Abstract base class for all geometries. More...

#include <qgsabstractgeometry.h>

Inheritance diagram for QgsAbstractGeometry:

[legend]

Classes
class	const_part_iterator
	The part_iterator class provides STL-style iterator for const references to geometry parts. More...

class	part_iterator
	The part_iterator class provides STL-style iterator for geometry parts. More...

class	vertex_iterator
	The vertex_iterator class provides STL-style iterator for vertices. More...

Public Types
enum	AxisOrder { XY = 0 , YX }
	Axis order for GML generation. More...

enum	SegmentationToleranceType { MaximumAngle = 0 , MaximumDifference }
	Segmentation tolerance as maximum angle or maximum difference between approximation and circle. More...

enum	WkbFlag { FlagExportTrianglesAsPolygons = 1 << 0 , FlagExportNanAsDoubleMin = 1 << 1 }
	WKB export flags. More...

typedef QFlags< WkbFlag >	WkbFlags

Public Member Functions
	QgsAbstractGeometry ()=default

	QgsAbstractGeometry (const QgsAbstractGeometry &geom)

virtual	~QgsAbstractGeometry ()=default

virtual bool	addMValue (double mValue=0)=0
	Adds a measure to the geometry, initialized to a preset value.

virtual bool	addZValue (double zValue=0)=0
	Adds a z-dimension to the geometry, initialized to a preset value.

virtual void	adjacentVertices (QgsVertexId vertex, QgsVertexId &previousVertex, QgsVertexId &nextVertex) const =0
	Returns the vertices adjacent to a specified vertex within a geometry.

virtual double	area () const
	Returns the planar, 2-dimensional area of the geometry.

virtual QDomElement	asGml2 (QDomDocument &doc, int precision=17, const QString &ns="gml", AxisOrder axisOrder=QgsAbstractGeometry::AxisOrder::XY) const =0
	Returns a GML2 representation of the geometry.

virtual QDomElement	asGml3 (QDomDocument &doc, int precision=17, const QString &ns="gml", AxisOrder axisOrder=QgsAbstractGeometry::AxisOrder::XY) const =0
	Returns a GML3 representation of the geometry.

QString	asJson (int precision=17)
	Returns a GeoJSON representation of the geometry as a QString.

virtual json	asJsonObject (int precision=17) const
	Returns a json object representation of the geometry.

virtual QString	asKml (int precision=17) const =0
	Returns a KML representation of the geometry.

virtual QPainterPath	asQPainterPath () const =0
	Returns the geometry represented as a QPainterPath.

virtual QByteArray	asWkb (WkbFlags flags=QgsAbstractGeometry::WkbFlags()) const =0
	Returns a WKB representation of the geometry.

virtual QString	asWkt (int precision=17) const =0
	Returns a WKT representation of the geometry.

virtual QgsAbstractGeometry *	boundary () const =0
	Returns the closure of the combinatorial boundary of the geometry (ie the topological boundary of the geometry).

virtual QgsRectangle	boundingBox () const
	Returns the minimal bounding box for the geometry.

virtual QgsBox3D	boundingBox3D () const =0
	Returns the 3D bounding box for the geometry.

virtual bool	boundingBoxIntersects (const QgsBox3D &box3d) const
	Returns `true` if the bounding box of this geometry intersects with a box3d.

virtual bool	boundingBoxIntersects (const QgsRectangle &rectangle) const
	Returns `true` if the bounding box of this geometry intersects with a rectangle.

virtual QgsPoint	centroid () const
	Returns the centroid of the geometry.

virtual void	clear ()=0
	Clears the geometry, ie reset it to a null geometry.

virtual QgsAbstractGeometry *	clone () const =0
	Clones the geometry by performing a deep copy.

virtual double	closestSegment (const QgsPoint &pt, QgsPoint &segmentPt, QgsVertexId &vertexAfter, int leftOf=nullptr, double epsilon=4 std::numeric_limits< double >::epsilon()) const =0
	Searches for the closest segment of the geometry to a given point.

virtual int	compareTo (const QgsAbstractGeometry *other) const
	Comparator for sorting of geometry.

const_part_iterator	const_parts_begin () const
	Returns STL-style iterator pointing to the const first part of the geometry.

const_part_iterator	const_parts_end () const
	Returns STL-style iterator pointing to the imaginary const part after the last part of the geometry.

virtual bool	convertTo (Qgis::WkbType type)
	Converts the geometry to a specified type.

virtual QgsCoordinateSequence	coordinateSequence () const =0
	Retrieves the sequence of geometries, rings and nodes.

virtual QgsAbstractGeometry *	createEmptyWithSameType () const =0
	Creates a new geometry with the same class and same WKB type as the original and transfers ownership.

virtual bool	deleteVertex (QgsVertexId position)=0
	Deletes a vertex within the geometry.

virtual int	dimension () const =0
	Returns the inherent dimension of the geometry.

virtual void	draw (QPainter &p) const =0
	Draws the geometry using the specified QPainter.

virtual bool	dropMValue ()=0
	Drops any measure values which exist in the geometry.

virtual bool	dropZValue ()=0
	Drops any z-dimensions which exist in the geometry.

virtual void	filterVertices (const std::function< bool(const QgsPoint &) > &filter)
	Filters the vertices from the geometry in place, removing any which do not return `true` for the filter function check.

virtual bool	fromWkb (QgsConstWkbPtr &wkb)=0
	Sets the geometry from a WKB string.

virtual bool	fromWkt (const QString &wkt)=0
	Sets the geometry from a WKT string.

virtual bool	fuzzyDistanceEqual (const QgsAbstractGeometry &other, double epsilon=1e-8) const =0
	Performs fuzzy distance comparison between this geometry and other using an epsilon.

virtual bool	fuzzyEqual (const QgsAbstractGeometry &other, double epsilon=1e-8) const =0
	Performs fuzzy comparison between this geometry and other using an epsilon.

virtual QString	geometryType () const =0
	Returns a unique string representing the geometry type.

virtual bool	hasCurvedSegments () const
	Returns `true` if the geometry contains curved segments.

virtual bool	insertVertex (QgsVertexId position, const QgsPoint &vertex)=0
	Inserts a vertex into the geometry.

bool	is3D () const
	Returns `true` if the geometry is 3D and contains a z-value.

virtual bool	isEmpty () const
	Returns `true` if the geometry is empty.

bool	isMeasure () const
	Returns `true` if the geometry contains m values.

virtual bool	isValid (QString &error, Qgis::GeometryValidityFlags flags=Qgis::GeometryValidityFlags()) const =0
	Checks validity of the geometry, and returns `true` if the geometry is valid.

virtual double	length () const
	Returns the planar, 2-dimensional length of the geometry.

virtual bool	moveVertex (QgsVertexId position, const QgsPoint &newPos)=0
	Moves a vertex within the geometry.

virtual int	nCoordinates () const
	Returns the number of nodes contained in the geometry.

virtual bool	nextVertex (QgsVertexId &id, QgsPoint &vertex) const =0
	Returns next vertex id and coordinates.

virtual void	normalize ()=0
	Reorganizes the geometry into a normalized form (or "canonical" form).

virtual bool	operator!= (const QgsAbstractGeometry &other) const =0

QgsAbstractGeometry &	operator= (const QgsAbstractGeometry &geom)

virtual bool	operator== (const QgsAbstractGeometry &other) const =0

virtual int	partCount () const =0
	Returns count of parts contained in the geometry.

QgsGeometryPartIterator	parts ()
	Returns Java-style iterator for traversal of parts of the geometry.

