Polygon

Phaser.Geom.Polygon

A Polygon object

The polygon is a closed shape consists of a series of connected straight lines defined by list of ordered points. Several formats are supported to define the list of points, check the setTo method for details. This is a geometry object allowing you to define and inspect the shape. It is not a Game Object, in that you cannot add it to the display list, and it has no texture. To render a Polygon you should look at the capabilities of the Graphics class.

Constructor

new Polygon([points])

Parameters

name

type

optional

description

points

string | Array.<number>

Array.<Phaser.Types.Math.Vector2Like>

Yes


Scope: static

Source: src/geom/polygon/Polygon.js#L12
Since: 3.0.0

Public Methods

calculateArea

<instance> calculateArea()

Description:

Calculates the area of the Polygon. This is available in the property Polygon.area

Returns: number - The area of the polygon.

Source: src/geom/polygon/Polygon.js#L160
Since: 3.0.0


Clone

<static> Clone(polygon)

Description:

Create a new polygon which is a copy of the specified polygon

Parameters:

name

type

optional

description

polygon

Phaser.Geom.Polygon

No

The polygon to create a clone of

Returns: Phaser.Geom.Polygon - A new separate Polygon cloned from the specified polygon, based on the same points.

Source: src/geom/polygon/Clone.js#L9
Since: 3.0.0


contains

<instance> contains(x, y)

Description:

Check to see if the Polygon contains the given x / y coordinates.

Parameters:

name

type

optional

description

x

number

No

The x coordinate to check within the polygon.

y

number

No

The y coordinate to check within the polygon.

Returns: boolean - true if the coordinates are within the polygon, otherwise false.

Source: src/geom/polygon/Polygon.js#L76
Since: 3.0.0


Contains

<static> Contains(polygon, x, y)

Description:

Checks if a point is within the bounds of a Polygon.

Parameters:

name

type

optional

description

polygon

Phaser.Geom.Polygon

No

The Polygon to check against.

x

number

No

The X coordinate of the point to check.

y

number

No

The Y coordinate of the point to check.

Returns: boolean - true if the point is within the bounds of the Polygon, otherwise false.

Source: src/geom/polygon/Contains.js#L10
Since: 3.0.0


ContainsPoint

<static> ContainsPoint(polygon, point)

Description:

Checks the given Point again the Polygon to see if the Point lays within its vertices.

Parameters:

name

type

optional

description

polygon

Phaser.Geom.Polygon

No

The Polygon to check.

point

Phaser.Geom.Point

No

The Point to check if it's within the Polygon.

Returns: boolean - true if the Point is within the Polygon, otherwise false.

Source: src/geom/polygon/ContainsPoint.js#L9
Since: 3.0.0


Earcut

<static> Earcut(data, [holeIndices], [dimensions])

Description:

This module implements a modified ear slicing algorithm, optimized by z-order curve hashing and extended to handle holes, twisted polygons, degeneracies and self-intersections in a way that doesn't guarantee correctness of triangulation, but attempts to always produce acceptable results for practical data.

Example:

const triangles = Phaser.Geom.Polygon.Earcut([10,0, 0,50, 60,60, 70,10]); // returns [1,0,3, 3,2,1]

Each group of three vertex indices in the resulting array forms a triangle.

// triangulating a polygon with a hole
earcut([0,0, 100,0, 100,100, 0,100,  20,20, 80,20, 80,80, 20,80], [4]);
// [3,0,4, 5,4,0, 3,4,7, 5,0,1, 2,3,7, 6,5,1, 2,7,6, 6,1,2]

// triangulating a polygon with 3d coords
earcut([10,0,1, 0,50,2, 60,60,3, 70,10,4], null, 3);
// [1,0,3, 3,2,1]

If you pass a single vertex as a hole, Earcut treats it as a Steiner point.

