OpenSceneGraph/src/osgPlugins/txp/TXPArchive.cpp

#include <osg/Notify>
#include <osg/Geode>
#include <osg/ShapeDrawable>
#include <osg/AlphaFunc>
#include <osg/Group>
#include <osg/Image>
#include <osg/Texture2D>
#include <osg/Material>
#include <osg/TexEnv>
#include <osg/CullFace>
#include <osg/Light>
#include <osg/StateSet>
#include <osg/Point>
#include <osg/BlendFunc>
#include <osg/MatrixTransform>
#include <osgDB/FileUtils>
#include <osgDB/FileUtils>
#include <osgDB/FileNameUtils>
#include <osgDB/ReadFile>
#include <osgDB/WriteFile>
#include <osgSim/Sector>
#include <osgSim/LightPoint>
#include <osgSim/LightPointNode>
#include <osgSim/BlinkSequence>
#include <iostream>
#include <fstream>

#if defined(linux)
#  include <unistd.h>
#  define _access access
#endif

#include "TXPArchive.h"
#include "TXPParser.h"
#include "TileMapper.h"

#include <OpenThreads/ScopedLock>

using namespace txp;

#define TXPArchiveERROR(s) osg::notify(osg::NOTICE) << "txp::TXPArchive::" << (s) << " error: "


void TXPArchive::SetTexMap(int key,osg::ref_ptr<osg::Texture2D> ref)
{
    _texmap[key] = ref;
}

osg::ref_ptr<osg::Texture2D> TXPArchive::GetTexMapEntry(int key)
{
    return _texmap[key];
}

void TXPArchive::SetStatesMap(int key,osg::ref_ptr<osg::StateSet> ref)
{
    _statesMap[key] = ref;
}

osg::ref_ptr<osg::StateSet> TXPArchive::GetStatesMapEntry(int key)
{
    return _statesMap[key];
}

TXPArchive::TXPArchive():
    trpgr_Archive(),
    _id(-1),
    _numLODs(0),
    _swExtents(0.0,0.0),
    _neExtents(0.0,0.0),
    _majorVersion(-1),
    _minorVersion(-1),
    _isMaster(false),
    _loadMaterialsToStateSet(false)
{
}

TXPArchive::~TXPArchive()
{
    CloseFile();
}


void  TXPArchive::getExtents(osg::BoundingBox& extents)
{
    TileInfo sw, ne;
    trpg2iPoint tileExtents;

    this->GetHeader()->GetLodSize(0, tileExtents);
    this->getTileInfo(0, 0, 0, sw);
    this->getTileInfo(tileExtents.x-1, tileExtents.y-1, 0, ne);
    extents.set(sw.bbox._min, sw.bbox._max);
    extents.expandBy(ne.bbox);
}
    

bool TXPArchive::openFile(const std::string& archiveName)
{
    std::string path = osgDB::getFilePath(archiveName);
    std::string name = osgDB::getSimpleFileName(archiveName);
    
    if(path.empty())
    {
        SetDirectory(".");
    }
    else
    {
        // push the path to the front of the list so that all subsequenct
        // files get loaded relative to this if possible.
        osgDB::getDataFilePathList().push_front(path);
        SetDirectory(path.c_str());
    }
    
    if (!OpenFile(name.c_str()))
    {
        TXPArchiveERROR("openFile()") << "couldn't open archive: " << archiveName << std::endl;
        return false;
    }

    if (!ReadHeader(false))
    {
        TXPArchiveERROR("openFile()") << "couldn't read header for archive: " << archiveName << std::endl;
        return false;
    }

    const trpgHeader *header = GetHeader();
    if (header)
    {
        header->GetNumLods(_numLODs);
        header->GetExtents(_swExtents,_neExtents);
        header->GetVersion(_majorVersion, _minorVersion);
    _isMaster = header->GetIsMaster();
    }

    int numTextures;
    texTable.GetNumTextures(numTextures);

    int numModel;
    modelTable.GetNumModels(numModel);
    _models.clear();

    int numMaterials;
    materialTable.GetNumMaterial(numMaterials);

    return true;
}

bool TXPArchive::loadMaterial(int ix)
{
    int i = ix;


    if (GetStatesMapEntry(ix).get())
    return true;

    osg::StateSet* osg_state_set = new osg::StateSet;
            
    const trpgMaterial *mat;
    mat = materialTable.GetMaterialRef(0,i);

