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// Geometric Tools, LLC
// Copyright (c) 1998-2014
// Distributed under the Boost Software License, Version 1.0.
// http://www.boost.org/LICENSE_1_0.txt
// http://www.geometrictools.com/License/Boost/LICENSE_1_0.txt
//
// File Version: 5.0.1 (2010/10/01)
#include "Wm5MathematicsPCH.h"
#include "Wm5DistLine2Segment2.h"
namespace Wm5
{
//----------------------------------------------------------------------------
template <typename Real>
DistLine2Segment2<Real>::DistLine2Segment2 (const Line2<Real>& line,
const Segment2<Real>& segment)
:
mLine(&line),
mSegment(&segment)
{
}
//----------------------------------------------------------------------------
template <typename Real>
const Line2<Real>& DistLine2Segment2<Real>::GetLine () const
{
return *mLine;
}
//----------------------------------------------------------------------------
template <typename Real>
const Segment2<Real>& DistLine2Segment2<Real>::GetSegment () const
{
return *mSegment;
}
//----------------------------------------------------------------------------
template <typename Real>
Real DistLine2Segment2<Real>::Get ()
{
return Math<Real>::Sqrt(GetSquared());
}
//----------------------------------------------------------------------------
template <typename Real>
Real DistLine2Segment2<Real>::GetSquared ()
{
Vector2<Real> diff = mLine->Origin - mSegment->Center;
Real a01 = -mLine->Direction.Dot(mSegment->Direction);
Real b0 = diff.Dot(mLine->Direction);
Real c = diff.SquaredLength();
Real det = Math<Real>::FAbs((Real)1 - a01*a01);
Real b1, s0, s1, sqrDist, extDet;
if (det >= Math<Real>::ZERO_TOLERANCE)
{
// The line and segment are not parallel.
b1 = -diff.Dot(mSegment->Direction);
s1 = a01*b0 - b1;
extDet = mSegment->Extent*det;
if (s1 >= -extDet)
{
if (s1 <= extDet)
{
// Two interior points are closest, one on the line and one
// on the segment.
Real invDet = ((Real)1)/det;
s0 = (a01*b1 - b0)*invDet;
s1 *= invDet;
sqrDist = (Real)0;
}
else
{
// The endpoint e1 of the segment and an interior point of
// the line are closest.
s1 = mSegment->Extent;
s0 = -(a01*s1 + b0);
sqrDist = -s0*s0 +s1*(s1 + ((Real)2)*b1) + c;
}
}
else
{
// The endpoint e0 of the segment and an interior point of the
// line are closest.
s1 = -mSegment->Extent;
s0 = -(a01*s1 + b0);
sqrDist = -s0*s0 +s1*(s1 + ((Real)2)*b1) + c;
}
}
else
{
// The line and segment are parallel. Choose the closest pair so that
// one point is at segment origin.
s1 = (Real)0;
s0 = -b0;
sqrDist = b0*s0 + c;
}
mClosestPoint0 = mLine->Origin + s0*mLine->Direction;
mClosestPoint1 = mSegment->Center + s1*mSegment->Direction;
// Account for numerical round-off errors.
if (sqrDist < (Real)0)
{
sqrDist = (Real)0;
}
return sqrDist;
}
//----------------------------------------------------------------------------
template <typename Real>
Real DistLine2Segment2<Real>::Get (Real t, const Vector2<Real>& velocity0,
const Vector2<Real>& velocity1)
{
Vector2<Real> movedOrigin = mLine->Origin + t*velocity0;
Vector2<Real> movedCenter = mSegment->Center + t*velocity1;
Line2<Real> movedLine(movedOrigin, mLine->Direction);
Segment2<Real> movedSegment(movedCenter, mSegment->Direction,
mSegment->Extent);
return DistLine2Segment2<Real>(movedLine, movedSegment).Get();
}
//----------------------------------------------------------------------------
template <typename Real>
Real DistLine2Segment2<Real>::GetSquared (Real t,
const Vector2<Real>& velocity0, const Vector2<Real>& velocity1)
{
Vector2<Real> movedOrigin = mLine->Origin + t*velocity0;
Vector2<Real> movedCenter = mSegment->Center + t*velocity1;
Line2<Real> movedLine(movedOrigin, mLine->Direction);
Segment2<Real> movedSegment(movedCenter, mSegment->Direction,
mSegment->Extent);
return DistLine2Segment2<Real>(movedLine, movedSegment).GetSquared();
}
//----------------------------------------------------------------------------
//----------------------------------------------------------------------------
// Explicit instantiation.
//----------------------------------------------------------------------------
template WM5_MATHEMATICS_ITEM
class DistLine2Segment2<float>;
template WM5_MATHEMATICS_ITEM
class DistLine2Segment2<double>;
//----------------------------------------------------------------------------
}
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