From e8908f774205efa074d139a024144c26d4ed376d Mon Sep 17 00:00:00 2001
From: cignoni <paolo.cignoni@isti.cnr.it>
Date: Fri, 26 Jun 2009 23:18:51 +0000
Subject: [PATCH] Added CountBitLargePolygons (better name suggestion?) for
 counting the number of polygons in the case that there are vertexes
 surrounded by faux edges too (like in the case of dodecahedron of platonic.h)

---
 vcg/complex/trimesh/clean.h | 50 ++++++++++++++++++++++++++++++++++++-
 1 file changed, 49 insertions(+), 1 deletion(-)

diff --git a/vcg/complex/trimesh/clean.h b/vcg/complex/trimesh/clean.h
index 259e8230..1e7afa11 100644
--- a/vcg/complex/trimesh/clean.h
+++ b/vcg/complex/trimesh/clean.h
@@ -307,6 +307,7 @@ private:
 			typedef typename MeshType::VertexType     VertexType;
 			typedef typename MeshType::VertexPointer  VertexPointer;
 			typedef typename MeshType::VertexIterator VertexIterator;
+			typedef typename MeshType::ConstVertexIterator ConstVertexIterator;
 			typedef	typename MeshType::ScalarType			ScalarType;
 			typedef typename MeshType::FaceType       FaceType;
 			typedef typename MeshType::FacePointer    FacePointer;
@@ -806,13 +807,60 @@ private:
         return m.fn - count/2;
       }
       
+		/**
+			* The number of polygonal faces is 
+			*  FN - EN_f (each faux edge hides exactly one triangular face or in other words a polygon of n edges has n-3 faux edges.)
+			* In the general case where a The number of polygonal faces is 
+			*	 FN - EN_f + VN_f 
+			*	where: 
+			*	 EN_f is the number of faux edges.
+			*	 VN_f is the number of faux vertices (e.g vertices completely surrounded by faux edges)
+      * as a intuitive proof think to a internal vertex that is collapsed onto a border of a polygon:
+			* it deletes 2 faces, 1 faux edges and 1 vertex so to keep the balance you have to add back the removed vertex.
+			*/
+			static int CountBitLargePolygons(MeshType &m) 
+			{
+			
+				UpdateFlags<MeshType>::VertexSetV(m);
+				// First loop Clear all referenced vertices
+				for (FaceIterator fi = m.face.begin(); fi != m.face.end(); ++fi) 
+						if (!fi->IsD())  
+								for(int i=0;i<3;++i) fi->V(i)->ClearV();
 
+				
+        // Second Loop, count (twice) faux edges and mark all vertices touched by non faux edges (e.g vertexes on the boundary of a polygon) 
+				if (!m.HasPerFaceFlags()) return m.fn;
+        typedef typename MeshType::FaceType F;
+        int countE = 0;
+				for (FaceIterator fi = m.face.begin(); fi != m.face.end(); ++fi) 
+						if (!fi->IsD())  {
+								for(int i=0;i<3;++i)
+								{
+									if (fi->IsF(i)) 
+											countE++;
+									else
+									{
+											fi->V0(i)->SetV();
+											fi->V1(i)->SetV();
+									}
+								}
+				}
+				// Third Loop, count the number of referenced vertexes that are completely surrounded by faux edges.
+
+        int countV = 0; 
+				for (VertexIterator vi = m.vert.begin(); vi != m.vert.end(); ++vi) 
+						if (!vi->IsD() && !vi->IsV()) countV++;
+				
+        return m.fn - countE/2 + countV ;
+      }
+      
+			
       /**
 			 * Checks that the mesh has consistent per-face faux edges
 			 * (the ones that merges triangles into larger polygons).
 			 * A border edge should never be faux, and faux edges should always be
 			 * reciprocated by another faux edges.
-			 * Requires FF adjiacency.
+			 * It requires FF adjacency.
 			 */
       static bool HasConsistentPerFaceFauxFlag(const MeshType &m)
       {