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/*
* 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
* <http://www.gnu.org/licenses/>.
*
* 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 <ttl/halfedge/hetriang.h>
#include <ttl/halfedge/hedart.h>
namespace hed
{
/**
* \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;
/** @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& aV1, const DART& aV2 )
{
DART v10 = aV1;
v10.Alpha0();
DART v20 = aV2;
v20.Alpha0();
return ttl_util::ScalarProduct2D( v10.X() - aV1.X(), v10.Y() - aV1.Y(),
v20.X() - aV2.X(), v20.Y() - aV2.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& aV, const NODE_PTR& aP )
{
DART d0 = aV;
d0.Alpha0();
return ttl_util::ScalarProduct2D( d0.X() - aV.X(), d0.Y() - aV.Y(),
aP->GetX() - aV.X(), aP->GetY() - aV.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& aV1, const DART& aV2 )
{
DART v10 = aV1;
v10.Alpha0();
DART v20 = aV2;
v20.Alpha0();
return ttl_util::CrossProduct2D( v10.X() - aV1.X(), v10.Y() - aV1.Y(),
v20.X() - aV2.X(), v20.Y() - aV2.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& aV, const NODE_PTR& aP )
{
DART d0 = aV;
d0.Alpha0();
return ttl_util::CrossProduct2D( d0.X() - aV.X(), d0.Y() - aV.Y(),
aP->GetX() - aV.X(), aP->GetY() - aV.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& aN1, const DART& aN2, const NODE_PTR& aP )
{
REAL_TYPE pa[2];
REAL_TYPE pb[2];
REAL_TYPE pc[2];
pa[0] = aN1.X();
pa[1] = aN1.Y();
pb[0] = aN2.X();
pb[1] = aN2.Y();
pc[0] = aP->GetX();
pc[1] = aP->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& aN1, const DART& aN2, const DART& aP )
{
REAL_TYPE pa[2];
REAL_TYPE pb[2];
REAL_TYPE pc[2];
pa[0] = aN1.X();
pa[1] = aN1.Y();
pb[0] = aN2.X();
pb[1] = aN2.Y();
pc[0] = aP.X();
pc[1] = aP.Y();
return ttl_util::Orient2DFast( pa, pb, pc );
}
//@} // End of Geometric Predicates Group
};
}; // End of hed namespace
#endif
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