Class: QgsCompoundCurve

class qgis.core.QgsCompoundCurve

Bases: QgsCurve

Compound curve geometry type

New in version 2.10:

Methods

addCurve	Adds a curve to the geometry (takes ownership).
addMValue	param mValue:
addToPainterPath	param path:
addVertex	Adds a vertex to the end of the geometry.
addZValue	param zValue:
asGml2	param doc:
asGml3	param doc:
asWkb	param flags:
asWkt	param precision:
boundingBoxIntersects	param box3d:
calculateBoundingBox	Default calculator for the minimal bounding box for the geometry.
calculateBoundingBox3D	rtype: QgsBox3D
childCount	Returns number of child geometries (for geometries with child geometries) or child points (for geometries without child geometries - i.e. curve / point).
childGeometry	Returns pointer to child geometry (for geometries with child geometries - i.e. geom.
childPoint	Returns point at index (for geometries without child geometries - i.e. curve / point).
clear
clearCache	Clears any cached parameters associated with the geometry, e.g., bounding boxes
clone	rtype: QgsCompoundCurve
close	Appends first point if not already closed.
closestSegment	param pt:
compareToSameClass	param other:
condenseCurves	Condenses the curves in this geometry by combining adjacent linestrings a to a single continuous linestring, and combining adjacent circularstrings to a single continuous circularstring.
createEmptyWithSameType	rtype: QgsCompoundCurve
curveAt	Returns the curve at the specified index.
curveSubstring	param startDistance:
curveToLine	Returns a new line string geometry corresponding to a segmentized approximation of the curve.
deleteVertex	param position:
dimension	rtype: int
draw	param p:
drawAsPolygon	param p:
dropMValue	rtype: bool
dropZValue	rtype: bool
endPoint	rtype: QgsPoint
equals	param other:
fromWkb	param wkb:
fromWkt	param wkt:
geometryType	rtype: str
hasChildGeometries	Returns whether the geometry has any child geometries (False for point / curve, True otherwise)
hasCurvedSegments	rtype: bool
indexOf	param point:
insertVertex	param position:
interpolatePoint	param distance:
isEmpty	rtype: bool
isValid	param flags:
length	rtype: float
mAt	param index:
moveVertex	param position:
nCurves	Returns the number of curves in the geometry.
numPoints	rtype: int
pointAt	param node:
points	rtype: List[QgsPoint]
removeCurve	Removes a curve from the geometry.
removeDuplicateNodes	param epsilon:
reversed	rtype: QgsCompoundCurve
scroll	param firstVertexIndex:
segmentLength	param startVertex:
setZMTypeFromSubGeometry	Updates the geometry type based on whether sub geometries contain z or m values.
simplifiedTypeRef	rtype: QgsAbstractGeometry
snappedToGrid	param hSpacing:
sortIndex	Returns the sort index for the geometry, used in the compareTo() method to compare geometries of different types.
startPoint	rtype: QgsPoint
sumUpArea	rtype: float
swapXy
toggleCircularAtVertex	Converts the vertex at the given position from/to circular
transform	param ct:
vertexAngle	param vertex:
wkbSize	param flags:
xAt	param index:
yAt	param index:
zAt	param index:

addCurve(self, c: QgsCurve, extendPrevious: bool = False)

Adds a curve to the geometry (takes ownership).

Since QGIS 3.20, if extendPrevious is True, then adding a LineString when the last existing curve in the compound curve is also a LineString will cause the existing linestring to be extended with the newly added LineString vertices instead of appending a whole new LineString curve to the compound curve. This can result in simplified compound curves with lesser number of component curves while still being topologically identical to the desired result.

Parameters:

• c (QgsCurve) –

• extendPrevious (bool = False) –

addMValue(self, mValue: float = 0) → bool

Parameters:

mValue (float = 0) –

Return type:

bool

addToPainterPath(self, path: QPainterPath)

Parameters:

path (QPainterPath) –

addVertex(self, pt: QgsPoint)

Adds a vertex to the end of the geometry.