    // Set texture
    int numMatTex;
    mat->GetNumTexture(numMatTex);
    
    // TODO : multitextuting
    // also note that multitexturing in terrapage can came from two sides
    // - multiple textures per material, and multiple materials per geometry
    // Note: Only in theory.  The only type you'll encounter is multiple
    //         materials per polygon.
    if( numMatTex )
    {
        osg::Material *osg_material     = new osg::Material;
        
        float64 alpha;
        mat->GetAlpha(alpha);
        
        trpgColor color;
        mat->GetAmbient(color);
        osg_material->setAmbient( osg::Material::FRONT_AND_BACK , 
                  osg::Vec4(color.red, color.green, color.blue, alpha));
        mat->GetDiffuse(color);
        osg_material->setDiffuse(osg::Material::FRONT_AND_BACK , 
                 osg::Vec4(color.red, color.green, color.blue, alpha));
        
        mat->GetSpecular(color);
        osg_material->setSpecular(osg::Material::FRONT_AND_BACK , 
                  osg::Vec4(color.red, color.green, color.blue, alpha));
        mat->GetEmission(color);
        osg_material->setEmission(osg::Material::FRONT_AND_BACK , 
                  osg::Vec4(color.red, color.green, color.blue, alpha));

        float64 shinines;
        mat->GetShininess(shinines);
        osg_material->setShininess(osg::Material::FRONT_AND_BACK , (float)shinines);
        
        osg_material->setAlpha(osg::Material::FRONT_AND_BACK ,(float)alpha);
        osg_state_set->setAttributeAndModes(osg_material, osg::StateAttribute::ON);
        
        SetUserDataToMaterialAttributes(*osg_state_set, *mat);

        if( alpha < 1.0f )
        {
            osg_state_set->setMode(GL_BLEND,osg::StateAttribute::ON);
            osg_state_set->setRenderingHint(osg::StateSet::TRANSPARENT_BIN);
        }
        
        int alphaFunc;
        mat->GetAlphaFunc(alphaFunc);
        if( alphaFunc>=GL_NEVER && alphaFunc<=GL_ALWAYS)
        {
            float64 ref;
            mat->GetAlphaRef(ref);
            osg::AlphaFunc *osg_alpha_func = new osg::AlphaFunc;
            osg_alpha_func->setFunction((osg::AlphaFunc::ComparisonFunction)alphaFunc,(float)ref);
            osg_state_set->setAttributeAndModes(osg_alpha_func, osg::StateAttribute::ON);
        }
        
        for (int ntex = 0; ntex < numMatTex; ntex ++ )
        {
            int texId;
            trpgTextureEnv texEnv;
            mat->GetTexture(ntex,texId,texEnv);
        
            // Set up texture environment
            osg::TexEnv       *osg_texenv       = new osg::TexEnv();
            int32 te_mode;
            texEnv.GetEnvMode(te_mode);
            switch( te_mode )
            {
            case trpgTextureEnv::Alpha :
                osg_texenv->setMode(osg::TexEnv::REPLACE);
                break;
            case trpgTextureEnv::Decal:
                osg_texenv->setMode(osg::TexEnv::DECAL);
                break;
            case trpgTextureEnv::Blend :
                osg_texenv->setMode(osg::TexEnv::BLEND);
                break;
            case trpgTextureEnv::Modulate :
                osg_texenv->setMode(osg::TexEnv::MODULATE);
                break;
            }
        
            osg_state_set->setTextureAttribute(ntex,osg_texenv);

