QgsMeshContours Class Reference

Exporter of contours lines or polygons from a mesh layer. More...

#include <qgsmeshcontours.h>

Public Member Functions
	QgsMeshContours (const QgsTriangularMesh &triangularMesh, const QgsMesh &nativeMesh, const QVector< double > &datasetValues, const QgsMeshDataBlock scalarActiveFaceFlagValues)
	Constructs the mesh contours exporter directly with triangular mesh and dataset values to populate the cache with them.
	QgsMeshContours (QgsMeshLayer *layer)
	Constructs the mesh contours exporter.
	~QgsMeshContours ()
QgsGeometry	exportLines (const QgsMeshDatasetIndex &index, double value, QgsMeshRendererScalarSettings::DataResamplingMethod method, QgsFeedback *feedback=nullptr)
	Exports multi line string containing the contour line for particular dataset and value.
QgsGeometry	exportLines (double value, QgsFeedback *feedback=nullptr)
	Exports multi line string containing the contour line for particular value using the data stored in the cache.
QgsGeometry	exportPolygons (const QgsMeshDatasetIndex &index, double min_value, double max_value, QgsMeshRendererScalarSettings::DataResamplingMethod method, QgsFeedback *feedback=nullptr)
	Exports multi polygons representing the areas with values in range for particular dataset.
QgsGeometry	exportPolygons (double min_value, double max_value, QgsFeedback *feedback=nullptr)
	Exports multi polygons representing the areas with values in range using the data stored in the cache.

Detailed Description

Exporter of contours lines or polygons from a mesh layer.

Since

QGIS 3.12

Definition at line 51 of file qgsmeshcontours.h.

Constructor & Destructor Documentation

QgsMeshContours() [1/2]

QgsMeshContours::QgsMeshContours

(

QgsMeshLayer *

layer

)

Constructs the mesh contours exporter.

Caches the native and triangular mesh from data provider

Parameters

layer

mesh layer to be associated with this exporter

Definition at line 39 of file qgsmeshcontours.cpp.

QgsMeshContours() [2/2]

QgsMeshContours::QgsMeshContours	(	const QgsTriangularMesh &	triangularMesh,
		const QgsMesh &	nativeMesh,
		const QVector< double > &	datasetValues,
		const QgsMeshDataBlock	scalarActiveFaceFlagValues )

Constructs the mesh contours exporter directly with triangular mesh and dataset values to populate the cache with them.

The cache can't be changed. This instance can be used in a thread safe way.

Parameters

triangularMesh	triangular mesh of the meshlayer
nativeMesh	the native mesh of the mesh layer
datasetValues	the dataset values to used for creating contours defined on vertices
scalarActiveFaceFlagValues	active face flag values

Note

for data on faces, the values are averaged on vertices to define contours

Since

QGIS 3.18

Definition at line 53 of file qgsmeshcontours.cpp.

~QgsMeshContours()

QgsMeshContours::~QgsMeshContours ( )

default

Member Function Documentation

exportLines() [1/2]

QgsGeometry QgsMeshContours::exportLines	(	const QgsMeshDatasetIndex &	index,
		double	value,
		QgsMeshRendererScalarSettings::DataResamplingMethod	method,
		QgsFeedback *	feedback = nullptr )

Exports multi line string containing the contour line for particular dataset and value.

Parameters

index	dataset index that is used to update the cache
value	value of the contour line
method	for datasets defined on faces, the method will be used to convert data to vertices
feedback	optional feedback object for progress and cancellation support

Returns

MultiLineString geometry containing contour lines

Note

not thread safe

Definition at line 259 of file qgsmeshcontours.cpp.

exportLines() [2/2]

QgsGeometry QgsMeshContours::exportLines	(	double	value,
		QgsFeedback *	feedback = nullptr )

Exports multi line string containing the contour line for particular value using the data stored in the cache.

Parameters

value	value of the contour line
feedback	optional feedback object for progress and cancellation support

Returns

MultiLineString geometry containing contour lines

Note

thread safe

Since

QGIS 3.18

Definition at line 270 of file qgsmeshcontours.cpp.

exportPolygons() [1/2]

QgsGeometry QgsMeshContours::exportPolygons	(	const QgsMeshDatasetIndex &	index,
		double	min_value,
		double	max_value,
		QgsMeshRendererScalarSettings::DataResamplingMethod	method,
		QgsFeedback *	feedback = nullptr )

Exports multi polygons representing the areas with values in range for particular dataset.

Parameters

index	dataset index
min_value	minimum of the value interval for contour polygon
max_value	maximum of the value interval for contour polygon
method	for datasets defined on faces, the method will be used to convert data to vertices
feedback	optional feedback object for progress and cancellation support

Returns

MultiPolygon geometry containing contour polygons

Note

not thread safe

Definition at line 62 of file qgsmeshcontours.cpp.

exportPolygons() [2/2]

QgsGeometry QgsMeshContours::exportPolygons	(	double	min_value,
		double	max_value,
		QgsFeedback *	feedback = nullptr )

Exports multi polygons representing the areas with values in range using the data stored in the cache.

Parameters

min_value	minimum of the value interval for contour polygon
max_value	maximum of the value interval for contour polygon
feedback	optional feedback object for progress and cancellation support

Returns

MultiPolygon geometry containing contour polygons

Note

thread safe

Since

QGIS 3.18

Definition at line 78 of file qgsmeshcontours.cpp.

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The documentation for this class was generated from the following files:

• /build/qgis-3.99.0+git20251210+2fe06baccd8+99sid/src/analysis/mesh/qgsmeshcontours.h
• /build/qgis-3.99.0+git20251210+2fe06baccd8+99sid/src/analysis/mesh/qgsmeshcontours.cpp