Loop Class

A Loop is a curve chain that is the boundary of a closed (planar) loop.

@see Curve Collections learning article.

Extends

• CurveChain

Methods

Name	Description
constructor(): Loop
announceToCurveProcessor(processor: RecursiveCurveProcessor, indexInParent: number = -1): void	Invoke processor.announceLoop(this, indexInParent)
cloneEmptyPeer(): Loop	Create a new Loop with no children
cloneStroked(options?: StrokeOptions): Loop	Create a loop with the stroked form of this loop.
dgnBoundaryType(): number	Return the boundary type (2) of a corresponding MicroStation CurveVector
dispatchToGeometryHandler(handler: GeometryHandler): any	Second step of double dispatch: call handler.handleLoop(this)
isSameGeometryClass(other: GeometryQuery): boolean	Test if other is a Loop
create(...curves: CurvePrimitive[]): Loop Static	Create a loop from a variable length list of CurvePrimitives.
createArray(curves: CurvePrimitive[]): Loop Static	Create a loop from an array of CurvePrimitives.
createPolygon(points: IndexedXYZCollection | Point3d[]): Loop Static	Create a loop from an array of coplanar points.

Inherited methods

Name	Inherited from	Description
allTangents(spacePoint: Point3d, options?: TangentOptions): undefined | CurveLocationDetail[] Inherited	CurveChain	Return all points P on the contained curves such that the line containing spacePoint and P is tangent to the
checkForNonLinearPrimitives(): boolean Inherited	CurveChain	Return true if the curve collection has any primitives other than LineSegment3d and LineString3d
childIndex(target: CurvePrimitive, alsoSearchProxies?: boolean): undefined | number Inherited	CurveChain	Return the index where target is found in the array of children.
clone(): CurveCollection Inherited	CurveChain	Return a deep copy.
cloneTransformed(transform: Transform): undefined | CurveCollection Inherited	CurveChain	Create a deep copy of transformed curves.
cloneWithExpandedLineStrings(): CurveCollection Inherited	CurveChain	Create a deep copy with all linestrings broken down into multiple LineSegment3d.
closestPoint(spacePoint: Point3d, _extend: VariantCurveExtendParameter = false, result?: CurveLocationDetail): undefined | CurveLocationDetail Inherited	CurveChain	Return the closest point on the contained curves.
closestTangent(spacePoint: Point3d, options?: TangentOptions): undefined | CurveLocationDetail Inherited	CurveChain	Return the point P on the contained curves such that the line containing spacePoint and P is tangent to the
collectCurvePrimitives(collectorArray?: CurvePrimitive[], smallestPossiblePrimitives: boolean = false, explodeLineStrings: boolean = false): CurvePrimitive[] Inherited	CurveChain	Return an array containing all CurvePrimitives in the instance.
cyclicCurvePrimitive(index: number, cyclic: boolean = true): undefined | CurvePrimitive Inherited	CurveChain	Return the curve primitive at the given index, optionally using modulo to map index to the cyclic indexing.
emitTangents(spacePoint: Point3d, announceTangent: (tangent: CurveLocationDetail) => any, options?: TangentOptions): void Inherited	CurveChain	Announce all points P on the contained curves such that the line containing spacePoint and P is tangent to
endPoint(result?: Point3d): undefined | Point3d Inherited	CurveChain	Return the end point of the curve chain (end point of the last child).
endPointAndDerivative(result?: Ray3d): undefined | Ray3d Inherited	CurveChain	Return the end point and derivative of the last child of the curve chain.
extendRange(range: Range3d, transform?: Transform): void Inherited	CurveChain	Invoke curve.extendRange(range, transform) for each child
findParentOfDescendant(descendant: AnyCurve): undefined | CurveCollection Inherited	CurveChain	Return the immediate parent of the input curve in the instance, or undefined if it is not a descendant.
