Fast World.contactMaterials lookup

src/material/ContactMaterial.js

@@ -116,3 +116,20 @@ function ContactMaterial(materialA, materialB, options){
 }
 
 ContactMaterial.idCounter = 0;
+
+/**
+ * Returns unique hash that was generated based on material id's. Usage: World.contactMaterials[hash].
+ * @private
+ * @method getHash
+ */
+ContactMaterial.prototype.getHash = function(){
+    return ContactMaterial.createHash(this.materialA, this.materialB);
+};
+
+ContactMaterial.createHash = function(materialA, materialB){
+	if (materialA.id <= materialB.id) {
+		return materialA.id + '-' + materialB.id;
+	} else {
+		return materialB.id + '-' + materialA.id;
+	}
+};

src/world/World.js

@@ -174,11 +174,11 @@ function World(options){
     this.solveConstraints = true;
 
     /**
-     * The ContactMaterials added to the World.
+     * Hash object containing ContactMaterials added to the World.
      * @property contactMaterials
-     * @type {Array}
+     * @type {Object}
      */
-    this.contactMaterials = [];
+    this.contactMaterials = {};
 
     /**
      * World time.
@@ -400,7 +400,7 @@ World.prototype.addConstraint = function(constraint){
  * @param {ContactMaterial} contactMaterial
  */
 World.prototype.addContactMaterial = function(contactMaterial){
-    this.contactMaterials.push(contactMaterial);
+    this.contactMaterials[contactMaterial.getHash()] = contactMaterial;
 };
 
 /**
@@ -410,7 +410,7 @@ World.prototype.addContactMaterial = function(contactMaterial){
  * @param {ContactMaterial} cm
  */
 World.prototype.removeContactMaterial = function(cm){
-    arrayRemove(this.contactMaterials, cm);
+    delete this.contactMaterials[cm.getHash()];
 };
 
 /**
@@ -419,17 +419,9 @@ World.prototype.removeContactMaterial = function(cm){
  * @param {Material} materialA
  * @param {Material} materialB
  * @return {ContactMaterial} The matching ContactMaterial, or false on fail.
- * @todo Use faster hash map to lookup from material id's
  */
 World.prototype.getContactMaterial = function(materialA,materialB){
-    var cmats = this.contactMaterials;
-    for(var i=0, N=cmats.length; i!==N; i++){
-        var cm = cmats[i];
-        if((cm.materialA === materialA && cm.materialB === materialB) || (cm.materialA === materialB && cm.materialB === materialA)){
-            return cm;
-        }
-    }
-    return false;
+	return this.contactMaterials[ContactMaterial.createHash(materialA, materialB)] || false;
 };
 
 /**
@@ -1166,9 +1158,8 @@ World.prototype.clear = function(){
 
     // Remove all contact materials
     var cms = this.contactMaterials;
-    i = cms.length;
-    while(i--){
-        this.removeContactMaterial(cms[i]);
+    for (var hash in cms) {
+        delete cms[hash];
     }
 };
 
@@ -1234,8 +1225,8 @@ World.prototype.setGlobalStiffness = function(stiffness){
 
     // Set for all contact materials
     var contactMaterials = this.contactMaterials;
-    for(var i=0; i !== contactMaterials.length; i++){
-        var c = contactMaterials[i];
+    for(var hash in contactMaterials){
+        var c = contactMaterials[hash];
         c.stiffness = c.frictionStiffness = stiffness;
     }
 
@@ -1253,8 +1244,9 @@ World.prototype.setGlobalRelaxation = function(relaxation){
     setGlobalEquationParams(this, { relaxation: relaxation });
 
     // Set for all contact materials
-    for(var i=0; i !== this.contactMaterials.length; i++){
-        var c = this.contactMaterials[i];
+	var contactMaterials = this.contactMaterials;
+	for(var hash in contactMaterials){
+		var c = contactMaterials[hash];
         c.relaxation = c.frictionRelaxation = relaxation;
     }
 

test/world/World.js

@@ -140,7 +140,7 @@ exports.clear = function(test){
     test.deepEqual(world.bodies, []);
     test.deepEqual(world.springs, []);
     test.deepEqual(world.constraints, []);
-    test.deepEqual(world.contactMaterials, []);
+    test.deepEqual(world.contactMaterials, {});
 
     test.done();
 };