# Class: Ellipse

## Phaser.Curves. Ellipse

An Elliptical Curve derived from the Base Curve class.

See https://en.wikipedia.org/wiki/Elliptic_curve for more details.

#### new Ellipse( [x] [, y] [, xRadius] [, yRadius] [, startAngle] [, endAngle] [, clockwise] [, rotation])

##### Parameters:
Name Type Argument Default Description
`x` number | Phaser.Types.Curves.EllipseCurveConfig <optional>
0

The x coordinate of the ellipse, or an Ellipse Curve configuration object.

`y` number <optional>
0

The y coordinate of the ellipse.

`xRadius` number <optional>
0

`yRadius` number <optional>
0

`startAngle` integer <optional>
0

The start angle of the ellipse, in degrees.

`endAngle` integer <optional>
360

The end angle of the ellipse, in degrees.

`clockwise` boolean <optional>
false

Whether the ellipse angles are given as clockwise (`true`) or counter-clockwise (`false`).

`rotation` integer <optional>
0

The rotation of the ellipse, in degrees.

Since: 3.0.0
Source: src/curves/EllipseCurve.js (Line 16)

### Members

#### active :boolean

For a curve on a Path, `false` means the Path will ignore this curve.

##### Type:
• boolean
Since: 3.0.0
Inherited From:
Default Value:
• true
Source: src/curves/Curve.js (Line 80)

#### angle :number

The rotation of the ellipse, relative to the center, in degrees.

##### Type:
• number
Since: 3.14.0
Source: src/curves/EllipseCurve.js (Line 536)

#### arcLengthDivisions :integer

The quantity of arc length divisions within the curve.

##### Type:
• integer
Since: 3.0.0
Inherited From:
Default Value:
• 100
Source: src/curves/Curve.js (Line 50)

#### cacheArcLengths :Array.<number>

An array of cached arc length values.

##### Type:
• Array.<number>
Since: 3.0.0
Inherited From:
Default Value:
• []
Source: src/curves/Curve.js (Line 60)

#### clockwise :boolean

`true` if the ellipse rotation is clockwise or `false` if anti-clockwise.

##### Type:
• boolean
Since: 3.0.0
Source: src/curves/EllipseCurve.js (Line 515)

#### defaultDivisions :integer

The default number of divisions within the curve.

##### Type:
• integer
Since: 3.0.0
Inherited From:
Default Value:
• 5
Source: src/curves/Curve.js (Line 40)

#### endAngle :number

The end angle of the ellipse in degrees.

##### Type:
• number
Since: 3.0.0
Source: src/curves/EllipseCurve.js (Line 494)

#### needsUpdate :boolean

Does the data of this curve need updating?

##### Type:
• boolean
Since: 3.0.0
Inherited From:
Default Value:
• true
Source: src/curves/Curve.js (Line 70)

#### p0 :Phaser.Math.Vector2

The center point of the ellipse. Used for calculating rotation.

##### Type:
Since: 3.0.0
Source: src/curves/EllipseCurve.js (Line 71)

#### rotation :number

The rotation of the ellipse, relative to the center, in radians.

##### Type:
• number
Since: 3.0.0
Source: src/curves/EllipseCurve.js (Line 557)

#### startAngle :number

The start angle of the ellipse in degrees.

##### Type:
• number
Since: 3.0.0
Source: src/curves/EllipseCurve.js (Line 473)

#### type :string

String based identifier for the type of curve.

##### Type:
• string
Since: 3.0.0
Inherited From:
Source: src/curves/Curve.js (Line 31)

#### x :number

The x coordinate of the center of the ellipse.

##### Type:
• number
Since: 3.0.0
Source: src/curves/EllipseCurve.js (Line 389)

The horizontal radius of the ellipse.

##### Type:
• number
Since: 3.0.0
Source: src/curves/EllipseCurve.js (Line 431)

#### y :number

The y coordinate of the center of the ellipse.

