Polygon geometry type. More...

#include <qgspolygon.h>

Inheritance diagram for QgsPolygon:

[legend]

Public Member Functions
	QgsPolygon ()
	Constructor for an empty polygon geometry.

	QgsPolygon (QgsLineString exterior, const QList< QgsLineString > &rings=QList< QgsLineString * >())
	Constructor for QgsPolygon, with the specified exterior ring and interior rings.

void	addInteriorRing (QgsCurve *ring) override
	Adds an interior ring to the geometry (takes ownership)

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

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

QgsAbstractGeometry *	boundary () const override
	Returns the closure of the combinatorial boundary of the geometry (ie the topological boundary of the geometry).

void	clear () override
	Clears the geometry, ie reset it to a null geometry.

QgsPolygon *	clone () const override
	Clones the geometry by performing a deep copy.

QgsPolygon *	createEmptyWithSameType () const override
	Creates a new geometry with the same class and same WKB type as the original and transfers ownership.

bool	fromWkb (QgsConstWkbPtr &wkb) override
	Sets the geometry from a WKB string.

QString	geometryType () const override
	Returns a unique string representing the geometry type.

double	pointDistanceToBoundary (double x, double y) const
	Returns the distance from a point to the boundary of the polygon (either the exterior ring or any closer interior rings).

void	setExteriorRing (QgsCurve *ring) override
	Sets the exterior ring of the polygon.

QgsPolygon *	surfaceToPolygon () const override
	Gets a polygon representation of this surface.

QgsCurvePolygon *	toCurveType () const override
	Returns the geometry converted to the more generic curve type QgsCurvePolygon.

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

Public Member Functions inherited from QgsCurvePolygon
	QgsCurvePolygon ()

	QgsCurvePolygon (const QgsCurvePolygon &p)

	~QgsCurvePolygon () override

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

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

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

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

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

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

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

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

QPainterPath	asQPainterPath () const override
	Returns the geometry represented as a QPainterPath.

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

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

QgsCoordinateSequence	coordinateSequence () const override
	Retrieves the sequence of geometries, rings and nodes.

bool	deleteVertex (QgsVertexId position) override
	Deletes a vertex within the geometry.

int	dimension () const override
	Returns the inherent dimension of the geometry.

void	draw (QPainter &p) const override
	Draws the geometry using the specified QPainter.

bool	dropMValue () override
	Drops any measure values which exist in the geometry.

bool	dropZValue () override
	Drops any z-dimensions which exist in the geometry.

QgsCurve *	exteriorRing ()
	Returns a non-const pointer to the curve polygon's exterior ring.

const QgsCurve *	exteriorRing () const
	Returns the curve polygon's exterior ring.

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

void	forceClockwise ()
	Forces the polygon to respect the exterior ring is clockwise, interior rings are counter-clockwise convention.

void	forceCounterClockwise ()
	Forces the polygon to respect the exterior ring is counter-clockwise, interior rings are clockwise convention.

void	forceRHR ()
	Forces the geometry to respect the Right-Hand-Rule, in which the area that is bounded by the polygon is to the right of the boundary.

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

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

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

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

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

QgsCurve *	interiorRing (int i)
	Retrieves an interior ring from the curve polygon.

const QgsCurve *	interiorRing (int i) const
	Retrieves an interior ring from the curve polygon.

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

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

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

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

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

int	numInteriorRings () const
	Returns the number of interior rings contained with the curve polygon.

bool	operator!= (const QgsAbstractGeometry &other) const override

QgsCurvePolygon &	operator= (const QgsCurvePolygon &p)

bool	operator== (const QgsAbstractGeometry &other) const override

int	partCount () const override
	Returns count of parts contained in the geometry.

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

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

bool	removeInteriorRing (int ringIndex)
	Removes an interior ring from the polygon.

void	removeInteriorRings (double minimumAllowedArea=-1)
	Removes the interior rings from the polygon.

void	removeInvalidRings ()
	Removes any interior rings which are not valid from the polygon.

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

double	roundness () const
	Returns the roundness of the curve polygon.

QgsAbstractGeometry *	segmentize (double tolerance=M_PI_2/90, SegmentationToleranceType toleranceType=MaximumAngle) const override
	Returns a geometry without curves.

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

void	setInteriorRings (const QVector< QgsCurve * > &rings)
	Sets all interior rings (takes ownership)

QgsCurvePolygon *	simplifyByDistance (double tolerance) const override
	Simplifies the geometry by applying the Douglas Peucker simplification by distance algorithm.

