verlet-point

This is a point utility for verlet physics systems in 2D/3D.

var Point = require('verlet-point')

var p = Point({
    position: [25, 25]
})

p.addForce([15, 15])

Whereas with bare objects, it might look like this:

var p = {
    position: [25, 25],
    previous: [25, 25],
    acceleration: [0, 0],
    mass: 1     //defaults to 1.0
    radius: 25  //defaults to 0.0
}

//add force by modifying previous position
p.previous[0] -= 15
p.previous[1] -= 15

Some other utility functions might be added to the Point prototype at a later time. PRs welcome.

By default, assumes 2D and points with [x, y]. You can require an explicit dimension like so:

var Point2D = require('verlet-point/2d') //points [x, y]
var Point3D = require('verlet-point/3d') //points [x, y, z]

Usage

p = Point([opt])

Creates a new point with an optional position and other parameters. If position is specified and previous is not, then both will be set to the position value. This allows you to easily place points without any initial forces. Options:

• position the position vector, defaults to zero.
• previous the previous vector, useful for creating forces. If not specified, this will default to position value.
• acceleration the acceleration vector of the point, defaults to zero
• mass the mass of this point, defaults to 1.0. A mass of zero is considered "unmovable."
• radius the radius of this point, only useful for collision testing. Defaults to zero.

p.place(pos)

This is a utility to "place" the point in space without creating any forces. This sets position and previous to the given pos. Returns this for chaining.

p.addForce(force)

Adds a force to the point by subtracting force from previous. Returns this for chaining.

p.position

p.previous

p.acceleration

p.mass

Public members for this point.

License

MIT, see LICENSE.md for details.