osg::Node* Graticule::createGridLevel( unsigned int levelNum ) const { if ( !_map->isGeocentric() ) { OE_WARN << "Graticule: only supports geocentric maps" << std::endl; return 0L; } Graticule::Level level; if ( !getLevel( levelNum, level ) ) return 0L; OE_DEBUG << "Graticule: creating grid level " << levelNum << std::endl; osg::Group* group = new osg::Group(); const Profile* mapProfile = _map->getProfile(); const GeoExtent& pex = mapProfile->getExtent(); double tw = pex.width() / (double)level._cellsX; double th = pex.height() / (double)level._cellsY; for( unsigned int x=0; x<level._cellsX; ++x ) { for( unsigned int y=0; y<level._cellsY; ++y ) { GeoExtent tex( mapProfile->getSRS(), pex.xMin() + tw * (double)x, pex.yMin() + th * (double)y, pex.xMin() + tw * (double)(x+1), pex.yMin() + th * (double)(y+1) ); double ox = level._lineWidth; double oy = level._lineWidth; Geometry* geom = createCellGeometry( tex, level._lineWidth, pex, _map->isGeocentric() ); Feature* feature = new Feature(); feature->setGeometry( geom ); FeatureList features; features.push_back( feature ); FilterContext cx; cx.profile() = new FeatureProfile( tex ); cx.isGeocentric() = _map->isGeocentric(); if ( _map->isGeocentric() ) { // We need to make sure that on a round globe, the points are sampled such that // long segments follow the curvature of the earth. ResampleFilter resample; resample.maxLength() = tex.width() / 10.0; resample.perturbationThreshold() = level._lineWidth/1000.0; cx = resample.push( features, cx ); } TransformFilter xform( mapProfile->getSRS() ); xform.setMakeGeocentric( _map->isGeocentric() ); cx = xform.push( features, cx ); Bounds bounds = feature->getGeometry()->getBounds(); double exDist = bounds.radius()/2.0; osg::Node* cellVolume = createVolume( feature->getGeometry(), -exDist, exDist*2, cx ); osg::Node* child = cellVolume; if ( cx.hasReferenceFrame() ) { osg::MatrixTransform* xform = new osg::MatrixTransform( cx.inverseReferenceFrame() ); xform->addChild( child ); // the transform matrix here does NOT include a rotation, so we need to get the normal // for the cull plane callback. osg::Vec3d normal = xform->getBound().center(); xform->setCullCallback( new CullPlaneCallback( normal ) ); child = xform; } group->addChild( child ); } } // organize it for better culling osgUtil::Optimizer opt; opt.optimize( group, osgUtil::Optimizer::SPATIALIZE_GROUPS ); osg::Node* result = group; if ( levelNum+1 < getNumLevels() ) { Graticule::Level nextLevel; if ( getLevel( levelNum+1, nextLevel ) ) { osg::PagedLOD* plod = new osg::PagedLOD(); plod->addChild( group, nextLevel._maxRange, level._maxRange ); std::stringstream buf; buf << levelNum+1 << "_" << getID() << "." << GRID_MARKER << "." << GRATICLE_EXTENSION; std::string bufStr = buf.str(); plod->setFileName( 1, bufStr ); plod->setRange( 1, 0, nextLevel._maxRange ); result = plod; } } return result; }