Parameters:

pt (QgsPoint) –

addZValue(self, zValue: float = 0) → bool

Parameters:

zValue (float = 0) –

Return type:

bool

asGml2(self, doc: QDomDocument, precision: int = 17, ns: str = '', axisOrder: QgsAbstractGeometry.AxisOrder = QgsAbstractGeometry.AxisOrder.XY) → QDomElement

Parameters:

• doc (QDomDocument) –

• precision (int = 17) –

• ns (str = '') –

• axisOrder (QgsAbstractGeometry.AxisOrder = QgsAbstractGeometry.AxisOrder.XY) –

Return type:

QDomElement

asGml3(self, doc: QDomDocument, precision: int = 17, ns: str = '', axisOrder: QgsAbstractGeometry.AxisOrder = QgsAbstractGeometry.AxisOrder.XY) → QDomElement

Parameters:

• doc (QDomDocument) –

• precision (int = 17) –

• ns (str = '') –

• axisOrder (QgsAbstractGeometry.AxisOrder = QgsAbstractGeometry.AxisOrder.XY) –

Return type:

QDomElement

asWkb(self, flags: QgsAbstractGeometry.WkbFlags | QgsAbstractGeometry.WkbFlag = QgsAbstractGeometry.WkbFlags()) → QByteArray

Parameters:

flags (Union[QgsAbstractGeometry.WkbFlags) –

Return type:

QByteArray

asWkt(self, precision: int = 17) → str

Parameters:

precision (int = 17) –

Return type:

str

boundingBoxIntersects(self, box3d: QgsBox3D) → bool

Parameters:

box3d (QgsBox3D) –

Return type:

bool

calculateBoundingBox(self) → QgsRectangle

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.

calculateBoundingBox3D(self) → QgsBox3D

Return type:

QgsBox3D

childCount(self) → int

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

New in version 3.0.

childGeometry(self, index: int) → QgsAbstractGeometry

Returns pointer to child geometry (for geometries with child geometries - i.e. geom. collection / polygon)

Note

used for vertex_iterator implementation

New in version 3.0.

childPoint(self, index: int) → QgsPoint

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

Note

used for vertex_iterator implementation

New in version 3.0.

clear(self)

clearCache(self)

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

clone(self) → QgsCompoundCurve

Return type:

QgsCompoundCurve

close(self)

Appends first point if not already closed.

closestSegment(self, pt: QgsPoint, epsilon: float = 4 * DBL_EPSILON) → Tuple[float, QgsPoint, QgsVertexId, int]

Parameters:

• pt (QgsPoint) –

• epsilon (float = 4*DBL_EPSILON) –

Return type:

Tuple[float, QgsPoint, QgsVertexId, int]

compareToSameClass(self, other: QgsAbstractGeometry) → int

Parameters:

other (QgsAbstractGeometry) –

Return type:

int

condenseCurves(self)

Condenses the curves in this geometry by combining adjacent linestrings a to a single continuous linestring, and combining adjacent circularstrings to a single continuous circularstring.

New in version 3.20.

createEmptyWithSameType(self) → QgsCompoundCurve

Return type:

QgsCompoundCurve

curveAt(self, i: int) → QgsCurve

Returns the curve at the specified index.

Parameters:

i (int) –

Return type:

QgsCurve

curveSubstring(self, startDistance: float, endDistance: float) → QgsCompoundCurve

Parameters:

• startDistance (float) –

• endDistance (float) –

Return type:

QgsCompoundCurve

curveToLine(self, tolerance: float = M_PI_2 / 90, toleranceType: QgsAbstractGeometry.SegmentationToleranceType = QgsAbstractGeometry.MaximumAngle) → QgsLineString

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

Parameters:

• tolerance (float = M_PI_2/90) – segmentation tolerance

• toleranceType (QgsAbstractGeometry.SegmentationToleranceType = QgsAbstractGeometry.MaximumAngle) – maximum segmentation angle or maximum difference between approximation and curve

Return type:

QgsLineString

deleteVertex(self, position: QgsVertexId) → bool

Parameters:

position (QgsVertexId) –

Return type:

bool

dimension(self) → int

Return type:

int

draw(self, p: QPainter)

Parameters:

p (QPainter) –

drawAsPolygon(self, p: QPainter)

Parameters:

p (QPainter) –

dropMValue(self) → bool

Return type:

bool

dropZValue(self) → bool

Return type:

bool

endPoint(self) → QgsPoint

Return type:

QgsPoint

equals(self, other: QgsCurve) → bool

Parameters:

other (QgsCurve) –

Return type:

bool

fromWkb(self, wkb: QgsConstWkbPtr) → bool

Parameters:

wkb (QgsConstWkbPtr) –

Return type:

bool

fromWkt(self, wkt: str) → bool

Parameters:

wkt (str) –

Return type:

bool

geometryType(self) → str

Return type:

str

hasChildGeometries(self) → bool

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

Note

used for vertex_iterator implementation

New in version 3.0.

