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/**************************************************************************
* *
* Regina - A Normal Surface Theory Calculator *
* Computational Engine *
* *
* Copyright (c) 1999-2009, Ben Burton *
* For further details contact Ben Burton (bab@debian.org). *
* *
* This program is free software; you can redistribute it and/or *
* modify it under the terms of the GNU General Public License as *
* published by the Free Software Foundation; either version 2 of the *
* License, or (at your option) any later version. *
* *
* This program 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 *
* General Public License for more details. *
* *
* You should have received a copy of the GNU General Public *
* License along with this program; if not, write to the Free *
* Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, *
* MA 02110-1301, USA. *
* *
**************************************************************************/
/* end stub */
#include "enumerate/nenumconstraint.h"
#include "surfaces/nsoriented.h"
#include "maths/nmatrixint.h"
#include "maths/nrational.h"
#include "triangulation/ntriangulation.h"
namespace regina {
NLargeInteger NNormalSurfaceVectorOriented::getEdgeWeight(
unsigned long edgeIndex, NTriangulation* triang) const {
// Find a tetrahedron next to the edge in question.
const NEdgeEmbedding& emb = triang->getEdges()[edgeIndex]->
getEmbeddings().front();
long tetIndex = triang->tetrahedronIndex(emb.getTetrahedron());
int start = emb.getVertices()[0];
int end = emb.getVertices()[1];
// Add up the triangles and quads meeting that edge.
// Triangles:
NLargeInteger ans(getTriangleCoord(tetIndex,start,triang));
ans += getTriangleCoord(tetIndex,end,triang);
// Quads:
ans += getQuadCoord(tetIndex,vertexSplitMeeting[start][end][0],triang);
ans += getQuadCoord(tetIndex,vertexSplitMeeting[start][end][1],triang);
return ans;
}
NLargeInteger NNormalSurfaceVectorOriented::getFaceArcs(
unsigned long faceIndex, int faceVertex, NTriangulation* triang) const {
// Find a tetrahedron next to the face in question.
const NFaceEmbedding& emb = triang->getFaces()[faceIndex]->
getEmbedding(0);
long tetIndex = triang->tetrahedronIndex(emb.getTetrahedron());
int vertex = emb.getVertices()[faceVertex];
int backOfFace = emb.getVertices()[3];
// Add up the triangles and quads meeting that face in the required arc.
// Triangles:
NLargeInteger ans(getTriangleCoord(tetIndex,vertex,triang));
// Quads:
ans += getQuadCoord(tetIndex,vertexSplit[vertex][backOfFace],triang);
return ans;
}
NNormalSurfaceVector* NNormalSurfaceVectorOriented::makeZeroVector(
const NTriangulation* triangulation) {
return new NNormalSurfaceVectorOriented(
14 * triangulation->getNumberOfTetrahedra());
}
NMatrixInt* NNormalSurfaceVectorOriented::makeMatchingEquations(
NTriangulation* triangulation) {
unsigned long nCoords = 14 * triangulation->getNumberOfTetrahedra();
// Six equations per non-boundary face.
// F_boundary + 2 F_internal = 4 T
long nEquations = 6 * (4 * long(triangulation->getNumberOfTetrahedra()) -
long(triangulation->getNumberOfFaces()));
NMatrixInt* ans = new NMatrixInt(nEquations, nCoords);
// Run through each internal face and add the corresponding three
// equations.
unsigned row = 0;
int i;
unsigned long tet0, tet1;
NPerm4 perm0, perm1;
bool natural;
for (NTriangulation::FaceIterator fit = triangulation->getFaces().begin();
fit != triangulation->getFaces().end(); fit++) {
if (! (*fit)->isBoundary()) {
tet0 = triangulation->tetrahedronIndex(
(*fit)->getEmbedding(0).getTetrahedron());
tet1 = triangulation->tetrahedronIndex(
(*fit)->getEmbedding(1).getTetrahedron());
perm0 = (*fit)->getEmbedding(0).getVertices();
perm1 = (*fit)->getEmbedding(1).getVertices();
for (i=0; i<3; i++) {
// row: oriented towards the vertex of the face
// row+1: oriented towards the opposite face
// Triangles:
ans->entry(row, 14*tet0 + 2*perm0[i]) += 1;
ans->entry(row+1, 14*tet0 + 2*perm0[i] + 1) += 1;
ans->entry(row, 14*tet1 + 2*perm1[i]) -= 1;
ans->entry(row+1, 14*tet1 + 2*perm1[i] + 1) -= 1;
// Quads:
natural = (perm0[i] == 0 || perm0[3] == 0);
ans->entry(row, 14*tet0 + 8 +
2*vertexSplit[perm0[i]][perm0[3]] +
(natural ? 0 : 1)) += 1;
ans->entry(row+1, 14*tet0 + 8 +
2*vertexSplit[perm0[i]][perm0[3]] +
(natural ? 1 : 0)) += 1;
natural = (perm1[i] == 0 || perm1[3] == 0);
ans->entry(row, 14*tet1 + 8 +
2*vertexSplit[perm1[i]][perm1[3]] +
(natural ? 0 : 1)) -= 1;
ans->entry(row+1, 14*tet1 + 8 +
2*vertexSplit[perm1[i]][perm1[3]] +
(natural ? 1 : 0)) -= 1;
row+=2;
}
}
}
return ans;
}
NEnumConstraintList* NNormalSurfaceVectorOriented::makeEmbeddedConstraints(
NTriangulation* triangulation) {
// TODO: Must be a neater way of doing this, but might mean re-working
// bitmasks.
NEnumConstraintList* ans = new NEnumConstraintList(
8 * triangulation->getNumberOfTetrahedra());
unsigned base = 0;
unsigned c = 0;
while (c < ans->size()) {
for (unsigned d = 0; d < 2; d++) {
for (unsigned e = 0; e < 2; e++) {
for (unsigned f = 0; f < 2; f++) {
(*ans)[c].insert((*ans)[c].end(), base + 8 + d);
(*ans)[c].insert((*ans)[c].end(), base + 10 + e);
(*ans)[c].insert((*ans)[c].end(), base + 12 + f);
++c;
}
}
}
base += 14;
}
return ans;
}
} // namespace regina
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