From 807aec3803b13a6e874b83c4359738fb1477a625 Mon Sep 17 00:00:00 2001
From: cignoni <paolo.cignoni@isti.cnr.it>
Date: Thu, 4 Mar 2004 00:53:24 +0000
Subject: [PATCH] Initial commit

---
 vcg/complex/trimesh/update/topology.h | 178 ++++++++++++++++++++++++++
 1 file changed, 178 insertions(+)
 create mode 100644 vcg/complex/trimesh/update/topology.h

diff --git a/vcg/complex/trimesh/update/topology.h b/vcg/complex/trimesh/update/topology.h
new file mode 100644
index 00000000..38c3e048
--- /dev/null
+++ b/vcg/complex/trimesh/update/topology.h
@@ -0,0 +1,178 @@
+/****************************************************************************
+* VCGLib                                                            o o     *
+* Visual and Computer Graphics Library                            o     o   *
+*                                                                _   O  _   *
+* Copyright(C) 2004                                                \/)\/    *
+* Visual Computing Lab                                            /\/|      *
+* ISTI - Italian National Research Council                           |      *
+*                                                                    \      *
+* All rights reserved.                                                      *
+*                                                                           *
+* This program is free software; you can redistribute it and/or modify      *   
+* it under the terms of the GNU General Public License as published by      *
+* the Free Software Foundation; either version 2 of the License, or         *
+* (at your option) any later version.                                       *
+*                                                                           *
+* This program is distributed in the hope that it will be useful,           *
+* but WITHOUT ANY WARRANTY; without even the implied warranty of            *
+* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the             *
+* GNU General Public License (http://www.gnu.org/licenses/gpl.txt)          *
+* for more details.                                                         *
+*                                                                           *
+****************************************************************************/
+/****************************************************************************
+  History
+
+$Log: not supported by cvs2svn $
+
+****************************************************************************/
+#ifndef __VCG_TRI_UPDATE_TOPOLOGY
+#define __VCG_TRI_UPDATE_TOPOLOGY
+
+namespace vcg {
+namespace tri {
+
+template <class UpdateMeshType>
+class UpdateTopology
+{
+
+public:
+typedef UpdateMeshType MeshType; 
+typedef typename MeshType::VertexType     VertexType;
+typedef typename MeshType::VertexPointer  VertexPointer;
+typedef typename MeshType::VertexIterator VertexIterator;
+typedef typename MeshType::FaceType       FaceType;
+typedef typename MeshType::FacePointer    FacePointer;
+typedef typename MeshType::FaceIterator   FaceIterator;
+
+
+
+/// Auxiliairy data structure for computing face face adjacency information. 
+// It identifies and edge storing two vertex pointer and a face pointer where it belong.
+class PEdge
+{
+public:
+	
+	VertexPointer * v[2];		// the two Vertex pointer are ordered!
+	FacePointer   * f;		  // the face where this edge belong
+	int      z;				      // index in [0..2] of the edge of the face
+
+  PEdge() {}
+
+void Set( FacePointer * const pf, const int nz )
+{
+	assert(pf!=0);
+	assert(nz>=0);
+	assert(nz<3);
+	
+	v[0] = pf->V(nz);
+	v[1] = pf->V((nz+1)%3);
+	assert(v[0] != v[1]);
+
+	if( v[0] > v[1] ) swap(v[0],v[1]);
+	f    = pf;
+	z    = nz;
+}
+
+inline bool operator <  ( const PEdge & pe ) const
+{
+	if( v[0]<pe.v[0] ) return true;
+	else if( v[0]>pe.v[0] ) return false;
+	else return v[1] < pe.v[1];
+}
+
+inline bool operator <=  ( const PEdge & pe ) const
+{
+	if( v[0]<pe.v[0] ) return true;
+	else if( v[0]>pe.v[0] ) return false;
+	else return v[1] <= pe.v[1];
+}
+
+inline bool operator >  ( const PEdge & pe ) const
+{
+	if( v[0]>pe.v[0] ) return true;
+	else if( v[0]<pe.v[0] ) return false;
+	else return v[1] > pe.v[1];
+}
+
+inline bool operator >=  ( const PEdge & pe ) const
+{
+	if( v[0]>pe.v[0] ) return true;
+	else if( v[0]<pe.v[0] ) return false;
+	else return v[1] >= pe.v[1];
+}
+
+inline bool operator == ( const PEdge & pe ) const
+{
+	return v[0]==pe.v[0] && v[1]==pe.v[1];
+}
+
+inline bool operator != ( const PEdge & pe ) const
+{
+	return v[0]!=pe.v[0] || v[1]!=pe.v[1];
+}
+};
+
+
+
+void FaceFace(MeshType &m)
+{
+  if(!m.HasTopologyFF())		
+	{
+		vector<PEdge> e;
+		FaceIterator pf;
+		vector<PEdge>::iterator p;
+
+		if( fn == 0 ) return;
+
+		e.resize(fn*3);								// Alloco il vettore ausiliario
+		p = e.begin();
+		for(pf=face.begin();pf!=face.end();++pf)			// Lo riempio con i dati delle facce
+			if( ! (*pf).IsDeleted() )
+				for(int j=0;j<3;++j)
+				{
+					(*p).Set(&(*pf),j);
+					++p;
+				}
+		assert(p==e.end());
+		sort(e.begin(), e.end());							// Lo ordino per vertici
+	
+		int ne = 0;											// Numero di edge reali
+
+		vector<MPEDGE>::iterator pe,ps;
+		for(ps = e.begin(),pe=e.begin();pe<=e.end();++pe)	// Scansione vettore ausiliario
+		{
+			if( pe==e.end() || *pe != *ps )					// Trovo blocco di edge uguali
+			{
+				vector<MPEDGE>::iterator q,q_next;
+				for (q=ps;q<pe-1;++q)						// Scansione facce associate
+				{
+					assert((*q).z>=0);
+					assert((*q).z< 3);
+					q_next = q;
+					++q_next;
+					assert((*q_next).z>=0);
+					assert((*q_next).z< 3);
+					(*q).f->F(q->z) = (*q_next).f;				// Collegamento in lista delle facce
+					(*q).f->Z(q->z) = (*q_next).z;
+				}
+				assert((*q).z>=0);
+				assert((*q).z< 3);
+				(*q).f->F((*q).z) = ps->f;
+				(*q).f->Z((*q).z) = ps->z;
+				ps = pe;
+				++ne;										// Aggiorno il numero di edge
+			}
+		}
+	}
+}
+
+
+
+}; // end class
+
+}	// End namespace
+}	// End namespace
+
+
+#endif