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/**************************************************************************
* *
* Regina - A Normal Surface Theory Calculator *
* Computational Engine *
* *
* Copyright (c) 1999-2011, 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 "surfaces/normalspec.tcc"
#include "surfaces/nnormalsurface.h"
#include "surfaces/nnormalsurfacelist.h"
#include "surfaces/nsquad.h"
#include "surfaces/nsquadoct.h"
#include "triangulation/ntriangulation.h"
namespace regina {
// Although internalStandardToReduced() is a template routine, we implement
// it here in this C++ file to avoid dragging it into the headers.
//
// The following definitions should ensure that the template is fully
// instantiated where it needs to be.
NNormalSurfaceList* NNormalSurfaceList::standardToQuad() const {
return internalStandardToReduced<NormalSpec>();
}
NNormalSurfaceList* NNormalSurfaceList::standardANToQuadOct() const {
return internalStandardToReduced<AlmostNormalSpec>();
}
template <class Variant>
NNormalSurfaceList* NNormalSurfaceList::internalStandardToReduced() const {
// And off we go!
NTriangulation* owner = getTriangulation();
// Basic sanity checks:
if (flavour != Variant::standardFlavour() || ! embedded)
return 0;
if (owner->isIdeal() || ! owner->isValid())
return 0;
// Prepare a final surface list.
NNormalSurfaceList* ans = new NNormalSurfaceList(
Variant::reducedFlavour(), true);
// Get the empty triangulation out of the way now.
unsigned n = owner->getNumberOfTetrahedra();
if (n == 0) {
owner->insertChildLast(ans);
return ans;
}
// We need to get rid of vertex links entirely before we start.
typedef const NNormalSurfaceVector* VectorPtr;
VectorPtr* use = new VectorPtr[surfaces.size()];
unsigned long nUse = 0;
std::vector<NNormalSurface*>::const_iterator it;
for (it = surfaces.begin(); it != surfaces.end(); ++it)
if (! (*it)->isVertexLinking())
use[nUse++] = (*it)->rawVector();
// We want to take all surfaces with maximal zero sets in quad space.
// That is, we want surface S if and only if there is no other surface T
// where, for every quadrilateral coordinate where S is zero, T is
// zero also.
// For almost normal surfaces, simply replace "quadrilateral" with
// "quadrilateral or octagonal".
bool dominates, strict;
unsigned tet, quad, pos;
typename Variant::ReducedVector* v;
unsigned long i, j;
for (i = 0; i < nUse; ++i) {
if (use[i] == 0)
continue;
dominates = strict = false;
for (j = 0; j < nUse; ++j) {
if (j == i || use[j] == 0)
continue;
dominates = true;
strict = false;
for (tet = 0; tet < n && dominates; ++tet)
for (quad = 0; quad < Variant::reducedCoords; ++quad)
if ((*use[i])[Variant::stdPos(tet, 4 + quad)] ==
NLargeInteger::zero &&
(*use[j])[Variant::stdPos(tet, 4 + quad)] !=
NLargeInteger::zero) {
dominates = false;
break;
} else if ((*use[i])[Variant::stdPos(tet, 4 + quad)] !=
NLargeInteger::zero &&
(*use[j])[Variant::stdPos(tet, 4 + quad)] ==
NLargeInteger::zero) {
// If this *does* turn out to be a domination of
// zero sets, we know it's strict.
strict = true;
}
if (dominates)
break;
}
if (! dominates) {
// We want this surface.
v = new typename Variant::ReducedVector(Variant::redLen(n));
pos = 0;
for (tet = 0; tet < n; ++tet)
for (quad = 0; quad < Variant::reducedCoords; ++quad)
v->setElement(pos++,
(*use[i])[Variant::stdPos(tet, 4 + quad)]);
ans->surfaces.push_back(new NNormalSurface(owner, v));
} else if (strict) {
// We can drop this surface entirely from our list.
// We don't want it for our final solution set, and if
// use[i] is going to rule out some *other* surface then
// use[j] will rule out that same other surface also.
//
// The domination need to be strict because otherwise we
// might want use[i] to rule out use[j] (i.e., they both
// rule out each other).
use[i] = 0;
}
}
delete[] use;
// All done!
owner->insertChildLast(ans);
return ans;
}
} // namespace regina
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