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* Regina - A Normal Surface Theory Calculator *
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* Computational Engine *
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* Copyright (c) 1999-2013, Ben Burton *
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* Copyright (c) 1999-2014, Ben Burton *
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* For further details contact Ben Burton (bab@debian.org). *
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* This program is free software; you can redistribute it and/or *
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* Represents quadrilateral coordinates for transversely oriented
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* normal surfaces.
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NS_ORIENTED_QUAD = 301
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NS_ORIENTED_QUAD = 301,
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* Represents angle structure coordinates.
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* This coordinate system is \e not for use with normal surfaces:
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* it cannot be used either to display them or enumerate them.
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* Instead it is for use with angle structures on triangulations.
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* Because the combinatorics and linear algebra of angle strutures
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* are tightly related to those of normal surfaces, we include
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* NS_ANGLE here so that angle structure routines can make use of
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* some of Regina's existing normal surface machinery.
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* For a triangulation with \a n tetrahedra, this system has
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* 3<i>n</i>+1 coordinates. The first 3<i>n</i> are analogous
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* to quadrilateral coordinates (specifically, for each
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* quadrilateral type \a Q, the corresponding angle structure coordinate
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* represents the pair of angles in the same tetrahedron that \a Q does
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* not meet). The final coordinate is a scaling coordinate, used to
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* projectivise the angle structure polytope so that it becomes a
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* polyhedral cone that is invariant under (positive) scaling.
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* If the final scaling coordinate is \a s, then a rational value of \a x
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* in any other coordinate position should be interpreted as the angle
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* <i>x</i>.π/<i>s</i>.
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* \pre This coordinate system must not be used with any of Regina's
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* routines unless they explicitly declare that NS_ANGLE is allowed.
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engine/surfaces/normalcoords.h
