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-rw-r--r--src/CGAL_Nef_polyhedron.cc2
-rw-r--r--src/cgalutils.cc27
-rw-r--r--src/cgalutils.h5
-rw-r--r--src/dxftess-cgal.cc119
4 files changed, 127 insertions, 26 deletions
diff --git a/src/CGAL_Nef_polyhedron.cc b/src/CGAL_Nef_polyhedron.cc
index 2d5bba5..8b54eba 100644
--- a/src/CGAL_Nef_polyhedron.cc
+++ b/src/CGAL_Nef_polyhedron.cc
@@ -100,7 +100,7 @@ PolySet *CGAL_Nef_polyhedron::convertToPolyset()
ps = new PolySet();
CGAL_Polyhedron P;
this->p3->convert_to_Polyhedron(P);
- bool err = createPolySetFromPolyhedron(P, ps);
+ bool err = createPolySetFromPolyhedron(P, *ps);
if (err) delete ps;
}
catch (const CGAL::Precondition_exception &e) {
diff --git a/src/cgalutils.cc b/src/cgalutils.cc
index bb46f1c..12e743d 100644
--- a/src/cgalutils.cc
+++ b/src/cgalutils.cc
@@ -8,10 +8,9 @@
#include <map>
-PolySet *createPolySetFromPolyhedron(const CGAL_Polyhedron &p)
+bool createPolySetFromPolyhedron(const CGAL_Polyhedron &p, PolySet &ps)
{
- PolySet *ps = new PolySet();
-
+ bool err = false;
typedef CGAL_Polyhedron::Vertex Vertex;
typedef CGAL_Polyhedron::Vertex_const_iterator VCI;
typedef CGAL_Polyhedron::Facet_const_iterator FCI;
@@ -35,13 +34,13 @@ PolySet *createPolySetFromPolyhedron(const CGAL_Polyhedron &p)
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);
+ 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;
+ return err;
}
#undef GEN_SURFACE_DEBUG
@@ -127,22 +126,20 @@ public:
}
};
-CGAL_Polyhedron *createPolyhedronFromPolySet(const PolySet &ps)
+bool createPolyhedronFromPolySet(const PolySet &ps, CGAL_Polyhedron &p)
{
- CGAL_Polyhedron *P = NULL;
+ bool err = false;
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);
+ p.delegate(builder);
}
catch (const CGAL::Assertion_exception &e) {
PRINTB("CGAL error in CGAL_Build_PolySet: %s", e.what());
- delete P;
- P = NULL;
+ err = true;
}
CGAL::set_error_behaviour(old_behaviour);
- return P;
+ return err;
}
CGAL_Iso_cuboid_3 bounding_box( const CGAL_Nef_polyhedron3 &N )
diff --git a/src/cgalutils.h b/src/cgalutils.h
index 0e7fbb5..8f7e4dd 100644
--- a/src/cgalutils.h
+++ b/src/cgalutils.h
@@ -2,8 +2,9 @@
#define CGALUTILS_H_
#include <cgal.h>
-bool createPolySetFromPolyhedron(const CGAL_Polyhedron &p, class PolySet &ps);
-bool createPolyhedronFromPolySet(const class PolySet &ps, CGAL_Polyhedron &p);
+#include "polyset.h"
+bool createPolySetFromPolyhedron(const CGAL_Polyhedron &p, PolySet &ps);
+bool createPolyhedronFromPolySet(const PolySet &ps, CGAL_Polyhedron &p);
CGAL_Iso_cuboid_3 bounding_box( const CGAL_Nef_polyhedron3 &N );
CGAL_Iso_rectangle_2e bounding_box( const CGAL_Nef_polyhedron2 &N );
diff --git a/src/dxftess-cgal.cc b/src/dxftess-cgal.cc
index d6f592f..6899598 100644
--- a/src/dxftess-cgal.cc
+++ b/src/dxftess-cgal.cc
@@ -336,19 +336,122 @@ void dxf_tesselate(PolySet *ps, DxfData &dxf, double rot, Vector2d scale, bool u
}
}
-void triangulate_polygon( const PolySet::Polygon &pgon, std::vector<PolySet::Polygon> &triangles )
-{
+typedef enum { XYPLANE, YZPLANE, XZPLANE, NONE } projection_t;
+
+Vector2d get_projected_point( Vector3d v, projection_t projection ) {
+ Vector2d v2(0,0);
+ if (projection==XYPLANE) { v2.x() = v.x(); v2.y() = v.y(); }
+ else if (projection==XZPLANE) { v2.x() = v.x(); v2.y() = v.z(); }
+ else if (projection==YZPLANE) { v2.x() = v.y(); v2.y() = v.z(); }
+ return v2;
+}
+CGAL_Point_3 cgp( Vector3d v ) { return CGAL_Point_3( v.x(), v.y(), v.z() ); }
+/* near-planar polygons in 3d can be projected into 2d, but you have to
+be careful. if you project, say, 0,0,0 0,1,0 0,1,1 0,0,1 onto the XY plane
+you will not get a polygon, you will get a skinny line thing. */
+projection_t find_good_projection( PolySet::Polygon pgon ) {
+ // step 1 - find 3 non-collinear points in the input
+ if (pgon.size()<3) return NONE;
+ Vector3d v1,v2,v3;
+ v1 = v2 = v3 = pgon[0];
+ for (size_t i=0;i<pgon.size();i++) {
+ if (pgon[i]!=v1) { v2=pgon[i]; break; }
+ }
+ if (v1==v2) return NONE;
+ for (size_t i=0;i<pgon.size();i++) {
+ if (!CGAL::collinear( cgp(v1), cgp(v2), cgp(pgon[i]) )) {
+ v3=pgon[i]; break;
+ }
+ }
+ if (CGAL::collinear( cgp(v1), cgp(v2), cgp(v3) ) ) return NONE;
+ // step 2 - find which direction is best for projection. planes use
+ // the equation ax+by+cz+d = 0. a,b, and c determine the direction the
+ // plane is in. we want to find which projection of the 'normal vector'
+ // would make the smallest shadow if projected onto the given plane.
