/*
* Copyright (C) 1998, 2000-2007, 2010, 2011, 2012, 2013 SINTEF ICT,
* Applied Mathematics, Norway.
*
* Contact information: E-mail: tor.dokken@sintef.no
* SINTEF ICT, Department of Applied Mathematics,
* P.O. Box 124 Blindern,
* 0314 Oslo, Norway.
*
* This file is part of TTL.
*
* TTL is free software: you can redistribute it and/or modify
* it under the terms of the GNU Affero General Public License as
* published by the Free Software Foundation, either version 3 of the
* License, or (at your option) any later version.
*
* TTL 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 Affero General Public License for more details.
*
* You should have received a copy of the GNU Affero General Public
* License along with TTL. If not, see
* .
*
* In accordance with Section 7(b) of the GNU Affero General Public
* License, a covered work must retain the producer line in every data
* file that is created or manipulated using TTL.
*
* Other Usage
* You can be released from the requirements of the license by purchasing
* a commercial license. Buying such a license is mandatory as soon as you
* develop commercial activities involving the TTL library without
* disclosing the source code of your own applications.
*
* This file may be used in accordance with the terms contained in a
* written agreement between you and SINTEF ICT.
*/
#ifndef _HALF_EDGE_TRAITS_
#define _HALF_EDGE_TRAITS_
#include
#include
namespace hed {
//------------------------------------------------------------------------------------------------
// Traits class for the half-edge data structure
//------------------------------------------------------------------------------------------------
/** \struct TTLtraits
* \brief \b Traits class (static struct) for the half-edge data structure.
*
* The member functions are those required by different function templates
* in the TTL. Documentation is given here to explain what actions
* should be carried out on the actual data structure as required by the functions
* in the \ref ttl namespace.
*
* The source code of \c %HeTraits.h shows how the traits class is implemented for the
* half-edge data structure.
*
* \see \ref api
*
*/
struct TTLtraits {
/** The floating point type used in calculations
* involving scalar products and cross products.
*/
typedef double real_type;
//----------------------------------------------------------------------------------------------
// ------------------------------- Geometric Predicates Group ---------------------------------
//----------------------------------------------------------------------------------------------
/** @name Geometric Predicates */
//@{
//----------------------------------------------------------------------------------------------
/** Scalar product between two 2D vectors represented as darts.\n
*
* ttl_util::scalarProduct2d can be used.
*/
static real_type scalarProduct2d(const Dart& v1, const Dart& v2) {
Dart v10 = v1; v10.alpha0();
Dart v20 = v2; v20.alpha0();
return ttl_util::scalarProduct2d(v10.x()-v1.x(), v10.y()-v1.y(),
v20.x()-v2.x(), v20.y()-v2.y());
}
//----------------------------------------------------------------------------------------------
/** Scalar product between two 2D vectors.
* The first vector is represented by a dart \e v, and the second
* vector has direction from the source node of \e v to the point \e p.\n
*
* ttl_util::scalarProduct2d can be used.
*/
static real_type scalarProduct2d(const Dart& v, const NodePtr& p) {
Dart d0 = v; d0.alpha0();
return ttl_util::scalarProduct2d(d0.x() - v.x(), d0.y() - v.y(),
p->GetX() - v.x(), p->GetY() - v.y());
}
//----------------------------------------------------------------------------------------------
/** Cross product between two vectors in the plane represented as darts.
* The z-component of the cross product is returned.\n
*
* ttl_util::crossProduct2d can be used.
*/
static real_type crossProduct2d(const Dart& v1, const Dart& v2) {
Dart v10 = v1; v10.alpha0();
Dart v20 = v2; v20.alpha0();
return ttl_util::crossProduct2d(v10.x()-v1.x(), v10.y()-v1.y(),
v20.x()-v2.x(), v20.y()-v2.y());
}
//----------------------------------------------------------------------------------------------
/** Cross product between two vectors in the plane.
* The first vector is represented by a dart \e v, and the second
* vector has direction from the source node of \e v to the point \e p.
* The z-component of the cross product is returned.\n
*
* ttl_util::crossProduct2d can be used.
*/
static real_type crossProduct2d(const Dart& v, const NodePtr& p) {
Dart d0 = v; d0.alpha0();
return ttl_util::crossProduct2d(d0.x() - v.x(), d0.y() - v.y(),
p->GetX() - v.x(), p->GetY() - v.y());
}
//----------------------------------------------------------------------------------------------
/** Let \e n1 and \e n2 be the nodes associated with two darts, and let \e p
* be a point in the plane. Return a positive value if \e n1, \e n2,
* and \e p occur in counterclockwise order; a negative value if they occur
* in clockwise order; and zero if they are collinear.
*/
static real_type orient2d(const Dart& n1, const Dart& n2, const NodePtr& p) {
real_type pa[2]; real_type pb[2]; real_type pc[2];
pa[0] = n1.x(); pa[1] = n1.y();
pb[0] = n2.x(); pb[1] = n2.y();
pc[0] = p->GetX(); pc[1] = p->GetY();
return ttl_util::orient2dfast(pa, pb, pc);
}
//----------------------------------------------------------------------------------------------
/** This is the same predicate as represented with the function above,
* but with a slighty different interface:
* The last parameter is given as a dart where the source node of the dart
* represents a point in the plane.
* This function is required for constrained triangulation.
*/
static real_type orient2d(const Dart& n1, const Dart& n2, const Dart& p) {
real_type pa[2]; real_type pb[2]; real_type pc[2];
pa[0] = n1.x(); pa[1] = n1.y();
pb[0] = n2.x(); pb[1] = n2.y();
pc[0] = p.x(); pc[1] = p.y();
return ttl_util::orient2dfast(pa, pb, pc);
}
//@} // End of Geometric Predicates Group
};
}; // End of hed namespace
#endif