API Reference › core-geometry› Bspline › BezierCurveBase

BezierCurveBase Class

Base class for CurvePrimitive (necessarily 3D) with _polygon.

  • This has a Bezier1dNd polygon as a member, and implements dimension-independent methods
  • This exists to support
    • BezierCurve3d -- 3 coordinates x,y,z per block in the Bezier1dNd poles
    • BezierCurve3dH -- 4 coordinates x,y,z,w per block in the Bezier1dNd poles
  • The implementations of "pure 3d" queries is based on calling getPolePoint3d.
  • This has the subtle failure difference that getPolePoint3d call with a valid index on on a 3d curve always succeeds, but on 3dH curve fails when weight is zero.

Extends

Extended by

Methods

Name Description
constructor(blockSize: number, data: Float64Array): BezierCurveBase Protected    
allocateAndZeroBezierWorkData(primaryBezierOrder: number, orderA: number, orderB: number): void Protected set up the _workBezier members with specific order.  
clone(): BezierCurveBase Abstract Return a deep clone.  
clonePartialCurve(fractionA: number, fractionB: number): BezierCurveBase Return a curve primitive which is a portion of this curve.  
cloneTransformed(transform: Transform): BezierCurveBase Return a transformed deep clone.  
computeStrokeCountForOptions(options?: StrokeOptions): number Assess length and turn to determine a stroke count.  
constructOffsetXY(offsetDistanceOrOptions: number | OffsetOptions): undefined | CurvePrimitive | CurvePrimitive[] Construct an offset of the instance curve as viewed in the xy-plane (ignoring z).  
copyPolesAsJsonArray(): any[] Return a simple array of arrays with the control points as [[x,y,z],[x,y,z],..]  
emitStrokableParts(handler: IStrokeHandler, _options?: StrokeOptions): void announce intervals with stroke counts  
emitStrokes(dest: LineString3d, options?: StrokeOptions): void append stroke points to a linestring, based on strokeCount and fractionToPoint from derived class  
endPoint(result?: Point3d): Point3d Return the end point.  
extendRange(rangeToExtend: Range3d, transform?: Transform): void Abstract Concrete classes must implement extendRange .  
fractionToParentFraction(fraction: number): number map fraction from this Bezier curves inherent 0..1 range to the (a,b) range of parent  
getPolePoint3d(i: number, point?: Point3d): undefined | Point3d Abstract Get pole i as a Point3d.  
getPolePoint4d(i: number, point?: Point4d): undefined | Point4d Abstract Get pole i as a Point4d.  
isInPlane(plane: Plane3dByOriginAndUnitNormal): boolean return true if all poles are on a plane.  
polygonLength(): number Return the length of the control polygon.  
projectedParameterRange(ray: Vector3d | Ray3d, lowHigh?: Range1d): undefined | Range1d Project instance geometry (via dispatch) onto the given ray, and return the extreme fractional parameters of projection.  
quickLength(): number Return the control polygon length as a quick length estimate.  
reverseInPlace(): void reverse the poles in place  
saturateInPlace(knotVector: KnotVector, spanIndex: number): boolean saturate the pole in place, using knot intervals from spanIndex of the knotVector  
setInterval(a: number, b: number): void Set mapping to parent curve (e.g.  
startPoint(result?: Point3d): Point3d Return the start point.  