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

void	swapXy () override
	Swaps the x and y coordinates from the geometry.

virtual QgsPolygon *	toPolygon (double tolerance=M_PI_2/90, SegmentationToleranceType toleranceType=MaximumAngle) const
	Returns a new polygon geometry corresponding to a segmentized approximation of the curve.

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

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

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

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

double	vertexAngle (QgsVertexId vertex) const override
	Returns approximate rotation angle for a vertex.

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

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

int	vertexNumberFromVertexId (QgsVertexId id) const override
	Returns the vertex number corresponding to a vertex id.

Public Member Functions inherited from QgsSurface
QgsBox3D	boundingBox3D () const override
	Returns the 3D bounding box for the geometry.

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

Public Member Functions inherited from QgsAbstractGeometry
	QgsAbstractGeometry ()=default

	QgsAbstractGeometry (const QgsAbstractGeometry &geom)

virtual	~QgsAbstractGeometry ()=default

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

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

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 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.

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

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

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

QgsAbstractGeometry &	operator= (const QgsAbstractGeometry &geom)

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

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.

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

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

Static Public Member Functions
static const QgsPolygon *	cast (const QgsAbstractGeometry *geom)
	Cast the geom to a QgsPolygonV2.

Static Public Member Functions inherited from QgsCurvePolygon
static const QgsCurvePolygon *	cast (const QgsAbstractGeometry *geom)
	Cast the geom to a QgsCurvePolygon.

Static Public Member Functions inherited from QgsSurface
static const QgsSurface *	cast (const QgsAbstractGeometry *geom)
	Cast the geom to a QgsSurface.

Friends
class	QgsCurvePolygon

Additional Inherited Members
Public Types inherited from QgsAbstractGeometry
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

Protected Member Functions inherited from QgsCurvePolygon
QgsBox3D	calculateBoundingBox3D () const override
	Calculates the minimal 3D bounding box for the geometry.

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

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

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

Protected Member Functions inherited from QgsSurface
void	clearCache () const override
	Clears any cached parameters associated with the geometry, e.g., bounding boxes.

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

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

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 inherited from QgsCurvePolygon
std::unique_ptr< QgsCurve >	mExteriorRing

QVector< QgsCurve * >	mInteriorRings

Protected Attributes inherited from QgsSurface
QgsBox3D	mBoundingBox

bool	mHasCachedValidity = false

QString	mValidityFailureReason

Protected Attributes inherited from QgsAbstractGeometry
Qgis::WkbType	mWkbType = Qgis::WkbType::Unknown

Detailed Description

Polygon geometry type.

Definition at line 32 of file qgspolygon.h.

Constructor & Destructor Documentation

◆ QgsPolygon() [1/2]

QgsPolygon::QgsPolygon ( )

Constructor for an empty polygon geometry.

Definition at line 25 of file qgspolygon.cpp.

◆ QgsPolygon() [2/2]

QgsPolygon::QgsPolygon	(	QgsLineString *	exterior,
		const QList< QgsLineString * > &	rings = `QList< QgsLineString * >()`
	)

Constructor for QgsPolygon, with the specified exterior ring and interior rings.

Ownership of exterior and rings is transferred to the polygon.

Since: QGIS 3.14

Member Function Documentation

◆ addInteriorRing()

void QgsPolygon::addInteriorRing ( QgsCurve * ring )

overridevirtual

Adds an interior ring to the geometry (takes ownership)

Reimplemented from QgsCurvePolygon.

Reimplemented in QgsTriangle.

Definition at line 235 of file qgspolygon.cpp.

◆ asWkb()

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

overridevirtual

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()

Reimplemented from QgsCurvePolygon.

Definition at line 141 of file qgspolygon.cpp.

◆ asWkt()

QString QgsPolygon::asWkt ( int precision = 17 ) const

overridevirtual

Returns a WKT representation of the geometry.

Parameters

precision number of decimal places for coordinates

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

Reimplemented from QgsCurvePolygon.

Definition at line 188 of file qgspolygon.cpp.

◆ boundary()

QgsAbstractGeometry * QgsPolygon::boundary ( ) const

overridevirtual

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.

Reimplemented from QgsCurvePolygon.

Reimplemented in QgsTriangle.

Definition at line 301 of file qgspolygon.cpp.

◆ cast()

static const QgsPolygon * QgsPolygon::cast ( const QgsAbstractGeometry * geom )

inlinestatic

Cast the geom to a QgsPolygonV2.

Should be used by qgsgeometry_cast<QgsPolygon *>( geometry ).

Note: Not available in Python. Objects will be automatically be converted to the appropriate target type.

