add forgotten file (r48979).

AABB_tree/include/CGAL/Point_3_triangle_3_point_3_nearest_point_3.h

@@ -0,0 +1,247 @@
+// Copyright (c) 2009 INRIA Sophia-Antipolis (France).
+// All rights reserved.
+//
+// This file is part of CGAL (www.cgal.org); you may redistribute it under
+// the terms of the Q Public License version 1.0.
+// See the file LICENSE.QPL 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)     : Camille Wormser, Stephane Tayeb
+//
+//******************************************************************************
+// File Description :
+//
+//******************************************************************************
+
+#ifndef POINT_3_TRIANGLE_3_POINT_3_NEAREST_POINT_3_H_
+#define POINT_3_TRIANGLE_3_POINT_3_NEAREST_POINT_3_H_
+
+
+#include <CGAL/kernel_basic.h>
+#include <CGAL/enum.h>
+
+
+namespace CGAL {
+
+
+namespace CGALi {
+
+
+template <class K>
+inline
+bool
+is_inside_triangle_3_aux(const typename K::Vector_3& w,
+                         const typename K::Point_3& p1,
+                         const typename K::Point_3& p2,
+                         const typename K::Point_3& q,
+                         typename K::Point_3& result,
+                         bool& outside,
+                         const K& k)
+{
+  typedef typename K::Vector_3 Vector_3;
+  typedef typename K::FT FT;
+
+  typename K::Construct_vector_3 vector =
+    k.construct_vector_3_object();
+  typename K::Construct_projected_point_3 projection =
+    k.construct_projected_point_3_object();
+  typename K::Construct_line_3 line =
+    k.construct_line_3_object();
+  typename K::Compute_scalar_product_3 scalar_product =
+    k.compute_scalar_product_3_object();
+
+  const Vector_3 v = cross_product(vector(p1,p2), vector(p1,q), k);
+  if ( scalar_product(v,w) < FT(0))
+  {
+    if (   scalar_product(vector(p1,q), vector(p1,p2)) >= FT(0)
+        && scalar_product(vector(p2,q), vector(p2,p1)) >= FT(0) )
+    {
+      result = projection(line(p1, p2), q);
+      return true;
+    }
+    outside = true;
+  }
+
+  return false;
+}
+
+
+/**
+ * Returns the nearest point of p1,p2,p3 from origin
+ * @param origin the origin point
+ * @param p1 the first point
+ * @param p2 the second point
+ * @param p3 the third point
+ * @param k the kernel
+ * @return the nearest point from origin
+ */
+template <class K>
+inline
+typename K::Point_3
+nearest_point_3(const typename K::Point_3& origin,
+                const typename K::Point_3& p1,
+                const typename K::Point_3& p2,
+                const typename K::Point_3& p3,
+                const K& k)
+{
+  typedef typename K::FT FT;
+
+  typename K::Compute_squared_distance_3 sq_distance =
+    k.compute_squared_distance_3_object();
+
+  const FT dist_origin_p1 = sq_distance(origin,p1);
+  const FT dist_origin_p2 = sq_distance(origin,p2);
+  const FT dist_origin_p3 = sq_distance(origin,p3);
+
+  if (   dist_origin_p2 >= dist_origin_p1
+      && dist_origin_p3 >= dist_origin_p1 )
+  {
+    return p1;
+  }
+  if ( dist_origin_p3 >= dist_origin_p2 )
+  {
+    return p2;
+  }
+
+  return p3;
+}
+
+/**
+ * @brief returns true if p is inside triangle t. If p is not inside t,
+ * result is the nearest point of t from p. WARNING: it is assumed that
+ * t and p are on the same plane.
+ * @param p the reference point
+ * @param t the triangle
+ * @param result if p is not inside t, the nearest point of t from p
+ * @param k the kernel
+ * @return true if p is inside t
+ */
+template <class K>
+inline
+bool
+is_inside_triangle_3(const typename K::Point_3& p,
+                     const typename K::Triangle_3& t,
+                     typename K::Point_3& result,
+                     const K& k)
+{
+  typedef typename K::Point_3 Point_3;
+  typedef typename K::Vector_3 Vector_3;
+
+  typename K::Construct_vector_3 vector =
+    k.construct_vector_3_object();
+  typename K::Construct_vertex_3 vertex_on =
+    k.construct_vertex_3_object();
+
+  const Point_3& t0 = vertex_on(t,0);
+  const Point_3& t1 = vertex_on(t,1);
+  const Point_3& t2 = vertex_on(t,2);
+
+  Vector_3 w = cross_product(vector(t0,t1), vector(t1,t2),k);
+
+  bool outside = false;
+  if (   is_inside_triangle_3_aux(w, t0, t1, p, result, outside, k)
+      || is_inside_triangle_3_aux(w, t1, t2, p, result, outside, k)
+      || is_inside_triangle_3_aux(w, t2, t0, p, result, outside, k) )
+  {
+    return false;
+  }
+
+  if ( outside )
+  {
+    result = nearest_point_3(p,t0,t1,t2,k);
+    return false;
+  }
+  else
+  {
+    return true;
+  }
+}
+
+/**
+ * @brief Computes the closest_point from origin between bound and
+ * any point of triangle.
+ * @param origin the origin point
+ * @param triangle the triangle
+ * @param bound the farthest point
+ * @param k the kernel
+ * @return nearest point: bound or a point inside triangle
+ */
+template <class K>
+typename K::Point_3
+nearest_point_3(const typename K::Point_3& origin,
+                const typename K::Triangle_3& triangle,
+                const typename K::Point_3& bound,
+                const K& k)
+{
+  typedef typename K::Point_3 Point_3;
+  typedef typename K::Vector_3 Vector_3;
+  typedef typename K::FT FT;
+
+  typename K::Compute_squared_distance_3 sq_distance =
+    k.compute_squared_distance_3_object();
+  typename K::Compare_squared_distance_3 compare_sq_distance =
+    k.compare_squared_distance_3_object();
+  typename K::Construct_supporting_plane_3 supporting_plane =
+    k.construct_supporting_plane_3_object();
+  typename K::Construct_projected_point_3 projection =
+    k.construct_projected_point_3_object();
+
+
+  // Distance from origin to bound
+  const FT bound_sq_dist = sq_distance(origin, bound);
+
+  // Project origin on triangle supporting plane
+  const Point_3 proj = projection(supporting_plane(triangle), origin);
+
+  // If point is projected outside, return bound
+  if ( compare_sq_distance(origin, proj, bound_sq_dist) == CGAL::LARGER )
+  {
+    return bound;
+  }
+
+  Point_3 moved_point;
+  bool inside = is_inside_triangle_3(proj,triangle,moved_point,k);
+
+  // If proj is inside triangle, return it
+  if ( inside )
+  {
+    return proj;
+  }
+
+  // Else return the constructed point (nearest point of triangle from proj)
+  // if it is closest to origin than bound
+  if ( compare_sq_distance(origin, moved_point, bound_sq_dist)
+                                                        == CGAL::LARGER )
+  {
+    return bound;
+  }
+
+  return moved_point;
+}
+
+}  // end namespace CGALi
+
+
+template <class K>
+inline
+Point_3<K>
+nearest_point_3(const Point_3<K>& origin,
+                const Triangle_3<K>& triangle,
+                const Point_3<K>& bound)
+{
+  return CGALi::nearest_point_3(origin, triangle, bound, K());
+}
+
+}  // end namespace CGAL
+
+
+#endif // POINT_3_TRIANGLE_3_POINT_3_NEAREST_POINT_3_H_