source: GTP/trunk/App/Demos/Vis/FriendlyCulling/src/ViewCellsTree.cpp @ 3257

#include "ViewCellsTree.h"
#include "Timer/PerfTimer.h"
#include <stack>
#include <string>

using namespace std;


// MAGIC of all bin exports
#ifndef MAGIC 
#define MAGIC 0x827923
#endif

#define VIEWCELLS_VERSION 1.0f


namespace CHCDemoEngine
{


ViewCell *ViewCellsTree::GetViewCell(const Vector3 &point) const
{
        ViewCellsTreeNode *node = mRoot;

        while (!node->IsLeaf()) 
        {
                //cout << "pt: " << point[node->mAxis] << " " << node->mPosition << endl;
                if (point[node->mAxis] < node->mPosition)
                        node = node->mBack;
                else
                        node = node->mFront;
        }

        //cout << "vc: " << node->mViewCell->GetBox() << " pvs " << node->mViewCell->mPvs.Size() << endl;

        return node->mViewCell;
}


bool ViewCellsTree::LoadFromFile(const std::string &filename, float scaleFactor)
{
        cout << "Loading view cells from file '" + filename + "'";

        FILE *fr = fopen(filename.c_str(), "rb");

        if (!fr) 
        {
                cerr << "Error: Cannot open file for reading" << endl;
                return false;
        }

        bool result = _LoadFromFile(fr, scaleFactor);

        cout << "finished loading view cells. " << endl;
        fclose(fr);

        return result;
}


bool ViewCellsTree::_LoadFromFile(FILE *fr, float scaleFactor)
{
        int buffer[256]; 
        fread(buffer, sizeof(int), 2, fr);

        if (buffer[0] != MAGIC) 
        {
                cerr << "Error: Wrong file type" << endl;
                return false;
        }

        if (buffer[1] != (int)(1000 * VIEWCELLS_VERSION)) 
        {
                cerr << "Error: Wrong viewcells version" << endl;
                return false;
        }

        AxisAlignedBox3 box;
        // get the bounding box
        // exchange x and y coordinates and recompute box
        fread(&box, sizeof(AxisAlignedBox3), 1, fr);

        box.Scale(scaleFactor);

        Vector3 v1(box.Min().x, -box.Min().z, box.Min().y);
        Vector3 v2(box.Max().x, -box.Max().z, box.Max().y);
        
        mBox.Initialize();

        mBox.Include(v1);
        mBox.Include(v2);

        stack<ViewCellsTreeNode **> nodeStack;
        nodeStack.push(&mRoot);

        cout << "view cells bounds " << mBox << endl;

        int numViewCells = 0;

        int axes[] = {0, 0, 0};

        while (!nodeStack.empty()) 
        {
                ViewCellsTreeNode *&node = *nodeStack.top();
                nodeStack.pop();
                node = new ViewCellsTreeNode();

                ++ numViewCells;

                int axis;
                fread(&axis, sizeof(int), 1, fr);

                // exchange y and z axis like for whole scene
                if (axis == 2) axis = 1;
                else if (axis == 1) axis = 2;

                node->mAxis = axis;

                if (!node->IsLeaf())
                {
                        ++ axes[node->mAxis];

                        float mypos;
                        fread(&mypos, sizeof(float), 1, fr);

                        mypos *= scaleFactor;

                        // changed coordinate system must be considered also here
                        if (node->mAxis == 1) 
                        {
                                node->mPosition = -mypos;

                                nodeStack.push(&node->mBack);
                                nodeStack.push(&node->mFront);
                                //cout << mypos << " ";
                        }
                        else
                        {
                                node->mPosition = mypos;
                                
                                nodeStack.push(&node->mFront);
                                nodeStack.push(&node->mBack);
                        }
                }
        }

        return true;
}



}