            int wrap_s, wrap_t;   
            texEnv.GetWrap(wrap_s, wrap_t);

            loadTexture(texId);
            osg::Texture2D* osg_texture = GetTexMapEntry(texId).get();
            if(osg_texture)
            {

                osg_texture->setWrap(osg::Texture2D::WRAP_S, wrap_s == trpgTextureEnv::Repeat ? osg::Texture2D::REPEAT: osg::Texture2D::CLAMP_TO_EDGE );
                osg_texture->setWrap(osg::Texture2D::WRAP_T, wrap_t == trpgTextureEnv::Repeat ? osg::Texture2D::REPEAT: osg::Texture2D::CLAMP_TO_EDGE );

                // -----------
                // Min filter
                // -----------
                int32 minFilter;
                texEnv.GetMinFilter(minFilter);
                switch (minFilter)
                {
                case trpgTextureEnv::Point:
                case trpgTextureEnv::Nearest:
                    osg_texture->setFilter(osg::Texture2D::MIN_FILTER, osg::Texture2D::NEAREST);
                    break;
                case trpgTextureEnv::Linear:
                    osg_texture->setFilter(osg::Texture2D::MIN_FILTER, osg::Texture2D::LINEAR);
                    break;
                case trpgTextureEnv::MipmapPoint:
                    osg_texture->setFilter(osg::Texture2D::MIN_FILTER, osg::Texture2D::NEAREST_MIPMAP_NEAREST);
                    break;
                case trpgTextureEnv::MipmapLinear:
                    osg_texture->setFilter(osg::Texture2D::MIN_FILTER, osg::Texture2D::NEAREST_MIPMAP_LINEAR);
                    break;
                case trpgTextureEnv::MipmapBilinear:
                    osg_texture->setFilter(osg::Texture2D::MIN_FILTER, osg::Texture2D::LINEAR_MIPMAP_NEAREST);
                    break;
                case trpgTextureEnv::MipmapTrilinear:
                    osg_texture->setFilter(osg::Texture2D::MIN_FILTER, osg::Texture2D::LINEAR_MIPMAP_LINEAR);
                    break;
                default:
                    osg_texture->setFilter(osg::Texture2D::MIN_FILTER, osg::Texture2D::LINEAR);
                    break;
                }


                // -----------
                // Mag filter
                // -----------
                int32 magFilter;
                texEnv.GetMagFilter(magFilter);
                switch (magFilter)
                {
                case trpgTextureEnv::Point:
                case trpgTextureEnv::Nearest:
                    osg_texture->setFilter(osg::Texture2D::MAG_FILTER,osg::Texture2D::NEAREST);
                    break;
                case trpgTextureEnv::Linear:
                default:
                    osg_texture->setFilter(osg::Texture2D::MAG_FILTER, osg::Texture2D::LINEAR);
                    break;
                }

                // pass on to the stateset.                
                osg_state_set->setTextureAttributeAndModes(ntex,osg_texture, osg::StateAttribute::ON);

                if(osg_texture->getImage() &&  osg_texture->getImage()->isImageTranslucent())
                { 
                    osg_state_set->setMode(GL_BLEND,osg::StateAttribute::ON);
                    osg_state_set->setRenderingHint(osg::StateSet::TRANSPARENT_BIN);
                }
            }        
        }
        
        int cullMode;
        mat->GetCullMode(cullMode);
        
