Allow removing spring joing

src/Physics/Plugins/babylon.cannonJSPlugin.ts

@@ -205,14 +205,20 @@
             if (impostorJoint.joint.type !== PhysicsJoint.SpringJoint) {
                 this.world.addConstraint(constraint);
             } else {
-                impostorJoint.mainImpostor.registerAfterPhysicsStep(function () {
+                (<SpringJointData>impostorJoint.joint.jointData).forceApplicationCallback = (<SpringJointData>impostorJoint.joint.jointData).forceApplicationCallback || function () {
                     constraint.applyForce();
-                });
+                };
+                impostorJoint.mainImpostor.registerAfterPhysicsStep((<SpringJointData>impostorJoint.joint.jointData).forceApplicationCallback);
             }
         }
 
         public removeJoint(impostorJoint: PhysicsImpostorJoint) {
-            this.world.removeConstraint(impostorJoint.joint.physicsJoint);
+            if (impostorJoint.joint.type !== PhysicsJoint.SpringJoint) {
+                this.world.removeConstraint(impostorJoint.joint.physicsJoint);
+            } else {
+                impostorJoint.mainImpostor.unregisterAfterPhysicsStep((<SpringJointData>impostorJoint.joint.jointData).forceApplicationCallback);
+            }
+
         }
 
         private _addMaterial(name: string, friction: number, restitution: number) {

src/Physics/babylon.physicsJoint.ts

@@ -40,13 +40,13 @@ module BABYLON {
         public set physicsPlugin(physicsPlugin: IPhysicsEnginePlugin) {
             this._physicsPlugin = physicsPlugin;
         }
-        
+
         /**
          * Execute a function that is physics-plugin specific.
          * @param {Function} func the function that will be executed. 
          *                        It accepts two parameters: the physics world and the physics joint.
          */
-        public executeNativeFunction(func : (world: any, physicsJoint:any) => void) {
+        public executeNativeFunction(func: (world: any, physicsJoint: any) => void) {
             func(this._physicsPlugin.world, this._physicsJoint)
         }
 
@@ -87,13 +87,13 @@ module BABYLON {
             this._physicsPlugin.updateDistanceJoint(this, maxDistance, minDistance);
         }
     }
-    
+
     export class MotorEnabledJoint extends PhysicsJoint implements IMotorEnabledJoint {
-        
-        constructor(type: number, jointData:PhysicsJointData) {
+
+        constructor(type: number, jointData: PhysicsJointData) {
             super(type, jointData);
         }
-        
+
         /**
          * Set the motor values.
          * Attention, this function is plugin specific. Engines won't react 100% the same.
@@ -103,7 +103,7 @@ module BABYLON {
         public setMotor(force?: number, maxForce?: number) {
             this._physicsPlugin.setMotor(this, force || 0, maxForce);
         }
-        
+
         /**
          * Set the motor's limits.
          * Attention, this function is plugin specific. Engines won't react 100% the same.
@@ -117,11 +117,11 @@ module BABYLON {
      * This class represents a single hinge physics joint
      */
     export class HingeJoint extends MotorEnabledJoint {
-        
-        constructor(jointData:PhysicsJointData) {
+
+        constructor(jointData: PhysicsJointData) {
             super(PhysicsJoint.HingeJoint, jointData);
         }
-        
+
         /**
          * Set the motor values.
          * Attention, this function is plugin specific. Engines won't react 100% the same.
@@ -131,7 +131,7 @@ module BABYLON {
         public setMotor(force?: number, maxForce?: number) {
             this._physicsPlugin.setMotor(this, force || 0, maxForce);
         }
-        
+
         /**
          * Set the motor's limits.
          * Attention, this function is plugin specific. Engines won't react 100% the same.
@@ -140,16 +140,16 @@ module BABYLON {
             this._physicsPlugin.setLimit(this, upperLimit, lowerLimit);
         }
     }
-    
+
     /**
      * This class represents a dual hinge physics joint (same as wheel joint)
      */
     export class Hinge2Joint extends MotorEnabledJoint {
-        
-        constructor(jointData:PhysicsJointData) {
+
+        constructor(jointData: PhysicsJointData) {
             super(PhysicsJoint.Hinge2Joint, jointData);
         }
-        
+
         /**
          * Set the motor values.
          * Attention, this function is plugin specific. Engines won't react 100% the same.
@@ -160,7 +160,7 @@ module BABYLON {
         public setMotor(force?: number, maxForce?: number, motorIndex: number = 0) {
             this._physicsPlugin.setMotor(this, force || 0, maxForce, motorIndex);
         }
-        
+
         /**
          * Set the motor limits.
          * Attention, this function is plugin specific. Engines won't react 100% the same.
@@ -189,5 +189,6 @@ module BABYLON {
         length: number;
         stiffness: number;
         damping: number;
+        forceApplicationCallback: () => void;
     }
 }