Merge pull request #594 from scenerygraphics/fix-scene-rebuilds

Only rebuild scene graph once per Renderer frame

Author: kephale

src/main/kotlin/sc/iview/SciView.kt

@@ -213,17 +213,21 @@ class SciView : SceneryBase, CalibratedRealInterval<CalibratedAxis> {
      */
     private var animating = false
 
+    /**
+     * Track whether the scene changed and needs an update in the next tick
+     */
+    public var needSceneUpdate: Boolean = false
+
     /**
      * This tracks the actively selected Node in the scene
      */
     var activeNode: Node? = null
         private set
 
-    /*
-     * Return the SciJava Display that contains SciView
-     *//*
-     * Set the SciJava Display
-     */  var display: Display<*>? = null
+    /**
+     * The SciJava Display that contains SciView
+     */
+    var display: Display<*>? = null
 
     /**
      * List of available LUTs for caching
@@ -410,6 +414,22 @@ class SciView : SceneryBase, CalibratedRealInterval<CalibratedAxis> {
         controls = Controls(this)
 
         imageToVolumeMap = HashMap<Any, Volume>()
+
+        // Create a hook for running after each frame is rendered
+        renderer?.runAfterRendering?.add { this.updateAferRendering() }
+    }
+
+    /**
+     * A method that is run after the scene is rendered
+     */
+    private fun updateAferRendering() {
+        if(needSceneUpdate) {
+            mainWindow.rebuildSceneTree()
+            if (activeNode == null){
+                (mainWindow as SwingMainWindow).nodePropertyEditor.updateProperties(null)
+            }
+            needSceneUpdate = false
+        }
     }
 
     fun toggleSidebar(): Boolean {
@@ -1026,13 +1046,13 @@ class SciView : SceneryBase, CalibratedRealInterval<CalibratedAxis> {
     @Suppress("UNUSED_PARAMETER")
     @EventHandler
     protected fun onNodeAdded(event: NodeAddedEvent?) {
-        mainWindow.rebuildSceneTree()
+        needSceneUpdate = true
     }
 
     @Suppress("UNUSED_PARAMETER")
     @EventHandler
     protected fun onNodeRemoved(event: NodeRemovedEvent?) {
-        mainWindow.rebuildSceneTree()
+        needSceneUpdate = true
     }
 
     @Suppress("UNUSED_PARAMETER")

src/main/kotlin/sc/iview/ui/SwingNodePropertyEditor.kt

@@ -149,10 +149,7 @@ class SwingNodePropertyEditor(private val sciView: SciView) : UIComponent<JPanel
     private fun onEvent(evt: NodeRemovedEvent) {
         val node = evt.node ?: return
         log.trace("Node removed: $node");
-        rebuildTree()
-        if (sciView.activeNode == null){
-            updateProperties(null)
-        }
+        sciView.needSceneUpdate = true
     }
 
     @EventHandler