overte/interface/src/VoxelSystem.cpp

//
//  Cube.cpp
//  interface
//
//  Created by Philip on 12/31/12.
//  Copyright (c) 2012 High Fidelity, Inc. All rights reserved.
//
#ifdef _WIN32
#define _timeval_
#define _USE_MATH_DEFINES
#endif
#include <cstring>
#include <cmath>
#include <iostream> // to load voxels from file
#include <fstream> // to load voxels from file
#include <SharedUtil.h>
#include <PacketHeaders.h>
#include <OctalCode.h>
#include <pthread.h>
#include "Log.h"

#include "VoxelSystem.h"

const int MAX_VOXELS_PER_SYSTEM = 250000;

const int VERTICES_PER_VOXEL = 8;
const int VERTEX_POINTS_PER_VOXEL = 3 * VERTICES_PER_VOXEL;
const int INDICES_PER_VOXEL = 3 * 12;

float identityVertices[] = { 0, 0, 0,
                            1, 0, 0,
                            1, 1, 0,
                            0, 1, 0,
                            0, 0, 1,
                            1, 0, 1,
                            1, 1, 1,
                            0, 1, 1 };

GLubyte identityIndices[] = { 0,1,2, 0,2,3,
                              0,1,5, 0,4,5,
                              0,3,7, 0,4,7,
                              1,2,6, 1,5,6,
                              2,3,7, 2,6,7,
                              4,5,6, 4,6,7 };

VoxelSystem::VoxelSystem() {
    voxelsRendered = 0;
    tree = new VoxelTree();
    pthread_mutex_init(&bufferWriteLock, NULL);
}

VoxelSystem::~VoxelSystem() {    
    delete[] readVerticesArray;
    delete[] writeVerticesArray;
    delete[] readColorsArray;
    delete[] writeColorsArray;
    delete tree;
    pthread_mutex_destroy(&bufferWriteLock);
}

void VoxelSystem::setViewerHead(Head *newViewerHead) {
    viewerHead = newViewerHead;
}

//////////////////////////////////////////////////////////////////////////////////////////
// Method:      VoxelSystem::loadVoxelsFile()
// Description: Loads HiFidelity encoded Voxels from a binary file. The current file
//              format is a stream of single voxels with NO color data. Currently
//              colors are set randomly
// Complaints:  Brad :)
// To Do:       Need to add color data to the file.
void VoxelSystem::loadVoxelsFile(const char* fileName, bool wantColorRandomizer) {
    
    tree->loadVoxelsFile(fileName,wantColorRandomizer);
    
    copyWrittenDataToReadArrays();
}

//////////////////////////////////////////////////////////////////////////////////////////
// Method:      VoxelSystem::createSphere()
// Description: Creates a sphere of voxels in the local system at a given location/radius
// To Do:       Move this function someplace better? I put it here because we need a
//              mechanism to tell the system to redraw it's arrays after voxels are done
//              being added. This is a concept mostly only understood by VoxelSystem.
// Complaints:  Brad :)
void VoxelSystem::createSphere(float r,float xc, float yc, float zc, float s, bool solid, bool wantColorRandomizer) {

    tree->createSphere(r,xc,yc,zc,s,solid,wantColorRandomizer);
    setupNewVoxelsForDrawing();
}

long int VoxelSystem::getVoxelsCreated() {
    return tree->voxelsCreated;
}

float VoxelSystem::getVoxelsCreatedPerSecondAverage() {
    return (1 / tree->voxelsCreatedStats.getEventDeltaAverage());
}

long int VoxelSystem::getVoxelsColored() {
    return tree->voxelsColored;
}

float VoxelSystem::getVoxelsColoredPerSecondAverage() {
    return (1 / tree->voxelsColoredStats.getEventDeltaAverage());
}

long int VoxelSystem::getVoxelsBytesRead() {
    return tree->voxelsBytesRead;
}

float VoxelSystem::getVoxelsBytesReadPerSecondAverage() {
    return tree->voxelsBytesReadStats.getAverageSampleValuePerSecond();
}


void VoxelSystem::parseData(unsigned char* sourceBuffer, int numBytes) {

    unsigned char command = *sourceBuffer;
    unsigned char *voxelData = sourceBuffer + 1;
    
    switch(command) {
        case PACKET_HEADER_VOXEL_DATA:
            // ask the VoxelTree to read the bitstream into the tree
            tree->readBitstreamToTree(voxelData, numBytes - 1);
        break;
        case PACKET_HEADER_ERASE_VOXEL:
            // ask the tree to read the "remove" bitstream
            tree->processRemoveVoxelBitstream(sourceBuffer, numBytes);
        break;
        case PACKET_HEADER_Z_COMMAND:

