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.  
computeStrokeCountForOptions(options?: StrokeOptions): number Assess length and turn to determine a stroke count.  
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(): 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
* ( The parent range should have been previously defined with setInterval)
 
getPolePoint3d(i: number, point?: Point3d): Point3d | undefined Abstract Get pole i as a Point3d.  
getPolePoint4d(i: number, point?: Point4d): Point4d | undefined 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.  
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(): Point3d Return the start point.  

Inherited methods

Name Inherited from Description
addMappedStrokesToLineString3D(map: StrokeCountMap, linestring: LineString3d): number CurvePrimitive * evaluate strokes at fractions indicated in a StrokeCountMap.
announceClipIntervals(_clipper: Clipper, _announce?: AnnounceNumberNumberCurvePrimitive): boolean CurvePrimitive Find intervals of this curvePrimitive that are interior to a clipper
appendPlaneIntersectionPoints(plane: PlaneAltitudeEvaluator, result: CurveLocationDetail[]): number CurvePrimitive Compute intersections with a plane.
clone(): GeometryQuery | undefined Abstract GeometryQuery return a clone
clonePartialCurve(_fractionA: number, _fractionB: number): CurvePrimitive | undefined CurvePrimitive Return (if possible) a curve primitive which is a portion of this curve.
cloneTransformed(transform: Transform): GeometryQuery | undefined Abstract GeometryQuery return a transformed clone.
closestPoint(spacePoint: Point3d, extend: VariantCurveExtendParameter): CurveLocationDetail | undefined CurvePrimitive Search for the curve point that is closest to the spacePoint.
computeAndAttachRecursiveStrokeCounts(options?: StrokeOptions, parentMap?: StrokeCountMap): void CurvePrimitive attach StrokeCountMap structure to this primitive (and recursively to any children)
* Base class implementation (here) gets the simple count from computeStrokeCountForOptions and attaches it.
curveLength(): number CurvePrimitive return the length of the curve.
curveLengthBetweenFractions(fraction0: number, fraction1: number): number CurvePrimitive Returns a (high accuracy) length of the curve between fractional positions
* Curve length is always positive.
curveLengthWithFixedIntervalCountQuadrature(fraction0: number, fraction1: number, numInterval: number, numGauss: number = 5): number CurvePrimitive Run an integration (with a default gaussian quadrature) with a fixed fractional step
This is typically called by specific curve type implementations of curveLengthBetweenFractions.
dispatchToGeometryHandler(handler: GeometryHandler): any Abstract GeometryQuery * "double dispatch" call pattern.
fractionAndDistanceToPointOnTangent(fraction: number, distance: number): Point3d CurvePrimitive Construct a point extrapolated along tangent at fraction.
fractionToFrenetFrame(fraction: number, result?: Transform): Transform | undefined CurvePrimitive Construct a frenet frame:
origin at the point on the curve
x axis is unit vector along the curve (tangent)
* y axis is perpendicular and in the plane of the osculating circle.
fractionToPoint(fraction: number, result?: Point3d): Point3d Abstract CurvePrimitive Return the point (x,y,z) on the curve at fractional position.
fractionToPointAnd2Derivatives(fraction: number, result?: Plane3dByOriginAndVectors): Plane3dByOriginAndVectors | undefined Abstract CurvePrimitive Return a plane with

origin at fractional position along the curve
vectorU is the first derivative, i.e.
fractionToPointAndDerivative(fraction: number, result?: Ray3d): Ray3d Abstract CurvePrimitive Return the point (x,y,z) and derivative on the curve at fractional position.
fractionToPointAndUnitTangent(fraction: number, result?: Ray3d): Ray3d CurvePrimitive Returns a ray whose origin is the curve point and direction is the unit tangent.
getFractionToDistanceScale(): number | undefined CurvePrimitive If the curve primitive has distance-along-curve strictly proportional to curve fraction, return true
If distance-along-the-curve is not proportional, return undefined.
isAlmostEqual(other: GeometryQuery): boolean GeometryQuery test for exact structure and nearly identical geometry.
isSameGeometryClass(other: GeometryQuery): boolean Abstract GeometryQuery test if (other instanceof this.Type).
moveSignedDistanceFromFraction(startFraction: number, signedDistance: number, allowExtension: boolean, result?: CurveLocationDetail): CurveLocationDetail 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 CurvePrimitive Generic algorithm to search for point at signed distance from a fractional startPoint.
range(transform?: Transform, result?: Range3d): Range3d GeometryQuery return the range of the entire (tree) GeometryQuery
tryTransformInPlace(transform: Transform): boolean Abstract GeometryQuery Attempt to transform in place.
tryTranslateInPlace(dx: number, dy: number = 0, dz: number = 0): boolean GeometryQuery try to move the geometry by dx,dy,dz
installStrokeCountMap(curve: CurvePrimitive, curveMap: StrokeCountMap, parentMap?: StrokeCountMap): void Static CurvePrimitive final install step to save curveMap in curve.

Properties

Name Type Description
_polygon Protected Bezier1dNd Control points  
_workCoffsA Protected undefined | Float64Array scratch array for use by derived classes, using allocateAndZeroBezierWorkData for sizing.  
_workCoffsB Protected undefined | Float64Array 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 "bezierCurve" = "bezierCurve"    
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 ReadOnly GeometryQuery[] | undefined GeometryQuery return GeometryQuery children for recursive queries.

* leaf classes do not need to implement.
geometryCategory "curvePrimitive" = "curvePrimitive" CurvePrimitive  
isExtensibleFractionSpace Accessor ReadOnly boolean CurvePrimitive Returns true if the curve's fraction queries extend beyond 0..1.
Base class default implementation returns false.
These class (and perhaps others in the future) will return true:
LineSegment3d
LineString3d
Arc3d
strokeData undefined | StrokeCountMap CurvePrimitive data attached during stroking for facets.

Defined in

Last Updated: 20 September, 2019