public Polygon TwoPieces(Polygon polygon1, Polygon polygon2, LineString line1, LineString line2)
{
if (polygon1.Intersects(polygon2) || polygon1.Touches(polygon2))
{
return polygon1.Union(polygon2) as Polygon;
}
else
{
var pg = GetConvexHull(line1, line2);
return pg.Union(polygon1).Union(polygon2) as Polygon;
}
}
/// <summary>
/// Takes an array of simple polygons and combines them into one multi-part shape.
/// </summary>
/// <param name="parts">The array of polygons.</param>
/// <param name="resultShp">The resulting multi-part shape.</param>
public static void CombineParts(ref IFeature[] parts, ref IFeature resultShp)
{
int numParts = parts.Length;
Polygon po = new Polygon(parts[0].Coordinates);
Polygon poly;
for (int i = 0; i <= numParts - 1; i++)
{
poly = new Polygon(parts[i].Coordinates);
po = poly.Union(po) as Polygon;
}
resultShp = new Feature(po);
}
/// <summary>
/// 1.將多邊形內部的小碎地(小於1平方公尺)移除
/// </summary>
/// <param name="polygon"></param>
public Polygon CleanupPolygon(Polygon polygon)
{
if (polygon.Holes.Any(x => x.Envelope.Area() < 1))
{
polygon = new Polygon(polygon.ExteriorRing.Coordinates);
var holes = polygon.Holes.Where(x => x.Envelope.Area() > 1);
foreach (var hole in holes)
{
polygon.Union(new Polygon(hole.Coordinates));
}
}
return polygon;
}