+ // 'quadrance' (distance squared) can tell this w/o using sqrt.
+ CGAL::Plane_3<CGAL_Kernel3> pl( cgp(v1), cgp(v2), cgp(v3) );
+ NT3 qxy = pl.a()*pl.a()+pl.b()*pl.b();
+ NT3 qyz = pl.b()*pl.b()+pl.c()*pl.c();
+ NT3 qxz = pl.c()*pl.c()+pl.a()*pl.a();
+ NT3 min = std::min(qxy,std::min(qyz,qxz));
+ if (min==qxy) return XYPLANE;
+ else if (min==qyz) return YZPLANE;
+ return XZPLANE;
}
-/* given a 3d PolySet with 'near planar' faces, triangulate the faces
-so CGAL Nef Polyhedron will accept them. */
+void triangulate_polygon( const PolySet::Polygon &pgon, std::vector<PolySet::Polygon> &triangles, projection_t projection )
+{
+ CDT cdt;
+ std::vector<Vertex_handle> vhandles;
+ std::map<CDTPoint,Vector3d> vertmap;
+ CGAL::Orientation original_orientation;
+ std::vector<CDTPoint> orpgon;
+ for (size_t i = 0; i < pgon.size(); i++) {
+ Vector3d v3 = pgon.at(i);
+ Vector2d v2 = get_projected_point( v3, projection );
+ CDTPoint cdtpoint = CDTPoint(v2.x(),v2.y());
+ vertmap[ cdtpoint ] = v3;
+ Vertex_handle vh = cdt.insert( cdtpoint );
+ vhandles.push_back(vh);
+ orpgon.push_back( cdtpoint );
+ }
+ original_orientation = CGAL::orientation_2( orpgon.begin(),orpgon.end() );
+ for (size_t i = 0; i < vhandles.size(); i++ ) {
+ int vindex1 = (i+0);
+ int vindex2 = (i+1)%vhandles.size();
+ cdt.insert_constraint( vhandles[vindex1], vhandles[vindex2] );
+ }
+ std::list<CDTPoint> list_of_seeds;
+ CGAL::refine_Delaunay_mesh_2_without_edge_refinement(cdt,
+ list_of_seeds.begin(), list_of_seeds.end(), DummyCriteria<CDT>());
+
+ CDT::Finite_faces_iterator fit;
+ for( fit=cdt.finite_faces_begin(); fit!=cdt.finite_faces_end(); fit++ )
+ {
+ if(fit->is_in_domain()) {
+ CDTPoint p1 = cdt.triangle( fit )[0];
+ CDTPoint p2 = cdt.triangle( fit )[1];
+ CDTPoint p3 = cdt.triangle( fit )[2];
+ Vector3d v1 = vertmap[p1];
+ Vector3d v2 = vertmap[p2];
+ Vector3d v3 = vertmap[p3];
+ PolySet::Polygon pgon;
+ if (CGAL::orientation(p1,p2,p3)==original_orientation) {
+ pgon.push_back(v1);
+ pgon.push_back(v2);
+ pgon.push_back(v3);
+ } else {
+ pgon.push_back(v3);
+ pgon.push_back(v2);
+ pgon.push_back(v1);
+ }
+ triangles.push_back( pgon );
+ }
+ }
+}
+
+/* given a 3d PolySet with 'near planar' faces, triangulate the faces.
+See Issue 340... this is so CGAL Nef Polyhedron will accept them.
+This code assumes the input polyset has simple polygon faces with no holes. */
void tessellate_3d_faces( const PolySet &inps, PolySet &outps ) {
+ PRINTB("tess 3d %i",inps.polygons.size());
+ PRINTB("%s < input ps",inps.dump());
for (size_t i = 0; i < inps.polygons.size(); i++) {
- const PolySet::Polygon *pgon = &inps.polygons[i];
- for (size_t j = 0; j < pgon->size(); j++) {
- Vector3d v = pgon->at(j);
- }
+ const PolySet::Polygon pgon = inps.polygons[i];
+ if (pgon.size()<3) continue;
+ std::vector<PolySet::Polygon> triangles;
+ projection_t projection = find_good_projection( pgon );
+ triangulate_polygon( pgon, triangles, projection );
+ for (size_t j=0;j<triangles.size();j++) {
+ PolySet::Polygon t = triangles[j];
+ outps.append_poly();
+ outps.append_vertex(t[0].x(),t[0].y(),t[0].z());
+ outps.append_vertex(t[1].x(),t[1].y(),t[1].z());
+ outps.append_vertex(t[2].x(),t[2].y(),t[2].z());
+ }
}
+ PRINTB("tess 3d done %i",outps.polygons.size());
+ PRINTB("%s < output ps",outps.dump());
}
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