Attractor behavior attracts bodies to a specific point.

Additional options include:

• pos: The position of the attraction point
• strength: How strong the attraction is (default: 1)
• order: The power of the inverse distance (default: 2 because that is newtonian gravity... inverse square)
• max: The maximum distance in which to apply the attraction (default: Infinity)
• min: The minimum distance above which to apply the attraction (default: very small non-zero)

Detect collisions of bodies.

Publishes collision events to the world as a group of detected collisions per iteration.

The event data will have a .collisions property that is an array of collisions of the form:

{
    bodyA: // the first body
    bodyB: // the second body
    norm: // the normal vector (Vectorish)
    mtv: // the minimum transit vector. (the direction and length needed to extract bodyB from bodyA)
    pos: // the collision point relative to bodyA
    overlap: // the amount bodyA overlaps bodyB
}

Additional options include:

• check: channel to listen to for collision candidates (default: collisions:candidates). set to true to force check every pair of bodies in the world
• channel: channel to publish events to (default: collisions:detected)

Responds to collisions by applying impulses.

Additional options include:

• check: channel to listen to for collisions (default: collisions:detected).
• mtvThreshold: apply partial extraction of bodies if the minimum transit vector is less than this value ( default: 1) this will depend on your simulation characteristic length scale
• bodyExtractDropoff: every body overlap correction (underneith mtvThreshold) will only extract by this fraction (0..1). Helps with stablizing contacts. (default: 0.5)
• forceWakeupAboveOverlapThreshold: force bodies to wake up if the overlap is above mtvThreshold ( default: true )

Constant acceleration behavior.

Basically the "gravity" behavior. Used to give "earth-like gravity" to the world.

Additional options include:

• acc: The acceleration vector (Vectorish). (default: { x: 0, y: 0.0004 })

Used to detect collisions with the boundaries of an AABB.

Additional options include:

• aabb: The Physics.aabb bounds to use as the constraining boundary
• restitution: The restitution of the boundary walls (default: 0.99)
• cof: The coefficient of friction of the boundary walls (default: 1)
• channel: The channel to publish collisions to. (default: 'collisions:detected')

User interaction helper.

Used to get mouse/touch events and add grab interactions.

Additional options include:

• el: The element of the renderer. What you input as the el for the renderer.
• moveThrottle: The min time between move events (default: 10).
• minVel: The minimum velocity clamp Vectorish (default: { x: -5, y: -5 }) to restrict velocity a user can give to a body
• maxVel: The maximum velocity clamp Vectorish (default: { x: 5, y: 5 }) to restrict velocity a user can give to a body

The behavior also triggers the following events on the world:

// a body has been grabbed
world.on('interact:grab', function( data ){
    data.x; // the x coord
    data.y; // the y coord
    data.body; // the body that was grabbed
});
// no body was grabbed, but the renderer area was clicked, or touched
world.on('interact:poke', function( data ){
    data.x; // the x coord
    data.y; // the y coord
});
// when a mouse or pointer moves
world.on('interact:move', function( data ){
    data.x; // the x coord
    data.y; // the y coord
    data.body; // the grabbed body that was moved (if applicable)
});
// when the viewport is released (mouseup, touchend)
world.on('interact:release', function( data ){
    data.x; // the x coord
    data.y; // the y coord
    data.body; // the body that was grabbed (if applicable)
});

The behavior also sets body.isGrabbed = true for any grabbed bodies while they are grabbed.

Newtonian attraction between bodies (inverse square law).

Additional options include:

• strength: The strength of the interaction between bodies. (default: 1)
• max: The maximum distance between bodies at which to apply the behavior. (default: false... infinite)
• min: The minimum distance between bodies at which to apply the behavior. (default: false... autocalculate)

Sweep and Prune implementation for broad phase collision detection.

This massively improves the speed of collision detection. It's set up to always be used with BodyCollisionDetection, and BodyImpulseResponse.

Additional options include:

• channel: The channel to publish collision candidates to. (default: collisions:candidates)

Verlet constraints manager.

Handles distance constraints, and angle constraints

Additional options include:

• iterations: The number of iterations to take to relax the constraints. (default: 2)

The circle body has a circular shape.

Additional options include:

• radius: the radius

Example:

var round = Physics.body('circle', {
    x: 30,
    y: 20,
    radius: 5
});

Not a body in itself. It's a container to group other bodies. The position of the body is the center of mass. It must have at least one child before being added to the world.

Additional config options:

• children: Array of Body objects.

Example:

var thing = Physics.body('compound', {
    // place the center of mass at (300, 200)
    x: 300,
    y: 200,
    // the center of mass is automatically calculated and used to position the shape
    children: [
        body1,
        body2,
        // ...
    ]
});

Body for convex polygons. The position of the body is the centroid of the polygon.

Additional config options:

• vertices: Array of Vectorish objects representing the polygon vertices in clockwise (or counterclockwise) order.

Example:

var pentagon = Physics.body('convex-polygon', {
    // place the centroid of the polygon at (300, 200)
    x: 300,
    y: 200,
    // the centroid is automatically calculated and used to position the shape
    vertices: [
        { x: 0, y: -30 },
        { x: -29, y: -9 },
        { x: -18, y: 24 },
        { x: 18, y: 24 },
        { x: 29, y: -9 }
    ]
});

The point body represents a point.

Body for rectangles. The position of the body is the centroid of the rectangle.

Additional config options:

• width: The width
• height: The height

Example:

var rect = Physics.body('rectangle', {
    // place the centroid of the rectangle at (300, 200)
    x: 300,
    y: 200,
    width: 30,
    height: 40
});

The circle geometry has a circular shape.

Additional options include:

• radius: the radius

Example:

var round = Physics.body('circle', {
    x: 30,
    y: 20,
    radius: 5
});

Geometry for compound shapes.

Example:

var thing = Physics.geometry('compound');
thing.addChild( child, pos, rotation );

Geometry for convex polygons.

Additional config options:

• vertices: Array of Vectorish objects representing the polygon vertices in clockwise (or counterclockwise) order.

Example:

var pentagon = Physics.geometry('convex-polygon', {
    // the centroid is automatically calculated and used to position the shape
    vertices: [
        { x: 0, y: -30 },
        { x: -29, y: -9 },
        { x: -18, y: 24 },
        { x: 18, y: 24 },
        { x: 29, y: -9 }
    ]
});

The point geometry represents a point.

Geometry for rectangles.

Additional config options:

• width: The width
• height: The height

Example:

var rectGeo = Physics.geometry('rectangle', {
    width: 30,
    height: 40
});

The improved euler integrator.

The velocity-verlet integrator.

The verlet integrator.

Renderer that uses HTMLCanvas to render the world bodies.

Additional config options:

• metaEl: HTMLElement to write meta information like FPS and IPF into. (default: autogenerated)
• offset: Offset the shapes by this amount. (default: { x: 0, y: 0 })
• styles: Styles to use to draw the shapes. (see below)

The styles property should contain default styles for each shape you want to draw.

Example:

styles: {

   'circle' : {
       strokeStyle: '#542437',
       lineWidth: 1,
       fillStyle: '#542437',
       angleIndicator: 'white'
   },

   'convex-polygon' : {
       strokeStyle: '#542437',
       lineWidth: 1,
       fillStyle: '#542437',
       angleIndicator: 'white'
   }
}