        // Culling mode in txp means opposite from osg i.e. Front-> show front face
        if( cullMode != trpgMaterial::FrontAndBack)
        {
            osg::CullFace* cull_face = new osg::CullFace;
            switch (cullMode)
            {
            case trpgMaterial::Front:
                cull_face->setMode(osg::CullFace::BACK);
                break;
            case trpgMaterial::Back:
                cull_face->setMode(osg::CullFace::FRONT);
                break;
            }
            osg_state_set->setAttributeAndModes(cull_face, osg::StateAttribute::ON);
        }
    }
    SetStatesMap(i,osg_state_set);

    return true;
}

bool TXPArchive::loadMaterials()
{
    return true;
}

bool TXPArchive::loadTexture(int i)
{
    if (GetTexMapEntry(i).get())
    return true;        
        
    bool separateGeo = false;
    int majorVer,minorVer;
    GetVersion(majorVer,minorVer);
    if((majorVer >= TRPG_NOMERGE_VERSION_MAJOR) && (minorVer>=TRPG_NOMERGE_VERSION_MINOR))
    {
    separateGeo = true;
    }
    trpgrImageHelper image_helper(this->GetEndian(),getDir(),materialTable,texTable,separateGeo);

    const trpgTexture *tex;
    tex = texTable.GetTextureRef(i);
    if (!tex) 
    return false;

    trpgTexture::ImageMode mode;
    tex->GetImageMode(mode);
    if(mode == trpgTexture::External)
    {
    char texName[ 1024 ];
    texName[ 0 ] = 0;
        tex->GetName(texName,1023);

        // Create a texture by name.
        osg::ref_ptr<osg::Texture2D> osg_texture = new osg::Texture2D();

        // make sure the Texture unref's the Image after apply, when it is no longer needed.                
        osg_texture->setUnRefImageDataAfterApply(true);
        
        // Load Texture and Create Texture State
        std::string filename = osgDB::getSimpleFileName(texName);
        std::string path(getDir());
#ifdef _WIN32
        const char _PATHD = '\\';
#elif defined(macintosh)
        const char _PATHD = ':';
#else
        const char _PATHD = '/';
#endif
        if( path == "." ) 
            path = "";
        else
            path += _PATHD ;
        
        std::string theFile = path + filename ;
        osg::Image* image = osgDB::readImageFile(theFile);
        if (image)
        {
            osg_texture->setImage(image);
        }
        else
        {
            osg::notify(osg::WARN) << "TrPageArchive::LoadMaterials() error: "
                   << "couldn't open image: " << filename << std::endl;
        }
    SetTexMap(i,osg_texture);
    }
    else if( mode == trpgTexture::Local )
    {
    SetTexMap(i,getLocalTexture(image_helper,tex));
    }
    else if( mode == trpgTexture::Template )
    {
    SetTexMap(i,0L);
    }
    else
    {
    SetTexMap(i,0L);
    }

    return (GetTexMapEntry(i).get() != 0);
}

bool TXPArchive::loadModel(int ix)
{
    trpgModel *mod = modelTable.GetModelRef(ix);
    int type;
    if(!mod)
    return false;
    mod->GetType(type);

    // Only dealing with external models currently
    if (type == trpgModel::External)
    {
        char name[1024];
        mod->GetName(name,1023);

        // Load the model.  It's probably not TerraPage
    osg::Node *osg_model = osgDB::readNodeFile( name );
    if ( !osg_model )
        {
            osg::notify(osg::WARN) << "TrPageArchive::LoadModels() error: "
                   << "failed to load model: "
                   << name << std::endl;
        }
    // Do this even if it's NULL
    _models[ ix ] = osg_model;
    }
/*
  else
  {
  trpgMemReadBuffer buf(GetEndian());
  mod->Read(buf);
  Group *osg_model = parse->ParseScene(buf, m_gstates , m_models);
  m_models.push_back(osg_model);  
  }
*/
    return true;
}

bool TXPArchive::loadModels()
{
    osg::notify(osg::NOTICE) << "txp:: Loading models ..." << std::endl;

    int numModel;
    modelTable.GetNumModels(numModel);

