Class Polygon

constructor

• new Polygon(vertices?, isOpen?): Polygon

• The constructor.

  Parameters

  • Optional vertices: Vertex[]

    An array of 2d vertices that shape the polygon.
  • Optional isOpen: boolean

    Indicates if the polygon should be rendered as an open or closed shape.

  Returns Polygon

  Name

  Polygon

Readonly className

isDestroyed

isOpen

Readonly uid

vertices

Static utils

addVertex

• addVertex(vert): void

• Add a vertex to the end of the vertices array.

  Parameters

  • vert: Vertex

    The vertex to add.

  Returns void

  Method

  addVert

  Instance

  Memberof

  Polygon

area

• area(): number

• Calculate the area of the given polygon (unsigned).

  Note that this does not work for self-intersecting polygons.

  Returns number

  Method

  area

  Instance

  Memberof

  Polygon

clone

• clone(): Polygon

• Create a deep copy of this polygon.

  Returns Polygon

  The cloned polygon.

closestLineIntersection

• closestLineIntersection(line, inVectorBoundsOnly?): Vertex

• Get the closest line-polygon-intersection point (closest the line point A).

  See demo 47-closest-vector-projection-on-polygon for how it works.

  Parameters

  • line: VertTuple<any>

    The line to find intersections with.
  • inVectorBoundsOnly: boolean = false

    If set to true only intersecion points on the passed vector are considered (located strictly between start and end vertex).

  Returns Vertex

  • An array of all intersections within the polygon bounds.

containsPolygon

• containsPolygon(polygon): boolean

• Check if the passed polygon is completly contained inside this polygon.

  This means:

  • all polygon's vertices must be inside this polygon.
  • the polygon has no edge intersections with this polygon.

  Parameters

  • polygon: Polygon

    The polygon to check if contained.

  Returns boolean

containsVert

• containsVert(vert): boolean

• Check if the given vertex is inside this polygon.
  
  Ray-casting algorithm found at
  https://stackoverflow.com/questions/22521982/check-if-point-inside-a-polygon

  Parameters

  • vert: XYCoords

    The vertex to check. The new x-component.

  Returns boolean

  True if the passed vertex is inside this polygon. The polygon is considered closed.

  Method

  containsVert

  Instance

  Memberof

  Polygon

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

getBounds

• getBounds(): Bounds

• Get the bounding box (bounds) of this polygon.

  Returns Bounds

  The rectangular bounds of this polygon.

  Method

  getBounds

  Instance

  Memberof

  Polygon

getEvenDistributionPolygon

• getEvenDistributionPolygon(pointCount): Polygon

• Convert this polygon into a new polygon with n evenly distributed vertices.

  Parameters

  • pointCount: number

    Must not be negative.

  Returns Polygon

getInterpolationPolygon

• getInterpolationPolygon(interpolationCount): Polygon

• Construct a new polygon from this polygon with more vertices on each edge. The interpolation count determines the number of additional vertices on each edge. An interpolation count of 0 will return a polygon that equals the source polygon.

  Parameters

  • interpolationCount: number

  Returns Polygon

  A polygon with interpolationCount more vertices (as as factor).

getVertexAt

• getVertexAt(index): Vertex

• Get the polygon vertex at the given position (index).

  The index may exceed the total vertex count, and will be wrapped around then (modulo).

  For k >= 0:

  • getVertexAt( vertices.length ) == getVertexAt( 0 )
  • getVertexAt( vertices.length + k ) == getVertexAt( k )
  • getVertexAt( -k ) == getVertexAt( vertices.length -k )

  Parameters

  • index: number

    The index of the desired vertex.

  Returns Vertex

  At the given index.

  Metho

  getVertexAt

  Instance

  Memberof

  Polygon

isClockwise

• isClockwise(): boolean

• Get the winding order of this polgon: clockwise or counterclockwise.

  Returns boolean

  Method

  isClockwise

  Instance

  Memberof

  Polygon

lineIntersections

• lineIntersections(line, inVectorBoundsOnly?): Vertex[]

• Get all line intersections with this polygon.