hasCurvedSegments(self) → bool

Return type:

bool

indexOf(self, point: QgsPoint) → int

Parameters:

point (QgsPoint) –

Return type:

int

insertVertex(self, position: QgsVertexId, vertex: QgsPoint) → bool

Parameters:

• position (QgsVertexId) –

• vertex (QgsPoint) –

Return type:

bool

interpolatePoint(self, distance: float) → QgsPoint

Parameters:

distance (float) –

Return type:

QgsPoint

isEmpty(self) → bool

Return type:

bool

isValid(self, flags: Qgis.GeometryValidityFlags | Qgis.GeometryValidityFlag = Qgis.GeometryValidityFlags()) → Tuple[bool, str]

Parameters:

flags (Union[Qgis.GeometryValidityFlags) –

Return type:

Tuple[bool, str]

length(self) → float

Return type:

float

mAt(self, index: int) → float

Parameters:

index (int) –

Return type:

float

moveVertex(self, position: QgsVertexId, newPos: QgsPoint) → bool

Parameters:

• position (QgsVertexId) –

• newPos (QgsPoint) –

Return type:

bool

nCurves(self) → int

Returns the number of curves in the geometry.

Return type:

int

numPoints(self) → int

Return type:

int

pointAt(self, node: int, point: QgsPoint) → Tuple[bool, Qgis.VertexType]

Parameters:

• node (int) –

• point (QgsPoint) –

Return type:

Tuple[bool, Qgis.VertexType]

points(self) → List[QgsPoint]

Return type:

List[QgsPoint]

removeCurve(self, i: int)

Removes a curve from the geometry.

Parameters:

i (int) – index of curve to remove

removeDuplicateNodes(self, epsilon: float = 4 * DBL_EPSILON, useZValues: bool = False) → bool

Parameters:

• epsilon (float = 4*DBL_EPSILON) –

• useZValues (bool = False) –

Return type:

bool

reversed(self) → QgsCompoundCurve

Return type:

QgsCompoundCurve

scroll(self, firstVertexIndex: int)

Parameters:

firstVertexIndex (int) –

segmentLength(self, startVertex: QgsVertexId) → float

Parameters:

startVertex (QgsVertexId) –

Return type:

float

setZMTypeFromSubGeometry(self, subggeom: QgsAbstractGeometry, baseGeomType: Qgis.WkbType)

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

simplifiedTypeRef(self) → QgsAbstractGeometry

Return type:

QgsAbstractGeometry

snappedToGrid(self, hSpacing: float, vSpacing: float, dSpacing: float = 0, mSpacing: float = 0) → QgsCompoundCurve

Parameters:

• hSpacing (float) –

• vSpacing (float) –

• dSpacing (float = 0) –

• mSpacing (float = 0) –

Return type:

QgsCompoundCurve

sortIndex(self) → int

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

New in version 3.20.

startPoint(self) → QgsPoint

Return type:

QgsPoint

sumUpArea(self) → float

Return type:

float

swapXy(self)

toggleCircularAtVertex(self, position: QgsVertexId) → bool

Converts the vertex at the given position from/to circular

Return type:

bool

Returns:

False if atVertex does not correspond to a valid vertex on this geometry (including if this geometry is a Point), or if the specified vertex can’t be converted (e.g. start/end points).

New in version 3.20.

Parameters:

position (QgsVertexId) –

transform(self, ct: QgsCoordinateTransform, d: Qgis.TransformDirection = Qgis.TransformDirection.Forward, transformZ: bool = False)

transform(self, t: QTransform, zTranslate: float = 0, zScale: float = 1, mTranslate: float = 0, mScale: float = 1) → None

transform(self, transformer: QgsAbstractGeometryTransformer, feedback: QgsFeedback = None) → bool

Parameters:

• ct (QgsCoordinateTransform) –

• d (Qgis.TransformDirection = Qgis.TransformDirection.Forward) –

• transformZ (bool = False) –

vertexAngle(self, vertex: QgsVertexId) → float

Parameters:

vertex (QgsVertexId) –

Return type:

float

wkbSize(self, flags: QgsAbstractGeometry.WkbFlags | QgsAbstractGeometry.WkbFlag = QgsAbstractGeometry.WkbFlags()) → int

Parameters:

flags (Union[QgsAbstractGeometry.WkbFlags) –

Return type:

int

xAt(self, index: int) → float

Parameters:

index (int) –

Return type:

float

yAt(self, index: int) → float

Parameters:

index (int) –

Return type:

float

zAt(self, index: int) → float

Parameters:

index (int) –

Return type:

float