    // use a pointer to the models map to bootstrap our map
    trpgModelTable::ModelMapType *mt = modelTable.GetModelMap();
    trpgModelTable::ModelMapType::iterator itr = mt->begin();
    for (  ; itr != mt->end( ); itr++)
    {
    loadModel(itr->first);
    }
    osg::notify(osg::NOTICE) << "txp:: ... done." << std::endl;
    return true;
}

bool TXPArchive::loadLightAttributes()
{
    osg::notify(osg::NOTICE) << "txp:: Loading light attributes ..." << std::endl;

    trpgLightTable::LightMapType *lm  = lightTable.getLightMap();
    trpgLightTable::LightMapType::iterator itr = lm->begin();
    for ( ; itr != lm->end() ; itr++)
    {
        trpgLightAttr* ref = &itr->second;

        osgSim::LightPointNode* osgLight = new osgSim::LightPointNode();

        osg::Point* osgPoint = new osg::Point();

        osgSim::LightPoint lp ;
        lp._on = true;

        trpgColor col;
        ref->GetFrontColor(col);
        lp._color = osg::Vec4(col.red, col.green,col.blue, 1.0);

        float64 inten;
        ref->GetFrontIntensity(inten);
        lp._intensity = inten;

        trpgLightAttr::PerformerAttr perfAttr;
        ref->GetPerformerAttr(perfAttr);

        // point part
        //osgPoint->setSize(perfAttr.actualSize);
        osgPoint->setSize(5);
        osgPoint->setMaxSize(perfAttr.maxPixelSize);
        osgPoint->setMinSize(perfAttr.minPixelSize);    
        osgPoint->setFadeThresholdSize(perfAttr.transparentFallofExp);
        //numbers that are going to appear are "experimental"
        osgPoint->setDistanceAttenuation(osg::Vec3(0.0001, 0.0005, 0.00000025));
//        osgPoint->setDistanceAttenuation(osg::Vec3(1.0, 0.0, 1.0));

        osg::StateSet* stateSet = new osg::StateSet();
        stateSet->setMode(GL_LIGHTING, osg::StateAttribute::OFF);
        stateSet->setMode(GL_POINT_SMOOTH, osg::StateAttribute::ON);
        stateSet->setAttributeAndModes(osgPoint, osg::StateAttribute::ON );
        stateSet->setAttributeAndModes(new osg::BlendFunc, osg::StateAttribute::ON);

        osgLight->setMaxPixelSize(perfAttr.maxPixelSize);
        osgLight->setMinPixelSize(perfAttr.minPixelSize);    

//        float64 clamp;
//        ref->GetPerformerTpClamp(clamp);
//        osgLight->setMaxVisibleDistance2(clamp);

        trpg3dPoint normal;
        ref->GetNormal(normal);

//        lp._radius = clamp;

        trpgLightAttr::LightDirectionality direc;
        ref->GetDirectionality(direc);
        if( direc == trpgLightAttr::trpg_Unidirectional)
        {
            osgSim::AzimElevationSector*  sec = new osgSim::AzimElevationSector();
            float64 tmp;
            ref->GetHLobeAngle(tmp);
            float64 tmpfade;
            ref->GetLobeFalloff(tmpfade);
            sec->setAzimuthRange(-tmp/2.0,tmp/2.0,tmpfade);

            ref->GetVLobeAngle(tmp);
            sec->setElevationRange(0,tmp, tmpfade);

            lp._sector = sec;
            osgLight->addLightPoint(lp);
        }
        else if( direc == trpgLightAttr::trpg_Bidirectional )
        {
            osgSim::AzimElevationSector*  front = new osgSim::AzimElevationSector();
            float64 tmp;
            ref->GetHLobeAngle(tmp);
            float64 tmpfade;
            ref->GetLobeFalloff(tmpfade);
            front->setAzimuthRange(-tmp/2.0,tmp/2.0,tmpfade);

            ref->GetVLobeAngle(tmp);
            front->setElevationRange(0,tmp, tmpfade);

            lp._sector = front;
            osgLight->addLightPoint(lp);

            osgSim::AzimElevationSector*  back = new osgSim::AzimElevationSector();
            back->setAzimuthRange(osg::PI-tmp/2.0,osg::PI+tmp/2.0,tmpfade);
            back->setElevationRange(0,tmp, tmpfade);
            lp._sector = back;
            osgLight->addLightPoint(lp);
        } 
    else
    {
            osgLight->addLightPoint(lp);
        }

