- Merge H2 and H3 into Homogeneous_kernel.

2006-03-06 23:51:27 +00:00
parent bcf05d4b2d
commit 0ec1b0efcc
41 changed files with 480 additions and 478 deletions
@@ -0,0 +1,75 @@
+// Copyright (c) 1999  Utrecht University (The Netherlands),
+// ETH Zurich (Switzerland), Freie Universitaet Berlin (Germany),
+// INRIA Sophia-Antipolis (France), Martin-Luther-University Halle-Wittenberg
+// (Germany), Max-Planck-Institute Saarbruecken (Germany), RISC Linz (Austria),
+// and Tel-Aviv University (Israel).  All rights reserved.
+//
+// This file is part of CGAL (www.cgal.org); you can redistribute it and/or
+// modify it under the terms of the GNU Lesser General Public License as
+// published by the Free Software Foundation; version 2.1 of the License.
+// See the file LICENSE.LGPL distributed with CGAL.
+//
+// Licensees holding a valid commercial license may use this file in
+// accordance with the commercial license agreement provided with the software.
+//
+// This file is provided AS IS with NO WARRANTY OF ANY KIND, INCLUDING THE
+// WARRANTY OF DESIGN, MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
+//
+// $URL$
+// $Id$
+// 
+//
+// Author(s)     : Sven Schoenherr
+//                 Stefan Schirra
+ 
+
+#ifndef CGAL_BASIC_CONSTRUCTIONSH2_H
+#define CGAL_BASIC_CONSTRUCTIONSH2_H
+
+#include <CGAL/Homogeneous/PointH2.h>
+#include <CGAL/Homogeneous/LineH2.h>
+
+CGAL_BEGIN_NAMESPACE
+
+template <class R>
+CGAL_KERNEL_MEDIUM_INLINE
+typename R::Point_2
+gp_linear_intersection(const LineH2<R>& l1, const LineH2<R>& l2)
+{
+  return typename R::Point_2( l1.b()*l2.c() - l2.b()*l1.c(),
+                              l2.a()*l1.c() - l1.a()*l2.c(),
+                              l1.a()*l2.b() - l2.a()*l1.b() );
+}
+
+template <class R>
+CGAL_KERNEL_MEDIUM_INLINE
+typename R::FT
+squared_distance( const PointH2<R>& p, const PointH2<R>& q )
+{
+  typedef typename R::RT RT;
+  typedef typename R::FT FT;
+
+  const RT & phx = p.hx();
+  const RT & phy = p.hy();
+  const RT & phw = p.hw();
+  const RT & qhx = q.hx();
+  const RT & qhy = q.hy();
+  const RT & qhw = q.hw();
+
+  RT sq_dist_numerator =
+          phx * phx * qhw * qhw
+    - RT(2) * phx * qhx * phw * qhw
+    +     qhx * qhx * phw * phw
+
+    +     phy * phy * qhw * qhw
+    - RT(2) * phy * qhy * phw * qhw
+    +     qhy * qhy * phw * phw ;
+
+  RT sq_dist_denominator = qhw * qhw * phw * phw ;
+
+  return FT( sq_dist_numerator ) / FT( sq_dist_denominator );
+}
+
+CGAL_END_NAMESPACE
+
+#endif // CGAL_BASIC_CONSTRUCTIONSH2_H