Inherited methods

Name Inherited from Description
addMappedStrokesToLineString3D(map: StrokeCountMap, linestring: LineString3d): number Inherited CurvePrimitive Evaluate strokes at fractions indicated in a StrokeCountMap.
allTangents(spacePoint: Point3d, options?: TangentOptions): undefined | CurveLocationDetail[] Inherited CurvePrimitive Return all points P on the curve such that the line containing spacePoint and P is tangent to the curve in
announceClipIntervals(_clipper: Clipper, _announce?: AnnounceNumberNumberCurvePrimitive): boolean Inherited CurvePrimitive Find intervals of this curvePrimitive that are interior to a clipper
appendPlaneIntersectionPoints(plane: PlaneAltitudeEvaluator, result: CurveLocationDetail[]): number Inherited CurvePrimitive Compute intersections of the curve with a plane.
closestPoint(spacePoint: Point3d, extend?: VariantCurveExtendParameter, result?: CurveLocationDetail): undefined | CurveLocationDetail Inherited CurvePrimitive Search for a point on the curve that is closest to the spacePoint.
closestTangent(spacePoint: Point3d, options?: TangentOptions): undefined | CurveLocationDetail Inherited CurvePrimitive Return the point P on the curve such that the line containing spacePoint and P is tangent to the curve in
collectCurvePrimitives(collectorArray?: CurvePrimitive[], smallestPossiblePrimitives: boolean = false, explodeLinestrings: boolean = false): CurvePrimitive[] Inherited CurvePrimitive Return an array containing only the curve primitives.
collectCurvePrimitivesGo(collectorArray: CurvePrimitive[], _smallestPossiblePrimitives: boolean, _explodeLinestrings: boolean = false): void Inherited CurvePrimitive Return an array containing only the curve primitives.
computeAndAttachRecursiveStrokeCounts(options?: StrokeOptions, parentMap?: StrokeCountMap): void Inherited CurvePrimitive Attach StrokeCountMap structure to this primitive (and recursively to any children)
curveLength(): number Inherited CurvePrimitive Return the length of the curve.
curveLengthBetweenFractions(fraction0: number, fraction1: number): number Inherited CurvePrimitive Returns a (high accuracy) length of the curve between fractional positions.
curveLengthWithFixedIntervalCountQuadrature(fraction0: number, fraction1: number, numInterval: number, numGauss: number = 5): number Inherited CurvePrimitive Run an integration (with a default Gaussian quadrature) with a fixed fractional step
dispatchToGeometryHandler(handler: GeometryHandler): any Abstract Inherited CurvePrimitive Double Dispatch call pattern.
emitTangents(spacePoint: Point3d, announceTangent: (tangent: CurveLocationDetail) => any, options?: TangentOptions): void Inherited CurvePrimitive Announce all points P on the curve such that the line containing spacePoint and P is tangent to the curve in
fractionAndDistanceToPointOnTangent(fraction: number, distance: number): Point3d Inherited CurvePrimitive Construct a point extrapolated along tangent at fraction.
fractionToCurvature(fraction: number): undefined | number Inherited CurvePrimitive Returns the (absolute) curvature magnitude.
fractionToFrenetFrame(fraction: number, result?: Transform): undefined | Transform Inherited CurvePrimitive Construct a frenet frame:
fractionToPoint(fraction: number, result?: Point3d): Point3d Abstract Inherited CurvePrimitive Return the point (x,y,z) on the curve at fractional position.
fractionToPointAnd2Derivatives(fraction: number, result?: Plane3dByOriginAndVectors): undefined | Plane3dByOriginAndVectors Abstract Inherited CurvePrimitive Return a plane with
fractionToPointAndDerivative(fraction: number, result?: Ray3d): Ray3d Abstract Inherited CurvePrimitive Return the point (x,y,z) and derivative on the curve at fractional position.
fractionToPointAndUnitTangent(fraction: number, result?: Ray3d): Ray3d Inherited CurvePrimitive Returns a ray whose origin is the curve point and direction is the unit tangent.
fractionToSignedXYRadiusOfCurvature(fraction: number): number Inherited CurvePrimitive Construct signed distance from a point on the planar curve to its center of curvature (in xy only).
getFractionToDistanceScale(): undefined | number Inherited CurvePrimitive If the curve primitive has distance-along-curve strictly proportional to curve fraction, return the scale factor.
isAlmostEqual(other: GeometryQuery): boolean Inherited CurvePrimitive Test for exact structure and nearly identical geometry.
isPhysicallyClosedCurve(tolerance: number = Geometry.smallMetricDistance, xyOnly: boolean = false): boolean Inherited CurvePrimitive Whether the start and end points are defined and within tolerance.
isSameGeometryClass(other: GeometryQuery): boolean Abstract Inherited CurvePrimitive Test if (other instanceof this.Type).
moveSignedDistanceFromFraction(startFraction: number, signedDistance: number, allowExtension: boolean, result?: CurveLocationDetail): CurveLocationDetail Inherited CurvePrimitive (Attempt to) find a position on the curve at a signed distance from start fraction.
moveSignedDistanceFromFractionGeneric(startFraction: number, signedDistance: number, allowExtension: boolean, result?: CurveLocationDetail): CurveLocationDetail Protected Inherited CurvePrimitive Generic algorithm to search for point at signed distance from a fractional startPoint.
range(transform?: Transform, result?: Range3d): Range3d Inherited CurvePrimitive Return the range of the entire GeometryQuery tree.
rangeBetweenFractions(fraction0: number, fraction1: number, transform?: Transform): Range3d Inherited CurvePrimitive Returns the range of the curve between fractional positions.
rangeBetweenFractionsByClone(fraction0: number, fraction1: number, transform?: Transform): Range3d Inherited CurvePrimitive Returns a high accuracy range of the curve between fractional positions using clonePartialCurve.
rangeBetweenFractionsByCount(fraction0: number, fraction1: number, count: number, transform?: Transform, extrapolationFactor: number = 0.0): Range3d Inherited CurvePrimitive Returns an approximate range based on a fixed number of evaluations.
tryTransformInPlace(transform: Transform): boolean Abstract Inherited CurvePrimitive Attempt to transform in place.
tryTranslateInPlace(dx: number, dy: number = 0.0, dz: number = 0.0): boolean Inherited CurvePrimitive Try to move the geometry by dx,dy,dz.
areAlmostEqual(a: GeometryQuery, b: GeometryQuery): boolean Static Inherited CurvePrimitive Apply instance method isAlmostEqual if both are defined.
installStrokeCountMap(curve: CurvePrimitive, curveMap: StrokeCountMap, parentMap?: StrokeCountMap): void Static Inherited CurvePrimitive Final install step to save curveMap in curve.

