Circular string geometry type. More...

#include <qgscircularstring.h>

Inheritance diagram for QgsCircularString:

[legend]

Public Member Functions
	QgsCircularString ()
	Constructs an empty circular string.
	QgsCircularString (const QgsPoint &p1, const QgsPoint &p2, const QgsPoint &p3)
	Constructs a circular string with a single arc passing through p1, p2 and p3.
	QgsCircularString (const QVector< double > &x, const QVector< double > &y, const QVector< double > &z=QVector< double >(), const QVector< double > &m=QVector< double >())
	Construct a circular string from arrays of coordinates.
void	addToPainterPath (QPainterPath &path) const override
	Adds a curve to a painter path.
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.
void	clear () override
	Clears the geometry, ie reset it to a null geometry.
QgsCircularString *	clone () const override
	Clones the geometry by performing a deep copy.
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.
QgsCircularString *	createEmptyWithSameType () const override
	Creates a new geometry with the same class and same WKB type as the original and transfers ownership.
QgsCircularString *	curveSubstring (double startDistance, double endDistance) const override
	Returns a new curve representing a substring of this curve.
QgsLineString *	curveToLine (double tolerance=M_PI_2/90, SegmentationToleranceType toleranceType=MaximumAngle) const override
	Returns a new line string geometry corresponding to a segmentized approximation of the curve.
bool	deleteVertex (QgsVertexId position) override
	Deletes a vertex within the geometry.
bool	deleteVertices (const QSet< QgsVertexId > &positions) override
	Deletes vertices within the geometry.
double	distanceBetweenVertices (QgsVertexId fromVertex, QgsVertexId toVertex) const override
	Returns the distance along the curve between two vertices.
void	draw (QPainter &p) const override
	Draws the geometry using the specified QPainter.
void	drawAsPolygon (QPainter &p) const override
	Draws the curve as a polygon on the specified QPainter.
QString	geometryType () const override
	Returns a unique string representing the geometry type.
bool	hasCurvedSegments () const override
	Returns `true` if the geometry contains curved segments.
int	indexOf (const QgsPoint &point) const final
	Returns the index of the first vertex matching the given point, or -1 if a matching vertex is not found.
bool	insertVertex (QgsVertexId position, const QgsPoint &vertex) override
	Inserts a vertex into the geometry.
QgsPoint *	interpolatePoint (double distance) const override
	Returns an interpolated point on the curve at the specified distance.
bool	isValid (QString &error, Qgis::GeometryValidityFlags flags=Qgis::GeometryValidityFlags()) const override
	Checks validity of the geometry, and returns `true` if the geometry is valid.
double	length () const override
	Returns the planar, 2-dimensional length of the geometry.
bool	pointAt (int node, QgsPoint &point, Qgis::VertexType &type) const override
	Returns the point and vertex type of a point within the curve.
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.
QgsCircularString *	reversed () const override
	Returns a reversed copy of the curve, where the direction of the curve has been flipped.
double	segmentLength (QgsVertexId startVertex) const override
	Returns the length of the segment of the geometry which begins at startVertex.
QgsAbstractGeometry *	simplifyByDistance (double tolerance) const override
	Simplifies the geometry by applying the Douglas Peucker simplification by distance algorithm.
QgsCircularString *	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.
std::tuple< std::unique_ptr< QgsCurve >, std::unique_ptr< QgsCurve > >	splitCurveAtVertex (int index) const final
	Splits the curve at the specified vertex index, returning two curves which represent the portion of the curve up to including the vertex at index, and the portion of the curve from the vertex at index (inclusive) to the end of the curve.
void	sumUpArea (double &sum) const override
	Sums up the area of the curve by iterating over the vertices (shoelace formula).
void	sumUpArea3D (double &sum) const override
	Sums up the 3d area of the curve by iterating over the vertices (shoelace formula).
double	vertexAngle (QgsVertexId vertex) const override
	Returns approximate angle at a vertex.
Public Member Functions inherited from QgsSimpleCurve
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	append (const QgsSimpleCurve *curve)
	Appends the contents of another simple curve to the end of this simple curve.
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.
void	clear () override
	Clears the geometry, ie reset it to a null geometry.
int	dimension () const override
	Returns the inherent dimension of the geometry.
bool	dropMValue () override
	Drops any measure values which exist in the geometry.
bool	dropZValue () override
	Drops any z-dimensions which exist in the geometry.
QgsPoint	endPoint () const override
	Returns the end point of the curve.
bool	equals (const QgsCurve &other) const override
	Checks whether this curve exactly equals another curve.
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.
bool	fromWkb (QgsConstWkbPtr &wkb) override
	Sets the geometry from a WKB string.
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	isEmpty () const override
	Returns `true` if the geometry is empty.
double	mAt (int index) const override
	Returns the m value of the specified node in the simple curve.
const double *	mData () const
	Returns a const pointer to the m vertex data, or `nullptr` if the simple curve does not have m values.
bool	moveVertex (QgsVertexId position, const QgsPoint &newPos) override
	Moves a vertex within the geometry.
QVector< double >	mVector () const
	Returns the m vertex values as a vector.
int	nCoordinates () const override
	Returns the number of nodes contained in the geometry.
int	numPoints () const override
	Returns the number of points in the curve.
QgsPoint	pointN (int i) const
