/// <summary>
/// Attempts to scale up a Polygon until coming within the tolerance percentage of the target area.
/// </summary>
/// <param name="polygon">Polygon to scale.</param>
/// <param name="area">Target area of the Polygon.</param>
/// <param name="tolerance">Area total tolerance.</param>
/// <param name="origin">Alignment location for final Polygon.</param>
/// <param name="within">Polygon acting as a constraining outer boundary.</param>
/// <param name="among">List of Polygons to avoid intersecting.</param>
/// <returns>
/// A new Polygon.
/// </returns>
public static Polygon ExpandToArea(this Polygon polygon, double area, double ratio,
double tolerance = 0.1, Orient origin = Orient.C,
Polygon within = null, List <Polygon> among = null)
{
if (polygon.IsClockWise())
{
polygon = polygon.Reversed();
}
if (Math.Abs(polygon.Area() - area) <= Math.Abs(tolerance * area))
{
return(polygon);
}
var position = polygon.Compass().PointBy(origin);
Polygon tryPoly = Shaper.RectangleByArea(area, ratio);
tryPoly = tryPoly.MoveFromTo(tryPoly.Compass().PointBy(origin), position);
double tryArea = tryPoly.Area();
do
{
var t = new Transform();
t.Scale(tryArea / area, tryPoly.Compass().PointBy(origin));
tryPoly = tryPoly.TransformedPolygon(t);
if (within != null && tryPoly.Intersects(within))
{
var tryPolys = within.Intersection(tryPoly);
if (tryPolys != null && tryPolys.Count > 0)
{
tryPoly = tryPolys.First();
}
}
if (among != null && tryPoly.Intersects(among))
{
var tryPolys = Shaper.Differences(tryPoly.ToList(), among);
if (tryPolys != null && tryPolys.Count > 0)
{
tryPoly = tryPolys.First();
}
}
tryArea = tryPoly.Area();
}while (!Shaper.NearEqual(tryPoly.Area(), area, tolerance * area) &&
!Shaper.NearEqual(tryPoly.Area(), tryArea, tolerance));
return(tryPoly);
}
/// <summary>
/// Creates the largest Polygon fitted to supplied intersecting Polygons.
/// </summary>
/// <param name="among">List of Polygons against which this Polygon must conform.</param>
/// <returns>
/// A new Polygon.
/// </returns>
public static Polygon FitAmong(this Polygon polygon, List <Polygon> among)
{
if (among == null || among.Count == 0)
{
return(polygon);
}
var polygons = Shaper.Differences(polygon.ToList(), among);
if (polygons.Count == 0)
{
return(null);
}
polygon = polygons.OrderByDescending(p => Math.Abs(p.Area())).First();
if (polygon.IsClockWise())
{
return(polygon.Reversed());
}
return(polygon);
}
