Nodes Per Minute

npm

circle2

1.1.1 • Public • Published

install

npm install circle2

use

Where origin adheres to the following form:

• [0, 1]
• { x: 0, y: 1}

Note: the arguments to the Circle function are optional. If none are passed circle.position will be 0, 0 and circle.radius will be 1

You can also pass in a 3 points and have the circle computed from them:

or an 3-item array of Vec2

Note: changing the passed Vec2s will change the circle

Instance Methods

Get/Set the radius of the circle

containsPoint(point)

Where point looks like one of the following:

• [0, 1]
• { x: 0, y: 1 }
• new Vec2(0, 1)

This function will return true if the passed point is inside or right on the boundary of the circle.

contains(thing)

Where thing meets the following criteria:

• has .position and .radius() - circle
• has a function .points() or array .points - polygon
• has .x1, .y1, .x2, and .y2 - rectangle
• has .x, .y, .w, and .h - rectangle
• has .x, .y, .width, and .height - rectangle

This method will return true if the passed thing is completely inside, and false otherwise.

Note: if the points of thing are on the circumference of the circle, this method will return true

change(fn)

This is a method that you want to have called any time the circle changes. Either in radius or position

ignore([fn])

Takes an optional fn parameter which if passed will remove the specified listener.

If no fn is passed, all the listeners will be removed.

notify()

Force listeners to be called.

area()

Returns the area PI * r^2

circumference()

Returns the circumference PI * r*2

intersectCircle(circle)

Performs an intersection between this circle and the incoming. Results are as follows:

• false - no intersection or one circle is contained in the other
• [] - same circles
• [Vec2] - single intersection
• [Vec2, Vec2] - two intersection points

toSegments([segments])

Convert this circle into a series of points representing the outline of this circle

Keywords

Install

npm i circle2

Repository

github.com/tmpvar/circle2