##### Type:
• number
Since: 3.0.0
Source: src/curves/EllipseCurve.js (Line 410)

The vertical radius of the ellipse.

##### Type:
• number
Since: 3.0.0
Source: src/curves/EllipseCurve.js (Line 452)

### Methods

#### <static> fromJSON(data)

Creates a curve from the provided Ellipse Curve Configuration object.

##### Parameters:
Name Type Description
`data` Phaser.Types.Curves.JSONEllipseCurve

The JSON object containing this curve data.

Since: 3.0.0
Source: src/curves/EllipseCurve.js (Line 603)
##### Returns:

The ellipse curve constructed from the configuration object.

Type
Phaser.Curves.Ellipse

#### draw(graphics [, pointsTotal])

Draws this curve on the given Graphics object.

The curve is drawn using `Graphics.strokePoints` so will be drawn at whatever the present Graphics stroke color is. The Graphics object is not cleared before the draw, so the curve will appear on-top of anything else already rendered to it.

##### Parameters:
Name Type Argument Default Description
`graphics` Phaser.GameObjects.Graphics

The Graphics instance onto which this curve will be drawn.

`pointsTotal` integer <optional>
32

The resolution of the curve. The higher the value the smoother it will render, at the cost of rendering performance.

Since: 3.0.0
Inherited From:
Source: src/curves/Curve.js (Line 111)
##### Returns:

The Graphics object to which the curve was drawn.

Type
Phaser.GameObjects.Graphics

#### getBounds( [out] [, accuracy])

Returns a Rectangle where the position and dimensions match the bounds of this Curve.

You can control the accuracy of the bounds. The value given is used to work out how many points to plot across the curve. Higher values are more accurate at the cost of calculation speed.

##### Parameters:
Name Type Argument Default Description
`out` Phaser.Geom.Rectangle <optional>

The Rectangle to store the bounds in. If falsey a new object will be created.

`accuracy` integer <optional>
16

The accuracy of the bounds calculations.

Since: 3.0.0
Inherited From:
Source: src/curves/Curve.js (Line 135)
##### Returns:

A Rectangle object holding the bounds of this curve. If `out` was given it will be this object.

Type
Phaser.Geom.Rectangle

#### getDistancePoints(distance)

Returns an array of points, spaced out X distance pixels apart. The smaller the distance, the larger the array will be.

##### Parameters:
Name Type Description
`distance` integer

The distance, in pixels, between each point along the curve.

Since: 3.0.0
Inherited From:
Source: src/curves/Curve.js (Line 169)
##### Returns:

An Array of Point objects.

Type
Array.<Phaser.Geom.Point>

#### getEndPoint( [out])

Get a point at the end of the curve.

##### Parameters:
Name Type Argument Description
`out` Phaser.Math.Vector2 <optional>

Optional Vector object to store the result in.

Since: 3.0.0
Inherited From:
Source: src/curves/Curve.js (Line 189)
##### Returns:

Vector2 containing the coordinates of the curves end point.

Type
Phaser.Math.Vector2

#### getLength()

Get total curve arc length

Since: 3.0.0
Inherited From:
Source: src/curves/Curve.js (Line 206)
##### Returns:

The total length of the curve.

Type
number

#### getLengths( [divisions])

Get a list of cumulative segment lengths.

These lengths are

• [0] 0
• [1] The first segment
• [2] The first and second segment
• ...
• [divisions] All segments
##### Parameters:
Name Type Argument Description
`divisions` integer <optional>

The number of divisions or segments.

Since: 3.0.0
Inherited From:
Source: src/curves/Curve.js (Line 222)
##### Returns:

An array of cumulative lengths.

Type
Array.<number>

#### getPoint(t [, out])

Get point at relative position in curve according to length.

##### Parameters:
Name Type Argument Description
`t` number

The position along the curve to return. Where 0 is the start and 1 is the end.

`out` Phaser.Math.Vector2 <optional>

A Vector2 object to store the result in. If not given will be created.

