new file for helper functions, which normalize the coordinates of

Point_3 and Plane_3 instances.

Packages/Nef_3/include/CGAL/Nef_3/Normalizing.h

@@ -0,0 +1,130 @@
+// ============================================================================
+//
+// Copyright (c) 1997-2002 The CGAL Consortium
+//
+// This software and related docuhmentation is part of an INTERNAL release
+// of the Computational Geometry Algorithms Library (CGAL). It is not
+// intended for general use.
+//
+// ----------------------------------------------------------------------------
+//
+// release       : $CGAL_Revision: $
+// release_date  : $CGAL_Date: $
+//
+// file          : include/CGAL/Nef_3/SNC_constructor.h
+// package       : Nef_3
+// chapter       : 3D-Nef Polyhedra
+//
+// revision      : $Revision$
+// revision_date : $Date$
+//
+// author(s)     : Peter Hachenberger  <hachenberger@mpi-sb.mpg.de>
+// maintainer    : Peter Hachenberger  <hachenberger@mpi-sb.mpg.de>
+// coordinator   : MPI Saarbruecken
+//
+// helper functions for normalizing Plane_3, etc.
+// ============================================================================
+#ifndef CGAL_NORMALIZING_H
+#define CGAL_NORMALIZING_H
+
+#include <CGAL/basic.h>
+#undef _DEBUG
+#define _DEBUG 307
+#include <CGAL/Nef_3/debug.h>
+
+template <typename R>
+CGAL::Point_3<R> simplified(CGAL::Point_3<R>& p)
+{
+  int deg = (p.hx().degree() > p.hy().degree() ? p.hx().degree() : p.hy().degree());
+  deg = (p.hz().degree() > deg ? p.hz().degree() : deg);
+  return CGAL::Point_3<R>(p.hx()(deg),p.hy()(deg),p.hz()(deg),p.hw()[0]);
+}
+
+template <typename R>
+CGAL::Point_3<R> normalized(CGAL::Point_3<R>& p)
+{ 
+  typedef typename R::RT     RT;
+
+  RT g = p.hw();
+  g = (p.hx() == 0 ? g : gcd(g,p.hx()));
+  g = (p.hy() == 0 ? g : gcd(g,p.hy()));
+  g = (p.hz() == 0 ? g : gcd(g,p.hz()));
+  
+  RT x = p.hx()/g;
+  RT y = p.hy()/g;
+  RT z = p.hz()/g;
+  RT w = p.hw()/g;
+  
+  return CGAL::Point_3<R>(x,y,z,w);
+}
+
+template <typename R>
+CGAL::Plane_3<R> normalized(CGAL::Plane_3<R>& h)
+{ 
+
+  CGAL_nef3_assertion(!(h.a()==0 && h.b()==0 && h.c()==0 && h.d()==0));
+  
+  typedef typename R::RT     RT;
+
+  RT x = (h.a()==0) ? ((h.b()==0) ? ((h.c()==0) ? ((h.d()==0) ? 1: h.d()): h.c()): h.b()): h.a();
+  
+  TRACE("gcd... i"<<' ');
+  
+  if(h.b() != 0)
+    x = gcd(x,h.b());
+  TRACE(x<<' ');
+  if(h.c() != 0)
+    x = gcd(x,h.c());
+  TRACE(x<<' ');
+  if(h.d() !=0)
+    x = gcd(x,h.d());
+  TRACEN(x);
+ 
+  x = x.abs();
+
+  RT pa = h.a()/x;
+  RT pb = h.b()/x;
+  RT pc = h.c()/x;
+  RT pd = h.d()/x;
+  
+  TRACEN("  after normalizing "  << CGAL::Plane_3<R>(pa,pb,pc,pd));
+  return CGAL::Plane_3<R>(pa,pb,pc,pd);
+}
+
+template <typename R>
+CGAL::Plane_3<R> normalized_old(CGAL::Plane_3<R>& h)
+{ 
+  //  TRACEN("  before normalizing "<<h);
+  CGAL_nef3_assertion(h.a().degree()==0 && h.b().degree()==0 && h.c().degree()==0 && h.d().degree()<2);
+  
+  typedef typename R::RT::NT NT;
+  typedef typename R::RT     RT;
+  NT a(h.a()[0]),b(h.b()[0]),c(h.c()[0]),d(h.d()[0]);
+  if(h.d().degree()==1)
+    if(d==0)
+      d=h.d()[1];
+    else
+      d=CGAL_NTS gcd(d,h.d()[1]);
+
+  NT x = (a==0) ? ((b==0) ? ((c==0) ? ((d==0) ? 1: d): c): b): a;
+  //  TRACE("gcd... i"<<x<<' ');
+  x = ( a != 0 ? a : x);
+  //  TRACE(x<<' ');
+  x = ( b != 0 ? CGAL_NTS gcd(x,b) : x );
+  //  TRACE(x<<' ');
+  x = ( c != 0 ? CGAL_NTS gcd(x,c) : x );
+  //  TRACE(x<<' ');
+  x = ( d != 0 ? CGAL_NTS gcd(x,d) : x );
+  //  TRACEN(x);
+  //  CGAL_nef3_assertion( h == CGAL::Plane_3<R>(a/x,b/x,c/x,d/x));
+
+ 
+  RT pa = a/x;
+  RT pb = b/x;
+  RT pc = c/x;
+  RT pd = h.d()/x;
+  
+  return CGAL::Plane_3<R>(pa,pb,pc,pd);
+}
+
+#endif // CGAL_NORMALIZING_H