protected double GetSegmentDistance()
{
double l02 = L0.L.OrigDist2();
if (IsParallel)
{
Pnt s = L1.Ps - L0.Ps;
double f0 = s * L0.L / l02;
if (f0 >= 0 && f0 <= 1)
{
return(Math.Abs(L0.L.VectorProduct(s) / Math.Sqrt(l02)));
}
Pnt e = L1.Pe - L0.Ps;
double f1 = e * L0.L / l02;
if ((f1 >= 0 && f1 <= 1) || (f0 < 0 != f1 < 0))
{
return(Math.Abs(L0.L.VectorProduct(s) / Math.Sqrt(l02)));
}
double d2 = Math.Min(s.OrigDist2(), e.OrigDist2());
d2 = Math.Min(d2, (L1.Ps - L0.Pe).OrigDist2());
d2 = Math.Min(d2, (L1.Pe - L0.Pe).OrigDist2());
return(Math.Sqrt(d2));
}
{
Pnt s = L1.Ps - L0.Ps;
double f1S = L0.L.VectorProduct(s);
Pnt e = L1.Pe - L0.Ps;
double f1E = L0.L.VectorProduct(e);
double f1 = -f1S / (f1E - f1S);
Pnt cut = L1.Ps + f1 * L1.L;
double f0 = L0.L * (cut - L0.Ps) / l02;
if (f0 >= 0 && f0 <= 1 && f1 >= 0 && f1 <= 1)
{
return(0);
}
double d2 = Math.Min(GetPointDistance(L0.L, l02, s, f1S),
GetPointDistance(L0.L, l02, e, f1E));
d2 = Math.Min(d2, GetPointDistance(L1.L, L1.L2, L0.Ps - L1.Ps, null));
d2 = Math.Min(d2, GetPointDistance(L1.L, L1.L2, L0.Pe - L1.Ps, null));
return(Math.Sqrt(d2));
}
}
private static double GetPointDistance([NotNull] Pnt line,
double line2,
[NotNull] Pnt p,
double?vectorProd)
{
double d2;
double f = line * p / line2;
if (f >= 0 && f <= 1)
{
double v = vectorProd ?? line.VectorProduct(p);
d2 = v * v / line2;
}
else
{
d2 = Math.Min(p.OrigDist2(), (p - line).OrigDist2());
}
return(d2);
}
private void CutCircle(Pnt segStart, Pnt segmentLine, double offset, ref double tMin,
ref double tMax)
{
Pnt near = _center - segStart;
double centerOffset = SegmentUtils.GetOffset(near, segmentLine);
if (Math.Abs(centerOffset) < offset)
{
double centerAlong = SegmentUtils.GetAlongFraction(near, segmentLine);
double segmentLength = Math.Sqrt(segmentLine.OrigDist2());
tMin = Math.Min(tMin, centerAlong - _radius / segmentLength);
tMax = Math.Max(tMax, centerAlong + _radius / segmentLength);
}
else if (_radius + offset > Math.Abs(centerOffset))
{
Pnt offsetCenter;
if (offset <= 0)
{
offsetCenter = _center;
}
else
{
double centerAlong = SegmentUtils.GetAlongFraction(near, segmentLine);
Pnt along = segStart + centerAlong * segmentLine;
double f = (Math.Abs(centerOffset) - offset) / Math.Abs(centerOffset);
offsetCenter = along + f * (_center - along);
}
double tCircleMin, tCircleMax;
if (SegmentUtils.CutLineCircle(segStart, segmentLine, offsetCenter,
_radius * _radius,
out tCircleMin, out tCircleMax))
{
tMin = Math.Min(tMin, tCircleMin);
tMax = Math.Max(tMax, tCircleMax);
}
}
}
internal static double GetAlongFraction([NotNull] Pnt nearPoint,
[NotNull] Pnt segmentLine)
{
return(nearPoint * segmentLine / segmentLine.OrigDist2());
}
internal static double GetOffset([NotNull] Pnt nearPoint, [NotNull] Pnt segmentLine)
{
double segmentLength = Math.Sqrt(segmentLine.OrigDist2());
return(nearPoint.VectorProduct(segmentLine) / segmentLength);
}
private void CutArc(Pnt segStart, Pnt segmentLine, double offset, ref double tMin,
ref double tMax)
{
Pnt near = _center - segStart;
double centerOffset = SegmentUtils.GetOffset(near, segmentLine);
if (Math.Abs(centerOffset) < offset)
{
var canReturn = false;
double lineAngle = Math.Atan2(segmentLine.Y, segmentLine.X);
double centerAlong = SegmentUtils.GetAlongFraction(near, segmentLine);
double segmentLength = Math.Sqrt(segmentLine.OrigDist2());
if (IsInArcAngle(lineAngle))
{
canReturn = true;
tMax = Math.Max(tMax, centerAlong + _radius / segmentLength);
}
double reverseLineAngle = lineAngle - Math.PI;
if (IsInArcAngle(reverseLineAngle))
{
tMin = Math.Min(tMin, centerAlong - _radius / segmentLength);
if (canReturn)
{
return;
}
}
}
Pnt start = _center +
_radius * new Pnt2D(Math.Cos(StartDirection), Math.Sin(StartDirection))
- segStart;
double startOffset = SegmentUtils.GetOffset(start, segmentLine);
if (Math.Abs(startOffset) < offset)
{
double startAlong = SegmentUtils.GetAlongFraction(start, segmentLine);
tMin = Math.Min(tMin, startAlong);
tMax = Math.Max(tMax, startAlong);
}
double endDirection = StartDirection + (Angle ?? 0);
Pnt end = _center +
_radius * new Pnt2D(Math.Cos(endDirection), Math.Sin(endDirection))
- segStart;
double endOffset = SegmentUtils.GetOffset(end, segmentLine);
if (Math.Abs(endOffset) < offset)
{
double endAlong = SegmentUtils.GetAlongFraction(end, segmentLine);
tMin = Math.Min(tMin, endAlong);
tMax = Math.Max(tMax, endAlong);
}
if (_radius + offset > Math.Abs(centerOffset))
{
var segmentStarts = new List <Pnt>();
{
double segmentLength = Math.Sqrt(segmentLine.OrigDist2());
Pnt off = offset / segmentLength * new Pnt2D(-segmentLine.Y, segmentLine.X);
segmentStarts.Add(segStart + off);
segmentStarts.Add(segStart - off);
}
foreach (Pnt segmentStart in segmentStarts)
{
double tCircleMin, tCircleMax;
if (SegmentUtils.CutLineCircle(segmentStart, segmentLine, _center,
_radius * _radius,
out tCircleMin, out tCircleMax))
{
foreach (double t in new[] { tCircleMin, tCircleMax })
{
Pnt dirPnt = segmentStart + t * segmentLine - _center;
double dirAngle = Math.Atan2(dirPnt.Y, dirPnt.X);
if (IsInArcAngle(dirAngle))
{
tMin = Math.Min(tMin, t);
tMax = Math.Max(tMax, t);
}
}
}
}
}
}