	Returns the specified point from inside the simple curve.
void	points (QgsPointSequence &pts) const override
	Returns a list of points within the curve.
QgsSimpleCurve *	reversed () const override
	Returns a reversed copy of the curve, where the direction of the curve has been flipped.
void	scroll (int firstVertexIndex) final
	Scrolls the curve vertices so that they start with the vertex at the given index.
void	setMAt (int index, double m)
	Sets the m value of the specified node in the simple curve.
void	setPoints (const QgsPointSequence &points)
	Resets the simple curve to match the specified list of points.
void	setXAt (int index, double x)
	Sets the x-coordinate of the specified node in the simple curve.
void	setYAt (int index, double y)
	Sets the y-coordinate of the specified node in the simple curve.
void	setZAt (int index, double z)
	Sets the z-coordinate of the specified node in the simple curve.
QgsPoint	startPoint () const override
	Returns the starting point of the curve.
void	swapXy () override
	Swaps the x and y coordinates from the geometry.
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.
int	wkbSize (QgsAbstractGeometry::WkbFlags flags=QgsAbstractGeometry::WkbFlags()) const override
	Returns the length of the QByteArray returned by asWkb().
double	xAt (int index) const override
	Returns the x-coordinate of the specified node in the line string.
const double *	xData () const
	Returns a const pointer to the x vertex data.
QVector< double >	xVector () const
	Returns the x vertex values as a vector.
double	yAt (int index) const override
	Returns the y-coordinate of the specified node in the line string.
const double *	yData () const
	Returns a const pointer to the y vertex data.
QVector< double >	yVector () const
	Returns the y vertex values as a vector.
double	zAt (int index) const override
	Returns the z-coordinate of the specified node in the simple curve.
const double *	zData () const
	Returns a const pointer to the z vertex data, or `nullptr` if the simple curve does not have z values.
QVector< double >	zVector () const
	Returns the z vertex values as a vector.
Public Member Functions inherited from QgsCurve
	QgsCurve ()=default
void	adjacentVertices (QgsVertexId vertex, QgsVertexId &previousVertex, QgsVertexId &nextVertex) const override
	Returns the vertices adjacent to a specified vertex within a 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.
virtual QPolygonF	asQPolygonF () const
	Returns a QPolygonF representing the points.
QgsAbstractGeometry *	boundary () const override
	Returns the closure of the combinatorial boundary of the geometry (ie the topological boundary of the geometry).
QgsBox3D	boundingBox3D () const override
	Returns the 3D bounding box for the geometry.
QgsCoordinateSequence	coordinateSequence () const override
	Retrieves the sequence of geometries, rings and nodes.
bool	hasVertex (QgsVertexId position) const override
	Returns `true` if the geometry contains a vertex matching the given position.
virtual bool	isClosed () const
	Returns `true` if the curve is closed.
virtual bool	isClosed2D () const
	Returns true if the curve is closed.
virtual bool	isRing () const
	Returns `true` if the curve is a ring.
bool	isValid (QString &error, Qgis::GeometryValidityFlags flags=Qgis::GeometryValidityFlags()) const override
	Checks validity of the geometry, and returns `true` if the geometry is valid.
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).
bool	operator!= (const QgsAbstractGeometry &other) const override
bool	operator== (const QgsAbstractGeometry &other) const override
Qgis::AngularDirection	orientation () const
	Returns the curve's orientation, e.g.
int	partCount () const override
	Returns count of parts contained in the geometry.
int	ringCount (int part=0) const override
	Returns the number of rings of which this geometry is built.
QgsCurve *	segmentize (double tolerance=M_PI_2/90, SegmentationToleranceType toleranceType=MaximumAngle) const override
	Returns a geometry without curves.
double	sinuosity () const
	Returns the curve sinuosity, which is the ratio of the curve length() to curve straightDistance2d().
double	straightDistance2d () const
	Returns the straight distance of the curve, i.e.
QgsCurve *	toCurveType () const override
	Returns the geometry converted to the more generic curve type.
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 QgsAbstractGeometry
	QgsAbstractGeometry ()=default
	QgsAbstractGeometry (const QgsAbstractGeometry &geom)
virtual	~QgsAbstractGeometry ()=default
virtual double	area () const
	Returns the planar, 2-dimensional area of the geometry.
virtual double	area3D () const
	Returns the 3-dimensional surface area of the geometry.
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 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 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.
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 double	perimeter () const
	Returns the planar, 2-dimensional perimeter 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 QgsCircularString *	cast (const QgsAbstractGeometry *geom)
	Cast the geom to a QgsCircularString.
static QgsCircularString *	cast (QgsAbstractGeometry *geom)
	Cast the geom to a QgsCircularString.
static QgsCircularString	fromTwoPointsAndCenter (const QgsPoint &p1, const QgsPoint &p2, const QgsPoint &center, bool useShortestArc=true)
	Creates a circular string with a single arc representing the curve from p1 to p2 with the specified center.
Static Public Member Functions inherited from QgsSimpleCurve
static const QgsSimpleCurve *	cast (const QgsAbstractGeometry *geom)
	Cast the geom to a QgsSimpleCurve.
static QgsSimpleCurve *	cast (QgsAbstractGeometry *geom)
	Cast the geom to a QgsSimpleCurve.
Static Public Member Functions inherited from QgsCurve
static const QgsCurve *	cast (const QgsAbstractGeometry *geom)
	Cast the geom to a QgsCurve.
static QgsCurve *	cast (QgsAbstractGeometry *geom)
	Cast the geom to a QgsCurve.