If your input is a multi-dimensional array (e.g. GeoJSON Polygon), you can convert it to the format expected by Earcut with Phaser.Geom.Polygon.Earcut.flatten:

var data = earcut.flatten(geojson.geometry.coordinates);
var triangles = earcut(data.vertices, data.holes, data.dimensions);

After getting a triangulation, you can verify its correctness with Phaser.Geom.Polygon.Earcut.deviation:

var deviation = earcut.deviation(vertices, holes, dimensions, triangles);

Returns the relative difference between the total area of triangles and the area of the input polygon. 0 means the triangulation is fully correct.

For more information see https://github.com/mapbox/earcut

Parameters:

name

type

optional

default

description

data

Array.<number>

No

A flat array of vertex coordinate, like [x0,y0, x1,y1, x2,y2, ...]

holeIndices

Array.<number>

Yes

An array of hole indices if any (e.g. [5, 8] for a 12-vertex input would mean one hole with vertices 5–7 and another with 8–11).

dimensions

number

Yes

2

The number of coordinates per vertex in the input array (2 by default).

Returns: Array.<number> - An array of triangulated data.

Source: src/geom/polygon/Earcut.js#L7
Since: 3.50.0


GetAABB

<static> GetAABB(polygon, [out])

Description:

Calculates the bounding AABB rectangle of a polygon.

Tags:

  • generic

Parameters:

name

type

optional

description

polygon

Phaser.Geom.Polygon

No

The polygon that should be calculated.

out

Phaser.Geom.Rectangle | object

Yes

The rectangle or object that has x, y, width, and height properties to store the result. Optional.

Returns: Phaser.Geom.Rectangle, object - The resulting rectangle or object that is passed in with position and dimensions of the polygon's AABB.

Source: src/geom/polygon/GetAABB.js#L9
Since: 3.0.0


GetNumberArray

<static> GetNumberArray(polygon, [output])

Description:

Stores all of the points of a Polygon into a flat array of numbers following the sequence [ x,y, x,y, x,y ], i.e. each point of the Polygon, in the order it's defined, corresponds to two elements of the resultant array for the point's X and Y coordinate.

Tags:

  • generic

Parameters:

name

type

optional

description

polygon

Phaser.Geom.Polygon

No

The Polygon whose points to export.

output

array | Array.<number>

Yes

An array to which the points' coordinates should be appended.

Returns: array, Array.<number> - The modified output array, or a new array if none was given.

Source: src/geom/polygon/GetNumberArray.js#L9
Since: 3.0.0


getPoints

<instance> getPoints(quantity, [stepRate], [output])

Description:

Returns an array of Point objects containing the coordinates of the points around the perimeter of the Polygon, based on the given quantity or stepRate values.

Tags:

  • generic

Parameters:

name

type

optional

description

quantity

number

No

The amount of points to return. If a falsey value the quantity will be derived from the stepRate instead.

stepRate

number

Yes

Sets the quantity by getting the perimeter of the Polygon and dividing it by the stepRate.

output

array | Array.<Phaser.Geom.Point>

Yes

An array to insert the points in to. If not provided a new array will be created.

Returns: array, Array.<Phaser.Geom.Point> - An array of Point objects pertaining to the points around the perimeter of the Polygon.

Source: src/geom/polygon/Polygon.js#L199
Since: 3.12.0


GetPoints

<static> GetPoints(polygon, quantity, [stepRate], [output])

Description:

Returns an array of Point objects containing the coordinates of the points around the perimeter of the Polygon, based on the given quantity or stepRate values.

Parameters:

name

type

optional

description

polygon

Phaser.Geom.Polygon

No

The Polygon to get the points from.

quantity

number

No

The amount of points to return. If a falsey value the quantity will be derived from the stepRate instead.

stepRate

number

Yes

Sets the quantity by getting the perimeter of the Polygon and dividing it by the stepRate.

output

array

Yes

An array to insert the points in to. If not provided a new array will be created.

Returns: Array.<Phaser.Geom.Point> - An array of Point objects pertaining to the points around the perimeter of the Polygon.

Source: src/geom/polygon/GetPoints.js#L11
Since: 3.12.0


Perimeter

<static> Perimeter(polygon)

Description:

Returns the perimeter of the given Polygon.