QgsGeometryConstPartIterator	parts () const
	Returns Java-style iterator for traversal of parts of the geometry.

part_iterator	parts_begin ()
	Returns STL-style iterator pointing to the first part of the geometry.

part_iterator	parts_end ()
	Returns STL-style iterator pointing to the imaginary part after the last part of the geometry.

virtual double	perimeter () const
	Returns the planar, 2-dimensional perimeter of the geometry.

virtual bool	removeDuplicateNodes (double epsilon=4 *std::numeric_limits< double >::epsilon(), bool useZValues=false)=0
	Removes duplicate nodes from the geometry, wherever removing the nodes does not result in a degenerate geometry.

virtual int	ringCount (int part=0) const =0
	Returns the number of rings of which this geometry is built.

virtual QgsAbstractGeometry *	segmentize (double tolerance=M_PI/180., SegmentationToleranceType toleranceType=MaximumAngle) const
	Returns a version of the geometry without curves.

virtual double	segmentLength (QgsVertexId startVertex) const =0
	Returns the length of the segment of the geometry which begins at startVertex.

virtual const QgsAbstractGeometry *	simplifiedTypeRef () const
	Returns a reference to the simplest lossless representation of this geometry, e.g.

virtual QgsAbstractGeometry *	simplifyByDistance (double tolerance) const =0
	Simplifies the geometry by applying the Douglas Peucker simplification by distance algorithm.

virtual QgsAbstractGeometry *	snappedToGrid (double hSpacing, double vSpacing, double dSpacing=0, double mSpacing=0, bool removeRedundantPoints=false) const =0
	Makes a new geometry with all the points or vertices snapped to the closest point of the grid.

virtual void	swapXy ()=0
	Swaps the x and y coordinates from the geometry.

virtual QgsAbstractGeometry *	toCurveType () const =0
	Returns the geometry converted to the more generic curve type.

virtual void	transform (const QgsCoordinateTransform &ct, Qgis::TransformDirection d=Qgis::TransformDirection::Forward, bool transformZ=false)=0
	Transforms the geometry using a coordinate transform.

virtual void	transform (const QTransform &t, double zTranslate=0.0, double zScale=1.0, double mTranslate=0.0, double mScale=1.0)=0
	Transforms the x and y components of the geometry using a QTransform object t.

virtual bool	transform (QgsAbstractGeometryTransformer transformer, QgsFeedback feedback=nullptr)=0
	Transforms the vertices from the geometry in place, using the specified geometry transformer object.

virtual void	transformVertices (const std::function< QgsPoint(const QgsPoint &) > &transform)
	Transforms the vertices from the geometry in place, applying the transform function to every vertex.

virtual double	vertexAngle (QgsVertexId vertex) const =0
	Returns approximate angle at a vertex.

virtual QgsPoint	vertexAt (QgsVertexId id) const =0
	Returns the point corresponding to a specified vertex id.

virtual int	vertexCount (int part=0, int ring=0) const =0
	Returns the number of vertices of which this geometry is built.

virtual int	vertexNumberFromVertexId (QgsVertexId id) const =0
	Returns the vertex number corresponding to a vertex id.

QgsVertexIterator	vertices () const
	Returns a read-only, Java-style iterator for traversal of vertices of all the geometry, including all geometry parts and rings.

vertex_iterator	vertices_begin () const
	Returns STL-style iterator pointing to the first vertex of the geometry.

vertex_iterator	vertices_end () const
	Returns STL-style iterator pointing to the imaginary vertex after the last vertex of the geometry.

virtual int	wkbSize (QgsAbstractGeometry::WkbFlags flags=QgsAbstractGeometry::WkbFlags()) const =0
	Returns the length of the QByteArray returned by asWkb()

Qgis::WkbType	wkbType () const
	Returns the WKB type of the geometry.

QString	wktTypeStr () const
	Returns the WKT type string of the geometry.

Protected Member Functions
virtual QgsRectangle	calculateBoundingBox () const
	Default calculator for the minimal bounding box for the geometry.

virtual QgsBox3D	calculateBoundingBox3D () const
	Calculates the minimal 3D bounding box for the geometry.

virtual int	childCount () const
	Returns number of child geometries (for geometries with child geometries) or child points (for geometries without child geometries - i.e.

virtual QgsAbstractGeometry *	childGeometry (int index) const
	Returns pointer to child geometry (for geometries with child geometries - i.e.

virtual QgsPoint	childPoint (int index) const
	Returns point at index (for geometries without child geometries - i.e.

virtual void	clearCache () const
	Clears any cached parameters associated with the geometry, e.g., bounding boxes.

virtual int	compareToSameClass (const QgsAbstractGeometry *other) const =0
	Compares to an other geometry of the same class, and returns a integer for sorting of the two geometries.

virtual bool	hasChildGeometries () const
	Returns whether the geometry has any child geometries (`false` for point / curve, `true` otherwise)

void	setZMTypeFromSubGeometry (const QgsAbstractGeometry *subggeom, Qgis::WkbType baseGeomType)
	Updates the geometry type based on whether sub geometries contain z or m values.

int	sortIndex () const
	Returns the sort index for the geometry, used in the compareTo() method to compare geometries of different types.

Protected Attributes
Qgis::WkbType	mWkbType = Qgis::WkbType::Unknown

Friends
class	TestQgsGeometry

Detailed Description

Abstract base class for all geometries.

Note: QgsAbstractGeometry objects are inherently Cartesian/planar geometries. They have no concept of geodesy, and none of the methods or properties exposed from the QgsAbstractGeometry API (or QgsGeometry API) utilize geodesic calculations. Accordingly, properties like length() and area() and spatial operations like centroid() are always calculated using strictly Cartesian mathematics. In contrast, the QgsDistanceArea class exposes methods for working with geodesic calculations and spatial operations on geometries, and should be used whenever calculations which account for the curvature of the Earth (or any other celestial body) are required.

Definition at line 79 of file qgsabstractgeometry.h.

Member Typedef Documentation

◆ WkbFlags

typedef QFlags< WkbFlag > QgsAbstractGeometry::WkbFlags

Definition at line 308 of file qgsabstractgeometry.h.

Member Enumeration Documentation

◆ AxisOrder

enum QgsAbstractGeometry::AxisOrder

Axis order for GML generation.

Enumerator
XY	X comes before Y (or lon before lat)
YX	Y comes before X (or lat before lon)

Definition at line 138 of file qgsabstractgeometry.h.

◆ SegmentationToleranceType

enum QgsAbstractGeometry::SegmentationToleranceType

Segmentation tolerance as maximum angle or maximum difference between approximation and circle.

Enumerator
MaximumAngle	Maximum angle between generating radii (lines from arc center to output vertices)
MaximumDifference	Maximum distance between an arbitrary point on the original curve and closest point on its approximation.

Definition at line 120 of file qgsabstractgeometry.h.

◆ WkbFlag

enum QgsAbstractGeometry::WkbFlag

WKB export flags.

Since: QGIS 3.14

Enumerator

FlagExportTrianglesAsPolygons

Triangles should be exported as polygon geometries.

FlagExportNanAsDoubleMin

Use -DOUBLE_MAX to represent NaN.

Since: QGIS 3.30

Definition at line 303 of file qgsabstractgeometry.h.

Constructor & Destructor Documentation

◆ QgsAbstractGeometry() [1/2]

QgsAbstractGeometry::QgsAbstractGeometry ( )

default

◆ ~QgsAbstractGeometry()

virtual QgsAbstractGeometry::~QgsAbstractGeometry ( )

virtualdefault

◆ QgsAbstractGeometry() [2/2]

QgsAbstractGeometry::QgsAbstractGeometry ( const QgsAbstractGeometry & geom )

Definition at line 28 of file qgsabstractgeometry.cpp.

Member Function Documentation

◆ addMValue()

virtual bool QgsAbstractGeometry::addMValue ( double mValue = 0 )

pure virtual

Adds a measure to the geometry, initialized to a preset value.

Parameters

mValue initial m-value for all nodes

Returns: true on success

See also: dropMValue(); addZValue()

Implemented in QgsCircularString, QgsCompoundCurve, QgsCurvePolygon, QgsGeometryCollection, QgsLineString, QgsPoint, and QgsPolyhedralSurface.

◆ addZValue()

virtual bool QgsAbstractGeometry::addZValue ( double zValue = 0 )

pure virtual

Adds a z-dimension to the geometry, initialized to a preset value.

Parameters

zValue initial z-value for all nodes

Returns: true on success

See also: dropZValue(); addMValue()

Implemented in QgsCircularString, QgsCompoundCurve, QgsCurvePolygon, QgsGeometryCollection, QgsLineString, QgsPoint, and QgsPolyhedralSurface.