Protected Member Functions
QgsBox3D	calculateBoundingBox3D () const override
	Calculates the minimal 3D bounding box for the geometry.
Protected Member Functions inherited from QgsSimpleCurve
	QgsSimpleCurve ()=default
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.
void	importVerticesFromWkb (const QgsConstWkbPtr &wkb)
	Imports vertices from wkb geometry representation.
void	splitCurveAtVertexProtected (int index, QVector< double > &x1, QVector< double > &y1, QVector< double > &z1, QVector< double > &m1, QVector< double > &x2, QVector< double > &y2, QVector< double > &z2, QVector< double > &m2) const
	Returns coordinate vectors for the split curves.
Protected Member Functions inherited from QgsCurve
int	childCount () const override
	Returns number of child geometries (for geometries with child geometries) or child points (for geometries without child geometries - i.e.
QgsPoint	childPoint (int index) const override
	Returns point at index (for geometries without child geometries - i.e.
void	clearCache () const override
	Clears any cached parameters associated with the geometry, e.g., bounding boxes.
bool	snapToGridPrivate (double hSpacing, double vSpacing, double dSpacing, double mSpacing, const QVector< double > &srcX, const QVector< double > &srcY, const QVector< double > &srcZ, const QVector< double > &srcM, QVector< double > &outX, QVector< double > &outY, QVector< double > &outZ, QVector< double > &outM, bool removeRedundantPoints) const
	Helper function for QgsCurve subclasses to snap to grids.
Protected Member Functions inherited from QgsAbstractGeometry
virtual QgsRectangle	calculateBoundingBox () const
	Default calculator for the minimal bounding box for the geometry.
virtual QgsAbstractGeometry *	childGeometry (int index) const
	Returns pointer to child geometry (for geometries with 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.

