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;
}
