25static const QString INPUT = QStringLiteral(
"INPUT" );
26static const QString POINTS_NUMBER = QStringLiteral(
"POINTS_NUMBER" );
27static const QString MIN_DISTANCE_GLOBAL = QStringLiteral(
"MIN_DISTANCE_GLOBAL" );
28static const QString MIN_DISTANCE = QStringLiteral(
"MIN_DISTANCE" );
29static const QString MAX_TRIES_PER_POINT = QStringLiteral(
"MAX_TRIES_PER_POINT" );
30static const QString SEED = QStringLiteral(
"SEED" );
31static const QString INCLUDE_POLYGON_ATTRIBUTES = QStringLiteral(
"INCLUDE_POLYGON_ATTRIBUTES" );
32static const QString OUTPUT = QStringLiteral(
"OUTPUT" );
33static const QString OUTPUT_POINTS = QStringLiteral(
"OUTPUT_POINTS" );
34static const QString POINTS_MISSED = QStringLiteral(
"POINTS_MISSED" );
35static const QString POLYGONS_WITH_MISSED_POINTS = QStringLiteral(
"POLYGONS_WITH_MISSED_POINTS" );
36static const QString FEATURES_WITH_EMPTY_OR_NO_GEOMETRY = QStringLiteral(
"FEATURES_WITH_EMPTY_OR_NO_GEOMETRY" );
39QString QgsRandomPointsInPolygonsAlgorithm::name()
const
41 return QStringLiteral(
"randompointsinpolygons" );
44QString QgsRandomPointsInPolygonsAlgorithm::displayName()
const
46 return QObject::tr(
"Random points in polygons" );
49QStringList QgsRandomPointsInPolygonsAlgorithm::tags()
const
51 return QObject::tr(
"seed,attributes,create" ).split(
',' );
54QString QgsRandomPointsInPolygonsAlgorithm::group()
const
56 return QObject::tr(
"Vector creation" );
59QString QgsRandomPointsInPolygonsAlgorithm::groupId()
const
61 return QStringLiteral(
"vectorcreation" );
64void QgsRandomPointsInPolygonsAlgorithm::initAlgorithm(
const QVariantMap & )
67 std::unique_ptr< QgsProcessingParameterNumber > numberPointsParam = std::make_unique< QgsProcessingParameterNumber >( POINTS_NUMBER, QObject::tr(
"Number of points for each feature" ),
Qgis::ProcessingNumberParameterType::Integer, 1,
false, 1 );
68 numberPointsParam->setIsDynamic(
true );
70 numberPointsParam->setDynamicLayerParameterName( QStringLiteral(
"INPUT" ) );
71 addParameter( numberPointsParam.release() );
73 std::unique_ptr< QgsProcessingParameterDistance > minDistParam = std::make_unique< QgsProcessingParameterDistance >( MIN_DISTANCE, QObject::tr(
"Minimum distance between points" ), 0, INPUT,
true, 0 );
74 minDistParam->setIsDynamic(
true );
76 minDistParam->setDynamicLayerParameterName( QStringLiteral(
"INPUT" ) );
77 addParameter( minDistParam.release() );
79 std::unique_ptr< QgsProcessingParameterDistance > minDistGlobalParam = std::make_unique< QgsProcessingParameterDistance >( MIN_DISTANCE_GLOBAL, QObject::tr(
"Global minimum distance between points" ), 0, INPUT,
true, 0 );
81 addParameter( minDistGlobalParam.release() );
83 std::unique_ptr< QgsProcessingParameterNumber > maxAttemptsParam = std::make_unique< QgsProcessingParameterNumber >( MAX_TRIES_PER_POINT, QObject::tr(
"Maximum number of search attempts (for Min. dist. > 0)" ),
Qgis::ProcessingNumberParameterType::Integer, 10,
true, 1 );
85 maxAttemptsParam->setIsDynamic(
true );
87 maxAttemptsParam->setDynamicLayerParameterName( QStringLiteral(
"INPUT" ) );
88 addParameter( maxAttemptsParam.release() );
90 std::unique_ptr< QgsProcessingParameterNumber > randomSeedParam = std::make_unique< QgsProcessingParameterNumber >( SEED, QObject::tr(
"Random seed" ),
Qgis::ProcessingNumberParameterType::Integer, QVariant(),
true, 1 );
92 addParameter( randomSeedParam.release() );
94 std::unique_ptr< QgsProcessingParameterBoolean > includePolygonAttrParam = std::make_unique< QgsProcessingParameterBoolean >( INCLUDE_POLYGON_ATTRIBUTES, QObject::tr(
"Include polygon attributes" ),
true );
96 addParameter( includePolygonAttrParam.release() );
103 addOutput(
new QgsProcessingOutputNumber( POLYGONS_WITH_MISSED_POINTS, QObject::tr(
"Number of polygons with missed points" ) ) );
104 addOutput(
new QgsProcessingOutputNumber( FEATURES_WITH_EMPTY_OR_NO_GEOMETRY, QObject::tr(
