/**
* intersection post processing
*/
void post_intersection( const GeometrySet<2>& input, GeometrySet<2>& output )
{
//
// reverse orientation of polygons if needed
for ( GeometrySet<2>::SurfaceCollection::const_iterator it = input.surfaces().begin();
it != input.surfaces().end();
++it ) {
const CGAL::Polygon_with_holes_2<Kernel>& p = it->primitive();
CGAL::Polygon_2<Kernel> outer = p.outer_boundary();
if ( outer.orientation() == CGAL::CLOCKWISE ) {
outer.reverse_orientation();
}
std::list<CGAL::Polygon_2<Kernel> > rings;
for ( CGAL::Polygon_with_holes_2<Kernel>::Hole_const_iterator hit = p.holes_begin();
hit != p.holes_end();
++hit ) {
rings.push_back( *hit );
if ( hit->orientation() == CGAL::COUNTERCLOCKWISE ) {
rings.back().reverse_orientation();
}
}
output.surfaces().push_back( CGAL::Polygon_with_holes_2<Kernel>( outer, rings.begin(), rings.end() ) );
}
output.points() = input.points();
output.segments() = input.segments();
output.volumes() = input.volumes();
}
// pa and pb intersects
static void difference_primitive( const PrimitiveHandle<Dim>& pa, const PrimitiveHandle<Dim>& pb, GeometrySet<Dim>& output )
{
if ( pa.handle.which() == PrimitivePoint ) {
// difference = empty
}
else if ( pa.handle.which() == PrimitiveSegment ) {
GeometrySet<Dim> inter;
algorithm::intersection( pa, pb, inter );
if ( ! inter.segments().empty() ) {
for ( typename GeometrySet<Dim>::SegmentCollection::const_iterator it = inter.segments().begin();
it != inter.segments().end();
++it ) {
PrimitiveHandle<Dim> p( &it->primitive() );
substract_from_segment( pa, p, output );
}
}
else {
output.addPrimitive( pa );
}
}
}
static void filter_self_intersection( const GeometrySet<Dim>& input, GeometrySet<Dim>& output )
{
{
typedef std::list< CollectionElement<typename Point_d<Dim>::Type> > PointList;
PointList points;
std::copy( input.points().begin(), input.points().end(), std::back_inserter( points ) );
typename PointList::iterator it = points.begin();
while ( it != points.end() ) {
bool intersectsA = false;
for ( typename PointList::iterator it2 = points.begin(); it2 != points.end(); ++it2 ) {
if ( it == it2 ) {
continue;
}
PrimitiveHandle<Dim> pa1( &it->primitive() );
PrimitiveHandle<Dim> pa2( &it2->primitive() );
if ( CGAL::do_overlap( it->primitive().bbox(), it2->primitive().bbox() ) &&
algorithm::intersects( pa1, pa2 ) ) {
intersectsA = true;
GeometrySet<Dim> temp;
algorithm::intersection( pa1, pa2, temp );
std::copy( temp.points().begin(), temp.points().end(), std::back_inserter( points ) );
// erase it2
points.erase( it2 );
break;
}
}
if ( ! intersectsA ) {
output.addPrimitive( it->primitive() );
}
// suppress A
it = points.erase( it );
}
}
{
typedef std::list< CollectionElement<typename Segment_d<Dim>::Type> > SegmentList;
SegmentList segments;
std::copy( input.segments().begin(), input.segments().end(), std::back_inserter( segments ) );
typename SegmentList::iterator it = segments.begin();
while ( it != segments.end() ) {
bool intersectsA = false;
for ( typename SegmentList::iterator it2 = segments.begin(); it2 != segments.end(); ++it2 ) {
if ( it == it2 ) {
continue;
}
PrimitiveHandle<Dim> pa1( &it->primitive() );
PrimitiveHandle<Dim> pa2( &it2->primitive() );
if ( CGAL::do_overlap( it->primitive().bbox(), it2->primitive().bbox() ) &&
algorithm::intersects( pa1, pa2 ) ) {
intersectsA = true;
GeometrySet<Dim> temp;
algorithm::intersection( pa1, pa2, temp );
std::copy( temp.segments().begin(), temp.segments().end(), std::back_inserter( segments ) );
// erase it2
segments.erase( it2 );
break;
}
}
if ( ! intersectsA ) {
output.addPrimitive( it->primitive() );
}
// suppress A
it = segments.erase( it );
}
}
}