Properties

Name Type Description
_polygon Protected Bezier1dNd Control points  
_workCoffsA Protected Float64Array | undefined scratch array for use by derived classes, using allocateAndZeroBezierWorkData for sizing.  
_workCoffsB Protected Float64Array | undefined scratch array for use by derived classes, using allocateAndZeroBezierWorkData for sizing.  
_workData0 Protected Float64Array scratch data blocks accessible by concrete class.  
_workData1 Protected Float64Array scratch data blocks accessible by concrete class.  
_workPoint0 Protected Point3d Scratch xyz point accessible by derived classes.  
_workPoint1 Protected Point3d Scratch xyz point accessible by derived classes.  
curvePrimitiveType Readonly "bezierCurve" String name for schema properties  
degree Accessor ReadOnly number (property accessor) Return the polynomial degree (one less than order)  
numPoles Accessor ReadOnly number (property accessor) Return the number of poles (aka control points)  
order Accessor ReadOnly number (property accessor) Return the polynomial order  

Inherited properties

Name Type Inherited from Description
children Accessor Inherited ReadOnly undefined | GeometryQuery[] CurvePrimitive Return GeometryQuery children for recursive queries.
* leaf classes do not need to implement.
geometryCategory Readonly Inherited "curvePrimitive" CurvePrimitive String name for schema properties
isExtensibleFractionSpace Accessor Inherited ReadOnly boolean CurvePrimitive * Returns true if the curve can be easily extended past its start/end point (i.e., beyond the usual
fraction space [0,1]). Otherwise, returns false.
* Base class default implementation returns false.
* These classes (and perhaps others in the future) will return true:
* LineSegment3d
* LineString3d
* Arc3d
parent Inherited any | undefined CurvePrimitive Data attached by various algorithms (e.g.
strokeData Inherited StrokeCountMap | undefined CurvePrimitive Data attached during stroking for facets.

Defined in

Last Updated: 28 October, 2025