examples/alphashapes/alphashapes3d.hpp
author Dmitriy Morozov <dmitriy@mrzv.org>
Tue, 05 Apr 2011 18:29:50 -0700
branchdev
changeset 242 a06b4b515476
parent 179 d15c6d144645
child 272 29306411272b
permissions -rw-r--r--
alphashapes2d can handle degenerate inputs (thanks to Taras Galkovskyi for the bug report and the fix)

#include <utilities/log.h>
#include <boost/foreach.hpp>

AlphaSimplex3D::	    
AlphaSimplex3D(const Delaunay3D::Vertex& v): alpha_(0), attached_(false)
{
	for (int i = 0; i < 4; ++i)
		if (v.cell()->vertex(i)->point() == v.point())
			Parent::add(v.cell()->vertex(i));
}

AlphaSimplex3D::	    
AlphaSimplex3D(const Delaunay3D::Edge& e)
{
    Cell_handle c = e.first;
	Parent::add(c->vertex(e.second));
	Parent::add(c->vertex(e.third));
}

AlphaSimplex3D::	    
AlphaSimplex3D(const Delaunay3D::Edge& e, const SimplexSet& simplices, const Delaunay3D& Dt, Facet_circulator facet_bg)
{
    Cell_handle c = e.first;
	Parent::add(c->vertex(e.second));
	Parent::add(c->vertex(e.third));

	Facet_circulator cur = facet_bg;
	while (Dt.is_infinite(*cur))    ++cur; 
	SimplexSet::const_iterator cur_iter = simplices.find(AlphaSimplex3D(*cur));
	RealValue min = cur_iter->alpha();
	
    const VertexSet& vertices = static_cast<const Parent*>(this)->vertices();
	VertexSet::const_iterator v = vertices.begin();
	const Point& p1 = (*v++)->point();
	const Point& p2 = (*v)->point();
	attached_ = false;

	if (facet_bg != 0) do
	{
		VertexSet::const_iterator v = vertices.begin();
		int i0 = (*cur).first->index(*v++);
		int i1 = (*cur).first->index(*v);
		int i = 6 - i0 - i1 - (*cur).second;
        if (Dt.is_infinite(cur->first->vertex(i))) { ++cur; continue; }
		Point p3 = (*cur).first->vertex(i)->point();

		cur_iter = simplices.find(AlphaSimplex3D(*cur));
		if (CGAL::side_of_bounded_sphere(p1, p2, p3) == CGAL::ON_BOUNDED_SIDE)
			attached_ = true;
		RealValue val = cur_iter->alpha();
		if (val < min)
			min = val;
		++cur;
	} while (cur != facet_bg);

	if (attached_)
		alpha_ = min;
	else
		alpha_ = CGAL::squared_radius(p1, p2);
}

AlphaSimplex3D::	    
AlphaSimplex3D(const Delaunay3D::Facet& f)
{
    Cell_handle c = f.first;
	for (int i = 0; i < 4; ++i)
		if (i != f.second)
			Parent::add(c->vertex(i));
}

AlphaSimplex3D::	    
AlphaSimplex3D(const Delaunay3D::Facet& f, const SimplexSet& simplices, const Delaunay3D& Dt)
{
    Cell_handle c = f.first;
	for (int i = 0; i < 4; ++i)
		if (i != f.second)
			Parent::add(c->vertex(i));

	Cell_handle o = c->neighbor(f.second);
	int oi = o->index(c);

	VertexSet::const_iterator v = static_cast<const Parent*>(this)->vertices().begin();
	const Point& p1 = (*v++)->point();
	const Point& p2 = (*v++)->point();
	const Point& p3 = (*v)->point();
	
	attached_ = false;
	if (!Dt.is_infinite(c->vertex(f.second)) && 
        CGAL::side_of_bounded_sphere(p1, p2, p3,
									 c->vertex(f.second)->point()) == CGAL::ON_BOUNDED_SIDE)
		attached_ = true;
	else if (!Dt.is_infinite(o->vertex(oi)) &&
             CGAL::side_of_bounded_sphere(p1, p2, p3,
										  o->vertex(oi)->point()) == CGAL::ON_BOUNDED_SIDE)
		attached_ = true;
	else
		alpha_ = squared_radius(p1, p2, p3);
	
	if (attached_)
	{
		if (Dt.is_infinite(c))
			alpha_ = simplices.find(AlphaSimplex3D(*o))->alpha();
		else if (Dt.is_infinite(o))
			alpha_ = simplices.find(AlphaSimplex3D(*c))->alpha();
		else
			alpha_ = std::min(simplices.find(AlphaSimplex3D(*c))->alpha(), 
                              simplices.find(AlphaSimplex3D(*o))->alpha());
	}
}

AlphaSimplex3D::	    
AlphaSimplex3D(const Delaunay3D::Cell& c): attached_(false)
{
	for (int i = 0; i < 4; ++i)
		Parent::add(c.vertex(i));
	VertexSet::const_iterator v = static_cast<const Parent*>(this)->vertices().begin();
	Point p1 = (*v++)->point();
	Point p2 = (*v++)->point();
	Point p3 = (*v++)->point();
	Point p4 = (*v)->point();
	alpha_ = CGAL::squared_radius(p1, p2, p3, p4);
}


bool 
AlphaSimplex3D::AlphaOrder::
operator()(const AlphaSimplex3D& first, const AlphaSimplex3D& second) const
{
	if (first.alpha() == second.alpha())
		return (first.dimension() < second.dimension());
	else
		return (first.alpha() < second.alpha()); 
}

std::ostream& 
AlphaSimplex3D::
operator<<(std::ostream& out) const
{
	for (VertexSet::const_iterator cur = Parent::vertices().begin(); cur != Parent::vertices().end(); ++cur)
		out << **cur << ", ";
	out << "value = " << value();

	return out;
}

void fill_simplex_set(const Delaunay3D& Dt, AlphaSimplex3D::SimplexSet& simplices)
{
	// Compute all simplices with their alpha values and attachment information
	for(Cell_iterator cur = Dt.finite_cells_begin(); cur != Dt.finite_cells_end(); ++cur)
		simplices.insert(AlphaSimplex3D(*cur));
	rInfo("Cells inserted");
	for(Facet_iterator cur = Dt.finite_facets_begin(); cur != Dt.finite_facets_end(); ++cur)
		simplices.insert(AlphaSimplex3D(*cur, simplices, Dt));
	rInfo("Facets inserted");
	for(Edge_iterator cur = Dt.finite_edges_begin(); cur != Dt.finite_edges_end(); ++cur)
		simplices.insert(AlphaSimplex3D(*cur, simplices, Dt, Dt.incident_facets(*cur)));
	rInfo("Edges inserted");
	for(Vertex_iterator cur = Dt.finite_vertices_begin(); cur != Dt.finite_vertices_end(); ++cur)
		simplices.insert(AlphaSimplex3D(*cur));
	rInfo("Vertices inserted");
}

template<class Filtration>
void fill_complex(const Delaunay3D& Dt, Filtration& filtration)
{
	AlphaSimplex3D::SimplexSet simplices;
    fill_simplex_set(Dt, simplices);
    BOOST_FOREACH(const AlphaSimplex3D& s, simplices)
        filtration.push_back(s);
}