tr( "- TR_ANGLE: Angle in degrees from the original line at the vertex\n" ) +
83  QObject::tr( "- TR_LENGTH: Total length of the transect returned\n" ) +
84  QObject::tr( "- TR_ORIENT: Side of the transect (only on the left or right of the line, or both side)\n" );
85 
86 }
87 
88 QgsTransectAlgorithm *QgsTransectAlgorithm::createInstance() const
89 {
90  return new QgsTransectAlgorithm();
91 }
92 
93 QVariantMap QgsTransectAlgorithm::processAlgorithm( const QVariantMap &parameters, QgsProcessingContext &context, QgsProcessingFeedback *feedback )
94 {
95  const Side orientation = static_cast< QgsTransectAlgorithm::Side >( parameterAsInt( parameters, QStringLiteral( "SIDE" ), context ) );
96  const double angle = fabs( parameterAsDouble( parameters, QStringLiteral( "ANGLE" ), context ) );
97  const bool dynamicAngle = QgsProcessingParameters::isDynamic( parameters, QStringLiteral( "ANGLE" ) );
98  QgsProperty angleProperty;
99  if ( dynamicAngle )
100  angleProperty = parameters.value( QStringLiteral( "ANGLE" ) ).value< QgsProperty >();
101 
102  double length = parameterAsDouble( parameters, QStringLiteral( "LENGTH" ), context );
103  const bool dynamicLength = QgsProcessingParameters::isDynamic( parameters, QStringLiteral( "LENGTH" ) );
104  QgsProperty lengthProperty;
105  if ( dynamicLength )
106  lengthProperty = parameters.value( QStringLiteral( "LENGTH" ) ).value< QgsProperty >();
107 
108  if ( orientation == QgsTransectAlgorithm::Both )
109  length /= 2.0;
110 
111  std::unique_ptr< QgsFeatureSource > source( parameterAsSource( parameters, QStringLiteral( "INPUT" ), context ) );
112  if ( !source )
113  throw QgsProcessingException( invalidSourceError( parameters, QStringLiteral( "INPUT" ) ) );
114 
115  QgsExpressionContext expressionContext = createExpressionContext( parameters, context, dynamic_cast< QgsProcessingFeatureSource * >( source.get() ) );
116 
117  QgsFields fields = source->fields();
118 
119  fields.append( QgsField( QStringLiteral( "TR_FID" ), QVariant::Int, QString(), 20 ) );
120  fields.append( QgsField( QStringLiteral( "TR_ID" ), QVariant::Int, QString(), 20 ) );
121  fields.append( QgsField( QStringLiteral( "TR_SEGMENT" ), QVariant::Int, QString(), 20 ) );
122  fields.append( QgsField( QStringLiteral( "TR_ANGLE" ), QVariant::Double, QString(), 5, 2 ) );
123  fields.append( QgsField( QStringLiteral( "TR_LENGTH" ), QVariant::Double, QString(), 20, 6 ) );
124  fields.append( QgsField( QStringLiteral( "TR_ORIENT" ), QVariant::Int, QString(), 1 ) );
125 
127  if ( QgsWkbTypes::hasZ( source->wkbType() ) )
128  outputWkb = QgsWkbTypes::addZ( outputWkb );
129  if ( QgsWkbTypes::hasM( source->wkbType() ) )
130  outputWkb = QgsWkbTypes::addM( outputWkb );
131 
132  QString dest;
133  std::unique_ptr< QgsFeatureSink > sink( parameterAsSink( parameters, QStringLiteral( "OUTPUT" ), context, dest, fields,
134  outputWkb, source->sourceCrs(), QgsFeatureSink::RegeneratePrimaryKey ) );
135  if ( !sink )
136  throw QgsProcessingException( invalidSinkError( parameters, QStringLiteral( "OUTPUT" ) ) );
137 
138  QgsFeatureIterator features = source->getFeatures( );
139 
140  int current = -1;
141  int number = 0;
142  const double step = source->featureCount() > 0 ? 100.0 / source->featureCount() : 1;
143  QgsFeature feat;
144 
145 
146  while ( features.nextFeature( feat ) )
147  {
148  current++;
149  if ( feedback->isCanceled() )