◆ adjacentVertices()

virtual void QgsAbstractGeometry::adjacentVertices	(	QgsVertexId	vertex,
		QgsVertexId &	previousVertex,
		QgsVertexId &	nextVertex
	)		const

pure virtual

Returns the vertices adjacent to a specified vertex within a geometry.

Implemented in QgsCurve, QgsCurvePolygon, QgsGeometryCollection, QgsPoint, and QgsPolyhedralSurface.

◆ area()

double QgsAbstractGeometry::area ( ) const

virtual

Returns the planar, 2-dimensional area of the geometry.

Warning: QgsAbstractGeometry objects are inherently Cartesian/planar geometries, and the area returned by this method is calculated using strictly Cartesian mathematics. In contrast, the QgsDistanceArea class exposes methods for calculating the areas of geometries using geodesic calculations which account for the curvature of the Earth (or any other celestial body).

See also: length(); perimeter()

Reimplemented in QgsCurvePolygon, QgsGeometryCollection, and QgsPolyhedralSurface.

Definition at line 207 of file qgsabstractgeometry.cpp.

◆ asGml2()

virtual QDomElement QgsAbstractGeometry::asGml2	(	QDomDocument &	doc,
		int	precision = `17`,
		const QString &	ns = `"gml"`,
		AxisOrder	axisOrder = `QgsAbstractGeometry::AxisOrder::XY`
	)		const

pure virtual

Returns a GML2 representation of the geometry.

Parameters

doc	DOM document
precision	number of decimal places for coordinates
ns	XML namespace
axisOrder	Axis order for generated GML

See also: asWkb(); asWkt(); asGml3(); asJson()

Implemented in QgsCircularString, QgsCompoundCurve, QgsCurvePolygon, QgsGeometryCollection, QgsLineString, QgsMultiCurve, QgsMultiLineString, QgsMultiPoint, QgsMultiPolygon, QgsMultiSurface, QgsPoint, QgsPolyhedralSurface, and QgsTriangulatedSurface.

◆ asGml3()

virtual QDomElement QgsAbstractGeometry::asGml3	(	QDomDocument &	doc,
		int	precision = `17`,
		const QString &	ns = `"gml"`,
		AxisOrder	axisOrder = `QgsAbstractGeometry::AxisOrder::XY`
	)		const

pure virtual

Returns a GML3 representation of the geometry.

Parameters

doc	DOM document
precision	number of decimal places for coordinates
ns	XML namespace
axisOrder	Axis order for generated GML

See also: asWkb(); asWkt(); asGml2(); asJson()

Implemented in QgsCircularString, QgsCompoundCurve, QgsCurvePolygon, QgsGeometryCollection, QgsLineString, QgsMultiCurve, QgsMultiLineString, QgsMultiPoint, QgsMultiPolygon, QgsMultiSurface, QgsPoint, QgsPolyhedralSurface, QgsTriangle, and QgsTriangulatedSurface.

◆ asJson()

QString QgsAbstractGeometry::asJson ( int precision = 17 )

Returns a GeoJSON representation of the geometry as a QString.

Parameters

precision number of decimal places for coordinates

See also: asWkb(); asWkt(); asGml2(); asGml3(); asJsonObject()

Definition at line 227 of file qgsabstractgeometry.cpp.

◆ asJsonObject()

json QgsAbstractGeometry::asJsonObject ( int precision = 17 ) const

virtual

Returns a json object representation of the geometry.

See also: asWkb(); asWkt(); asGml2(); asGml3(); asJson()

Note: not available in Python bindings

Since: QGIS 3.10

Reimplemented in QgsCircularString, QgsCompoundCurve, QgsCurvePolygon, QgsGeometryCollection, QgsLineString, QgsMultiCurve, QgsMultiLineString, QgsMultiPoint, QgsMultiPolygon, QgsMultiSurface, QgsPoint, and QgsPolyhedralSurface.

Definition at line 232 of file qgsabstractgeometry.cpp.

◆ asKml()

virtual QString QgsAbstractGeometry::asKml ( int precision = 17 ) const

pure virtual

Returns a KML representation of the geometry.

Since: QGIS 3.12

Implemented in QgsCurve, QgsCurvePolygon, QgsGeometryCollection, QgsLineString, QgsPoint, QgsPolyhedralSurface, and QgsTriangulatedSurface.

◆ asQPainterPath()

virtual QPainterPath QgsAbstractGeometry::asQPainterPath ( ) const

pure virtual

Returns the geometry represented as a QPainterPath.

Warning: not all geometry subclasses can be represented by a QPainterPath, e.g. points and multipoint geometries will return an empty path.

Since: QGIS 3.16

Implemented in QgsCurve, QgsCurvePolygon, QgsGeometryCollection, QgsPoint, and QgsPolyhedralSurface.

◆ asWkb()

virtual QByteArray QgsAbstractGeometry::asWkb ( WkbFlags flags = QgsAbstractGeometry::WkbFlags() ) const

pure virtual

Returns a WKB representation of the geometry.

The optional flags argument specifies flags controlling WKB export behavior (since QGIS 3.14).

See also: asWkt; asGml2; asGml3; asJson()

Implemented in QgsCircularString, QgsCompoundCurve, QgsCurvePolygon, QgsGeometryCollection, QgsLineString, QgsPolygon, QgsPolyhedralSurface, and QgsPoint.

◆ asWkt()

virtual QString QgsAbstractGeometry::asWkt ( int precision = 17 ) const

pure virtual

Returns a WKT representation of the geometry.

Parameters

precision number of decimal places for coordinates

See also: asWkb(); asGml2(); asGml3(); asJson()

Implemented in QgsCircularString, QgsCompoundCurve, QgsCurvePolygon, QgsGeometryCollection, QgsLineString, QgsPoint, QgsPolygon, and QgsPolyhedralSurface.

◆ boundary()

virtual QgsAbstractGeometry * QgsAbstractGeometry::boundary ( ) const

pure virtual

Returns the closure of the combinatorial boundary of the geometry (ie the topological boundary of the geometry).

For instance, a polygon geometry will have a boundary consisting of the linestrings for each ring in the polygon.

Returns: boundary for geometry. May be nullptr for some geometry types.

Implemented in QgsCurve, QgsCurvePolygon, QgsGeometryCollection, QgsMultiCurve, QgsMultiPoint, QgsMultiPolygon, QgsMultiSurface, QgsPoint, QgsPolygon, QgsPolyhedralSurface, and QgsTriangle.

◆ boundingBox()

QgsRectangle QgsAbstractGeometry::boundingBox ( ) const

virtual

Returns the minimal bounding box for the geometry.

Definition at line 118 of file qgsabstractgeometry.cpp.

◆ boundingBox3D()

virtual QgsBox3D QgsAbstractGeometry::boundingBox3D ( ) const

pure virtual

Returns the 3D bounding box for the geometry.

Since: QGIS 3.34

Implemented in QgsCurve, QgsGeometryCollection, QgsPoint, and QgsSurface.

◆ boundingBoxIntersects() [1/2]

bool QgsAbstractGeometry::boundingBoxIntersects ( const QgsBox3D & box3d ) const

virtual

Returns true if the bounding box of this geometry intersects with a box3d.

Since this test only considers the bounding box of the geometry, is is very fast to calculate and handles invalid geometries.

Since: QGIS 3.34

Reimplemented in QgsCompoundCurve, QgsCurvePolygon, QgsGeometryCollection, QgsLineString, QgsPoint, and QgsPolyhedralSurface.

Definition at line 431 of file qgsabstractgeometry.cpp.

◆ boundingBoxIntersects() [2/2]

bool QgsAbstractGeometry::boundingBoxIntersects ( const QgsRectangle & rectangle ) const

virtual

Returns true if the bounding box of this geometry intersects with a rectangle.

Since this test only considers the bounding box of the geometry, is is very fast to calculate and handles invalid geometries.

Since: QGIS 3.20

Reimplemented in QgsLineString, and QgsPoint.

Definition at line 426 of file qgsabstractgeometry.cpp.

◆ calculateBoundingBox()

QgsRectangle QgsAbstractGeometry::calculateBoundingBox ( ) const

protectedvirtual

Default calculator for the minimal bounding box for the geometry.

Derived classes should override this method if a more efficient bounding box calculation is available.