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 Attributes inherited from QgsSimpleCurve
QVector< double >	mM
QVector< double >	mX
QVector< double >	mY
QVector< double >	mZ
Protected Attributes inherited from QgsCurve
QgsBox3D	mBoundingBox
	Cached bounding box.
bool	mHasCachedSummedUpArea = false
bool	mHasCachedSummedUpArea3D = false
double	mSummedUpArea = 0
double	mSummedUpArea3D = 0
Protected Attributes inherited from QgsAbstractGeometry
Qgis::WkbType	mWkbType = Qgis::WkbType::Unknown

Detailed Description

Circular string geometry type.

Definition at line 36 of file qgscircularstring.h.

Constructor & Destructor Documentation

◆ QgsCircularString() [1/3]

QgsCircularString::QgsCircularString ( )

Constructs an empty circular string.

Definition at line 39 of file qgscircularstring.cpp.

◆ QgsCircularString() [2/3]

QgsCircularString::QgsCircularString	(	const QgsPoint &	p1,
		const QgsPoint &	p2,
		const QgsPoint &	p3 )

Constructs a circular string with a single arc passing through p1, p2 and p3.

Since: QGIS 3.2

Definition at line 44 of file qgscircularstring.cpp.

◆ QgsCircularString() [3/3]

QgsCircularString::QgsCircularString	(	const QVector< double > &	x,
		const QVector< double > &	y,
		const QVector< double > &	z = QVector<double>(),
		const QVector< double > &	m = QVector<double>() )

Construct a circular string from arrays of coordinates.

If the z or m arrays are non-empty then the resultant circular string will have z and m types accordingly.

This constructor is more efficient then calling setPoints().

If the sizes of x and y are non-equal then the resultant circular string will be created using the minimum size of these arrays.

Warning: It is the caller's responsibility to ensure that the supplied arrays are of odd sizes.

Since: QGIS 3.20

Definition at line 77 of file qgscircularstring.cpp.

Member Function Documentation

◆ addToPainterPath()

void QgsCircularString::addToPainterPath ( QPainterPath & path ) const

overridevirtual

Adds a curve to a painter path.

Implements QgsCurve.

Definition at line 516 of file qgscircularstring.cpp.

◆ asGml2()

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

overridevirtual

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()

Implements QgsAbstractGeometry.

Definition at line 298 of file qgscircularstring.cpp.

◆ asGml3()

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

overridevirtual

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()

Implements QgsAbstractGeometry.

Definition at line 306 of file qgscircularstring.cpp.

◆ asJsonObject()

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

overridevirtual

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 from QgsAbstractGeometry.

Definition at line 325 of file qgscircularstring.cpp.

◆ calculateBoundingBox3D()

QgsBox3D QgsCircularString::calculateBoundingBox3D ( ) const

overrideprotectedvirtual

Calculates the minimal 3D bounding box for the geometry.

See also: calculateBoundingBox()

Since: QGIS 3.34

Reimplemented from QgsAbstractGeometry.

Definition at line 152 of file qgscircularstring.cpp.