150  {
151  break;
152  }
153 
154  feedback->setProgress( current * step );
155  if ( !feat.hasGeometry() )
156  continue;
157 
158  QgsGeometry inputGeometry = feat.geometry();
159 
160  if ( dynamicLength || dynamicAngle )
161  {
162  expressionContext.setFeature( feat );
163  }
164 
165  double evaluatedLength = length;
166  if ( dynamicLength )
167  evaluatedLength = lengthProperty.valueAsDouble( context.expressionContext(), length );
168  double evaluatedAngle = angle;
169  if ( dynamicAngle )
170  evaluatedAngle = angleProperty.valueAsDouble( context.expressionContext(), angle );
171 
172  inputGeometry.convertToMultiType();
173  const QgsMultiLineString *multiLine = static_cast< const QgsMultiLineString * >( inputGeometry.constGet() );
174  for ( int id = 0; id < multiLine->numGeometries(); ++id )
175  {
176  const QgsLineString *line = multiLine->lineStringN( id );
178  while ( it != line->vertices_end() )
179  {
180  const QgsVertexId vertexId = it.vertexId();
181  const int i = vertexId.vertex;
182  QgsFeature outFeat;
183  QgsAttributes attrs = feat.attributes();
184  attrs << current << number << i + 1 << evaluatedAngle <<
185  ( ( orientation == QgsTransectAlgorithm::Both ) ? evaluatedLength * 2 : evaluatedLength ) <<
186  orientation;
187  outFeat.setAttributes( attrs );
188  const double angleAtVertex = line->vertexAngle( vertexId );
189  outFeat.setGeometry( calcTransect( *it, angleAtVertex, evaluatedLength, orientation, evaluatedAngle ) );
190  if ( !sink->addFeature( outFeat, QgsFeatureSink::FastInsert ) )
191  throw QgsProcessingException( writeFeatureError( sink.get(), parameters, QStringLiteral( "OUTPUT" ) ) );
192  number++;
193  it++;
194  }
195  }
196  }
197 
198  QVariantMap outputs;
199  outputs.insert( QStringLiteral( "OUTPUT" ), dest );
200  return outputs;
201 }
202 
203 
204 QgsGeometry QgsTransectAlgorithm::calcTransect( const QgsPoint &point, const double angleAtVertex, const double length, const QgsTransectAlgorithm::Side orientation, const double angle )
205 {
206  QgsPoint pLeft; // left point of the line
207  QgsPoint pRight; // right point of the line
208 
209  QgsPolyline line;
210 
211  if ( ( orientation == QgsTransectAlgorithm::Right ) || ( orientation == QgsTransectAlgorithm::Both ) )
212  {
213  pLeft = point.project( length, angle + 180.0 / M_PI * angleAtVertex );
214  if ( orientation != QgsTransectAlgorithm::Both )
215  pRight = point;
216  }
217 
218  if ( ( orientation == QgsTransectAlgorithm::Left ) || ( orientation == QgsTransectAlgorithm::Both ) )
219  {
220  pRight = point.project( -length, angle + 180.0 / M_PI * angleAtVertex );
221  if ( orientation != QgsTransectAlgorithm::Both )
222  pLeft = point;
223  }
224 
225  line.append( pLeft );
226  line.append( pRight );
227 
228  return QgsGeometry::fromPolyline( line );
229 }
230 
QgsAbstractGeometry::vertices_end
vertex_iterator vertices_end() const
Returns STL-style iterator pointing to the imaginary vertex after the last vertex of the geometry.
Definition: qgsabstractgeometry.h:993
QgsExpressionContext
Expression contexts are used to encapsulate the parameters around which a QgsExpression should be eva...
Definition: qgsexpressioncontext.h:406
QgsFeedback::setProgress
void setProgress(double progress)
Sets the current progress for the feedback object.
Definition: qgsfeedback.h:76
QgsVertexId::vertex
int vertex
Vertex number.
