openscad/src/cgalutils.cc

#ifdef ENABLE_CGAL

#include "cgalutils.h"
#include "polyset.h"
#include "printutils.h"

#include "cgal.h"
#include <CGAL/assertions_behaviour.h>
#include <CGAL/exceptions.h>

PolySet *createPolySetFromPolyhedron(const CGAL_Polyhedron &p)
{
	PolySet *ps = new PolySet();
		
	typedef CGAL_Polyhedron::Vertex                                 Vertex;
	typedef CGAL_Polyhedron::Vertex_const_iterator                  VCI;
	typedef CGAL_Polyhedron::Facet_const_iterator                   FCI;
	typedef CGAL_Polyhedron::Halfedge_around_facet_const_circulator HFCC;
		
	for (FCI fi = p.facets_begin(); fi != p.facets_end(); ++fi) {
		HFCC hc = fi->facet_begin();
		HFCC hc_end = hc;
		Vertex v1, v2, v3;
		v1 = *VCI((hc++)->vertex());
		v3 = *VCI((hc++)->vertex());
		do {
			v2 = v3;
			v3 = *VCI((hc++)->vertex());
			double x1 = CGAL::to_double(v1.point().x());
			double y1 = CGAL::to_double(v1.point().y());
			double z1 = CGAL::to_double(v1.point().z());
			double x2 = CGAL::to_double(v2.point().x());
			double y2 = CGAL::to_double(v2.point().y());
			double z2 = CGAL::to_double(v2.point().z());
			double x3 = CGAL::to_double(v3.point().x());
			double y3 = CGAL::to_double(v3.point().y());
			double z3 = CGAL::to_double(v3.point().z());
			ps->append_poly();
			ps->append_vertex(x1, y1, z1);
			ps->append_vertex(x2, y2, z2);
			ps->append_vertex(x3, y3, z3);
		} while (hc != hc_end);
	}
	return ps;
}

#undef GEN_SURFACE_DEBUG

class CGAL_Build_PolySet : public CGAL::Modifier_base<CGAL_HDS>
{
public:
	typedef CGAL_HDS::Vertex::Point CGALPoint;

	const PolySet &ps;
	CGAL_Build_PolySet(const PolySet &ps) : ps(ps) { }

	void operator()(CGAL_HDS& hds)
	{
		CGAL_Polybuilder B(hds, true);

		std::vector<CGALPoint> vertices;
		Grid3d<int> vertices_idx(GRID_FINE);

		for (size_t i = 0; i < ps.polygons.size(); i++) {
			const PolySet::Polygon *poly = &ps.polygons[i];
			for (size_t j = 0; j < poly->size(); j++) {
				const Vector3d &p = poly->at(j);
				if (!vertices_idx.has(p[0], p[1], p[2])) {
					vertices_idx.data(p[0], p[1], p[2]) = vertices.size();
					vertices.push_back(CGALPoint(p[0], p[1], p[2]));
				}
			}
		}

		B.begin_surface(vertices.size(), ps.polygons.size());
#ifdef GEN_SURFACE_DEBUG
		printf("=== CGAL Surface ===\n");
#endif

		for (size_t i = 0; i < vertices.size(); i++) {
			const CGALPoint &p = vertices[i];
			B.add_vertex(p);
#ifdef GEN_SURFACE_DEBUG
			printf("%d: %f %f %f\n", i, p[0], p[1], p[2]);
#endif
		}

		for (size_t i = 0; i < ps.polygons.size(); i++) {
			const PolySet::Polygon *poly = &ps.polygons[i];
			QHash<int,int> fc;
			bool facet_is_degenerated = false;
			for (size_t j = 0; j < poly->size(); j++) {
				const Vector3d &p = poly->at(j);
				int v = vertices_idx.data(p[0], p[1], p[2]);
				if (fc[v]++ > 0)
					facet_is_degenerated = true;
			}
			
			if (!facet_is_degenerated)
				B.begin_facet();
#ifdef GEN_SURFACE_DEBUG
			printf("F:");
#endif
			for (size_t j = 0; j < poly->size(); j++) {
				const Vector3d &p = poly->at(j);
#ifdef GEN_SURFACE_DEBUG
				printf(" %d (%f,%f,%f)", vertices_idx.data(p[0], p[1], p[2]), p[0], p[1], p[2]);
#endif
				if (!facet_is_degenerated)
					B.add_vertex_to_facet(vertices_idx.data(p[0], p[1], p[2]));
			}
#ifdef GEN_SURFACE_DEBUG
			if (facet_is_degenerated)
				printf(" (degenerated)");
			printf("\n");
#endif
			if (!facet_is_degenerated)
				B.end_facet();
		}

#ifdef GEN_SURFACE_DEBUG
		printf("====================\n");
#endif
		B.end_surface();

		#undef PointKey
	}
};

CGAL_Polyhedron *createPolyhedronFromPolySet(const PolySet &ps)
{
	CGAL_Polyhedron *P = NULL;
	CGAL::Failure_behaviour old_behaviour = CGAL::set_error_behaviour(CGAL::THROW_EXCEPTION);
	try {
		P = new CGAL_Polyhedron;
		CGAL_Build_PolySet builder(ps);
		P->delegate(builder);
	}
	catch (CGAL::Assertion_exception e) {
		PRINTF("CGAL error in CGAL_Build_PolySet: %s", e.what());
		CGAL::set_error_behaviour(old_behaviour);
	}
	return P;
}

#endif /* ENABLE_CGAL */