            // the Z command is a special command that allows the sender to send high level semantic
            // requests, like erase all, or add sphere scene, different receivers may handle these 
            // messages differently
            char* packetData = (char *)sourceBuffer;
            char* command = &packetData[1]; // start of the command
            int commandLength = strlen(command); // commands are null terminated strings
            int totalLength = 1+commandLength+1;

            printLog("got Z message len(%d)= %s\n", numBytes, command);

            while (totalLength <= numBytes) {
                if (0==strcmp(command,(char*)"erase all")) {
                    printLog("got Z message == erase all\n");
                    tree->eraseAllVoxels();
                }
                if (0==strcmp(command,(char*)"add scene")) {
                    printLog("got Z message == add scene - NOT SUPPORTED ON INTERFACE\n");
                }
                totalLength += commandLength+1;
            }
        break;
    }
    
    setupNewVoxelsForDrawing();
}

void VoxelSystem::setupNewVoxelsForDrawing() {
    // reset the verticesEndPointer so we're writing to the beginning of the array
    writeVerticesEndPointer = writeVerticesArray;
    // call recursive function to populate in memory arrays
    // it will return the number of voxels added
    glm::vec3 treeRoot = glm::vec3(0,0,0);
    voxelsRendered = treeToArrays(tree->rootNode, treeRoot);
    // copy the newly written data to the arrays designated for reading
    copyWrittenDataToReadArrays();
}

void VoxelSystem::copyWrittenDataToReadArrays() {
    // lock on the buffer write lock so we can't modify the data when the GPU is reading it
    pthread_mutex_lock(&bufferWriteLock);
    // store a pointer to the current end so it doesn't change during copy
    GLfloat *endOfCurrentVerticesData = writeVerticesEndPointer;
    // copy the vertices and colors
    memcpy(readVerticesArray, writeVerticesArray, (endOfCurrentVerticesData - writeVerticesArray) * sizeof(GLfloat));
    memcpy(readColorsArray, writeColorsArray, (endOfCurrentVerticesData - writeVerticesArray) * sizeof(GLubyte));
    // set the read vertices end pointer to the correct spot so the GPU knows how much to pull
    readVerticesEndPointer = readVerticesArray + (endOfCurrentVerticesData - writeVerticesArray);
    pthread_mutex_unlock(&bufferWriteLock);
}

int VoxelSystem::treeToArrays(VoxelNode *currentNode, const glm::vec3&  nodePosition) {
    int voxelsAdded = 0;

    float halfUnitForVoxel = powf(0.5, *currentNode->octalCode) * (0.5 * TREE_SCALE);
    glm::vec3 viewerPosition = viewerHead->getBodyPosition();

    // debug LOD code
    glm::vec3 debugNodePosition;
    copyFirstVertexForCode(currentNode->octalCode,(float*)&debugNodePosition);

    //printf("-----------------\n");
    //printf("halfUnitForVoxel=%f\n",halfUnitForVoxel);
    //printf("viewer.x=%f y=%f z=%f \n", viewerPosition.x, viewerPosition.y, viewerPosition.z);
    //printf("node.x=%f y=%f z=%f \n", nodePosition[0], nodePosition[1], nodePosition[2]);
    //printf("debugNodePosition.x=%f y=%f z=%f \n", debugNodePosition[0], debugNodePosition[1], debugNodePosition[2]);

    float distanceToVoxelCenter = sqrtf(powf(viewerPosition.x - nodePosition[0] - halfUnitForVoxel, 2) +
                                        powf(viewerPosition.y - nodePosition[1] - halfUnitForVoxel, 2) +
                                        powf(viewerPosition.z - nodePosition[2] - halfUnitForVoxel, 2));

    int renderLevel = *currentNode->octalCode + 1;
    int boundaryPosition = boundaryDistanceForRenderLevel(renderLevel);
    //printLog("treeToArrays() renderLevel=%d distanceToVoxelCenter=%f boundaryPosition=%d\n",
    //    renderLevel,distanceToVoxelCenter,boundaryPosition);

    bool alwaysDraw = false; // XXXBHG - temporary debug code. Flip this to true to disable LOD blurring

    if (alwaysDraw || distanceToVoxelCenter < boundaryPosition) {
        for (int i = 0; i < 8; i++) {
            // check if there is a child here
            if (currentNode->children[i] != NULL) {
                
                glm::vec3 childNodePosition;
                copyFirstVertexForCode(currentNode->children[i]->octalCode,(float*)&childNodePosition);
                childNodePosition *= (float)TREE_SCALE; // scale it up
                