Definition at line 123 of file qgsabstractgeometry.cpp.

◆ calculateBoundingBox3D()

QgsBox3D QgsAbstractGeometry::calculateBoundingBox3D ( ) const

protectedvirtual

Calculates the minimal 3D bounding box for the geometry.

See also: calculateBoundingBox()

Since: QGIS 3.34

Reimplemented in QgsCircularString, QgsCompoundCurve, QgsCurvePolygon, QgsGeometryCollection, QgsLineString, and QgsPolyhedralSurface.

Definition at line 128 of file qgsabstractgeometry.cpp.

◆ centroid()

QgsPoint QgsAbstractGeometry::centroid ( ) const

virtual

Returns the centroid of the geometry.

Reimplemented in QgsLineString.

Definition at line 237 of file qgsabstractgeometry.cpp.

◆ childCount()

virtual int QgsAbstractGeometry::childCount ( ) const

inlineprotectedvirtual

Returns number of child geometries (for geometries with child geometries) or child points (for geometries without child geometries - i.e.

curve / point)

Note: used for vertex_iterator implementation

Reimplemented in QgsCurve, QgsCurvePolygon, QgsGeometryCollection, QgsPoint, and QgsPolyhedralSurface.

Definition at line 1140 of file qgsabstractgeometry.h.

◆ childGeometry()

virtual QgsAbstractGeometry * QgsAbstractGeometry::childGeometry ( int index ) const

inlineprotectedvirtual

Returns pointer to child geometry (for geometries with child geometries - i.e.

geom. collection / polygon)

Note: used for vertex_iterator implementation

Reimplemented in QgsCurvePolygon, QgsGeometryCollection, and QgsPolyhedralSurface.

Definition at line 1146 of file qgsabstractgeometry.h.

◆ childPoint()

QgsPoint QgsAbstractGeometry::childPoint ( int index ) const

protectedvirtual

Returns point at index (for geometries without child geometries - i.e.

curve / point)

Note: used for vertex_iterator implementation

Reimplemented in QgsCurve, and QgsPoint.

Definition at line 408 of file qgsabstractgeometry.cpp.

◆ clear()

virtual void QgsAbstractGeometry::clear ( )

pure virtual

Clears the geometry, ie reset it to a null geometry.

Implemented in QgsCircularString, QgsCompoundCurve, QgsCurvePolygon, QgsGeometryCollection, QgsLineString, QgsMultiCurve, QgsMultiLineString, QgsMultiPoint, QgsMultiPolygon, QgsMultiSurface, QgsPoint, QgsPolygon, QgsPolyhedralSurface, QgsTriangle, and QgsTriangulatedSurface.

◆ clearCache()

void QgsAbstractGeometry::clearCache ( ) const

protectedvirtual

Clears any cached parameters associated with the geometry, e.g., bounding boxes.

Reimplemented in QgsCurve, QgsGeometryCollection, and QgsSurface.

Definition at line 177 of file qgsabstractgeometry.cpp.

◆ clone()

virtual QgsAbstractGeometry * QgsAbstractGeometry::clone ( ) const

pure virtual

Clones the geometry by performing a deep copy.

Implemented in QgsCircularString, QgsCompoundCurve, QgsCurvePolygon, QgsGeometryCollection, QgsLineString, QgsMultiCurve, QgsMultiLineString, QgsMultiPoint, QgsMultiPolygon, QgsMultiSurface, QgsPoint, QgsPolygon, QgsPolyhedralSurface, QgsTriangle, QgsTriangulatedSurface, and QgsCurve.

◆ closestSegment()

virtual double QgsAbstractGeometry::closestSegment	(	const QgsPoint &	pt,
		QgsPoint &	segmentPt,
		QgsVertexId &	vertexAfter,
		int *	leftOf = `nullptr`,
		double	epsilon = `4 *std::numeric_limits< double >::epsilon()`
	)		const

pure virtual

Searches for the closest segment of the geometry to a given point.

Parameters

pt	specifies the point to find closest segment to
segmentPt	storage for the closest point within the geometry
vertexAfter	storage for the ID of the vertex at the end of the closest segment
leftOf	indicates whether the point lies on the left side of the geometry (-1 if point is to the left of the geometry, +1 if the point is to the right of the geometry, or 0 for cases where left/right could not be determined, e.g. point exactly on a line) `false` if point is to right of segment)
epsilon	epsilon for segment snapping

Returns: squared distance to closest segment or negative value on error

Implemented in QgsCircularString, QgsCompoundCurve, QgsCurvePolygon, QgsGeometryCollection, QgsLineString, QgsPoint, and QgsPolyhedralSurface.

◆ compareTo()

int QgsAbstractGeometry::compareTo ( const QgsAbstractGeometry * other ) const

virtual

Comparator for sorting of geometry.

Since: QGIS 3.20

Definition at line 43 of file qgsabstractgeometry.cpp.

◆ compareToSameClass()

virtual int QgsAbstractGeometry::compareToSameClass ( const QgsAbstractGeometry * other ) const

protectedpure virtual

Compares to an other geometry of the same class, and returns a integer for sorting of the two geometries.

Note: The actual logic for the sorting is an internal detail only and is subject to change between QGIS versions. The result should only be used for direct comparison of geometries and not stored for later use.

Since: QGIS 3.20

Implemented in QgsCircularString, QgsCompoundCurve, QgsCurvePolygon, QgsGeometryCollection, QgsLineString, QgsPoint, QgsTriangulatedSurface, and QgsPolyhedralSurface.

◆ const_parts_begin()

const_part_iterator QgsAbstractGeometry::const_parts_begin ( ) const

inline

Returns STL-style iterator pointing to the const first part of the geometry.

See also: const_parts_end()

Since: QGIS 3.6

Definition at line 949 of file qgsabstractgeometry.h.

◆ const_parts_end()

QgsAbstractGeometry::const_part_iterator QgsAbstractGeometry::const_parts_end ( ) const

Returns STL-style iterator pointing to the imaginary const part after the last part of the geometry.

See also: const_parts_begin()

Since: QGIS 3.6

Definition at line 354 of file qgsabstractgeometry.cpp.

◆ convertTo()

bool QgsAbstractGeometry::convertTo ( Qgis::WkbType type )

virtual

Converts the geometry to a specified type.

Returns: true if conversion was successful

Reimplemented in QgsLineString, and QgsPoint.

Definition at line 292 of file qgsabstractgeometry.cpp.

◆ coordinateSequence()

virtual QgsCoordinateSequence QgsAbstractGeometry::coordinateSequence ( ) const

pure virtual

Retrieves the sequence of geometries, rings and nodes.

Returns: coordinate sequence

Implemented in QgsCurve, QgsCurvePolygon, QgsGeometryCollection, QgsPoint, and QgsPolyhedralSurface.

◆ createEmptyWithSameType()

virtual QgsAbstractGeometry * QgsAbstractGeometry::createEmptyWithSameType ( ) const

pure virtual

Creates a new geometry with the same class and same WKB type as the original and transfers ownership.

To create it, the geometry is default constructed and then the WKB is changed.

See also: clone()

Implemented in QgsCircularString, QgsCompoundCurve, QgsCurvePolygon, QgsGeometryCollection, QgsLineString, QgsMultiCurve, QgsMultiLineString, QgsMultiPoint, QgsMultiPolygon, QgsMultiSurface, QgsPoint, QgsPolygon, QgsPolyhedralSurface, QgsTriangle, and QgsTriangulatedSurface.

◆ deleteVertex()

virtual bool QgsAbstractGeometry::deleteVertex ( QgsVertexId position )

pure virtual

Deletes a vertex within the geometry.

Parameters

position vertex id for vertex to delete

Returns: true if delete was successful

See also: insertVertex; moveVertex

Implemented in QgsCircularString, QgsCompoundCurve, QgsCurvePolygon, QgsGeometryCollection, QgsLineString, QgsPoint, QgsPolyhedralSurface, QgsTriangle, and QgsTriangulatedSurface.

◆ dimension()

virtual int QgsAbstractGeometry::dimension ( ) const

pure virtual

Returns the inherent dimension of the geometry.

For example, this is 0 for a point geometry, 1 for a linestring and 2 for a polygon.

