add VoxelNode and VoxelTree classes for shared tree representation

shared/src/VoxelNode.cpp

@@ -0,0 +1,20 @@
+//
+//  VoxelNode.cpp
+//  hifi
+//
+//  Created by Stephen Birarda on 3/13/13.
+//
+//
+
+#include "VoxelNode.h"
+
+VoxelNode::VoxelNode() {
+    
+    // default pointers to child nodes to NULL
+    for (int i = 0; i < 8; i++) {
+        children[i] = NULL;
+    }
+}
+
+
+

shared/src/VoxelNode.h

@@ -0,0 +1,23 @@
+//
+//  VoxelNode.h
+//  hifi
+//
+//  Created by Stephen Birarda on 3/13/13.
+//
+//
+
+#ifndef __hifi__VoxelNode__
+#define __hifi__VoxelNode__
+
+#include <iostream>
+
+class VoxelNode {
+public:
+    VoxelNode();
+    
+    unsigned char color[4];
+    VoxelNode *children[8];
+    unsigned char childMask;
+};
+
+#endif /* defined(__hifi__VoxelNode__) */

shared/src/VoxelTree.cpp

@@ -0,0 +1,70 @@
+//
+//  VoxelTree.cpp
+//  hifi
+//
+//  Created by Stephen Birarda on 3/13/13.
+//  Copyright (c) 2013 High Fidelity, Inc. All rights reserved.
+//
+
+#include "VoxelTree.h"
+
+const int MAX_VOXEL_PACKET_SIZE = 1492;
+const int MAX_TREE_SIZE_BYTES = 26;
+
+VoxelTree::VoxelTree() {
+    rootNode = new VoxelNode();
+}
+
+unsigned char * VoxelTree::loadBitstream(unsigned char * bitstreamBuffer, VoxelNode *bitstreamRootNode, unsigned char ** startSplitPtr) {
+    static unsigned char **packetSplitPtr = startSplitPtr;
+    
+    if (bitstreamRootNode->childMask != 0) {
+        
+        if ((bitstreamBuffer + MAX_TREE_SIZE_BYTES - *packetSplitPtr) > MAX_VOXEL_PACKET_SIZE) {
+            // we need to add a packet split here
+            
+            // add the octal code for the current root
+            
+            // increment packetSplitPtr and set the pointer it points to
+            // to the beginning of the next tree section
+            *(++packetSplitPtr) = bitstreamBuffer;
+        }
+        
+        // default color mask is 0, increment pointer for colors
+        *(bitstreamBuffer++) = 0;
+        
+        // keep a colorPointer so we can check how many colors were added
+        unsigned char *colorPointer = bitstreamBuffer;
+        
+        for (int i = 0; i < 8; i++) {
+            // grab this child
+            VoxelNode *child = bitstreamRootNode->children[i];
+            
+            // check if the child exists and is not transparent
+            if (child != NULL && child->color[3] != 0) {
+                
+                // copy in the childs color to bitstreamBuffer
+                memcpy(colorPointer, child->color, 3);
+                colorPointer += 3;
+                
+                // set the colorMask by bitshifting the value of childExists
+                *(bitstreamBuffer - 1) += (1 << (7 - i));
+            }
+        }
+        
+        // push the bitstreamBuffer forwards for the number of added colors
+        bitstreamBuffer += (colorPointer - bitstreamBuffer);
+        // copy the childMask to the current position of the bitstreamBuffer, and increment it
+        *(bitstreamBuffer++) = bitstreamRootNode->childMask;
+        
+        for (int j = 0; j < 8; j++) {
+            // make sure we have a child to visit
+            if (bitstreamRootNode->children[j] != NULL) {
+                bitstreamBuffer = loadBitstream(bitstreamBuffer,
+                                                bitstreamRootNode->children[j]);
+            }
+        }
+    }
+    
+    return bitstreamBuffer;
+}

shared/src/VoxelTree.h

@@ -0,0 +1,28 @@
+//
+//  VoxelTree.h
+//  hifi
+//
+//  Created by Stephen Birarda on 3/13/13.
+//  Copyright (c) 2013 High Fidelity, Inc. All rights reserved.
+//
+
+#ifndef __hifi__VoxelTree__
+#define __hifi__VoxelTree__
+
+#include <iostream>
+#include "VoxelNode.h"
+
+class VoxelTree {
+public:
+    VoxelTree();
+    
+    VoxelNode *rootNode;
+    
+    
+    void addBitstreamPacketMarker();
+    
+    void outputDebugInformation(VoxelNode *currentRootNode = NULL);    
+    unsigned char * loadBitstream(unsigned char * bitstreamBuffer, VoxelNode *bitstreamRootNode, unsigned char ** curPacketSplitPtr = NULL);
+};
+
+#endif /* defined(__hifi__VoxelTree__) */