                /**** disabled ************************************************************************************************
                // Note: Stephen, I intentionally left this in so you would talk to me about it. Here's the deal, this code
                // doesn't seem to work correctly. It returns X and Z flipped and the values are negative. Since we use the
                // firstVertexForCode() function below to calculate the child vertex and that DOES work, I've decided to use
                // that function to calculate our position for LOD handling.
                //
                // calculate the child's position based on the parent position
                for (int j = 0; j < 3; j++) {
                    childNodePosition[j] = nodePosition[j];
                    
                    if (oneAtBit(branchIndexWithDescendant(currentNode->octalCode,currentNode->children[i]->octalCode),(7 - j))) {
                        childNodePosition[j] -= (powf(0.5, *currentNode->children[i]->octalCode) * TREE_SCALE);
                    }
                }
                **** disabled ************************************************************************************************/
                voxelsAdded += treeToArrays(currentNode->children[i], childNodePosition);
            }
        }
    }

    // if we didn't get any voxels added then we're a leaf
    // add our vertex and color information to the interleaved array
    if (voxelsAdded == 0 && currentNode->isColored()) {
        float startVertex[3];
        copyFirstVertexForCode(currentNode->octalCode,(float*)&startVertex);
        float voxelScale = 1 / powf(2, *currentNode->octalCode);
        
        // populate the array with points for the 8 vertices
        // and RGB color for each added vertex
        for (int j = 0; j < VERTEX_POINTS_PER_VOXEL; j++ ) {
            *writeVerticesEndPointer = startVertex[j % 3] + (identityVertices[j] * voxelScale);
            *(writeColorsArray + (writeVerticesEndPointer - writeVerticesArray)) = currentNode->getColor()[j % 3];
            
            writeVerticesEndPointer++;
        }
        voxelsAdded++;
    }

    return voxelsAdded;
}

VoxelSystem* VoxelSystem::clone() const {
    // this still needs to be implemented, will need to be used if VoxelSystem is attached to agent
    return NULL;
}

void VoxelSystem::init() {
    // prep the data structures for incoming voxel data
    writeVerticesEndPointer = writeVerticesArray = new GLfloat[VERTEX_POINTS_PER_VOXEL * MAX_VOXELS_PER_SYSTEM];
    readVerticesEndPointer = readVerticesArray = new GLfloat[VERTEX_POINTS_PER_VOXEL * MAX_VOXELS_PER_SYSTEM];
    writeColorsArray = new GLubyte[VERTEX_POINTS_PER_VOXEL * MAX_VOXELS_PER_SYSTEM];
    readColorsArray = new GLubyte[VERTEX_POINTS_PER_VOXEL * MAX_VOXELS_PER_SYSTEM];

    GLuint *indicesArray = new GLuint[INDICES_PER_VOXEL * MAX_VOXELS_PER_SYSTEM];
    
    // populate the indicesArray
    // this will not change given new voxels, so we can set it all up now
    for (int n = 0; n < MAX_VOXELS_PER_SYSTEM; n++) {
        // fill the indices array
        int voxelIndexOffset = n * INDICES_PER_VOXEL;
        GLuint *currentIndicesPos = indicesArray + voxelIndexOffset;
        int startIndex = (n * VERTICES_PER_VOXEL);
        
        for (int i = 0; i < INDICES_PER_VOXEL; i++) {
            // add indices for this side of the cube
            currentIndicesPos[i] = startIndex + identityIndices[i];
        }
    }
    
    // VBO for the verticesArray
    glGenBuffers(1, &vboVerticesID);
    glBindBuffer(GL_ARRAY_BUFFER, vboVerticesID);
    glBufferData(GL_ARRAY_BUFFER, VERTEX_POINTS_PER_VOXEL * sizeof(GLfloat) * MAX_VOXELS_PER_SYSTEM, NULL, GL_DYNAMIC_DRAW);
    