Definition at line 87 of file qgspolygon.h.

◆ clear()

void QgsPolygon::clear ( )

overridevirtual

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

Reimplemented from QgsCurvePolygon.

Reimplemented in QgsTriangle.

Definition at line 59 of file qgspolygon.cpp.

◆ clone()

QgsPolygon * QgsPolygon::clone ( ) const

overridevirtual

Clones the geometry by performing a deep copy.

Reimplemented from QgsCurvePolygon.

Reimplemented in QgsTriangle.

Definition at line 54 of file qgspolygon.cpp.

◆ createEmptyWithSameType()

QgsPolygon * QgsPolygon::createEmptyWithSameType ( ) const

overridevirtual

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()

Reimplemented from QgsCurvePolygon.

Reimplemented in QgsTriangle.

Definition at line 47 of file qgspolygon.cpp.

◆ fromWkb()

bool QgsPolygon::fromWkb ( QgsConstWkbPtr & wkb )

overridevirtual

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

Reimplemented from QgsCurvePolygon.

Reimplemented in QgsTriangle.

Definition at line 65 of file qgspolygon.cpp.

◆ geometryType()

QString QgsPolygon::geometryType ( ) const

overridevirtual

Returns a unique string representing the geometry type.

See also: wkbType; wktTypeStr

Reimplemented from QgsCurvePolygon.

Reimplemented in QgsTriangle.

Definition at line 42 of file qgspolygon.cpp.

◆ pointDistanceToBoundary()

double QgsPolygon::pointDistanceToBoundary	(	double	x,
		double	y
	)		const

Returns the distance from a point to the boundary of the polygon (either the exterior ring or any closer interior rings).

The returned distance will be negative if the point lies outside the polygon.

Definition at line 324 of file qgspolygon.cpp.

◆ setExteriorRing()

void QgsPolygon::setExteriorRing ( QgsCurve * ring )

overridevirtual

Sets the exterior ring of the polygon.

The CurvePolygon type will be updated to match the dimensionality of the exterior ring. For instance, setting a 2D exterior ring on a 3D CurvePolygon will drop the z dimension from the CurvePolygon and all interior rings.

Parameters

ring	new exterior ring. Ownership is transferred to the CurvePolygon.

See also: setInteriorRings(); exteriorRing()

Reimplemented from QgsCurvePolygon.

Reimplemented in QgsTriangle.

Definition at line 266 of file qgspolygon.cpp.

◆ surfaceToPolygon()

QgsPolygon * QgsPolygon::surfaceToPolygon ( ) const

overridevirtual

Gets a polygon representation of this surface.

Ownership is transferred to the caller.

Reimplemented from QgsCurvePolygon.

Reimplemented in QgsTriangle.

Definition at line 358 of file qgspolygon.cpp.

◆ toCurveType()

QgsCurvePolygon * QgsPolygon::toCurveType ( ) const

overridevirtual

Returns the geometry converted to the more generic curve type QgsCurvePolygon.

Returns: the converted geometry. Caller takes ownership

Reimplemented from QgsCurvePolygon.

Reimplemented in QgsTriangle.

Definition at line 363 of file qgspolygon.cpp.

◆ wkbSize()

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

overridevirtual

Returns the length of the QByteArray returned by asWkb()

The optional flags argument specifies flags controlling WKB export behavior

Since: QGIS 3.16

Reimplemented from QgsCurvePolygon.

Definition at line 124 of file qgspolygon.cpp.

Friends And Related Symbol Documentation

◆ QgsCurvePolygon

friend class QgsCurvePolygon

friend

Definition at line 116 of file qgspolygon.h.

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

/build/qgis-3.41.0+git20241119+45a0abf3bec+99sid/src/core/geometry/qgspolygon.h
/build/qgis-3.41.0+git20241119+45a0abf3bec+99sid/src/core/geometry/qgspolygon.cpp

Public Member Functions

Static Public Member Functions

Friends

Additional Inherited Members

Detailed Description

Constructor & Destructor Documentation

◆ QgsPolygon() [1/2]

◆ QgsPolygon() [2/2]

Member Function Documentation

◆ addInteriorRing()

◆ asWkb()

◆ asWkt()

◆ boundary()

◆ cast()

◆ clear()

◆ clone()

◆ createEmptyWithSameType()

◆ fromWkb()

◆ geometryType()

◆ pointDistanceToBoundary()

◆ setExteriorRing()

◆ surfaceToPolygon()

◆ toCurveType()

◆ wkbSize()

Friends And Related Symbol Documentation

◆ QgsCurvePolygon