Merge 4ee73b5f86 into 3a069427cd

src/db/db/dbPLC.cc

@@ -110,6 +110,17 @@ Vertex::is_outside () const
   return false;
 }
 
+bool
+Vertex::is_on_outline () const
+{
+  for (auto e = mp_edges.begin (); e != mp_edges.end (); ++e) {
+    if ((*e)->is_segment ()) {
+      return true;
+    }
+  }
+  return false;
+}
+
 void
 Vertex::set_is_precious (bool f, unsigned int id)
 {

src/db/db/dbPLC.h

@@ -96,6 +96,11 @@ public:
    */
   bool is_outside () const;
 
+  /**
+   *  @brief Gets a value indicating whether is on the outline - i.e. one edge is a segment
+   */
+  bool is_on_outline () const;
+
   /**
    *  @brief Gets a list of polygons that are attached to this vertex
    */

src/db/db/dbPLCConvexDecomposition.cc

@@ -31,6 +31,8 @@
 #include <vector>
 #include <map>
 
+// #define DEBUG_DUMP_ESSENTIAL_EDGES
+
 namespace db
 {
 
@@ -286,16 +288,23 @@ ConvexDecomposition::hertel_mehlhorn_decomposition (Triangulation &tris, const C
   //  them one-by-one, but using them in length order, from the
 
   std::unordered_set<const Edge *> essential_edges;
+  std::unordered_set<const Vertex *> concave_vertexes_seen;
+
+  while (! concave_vertexes.empty ()) {
 
     typedef std::list<std::pair<double, const Edge *> > angles_and_edges_list;
     angles_and_edges_list angles_and_edges;
     std::vector<angles_and_edges_list::iterator> sorted_edges;
 
+    std::unordered_set<const Vertex *> new_inner_vertexes;
+
     for (auto cc = concave_vertexes.begin (); cc != concave_vertexes.end (); ++cc) {
 
       angles_and_edges.clear ();
       const Vertex *v0 = cc->corner;
 
+      concave_vertexes_seen.insert (v0);
+
       const Edge *e = cc->incoming;
       while (e) {
 
@@ -340,11 +349,73 @@ ConvexDecomposition::hertel_mehlhorn_decomposition (Triangulation &tris, const C
       for (auto i = angles_and_edges.begin (); i != angles_and_edges.end (); ++i) {
         if (i->second) {
           essential_edges.insert (i->second);
+          //  record new endpoints of essential edges which are inside the polygon - i.e. they
+          //  have a segment attached. Below we will turn them into new concave "corners" and
+          //  continue deriving essential edges from there.
+          if (! i->second->v1 ()->is_on_outline () && concave_vertexes_seen.find (i->second->v1 ()) == concave_vertexes_seen.end ()) {
+            new_inner_vertexes.insert (i->second->v1 ());
+          }
+          if (! i->second->v2 ()->is_on_outline () && concave_vertexes_seen.find (i->second->v2 ()) == concave_vertexes_seen.end ()) {
+            new_inner_vertexes.insert (i->second->v2 ());
+          }
         }
       }
 
     }
 
+    //  new inner vertexes (i.e. endpoints of essential edges inside the polygon) are treated as new convex vertexes
+
+    concave_vertexes.clear ();
+
+    for (auto i = new_inner_vertexes.begin (); i != new_inner_vertexes.end (); ++i) {
+
+      const Vertex *v0 = *i;
+      auto ie = v0->begin_edges ();
+      for ( ; ie != v0->end_edges () && essential_edges.find (*ie) == essential_edges.end (); ++ie)
+        ;
+      tl_assert (ie != v0->end_edges ());
+      const Edge *e = *ie;
+
+      const Edge *en = e;
+
+      do {
+
+        const Edge *enn = en;
+
+        //  look for the next edge (clockwise) which is an essential edge
+        do {
+          const Polygon *t = enn->v2 () == v0 ? enn->right () : enn->left ();
+          tl_assert (t != 0);
+          enn = t->next_edge (enn, v0);
+          tl_assert (enn != 0);
+        } while (enn != en && essential_edges.find (enn) == essential_edges.end ());
+
+        db::DEdge e1 (*en->other (v0), *v0);
+        db::DEdge e2 (*v0, *enn->other (v0));
+
+        //  vp > 0: concave, vp < 0: convex
+        int vp_sign = db::vprod_sign (e1, e2);
+        if (vp_sign > 0 || en == enn /*folding back*/) {
+          concave_vertexes.push_back (ConcaveCorner (v0, en, enn));
+        }
+
+        en = enn;
+
+      } while (en != e);
+    }
+
+  }
+
+#if defined(DEBUG_DUMP_ESSENTIAL_EDGES)
+  //  dump the essential edges for debugging
+  db::Edges edges;
+  for (auto e = essential_edges.begin (); e != essential_edges.end (); ++e) {
+    db::DEdge de = (*e)->edge ();
+    edges.insert (db::VCplxTrans (1000.0) * de);
+  }
+  edges.write ("debug_dump_essential_edges.gds");
+#endif
+
   //  Combine triangles, but don't cross essential edges
 
