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/**************************************************************************
* *
* Regina - A Normal Surface Theory Calculator *
* Computational Engine *
* *
* Copyright (c) 1999-2016, 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. *
* *
* As an exception, when this program is distributed through (i) the *
* App Store by Apple Inc.; (ii) the Mac App Store by Apple Inc.; or *
* (iii) Google Play by Google Inc., then that store may impose any *
* digital rights management, device limits and/or redistribution *
* restrictions that are required by its terms of service. *
* *
* 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. *
* *
**************************************************************************/
#include "maths/ray.h"
namespace regina {
void Ray::scaleDown() {
LargeInteger gcd; // Initialised to 0.
LargeInteger* e;
for (e = elements; e < end; ++e) {
if (e->isInfinite() || (*e) == zero)
continue;
gcd = gcd.gcd(*e);
if (gcd < 0)
gcd.negate();
if (gcd == one)
return;
}
if (gcd == zero)
return;
for (e = elements; e < end; ++e)
if ((! e->isInfinite()) && (*e) != zero) {
e->divByExact(gcd);
e->tryReduce();
}
}
} // namespace regina
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