/// <summary>
/// Checks to see of this point touches the two points of a segment or the line between them.
/// </summary>
/// <param name="Sgmt">A LineSegment representing the line segment to check</param>
/// <returns>True if the point and line segment intersect</returns>
public bool Intersects(LineSegment Sgmt)
{
// prevent redundant code and simply use the segemnt
if (Sgmt.Intersects(this))
{
return(true);
}
return(false);
}
/// <summary>
/// Checks whether the borders of a polygon shape, lines of line shapes, or points of point shapes touch.
/// </summary>
/// <param name="Shape1">A MapWinGIS.Shape object to test</param>
/// <param name="Shape2">A MapWinGIS.Shape object to test</param>
/// <returns>True if the boundaries touch</returns>
public static bool ShapeBoundariesTouch(MapWinGIS.Shape Shape1, MapWinGIS.Shape Shape2)
{
if (Shape1 == null || Shape1.ShapeType == MapWinGIS.ShpfileType.SHP_NULLSHAPE)
{
throw new ArgumentException("Argument Shape1 cannot be null");
}
if (Shape2 == null || Shape2.ShapeType == MapWinGIS.ShpfileType.SHP_NULLSHAPE)
{
throw new ArgumentException("Argument Shape2 cannot be null");
}
if (Shape1.ShapeType == MapWinGIS.ShpfileType.SHP_MULTIPATCH)
{
throw new ArgumentException("Multipatch is not supported");
}
if (Shape2.ShapeType == MapWinGIS.ShpfileType.SHP_MULTIPATCH)
{
throw new ArgumentException("Multipatch is not supported");
}
ShapeCategories Typ1, Typ2;
Typ1 = GetCategory(Shape1);
Typ2 = GetCategory(Shape2);
// for single points, simply show if these specific points overlap
if (Typ1 == ShapeCategories.Point &&
Typ2 == ShapeCategories.Point)
{
Point p1 = new Point(Shape1.get_Point(0));
Point p2 = new Point(Shape2.get_Point(0));
if (p1.Intersects(p2))
{
return(true);
}
return(false);
}
// Point to Non-point
if (Typ1 == ShapeCategories.Point)
{
Point p1 = new Point(Shape1.get_Point(0));
if (Typ2 == ShapeCategories.MultiPoint)
{
for (int I = 0; I < Shape2.numPoints; I++)
{
Point p2 = new Point(Shape2.get_Point(I));
if (p1.Intersects(p2))
{
return(true);
}
}
return(false);
}
else
{
for (int I = 0; I < Shape2.numPoints - 1; I++)
{
LineSegment seg = new LineSegment(Shape2.get_Point(I), Shape2.get_Point(I + 1));
if (seg.Intersects(p1))
{
return(true);
}
}
return(false);
}
}
// Point2 to non-point
if (Typ2 == ShapeCategories.Point)
{
Point p2 = new Point(Shape2.get_Point(0));
if (Typ1 == ShapeCategories.MultiPoint)
{
for (int I = 0; I < Shape1.numPoints; I++)
{
Point p1 = new Point(Shape1.get_Point(I));
if (p2.Intersects(p1))
{
return(true);
}
}
return(false);
}
else
{
for (int I = 0; I < Shape1.numPoints - 1; I++)
{
LineSegment seg = new LineSegment(Shape1.get_Point(I), Shape1.get_Point(I + 1));
if (seg.Intersects(p2))
{
return(true);
}
}
return(false);
}
}
// for multipoint, test every point for intersection.
if (Typ1 == ShapeCategories.MultiPoint &&
Typ2 == ShapeCategories.MultiPoint)
{
List <int> Points1 = PointsWithinEnvelope(Shape1, Shape2.Extents);
List <int> Points2 = PointsWithinEnvelope(Shape2, Shape1.Extents);
for (int I = 0; I < Points1.Count; I++)
{
for (int J = 0; J < Points2.Count; J++)
{
Point p1 = new Point(Shape1.get_Point(I));
Point p2 = new Point(Shape2.get_Point(J));
if (p1.Intersects(p2))
{
return(true);
}
}
}
return(false);
}
// For lines and polygons simply test line segments in the area of interrest to see if they touch
// (touching in this case just equates to having a minimum distance of 0.
if ((Typ1 == ShapeCategories.Line || Typ1 == ShapeCategories.Polygon) &&
(Typ2 == ShapeCategories.Line || Typ2 == ShapeCategories.Polygon))
{
List <LineSegment> Segs1 = LineSegmentsWithinEnvelope(Shape1, Shape2.Extents);
List <LineSegment> Segs2 = LineSegmentsWithinEnvelope(Shape2, Shape1.Extents);
for (int I = 0; I < Segs1.Count; I++)
{
for (int J = 0; J < Segs2.Count; J++)
{
if (Segs1[I].Intersects(Segs2[J]))
{
return(true);
}
}
}
return(false);
}
// multi-point to polygon
if (Typ1 == ShapeCategories.MultiPoint)
{
List <int> Points1 = PointsWithinEnvelope(Shape1, Shape2.Extents);
List <LineSegment> Segs2 = LineSegmentsWithinEnvelope(Shape2, Shape1.Extents);
for (int I = 0; I < Points1.Count; I++)
{
for (int J = 0; J < Segs2.Count; J++)
{
if (Segs2[J].Intersects(Shape1.get_Point(Points1[I])))
{
return(true);
}
}
}
return(false);
}
if (Typ2 == ShapeCategories.MultiPoint)
{
List <int> Points2 = PointsWithinEnvelope(Shape2, Shape1.Extents);
List <LineSegment> Segs1 = LineSegmentsWithinEnvelope(Shape1, Shape2.Extents);
for (int I = 0; I < Points2.Count; I++)
{
for (int J = 0; J < Segs1.Count; J++)
{
if (Segs1[J].Intersects(Shape2.get_Point(Points2[I])))
{
return(true);
}
}
}
return(false);
}
return(false);
}