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/**************************************************************************
* *
* Regina - A Normal Surface Theory Calculator *
* Computational Engine *
* *
* Copyright (c) 1999-2008, 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/ncompconstraint.h"
#include "surfaces/nsanstandard.h"
#include "utilities/nrational.h"
#include "maths/nmatrixint.h"
#include "maths/nvectorunit.h"
#include "triangulation/ntriangulation.h"
namespace regina {
NLargeInteger NNormalSurfaceVectorANStandard::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, quads and octagons meeting that edge.
// Triangles:
NLargeInteger ans((*this)[10 * tetIndex + start]);
ans += (*this)[10 * tetIndex + end];
// Quads:
ans += (*this)[10 * tetIndex + 4 + vertexSplitMeeting[start][end][0]];
ans += (*this)[10 * tetIndex + 4 + vertexSplitMeeting[start][end][1]];
// Octagons:
ans += (*this)[10 * tetIndex + 7];
ans += (*this)[10 * tetIndex + 8];
ans += (*this)[10 * tetIndex + 9];
ans += (*this)[10 * tetIndex + 7 + vertexSplit[start][end]];
return ans;
}
NLargeInteger NNormalSurfaceVectorANStandard::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 discs meeting that face in that required arc.
// Triangles:
NLargeInteger ans((*this)[10 * tetIndex + vertex]);
// Quads:
ans += (*this)[10 * tetIndex + 4 + vertexSplit[vertex][backOfFace]];
// Octagons:
ans += (*this)[10 * tetIndex + 7 +
vertexSplitMeeting[vertex][backOfFace][0]];
ans += (*this)[10 * tetIndex + 7 +
vertexSplitMeeting[vertex][backOfFace][1]];
return ans;
}
NMatrixInt* NNormalSurfaceVectorANStandard::makeMatchingEquations(
NTriangulation* triangulation) {
unsigned long nCoords = 10 * triangulation->getNumberOfTetrahedra();
// Three equations per non-boundary face.
// F_boundary + 2 F_internal = 4 T
long nEquations = 3 * (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;
NPerm perm0, perm1;
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++) {
// Triangles:
ans->entry(row, 10*tet0 + perm0[i]) += 1;
ans->entry(row, 10*tet1 + perm1[i]) -= 1;
// Quads:
ans->entry(row, 10*tet0 + 4 +
vertexSplit[perm0[i]][perm0[3]]) += 1;
ans->entry(row, 10*tet1 + 4 +
vertexSplit[perm1[i]][perm1[3]]) -= 1;
// Octagons:
ans->entry(row, 10*tet0 + 7 +
vertexSplitMeeting[perm0[i]][perm0[3]][0]) += 1;
ans->entry(row, 10*tet1 + 7 +
vertexSplitMeeting[perm1[i]][perm1[3]][0]) -= 1;
ans->entry(row, 10*tet0 + 7 +
vertexSplitMeeting[perm0[i]][perm0[3]][1]) += 1;
ans->entry(row, 10*tet1 + 7 +
vertexSplitMeeting[perm1[i]][perm1[3]][1]) -= 1;
row++;
}
}
}
return ans;
}
NCompConstraintSet* NNormalSurfaceVectorANStandard::makeEmbeddedConstraints(
NTriangulation* triangulation) {
// At most one quad/oct per tetrahedron.
// Also at most one oct type overall.
NCompConstraintSet* ans = new NCompConstraintSet();
NCompConstraint* globalOctConstraint = new NCompConstraint(1);
std::set<unsigned>& globalOctCoords(globalOctConstraint->getCoordinates());
NCompConstraint* constraint;
unsigned i;
unsigned long base = 0;
for (unsigned long tet = 0; tet < triangulation->getNumberOfTetrahedra();
tet++) {
constraint = new NCompConstraint(1);
for (i = 4; i < 10; i++)
constraint->getCoordinates().insert(
constraint->getCoordinates().end(), base + i);
for (i = 7; i < 10; i++)
globalOctCoords.insert(globalOctCoords.end(), base + i);
base += 10;
ans->push_back(constraint);
}
ans->push_back(globalOctConstraint);
return ans;
}
} // namespace regina
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