Class CubicBezierCurve

Classdesc

A refactored cubic bezier curve class.

Requires

Bounds

Requires

Vertex

Requires

Vector

Requires

XYCoords

Requires

UID

Requires

UIDGenerator

Implements

PathSegment

Constructors

constructor

new CubicBezierCurve(startPoint, endPoint, startControlPoint, endControlPoint): CubicBezierCurve
The constructor.
Parameters
- startPoint: Vertex
  The Bézier curve's start point.
- endPoint: Vertex
  The Bézier curve's end point.
- startControlPoint: Vertex
  The Bézier curve's start control point.
- endControlPoint: Vertex
  The Bézier curve's end control point.
Returns CubicBezierCurve
Name
CubicBezierCurve
- Defined in src/ts/CubicBezierCurve.ts:151

Properties

`Readonly` END_CONTROL_POINT

END_CONTROL_POINT: number = CubicBezierCurve.END_CONTROL_POINT

Constant

`Readonly` END_POINT

END_POINT: number = CubicBezierCurve.END_POINT

Constant

`Readonly` START_CONTROL_POINT

START_CONTROL_POINT: number = CubicBezierCurve.START_CONTROL_POINT

Constant

`Readonly` START_POINT

START_POINT: number = CubicBezierCurve.START_POINT

Constant

arcLength

arcLength: number

Member

Memberof

CubicBezierCurve

Instance

curveIntervals

curveIntervals: number

Member

Memberof

CubicBezierCurve

Instance

endControlPoint

endControlPoint: Vertex

Member

Memberof

CubicBezierCurve

Instance

endPoint

endPoint: Vertex

Member

Memberof

CubicBezierCurve

Instance

isDestroyed

isDestroyed: boolean

Member

isDestroyed

Memberof

CubicBezierCurve

Instance

segmentCache

segmentCache: Vertex[]

Member

Memberof

CubicBezierCurve

Instance

segmentLengths

segmentLengths: number[]

Member

Memberof

CubicBezierCurve

Instance

startControlPoint

startControlPoint: Vertex

Member

Memberof

CubicBezierCurve

Instance

startPoint

startPoint: Vertex

Member

Memberof

CubicBezierCurve

Instance

`Readonly` uid

uid: string

The UID of this drawable object.

Member

Memberof

CubicBezierCurve

Instance

`Static` `Readonly` END_CONTROL_POINT

END_CONTROL_POINT: number = 2

Constant

`Static` `Readonly` END_POINT

END_POINT: number = 3

Constant

`Static` `Readonly` START_CONTROL_POINT

START_CONTROL_POINT: number = 1

Constant

`Static` `Readonly` START_POINT

START_POINT: number = 0

Constant

`Static` `Private` utils

utils: {
getSubCurvePointsAt: ((curve, tStart, tEnd) => [Vertex, Vertex, Vertex, Vertex]);
} = ...

Helper utils.

Type declaration

getSubCurvePointsAt: ((curve, tStart, tEnd) => [Vertex, Vertex, Vertex, Vertex])
Get the points of a sub curve at the given start end end offsets (values between 0.0 and 1.0).

tStart >= tEnd is allowed, you will get a reversed sub curve then.

Method
getSubCurvePointsAt

Instance
Memberof
CubicBezierCurve

Returns
The sub curve as a new curve.
- - (curve, tStart, tEnd): [Vertex, Vertex, Vertex, Vertex]
  - Parameters
    - curve: CubicBezierCurve
      – The curve to get the sub curve points from.
    - tStart: number
      – The start offset of the desired sub curve (must be in [0..1]).
    - tEnd: number
      – The end offset if the desired cub curve (must be in [0..1]).
    Returns [Vertex, Vertex, Vertex, Vertex]

Methods

clone

clone(): CubicBezierCurve
Clone this Bézier curve (deep clone).