Implemented in QgsPolyhedralSurface, QgsCircularString, QgsCompoundCurve, QgsCurvePolygon, QgsGeometryCollection, QgsLineString, and QgsPoint.

◆ draw()

virtual void QgsAbstractGeometry::draw ( QPainter & p ) const

pure virtual

Draws the geometry using the specified QPainter.

Parameters

p	destination QPainter

Implemented in QgsCircularString, QgsCompoundCurve, QgsCurvePolygon, QgsGeometryCollection, QgsLineString, QgsPoint, and QgsPolyhedralSurface.

◆ dropMValue()

virtual bool QgsAbstractGeometry::dropMValue ( )

pure virtual

Drops any measure values which exist in the geometry.

Returns: true if m-values were present and have been removed

See also: addMValue(); dropZValue()

Implemented in QgsCircularString, QgsCompoundCurve, QgsCurvePolygon, QgsGeometryCollection, QgsLineString, QgsPoint, and QgsPolyhedralSurface.

◆ dropZValue()

virtual bool QgsAbstractGeometry::dropZValue ( )

pure virtual

Drops any z-dimensions which exist in the geometry.

Returns: true if Z values were present and have been removed

See also: addZValue(); dropMValue()

Implemented in QgsCircularString, QgsCompoundCurve, QgsCurvePolygon, QgsGeometryCollection, QgsLineString, QgsPoint, and QgsPolyhedralSurface.

◆ filterVertices()

void QgsAbstractGeometry::filterVertices ( const std::function< bool(const QgsPoint &) > & filter )

virtual

Filters the vertices from the geometry in place, removing any which do not return true for the filter function check.

Has no meaning when called on a single point geometry.

Depending on the filter used, this may result in an invalid geometry.

Note: Not available in Python bindings

Since: QGIS 3.2

Reimplemented in QgsCircularString, QgsCompoundCurve, QgsCurvePolygon, QgsGeometryCollection, QgsLineString, QgsMultiPoint, QgsPoint, and QgsPolyhedralSurface.

Definition at line 328 of file qgsabstractgeometry.cpp.

◆ fromWkb()

virtual bool QgsAbstractGeometry::fromWkb ( QgsConstWkbPtr & wkb )

pure virtual

Sets the geometry from a WKB string.

After successful read the wkb argument will be at the position where the reading has stopped.

See also: fromWkt

Implemented in QgsCircularString, QgsCompoundCurve, QgsCurvePolygon, QgsGeometryCollection, QgsLineString, QgsPoint, QgsPolygon, QgsPolyhedralSurface, QgsTriangulatedSurface, and QgsTriangle.

◆ fromWkt()

virtual bool QgsAbstractGeometry::fromWkt ( const QString & wkt )

pure virtual

Sets the geometry from a WKT string.

See also: fromWkb

Implemented in QgsCircularString, QgsCompoundCurve, QgsCurvePolygon, QgsGeometryCollection, QgsLineString, QgsMultiCurve, QgsMultiLineString, QgsMultiPoint, QgsMultiPolygon, QgsMultiSurface, QgsPoint, QgsPolyhedralSurface, QgsTriangle, and QgsTriangulatedSurface.

◆ fuzzyDistanceEqual()

virtual bool QgsAbstractGeometry::fuzzyDistanceEqual	(	const QgsAbstractGeometry &	other,
		double	epsilon = `1e-8`
	)		const

pure virtual

Performs fuzzy distance comparison between this geometry and other using an epsilon.

Traditionally, the comparison is done by examining the specific values (such as x and y) that define the location of vertices in the geometry. It focuses on the numerical differences or relationships between these values. On the other hand, comparing distances between points considers the actual spatial separation or length between the points, regardless of their coordinate values. This comparison involves measuring the distance between two points using formulas like the distance formula. Here, it's the "distance comparison" (fuzzyDistanceEqual).

See also: fuzzyEqual; QgsGeometryUtilsBase::fuzzyEqual

Since: QGIS 3.36

Implemented in QgsCircularString, QgsCompoundCurve, QgsCurvePolygon, QgsGeometryCollection, QgsLineString, QgsPoint, QgsPolyhedralSurface, and QgsTriangulatedSurface.

◆ fuzzyEqual()

virtual bool QgsAbstractGeometry::fuzzyEqual	(	const QgsAbstractGeometry &	other,
		double	epsilon = `1e-8`
	)		const

pure virtual

Performs fuzzy comparison between this geometry and other using an epsilon.

The comparison is done by examining the specific values (such as x and y) that define the location of vertices in the geometry.

See also: fuzzyDistanceEqual; QgsGeometryUtilsBase::fuzzyDistanceEqual

Since: QGIS 3.36

Implemented in QgsCircularString, QgsCompoundCurve, QgsCurvePolygon, QgsGeometryCollection, QgsLineString, QgsPoint, QgsPolyhedralSurface, and QgsTriangulatedSurface.

◆ geometryType()

virtual QString QgsAbstractGeometry::geometryType ( ) const

pure virtual

Returns a unique string representing the geometry type.

See also: wkbType; wktTypeStr

Implemented in QgsCircularString, QgsCompoundCurve, QgsCurvePolygon, QgsGeometryCollection, QgsLineString, QgsMultiCurve, QgsMultiLineString, QgsMultiPoint, QgsMultiPolygon, QgsMultiSurface, QgsPoint, QgsPolygon, QgsPolyhedralSurface, QgsTriangle, and QgsTriangulatedSurface.

◆ hasChildGeometries()

bool QgsAbstractGeometry::hasChildGeometries ( ) const

protectedvirtual

Returns whether the geometry has any child geometries (false for point / curve, true otherwise)

Note: used for vertex_iterator implementation

Definition at line 403 of file qgsabstractgeometry.cpp.

◆ hasCurvedSegments()

bool QgsAbstractGeometry::hasCurvedSegments ( ) const

virtual

Returns true if the geometry contains curved segments.

Reimplemented in QgsPolyhedralSurface, QgsCircularString, QgsCompoundCurve, QgsCurvePolygon, and QgsGeometryCollection.

Definition at line 421 of file qgsabstractgeometry.cpp.

◆ insertVertex()

virtual bool QgsAbstractGeometry::insertVertex	(	QgsVertexId	position,
		const QgsPoint &	vertex
	)

pure virtual

Inserts a vertex into the geometry.

Parameters

position	vertex id for position of inserted vertex
vertex	vertex to insert

Returns: true if insert was successful

See also: moveVertex; deleteVertex

Implemented in QgsCircularString, QgsCompoundCurve, QgsCurvePolygon, QgsGeometryCollection, QgsLineString, QgsPoint, QgsPolyhedralSurface, QgsTriangle, and QgsTriangulatedSurface.

◆ is3D()

bool QgsAbstractGeometry::is3D ( ) const

inline

Returns true if the geometry is 3D and contains a z-value.

See also: isMeasure

Definition at line 250 of file qgsabstractgeometry.h.

◆ isEmpty()

bool QgsAbstractGeometry::isEmpty ( ) const

virtual

Returns true if the geometry is empty.

Reimplemented in QgsCircularString, QgsCompoundCurve, QgsCurvePolygon, QgsGeometryCollection, QgsLineString, QgsPoint, and QgsPolyhedralSurface.

Definition at line 414 of file qgsabstractgeometry.cpp.

◆ isMeasure()

bool QgsAbstractGeometry::isMeasure ( ) const

inline

Returns true if the geometry contains m values.

See also: is3D

Definition at line 259 of file qgsabstractgeometry.h.

◆ isValid()

virtual bool QgsAbstractGeometry::isValid	(	QString &	error,
		Qgis::GeometryValidityFlags	flags = `Qgis::GeometryValidityFlags()`
	)		const

pure virtual

Checks validity of the geometry, and returns true if the geometry is valid.

Parameters

error	will be set to the validity error message
flags	indicates optional flags which control the type of validity checking performed (corresponding to Qgis::GeometryValidityFlags).

Returns: true if geometry is valid

Since: QGIS 3.8

Implemented in QgsCircularString, QgsCompoundCurve, QgsCurve, QgsGeometryCollection, QgsLineString, QgsMultiPoint, QgsPoint, QgsPolyhedralSurface, and QgsSurface.