"Number of features with empty or no geometry" ) ) );
107QString QgsRandomPointsInPolygonsAlgorithm::shortHelpString()
const
109 return QObject::tr(
"<p>This algorithm creates a point layer, with points placed randomly "
110 "in the polygons of the <i><b>Input polygon layer</b></i>.</p> "
111 "<ul><li>For each feature in the <i><b>Input polygon layer</b></i>, the algorithm attempts to add "
112 "the specified <i><b>Number of points for each feature</b></i> to the output layer.</li> "
113 "<li>A <i><b>Minimum distance between points</b></i> and a "
114 "<i><b>Global minimum distance between points</b></i> can be specified.<br> "
115 "A point will not be added if there is an already generated point within "
116 "this (Euclidean) distance from the generated location. "
117 "With <i>Minimum distance between points</i>, only points in the same "
118 "polygon feature are considered, while for <i>Global minimum distance "
119 "between points</i> all previously generated points are considered. "
120 "If the <i>Global minimum distance between points</i> is set equal to "
121 "or larger than the (local) <i>Minimum distance between points</i>, the "
122 "latter has no effect.<br> "
123 "If the <i>Minimum distance between points</i> is too large, "
124 "it may not be possible to generate the specified <i>Number of points "
125 "for each feature</i>, but all the generated points are returned.</li> "
126 "<li>The <i><b>Maximum number of attempts per point</b></i> can be specified.</li> "
127 "<li>The seed for the random generator can be provided (<b><i>Random seed</i></b> "
128 "- integer, greater than 0).</li> "
129 "<li>The user can choose not to <i><b>Include polygon feature attributes</b></i> in "
130 "the attributes of the generated point features.</li> "
132 "The total number of points will be<br> <b>'number of input features'</b> * "
133 "<i><b>Number of points for each feature</b></i><br> if there are no misses. "
134 "The <i>Number of points for each feature</i>, <i>Minimum distance between points</i> "
135 "and <i>Maximum number of attempts per point</i> can be data defined. "
136 "<p>Output from the algorithm:</p> "
138 "<li> The number of features with an empty or no geometry "
139 "(<code>FEATURES_WITH_EMPTY_OR_NO_GEOMETRY</code>).</li> "
140 "<li> A point layer containing the random points (<code>OUTPUT</code>).</li> "
141 "<li> The number of generated features (<code>OUTPUT_POINTS</code>).</li> "
142 "<li> The number of missed points (<code>POINTS_MISSED</code>).</li> "
143 "<li> The number of features with non-empty geometry and missing points "
144 "(<code>POLYGONS_WITH_MISSED_POINTS</code>).</li> "
150QgsRandomPointsInPolygonsAlgorithm *QgsRandomPointsInPolygonsAlgorithm::createInstance()
const
152 return new QgsRandomPointsInPolygonsAlgorithm();
157 mNumPoints = parameterAsInt( parameters, POINTS_NUMBER, context );
159 if ( mDynamicNumPoints )
160 mNumPointsProperty = parameters.value( POINTS_NUMBER ).value<
QgsProperty >();
162 mMinDistance = parameterAsDouble( parameters, MIN_DISTANCE, context );
164 if ( mDynamicMinDistance )
165 mMinDistanceProperty = parameters.value( MIN_DISTANCE ).value<
QgsProperty >();
167 mMaxAttempts = parameterAsInt( parameters, MAX_TRIES_PER_POINT, context );
169 if ( mDynamicMaxAttempts )
170 mMaxAttemptsProperty = parameters.value( MAX_TRIES_PER_POINT ).value<
QgsProperty >();
172 mMinDistanceGlobal = parameterAsDouble( parameters, MIN_DISTANCE_GLOBAL, context );
174 mUseRandomSeed = parameters.value( SEED ).isValid();
175 mRandSeed = parameterAsInt( parameters, SEED, context );
176 mIncludePolygonAttr = parameterAsBoolean( parameters, INCLUDE_POLYGON_ATTRIBUTES, context );
180QVariantMap QgsRandomPointsInPolygonsAlgorithm::processAlgorithm(
const QVariantMap ¶meters,
183 std::unique_ptr< QgsProcessingFeatureSource > polygonSource( parameterAsSource( parameters, INPUT, context ) );
184 if ( !polygonSource )
188 fields.