    addLightAttribute(osgLight, stateSet, osg::Vec3(normal.x,normal.y,normal.z),itr->first);
    }

    osg::notify(osg::NOTICE) << "txp:: ... done." << std::endl;
    return true;
}

void trim(std::string& str)
{
    while (!str.empty() && isspace(str[str.length()-1]))
    str.erase(str.length()-1);
    while (!str.empty() && isspace(str[0]))
        str.erase(0,1);
}
bool TXPArchive::loadTextStyles()
{
    const trpgTextStyleTable *textStyleTable = GetTextStyleTable();
    if ( !textStyleTable )
    return false;
    if ( textStyleTable->GetNumStyle() < 1 )
    return true;

    // try fontmap.txt
    std::map< std::string, std::string > fontmap;

    std::string fmapfname = std::string(getDir())+"\\fontmap.txt";
    std::ifstream fmapfile;
    fmapfile.open(fmapfname.c_str(),std::ios::in);

    if (fmapfile.is_open())
    {
    osg::notify(osg::NOTICE) << "txp:: Font map file found: " << fmapfname << std::endl;
    std::string line;
    while (std::getline(fmapfile,line))
    {
        std::string::size_type ix = line.find_first_of('=');
        if (ix != std::string::npos)
        {
        std::string fontname = line.substr(0,ix);
        std::string fontfilename = line.substr(ix+1,line.length()-ix+1);

        trim(fontname);
        trim(fontfilename);

        fontmap[fontname] = fontfilename;

        }
    }
    fmapfile.close();
    }
    else
    {
    osg::notify(osg::NOTICE) << "txp:: No font map file found: " << fmapfname << std::endl;        
    osg::notify(osg::NOTICE) << "txp:: All fonts defaulted to arial.ttf" << std::endl;        
    }

    const trpgTextStyleTable::StyleMapType *smap = textStyleTable->getStyleMap();
    trpgTextStyleTable::StyleMapType::const_iterator itr = smap->begin();
    for (  ; itr != smap->end(); itr++)
    {
    const trpgTextStyle *textStyle = &itr->second; 
    if ( !textStyle )
        continue;

    const std::string *fontName = textStyle->GetFont();
    if ( !fontName )
        continue;

    std::string fontfilename = fontmap[*fontName];
    if ( !fontfilename.length() )
        fontfilename = "arial.ttf";
    osg::ref_ptr< osgText::Font > font = osgText::readFontFile(fontfilename);

    _fonts[itr->first] = font;

    const trpgMatTable* matTable = GetMaterialTable();
    if (matTable)
    {
        int matId = textStyle->GetMaterial();
        const trpgMaterial* mat = matTable->GetMaterialRef(0,matId);
        if (mat)
        {
        trpgColor faceColor;
        mat->GetColor(faceColor);

        float64 alpha;
        mat->GetAlpha(alpha);

        _fcolors[itr->first] = osg::Vec4(faceColor.red, faceColor.green, faceColor.blue, alpha );
        }
    }
    }

    return true;
}

void TXPArchive::addLightAttribute(osgSim::LightPointNode* lpn, osg::StateSet* fallback, const osg::Vec3& att,int handle)
{
    DeferredLightAttribute la;
    la.lightPoint = lpn;
    la.fallback = fallback;
    la.attitude = att;
    _lights[handle] = la;
}

bool TXPArchive::getTileInfo(const TileLocationInfo& loc, TileInfo& info)
{
    info.minRange = 0.0;
    info.maxRange = 0.0;
    info.radius = 0.f;
    info.center.set(0.f,0.f,0.f);
    info.bbox.set(0.f,0.f,0.f,0.f,0.f,0.f);