◆ cast() [1/2]

const QgsCircularString * QgsCircularString::cast ( const QgsAbstractGeometry * geom )

inlinestatic

Cast the geom to a QgsCircularString.

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

Objects will be automatically converted to the appropriate target type.

Note: Not available in Python.

Definition at line 136 of file qgscircularstring.h.

◆ cast() [2/2]

QgsCircularString * QgsCircularString::cast ( QgsAbstractGeometry * geom )

inlinestatic

Cast the geom to a QgsCircularString.

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

Objects will be automatically converted to the appropriate target type.

Note: Not available in Python.

Definition at line 151 of file qgscircularstring.h.

◆ clear()

void QgsCircularString::clear ( )

overridevirtual

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

Implements QgsAbstractGeometry.

Definition at line 146 of file qgscircularstring.cpp.

◆ clone()

QgsCircularString * QgsCircularString::clone ( ) const

overridevirtual

Clones the geometry by performing a deep copy.

Implements QgsCurve.

Definition at line 141 of file qgscircularstring.cpp.

◆ closestSegment()

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

overridevirtual

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

Implements QgsAbstractGeometry.

Definition at line 697 of file qgscircularstring.cpp.

◆ createEmptyWithSameType()

QgsCircularString * QgsCircularString::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()

Implements QgsAbstractGeometry.

Definition at line 129 of file qgscircularstring.cpp.

◆ curveSubstring()

QgsCircularString * QgsCircularString::curveSubstring	(	double	startDistance,
		double	endDistance ) const

overridevirtual

Returns a new curve representing a substring of this curve.

The startDistance and endDistance arguments specify the length along the curve which the substring should start and end at. If the endDistance is greater than the total length of the curve then any "extra" length will be ignored.

If z or m values are present, the output z and m will be interpolated using the existing vertices' z or m values.

Since: QGIS 3.4

Implements QgsCurve.

Definition at line 1240 of file qgscircularstring.cpp.

◆ curveToLine()

QgsLineString * QgsCircularString::curveToLine	(	double	tolerance = M_PI_2/90,
		SegmentationToleranceType	toleranceType = MaximumAngle ) const

overridevirtual

Returns a new line string geometry corresponding to a segmentized approximation of the curve.

Parameters

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

Uses a MaximumAngle tolerance of 1 degrees by default (360 segments in a full circle)

Implements QgsCurve.

Definition at line 354 of file qgscircularstring.cpp.

◆ deleteVertex()

bool QgsCircularString::deleteVertex ( QgsVertexId position )

overridevirtual

Deletes a vertex within the geometry.

Parameters

position vertex id for vertex to delete

Returns: true if delete was successful

See also: insertVertex; moveVertex

Implements QgsAbstractGeometry.

Definition at line 577 of file qgscircularstring.cpp.

◆ deleteVertices()

bool QgsCircularString::deleteVertices ( const QSet< QgsVertexId > & positions )

overridevirtual

Deletes vertices within the geometry.

If positions contains vertices not belonging to the geometry, false is returned and the geometry is not modified. If a vertex cannot be deleted, the method returns false and the geometry may be left in a partially modified and invalid state.

Parameters

positions set of vertex ids to delete

Returns: true if all requested vertices were deleted, false if at least one vertex could not be deleted

See also: deleteVertex

Since: QGIS 4.2

Implements QgsAbstractGeometry.

Definition at line 623 of file qgscircularstring.cpp.

◆ distanceBetweenVertices()

double QgsCircularString::distanceBetweenVertices	(	QgsVertexId	fromVertex,
		QgsVertexId	toVertex ) const

overridevirtual

Returns the distance along the curve between two vertices.

This method calculates the accumulated distance along the curve from one vertex to another. For circular strings, this includes following the arc path precisely.

Note: For 3D geometries, the distance calculation includes the Z coordinate component.

Parameters

fromVertex	the starting vertex ID
toVertex	the ending vertex ID

Returns: distance along the curve between the vertices, or -1 if either vertex is invalid

Since: QGIS 4.00

Implements QgsCurve.