append(
QgsField( QStringLiteral(
"rand_point_id" ), QMetaType::Type::LongLong ) );
189 if ( mIncludePolygonAttr )
190 fields.
extend( polygonSource->fields() );
193 std::unique_ptr< QgsFeatureSink > sink( parameterAsSink( parameters, OUTPUT,
198 QgsExpressionContext expressionContext = createExpressionContext( parameters, context, polygonSource.get() );
201 std::random_device rd;
202 std::mt19937 mt( !mUseRandomSeed ? rd() : mRandSeed );
203 const std::uniform_real_distribution<> uniformDist( 0, 1 );
204 std::uniform_int_distribution<> uniformIntDist( 1, 999999999 );
211 int missedPoints = 0;
212 int missedPolygons = 0;
213 int emptyOrNullGeom = 0;
215 long long attempts = 0;
216 const long numberOfFeatures = polygonSource->featureCount();
217 long long desiredNumberOfPoints = 0;
218 const double featureProgressStep = 100.0 / ( numberOfFeatures > 0 ? numberOfFeatures : 1 );
219 double baseFeatureProgress = 0.0;
221 QgsFeatureIterator fitL = mIncludePolygonAttr || mDynamicNumPoints || mDynamicMinDistance || mDynamicMaxAttempts ? polygonSource->getFeatures()
234 baseFeatureProgress += featureProgressStep;
239 if ( polyGeom.isEmpty() )
243 baseFeatureProgress += featureProgressStep;
247 if ( mDynamicNumPoints || mDynamicMinDistance || mDynamicMaxAttempts )
253 int localIndexPoints = 0;
254 int pointsAddedForThisFeature = 0;
256 int numberPointsForThisFeature = mNumPoints;
257 if ( mDynamicNumPoints )
259 numberPointsForThisFeature = mNumPointsProperty.valueAsInt( expressionContext, 0 );
261 desiredNumberOfPoints += numberPointsForThisFeature;
262 int maxAttemptsForThisFeature = mMaxAttempts;
263 if ( mDynamicMaxAttempts )
264 maxAttemptsForThisFeature = mMaxAttemptsProperty.
valueAsInt( expressionContext, maxAttemptsForThisFeature );
265 double minDistanceForThisFeature = mMinDistance;
266 if ( mDynamicMinDistance )
267 minDistanceForThisFeature = mMinDistanceProperty.
valueAsDouble( expressionContext, minDistanceForThisFeature );
268 const double pointProgressIncrement = featureProgressStep / ( numberPointsForThisFeature * maxAttemptsForThisFeature );
269 double pointProgress = 0.0;
271 if ( ( minDistanceForThisFeature == 0 ) && ( mMinDistanceGlobal == 0 ) )
273 QVector< QgsPointXY > newPoints = polyGeom.randomPointsInPolygon( numberPointsForThisFeature, mUseRandomSeed ? uniformIntDist( mt ) : 0 );
274 for (
int i = 0; i < newPoints.length(); i++ )
280 pAttrs.append( totNPoints );
281 if ( mIncludePolygonAttr )
291 pointsAddedForThisFeature++;
292 pointProgress += pointProgressIncrement * ( maxAttemptsForThisFeature );
294 feedback->
setProgress( baseFeatureProgress + pointProgress );
300 QVector< QgsPointXY > newPoints = polyGeom.randomPointsInPolygon( numberPointsForThisFeature, [ & ](
const QgsPointXY & newPoint ) ->
bool
306 if ( minDistanceForThisFeature != 0 && mMinDistanceGlobal < minDistanceForThisFeature && localIndexPoints > 0 )
308 const QList<QgsFeatureId> neighbors = localIndex.
nearestNeighbor( newPoint, 1, minDistanceForThisFeature );
310 if ( !neighbors.empty() )
316 if ( mMinDistanceGlobal != 0.0 && indexPoints > 0 )
318 const QList<QgsFeatureId> neighbors = globalIndex.