getChild(i: number): undefined | CurvePrimitive Inherited	CurveChain	Return a child by index
getPackedStrokes(options?: StrokeOptions): undefined | GrowableXYZArray Inherited	CurveChain	Stroke the chain into a simple xyz array.
isAlmostEqual(other: GeometryQuery): boolean Inherited	CurveChain	Test for exact structure and nearly identical geometry.
isAnyRegion(): this is AnyRegion Inherited	CurveChain	Type guard for AnyRegion
isLoop(): this is Loop Inherited	CurveChain	Type guard for Loop
isPath(): this is Path Inherited	CurveChain	Type guard for Path
isPhysicallyClosedCurve(tolerance: number = Geometry.smallMetricDistance, xyOnly: boolean = false): boolean Inherited	CurveChain	Whether the chain start and end points are defined and within tolerance.
maxGap(): number Inherited	CurveChain	Return the max gap between adjacent primitives in Path and Loop collections.
primitiveIndexAndFractionToCurveLocationDetailPointAndDerivative(index: number, fraction: number, cyclic: boolean = false, result?: CurveLocationDetail): undefined | CurveLocationDetail Inherited	CurveChain	Evaluate an indexed curve at a fraction.
projectedParameterRange(ray: Vector3d | Ray3d, lowHigh?: Range1d): undefined | Range1d Inherited	CurveChain	Project instance geometry (via dispatch) onto the given ray, and return the extreme fractional parameters
range(transform?: Transform, result?: Range3d): Range3d Inherited	CurveChain	Return the range of the entire GeometryQuery tree.
reverseChildrenInPlace(): void Inherited	CurveChain	Reverse each child curve (in place).
reverseInPlace(): void Inherited	CurveChain	Same as reverseChildrenInPlace.
startPoint(result?: Point3d): undefined | Point3d Inherited	CurveChain	Return the start point of the curve chain (start point of the first child).
startPointAndDerivative(result?: Ray3d): undefined | Ray3d Inherited	CurveChain	Return the start point and derivative of the first child of the curve chain.
sumLengths(): number Inherited	CurveChain	Return the sum of the lengths of all contained curves.
tryAddChild(child: AnyCurve): boolean Inherited	CurveChain	Add a child curve.
tryTransformInPlace(transform: Transform): boolean Inherited	CurveChain	Apply transform recursively to children
tryTranslateInPlace(dx: number, dy: number = 0.0, dz: number = 0.0): boolean Inherited	CurveChain	Try to move the geometry by dx,dy,dz.
areAlmostEqual(a: GeometryQuery, b: GeometryQuery): boolean Static Inherited	CurveChain	Apply instance method isAlmostEqual if both are defined.
createCurveLocationDetailOnAnyCurvePrimitive(source: GeometryQuery, fraction: number = 0.5): undefined | CurveLocationDetail Static Inherited	CurveChain	Find any CurvePrimitive in the source and evaluate it at the given fraction.

Properties

Name	Type	Description
curveCollectionType Readonly	"loop"	String name for schema properties
isInner	boolean	Tag value that can be set to true for user code to mark inner and outer loops.

Inherited properties

Name	Type	Inherited from	Description
_curves Protected Inherited	CurvePrimitive[]	CurveChain	The curve primitives in the chain.
children Accessor Inherited ReadOnly	CurvePrimitive[]	CurveChain	Return the array of CurvePrimitive
geometryCategory Readonly Inherited	"curveCollection"	CurveChain	String name for schema properties
isAnyRegionType Accessor Inherited ReadOnly	boolean	CurveChain	Return true for planar region types: * Loop * ParityRegion * UnionRegion
isClosedPath Accessor Inherited ReadOnly	boolean	CurveChain	Return true for a single-loop planar region type, i.e. Loop. * This is NOT a test for physical closure of a Path.
isOpenPath Accessor Inherited ReadOnly	boolean	CurveChain	Return true for a Path, i.e. a chain of curves joined head-to-tail

Defined in

• curve/Loop.ts Line 25