Prevent per mesh per render closure allocation

src/Mesh/babylon.mesh.ts

@@ -973,7 +973,7 @@
         }
 
         public _processRendering(subMesh: SubMesh, effect: Effect, fillMode: number, batch: _InstancesBatch, hardwareInstancedRendering: boolean,
-            onBeforeDraw: (isInstance: boolean, world: Matrix) => void) {
+            onBeforeDraw: (isInstance: boolean, world: Matrix, effectiveMaterial?: Material) => void, effectiveMaterial?: Material) {
             var scene = this.getScene();
             var engine = scene.getEngine();
 
@@ -983,7 +983,7 @@
                 if (batch.renderSelf[subMesh._id]) {
                     // Draw
                     if (onBeforeDraw) {
-                        onBeforeDraw(false, this.getWorldMatrix());
+                        onBeforeDraw(false, this.getWorldMatrix(), effectiveMaterial);
                     }
 
                     this._draw(subMesh, fillMode, this._overridenInstanceCount);
@@ -996,7 +996,7 @@
                         // World
                         var world = instance.getWorldMatrix();
                         if (onBeforeDraw) {
-                            onBeforeDraw(true, world);
+                            onBeforeDraw(true, world, effectiveMaterial);
                         }
 
                         // Draw
@@ -1063,12 +1063,7 @@
             }
 
             // Draw
-            this._processRendering(subMesh, effect, fillMode, batch, hardwareInstancedRendering,
-                (isInstance, world) => {
-                    if (isInstance) {
-                        effectiveMaterial.bindOnlyWorldMatrix(world);
-                    }
-                });
+            this._processRendering(subMesh, effect, fillMode, batch, hardwareInstancedRendering, this._onBeforeDraw);
 
             // Unbind
             effectiveMaterial.unbind();
@@ -1092,6 +1087,12 @@
             this.onAfterRenderObservable.notifyObservers(this);
         }
 
+        private _onBeforeDraw(isInstance: boolean, world: Matrix, effectiveMaterial: Material): void {
+            if (isInstance) {
+                effectiveMaterial.bindOnlyWorldMatrix(world);
+            }
+        }
+
         /**
          * Returns an array populated with ParticleSystem objects whose the mesh is the emitter. 
          */