Returns CubicBezierCurve
Method
clone

Instance
Memberof
CubicBezierCurve
Implementation of PathSegment.clone
- Defined in src/ts/CubicBezierCurve.ts:716

convertU2T

convertU2T(u): number
Convert a relative curve position u to the absolute curve position t.
Parameters
- u: number
  The relative position on the curve in [0,arcLength].
Returns number
Method
convertU2t

Instance
Memberof
CubicBezierCurve
- Defined in src/ts/CubicBezierCurve.ts:658

destroy

destroy(): void
This function should invalidate any installed listeners and invalidate this object. After calling this function the object might not hold valid data any more and should not be used.

Returns void
- Defined in src/ts/CubicBezierCurve.ts:780

equals

equals(curve): boolean
Check if this and the specified curve are equal.

All four points need to be equal for this, the Vertex.equals function is used.

Please note that this function is not type safe (comparison with any object will fail).
Parameters
- curve: CubicBezierCurve
  The curve to compare with.
Returns boolean
Method
clone

Instance
Memberof
CubicBezierCurve
- Defined in src/ts/CubicBezierCurve.ts:762

getBounds

getBounds(): Bounds
Get the bounds of this bezier curve.

The bounds are approximated by the underlying segment buffer; the more segment there are, the more accurate will be the returned bounds.

Returns Bounds
The bounds of this curve.
- Defined in src/ts/CubicBezierCurve.ts:369

getClosestT

getClosestT(p): number
Get a 't' (relative position on curve) with the closest distance to point 'p'.

The returned number is 0.0 <= t <= 1.0. Use the getPointAt(t) function to retrieve the actual curve point.

This function uses a recursive approach by cutting the curve into several linear segments.
Parameters
- p: Vertex
  The point to find the closest position ('t' on the curve).
Returns number
- Defined in src/ts/CubicBezierCurve.ts:307

getEndControlPoint

getEndControlPoint(): Vertex
Get the end control point of the curve.

This function just returns this.endControlPoint.

Returns Vertex
this.endControlPoint

Method
getEndControlPoint

Instance
Memberof
CubicBezierCurve
- Defined in src/ts/CubicBezierCurve.ts:435

getEndPoint

getEndPoint(): Vertex
Get the end point of the curve.

This function just returns this.endPoint.

Returns Vertex
this.endPoint

Method
getEndPoint

Instance
Memberof
CubicBezierCurve
Implementation of PathSegment.getEndPoint
- Defined in src/ts/CubicBezierCurve.ts:407

getEndTangent

getEndTangent(): Vertex
Get the tangent's end point at the end point of this segment.

Returns Vertex
The end point of the ending point's tangent.

Method
getEndTangent

Memberof
PathSegment
Implementation of PathSegment.getEndTangent
- Defined in src/ts/CubicBezierCurve.ts:744

getLength

getLength(): number
Get the total curve length.

As not all Bézier curved have a closed formula to calculate their lengths, this implementation uses a segment buffer (with a length of 30 segments). So the returned length is taken from the arc segment buffer.

Note that if the curve points were changed and the segment buffer was not updated this function might return wrong (old) values.

Returns number

= 0

Method
getLength

Instance
Memberof
CubicBezierCurve
- Defined in src/ts/CubicBezierCurve.ts:250

getPerpendicular

getPerpendicular(u): Vertex
Get the curve perpendicular at a given relative position u in [0,arcLength] as a vector.

Note that the returned vector (end point) is not normalized.
Parameters
- u: number
  The relative position on the curve in [0,arcLength].
Returns Vertex
Method
getPerpendicular

Instance
Memberof
CubicBezierCurve
- Defined in src/ts/CubicBezierCurve.ts:688

getPerpendicularAt

getPerpendicularAt(t): Vertex
Get the curve perpendicular at a given absolute position t in [0,1] as a vector.

