public Side GetSide(UniversalLine otherLine)
{
if (VisuallyClosed || otherLine.VisuallyClosed)
{
return(GetSideClosedCase(otherLine));
}
else
{
return(GetSideOpenedCase(otherLine));
}
}
private Side GetSideClosedCase(UniversalLine other)
{
Point3d getPointMaxY(UniversalLine line) =>
line.Segments
.Select(segment => segment.EndPoint)
.Aggregate(line.StartPoint, (p1, p2) => p1.Y > p2.Y ? p1 : p2);
Side GetTurnDirectionAt(UniversalLine line, Point3d point)
{
Point3d previous = default(Point3d), next = default(Point3d);
bool hasNext = false, hasPrevious = false;
foreach (var segment in Segments)
{
if (point == segment.StartPoint)
{
next = segment.EndPoint;
hasNext = true;
if (hasPrevious)
{
break;
}
}
if (point == segment.EndPoint)
{
previous = segment.StartPoint;
hasPrevious = true;
if (hasNext)
{
break;
}
}
}
if (!hasNext || !hasPrevious)
{
throw new InvalidOperationException("Bottom line is strange");
}
return(previous.GetVectorTo(point).GetSide(point.GetVectorTo(next)));
}
var pointMaxY = getPointMaxY(this);
var isOutside = pointMaxY.Y > getPointMaxY(other).Y;
var turnDirection = GetTurnDirectionAt(this, pointMaxY);
return(isOutside ? turnDirection : (Side)(-(int)turnDirection));
}
private Side GetSideOpenedCase(UniversalLine otherLine)
{
bool codirectional(UniversalLine line, UniversalLine other)
{
using (var connectedFronts = new Line(line.StartPoint, other.StartPoint))
using (var connectedEnds = new Line(line.EndPoint, other.EndPoint))
{
return(!connectedFronts.Intersects(connectedEnds, 0) &&
!line.Intersects(connectedFronts, 1) &&
!other.Intersects(connectedFronts, 1) &&
!line.Intersects(connectedEnds, 1) &&
!other.Intersects(connectedEnds, 1));
}
}
var thisSegment = Segments.First();
var otherSegment = codirectional(this, otherLine)
? otherLine.Segments.First()
: otherLine.Segments.Last();
if (thisSegment.StartPoint == otherSegment.StartPoint)
{
return(thisSegment.GetFirstDerivative(0).GetSide(otherSegment.GetFirstDerivative(0)));
}
else if (thisSegment.StartPoint == otherSegment.EndPoint)
{
return(thisSegment.GetFirstDerivative(0).GetSide(otherSegment.GetFirstDerivative(1)));
}
var tangent = thisSegment.GetFirstDerivative(thisSegment.EvaluatePoint(0));
var normal = new Vector3d(tangent.Y, -tangent.X, 0);
using (var normalLine = new Line(thisSegment.StartPoint, thisSegment.StartPoint + normal))
using (var otherLineSegment = new Line(otherSegment.StartPoint, otherSegment.EndPoint))
using (var intersection = new Point3dCollection())
{
normalLine.IntersectWith(otherLineSegment, Intersect.ExtendBoth, intersection, IntPtr.Zero, IntPtr.Zero);
if (intersection.Count == 0)
{
throw new InvalidOperationException("Top line does not intersect bottom's normal");
}
return(tangent.GetSide(thisSegment.StartPoint.GetVectorTo(intersection[0])));
}
}
public bool TryAddSegment(UniversalLine line)
{
var allowance = Segments.LastOrDefault()?.Length * 0.1 ?? 0.0;
if (!Lines.Any())
{
Lines.Add(line);
}
else if (VisuallyClosed || line.VisuallyClosed && Lines.Any())
{
return(false);
}
else if (AlmostEqual(line.EndPoint, StartPoint, allowance))
{
Lines.Insert(0, line);
}
else if (AlmostEqual(line.StartPoint, EndPoint, allowance))
{
Lines.Add(line);
}
else if (AlmostEqual(line.StartPoint, StartPoint, allowance))
{
line.Reverse();
Lines.Insert(0, line);
}
else if (AlmostEqual(line.EndPoint, EndPoint, allowance))
{
line.Reverse();
Lines.Add(line);
}
else
{
return(false);
}
return(true);
}
