adding ids in constructors instead of in World

src/constraints/Constraint.js

@@ -25,6 +25,11 @@ function Constraint(bodyA,bodyB){
      * @property {Body} bodyB
      */
     this.bodyB = bodyB;
+
+    /**
+     * @property {Number} id
+     */
+    this.id = Constraint.idCounter++;
 };
 
 /**
@@ -33,3 +38,5 @@ function Constraint(bodyA,bodyB){
 Constraint.prototype.update = function(){
     throw new Error("method update() not implmemented in this Constraint subclass!");
 };
+
+Constraint.idCounter = 0;

src/material/ContactMaterial.js

@@ -16,7 +16,7 @@ function ContactMaterial(m1, m2, friction, restitution){
      * Identifier of this material
      * @property {Number} id
      */
-    this.id = -1;
+    this.id = ContactMaterial.idCounter++;
 
     /**
      * Participating materials
@@ -62,3 +62,4 @@ function ContactMaterial(m1, m2, friction, restitution){
     this.frictionEquationRegularizationTime = 3;
 };
 
+ContactMaterial.idCounter = 0;

src/material/Material.js

@@ -13,6 +13,7 @@ function Material(name){
      * @type {String}
      */
     this.name = name;
-    this.id = -1;
+    this.id = Material.idCounter++;
 };
 
+Material.idCounter = 0;

src/objects/Body.js

@@ -16,6 +16,8 @@ function Body(type){
 
     this.type = type;
 
+    this.id = Body.idCounter++;
+
     /**
      * Reference to the world the body is living in
      * @property world
@@ -82,3 +84,5 @@ Body.STATIC = 2;
  * @type {Number}
  */
 Body.KINEMATIC = 4;
+
+Body.idCounter = 0;

src/world/World.js

@@ -228,7 +228,6 @@ World.prototype.collisionMatrixTick = function(){
  * @todo Adding an array of bodies should be possible. This would save some loops too
  */
 World.prototype.add = function(body){
-	body.id = this.id();
     body.index = this.bodies.length;
     this.bodies.push(body);
     body.world = this;
@@ -251,7 +250,6 @@ World.prototype.add = function(body){
  */
 World.prototype.addConstraint = function(c){
     this.constraints.push(c);
-    c.id = this.id();
 };
 
 /**
@@ -266,15 +264,6 @@ World.prototype.removeConstraint = function(c){
     }
 };
 
-/**
- * Generate a new unique integer identifyer
- * @method id
- * @return {Number}
- */
-World.prototype.id = function(){
-    return this.nextId++;
-};
-
 /**
  * Remove a rigid body from the simulation.
  * @method remove
@@ -294,17 +283,13 @@ World.prototype.remove = function(body){
 };
 
 /**
- * Adds a material to the World. A material can only be added once, it's added more times then nothing will happen.
+ * Adds a material to the World.
  * @method addMaterial
  * @param {Material} m
  * @todo Necessary?
  */
 World.prototype.addMaterial = function(m){
-    if(m.id === -1){
-        var n = this.materials.length;
-        this.materials.push(m);
-        m.id = this.materials.length-1;
-    }
+    this.materials.push(m);
 };
 
 /**
@@ -314,13 +299,8 @@ World.prototype.addMaterial = function(m){
  */
 World.prototype.addContactMaterial = function(cmat) {
 
-    // Add materials if they aren't already added
-    this.addMaterial(cmat.materials[0]);
-    this.addMaterial(cmat.materials[1]);
-
     // Add contact material
     this.contactmaterials.push(cmat);
-    cmat.id = this.contactmaterials.length-1;
 
     // Add current contact material to the material table
     this.contactMaterialTable.set(cmat.materials[0].id,cmat.materials[1].id,cmat);