   std::unordered_set<const Polygon *> left_triangles;

src/db/db/dbPLCConvexDecomposition.h

@@ -136,14 +136,14 @@ private:
       //  .. nothing yet ..
     }
 
-    ConcaveCorner (Vertex *_corner, Edge *_incoming, Edge *_outgoing)
+    ConcaveCorner (const Vertex *_corner, const Edge *_incoming, const Edge *_outgoing)
       : corner (_corner), incoming (_incoming), outgoing (_outgoing)
     {
       //  .. nothing yet ..
     }
 
-    Vertex *corner;
-    Edge *incoming, *outgoing;
+    const Vertex *corner;
+    const Edge *incoming, *outgoing;
   };
 
   void hertel_mehlhorn_decomposition (Triangulation &tris, const ConvexDecompositionParameters &param);

src/db/unit_tests/dbPLCConvexDecompositionTests.cc

@@ -23,6 +23,8 @@
 
 #include "dbPLCConvexDecomposition.h"
 #include "dbWriter.h"
+#include "dbReader.h"
+#include "dbLayout.h"
 #include "dbRegionProcessors.h"
 #include "dbTestSupport.h"
 #include "tlUnitTest.h"
@@ -144,3 +146,80 @@ TEST(problematic_polygon)
   db::compare_layouts (_this, *ly, tl::testdata () + "/algo/hm_decomposition_au5.gds");
 }
 
+TEST(problematic_polygon2)
+{
+  db::Point contour[] = {
+    db::Point (-2100, 200),
+    db::Point (-2100, 2000),
+    db::Point (-500, 2000),
+    db::Point (-500, 1700),
+    db::Point (-849, 1700),
+    db::Point (-947, 1690),
+    db::Point (-1043, 1671),
+    db::Point (-1137, 1643),
+    db::Point (-1228, 1605),
+    db::Point (-1315, 1559),
+    db::Point (-1396, 1504),
+    db::Point (-1472, 1442),
+    db::Point (-1542, 1372),
+    db::Point (-1604, 1296),
+    db::Point (-1659, 1215),
+    db::Point (-1705, 1128),
+    db::Point (-1743, 1037),
+    db::Point (-1771, 943),
+    db::Point (-1790, 847),
+    db::Point (-1800, 749),
+    db::Point (-1800, 200)
+  };
+
+  db::Polygon poly;
+  poly.assign_hull (contour + 0, contour + sizeof (contour) / sizeof (contour[0]));
+
+  double dbu = 0.001;
+
+  db::plc::ConvexDecompositionParameters param;
+  param.with_segments = false;
+  param.split_edges = false;
+  param.tri_param.max_area = 1000000;
+  param.tri_param.min_b = 0.5;
+
+  db::plc::Graph plc;
+  TestableConvexDecomposition decomp (&plc);
+
+  decomp.decompose (poly, param, dbu);
+
+  std::unique_ptr<db::Layout> ly (plc.to_layout ());
+  db::compare_layouts (_this, *ly, tl::testdata () + "/algo/hm_decomposition_au6.gds");
+}
+
+TEST(polygon_with_holes)
+{
+  db::Layout ly;
+  tl::InputStream s (tl::testdata () + "/algo/hm_decomposition_7.gds");
+  db::Reader reader (s);
+  reader.read (ly);
+
+  unsigned int l1 = ly.get_layer (db::LayerProperties (1, 0));
+  const db::Cell &top = ly.cell (*ly.begin_top_down ());
+
+  db::Region r (db::RecursiveShapeIterator (ly, top, l1));
+  r.merge ();
+  db::Polygon poly = *r.begin ();
+
+  double dbu = 0.001;
+
+  db::plc::ConvexDecompositionParameters param;
+  param.with_segments = false;
+  param.split_edges = false;
+  param.tri_param.max_area = 1000000;
+  param.tri_param.min_b = 0.5;
+
+  db::plc::Graph plc;
+  TestableConvexDecomposition decomp (&plc);
+
+  decomp.decompose (poly, param, dbu);
+
+  std::unique_ptr<db::Layout> ly_out (plc.to_layout ());
+  db::compare_layouts (_this, *ly_out, tl::testdata () + "/algo/hm_decomposition_au7.gds");
+}
+