Note that the returned vector (end point) is not normalized.
Parameters
- t: number
Returns Vertex
Method
getPerpendicularAt

Instance
Memberof
CubicBezierCurve
- Defined in src/ts/CubicBezierCurve.ts:703

getPoint

getPoint(u): Vertex
Get the curve point at a given position u, where u is in [0,arcLength].
Parameters
- u: number
  The position on the curve in [0,arcLength] (0 means at start point, arcLength means at end point, other values address points in bertween).
Returns Vertex
See
CubicBezierCurve.getPointAt

Method
getPoint

Instance
Memberof
CubicBezierCurve
- Defined in src/ts/CubicBezierCurve.ts:495

getPointAt

getPointAt(t): Vertex
Get the curve point at a given position t, where t is in [0,1].
Parameters
- t: number
  The position on the curve in [0,1] (0 means at start point, 1 means at end point, other values address points in bertween).
Returns Vertex
See
Line.pointAt

Method
getPointAt

Instance
Memberof
CubicBezierCurve
- Defined in src/ts/CubicBezierCurve.ts:468

getPointByID

getPointByID(id): Vertex
Get one of the four curve points specified by the passt point ID.
Parameters
- id: number
  One of START_POINT, START_CONTROL_POINT, END_CONTROL_POINT or END_POINT.
Returns Vertex
Method
getEndControlPoint

Instance
Memberof
CubicBezierCurve
- Defined in src/ts/CubicBezierCurve.ts:448

getStartControlPoint

getStartControlPoint(): Vertex
Get the start control point of the curve.

This function just returns this.startControlPoint.

Returns Vertex
this.startControlPoint

Method
getStartControlPoint

Instance
Memberof
CubicBezierCurve
- Defined in src/ts/CubicBezierCurve.ts:421

getStartPoint

getStartPoint(): Vertex
Get the start point of the curve.

This function just returns this.startPoint.

Returns Vertex
this.startPoint

Method
getStartPoint

Instance
Memberof
CubicBezierCurve
Implementation of PathSegment.getStartPoint
- Defined in src/ts/CubicBezierCurve.ts:393

getStartTangent

getStartTangent(): Vertex
Get the tangent's end point at the start point of this segment.

Returns Vertex
The end point of the starting point's tangent.

Method
getStartTangent

Memberof
PathSegment
Implementation of PathSegment.getStartTangent
- Defined in src/ts/CubicBezierCurve.ts:733

getSubCurve

getSubCurve(uStart, uEnd): CubicBezierCurve
Get a sub curve at the given start end end positions (values on the curve's length, between 0 and curve.arcLength).

tStart >= tEnd is allowed, you will get a reversed sub curve then.
Parameters
- uStart: number
- uEnd: number
Returns CubicBezierCurve
The sub curve as a new curve.

Method
getSubCurve

Instance
Memberof
CubicBezierCurve
- Defined in src/ts/CubicBezierCurve.ts:614

getSubCurveAt

getSubCurveAt(tStart, tEnd): CubicBezierCurve
Get a sub curve at the given start end end offsets (values between 0.0 and 1.0).

tStart >= tEnd is allowed, you will get a reversed sub curve then.
Parameters
- tStart: number
  – The start offset of the desired sub curve (must be in [0..1]).
- tEnd: number
  – The end offset if the desired cub curve (must be in [0..1]).
Returns CubicBezierCurve
The sub curve as a new curve.

Method
getSubCurveAt

Instance
Memberof
CubicBezierCurve
- Defined in src/ts/CubicBezierCurve.ts:630

getTangent

getTangent(u): Vertex
Get the curve tangent vector at a given relative position u in [0,arcLength].

Note that the returned tangent vector (end point) is not normalized.
Parameters
- u: number
  The position on the curve in [0,arcLength].
Returns Vertex
Method
getTangent

Instance
Memberof
CubicBezierCurve
- Defined in src/ts/CubicBezierCurve.ts:673

getTangentAt

getTangentAt(t): Vertex
Get the curve tangent vector at a given absolute curve position t in [0,1].

Note that the returned tangent vector (end point) is not normalized and relative to (0,0).
Parameters
- t: number
  The position on the curve in [0,1].
Returns Vertex
Method
getTangent

Instance
Memberof
CubicBezierCurve
- Defined in src/ts/CubicBezierCurve.ts:510

`Private` locateIntervalByDistance

locateIntervalByDistance(p, tStart, tEnd, stepCount): {
    t: number;
    tNext: number;
    tPrev: number;
}
This helper function locates the 't' on a fixed step interval with the minimal distance between the curve (at 't') and the given point.

