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Diffstat (limited to 'include/ttl/halfedge/hetraits.h')
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diff --git a/include/ttl/halfedge/hetraits.h b/include/ttl/halfedge/hetraits.h new file mode 100644 index 0000000..04288a0 --- /dev/null +++ b/include/ttl/halfedge/hetraits.h @@ -0,0 +1,189 @@ +/* + * 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 |