    // VBO for colorsArray
    glGenBuffers(1, &vboColorsID);
    glBindBuffer(GL_ARRAY_BUFFER, vboColorsID);
    glBufferData(GL_ARRAY_BUFFER, VERTEX_POINTS_PER_VOXEL * sizeof(GLubyte) * MAX_VOXELS_PER_SYSTEM, NULL, GL_DYNAMIC_DRAW);
    
    // VBO for the indicesArray
    glGenBuffers(1, &vboIndicesID);
    glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, vboIndicesID);
    glBufferData(GL_ELEMENT_ARRAY_BUFFER,
                 INDICES_PER_VOXEL * sizeof(GLuint) * MAX_VOXELS_PER_SYSTEM,
                 indicesArray, GL_STATIC_DRAW);
    
    // delete the indices array that is no longer needed
    delete[] indicesArray;
}

void VoxelSystem::render() {

    glPushMatrix();
    
    if (readVerticesEndPointer != readVerticesArray) {
        // try to lock on the buffer write
        // just avoid pulling new data if it is currently being written
        if (pthread_mutex_trylock(&bufferWriteLock) == 0) {
            
            glBindBuffer(GL_ARRAY_BUFFER, vboVerticesID);
            glBufferSubData(GL_ARRAY_BUFFER, 0, (readVerticesEndPointer - readVerticesArray) * sizeof(GLfloat), readVerticesArray);
            
            glBindBuffer(GL_ARRAY_BUFFER, vboColorsID);
            glBufferSubData(GL_ARRAY_BUFFER, 0, (readVerticesEndPointer - readVerticesArray) * sizeof(GLubyte), readColorsArray);
            
            readVerticesEndPointer = readVerticesArray;
            
            pthread_mutex_unlock(&bufferWriteLock);
        }
    }

    // tell OpenGL where to find vertex and color information
    glEnableClientState(GL_VERTEX_ARRAY);
    glEnableClientState(GL_COLOR_ARRAY);
    
    glBindBuffer(GL_ARRAY_BUFFER, vboVerticesID);
    glVertexPointer(3, GL_FLOAT, 0, 0);
    
    glBindBuffer(GL_ARRAY_BUFFER, vboColorsID);
    glColorPointer(3, GL_UNSIGNED_BYTE, 0, 0);
   
    // draw the number of voxels we have
    glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, vboIndicesID);
    glScalef(10, 10, 10);
    glDrawElements(GL_TRIANGLES, 36 * voxelsRendered, GL_UNSIGNED_INT, 0);
    
    // deactivate vertex and color arrays after drawing
    glDisableClientState(GL_VERTEX_ARRAY);
    glDisableClientState(GL_COLOR_ARRAY);
    
    // bind with 0 to switch back to normal operation
    glBindBuffer(GL_ARRAY_BUFFER, 0);
    glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, 0);
    
    // scale back down to 1 so heads aren't massive
    glPopMatrix();
}

void VoxelSystem::simulate(float deltaTime) {
    
}

int VoxelSystem::_nodeCount = 0;

bool VoxelSystem::randomColorOperation(VoxelNode* node, bool down, void* extraData) {

    // we do our operations on the way up!
    if (down) {
        return true;
    }
    
    _nodeCount++;
    if (node->isColored()) {
        nodeColor newColor = { 0,0,0,1 };
        newColor[0] = randomColorValue(150);
        newColor[1] = randomColorValue(150);
        newColor[1] = randomColorValue(150);

        //printf("randomize color node %d was %x,%x,%x NOW %x,%x,%x\n",
        //      _nodeCount,node->getTrueColor()[0],node->getTrueColor()[1],node->getTrueColor()[2],
        //      newColor[0],newColor[1],newColor[2]);
        node->setColor(newColor);
    } else {
        //printf("not randomizing color node of %d since it has no color\n",_nodeCount);
    }
    return true;
}

void VoxelSystem::randomizeVoxelColors() {
    _nodeCount = 0;
    tree->recurseTreeWithOperation(randomColorOperation);
    printf("setting randomized true color for %d nodes\n",_nodeCount);
    setupNewVoxelsForDrawing();
}

bool VoxelSystem::falseColorizeRandomOperation(VoxelNode* node, bool down, void* extraData) {

    // we do our operations on the way up!
    if (down) {
        return true;
    }
    
    _nodeCount++;
    