Parameters:

name

type

optional

description

polygon

Phaser.Geom.Polygon

No

The Polygon to get the perimeter of.

Returns: number - The perimeter of the Polygon.

Source: src/geom/polygon/Perimeter.js#L10
Since: 3.12.0


Reverse

<static> Reverse(polygon)

Description:

Reverses the order of the points of a Polygon.

Tags:

  • generic

Parameters:

name

type

optional

description

polygon

Phaser.Geom.Polygon

No

The Polygon to modify.

Returns: Phaser.Geom.Polygon - The modified Polygon.

Source: src/geom/polygon/Reverse.js#L7
Since: 3.0.0


setTo

<instance> setTo([points])

Description:

Sets this Polygon to the given points.

The points can be set from a variety of formats:

  • A string containing paired values separated by a single space: '40 0 40 20 100 20 100 80 40 80 40 100 0 50'
  • An array of Point objects: [new Phaser.Point(x1, y1), ...]
  • An array of objects with public x/y properties: [obj1, obj2, ...]
  • An array of paired numbers that represent point coordinates: [x1,y1, x2,y2, ...]
  • An array of arrays with two elements representing x/y coordinates: [[x1, y1], [x2, y2], ...]

setTo may also be called without any arguments to remove all points.

Parameters:

name

type

optional

description

points

string | Array.<number>

Array.<Phaser.Types.Math.Vector2Like>

Yes

Returns: Phaser.Geom.Polygon - This Polygon object.

Source: src/geom/polygon/Polygon.js#L92
Since: 3.0.0


Simplify

<static> Simplify(polygon, [tolerance], [highestQuality])

Description:

Takes a Polygon object and simplifies the points by running them through a combination of Douglas-Peucker and Radial Distance algorithms. Simplification dramatically reduces the number of points in a polygon while retaining its shape, giving a huge performance boost when processing it and also reducing visual noise.

Tags:

  • generic

Parameters:

name

type

optional

default

description

polygon

Phaser.Geom.Polygon

No

The polygon to be simplified. The polygon will be modified in-place and returned.

tolerance

number

Yes

1

Affects the amount of simplification (in the same metric as the point coordinates).

highestQuality

boolean

Yes

false

Excludes distance-based preprocessing step which leads to highest quality simplification but runs ~10-20 times slower.

Returns: Phaser.Geom.Polygon - The input polygon.

Source: src/geom/polygon/Simplify.js#L160
Since: 3.50.0


Smooth

<static> Smooth(polygon)

Description:

Takes a Polygon object and applies Chaikin's smoothing algorithm on its points.

Tags:

  • generic

Parameters:

name

type

optional

description

polygon

Phaser.Geom.Polygon

No

The polygon to be smoothed. The polygon will be modified in-place and returned.

Returns: Phaser.Geom.Polygon - The input polygon.

Source: src/geom/polygon/Smooth.js#L19
Since: 3.13.0


Translate

<static> Translate(polygon, x, y)

Description:

Tranlates the points of the given Polygon.

Tags:

  • generic

Parameters:

name

type

optional

description

polygon

Phaser.Geom.Polygon

No

The Polygon to modify.

x

number

No

The amount to horizontally translate the points by.

y

number

No

The amount to vertically translate the points by.

Returns: Phaser.Geom.Polygon - The modified Polygon.

Source: src/geom/polygon/Translate.js#L7
Since: 3.50.0


Public Members

area

area: number

Description:

The area of this Polygon.

Source: src/geom/polygon/Polygon.js#L51
Since: 3.0.0


points

points: Array.<Phaser.Geom.Point>

Description:

An array of number pair objects that make up this polygon. I.e. [ {x,y}, {x,y}, {x,y} ]

Source: src/geom/polygon/Polygon.js#L61
Since: 3.0.0


type

type: number

Description:

The geometry constant type of this object: GEOM_CONST.POLYGON. Used for fast type comparisons.

Source: src/geom/polygon/Polygon.js#L40
Since: 3.19.0


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