Class Polygon

constructor

• new Polygon(...args): Polygon

• Constructor creates new instance of polygon. With no arguments new polygon is empty.
  Constructor accepts as argument array that define loop of shapes or array of arrays in case of multi polygon
  Loop may be defined in different ways:
  

  • array of shapes of type Segment or Arc
    
  • array of points (Point)
    
  • array of numeric pairs which represent points
    
  • box or circle object
    Alternatively, it is possible to use polygon.addFace method

  Parameters

  • Rest...args:
        | []
        | [Point[]]
        | [[number, number][]]
        | [(Segment | Arc)[]]
        | [Box | Circle]
        | [(Segment | Arc)[][]]
        | [Point[][]]

    array of shapes or array of arrays

  Returns Polygon

edges

faces

box

• get box(): Box

• (Getter) Returns bounding box of the polygon

  Returns Box

name

• get name(): string

• Shape name

  Returns string

  name of the shape

vertices

• get vertices(): Point[]

• (Getter) Returns array of vertices

  Returns Point[]

addFace

• addFace(...args): Face

• Add new face to polygon. Returns added face

  Parameters

  • Rest...args:
        | [Point[]]
        | [[number, number][]]
        | [(Segment | Arc)[]]
        | [Box | Circle]
        | [Edge, Edge]

    new face may be create with one of the following ways:
    

    1. array of points that describe closed path (edges are segments)
       
    2. array of shapes (segments and arcs) which describe closed path
       
    3. circle - will be added as counterclockwise arc
       
    4. box - will be added as counterclockwise rectangle
       You can chain method face.reverse() is you need to change direction of the creates face

  Returns Face

area

• area(): number

• Returns area of the polygon. Area of an island will be added, area of a hole will be subtracted

  Returns number

clone

• clone(): Polygon

• Create new cloned instance of the polygon

  Returns Polygon

contains

• contains(shape): boolean

• Returns true if polygon contains shape: no point of shape lay outside of the polygon, false otherwise

  Parameters

  • shape: Shape<any>

    test shape

  Returns boolean

deleteFace

• deleteFace(face): boolean

• Delete existing face from polygon

  Parameters

  • face: Face

    Face to be deleted

  Returns boolean

distanceTo

• distanceTo(shape): [number, Segment]

• Return distance and shortest segment between polygon and other shape as array [distance, shortestSegment]

  Parameters

  • shape: Shape<any>

    Shape of one of the types Point, Circle, Line, Segment, Arc or Polygon

  Returns [number, Segment]

findEdgeByPoint

• findEdgeByPoint(pt): undefined | Edge

• Returns the first found edge of polygon that contains given point If point is a vertex, return the edge where the point is an end vertex, not a start one

  Parameters

  • pt: Point

  Returns undefined | Edge

intersect

• intersect(shape): Point[]

• Return array of intersection points between polygon and other shape

  Parameters

  • shape: Shape<any>

    Shape of the one of supported types
    

  Returns Point[]

isEmpty

• isEmpty(): boolean

• Return true is polygon has no edges

  Returns boolean

recreateFaces

• recreateFaces(): void

• Clear all faces and create new faces from edges

  Returns void

reverse

• reverse(): Polygon

• Reverse orientation of all faces to opposite

  Returns Polygon

rotate

• rotate(angle?, center?): Polygon

• Return new polygon rotated by given angle around given point If point omitted, rotate around origin (0,0) Positive value of angle defines rotation counterclockwise, negative - clockwise

  Parameters

  • angle: number = 0

    rotation angle in radians
  • center: Point = ...

    rotation center, default is (0,0)

  Returns Polygon

  new rotated polygon

scale

• scale(sx, sy): Polygon

• Return new polygon with coordinates multiplied by scaling factor

  Parameters

  • sx: number

    x-axis scaling factor
  • sy: number

    y-axis scaling factor

  Returns Polygon

transform

• transform(matrix?): Polygon

• Return new polygon transformed using affine transformation matrix

  Parameters

  • matrix: Matrix = ...

    affine transformation matrix

  Returns Polygon

  • new polygon

translate

• translate(...args): Polygon

• Returns new polygon translated by given vector

  Parameters

  • Rest...args: [number, number] | [Vector]

    Translation vector or translation by x and y

  Returns Polygon