Definition: qgsvertexid.h:95
QgsProcessingParameterNumber::Double
@ Double
Double/float values.
Definition: qgsprocessingparameters.h:2187
QgsProperty
A store for object properties.
Definition: qgsproperty.h:230
qgslinestring.h
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
QgsPoint
Point geometry type, with support for z-dimension and m-values.
Definition: qgspoint.h:48
QgsProcessingFeedback
Base class for providing feedback from a processing algorithm.
Definition: qgsprocessingfeedback.h:37
QgsGeometry::fromPolyline
static QgsGeometry fromPolyline(const QgsPolyline &polyline)
Creates a new LineString geometry from a list of QgsPoint points.
Definition: qgsgeometry.cpp:196
QgsWkbTypes::LineString
@ LineString
Definition: qgswkbtypes.h:73
QgsFields
Container of fields for a vector layer.
Definition: qgsfields.h:44
QgsMultiLineString
Multi line string geometry collection.
Definition: qgsmultilinestring.h:31
QgsWkbTypes::addZ
static Type addZ(Type type) SIP_HOLDGIL
Adds the z dimension to a WKB type and returns the new type.
Definition: qgswkbtypes.h:1176
QgsFeature::geometry
QgsGeometry geometry
Definition: qgsfeature.h:71
QgsFeedback::isCanceled
bool isCanceled() const SIP_HOLDGIL
Tells whether the operation has been canceled already.
Definition: qgsfeedback.h:67
QgsPropertyDefinition::Double
@ Double
Double value (including negative values)
Definition: qgsproperty.h:57
QgsProcessing::TypeVectorLine
@ TypeVectorLine
Vector line layers.
Definition: qgsprocessing.h:50
QgsProcessingParameterFeatureSource
An input feature source (such as vector layers) parameter for processing algorithms.
Definition: qgsprocessingparameters.h:3057
QgsWkbTypes::Type
Type
The WKB type describes the number of dimensions a geometry has.
Definition: qgswkbtypes.h:69
QgsFields::append
bool append(const QgsField &field, FieldOrigin origin=OriginProvider, int originIndex=-1)
Appends a field. The field must have unique name, otherwise it is rejected (returns false)
Definition: qgsfields.cpp:59
QgsLineString
Line string geometry type, with support for z-dimension and m-values.
Definition: qgslinestring.h:44
QgsProperty::value
QVariant value(const QgsExpressionContext &context, const QVariant &defaultValue=QVariant(), bool *ok=nullptr) const
Calculates the current value of the property, including any transforms which are set for the property...
Definition: qgsproperty.cpp:585
QgsPoint::project
QgsPoint project(double distance, double azimuth, double inclination=90.0) const SIP_HOLDGIL
Returns a new point which corresponds to this point projected by a specified distance with specified ...
Definition: qgspoint.cpp:735
QgsGeometryCollection::numGeometries
int numGeometries() const SIP_HOLDGIL
Returns the number of geometries within the collection.
Definition: qgsgeometrycollection.h:58
QgsProcessingParameterFeatureSink
A feature sink output for processing algorithms.
Definition: qgsprocessingparameters.h:3219
QgsWkbTypes::addM
static Type addM(Type type) SIP_HOLDGIL
Adds the m dimension to a WKB type and returns the new type.
Definition: qgswkbtypes.h:1201
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
QgsAbstractGeometry::vertices_begin
vertex_iterator vertices_begin() const
Returns STL-style iterator pointing to the first vertex of the geometry.
Definition: qgsabstractgeometry.h:980
QgsWkbTypes::hasM
static bool hasM(Type type) SIP_HOLDGIL
Tests whether a WKB type contains m values.
Definition: qgswkbtypes.h:1130
QgsPropertyDefinition
Definition for a property.
Definition: qgsproperty.h:46
QgsAbstractGeometry::vertex_iterator::vertexId
QgsVertexId vertexId() const
Returns vertex ID of the current item.
