Sync optimisation update (playcanvas#1583)

e-strokov · web-flow · commit 9caa65a6aaca · 2019-06-03T18:27:05.000+01:00
* Frozen property added to optimise SyncHierarchy

* Core review feedback - comment added.

* A fix for _frozen flag issue reported on GH
diff --git a/src/scene/graph-node.js b/src/scene/graph-node.js
@@ -35,6 +35,9 @@ Object.assign(pc, function () {
         this._dirtyLocal = false;
         this._aabbVer = 0;
 
+        // _frozen flag marks the node to ignore hierarchy sync etirely (including children nodes)
+        // engine code automatically freezes and unfreezes objects whenever required
+        // segrigating dynamic and stationary nodes into subhierarchies allows to reduce sync time significantly
         this._frozen = false;
 
         this.worldTransform = new pc.Mat4();
@@ -1141,6 +1144,9 @@ Object.assign(pc, function () {
 
             // The child (plus subhierarchy) will need world transforms to be recalculated
             node._dirtifyWorld();
+            // node might be already marked as dirty, in that case the whole chain stays frozen, so let's enforce unfreeze
+            if (this._frozen)
+                node._unfreezeParentToRoot();
 
             // alert an entity that it has been inserted
             if (node.fire) node.fire('insert', this);
diff --git a/tests/scene/test_graphnode.js b/tests/scene/test_graphnode.js
@@ -368,5 +368,17 @@ describe('pc.GraphNode', function () {
 
     });
 
+    it('GraphNode: frozen flag after reparent and sync for world-dirty node', function () {
+        var p = new pc.GraphNode('parent');
+        p.syncHierarchy();
+
+        var c = new pc.GraphNode('child');
+        c._dirtifyWorld();
+
+        p.addChild(c);
+        p.syncHierarchy();
+
+        equal(c._frozen, true);
+    });
 
 });