◆ length()

double QgsAbstractGeometry::length ( ) const

virtual

Returns the planar, 2-dimensional length of the geometry.

Warning: QgsAbstractGeometry objects are inherently Cartesian/planar geometries, and the length returned by this method is calculated using strictly Cartesian mathematics. In contrast, the QgsDistanceArea class exposes methods for calculating the lengths of geometries using geodesic calculations which account for the curvature of the Earth (or any other celestial body).

See also: area(); perimeter()

Reimplemented in QgsCircularString, QgsCompoundCurve, QgsGeometryCollection, and QgsLineString.

Definition at line 197 of file qgsabstractgeometry.cpp.

◆ moveVertex()

virtual bool QgsAbstractGeometry::moveVertex	(	QgsVertexId	position,
		const QgsPoint &	newPos
	)

pure virtual

Moves a vertex within the geometry.

Parameters

position	vertex id for vertex to move
newPos	new position of vertex

Returns: true if move was successful

See also: insertVertex; deleteVertex

Implemented in QgsCircularString, QgsCompoundCurve, QgsCurvePolygon, QgsGeometryCollection, QgsLineString, QgsPoint, QgsPolyhedralSurface, and QgsTriangle.

◆ nCoordinates()

int QgsAbstractGeometry::nCoordinates ( ) const

virtual

Returns the number of nodes contained in the geometry.

Reimplemented in QgsCurvePolygon, QgsGeometryCollection, QgsLineString, QgsMultiPoint, QgsPoint, and QgsPolyhedralSurface.

Definition at line 181 of file qgsabstractgeometry.cpp.

◆ nextVertex()

virtual bool QgsAbstractGeometry::nextVertex	(	QgsVertexId &	id,
		QgsPoint &	vertex
	)		const

pure virtual

Returns next vertex id and coordinates.

Parameters

id	initial value should be the starting vertex id. The next vertex id will be stored in this variable if found.
vertex	container for found node

Returns: false if at end

Implemented in QgsCurve, QgsCurvePolygon, QgsGeometryCollection, QgsPoint, and QgsPolyhedralSurface.

◆ normalize()

virtual void QgsAbstractGeometry::normalize ( )

pure virtual

Reorganizes the geometry into a normalized form (or "canonical" form).

Polygon rings will be rearranged so that their starting vertex is the lower left and ring orientation follows the right hand rule, collections are ordered by geometry type, and other normalization techniques are applied. The resultant geometry will be geometrically equivalent to the original geometry.

Since: QGIS 3.20

Implemented in QgsCurve, QgsCurvePolygon, QgsGeometryCollection, QgsPoint, QgsPolyhedralSurface, and QgsTriangulatedSurface.

◆ operator!=()

virtual bool QgsAbstractGeometry::operator!= ( const QgsAbstractGeometry & other ) const

pure virtual

Implemented in QgsCurve, QgsCurvePolygon, QgsGeometryCollection, QgsPoint, QgsPolyhedralSurface, QgsTriangle, and QgsTriangulatedSurface.

◆ operator=()

QgsAbstractGeometry & QgsAbstractGeometry::operator= ( const QgsAbstractGeometry & geom )

Definition at line 33 of file qgsabstractgeometry.cpp.

◆ operator==()

virtual bool QgsAbstractGeometry::operator== ( const QgsAbstractGeometry & other ) const

pure virtual

Implemented in QgsCurve, QgsCurvePolygon, QgsGeometryCollection, QgsPoint, QgsPolyhedralSurface, QgsTriangle, and QgsTriangulatedSurface.

◆ partCount()

virtual int QgsAbstractGeometry::partCount ( ) const

pure virtual

Returns count of parts contained in the geometry.

See also: vertexCount; ringCount

Implemented in QgsCurve, QgsCurvePolygon, QgsGeometryCollection, QgsPoint, and QgsPolyhedralSurface.

◆ parts() [1/2]

QgsGeometryPartIterator QgsAbstractGeometry::parts ( )

Returns Java-style iterator for traversal of parts of the geometry.

This iterator can safely be used to modify parts of the geometry.

Example

# print the WKT representation of each part in a multi-point geometry
geometry = QgsMultiPoint.fromWkt( 'MultiPoint( 0 0, 1 1, 2 2)' )
for part in geometry.parts():
    print(part.asWkt())
 
# single part geometries only have one part - this loop will iterate once only
geometry = QgsLineString.fromWkt( 'LineString( 0 0, 10 10 )' )
for part in geometry.parts():
    print(part.asWkt())
 
# parts can be modified during the iteration
geometry = QgsMultiPoint.fromWkt( 'MultiPoint( 0 0, 1 1, 2 2)' )
for part in geometry.parts():
    part.transform(ct)
 
# part iteration can also be combined with vertex iteration
geometry = QgsMultiPolygon.fromWkt( 'MultiPolygon((( 0 0, 0 10, 10 10, 10 0, 0 0 ),( 5 5, 5 6, 6 6, 6 5, 5 5)),((20 2, 22 2, 22 4, 20 4, 20 2)))' )
for part in geometry.parts():
    for v in part.vertices():
        print(v.x(), v.y())

See also: vertices()

Since: QGIS 3.6

Definition at line 344 of file qgsabstractgeometry.cpp.

◆ parts() [2/2]

QgsGeometryConstPartIterator QgsAbstractGeometry::parts ( ) const

Returns Java-style iterator for traversal of parts of the geometry.

This iterator returns read-only references to parts and cannot be used to modify the parts.

Note: Not available in Python bindings

Since: QGIS 3.6

Definition at line 349 of file qgsabstractgeometry.cpp.

◆ parts_begin()

part_iterator QgsAbstractGeometry::parts_begin ( )

inline

Returns STL-style iterator pointing to the first part of the geometry.

See also: parts_end(); parts()

Since: QGIS 3.6

Definition at line 880 of file qgsabstractgeometry.h.

◆ parts_end()

QgsAbstractGeometry::part_iterator QgsAbstractGeometry::parts_end ( )

Returns STL-style iterator pointing to the imaginary part after the last part of the geometry.

See also: parts_begin(); parts()

Since: QGIS 3.6

Definition at line 338 of file qgsabstractgeometry.cpp.

◆ perimeter()

double QgsAbstractGeometry::perimeter ( ) const

virtual

Returns the planar, 2-dimensional perimeter of the geometry.

Warning: QgsAbstractGeometry objects are inherently Cartesian/planar geometries, and the perimeter returned by this method is calculated using strictly Cartesian mathematics. In contrast, the QgsDistanceArea class exposes methods for calculating the perimeters of geometries using geodesic calculations which account for the curvature of the Earth (or any other celestial body).

See also: area(); length()

Reimplemented in QgsCurvePolygon, QgsGeometryCollection, and QgsPolyhedralSurface.

Definition at line 202 of file qgsabstractgeometry.cpp.

◆ removeDuplicateNodes()

virtual bool QgsAbstractGeometry::removeDuplicateNodes	(	double	epsilon = `4 *std::numeric_limits< double >::epsilon()`,
		bool	useZValues = `false`
	)

pure virtual

Removes duplicate nodes from the geometry, wherever removing the nodes does not result in a degenerate geometry.

The epsilon parameter specifies the tolerance for coordinates when determining that vertices are identical.

By default, z values are not considered when detecting duplicate nodes. E.g. two nodes with the same x and y coordinate but different z values will still be considered duplicate and one will be removed. If useZValues is true, then the z values are also tested and nodes with the same x and y but different z will be maintained.

Note that duplicate nodes are not tested between different parts of a multipart geometry. E.g. a multipoint geometry with overlapping points will not be changed by this method.

The function will return true if nodes were removed, or false if no duplicate nodes were found.

Implemented in QgsCircularString, QgsCompoundCurve, QgsCurvePolygon, QgsGeometryCollection, QgsLineString, QgsPoint, and QgsPolyhedralSurface.

◆ ringCount()

virtual int QgsAbstractGeometry::ringCount ( int part = 0 ) const

pure virtual

Returns the number of rings of which this geometry is built.