Definition: qgsabstractgeometry.cpp:447
qgsalgorithmtransect.h
QgsGeometry::constGet
const QgsAbstractGeometry * constGet() const SIP_HOLDGIL
Returns a non-modifiable (const) reference to the underlying abstract geometry primitive.
Definition: qgsgeometry.cpp:136
QgsFeatureSink::RegeneratePrimaryKey
@ RegeneratePrimaryKey
This flag indicates, that a primary key field cannot be guaranteed to be unique and the sink should i...
Definition: qgsfeaturesink.h:55
QgsFeature::attributes
QgsAttributes attributes
Definition: qgsfeature.h:69
QgsPolyline
QgsPointSequence QgsPolyline
Polyline as represented as a vector of points.
Definition: qgsgeometry.h:72
QgsAbstractGeometry::vertex_iterator
The vertex_iterator class provides STL-style iterator for vertices.
Definition: qgsabstractgeometry.h:924
QgsFeatureIterator::nextFeature
bool nextFeature(QgsFeature &f)
Definition: qgsfeatureiterator.h:399
QgsGeometry
A geometry is the spatial representation of a feature.
Definition: qgsgeometry.h:124
QgsFeature::hasGeometry
bool hasGeometry() const
Returns true if the feature has an associated geometry.
Definition: qgsfeature.cpp:230
QgsMultiLineString::lineStringN
QgsLineString * lineStringN(int index)
Returns the line string with the specified index.
Definition: qgsmultilinestring.cpp:33
QgsProcessingContext::expressionContext
QgsExpressionContext & expressionContext()
Returns the expression context.
Definition: qgsprocessingcontext.h:149
QgsGeometry::convertToMultiType
bool convertToMultiType()
Converts single type geometry into multitype geometry e.g.
Definition: qgsgeometry.cpp:1571
QgsProcessingFeatureSource
QgsFeatureSource subclass which proxies methods to an underlying QgsFeatureSource,...
Definition: qgsprocessingutils.h:577
QgsVertexId
Utility class for identifying a unique vertex within a geometry.
Definition: qgsvertexid.h:30
QgsProperty::valueAsDouble
double valueAsDouble(const QgsExpressionContext &context, double defaultValue=0.0, bool *ok=nullptr) const
Calculates the current value of the property and interprets it as a double.
Definition: qgsproperty.cpp:690
QgsWkbTypes::hasZ
static bool hasZ(Type type) SIP_HOLDGIL
Tests whether a WKB type contains the z-dimension.
Definition: qgswkbtypes.h:1080
QgsAttributes
A vector of attributes. Mostly equal to QVector<QVariant>.
Definition: qgsattributes.h:57
QgsFeature
The feature class encapsulates a single feature including its unique ID, geometry and a list of field...
Definition: qgsfeature.h:55
QgsProcessingParameterEnum
An enum based parameter for processing algorithms, allowing for selection from predefined values.
Definition: qgsprocessingparameters.h:2540
QgsFeature::setAttributes
void setAttributes(const QgsAttributes &attrs)
Sets the feature's attributes.
Definition: qgsfeature.cpp:160
QgsFeatureIterator
Wrapper for iterator of features from vector data provider or vector layer.
Definition: qgsfeatureiterator.h:289
MathUtils::angle
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
QgsProcessingException
Custom exception class for processing related exceptions.
Definition: qgsexception.h:82
QgsLineString::vertexAngle
double vertexAngle(QgsVertexId vertex) const override
Returns approximate angle at a vertex.
Definition: qgslinestring.cpp:1992
qgsmultilinestring.h
QgsFeatureSink::FastInsert
@ FastInsert
Use faster inserts, at the cost of updating the passed features to reflect changes made at the provid...
Definition: qgsfeaturesink.h:70
QgsExpressionContext::setFeature
void setFeature(const QgsFeature &feature)
Convenience function for setting a feature for the context.
Definition: qgsexpressioncontext.cpp:525
QgsPropertyDefinition::DoublePositive
@ DoublePositive
Positive double value (including 0)
Definition: qgsproperty.h:58
QgsField
Encapsulate a field in an attribute table or data source.
Definition: qgsfield.h:50