Furthermore you must specify a sub curve (start 't' and end 't') you want to search on. Using tStart=0.0 and tEnd=1.0 will search on the full curve.
Parameters
- p: Vertex
  The point to find the closest curve point for.
- tStart: number
  The start position (start 't' of the sub curve). Should be >= 0.0.
- tEnd: number
  The end position (end 't' of the sub curve). Should be <= 1.0.
- stepCount: number
  The number of steps to check within the interval.
Returns {
    t: number;
    tNext: number;
    tPrev: number;
}
- An object with t, tPrev and tNext (numbers).
- t: number
- tNext: number
- tPrev: number
- Defined in src/ts/CubicBezierCurve.ts:335

moveCurvePoint

moveCurvePoint(pointID, moveAmount, moveControlPoint, updateArcLengths): void
Move the given curve point (the start point, end point or one of the two control points).
Parameters
- pointID: number
  The numeric identicator of the point to move. Use one of the four eBezierPoint constants.
- moveAmount: XYCoords
  The amount to move the specified point by.
- moveControlPoint: boolean
  Move the control points along with their path point (if specified point is a path point).
- updateArcLengths: boolean
  Specifiy if the internal arc segment buffer should be updated.
Returns void
Method
moveCurvePoint

Instance
Memberof
CubicBezierCurve
- Defined in src/ts/CubicBezierCurve.ts:181

reverse

reverse(): CubicBezierCurve
Reverse this curve, means swapping start- and end-point and swapping start-control- and end-control-point.

Returns CubicBezierCurve
this (for chaining).

Method
reverse

Instance
Memberof
CubicBezierCurve
Implementation of PathSegment.reverse
- Defined in src/ts/CubicBezierCurve.ts:225

toJSON

toJSON(prettyFormat?): string
Convert this curve to a JSON string.
Parameters
- Optional prettyFormat: boolean
  If set to true the function will add line breaks.
Returns string
The JSON data.

Method
toJSON

Instance
Memberof
CubicBezierCurve
- Defined in src/ts/CubicBezierCurve.ts:823

translate

translate(amount): CubicBezierCurve
Translate the whole curve by the given {x,y} amount: moves all four points.
Parameters
- amount: Vertex
  The amount to translate this curve by.
Returns CubicBezierCurve
this (for chaining).

Method
translate

Instance
Memberof
CubicBezierCurve
- Defined in src/ts/CubicBezierCurve.ts:208

trimEnd

trimEnd(uValue): CubicBezierCurve
Trim off the end of this curve. The position parameter uValue is the absolute position on the curve in [0...arcLength]. The remaining curve will be the one in the bounds [0,uValue] (so [1.0-uValue,1.0] is cut off).

Note this function just converts the absolute parameter to a relative one and call trimEndAt.
Parameters
- uValue: number
  The absolute position parameter where to cut off the tail curve.
Returns CubicBezierCurve
this for chanining.

Method
trimEnd

Instance
Memberof
CubicBezierCurve
- Defined in src/ts/CubicBezierCurve.ts:578

trimEndAt

trimEndAt(t): CubicBezierCurve
Trim off the end of this curve. The position parameter t is the relative position in [0..1]. The remaining curve will be the one in the bounds [0,t] (so [1.0-t,1.0] is cut off).
Parameters
- t: number
  The relative position parameter where to cut off the tail curve.
Returns CubicBezierCurve
this for chanining.

Method
trimEndAt

Instance
Memberof
CubicBezierCurve
- Defined in src/ts/CubicBezierCurve.ts:592

trimStart

trimStart(uValue): CubicBezierCurve
Trim off a start section of this curve. The position parameter uValue is the absolute position on the curve in [0...arcLength]. The remaining curve will be the one in the bounds [uValue,1] (so [0.0,uValue] is cut off).

Note this function just converts the absolute parameter to a relative one and call trimStartAt.
Parameters
- uValue: number
  The absolute position parameter where to cut off the head curve.
Returns CubicBezierCurve
this for chanining.

