internal bool Intersects(Point2 p, bool guaranteeEdge)
{
var lastIndex = _pointList.Count - 1;
if (2 <= lastIndex)
{
var intersectionCount = IntersectionPositiveXRayCount(p);
if (intersectionCount > 0)
{
return(((_hole.HasValue && _hole.Value) ? 0 : 1) == (intersectionCount % 2));
}
if ((_hole.HasValue && _hole.Value))
{
return(true);
}
if (guaranteeEdge)
{
for (int i = lastIndex, nextIndex = 0; nextIndex <= lastIndex; i = nextIndex++)
{
if (Segment2.Intersects(_pointList[i], _pointList[nextIndex], p))
{
return(true);
}
}
}
return(false);
}
return(
0 == lastIndex
? _pointList[0].Equals(p)
: 1 == lastIndex && Segment2.Intersects(_pointList[0], _pointList[1], p)
);
}
/// <inheritdoc/>
public bool Intersects(Segment2 other)
{
if (Count == 0 || ReferenceEquals(null, other))
{
return(false);
}
if (Count == 1)
{
return(other.Intersects(this[0]));
}
throw new NotImplementedException();
}
/// <summary>
/// Determines if a point intersects this line string.
/// </summary>
/// <param name="p">A point to test intersection with.</param>
/// <returns>True when a point intersects this line string.</returns>
public bool Intersects(Point2 p)
{
var lastIndex = Count - 1;
if (lastIndex >= 1)
{
for (int i = 0, nextIndex = 1; i < lastIndex; i = nextIndex++)
{
if (Segment2.Intersects(this[i], this[nextIndex], p))
{
return(true);
}
}
}
return(lastIndex == 0 && this[0].Equals(p));
}
/// <summary>
/// Advanced intersection testing.
/// </summary>
/// <param name="p"></param>
/// <returns>0 for boundary, 1 for within, -1 for outside</returns>
internal int AdvancedIntersectionTest(Point2 p)
{
var mbr = GetMbr();
Contract.Assume(Count <= 0 || mbr != null);
if (Count >= 2 && mbr.Intersects(p))
{
var b = this[Count - 1];
for (var nextIndex = 0; nextIndex < Count; nextIndex++)
{
var a = b;
b = this[nextIndex];
if (Segment2.Intersects(a, b, p))
{
return(0);
}
}
}
return(Intersects(p, false) ? 1 : -1);
}
