/// <summary>
/// Test the intersection with a shape range.
/// </summary>
/// <param name="shape">The shape to do intersection calculations with.</param>
/// <returns>True, if both intersect.</returns>
public bool Intersects(ShapeRange shape)
{
// Extent check first. If the extents don't intersect, then this doesn't intersect.
if (!Extent.Intersects(shape.Extent))
{
return(false);
}
switch (FeatureType)
{
case FeatureType.Polygon:
PolygonShape.Epsilon = Epsilon;
return(PolygonShape.Intersects(this, shape));
case FeatureType.Line:
LineShape.Epsilon = Epsilon;
return(LineShape.Intersects(this, shape));
case FeatureType.Point:
PointShape.Epsilon = Epsilon;
return(PointShape.Intersects(this, shape));
default: return(false);
}
}
/// <summary>
/// Calculates the intersection of a polygon shape without relying on the NTS geometry
/// </summary>
/// <param name="polygonShape"></param>
/// <param name="otherShape"></param>
/// <returns></returns>
public static bool Intersects(ShapeRange polygonShape, ShapeRange otherShape)
{
if (polygonShape.FeatureType != FeatureType.Polygon)
{
throw new ArgumentException("The First parameter should be a point shape, but it was featuretype:" + polygonShape.FeatureType);
}
// Extents will have already been tested by this point.
// Regardless of what the other shapetype is, a coordinate inside this polygon indicates a hit.
if (ContainsVertex(polygonShape, otherShape))
{
return(true);
}
// There is no other way for this polygon to intersect the other points
if (otherShape.FeatureType == FeatureType.Point || otherShape.FeatureType == FeatureType.MultiPoint)
{
return(false);
}
// For lines and polygons, if any segment intersects any segment of this polygon shape, return true.
// This is essentially looking for the rare case of crossing in and crossing out again with
// no actual points inside this polygonShape.
if (LineShape.SegmentsIntersect(polygonShape, otherShape))
{
return(true);
}
// There is no other way for this polygon to intersect the other lines
if (otherShape.FeatureType == FeatureType.Line)
{
return(false);
}
// If the other polygon completely contains this polygon every other test has returned false,
// but this will test for that case with only a single point.
Vertex v = polygonShape.First();
ShapeRange onlyFirstPoint = new ShapeRange(v);
return(ContainsVertex(otherShape, onlyFirstPoint));
}