Since: 3.0.0
Source: src/curves/EllipseCurve.js (Line 177)
##### Returns:

The coordinates of the point on the curve. If an `out` object was given this will be returned.

Type
Phaser.Math.Vector2

#### getPointAt(u [, out])

Get a point at a relative position on the curve, by arc length.

##### Parameters:
Name Type Argument Description
`u` number

The relative position, [0..1].

`out` Phaser.Math.Vector2 <optional>

A point to store the result in.

Since: 3.0.0
Inherited From:
Source: src/curves/Curve.js (Line 278)
##### Returns:

The point.

Type
Phaser.Math.Vector2

#### getPoints( [divisions] [, stepRate] [, out])

Get a sequence of evenly spaced points from the curve.

You can pass `divisions`, `stepRate`, or neither.

The number of divisions will be

1. `divisions`, if `divisions` > 0; or
2. `this.getLength / stepRate`, if `stepRate` > 0; or
3. `this.defaultDivisions`

`1 + divisions` points will be returned.

##### Parameters:
Name Type Argument Description
`divisions` integer <optional>

The number of divisions to make.

`stepRate` number <optional>

The curve distance between points, implying `divisions`.

`out` array | Array.<Phaser.Math.Vector2> <optional>

An optional array to store the points in.

Since: 3.0.0
Inherited From:
Source: src/curves/Curve.js (Line 300)
##### Returns:

An array of Points from the curve.

Type
array | Array.<Phaser.Math.Vector2>

#### getRandomPoint( [out])

Get a random point from the curve.

##### Parameters:
Name Type Argument Description
`out` Phaser.Math.Vector2 <optional>

A point object to store the result in.

Since: 3.0.0
Inherited From:
Source: src/curves/Curve.js (Line 349)
##### Returns:

The point.

Type
Phaser.Math.Vector2

#### getResolution(divisions)

Get the resolution of the curve.

##### Parameters:
Name Type Description
`divisions` number

Optional divisions value.

Since: 3.0.0
Source: src/curves/EllipseCurve.js (Line 162)
##### Returns:

The curve resolution.

Type
number

#### getSpacedPoints( [divisions] [, stepRate] [, out])

Get a sequence of equally spaced points (by arc distance) from the curve.

`1 + divisions` points will be returned.

##### Parameters:
Name Type Argument Default Description
`divisions` integer <optional>
this.defaultDivisions

The number of divisions to make.

`stepRate` number <optional>

Step between points. Used to calculate the number of points to return when divisions is falsy. Ignored if divisions is positive.

`out` array | Array.<Phaser.Math.Vector2> <optional>

An optional array to store the points in.

Since: 3.0.0
Inherited From:
Source: src/curves/Curve.js (Line 370)
##### Returns:

An array of points.

Type
Array.<Phaser.Math.Vector2>

#### getStartPoint( [out])

Gets the starting point on the curve.

##### Parameters:
Name Type Argument Description
`out` Phaser.Math.Vector2 <optional>

A Vector2 object to store the result in. If not given will be created.

Since: 3.0.0
Overrides:
Source: src/curves/EllipseCurve.js (Line 143)
##### Returns:

The coordinates of the point on the curve. If an `out` object was given this will be returned.

Type
Phaser.Math.Vector2

#### getTangent(t [, out])

Get a unit vector tangent at a relative position on the curve. In case any sub curve does not implement its tangent derivation, 2 points a small delta apart will be used to find its gradient which seems to give a reasonable approximation

##### Parameters:
Name Type Argument Description
`t` number

The relative position on the curve, [0..1].

`out` Phaser.Math.Vector2 <optional>

A vector to store the result in.

Since: 3.0.0
Inherited From:
Source: src/curves/Curve.js (Line 430)
##### Returns:

Vector approximating the tangent line at the point t (delta +/- 0.0001)

Type
Phaser.Math.Vector2

#### getTangentAt(u [, out])

Get a unit vector tangent at a relative position on the curve, by arc length.

##### Parameters:
Name Type Argument Description
`u` number

The relative position on the curve, [0..1].

