feeles-ide/samples/matterjs/plugins/attractorsPlugin.js

The hackable and serializable IDE to make learning material

// NOTE: this plugin will be moved to its own repo

import {
	Plugin,
	Composite,
	Common,
	Body,
} from 'matter';


const MatterAttractors = {
	name: 'matter-attractors',

	version: '0.1.0',

	for: 'matter-js@^0.10.0',

	install: function(base) {
		base.after('Body.create', function() {
			MatterAttractors.Body.init(this);
		});

		base.after('Engine.update', function() {
			MatterAttractors.Engine.update(this);
		});
	},

	Body: {
		init: function(body) {
			body.attractors = body.attractors || [];
		}
	},

	Engine: {
		update: function(engine) {
			var world = engine.world,
				bodies = Composite.allBodies(world);

			for (var i = 0; i < bodies.length; i += 1) {
				var bodyA = bodies[i],
					attractors = bodyA.attractors;

				if (attractors && attractors.length > 0) {
					for (var j = i + 1; j < bodies.length; j += 1) {
						var bodyB = bodies[j];

						for (var k = 0; k < attractors.length; k += 1) {
							var attractor = attractors[k],
								forceVector = attractor;

							if (Common.isFunction(attractor)) {
								forceVector = attractor(bodyA, bodyB);
							}

							if (forceVector) {
								Body.applyForce(bodyB, bodyB.position, forceVector);
							}
						}
					}
				}
			}
		}
	}
};

Plugin.register(MatterAttractors);

window.MatterAttractors = MatterAttractors;