Definition at line 1054 of file qgscircularstring.cpp.

◆ draw()

void QgsCircularString::draw ( QPainter & p ) const

overridevirtual

Draws the geometry using the specified QPainter.

Parameters

p	destination QPainter

Implements QgsAbstractGeometry.

Definition at line 497 of file qgscircularstring.cpp.

◆ drawAsPolygon()

void QgsCircularString::drawAsPolygon ( QPainter & p ) const

overridevirtual

Draws the curve as a polygon on the specified QPainter.

Parameters

p	destination QPainter

Implements QgsCurve.

Definition at line 541 of file qgscircularstring.cpp.

◆ fromTwoPointsAndCenter()

QgsCircularString QgsCircularString::fromTwoPointsAndCenter	(	const QgsPoint &	p1,
		const QgsPoint &	p2,
		const QgsPoint &	center,
		bool	useShortestArc = true )

static

Creates a circular string with a single arc representing the curve from p1 to p2 with the specified center.

If useShortestArc is true, then the arc returned will be that corresponding to the shorter arc from p1 to p2. If it is false, the longer arc from p1 to p2 will be used (i.e. winding the other way around the circle).

Since: QGIS 3.2

Definition at line 123 of file qgscircularstring.cpp.

◆ geometryType()

QString QgsCircularString::geometryType ( ) const

overridevirtual

Returns a unique string representing the geometry type.

See also: wkbType; wktTypeStr

Implements QgsAbstractGeometry.

Definition at line 136 of file qgscircularstring.cpp.

◆ hasCurvedSegments()

bool QgsCircularString::hasCurvedSegments ( ) const

overridevirtual

Returns true if the geometry contains curved segments.

Reimplemented from QgsAbstractGeometry.

Definition at line 899 of file qgscircularstring.cpp.

◆ indexOf()

int QgsCircularString::indexOf ( const QgsPoint & point ) const

finalvirtual

Returns the index of the first vertex matching the given point, or -1 if a matching vertex is not found.

Note: If the curve has m or z values then the search point must have exactly matching m and z values in order to be matched against the curve's vertices.; This method only matches against segment vertices, not curve vertices.

Since: QGIS 3.20

Implements QgsCurve.

Definition at line 439 of file qgscircularstring.cpp.

◆ insertVertex()

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

overridevirtual

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

Implements QgsAbstractGeometry.

Definition at line 546 of file qgscircularstring.cpp.

◆ interpolatePoint()

QgsPoint * QgsCircularString::interpolatePoint ( double distance ) const

overridevirtual

Returns an interpolated point on the curve at the specified distance.

If z or m values are present, the output z and m will be interpolated using the existing vertices' z or m values.

If distance is negative, or is greater than the length of the curve, nullptr will be returned.

Since: QGIS 3.4

Implements QgsCurve.

Definition at line 1173 of file qgscircularstring.cpp.

◆ isValid()

bool QgsCircularString::isValid	(	QString &	error,
		Qgis::GeometryValidityFlags	flags = Qgis::GeometryValidityFlags() ) const

overridevirtual

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

Implements QgsAbstractGeometry.

Definition at line 332 of file qgscircularstring.cpp.

◆ length()

double QgsCircularString::length ( ) const

overridevirtual

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 from QgsAbstractGeometry.

Definition at line 343 of file qgscircularstring.cpp.

◆ pointAt()

bool QgsCircularString::pointAt	(	int	node,
		QgsPoint &	point,
		Qgis::VertexType &	type ) const

overridevirtual

Returns the point and vertex type of a point within the curve.

Parameters

node	node number, where the first node is 0
point	will be set to point at corresponding node in the curve
type	will be set to the vertex type of the node

Returns: true if node exists within the curve

Implements QgsCurve.

Definition at line 736 of file qgscircularstring.cpp.

◆ removeDuplicateNodes()

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

overridevirtual

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.

Implements QgsAbstractGeometry.