    OpenThreads::ScopedLock<OpenThreads::Mutex> lock(_mutex);

    header.GetLodRange(loc.lod,info.maxRange);
    header.GetLodRange(loc.lod+1,info.minRange);
    header.GetLodRange(0,info.lod0Range);

    trpg2dPoint sw,ne;
    header.GetExtents(sw,ne);

    trpg2dPoint size;
    header.GetTileSize(loc.lod,size);

    info.size.x() = size.x;
    info.size.y() = size.y;
    info.size.z() = 0.f;

    info.center.set(
        sw.x+(loc.x*size.x)+(size.x/2.f),
        sw.y+(loc.y*size.y)+(size.y/2.f),
        (loc.zmin + loc.zmax)/2.f
    );
    info.bbox.set(
        osg::Vec3(
            info.center.x()-(size.x/2.f),
            info.center.y()-(size.y/2.f),
            loc.zmin
        ),
        osg::Vec3(
            info.center.x()+(size.x/2.f),
            info.center.y()+(size.y/2.f),
            loc.zmax
        )
    );
    info.radius = osg::Vec3(size.x/2.f, size.y/2.f,0.f).length() * 1.3;

    return true;
   
}

bool TXPArchive::getTileInfo(int x, int y, int lod, TileInfo& info)
{
   
    if(_majorVersion == 2 && _minorVersion >=1)
    {
    // Version 2.1
    // Tile table contain only lod 0
    if(lod > 0)
        return false;
    }

    trpgwAppAddress addr;
    float minz = 0.f;
    float maxz = 0.f;
    tileTable.GetTile(x, y, lod, addr, minz, maxz);

    TileLocationInfo loc(x, y, lod, addr,  minz, maxz);

    return getTileInfo(loc, info);
}

osg::Group* TXPArchive::getTileContent(
    int x, int y, int lod,
    double realMinRange, 
    double realMaxRange, 
    double usedMaxRange,
    osg::Vec3& tileCenter,
    std::vector<TileLocationInfo>& childInfoList)
{
    if(_majorVersion == 2 && _minorVersion >= 1)
    {
    // Version 2.1
    // This call is valid only for lod = 0
    if(lod != 0)
        return new osg::Group;
    }

    trpgwAppAddress addr;
    float minz = 0.f;
    float maxz = 0.f;
    tileTable.GetTile(x, y, lod, addr, minz, maxz);
    TileLocationInfo loc(x,y,lod,addr, minz,maxz);

    return getTileContent(loc, realMinRange, realMaxRange, usedMaxRange, tileCenter, childInfoList);

}

class ModelVisitor : public osg::NodeVisitor
{
    TXPArchive* _archive;
    TXPArchive::TileLocationInfo _tileInfo;
//     int _x;
//     int _y;
//     int _lod;

public:
    ModelVisitor(TXPArchive* archive, const TXPArchive::TileLocationInfo& loc):
        osg::NodeVisitor(osg::NodeVisitor::TRAVERSE_ALL_CHILDREN),
        _archive(archive), _tileInfo(loc)
    {
    }
    
    virtual void apply(osg::MatrixTransform& xform)
    {
        const trpgHeader* header = _archive->GetHeader();
        trpgHeader::trpgTileType tileType;
        header->GetTileOriginType(tileType);
        const osg::Referenced* ref = xform.getUserData();
        const TileIdentifier* tileID = dynamic_cast<const txp::TileIdentifier*>(ref);

        if(!tileID) return; // bail early - this isn't a loaded model

        if(tileType == trpgHeader::TileLocal && tileID->lod == 9999)
        {
        trpg2dPoint tileExtents;
        header->GetTileSize(0, tileExtents);
        osg::BoundingBox bbox;
        _archive->getExtents(bbox);
        osg::Vec3 offset(xform.getMatrix().getTrans());
        offset[0] -= bbox._min[0];
        offset[1] -= bbox._min[1];

