From ae3db89f63005a902f239159b1cb5b10e9556f52 Mon Sep 17 00:00:00 2001
From: ZappoMan <bradh@konamoxt.com>
Date: Thu, 6 Jun 2013 10:55:11 -0700
Subject: [PATCH] added method for general subtree change bookkeeping

---
 libraries/voxels/src/VoxelNode.cpp | 17 +++++++++++++++++
 libraries/voxels/src/VoxelNode.h   |  3 +++
 libraries/voxels/src/VoxelTree.cpp | 10 ++++++----
 libraries/voxels/src/VoxelTree.h   |  2 ++
 4 files changed, 28 insertions(+), 4 deletions(-)

diff --git a/libraries/voxels/src/VoxelNode.cpp b/libraries/voxels/src/VoxelNode.cpp
index b5c5b10cac..bd8feadb35 100644
--- a/libraries/voxels/src/VoxelNode.cpp
+++ b/libraries/voxels/src/VoxelNode.cpp
@@ -12,6 +12,7 @@
 #include "SharedUtil.h"
 #include "Log.h"
 #include "VoxelNode.h"
+#include "VoxelTree.h"
 #include "VoxelConstants.h"
 #include "OctalCode.h"
 #include "AABox.h"
@@ -61,6 +62,22 @@ VoxelNode::~VoxelNode() {
     }
 }
 
+// This method is called by VoxelTree when the subtree below this node
+// is known to have changed. It's intended to be used as a place to do
+// bookkeeping that a node may need to do when the subtree below it has
+// changed. However, you should hopefully make your bookkeeping relatively
+// localized, because this method will get called for every node in an
+// recursive unwinding case like delete or add voxel
+void VoxelNode::handleSubtreeChanged(VoxelTree* myTree) {
+    markWithChangedTime();
+    
+    // here's a good place to do color re-averaging...
+    if (myTree->getShouldReaverage()) {
+        setColorFromAverageOfChildren();
+    }
+}
+
+
 void VoxelNode::setShouldRender(bool shouldRender) {
     // if shouldRender is changing, then consider ourselves dirty
     if (shouldRender != _shouldRender) {
diff --git a/libraries/voxels/src/VoxelNode.h b/libraries/voxels/src/VoxelNode.h
index 997c495693..3fd8e67e9c 100644
--- a/libraries/voxels/src/VoxelNode.h
+++ b/libraries/voxels/src/VoxelNode.h
@@ -14,6 +14,8 @@
 #include "ViewFrustum.h"
 #include "VoxelConstants.h"
 
+class VoxelTree; // forward delclaration
+
 typedef unsigned char colorPart;
 typedef unsigned char nodeColor[4];
 typedef unsigned char rgbColor[3];
@@ -79,6 +81,7 @@ public:
     void clearDirtyBit() { _isDirty = false; };
     bool hasChangedSince(double time) const { return (_lastChanged > time);  };
     void markWithChangedTime() { _lastChanged = usecTimestampNow();  };
+    void handleSubtreeChanged(VoxelTree* myTree);
     
     glBufferIndex getBufferIndex() const { return _glBufferIndex; };
     bool isKnownBufferIndex() const { return (_glBufferIndex != GLBUFFER_INDEX_UNKNOWN); };
diff --git a/libraries/voxels/src/VoxelTree.cpp b/libraries/voxels/src/VoxelTree.cpp
index 30c61fe4a1..ab724d92a9 100644
--- a/libraries/voxels/src/VoxelTree.cpp
+++ b/libraries/voxels/src/VoxelTree.cpp
@@ -388,9 +388,10 @@ void VoxelTree::deleteVoxelCodeFromTreeRecursion(VoxelNode* node, void* extraDat
         }
     }
     
-    // If the lower level did some work, then we need to track our lastChanged status.
+    // If the lower level did some work, then we need to let this node know, so it can
+    // do any bookkeeping it wants to, like color re-averaging, time stamp marking, etc
     if (args->pathChanged) {
-        node->markWithChangedTime();
+        node->handleSubtreeChanged(this);
     }
 }
 
@@ -482,9 +483,10 @@ void VoxelTree::readCodeColorBufferToTreeRecursion(VoxelNode* node, void* extraD
 
     // Unwinding...
     
-    // If the lower level did some work, then we need to track our lastChanged status.
+    // If the lower level did some work, then we need to let this node know, so it can
+    // do any bookkeeping it wants to, like color re-averaging, time stamp marking, etc
     if (args->pathChanged) {
-        node->markWithChangedTime();
+        node->handleSubtreeChanged(this);
     }
 }
 
diff --git a/libraries/voxels/src/VoxelTree.h b/libraries/voxels/src/VoxelTree.h
index 1158596527..a238cb603a 100644
--- a/libraries/voxels/src/VoxelTree.h
+++ b/libraries/voxels/src/VoxelTree.h
@@ -99,6 +99,8 @@ public:
     void copySubTreeIntoNewTree(VoxelNode* startNode, VoxelTree* destinationTree, bool rebaseToRoot);
     void copyFromTreeIntoSubTree(VoxelTree* sourceTree, VoxelNode* destinationNode);
     
+    bool getShouldReaverage() const { return _shouldReaverage; }
+    
 private:
     void deleteVoxelCodeFromTreeRecursion(VoxelNode* node, void* extraData);
     void readCodeColorBufferToTreeRecursion(VoxelNode* node, void* extraData);