    // always false colorize
    unsigned char newR = randomColorValue(150);
    unsigned char newG = randomColorValue(150);
    unsigned char newB = randomColorValue(150);

    printf("randomize FALSE color node %d was %x,%x,%x NOW %x,%x,%x\n",
          _nodeCount,node->getTrueColor()[0],node->getTrueColor()[1],node->getTrueColor()[2],
          newR,newG,newB);
    node->setFalseColor(newR,newG,newB);

    return true; // keep going!
}

void VoxelSystem::falseColorizeRandom() {
    _nodeCount = 0;
    tree->recurseTreeWithOperation(falseColorizeRandomOperation);
    printf("setting randomized false color for %d nodes\n",_nodeCount);
    setupNewVoxelsForDrawing();
}

bool VoxelSystem::trueColorizeOperation(VoxelNode* node, bool down, void* extraData) {

    // we do our operations on the way up!
    if (down) {
        return true;
    }
    
    _nodeCount++;
    node->setFalseColored(false);
    //printf("setting true color for node %d\n",_nodeCount);
    return true;
}

void VoxelSystem::trueColorize() {
    _nodeCount = 0;
    tree->recurseTreeWithOperation(trueColorizeOperation);
    printf("setting true color for %d nodes\n",_nodeCount);
    setupNewVoxelsForDrawing();
}

// Will false colorize voxels that are not in view
bool VoxelSystem::falseColorizeInViewOperation(VoxelNode* node, bool down, void* extraData) {

    // we do our operations on the way up!
    if (down) {
        return true;
    }
    
    ViewFrustum* viewFrustum = (ViewFrustum*) extraData;
    
    _nodeCount++;
    
    // only do this for truely colored voxels...
    if (node->isColored()) {
        // first calculate the AAbox for the voxel
        AABox voxelBox;
        node->getAABox(voxelBox);
    
        voxelBox.scale(TREE_SCALE);
    
        printf("voxelBox corner=(%f,%f,%f) x=%f\n",
            voxelBox.getCorner().x, voxelBox.getCorner().y, voxelBox.getCorner().z,
            voxelBox.getSize().x);
    
        // If the voxel is outside of the view frustum, then false color it red
        if (ViewFrustum::OUTSIDE == viewFrustum->pointInFrustum(voxelBox.getCorner())) {
            // Out of view voxels are colored RED
            unsigned char newR = 255;
            unsigned char newG = 0;
            unsigned char newB = 0;

            //printf("voxel OUTSIDE view - FALSE colorizing node %d TRUE color is %x,%x,%x  \n",
            //     _nodeCount,node->getTrueColor()[0],node->getTrueColor()[1],node->getTrueColor()[2]);
            node->setFalseColor(newR,newG,newB);
        } else {
            printf("voxel NOT OUTSIDE view\n");
        }
    } else {
        printf("voxel not colored, don't consider it\n");
    }
    
    return true; // keep going!
}

void VoxelSystem::falseColorizeInView(ViewFrustum* viewFrustum) {
    _nodeCount = 0;
    tree->recurseTreeWithOperation(falseColorizeInViewOperation,(void*)viewFrustum);
    printf("setting in view false color for %d nodes\n",_nodeCount);
    setupNewVoxelsForDrawing();
}

// Will false colorize voxels based on distance from view
bool VoxelSystem::falseColorizeDistanceFromViewOperation(VoxelNode* node, bool down, void* extraData) {

    //printf("falseColorizeDistanceFromViewOperation() down=%s\n",(down ? "TRUE" : "FALSE"));

    // we do our operations on the way up!
    if (down) {
        return true;
    }

    ViewFrustum* viewFrustum = (ViewFrustum*) extraData;
    
    // only do this for truly colored voxels...
    if (node->isColored()) {

        // We need our distance for both up and down
        glm::vec3 nodePosition;
        float* startVertex = firstVertexForCode(node->octalCode);
        nodePosition.x = startVertex[0];
        nodePosition.y = startVertex[1];
        nodePosition.z = startVertex[2];
        delete startVertex;

        // scale up the node position
        nodePosition = nodePosition*(float)TREE_SCALE;
        
        float halfUnitForVoxel = powf(0.5, *node->octalCode) * (0.5 * TREE_SCALE);
        glm::vec3 viewerPosition = viewFrustum->getPosition();
        