`out` Phaser.Math.Vector2 <optional>

A vector to store the result in.

Since: 3.0.0
Inherited From:
Source: src/curves/Curve.js (Line 472)
##### Returns:

The tangent vector.

Type
Phaser.Math.Vector2

#### getTFromDistance(distance [, divisions])

Given a distance in pixels, get a t to find p.

##### Parameters:
Name Type Argument Description
`distance` integer

The distance, in pixels.

`divisions` integer <optional>

Optional amount of divisions.

Since: 3.0.0
Inherited From:
Source: src/curves/Curve.js (Line 492)

The distance.

Type
number

#### getUtoTmapping(u, distance [, divisions])

Given u ( 0 .. 1 ), get a t to find p. This gives you points which are equidistant.

##### Parameters:
Name Type Argument Description
`u` number

A float between 0 and 1.

`distance` integer

The distance, in pixels.

`divisions` integer <optional>

Optional amount of divisions.

Since: 3.0.0
Inherited From:
Source: src/curves/Curve.js (Line 513)
##### Returns:

The equidistant value.

Type
number

#### setClockwise(value)

Sets if this curve extends clockwise or anti-clockwise.

##### Parameters:
Name Type Description
`value` boolean

The clockwise state of this curve.

Since: 3.0.0
Source: src/curves/EllipseCurve.js (Line 355)
##### Returns:

This curve object.

Type
Phaser.Curves.Ellipse

#### setEndAngle(value)

Sets the end angle of this curve.

##### Parameters:
Name Type Description
`value` number

The end angle of this curve, in radians.

Since: 3.0.0
Source: src/curves/EllipseCurve.js (Line 338)
##### Returns:

This curve object.

Type
Phaser.Curves.Ellipse

#### setHeight(value)

Sets the height of this curve.

##### Parameters:
Name Type Description
`value` number

The height of this curve.

Since: 3.0.0
Source: src/curves/EllipseCurve.js (Line 304)
##### Returns:

This curve object.

Type
Phaser.Curves.Ellipse

#### setRotation(value)

Sets the rotation of this curve.

##### Parameters:
Name Type Description
`value` number

The rotation of this curve, in radians.

Since: 3.0.0
Source: src/curves/EllipseCurve.js (Line 372)
##### Returns:

This curve object.

Type
Phaser.Curves.Ellipse

#### setStartAngle(value)

Sets the start angle of this curve.

##### Parameters:
Name Type Description
`value` number

The start angle of this curve, in radians.

Since: 3.0.0
Source: src/curves/EllipseCurve.js (Line 321)
##### Returns:

This curve object.

Type
Phaser.Curves.Ellipse

#### setWidth(value)

Sets the width of this curve.

##### Parameters:
Name Type Description
`value` number

The width of this curve.

Since: 3.0.0
Source: src/curves/EllipseCurve.js (Line 287)
##### Returns:

This curve object.

Type
Phaser.Curves.Ellipse

Sets the horizontal radius of this curve.

##### Parameters:
Name Type Description
`value` number

The horizontal radius of this curve.

Since: 3.0.0
Source: src/curves/EllipseCurve.js (Line 253)
##### Returns:

This curve object.

Type
Phaser.Curves.Ellipse

Sets the vertical radius of this curve.

##### Parameters:
Name Type Description
`value` number

The vertical radius of this curve.

Since: 3.0.0
Source: src/curves/EllipseCurve.js (Line 270)
##### Returns:

This curve object.

Type
Phaser.Curves.Ellipse

#### toJSON()

JSON serialization of the curve.

Since: 3.0.0
Source: src/curves/EllipseCurve.js (Line 578)
##### Returns:

The JSON object containing this curve data.

Type
Phaser.Types.Curves.JSONEllipseCurve

#### updateArcLengths()

Calculate and cache the arc lengths.

Since: 3.0.0
Inherited From:
Source: src/curves/Curve.js (Line 594)
See:
• Phaser.Curves.Curve#getLengths()