Implemented in QgsCurve, QgsCurvePolygon, QgsGeometryCollection, QgsPolyhedralSurface, and QgsPoint.

◆ segmentize()

QgsAbstractGeometry * QgsAbstractGeometry::segmentize	(	double	tolerance = `M_PI / 180.`,
		SegmentationToleranceType	toleranceType = `MaximumAngle`
	)		const

virtual

Returns a version of the geometry without curves.

Caller takes ownership of the returned geometry.

Parameters

tolerance	segmentation tolerance
toleranceType	maximum segmentation angle or maximum difference between approximation and curve

Reimplemented in QgsCurve, QgsCurvePolygon, QgsGeometryCollection, and QgsPolyhedralSurface.

Definition at line 436 of file qgsabstractgeometry.cpp.

◆ segmentLength()

virtual double QgsAbstractGeometry::segmentLength ( QgsVertexId startVertex ) const

pure virtual

Returns the length of the segment of the geometry which begins at startVertex.

Warning: QgsAbstractGeometry objects are inherently Cartesian/planar geometries, and the lengths returned by this method are calculated using strictly Cartesian mathematics.

Implemented in QgsCircularString, QgsCompoundCurve, QgsCurvePolygon, QgsGeometryCollection, QgsLineString, QgsMultiPoint, QgsPoint, and QgsPolyhedralSurface.

◆ setZMTypeFromSubGeometry()

void QgsAbstractGeometry::setZMTypeFromSubGeometry	(	const QgsAbstractGeometry *	subggeom,
		Qgis::WkbType	baseGeomType
	)

protected

Updates the geometry type based on whether sub geometries contain z or m values.

Definition at line 76 of file qgsabstractgeometry.cpp.

◆ simplifiedTypeRef()

const QgsAbstractGeometry * QgsAbstractGeometry::simplifiedTypeRef ( ) const

virtual

Returns a reference to the simplest lossless representation of this geometry, e.g.

if the geometry is a multipart geometry type with a single member geometry, a reference to that part will be returned.

This method employs the following logic:

For multipart geometries containing a single part only a direct reference to that part will be returned.
For compound curve geometries containing a single curve only a direct reference to that curve will be returned.

This method returns a reference only, and does not involve any geometry cloning.

Note: Ownership of the returned geometry is NOT transferred, and remains with the original geometry object. Callers must take care to ensure that the original geometry object exists for the lifespan of the returned object.

Since: QGIS 3.20

Reimplemented in QgsCompoundCurve, and QgsGeometryCollection.

Definition at line 323 of file qgsabstractgeometry.cpp.

◆ simplifyByDistance()

virtual QgsAbstractGeometry * QgsAbstractGeometry::simplifyByDistance ( double tolerance ) const

pure virtual

Simplifies the geometry by applying the Douglas Peucker simplification by distance algorithm.

The caller takes ownership of the returned geometry. Curved geometries will be segmentized prior to simplification.

If a simplified geometry cannot be calculated nullptr will be returned.

The returned geometry may be invalid and contain self-intersecting rings.

Since: QGIS 3.38

Implemented in QgsCircularString, QgsCompoundCurve, QgsCurvePolygon, QgsGeometryCollection, QgsLineString, QgsMultiCurve, QgsMultiLineString, QgsMultiPoint, QgsMultiPolygon, QgsMultiSurface, QgsPoint, and QgsPolyhedralSurface.

◆ snappedToGrid()

virtual QgsAbstractGeometry * QgsAbstractGeometry::snappedToGrid	(	double	hSpacing,
		double	vSpacing,
		double	dSpacing = `0`,
		double	mSpacing = `0`,
		bool	removeRedundantPoints = `false`
	)		const

pure virtual

Makes a new geometry with all the points or vertices snapped to the closest point of the grid.

Ownership is transferred to the caller.

If the gridified geometry could not be calculated nullptr will be returned. It may generate an invalid geometry (in some corner cases). It can also be thought as rounding the edges and it may be useful for removing errors.

Example:

geometry.snappedToGrid(1, 1)

In this case we use a 2D grid of 1x1 to gridify. In this case, it can be thought like rounding the x and y of all the points/vertices to full units (remove all decimals).

Parameters

hSpacing	Horizontal spacing of the grid (x axis). 0 to disable.
vSpacing	Vertical spacing of the grid (y axis). 0 to disable.
dSpacing	Depth spacing of the grid (z axis). 0 (default) to disable.
mSpacing	Custom dimension spacing of the grid (m axis). 0 (default) to disable.
removeRedundantPoints	if `true`, then points which are redundant (e.g. they represent mid points on a straight line segment) will be skipped (since QGIS 3.38)

Implemented in QgsCircularString, QgsCompoundCurve, QgsCurvePolygon, QgsGeometryCollection, QgsLineString, QgsPoint, QgsPolyhedralSurface, and QgsTriangulatedSurface.

◆ sortIndex()

int QgsAbstractGeometry::sortIndex ( ) const

protected

Returns the sort index for the geometry, used in the compareTo() method to compare geometries of different types.

Since: QGIS 3.20

Definition at line 365 of file qgsabstractgeometry.cpp.

◆ swapXy()

virtual void QgsAbstractGeometry::swapXy ( )

pure virtual

Swaps the x and y coordinates from the geometry.

This can be used to repair geometries which have accidentally had their latitude and longitude coordinates reversed.

Since: QGIS 3.2

Implemented in QgsCircularString, QgsCompoundCurve, QgsCurvePolygon, QgsGeometryCollection, QgsLineString, QgsPoint, and QgsPolyhedralSurface.

◆ toCurveType()

virtual QgsAbstractGeometry * QgsAbstractGeometry::toCurveType ( ) const

pure virtual

Returns the geometry converted to the more generic curve type.

E.g. QgsLineString -> QgsCompoundCurve, QgsPolygon -> QgsCurvePolygon, QgsMultiLineString -> QgsMultiCurve, QgsMultiPolygon -> QgsMultiSurface

Returns: the converted geometry. Caller takes ownership

Implemented in QgsCurve, QgsCurvePolygon, QgsGeometryCollection, QgsLineString, QgsMultiCurve, QgsMultiLineString, QgsMultiPoint, QgsMultiPolygon, QgsMultiSurface, QgsPoint, QgsPolygon, QgsPolyhedralSurface, and QgsTriangle.

◆ transform() [1/3]

virtual void QgsAbstractGeometry::transform	(	const QgsCoordinateTransform &	ct,
		Qgis::TransformDirection	d = `Qgis::TransformDirection::Forward`,
		bool	transformZ = `false`
	)

pure virtual

Transforms the geometry using a coordinate transform.

Parameters

ct	coordinate transform
d	transformation direction
transformZ	set to `true` to also transform z coordinates. This requires that the z coordinates in the geometry represent height relative to the vertical datum of the source CRS (generally ellipsoidal heights) and are expressed in its vertical units (generally meters). If `false`, then z coordinates will not be changed by the transform.

Implemented in QgsCircularString, QgsCompoundCurve, QgsCurvePolygon, QgsGeometryCollection, QgsLineString, QgsPoint, and QgsPolyhedralSurface.

◆ transform() [2/3]

virtual void QgsAbstractGeometry::transform	(	const QTransform &	t,
		double	zTranslate = `0.0`,
		double	zScale = `1.0`,
		double	mTranslate = `0.0`,
		double	mScale = `1.0`
	)

pure virtual

Transforms the x and y components of the geometry using a QTransform object t.

Optionally, the geometry's z values can be scaled via zScale and translated via zTranslate. Similarly, m-values can be scaled via mScale and translated via mTranslate.

Implemented in QgsCircularString, QgsCompoundCurve, QgsCurvePolygon, QgsGeometryCollection, QgsLineString, QgsPoint, and QgsPolyhedralSurface.

◆ transform() [3/3]

virtual bool QgsAbstractGeometry::transform	(	QgsAbstractGeometryTransformer *	transformer,
		QgsFeedback *	feedback = `nullptr`
	)

pure virtual

Transforms the vertices from the geometry in place, using the specified geometry transformer object.

Depending on the transformer used, this may result in an invalid geometry.

The optional feedback argument can be used to cancel the transformation before it completes. If this is done, the geometry will be left in a semi-transformed state.