Definition at line 388 of file qgscircularstring.cpp.

◆ reversed()

QgsCircularString * QgsCircularString::reversed ( ) const

overridevirtual

Returns a reversed copy of the curve, where the direction of the curve has been flipped.

Implements QgsCurve.

Definition at line 1168 of file qgscircularstring.cpp.

◆ segmentLength()

double QgsCircularString::segmentLength ( QgsVertexId startVertex ) const

overridevirtual

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.

Implements QgsAbstractGeometry.

Definition at line 1037 of file qgscircularstring.cpp.

◆ simplifyByDistance()

QgsAbstractGeometry * QgsCircularString::simplifyByDistance ( double tolerance ) const

overridevirtual

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

Implements QgsAbstractGeometry.

Definition at line 382 of file qgscircularstring.cpp.

◆ snappedToGrid()

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

overridevirtual

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)

Implements QgsAbstractGeometry.

Definition at line 369 of file qgscircularstring.cpp.

◆ splitCurveAtVertex()

std::tuple< std::unique_ptr< QgsCurve >, std::unique_ptr< QgsCurve > > QgsCircularString::splitCurveAtVertex ( int index ) const

finalvirtual

Splits the curve at the specified vertex index, returning two curves which represent the portion of the curve up to including the vertex at index, and the portion of the curve from the vertex at index (inclusive) to the end of the curve.

Note: The vertex index must correspond to a segment vertex, not a curve vertex.; Not available in Python bindings.

Since: QGIS 3.20

Implements QgsCurve.

Definition at line 476 of file qgscircularstring.cpp.

◆ sumUpArea()

void QgsCircularString::sumUpArea ( double & sum ) const

overridevirtual

Sums up the area of the curve by iterating over the vertices (shoelace formula).

Implements QgsCurve.

Definition at line 747 of file qgscircularstring.cpp.

◆ sumUpArea3D()

void QgsCircularString::sumUpArea3D ( double & sum ) const

overridevirtual

Sums up the 3d area of the curve by iterating over the vertices (shoelace formula).

Since: QGIS 4.0

Implements QgsCurve.

Definition at line 817 of file qgscircularstring.cpp.

◆ vertexAngle()

double QgsCircularString::vertexAngle ( QgsVertexId vertex ) const

overridevirtual

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

Implements QgsAbstractGeometry.

Definition at line 983 of file qgscircularstring.cpp.

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

/build/qgis-4.1.0+git20260622+3fcefe620d1+99sid/src/core/geometry/qgscircularstring.h
/build/qgis-4.1.0+git20260622+3fcefe620d1+99sid/src/core/geometry/qgscircularstring.cpp

Public Member Functions

Static Public Member Functions

Protected Member Functions

Additional Inherited Members

Detailed Description

Constructor & Destructor Documentation

◆ QgsCircularString() [1/3]

◆ QgsCircularString() [2/3]

◆ QgsCircularString() [3/3]

Member Function Documentation

◆ addToPainterPath()

◆ asGml2()

◆ asGml3()

◆ asJsonObject()

◆ calculateBoundingBox3D()

◆ cast() [1/2]

◆ cast() [2/2]

◆ clear()

◆ clone()

◆ closestSegment()

◆ createEmptyWithSameType()

◆ curveSubstring()

◆ curveToLine()

◆ deleteVertex()

◆ deleteVertices()

◆ distanceBetweenVertices()

◆ draw()

◆ drawAsPolygon()

◆ fromTwoPointsAndCenter()

◆ geometryType()

◆ hasCurvedSegments()

◆ indexOf()

◆ insertVertex()

◆ interpolatePoint()

◆ isValid()

◆ length()

◆ pointAt()

◆ removeDuplicateNodes()

◆ reversed()

◆ segmentLength()

◆ simplifyByDistance()

◆ snappedToGrid()

◆ splitCurveAtVertex()

◆ sumUpArea()

◆ sumUpArea3D()

◆ vertexAngle()