nearestNeighbor( newPoint, 1, mMinDistanceGlobal );
320 if ( !neighbors.empty() )
328 pAttrs.append( attempts );
335 if ( minDistanceForThisFeature != 0 )
341 if ( mMinDistanceGlobal != 0.0 )
348 }, mUseRandomSeed ? uniformIntDist( mt ) : 0, feedback, maxAttemptsForThisFeature );
351 for (
int i = 0; i < newPoints.length(); i++ )
356 pAttrs.append( totNPoints );
357 if ( mIncludePolygonAttr )
367 pointsAddedForThisFeature++;
368 pointProgress += pointProgressIncrement * ( maxAttemptsForThisFeature );
370 feedback->
setProgress( baseFeatureProgress + pointProgress );
373 baseFeatureProgress += featureProgressStep;
374 if ( pointsAddedForThisFeature < numberPointsForThisFeature )
380 missedPoints = desiredNumberOfPoints - totNPoints;
381 feedback->
pushInfo( QObject::tr(
"Total number of points generated: "
382 "%1\nNumber of missed points: "
383 "%2\nPolygons with missing points: "
384 "%3\nFeatures with empty or missing "
386 ).arg( totNPoints ).arg( missedPoints ).arg( missedPolygons ).arg( emptyOrNullGeom ) );
388 outputs.insert( OUTPUT, ldest );
389 outputs.insert( OUTPUT_POINTS, totNPoints );
390 outputs.insert( POINTS_MISSED, missedPoints );
391 outputs.insert( POLYGONS_WITH_MISSED_POINTS, missedPolygons );
392 outputs.insert( FEATURES_WITH_EMPTY_OR_NO_GEOMETRY, emptyOrNullGeom );
@ VectorPoint
Vector point layers.
@ VectorPolygon
Vector polygon layers.
@ Advanced
Parameter is an advanced parameter which should be hidden from users by default.
Expression contexts are used to encapsulate the parameters around which a QgsExpression should be eva...
void setFeature(const QgsFeature &feature)
Convenience function for setting a feature for the context.
Wrapper for iterator of features from vector data provider or vector layer.
bool nextFeature(QgsFeature &f)
Fetch next feature and stores in f, returns true on success.
This class wraps a request for features to a vector layer (or directly its vector data provider).
QgsFeatureRequest & setNoAttributes()
Set that no attributes will be fetched.
@ FastInsert
Use faster inserts, at the cost of updating the passed features to reflect changes made at the provid...
The feature class encapsulates a single feature including its unique ID, geometry and a list of field...
void setAttributes(const QgsAttributes &attrs)
Sets the feature's attributes.
bool hasGeometry() const
Returns true if the feature has an associated geometry.
void setGeometry(const QgsGeometry &geometry)
Set the feature's geometry.
bool isCanceled() const
Tells whether the operation has been canceled already.
void setProgress(double progress)
Sets the current progress for the feedback object.
Encapsulate a field in an attribute table or data source.
Container of fields for a vector layer.
bool append(const QgsField &field, Qgis::FieldOrigin origin=Qgis::FieldOrigin::Provider, int originIndex=-1)
Appends a field.
void extend(const QgsFields &other)
Extends with fields from another QgsFields container.
A geometry is the spatial representation of a feature.
static QgsGeometry fromPointXY(const QgsPointXY &point)
Creates a new geometry from a QgsPointXY object.
A class to represent a 2D point.
Contains information about the context in which a processing algorithm is executed.
Custom exception class for processing related exceptions.
Base class for providing feedback from a processing algorithm.
virtual void pushInfo(const QString &info)
Pushes a general informational message from the algorithm.
A numeric output for processing algorithms.
A feature sink output for processing algorithms.
An input feature source (such as vector layers) parameter for processing algorithms.
static bool isDynamic(const QVariantMap ¶meters, const QString &name)
Returns true if the parameter with matching name is a dynamic parameter, and must be evaluated once f...
Definition for a property.
@ IntegerPositiveGreaterZero
Non-zero positive integer values.
@ IntegerPositive
Positive integer values (including 0)
@ DoublePositive
Positive double value (including 0)
A store for object properties.
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.
int valueAsInt(const QgsExpressionContext &context, int defaultValue=0, bool *ok=nullptr) const
Calculates the current value of the property and interprets it as an integer.
A spatial index for QgsFeature objects.
QList< QgsFeatureId > nearestNeighbor(const QgsPointXY &point, int neighbors=1, double maxDistance=0) const
Returns nearest neighbors to a point.
bool addFeature(QgsFeature &feature, QgsFeatureSink::Flags flags=QgsFeatureSink::Flags()) override
Adds a feature to the index.