Algorithm optimization of Pair methods create and update

src/collision/Contact.js

@@ -1,38 +0,0 @@
-/**
-* The `Matter.Contact` module contains methods for creating and manipulating collision contacts.
-*
-* @class Contact
-*/
-
-var Contact = {};
-
-module.exports = Contact;
-
-(function() {
-
-    /**
-     * Creates a new contact.
-     * @method create
-     * @param {vertex} vertex
-     * @return {contact} A new contact
-     */
-    Contact.create = function(vertex) {
-        return {
-            id: Contact.id(vertex),
-            vertex: vertex,
-            normalImpulse: 0,
-            tangentImpulse: 0
-        };
-    };
-    
-    /**
-     * Generates a contact id.
-     * @method id
-     * @param {vertex} vertex
-     * @return {string} Unique contactID
-     */
-    Contact.id = function(vertex) {
-        return vertex.body.id + '_' + vertex.index;
-    };
-
-})();

src/collision/Pair.js

@@ -8,8 +8,6 @@ var Pair = {};
 
 module.exports = Pair;
 
-var Contact = require('./Contact');
-
 (function() {
     
     /**
@@ -21,26 +19,24 @@ var Contact = require('./Contact');
      */
     Pair.create = function(collision, timestamp) {
         var bodyA = collision.bodyA,
-            bodyB = collision.bodyB,
+            bodyB = collision.bodyB;
-            parentA = collision.parentA,
-            parentB = collision.parentB;
 
         var pair = {
             id: Pair.id(bodyA, bodyB),
             bodyA: bodyA,
             bodyB: bodyB,
-            contacts: {},
             activeContacts: [],
             separation: 0,
             isActive: true,
             isSensor: bodyA.isSensor || bodyB.isSensor,
             timeCreated: timestamp,
             timeUpdated: timestamp,
-            inverseMass: parentA.inverseMass + parentB.inverseMass,
+            collision: null,
-            friction: Math.min(parentA.friction, parentB.friction),
+            inverseMass: 0,
-            frictionStatic: Math.max(parentA.frictionStatic, parentB.frictionStatic),
+            friction: 0,
-            restitution: Math.max(parentA.restitution, parentB.restitution),
+            frictionStatic: 0,
-            slop: Math.max(parentA.slop, parentB.slop)
+            restitution: 0,
+            slop: 0
         };
 
         Pair.update(pair, collision, timestamp);
@@ -56,31 +52,29 @@ var Contact = require('./Contact');
      * @param {number} timestamp
      */
     Pair.update = function(pair, collision, timestamp) {
-        var contacts = pair.contacts,
-            supports = collision.supports,
-            activeContacts = pair.activeContacts,
-            parentA = collision.parentA,
-            parentB = collision.parentB;
-        
         pair.collision = collision;
-        pair.inverseMass = parentA.inverseMass + parentB.inverseMass;
-        pair.friction = Math.min(parentA.friction, parentB.friction);
-        pair.frictionStatic = Math.max(parentA.frictionStatic, parentB.frictionStatic);
-        pair.restitution = Math.max(parentA.restitution, parentB.restitution);
-        pair.slop = Math.max(parentA.slop, parentB.slop);
-        activeContacts.length = 0;
-        
-        if (collision.collided) {
-            for (var i = 0; i < supports.length; i++) {
-                var support = supports[i],
-                    contactId = Contact.id(support),
-                    contact = contacts[contactId];
 
-                if (contact) {
+        if (collision.collided) {
-                    activeContacts.push(contact);
+            var supports = collision.supports,
-                } else {
+                activeContacts = pair.activeContacts;
-                    activeContacts.push(contacts[contactId] = Contact.create(support));
+                parentA = collision.parentA,
-                }
+                parentB = collision.parentB;
+
+            pair.inverseMass = parentA.inverseMass + parentB.inverseMass;
+            pair.friction = Math.min(parentA.friction, parentB.friction);
+            pair.frictionStatic = Math.max(parentA.frictionStatic, parentB.frictionStatic);
+            pair.restitution = Math.max(parentA.restitution, parentB.restitution);
+            pair.slop = Math.max(parentA.slop, parentB.slop);
+
+            for (var i = 0; i < supports.length; i++) {
+                activeContacts[i] = supports[i].contact;
+            }
+
+            // Optimizing out resizing of the array
+            // Most likely unnecessary
+            var supportCount = supports.length;
+            if (supportCount < activeContacts.length) {
+              activeContacts.length = supportCount;
             }
 
             pair.separation = collision.depth;
@@ -123,4 +117,4 @@ var Contact = require('./Contact');
         }
     };
 
-})();
+})();

src/geometry/Vertices.js

@@ -44,9 +44,16 @@ var Common = require('../core/Common');
                     y: point.y,
                     index: i,
                     body: body,
-                    isInternal: false
+                    isInternal: false,
+                    contact: null
                 };
 
+            vertex.contact = {
+                vertex: vertex,
+                normalImpulse: 0,
+                tangentImpulse: 0
+            };
+
             vertices.push(vertex);
         }
 
@@ -443,4 +450,4 @@ var Common = require('../core/Common');
         return upper.concat(lower);
     };
 
-})();
+})();

src/module/main.js

@@ -4,7 +4,6 @@ Matter.Body = require('../body/Body');
 Matter.Composite = require('../body/Composite');
 Matter.World = require('../body/World');
 
-Matter.Contact = require('../collision/Contact');
 Matter.Detector = require('../collision/Detector');
 Matter.Grid = require('../collision/Grid');
 Matter.Pairs = require('../collision/Pairs');