public double Distance(Line3D line)
{
// test for parallel line which must be handled differently
var rx = Math.Abs(m_v.X / line.m_v.X);
var ry = Math.Abs(m_v.Y / line.m_v.Y);
var rz = Math.Abs(m_v.Z / line.m_v.Z);
if (Math.Abs(rx - ry) < kContainsEpsilon && Math.Abs(ry - rz) < kContainsEpsilon)
return DistanceOfParallelLine(line);
return DistanceOfSkewLine(line);
}
public double DistanceOfParallelLine(Line3D line)
{
var mpLp = line.m_p - m_p; // vector from m_p to line.m_p
var proj_v_mpLp = mpLp.ProjectSelfOnto(m_v);
var perp = mpLp - proj_v_mpLp;
return perp.Magnitude();
}
// http://math.stackexchange.com/questions/13734/how-to-find-shortest-distance-between-two-skew-lines-in-3d
public double DistanceOfSkewLine(Line3D line)
{
return m_v.Cross(line.m_v).ToUnitVector().Dot(m_p - line.m_p);
}