        //printf("halfUnitForVoxel=%f\n",halfUnitForVoxel);
        //printf("viewer.x=%f y=%f z=%f \n", viewerPosition.x, viewerPosition.y, viewerPosition.z);
        //printf("node.x=%f y=%f z=%f \n", nodePosition.x, nodePosition.y, nodePosition.z);

        float distance = sqrtf(powf(viewerPosition.x - nodePosition.x - halfUnitForVoxel, 2) +
                                            powf(viewerPosition.y - nodePosition.y - halfUnitForVoxel, 2) +
                                            powf(viewerPosition.z - nodePosition.z - halfUnitForVoxel, 2));

        // actually colorize
        _nodeCount++;

        float distanceRatio = (_minDistance==_maxDistance) ? 1 : (distance - _minDistance)/(_maxDistance - _minDistance);
        
        // We want to colorize this in 16 bug chunks of color
        const unsigned char maxColor = 255;
        const unsigned char colorBands = 16;
        const unsigned char gradientOver = 128;
        unsigned char colorBand = (colorBands*distanceRatio);
        unsigned char newR = (colorBand*(gradientOver/colorBands))+(maxColor-gradientOver);
        unsigned char newG = 0;
        unsigned char newB = 0;
        //printf("Setting color down=%s distance=%f min=%f max=%f distanceRatio=%f color=%d \n", 
        //    (down ? "TRUE" : "FALSE"), distance, _minDistance, _maxDistance, distanceRatio, (int)newR);

        node->setFalseColor(newR,newG,newB);
    } else {
        //printf("voxel not colored, don't consider it - down=%s\n",(down ? "TRUE" : "FALSE"));
    }
    return true; // keep going!
}

float VoxelSystem::_maxDistance = 0.0;
float VoxelSystem::_minDistance = FLT_MAX;

// Helper function will get the distance from view range, would be nice if you could just keep track
// of this as voxels are created and/or colored... seems like some transform math could do that so
// we wouldn't need to do two passes of the tree
bool VoxelSystem::getDistanceFromViewRangeOperation(VoxelNode* node, bool down, void* extraData) {

    // we do our operations on the way up!
    if (down) {
        return true;
    }

    //printf("getDistanceFromViewRangeOperation() down=%s\n",(down ? "TRUE" : "FALSE"));

    ViewFrustum* viewFrustum = (ViewFrustum*) extraData;
    
    // only do this for truly colored voxels...
    if (node->isColored()) {

        // We need our distance for both up and down
        glm::vec3 nodePosition;
        float* startVertex = firstVertexForCode(node->octalCode);
        nodePosition.x = startVertex[0];
        nodePosition.y = startVertex[1];
        nodePosition.z = startVertex[2];
        delete startVertex;

        // scale up the node position
        nodePosition = nodePosition*(float)TREE_SCALE;

        float halfUnitForVoxel = powf(0.5, *node->octalCode) * (0.5 * TREE_SCALE);
        glm::vec3 viewerPosition = viewFrustum->getPosition();

        float distance = sqrtf(powf(viewerPosition.x - nodePosition.x - halfUnitForVoxel, 2) +
                                            powf(viewerPosition.y - nodePosition.y - halfUnitForVoxel, 2) +
                                            powf(viewerPosition.z - nodePosition.z - halfUnitForVoxel, 2));

        // on way down, calculate the range of distances
        if (distance > _maxDistance) {
            _maxDistance = distance;
            //printf("new maxDistance=%f down=%s\n",_maxDistance, (down ? "TRUE" : "FALSE"));
        }
        if (distance < _minDistance) {
            _minDistance = distance;
            //printf("new minDistance=%f down=%s\n",_minDistance, (down ? "TRUE" : "FALSE"));
        }

        _nodeCount++;
    }
    return true; // keep going!
}

void VoxelSystem::falseColorizeDistanceFromView(ViewFrustum* viewFrustum) {
    _nodeCount = 0;

    _maxDistance = 0.0;
    _minDistance = FLT_MAX;
    tree->recurseTreeWithOperation(getDistanceFromViewRangeOperation,(void*)viewFrustum);
    printf("determining distance range for %d nodes\n",_nodeCount);

    _nodeCount = 0;
    
    tree->recurseTreeWithOperation(falseColorizeDistanceFromViewOperation,(void*)viewFrustum);
    printf("setting in distance false color for %d nodes\n",_nodeCount);
    setupNewVoxelsForDrawing();
}