  See demo 47-closest-vector-projection-on-polygon for how it works.

  Parameters

  • line: VertTuple<any>

    The line to find intersections with.
  • inVectorBoundsOnly: boolean = false

    If set to true only intersecion points on the passed vector are returned (located strictly between start and end vertex).

  Returns Vertex[]

  • An array of all intersections within the polygon bounds.

move

• move(amount): Polygon

• Move the polygon's vertices by the given amount.

  Parameters

  • amount: XYCoords

    The amount to move.

  Returns Polygon

  this for chaining

  Method

  move

  Instance

  Memberof

  Polygon

perimeter

• perimeter(): number

• Get the perimeter of this polygon. The perimeter is the absolute length of the outline.

  If this polygon is open then the last segment (connecting the first and the last vertex) will be skipped.

  Returns number

  Method

  perimeter

  Instance

  Memberof

  Polygon

rotate

• rotate(angle, center): Polygon

• Rotate the polygon around the given center.

  Parameters

  • angle: number

    The rotation angle.
  • center: Vertex

    The center of rotation.

  Returns Polygon

  this, for chaining.

  Method

  rotate

  Instance

  Memberof

  Polygon

scale

• scale(factor, center): Polygon

• Scale the polygon relative to the given center.

  Parameters

  • factor: number

    The scale factor.
  • center: Vertex

    The center of scaling.

  Returns Polygon

  this, for chaining.

  Method

  scale

  Instance

  Memberof

  Polygon

signedArea

• signedArea(): number

• Calulate the signed polyon area by interpreting the polygon as a matrix and calculating its determinant.

  Returns number

  Method

  signedArea

  Instance

  Memberof

  Polygon

toCubicBezierData

• toCubicBezierData(threshold): Vertex[]

• Convert this polygon to a sequence of cubic Bézier curves.
  
  The first vertex in the returned array is the start point.
  The following sequence are triplets of (first-control-point, secnond-control-point, end-point):
  

  startPoint, controlPoint0_0, controlPoint1_1, pathPoint1, controlPoint1_0, controlPoint1_1, ..., endPoint

  Parameters

  • threshold: number

    An optional threshold (default=1.0) how strong the curve segments should over-/under-drive. Should be between 0.0 and 1.0 for best results but other values are allowed.

  Returns Vertex[]

  An array of 2d vertices that shape the cubic Bézier curve.

  Method

  toCubicBezierData

  Instance

  Memberof

  Polygon

toCubicBezierPath

• toCubicBezierPath(threshold): BezierPath

• Convert this polygon to a cubic bezier path instance.

  Parameters

  • threshold: number

    The threshold, usually from 0.0 to 1.0.

  Returns BezierPath

  • A bezier path instance.

  Method

  toCubicBezierPath

  Instance

  Memberof

  Polygon

toCubicBezierSVGString

• toCubicBezierSVGString(threshold): string

• Convert this polygon to a cubic bezier curve, represented as an SVG data string.

  Parameters

  • threshold: number

  Returns string

  The 'd' part for an SVG 'path' element.

  Method

  toCubicBezierSVGString

  Instance

  Memberof

  Polygon

toQuadraticBezierData

• toQuadraticBezierData(): Vertex[]

• Convert this polygon to a sequence of quadratic Bézier curves.
  
  The first vertex in the returned array is the start point.
  The following sequence are pairs of control-point-and-end-point:

  startPoint, controlPoint0, pathPoint1, controlPoint1, pathPoint2, controlPoint2, ..., endPoint

  Returns Vertex[]

  An array of 2d vertices that shape the quadratic Bézier curve.

  Method

  toQuadraticBezierData

  Instance

  Memberof

  Polygon

toQuadraticBezierSVGString

• toQuadraticBezierSVGString(): string

• Convert this polygon to a quadratic bezier curve, represented as an SVG data string.

  Returns string

  The 'd' part for an SVG 'path' element.

  Method

  toQuadraticBezierSVGString

  Instance

  Memberof

  Polygon