Fix crashing bug in voxel-server related to animation

- added VoxelNodeDeleteHook mechanism that allows users of VoxelNode to register for delete
  notification call backs
- added call back to VoxelNodeBag to remove and nodes from bags when the nodes get deleted.

libraries/voxels/src/VoxelNode.cpp

@@ -54,6 +54,8 @@ void VoxelNode::init(unsigned char * octalCode) {
 }
 
 VoxelNode::~VoxelNode() {
+    notifyDeleteHooks();
+
     delete[] _octalCode;
     
     // delete all of this node's children
@@ -387,3 +389,44 @@ float VoxelNode::distanceToPoint(const glm::vec3& point) const {
     float distance = sqrtf(glm::dot(temp, temp));
     return distance;
 }
+
+VoxelNodeDeleteHook VoxelNode::_hooks[VOXEL_NODE_MAX_DELETE_HOOKS];
+void* VoxelNode::_hooksExtraData[VOXEL_NODE_MAX_DELETE_HOOKS];
+int VoxelNode::_hooksInUse = 0;
+
+int VoxelNode::addDeleteHook(VoxelNodeDeleteHook hook, void* extraData) {
+    // If first use, initialize the _hooks array
+    if (_hooksInUse == 0) {
+        memset(_hooks, 0, sizeof(_hooks));
+        memset(_hooksExtraData, 0, sizeof(_hooksExtraData));
+    }
+    // find first available slot
+    for (int i = 0; i < VOXEL_NODE_MAX_DELETE_HOOKS; i++) {
+        if (!_hooks[i]) {
+            _hooks[i] = hook;
+            _hooksExtraData[i] = extraData;
+            _hooksInUse++;
+            return i;
+        }
+    }
+    // if we got here, then we're out of room in our hooks, return error
+    return VOXEL_NODE_NO_MORE_HOOKS_AVAILABLE;
+}
+
+void VoxelNode::removeDeleteHook(int hookID) {
+    if (_hooks[hookID]) {
+        _hooks[hookID] = NULL;
+        _hooksExtraData[hookID] = NULL;
+        _hooksInUse--;
+    }
+}
+
+void VoxelNode::notifyDeleteHooks() {
+    if (_hooksInUse > 0) {
+        for (int i = 0; i < VOXEL_NODE_MAX_DELETE_HOOKS; i++) {
+            if (_hooks[i]) {
+                _hooks[i](this, _hooksExtraData[i]);
+            }
+        }
+    }
+}

libraries/voxels/src/VoxelNode.h

@@ -15,33 +15,19 @@
 #include "VoxelConstants.h"
 
 class VoxelTree; // forward delclaration
+class VoxelNode; // forward delclaration
 
 typedef unsigned char colorPart;
 typedef unsigned char nodeColor[4];
 typedef unsigned char rgbColor[3];
 
+// Callback function, for delete hook
+typedef void (*VoxelNodeDeleteHook)(VoxelNode* node, void* extraData);
+const int VOXEL_NODE_MAX_DELETE_HOOKS = 100;
+const int VOXEL_NODE_NO_MORE_HOOKS_AVAILABLE = -1;
+
+
 class VoxelNode {
-private:
-    nodeColor _trueColor;
-#ifndef NO_FALSE_COLOR // !NO_FALSE_COLOR means, does have false color
-    nodeColor _currentColor;
-    bool      _falseColored;
-#endif
-    glBufferIndex _glBufferIndex;
-    bool _isDirty;
-    uint64_t _lastChanged;
-    bool _shouldRender;
-    bool _isStagedForDeletion;
-    AABox _box;
-    unsigned char* _octalCode;
-    VoxelNode* _children[8];
-    int _childCount;
-    float _density;             // If leaf: density = 1, if internal node: 0-1 density of voxels inside
-
-    void calculateAABox();
-
-    void init(unsigned char * octalCode);
-
 public:
     VoxelNode(); // root node constructor
     VoxelNode(unsigned char * octalCode); // regular constructor
@@ -118,6 +104,33 @@ public:
     const nodeColor& getTrueColor() const { return _trueColor; };
     const nodeColor& getColor() const { return _trueColor; };
 #endif
+
+    static int  addDeleteHook(VoxelNodeDeleteHook hook, void* extraData = NULL);
+    static void removeDeleteHook(int hookID);
+private:
+    void calculateAABox();
+    void init(unsigned char * octalCode);
+    void notifyDeleteHooks();
+
+    nodeColor _trueColor;
+#ifndef NO_FALSE_COLOR // !NO_FALSE_COLOR means, does have false color
+    nodeColor _currentColor;
+    bool      _falseColored;
+#endif
+    glBufferIndex   _glBufferIndex;
+    bool            _isDirty;
+    uint64_t        _lastChanged;
+    bool            _shouldRender;
+    bool            _isStagedForDeletion;
+    AABox           _box;
+    unsigned char*  _octalCode;
+    VoxelNode*      _children[8];
+    int             _childCount;
+    float           _density;       // If leaf: density = 1, if internal node: 0-1 density of voxels inside
+    
+    static VoxelNodeDeleteHook  _hooks[VOXEL_NODE_MAX_DELETE_HOOKS];
+    static void*                _hooksExtraData[VOXEL_NODE_MAX_DELETE_HOOKS];
+    static int                  _hooksInUse;
 };
 
 #endif /* defined(__hifi__VoxelNode__) */

libraries/voxels/src/VoxelNodeBag.cpp

@@ -9,7 +9,15 @@
 #include "VoxelNodeBag.h"
 #include <OctalCode.h>
 
+VoxelNodeBag::VoxelNodeBag() : 
+    _bagElements(NULL),
+    _elementsInUse(0),
+    _sizeOfElementsArray(0) {
+    _hookID = VoxelNode::addDeleteHook(voxelNodeDeleteHook, (void*)this);
+};
+
 VoxelNodeBag::~VoxelNodeBag() {
+    VoxelNode::removeDeleteHook(_hookID);
     deleteAll();
 }
 
@@ -118,3 +126,9 @@ void VoxelNodeBag::remove(VoxelNode* node) {
     }
 }
 
+void VoxelNodeBag::voxelNodeDeleteHook(VoxelNode* node, void* extraData) {
+    VoxelNodeBag* theBag = (VoxelNodeBag*)extraData;
+    theBag->remove(node); // note: remove can safely handle nodes that aren't in it, so we don't need to check contains()
+}
+
+

libraries/voxels/src/VoxelNodeBag.h

@@ -19,11 +19,7 @@
 class VoxelNodeBag {
 
 public:
-    VoxelNodeBag() : 
+    VoxelNodeBag();
-        _bagElements(NULL),
-        _elementsInUse(0),
-        _sizeOfElementsArray(0) {};
-        
     ~VoxelNodeBag();
     
     void insert(VoxelNode* node); // put a node into the bag
@@ -36,11 +32,14 @@ public:
 
     void deleteAll();
 
+    static void voxelNodeDeleteHook(VoxelNode* node, void* extraData);
+
 private:
     
     VoxelNode** _bagElements;
     int         _elementsInUse;
     int         _sizeOfElementsArray;
+    int         _hookID;
 };
 
 #endif /* defined(__hifi__VoxelNodeBag__) */

voxel-server/src/main.cpp

@@ -384,7 +384,6 @@ void attachVoxelNodeDataToNode(Node* newNode) {
 }
 
 int main(int argc, const char * argv[]) {
-
     pthread_mutex_init(&::treeLock, NULL);
     
     qInstallMsgHandler(sharedMessageHandler);