Test whether a new point would encroach segments by inserting it!

This replaces the old way which didn't work correctly, which was based
on visibility checks inside the input PSLG of the CDT

diff --git a/poly2tri-c/refine/delaunay-terminator.c b/poly2tri-c/refine/delaunay-terminator.c
index 97043534900fda2514fb14f3a082ec4a90b1169f..88e2274c5721dd36967ad150e0b8bdae9e646860 100644 (file)
--- a/poly2tri-c/refine/delaunay-terminator.c
+++ b/poly2tri-c/refine/delaunay-terminator.c
@@ -82,26 +82,32 @@ p2tr_cdt_is_encroached_by (P2trCDT     *self,
 }
 
 
-P2trHashSet*
-p2tr_cdt_get_segments_encroached_by (P2trCDT     *self,
-                                     P2trVector2 *C)
+P2trVEdgeSet*
+p2tr_cdt_get_segments_encroached_by (P2trCDT   *self,
+                                     P2trPoint *v)
 {
-  P2trHashSet *encroached_edges = p2tr_hash_set_new (g_direct_hash,
-      g_direct_equal, (GDestroyNotify) p2tr_edge_unref);
+  P2trVEdgeSet *encroached = p2tr_vedge_set_new ();
+  GList *iter;
 
-  P2trHashSetIter iter;
-  P2trEdge *e;
-  
-  p2tr_hash_set_iter_init (&iter, self->mesh->edges);
-  while (p2tr_hash_set_iter_next (&iter, (gpointer*)&e))
-    if (e->constrained
-        && p2tr_hash_set_contains (encroached_edges, e->mirror) == FALSE
-        && p2tr_cdt_is_encroached_by (self, e, C))
-      {
-        p2tr_hash_set_insert (encroached_edges, p2tr_edge_ref (e));
-      }
+  for (iter = v->outgoing_edges; iter != NULL; iter = iter->next)
+    {
+      P2trEdge *outEdge = (P2trEdge*) iter->data;
+      P2trTriangle *t = outEdge->tri;
+      P2trEdge *e;
+
+      if (t == NULL)
+          continue;
 
-  return encroached_edges;
+      e = p2tr_triangle_get_opposite_edge (t, v);
+
+      /* we want the fast check and for new points we don't
+       * use that check... So let's go on the full check
+       * since it's still faster */
+      if (e->constrained && p2tr_cdt_is_encroached (e))
+        p2tr_vedge_set_add2 (encroached, p2tr_vedge_new2 (e));
+    }
+
+  return encroached;
 }
 
 gboolean
@@ -291,7 +297,8 @@ p2tr_dt_refine (P2trDelaunayTerminator   *self,
           P2trCircle tCircum;
           P2trVector2 *c;
           P2trTriangle *triContaining_c;
-          P2trHashSet *E;
+          P2trVEdgeSet *E;
+          P2trPoint *cPoint;
 
           p2tr_cdt_validate_cdt (self->mesh);
           p2tr_triangle_get_circum_circle (t, &tCircum);
@@ -309,19 +316,24 @@ p2tr_dt_refine (P2trDelaunayTerminator   *self,
 
           /* Now, check if this point would encroach any edge
            * of the triangulation */
-          E = p2tr_cdt_get_segments_encroached_by (self->mesh, c);
+          p2tr_mesh_action_group_begin (self->mesh->mesh);
+
+          cPoint = p2tr_cdt_insert_point (self->mesh, c, triContaining_c);
+          E = p2tr_cdt_get_segments_encroached_by (self->mesh, cPoint);
 
-          if (p2tr_hash_set_size (E) == 0)
+          if (p2tr_vedge_set_size (E) == 0)
             {
-              P2trPoint *cPoint;
-              cPoint = p2tr_cdt_insert_point (self->mesh, c, triContaining_c);
+              p2tr_mesh_action_group_commit (self->mesh->mesh);
               NewVertex (self, cPoint, self->theta, self->delta);
-              
               p2tr_point_unref (cPoint);
             }
           else
             {
-              gdouble d = ShortestEdgeLength(t);
+              gdouble d;
+
+              p2tr_mesh_action_group_undo (self->mesh->mesh);
+
+              d = ShortestEdgeLength(t);
               
               p2tr_hash_set_iter_init (&hs_iter, E);
               while (p2tr_hash_set_iter_next (&hs_iter, (gpointer*)&s))
@@ -334,7 +346,9 @@ p2tr_dt_refine (P2trDelaunayTerminator   *self,
                   SplitEncroachedSubsegments(self, self->theta, self->delta);
                 }
             }
-          p2tr_hash_set_free (E);
+
+          p2tr_vedge_set_free (E);
+          p2tr_point_unref (cPoint);
           p2tr_triangle_unref (triContaining_c);
       }
 

diff --git a/poly2tri-c/refine/delaunay-terminator.h b/poly2tri-c/refine/delaunay-terminator.h
index 139bf253936fb07ce599334c9919bc4b7ee59d2b..217b9ba5aff8d8f9dc18a4e1bc2da9be5350d7a8 100644 (file)
--- a/poly2tri-c/refine/delaunay-terminator.h
+++ b/poly2tri-c/refine/delaunay-terminator.h
@@ -36,6 +36,7 @@
 #include <glib.h>
 #include "cdt.h"
 #include "refiner.h"
+#include "vedge.h"
 
 typedef struct
 {
@@ -53,8 +54,8 @@ gboolean  p2tr_cdt_is_encroached_by (P2trCDT     *self,
                                      P2trEdge    *e,
                                      P2trVector2 *p);
 
-P2trHashSet*  p2tr_cdt_get_segments_encroached_by (P2trCDT     *self,
-                                                   P2trVector2 *C);
+P2trVEdgeSet*  p2tr_cdt_get_segments_encroached_by (P2trCDT   *self,
+                                                    P2trPoint *v);
 
 gboolean      p2tr_cdt_is_encroached (P2trEdge *E);
 

diff --git a/poly2tri-c/refine/vedge.c b/poly2tri-c/refine/vedge.c
index b6b899ed893856117513b3ce582d90717f2cffe8..74a6a318898d8cbdf9757b833697d1b54ec677b3 100644 (file)
--- a/poly2tri-c/refine/vedge.c
+++ b/poly2tri-c/refine/vedge.c
@@ -198,6 +198,12 @@ p2tr_vedge_set_pop (P2trVEdgeSet  *self,
     return FALSE;
 }
 
+guint
+p2tr_vedge_set_size (P2trVEdgeSet *self)
+{
+  return p2tr_hash_set_size (self);
+}
+
 void
 p2tr_vedge_set_free (P2trVEdgeSet *self)
 {

diff --git a/poly2tri-c/refine/vedge.h b/poly2tri-c/refine/vedge.h
index 5685c3e97dfcbf23461d32141df36cc8b69f192c..30f0e8f3f98ed553e609ddacaaec1bb2cef3346a 100644 (file)
--- a/poly2tri-c/refine/vedge.h
+++ b/poly2tri-c/refine/vedge.h
@@ -123,6 +123,11 @@ void         p2tr_vedge_set_add2 (P2trVEdgeSet  *self,
 gboolean     p2tr_vedge_set_pop  (P2trVEdgeSet  *self,
                                   P2trVEdge    **value);
 
+/**
+ * Returns the amount of virtual edges currently in the set
+ */
+guint        p2tr_vedge_set_size (P2trVEdgeSet  *self);
+
 /**
  * Free the flip set. IT IS THE REPONSIBILITY OF THE CALLER TO MAKE
  * SURE NO VIRTUAL EDGES WERE LEFT IN THE SET!