Loop Class

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

see Curve Collections learning article.



Name Description
constructor(): Loop Test if other is an instance of 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): AnyCurve 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 variable length list of CurvePrimitives  
createArray(curves: CurvePrimitive[]): Loop Static Create a loop from an array of curve primitives  
createPolygon(points: IndexedXYZCollection | Point3d[]): Loop Static Create a loop from an array of points  

Inherited methods

Name Inherited from Description
checkForNonLinearPrimitives(): boolean CurveChain return true if the curve collection has any primitives other than LineSegment3d and LineString3d
childIndex(target: undefined | CurvePrimitive, alsoSearchProxies?: boolean): undefined | number CurveChain Return the index where target is found in the array of children
clone(): CurveCollection CurveChain Return a deep copy.
cloneTransformed(transform: Transform): undefined | CurveCollection CurveChain Create a deep copy of transformed curves.
cloneWithExpandedLineStrings(): CurveCollection CurveChain Create a deep copy with all linestrings expanded to multiple LineSegment3d.
closestPoint(spacePoint: Point3d): undefined | CurveLocationDetail CurveChain Return the closest point on the contained curves
collectCurvePrimitives(collectorArray?: CurvePrimitive[], smallestPossiblePrimitives: boolean = false, explodeLineStrings: boolean = false): CurvePrimitive[] CurveChain Return an array containing only the curve primitives.
cyclicCurvePrimitive(index: number, cyclic: boolean = true): undefined | CurvePrimitive CurveChain Return the [index] curve primitive, optionally using modulo to mapindex to the cyclic indexing.
extendRange(range: Range3d, transform?: Transform): void CurveChain invoke curve.extendRange(range, transform) for each child
getChild(i: number): undefined | CurvePrimitive CurveChain Return a child by index
getPackedStrokes(options?: StrokeOptions): undefined | GrowableXYZArray CurveChain Stroke the chain into a simple xyz array.
isAlmostEqual(other: GeometryQuery): boolean CurveChain test for exact structure and nearly identical geometry.
maxGap(): number 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 CurveChain Evaluate an indexed curve at a fraction.
projectedParameterRange(ray: Vector3d | Ray3d, lowHigh?: Range1d): undefined | Range1d CurveChain Project instance geometry (via dispatch) onto the given ray, and return the extreme fractional parameters of projection.
range(transform?: Transform, result?: Range3d): Range3d CurveChain return the range of the entire (tree) GeometryQuery
reverseChildrenInPlace(): void CurveChain Reverse each child curve (in place)
sumLengths(): number CurveChain Return the sum of the lengths of all contained curves.
tryAddChild(child: undefined | AnyCurve): boolean CurveChain add a child curve.
tryTransformInPlace(transform: Transform): boolean CurveChain Apply transform recursively to children
tryTranslateInPlace(dx: number, dy: number = 0.0, dz: number = 0.0): boolean CurveChain try to move the geometry by dx,dy,dz
areAlmostEqual(a: undefined | GeometryQuery, b: undefined | GeometryQuery): boolean Static CurveChain apply instance method isAlmostEqual if both are defined.
createCurveLocationDetailOnAnyCurvePrimitive(source: undefined | GeometryQuery, fraction: number = 0.5): undefined | CurveLocationDetail Static CurveChain * Find any curve primitive in the source.


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 CurvePrimitive[] CurveChain The curve primitives in the chain.
children Accessor ReadOnly CurvePrimitive[] CurveChain Return the array of CurvePrimitive
geometryCategory Readonly "curveCollection" CurveChain String name for schema properties
isAnyRegionType Accessor ReadOnly boolean CurveChain Return true for planar region types:
* Loop
* ParityRegion
* UnionRegion
isClosedPath Accessor 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 ReadOnly boolean CurveChain Return true for a Path, i.e. a chain of curves joined head-to-tail

Defined in

Last Updated: 22 March, 2023