private void _ComputeIntersections()
{
for (int i = 0; i < _clip.NumberOfVertices; ++i)
{
for (int j = 0; j < _subject.NumberOfVertices; ++j)
{
SegmentIntersectionInfo SegmentIntersectionInfo = _clip._GetSide(i)
.GetIntersectionWith(_subject._GetSide(j));
if (SegmentIntersectionInfo.Point.HasValue)
{
PointD p = SegmentIntersectionInfo.Point.Value;
_clipPoints[i].Add(new PolygonIntersectionPoint(p));
_subjectPoints[j].Add(new PolygonIntersectionPoint(p));
}
}
}
}
public bool Contains(PointD p)
{
if (this.HasOnSide(p))
{
return(true);
}
double maxX = _polygon._vertexManager.Vertices.Max(v => v.Location.X);
Segment horizontalLine = new Segment(p, new PointD(maxX + 5, p.Y));
int cnt = 0, inc = 1;
for (int i = 0; i < _polygon.NumberOfVertices; i += inc)
{
SegmentIntersectionInfo intersectionInfo = _polygon._GetSide(i)
.GetIntersectionWith(horizontalLine);
switch (intersectionInfo.Type)
{
case IntersectionType.Touches:
int nextInd = (i + 1) % _polygon.NumberOfVertices;
int prevInd = (i - 1 + _polygon.NumberOfVertices) % _polygon.NumberOfVertices;
if (_polygon._GetSide(nextInd).GetIntersectionWith(horizontalLine).Type
== IntersectionType.Covers)
{
inc = 3;
cnt += _GetIncrementationForSideCoveringCase(i + 1, horizontalLine);
}
else if (_polygon._GetSide(prevInd).GetIntersectionWith(horizontalLine).Type
== IntersectionType.Covers)
{
inc = 1;
cnt += _GetIncrementationForSideCoveringCase(i - 1, horizontalLine);
}
else
{
PointD touchPoint = intersectionInfo.Point.Value;
inc = (touchPoint == _polygon._vertexManager.GetVertex(i).Location ? 1
: 2);
cnt += _GetIncrementationForVertexTouchingCase(i, touchPoint, horizontalLine);
}
break;
case IntersectionType.Covers:
inc = 2;
cnt += _GetIncrementationForSideCoveringCase(i, horizontalLine);
break;
case IntersectionType.Intersects:
cnt += 1;
inc = 1;
break;
default: // no intersection
inc = 1;
break;
}
}
return(cnt % 2 == 0 ? false
: true);
}