Method
trimStart

Instance
Memberof
CubicBezierCurve
- Defined in src/ts/CubicBezierCurve.ts:541

trimStartAt

trimStartAt(t): CubicBezierCurve
Trim off a start section of this curve. The position parameter t is the relative position in [0..1]. The remaining curve will be the one in the bounds [uValue,1] (so [0.0,uValue] is cut off).
Parameters
- t: number
  The relative position parameter where to cut off the head curve.
Returns CubicBezierCurve
this for chanining.

Method
trimStartAt

Instance
Memberof
CubicBezierCurve
- Defined in src/ts/CubicBezierCurve.ts:555

updateArcLengths

updateArcLengths(): void
Uptate the internal arc segment buffer and their lengths.

All class functions update the buffer automatically; if any curve point is changed by other reasons you should call this function to keep actual values in the buffer.

Returns void
Method
updateArcLengths

Instance
Memberof
CubicBezierCurve
- Defined in src/ts/CubicBezierCurve.ts:266

`Static` fromArray

fromArray(arr): CubicBezierCurve
Convert a 4-element array of vertices to a cubic bézier curve.
Parameters
- arr: Vertex[]
  [ startVertex, endVertex, startControlVertex, endControlVertex ]
Returns CubicBezierCurve
Method
fromArray

Memberof
CubicBezierCurve

Throws
An exception if the passed array is malformed.
- Defined in src/ts/CubicBezierCurve.ts:905

`Static` fromJSON

fromJSON(jsonString): CubicBezierCurve
Parse a Bézier curve from the given JSON string.
Parameters
- jsonString: string
  The JSON data to parse.
Returns CubicBezierCurve
Method
fromJSON

Memberof
CubicBezierCurve

Static
Throws
An exception if the JSON string is malformed.
- Defined in src/ts/CubicBezierCurve.ts:865

`Static` fromObject

fromObject(obj): CubicBezierCurve
Try to convert the passed object to a CubicBezierCurve.
Parameters
- obj: any
  The object to convert.
Returns CubicBezierCurve
Method
fromObject

Memberof
CubicBezierCurve

Static
Throws
An exception if the passed object is malformed.
- Defined in src/ts/CubicBezierCurve.ts:880

`Static` isInstance

isInstance(obj): boolean
Quick check for class instance. Is there a better way?
Parameters
- obj: any
  Check if the passed object/value is an instance of CubicBezierCurve.
Returns boolean
Method
isInstance

Instance
Memberof
CubicBezierCurve
- Defined in src/ts/CubicBezierCurve.ts:798

Class CubicBezierCurve

Classdesc

Requires

Requires

Requires

Requires

Requires

Requires

Implements

Index

Constructors

Properties

Methods

Constructors

constructor

Parameters

Returns CubicBezierCurve

Name

Properties

Readonly END_CONTROL_POINT

Constant

Readonly END_POINT

Constant

Readonly START_CONTROL_POINT

Constant

Readonly START_POINT

Constant

arcLength

Member

Memberof

Instance

curveIntervals

Member

Memberof

Instance

endControlPoint

Member

Memberof

Instance

endPoint

Member

Memberof

Instance

isDestroyed

Member

Memberof

Instance

segmentCache

Member

Memberof

Instance

segmentLengths

Member

Memberof

Instance

startControlPoint

Member

Memberof

Instance

startPoint

Member

Memberof

Instance

Readonly uid

Member

Memberof

Instance

Static Readonly END_CONTROL_POINT

Constant

Static Readonly END_POINT

Constant

Static Readonly START_CONTROL_POINT

Constant

Static Readonly START_POINT

Constant

Static Private utils

Type declaration

getSubCurvePointsAt: ((curve, tStart, tEnd) => [Vertex, Vertex, Vertex, Vertex])

Method

Instance

`Readonly` END_CONTROL_POINT

`Readonly` END_POINT

`Readonly` START_CONTROL_POINT

`Readonly` START_POINT

`Readonly` uid

`Static` `Readonly` END_CONTROL_POINT

`Static` `Readonly` END_POINT

`Static` `Readonly` START_CONTROL_POINT

`Static` `Readonly` START_POINT

`Static` `Private` utils