Returns: true if the geometry was successfully transformed.

Since: QGIS 3.18

Implemented in QgsCircularString, QgsCompoundCurve, QgsCurvePolygon, QgsGeometryCollection, QgsLineString, QgsPoint, and QgsPolyhedralSurface.

◆ transformVertices()

void QgsAbstractGeometry::transformVertices ( const std::function< QgsPoint(const QgsPoint &) > & transform )

virtual

Transforms the vertices from the geometry in place, applying the transform function to every vertex.

Depending on the transform used, this may result in an invalid geometry.

Transform functions are not permitted to alter the dimensionality of vertices. If a transform which adds (or removes) z/m values is desired, first call the corresponding addZValue() or addMValue() function to change the geometry's dimensionality and then transform.

Note: Not available in Python bindings

Since: QGIS 3.4

Reimplemented in QgsCircularString, QgsCompoundCurve, QgsCurvePolygon, QgsGeometryCollection, QgsLineString, QgsPoint, and QgsPolyhedralSurface.

Definition at line 333 of file qgsabstractgeometry.cpp.

◆ vertexAngle()

virtual double QgsAbstractGeometry::vertexAngle ( QgsVertexId vertex ) const

pure virtual

Returns approximate angle at a vertex.

This is usually the average angle between adjacent segments, and can be pictured as the orientation of a line following the curvature of the geometry at the specified vertex.

Parameters

vertex the vertex id

Returns: rotation in radians, clockwise from north

Implemented in QgsCircularString, QgsCompoundCurve, QgsCurvePolygon, QgsGeometryCollection, QgsLineString, QgsPoint, and QgsPolyhedralSurface.

◆ vertexAt()

virtual QgsPoint QgsAbstractGeometry::vertexAt ( QgsVertexId id ) const

pure virtual

Returns the point corresponding to a specified vertex id.

Implemented in QgsCurve, QgsCurvePolygon, QgsGeometryCollection, QgsPolyhedralSurface, and QgsPoint.

◆ vertexCount()

virtual int QgsAbstractGeometry::vertexCount	(	int	part = `0`,
		int	ring = `0`
	)		const

pure virtual

Returns the number of vertices of which this geometry is built.

Implemented in QgsCurve, QgsCurvePolygon, QgsGeometryCollection, QgsPolyhedralSurface, and QgsPoint.

◆ vertexNumberFromVertexId()

virtual int QgsAbstractGeometry::vertexNumberFromVertexId ( QgsVertexId id ) const

pure virtual

Returns the vertex number corresponding to a vertex id.

The vertex numbers start at 0, so a return value of 0 corresponds to the first vertex.

Returns -1 if a corresponding vertex could not be found.

Implemented in QgsCurve, QgsCurvePolygon, QgsGeometryCollection, QgsMultiPoint, QgsPoint, and QgsPolyhedralSurface.

◆ vertices()

QgsVertexIterator QgsAbstractGeometry::vertices ( ) const

Returns a read-only, Java-style iterator for traversal of vertices of all the geometry, including all geometry parts and rings.

Warning: The iterator returns a copy of individual vertices, and accordingly geometries cannot be modified using the iterator. See transformVertices() for a safe method to modify vertices "in-place".

Example

# print the x and y coordinate for each vertex in a LineString
geometry = QgsLineString.fromWkt( 'LineString( 0 0, 1 1, 2 2)' )
for v in geometry.vertices():
    print(v.x(), v.y())
 
# vertex iteration includes all parts and rings
geometry = QgsMultiPolygon.fromWkt( 'MultiPolygon((( 0 0, 0 10, 10 10, 10 0, 0 0 ),( 5 5, 5 6, 6 6, 6 5, 5 5)),((20 2, 22 2, 22 4, 20 4, 20 2)))' )
for v in geometry.vertices():
    print(v.x(), v.y())

See also: parts()

Definition at line 360 of file qgsabstractgeometry.cpp.

◆ vertices_begin()

vertex_iterator QgsAbstractGeometry::vertices_begin ( ) const

inline

Returns STL-style iterator pointing to the first vertex of the geometry.

See also: vertices_end(); vertices()

Definition at line 1023 of file qgsabstractgeometry.h.

◆ vertices_end()

vertex_iterator QgsAbstractGeometry::vertices_end ( ) const

inline

Returns STL-style iterator pointing to the imaginary vertex after the last vertex of the geometry.

See also: vertices_begin(); vertices()

Definition at line 1035 of file qgsabstractgeometry.h.

◆ wkbSize()

virtual int QgsAbstractGeometry::wkbSize ( QgsAbstractGeometry::WkbFlags flags = QgsAbstractGeometry::WkbFlags() ) const

pure virtual

Returns the length of the QByteArray returned by asWkb()

The optional flags argument specifies flags controlling WKB export behavior

Since: QGIS 3.16

Implemented in QgsCircularString, QgsCompoundCurve, QgsCurvePolygon, QgsGeometryCollection, QgsLineString, QgsPoint, QgsPolygon, and QgsPolyhedralSurface.

◆ wkbType()

Qgis::WkbType QgsAbstractGeometry::wkbType ( ) const

inline

Returns the WKB type of the geometry.

See also: geometryType; wktTypeStr

Definition at line 237 of file qgsabstractgeometry.h.

◆ wktTypeStr()

QString QgsAbstractGeometry::wktTypeStr ( ) const

Returns the WKT type string of the geometry.

See also: geometryType; wkbType

Definition at line 212 of file qgsabstractgeometry.cpp.

Friends And Related Symbol Documentation

◆ TestQgsGeometry

friend class TestQgsGeometry

friend

Definition at line 1181 of file qgsabstractgeometry.h.

Member Data Documentation

◆ mWkbType

Qgis::WkbType QgsAbstractGeometry::mWkbType = Qgis::WkbType::Unknown

protected

Definition at line 1155 of file qgsabstractgeometry.h.

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

/build/qgis-3.41.0+git20241201+3c143d501a8+99sid/src/core/geometry/qgsabstractgeometry.h
/build/qgis-3.41.0+git20241201+3c143d501a8+99sid/src/core/geometry/qgsabstractgeometry.cpp

Classes

Public Types

Public Member Functions

Protected Member Functions

Protected Attributes

Friends

Detailed Description

Member Typedef Documentation

◆ WkbFlags

Member Enumeration Documentation

◆ AxisOrder

◆ SegmentationToleranceType

◆ WkbFlag

Constructor & Destructor Documentation

◆ QgsAbstractGeometry() [1/2]

◆ ~QgsAbstractGeometry()

◆ QgsAbstractGeometry() [2/2]

Member Function Documentation

◆ addMValue()

◆ addZValue()

◆ adjacentVertices()

◆ area()

◆ asGml2()

◆ asGml3()

◆ asJson()

◆ asJsonObject()

◆ asKml()

◆ asQPainterPath()

◆ asWkb()

◆ asWkt()

◆ boundary()

◆ boundingBox()

◆ boundingBox3D()

◆ boundingBoxIntersects() [1/2]

◆ boundingBoxIntersects() [2/2]

◆ calculateBoundingBox()

◆ calculateBoundingBox3D()

◆ centroid()

◆ childCount()

◆ childGeometry()

◆ childPoint()

◆ clear()

◆ clearCache()

◆ clone()

◆ closestSegment()

◆ compareTo()

◆ compareToSameClass()

◆ const_parts_begin()

◆ const_parts_end()

◆ convertTo()

◆ coordinateSequence()

◆ createEmptyWithSameType()

◆ deleteVertex()

◆ dimension()

◆ draw()

◆ dropMValue()

◆ dropZValue()

◆ filterVertices()

◆ fromWkb()

◆ fromWkt()

◆ fuzzyDistanceEqual()

◆ fuzzyEqual()

◆ geometryType()

◆ hasChildGeometries()

◆ hasCurvedSegments()

◆ insertVertex()

◆ is3D()

◆ isEmpty()

◆ isMeasure()

◆ isValid()

◆ length()

◆ moveVertex()

◆ nCoordinates()

◆ nextVertex()

◆ normalize()

◆ operator!=()

◆ operator=()

◆ operator==()

◆ partCount()

◆ parts() [1/2]