        trpg2dPoint offsetXY, tileID(_tileInfo.x,_tileInfo.y);
        int divider = (0x01 << _tileInfo.lod);
        // calculate which tile model is located in
        tileExtents.x /= divider;
        tileExtents.y /= divider;
        offset[0] -= tileID.x*tileExtents.x;
        offset[1] -= tileID.y*tileExtents.y;

        osg::Matrix mat(xform.getMatrix());
        mat.setTrans(offset);
        xform.setMatrix(mat);
        }
    }
};


osg::Group* TXPArchive::getTileContent(
    const TileLocationInfo& loc,
    double realMinRange, 
    double realMaxRange, 
    double usedMaxRange,
    osg::Vec3& tileCenter,
    std::vector<TileLocationInfo>& childInfoList)
{

    if (_parser.get() == 0) 
    {
        _parser = new TXPParser();
        _parser->setArchive(this);
    }

    trpgMemReadBuffer buf(GetEndian());
    bool readStatus;
    trpgTileTable::TileMode tileMode;
    tileTable.GetMode(tileMode);
    if(tileMode == trpgTileTable::External)
    readStatus = ReadExternalTile(loc.x, loc.y, loc.lod, buf);
    else
    readStatus = ReadTile(loc.addr, buf);

    if(!readStatus)
    return new osg::Group;
    trpgTileHeader *tilehdr = _parser->getTileHeaderRef();

    int majVersion,minVersion;
    GetVersion(majVersion,minVersion);
    // only compute block # if we are a master archive.
    if((majVersion >= TRPG_NOMERGE_VERSION_MAJOR) && (minVersion >= TRPG_NOMERGE_VERSION_MINOR) && (_isMaster))
    {
    if(tilehdr)
    {
        int x,y;
        unsigned int denom = (1 << loc.lod); // this should work up to lod 31
        x = loc.x/denom;
        y = loc.y/denom;
        tilehdr->SetBlockNo(y,x);
    }
    }

    osg::Group *tileGroup = _parser->parseScene(buf,_statesMap,_models,realMinRange,realMaxRange,usedMaxRange);
    tileCenter = _parser->getTileCenter();

    int nbChild = _parser->GetNbChildrenRef();
    
    childInfoList.clear();
    for(int idx = 0; idx < nbChild; idx++)
    {
    const trpgChildRef *childRef = _parser->GetChildRef(idx);
       
    if(childRef)
    {
        TileLocationInfo loc;
        childRef->GetTileLoc(loc.x, loc.y, loc.lod);
        childRef->GetTileZValue(loc.zmin, loc.zmax);
        childRef->GetTileAddress(loc.addr);
        childInfoList.push_back(loc);

    }
    }

    // Fix up model MatrixTransform
    ModelVisitor mv(this, loc);
    tileGroup->accept(mv);

    // Prune
    OSGStatesMapType::iterator itr = _statesMap.begin();
    while( itr != _statesMap.end( ) )
    {
    if(itr->second.valid() &&
       (itr->second->referenceCount()==1))
    {
        // unreference it.
            itr->second = NULL;
            
            OSGStatesMapType::iterator toRemove = itr;
            ++itr;
            
        // remove it from the map
            _statesMap.erase( toRemove );
        }
        else
        {
            ++itr;
        }
    }

    OSGTexMapType::iterator mitr = _texmap.begin();
    while( mitr != _texmap.end( ) )
    {
    if(mitr->second.valid() &&
       (mitr->second->referenceCount()==1))
    {
        // unreference it.
            mitr->second = NULL;
            
            OSGTexMapType::iterator toRemove = mitr;
            ++mitr;
            
        // remove it from the map
            _texmap.erase( toRemove );
    }
        else
        {
            ++mitr;
        }
    }

    return tileGroup;
}

bool TXPArchive::getLODSize(int lod, int& x, int& y)
{
    x = y = 0;

    OpenThreads::ScopedLock<OpenThreads::Mutex> lock(_mutex);

    trpg2iPoint size;
    if (header.GetLodSize(lod,size))
    {
        x = size.x;
        y = size.y;
    }
    
    return true;
}