90 lines
2.3 KiB
90 lines
2.3 KiB
// David Eberly, Geometric Tools, Redmond WA 98052
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// Copyright (c) 1998-2021
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// Distributed under the Boost Software License, Version 1.0.
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// https://www.boost.org/LICENSE_1_0.txt
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// https://www.geometrictools.com/License/Boost/LICENSE_1_0.txt
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// Version: 4.0.2019.08.13
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#pragma once
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#include <Mathematics/Vector.h>
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// The halfspace is represented as Dot(N,X) >= c where N is a unit-length
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// normal vector, c is the plane constant, and X is any point in space.
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// The user must ensure that the normal vector is unit length.
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namespace gte
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{
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template <int N, typename Real>
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class Halfspace
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{
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public:
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// Construction and destruction. The default constructor sets the
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// normal to (0,...,0,1) and the constant to zero (halfspace
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// x[N-1] >= 0).
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Halfspace()
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:
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constant((Real)0)
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{
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normal.MakeUnit(N - 1);
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}
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// Specify N and c directly.
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Halfspace(Vector<N, Real> const& inNormal, Real inConstant)
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:
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normal(inNormal),
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constant(inConstant)
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{
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}
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// Public member access.
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Vector<N, Real> normal;
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Real constant;
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public:
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// Comparisons to support sorted containers.
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bool operator==(Halfspace const& halfspace) const
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{
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return normal == halfspace.normal && constant == halfspace.constant;
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}
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bool operator!=(Halfspace const& halfspace) const
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{
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return !operator==(halfspace);
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}
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bool operator< (Halfspace const& halfspace) const
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{
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if (normal < halfspace.normal)
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{
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return true;
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}
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if (normal > halfspace.normal)
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{
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return false;
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}
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return constant < halfspace.constant;
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}
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bool operator<=(Halfspace const& halfspace) const
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{
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return !halfspace.operator<(*this);
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}
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bool operator> (Halfspace const& halfspace) const
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{
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return halfspace.operator<(*this);
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}
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bool operator>=(Halfspace const& halfspace) const
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{
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return !operator<(halfspace);
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}
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};
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// Template alias for convenience.
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template <typename Real>
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using Halfspace3 = Halfspace<3, Real>;
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}
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