void
TessellateOperator::tessellateLinear( const osg::Vec3d& p0, const osg::Vec3d& p1, unsigned parts, Vec3dVector& out )
{
osg::Vec3d vec = (p1-p0)/double(parts);
out.push_back( p0 );
for( unsigned i=1; i<parts; ++i )
{
out.push_back( p0 + vec*double(i) );
}
}
void
TessellateOperator::operator()( Feature* feature, FilterContext& context ) const
{
if (_numPartitions <= 1 ||
!feature ||
!feature->getGeometry() ||
feature->getGeometry()->getComponentType() == Geometry::TYPE_POINTSET )
{
return;
}
bool isGeo = context.profile() ? context.profile()->getSRS()->isGeographic() : true;
GeoInterpolation interp = feature->geoInterp().isSet() ? *feature->geoInterp() : _defaultInterp;
GeometryIterator i( feature->getGeometry(), true );
while( i.hasMore() )
{
Geometry* g = i.next();
bool isRing = dynamic_cast<Ring*>( g ) != 0L;
Vec3dVector newVerts;
newVerts.reserve( g->size() * _numPartitions );
for( Geometry::const_iterator v = g->begin(); v != g->end(); ++v )
{
const osg::Vec3d& p0 = *v;
if ( v != g->end()-1 ) // not last vert
{
if ( isGeo )
tessellateGeo( *v, *(v+1), _numPartitions, interp, newVerts );
else
tessellateLinear( *v, *(v+1), _numPartitions, newVerts );
}
else if ( isRing )
{
if ( isGeo )
tessellateGeo( *v, *g->begin(), _numPartitions, interp, newVerts );
else
tessellateLinear( *v, *g->begin(), _numPartitions, newVerts );
}
else
{
// get the final vert.
newVerts.push_back( *v );
}
}
g->swap( newVerts );
}
}
void
TessellateOperator::tessellateGeo( const osg::Vec3d& p0, const osg::Vec3d& p1, unsigned parts, GeoInterpolation interp, Vec3dVector& out )
{
double step = 1.0/double(parts);
double zdelta = p1.z() - p0.z();
out.push_back( p0 );
for( unsigned i=1; i<parts; ++i )
{
double t = step*double(i);
osg::Vec3d p;
if ( interp == GEOINTERP_GREAT_CIRCLE )
{
double lat, lon;
GeoMath::interpolate(
osg::DegreesToRadians(p0.y()), osg::DegreesToRadians(p0.x()),
osg::DegreesToRadians(p1.y()), osg::DegreesToRadians(p1.x()),
t,
lat, lon );
p.set( osg::RadiansToDegrees(lon), osg::RadiansToDegrees(lat), p0.z() + t*zdelta );
}
else // GEOINTERP_RHUMB_LINE
{
double lat1 = osg::DegreesToRadians(p0.y()), lon1 = osg::DegreesToRadians(p0.x());
double lat2 = osg::DegreesToRadians(p1.y()), lon2 = osg::DegreesToRadians(p1.x());
double totalDistance = GeoMath::rhumbDistance( lat1, lon1, lat2, lon2 );
double bearing = GeoMath::rhumbBearing( lat1, lon1, lat2, lon2 );
double interpDistance = t * totalDistance;
double lat3, lon3;
GeoMath::rhumbDestination(lat1, lon1, bearing, interpDistance, lat3, lon3);
p.set( osg::RadiansToDegrees(lon3), osg::RadiansToDegrees(lat3), p0.z() + t*zdelta );
}
out.push_back(p);
}
}
void
TessellateOperator::operator()( Feature* feature, FilterContext& context ) const
{
if (_numPartitions <= 1 ||
!feature ||
!feature->getGeometry() ||
feature->getGeometry()->getComponentType() == Geometry::TYPE_POINTSET )
{
return;
}
Units featureUnits = feature->getSRS() ? feature->getSRS()->getUnits() : Units::METERS;
bool isGeo = feature->getSRS() ? feature->getSRS()->isGeographic() : false;
GeoInterpolation geoInterp = feature->geoInterp().isSet() ? *feature->geoInterp() : _defaultInterp;
double sliceSize = 0.0;
int numPartitions = _numPartitions;
if ( _maxDistance.isSet() )
{
// copmpute the slice size in feature units.
double latitude = feature->getGeometry()->getBounds().center().y();
sliceSize = SpatialReference::transformUnits( _maxDistance.value(), feature->getSRS(), latitude );
sliceSize = _maxDistance->as(Units::METERS);
}
GeometryIterator i( feature->getGeometry(), true );
while( i.hasMore() )
{
Geometry* g = i.next();
bool isRing = dynamic_cast<Ring*>( g ) != 0L;
Vec3dVector newVerts;
for( Geometry::const_iterator v = g->begin(); v != g->end(); ++v )
{
unsigned slices = _numPartitions;
const osg::Vec3d& p0 = *v;
if ( v != g->end()-1 ) // not last vert
{
// calculate slice count
if ( sliceSize > 0.0 )
{
double dist = GeoMath::distance(*v, *(v + 1), feature->getSRS());
slices = std::max( 1u, (unsigned)(dist / sliceSize) );
}
if ( isGeo )
tessellateGeo( *v, *(v+1), slices, geoInterp, newVerts );
else
tessellateLinear( *v, *(v+1), slices, newVerts );
}
else if ( isRing )
{
// calculate slice count
if ( sliceSize > 0.0 )
{
double dist = GeoMath::distance(*v, *g->begin(), feature->getSRS());
slices = std::max( 1u, (unsigned)(dist / sliceSize) );
}
if ( isGeo )
tessellateGeo( *v, *g->begin(), slices, geoInterp, newVerts );
else
tessellateLinear( *v, *g->begin(), slices, newVerts );
}
else
{
// get the final vert.
newVerts.push_back( *v );
}
}
g->swap( newVerts );
}
}
