added plugins matter-attractors, matter-gravity, matter-world-wrap, r…

…emoved test plugins

examples/attractorsPlugin.js

@@ -0,0 +1,67 @@
+(function() {
+
+    var Body = Matter.Body,
+        Common = Matter.Common,
+        Composite = Matter.Composite;
+
+    var MatterAttractors = {
+        name: 'matter-attractors',
+
+        version: '0.1.0',
+
+        for: 'matter-js@^0.10.0',
+
+        install: function(base) {
+            base.Body.create = Common.chain(
+                Matter.Body.create,
+                MatterAttractors.init
+            );
+
+            base.Engine.update = Common.chain(
+                Matter.Engine.update,
+                MatterAttractors.update
+            );
+        },
+
+        init: function(body) {
+            body = this || body;
+            body.attractors = body.attractors || [];
+        },
+
+        update: function(engine) {
+            engine = this || 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);
+                            }
+                        }
+                    }
+                }
+            }
+        }
+    };
+
+    Matter.Plugin.register(MatterAttractors);
+
+    window.MatterAttractors = MatterAttractors;
+
+})();

examples/gravityPlugin.js

@@ -0,0 +1,49 @@
+(function() {
+
+    var Body = Matter.Body,
+        Common = Matter.Common,
+        Vector = Matter.Vector;
+
+    var MatterGravity = {
+        name: 'matter-gravity',
+
+        version: '0.1.0',
+
+        for: 'matter-js@^0.10.0',
+
+        uses: [
+            'matter-attractors@^0.1.0'
+        ],
+
+        install: function(base) {
+            base.Body.create = Common.chain(
+                Matter.Body.create,
+                MatterGravity.addAttractor
+            );
+        },
+
+        addAttractor: function(body) {
+            body = this || body;
+
+            if (body.gravity) {
+                body.attractors.push(MatterGravity.applyForce);
+            }
+        },
+
+        applyForce: function(bodyA, bodyB) {
+            var bToA = Vector.sub(bodyB.position, bodyA.position),
+                distanceSq = Vector.magnitudeSquared(bToA) || 0.0001,
+                normal = Vector.normalise(bToA),
+                magnitude = -bodyA.gravity * (bodyA.mass * bodyB.mass / distanceSq),
+                force = Vector.mult(normal, magnitude);
+
+            Body.applyForce(bodyA, bodyA.position, Vector.neg(force));
+            Body.applyForce(bodyB, bodyB.position, force);
+        }
+    };
+
+    Matter.Plugin.register(MatterGravity);
+
+    window.MatterGravity = MatterGravity;
+
+})();

examples/worldWrapPlugin.js

@@ -0,0 +1,58 @@
+(function() {
+
+    var Body = Matter.Body,
+        Common = Matter.Common,
+        Composite = Matter.Composite;
+
+    var MatterWorldWrap = {
+        name: 'matter-world-wrap',
+
+        version: '0.1.0',
+
+        for: 'matter-js@^0.10.0',
+
+        install: function(base) {
+            base.Engine.update = Common.chain(
+                Matter.Engine.update,
+                MatterWorldWrap.update
+            );
+        },
+
+        update: function(engine) {
+            engine = this || engine;
+
+            var world = engine.world,
+                bodies = Composite.allBodies(world);
+
+            for (var i = 0; i < bodies.length; i += 1) {
+                var body = bodies[i],
+                    x = null,
+                    y = null;
+
+                if (body.bounds.min.x > world.bounds.max.x) {
+                    x = world.bounds.min.x - (body.bounds.max.x - body.position.x);
+                } else if (body.bounds.max.x < world.bounds.min.x) {
+                    x = world.bounds.max.x - (body.bounds.min.x - body.position.x);
+                }
+
+                if (body.bounds.min.y > world.bounds.max.y) {
+                    y = world.bounds.min.y - (body.bounds.max.y - body.position.y);
+                } else if (body.bounds.max.y < world.bounds.min.y) {
+                    y = world.bounds.max.y - (body.bounds.min.y - body.position.y);
+                }
+
+                if (x !== null || y !== null) {
+                    Body.setPosition(body, {
+                        x: x || body.position.x,
+                        y: y || body.position.y
+                    });
+                }
+            }
+        }
+    };
+
+    Matter.Plugin.register(MatterWorldWrap);
+
+    window.MatterWorldWrap = MatterWorldWrap;
+
+})();