private double ClippedArea()
{
if (this.Voids == null || this.Voids.Count == 0)
{
return(this.Perimeter.Area());
}
var clipper = new ClipperLib.Clipper();
var normal = Perimeter.Normal();
if (normal.IsAlmostEqualTo(Vector3.ZAxis))
{
clipper.AddPath(Perimeter.ToClipperPath(), ClipperLib.PolyType.ptSubject, true);
clipper.AddPaths(this.Voids.Select(p => p.ToClipperPath()).ToList(), ClipperLib.PolyType.ptClip, true);
}
else
{
var transform = new Transform(Perimeter.Start, normal);
transform.Invert();
var perimeter = Perimeter.TransformedPolygon(transform);
clipper.AddPath(perimeter.ToClipperPath(), ClipperLib.PolyType.ptSubject, true);
clipper.AddPaths(this.Voids.Select(p => p.TransformedPolygon(transform).ToClipperPath()).ToList(), ClipperLib.PolyType.ptClip, true);
}
var solution = new List <List <ClipperLib.IntPoint> >();
clipper.Execute(ClipperLib.ClipType.ctDifference, solution, ClipperLib.PolyFillType.pftEvenOdd);
return(solution.Sum(s => ClipperLib.Clipper.Area(s)) / Math.Pow(1.0 / Vector3.EPSILON, 2));
}
/// <summary>
/// Ensure that voids run in an opposite winding direction to the perimeter of the profile.
/// Be sure to call this if you modify the Profile's Voids array directly.
/// </summary>
public void OrientVoids()
{
// This should only occur in the case of a parametric
// profile which defines its own perimeter and void logic
// during construction.
if (Perimeter == null || Voids == null)
{
return;
}
var correctedVoids = new List <Polygon>();
var perimeterNormal = Perimeter.Normal();
foreach (var voidCrv in Voids)
{
if (voidCrv.Normal().Dot(perimeterNormal) > 0)
{
correctedVoids.Add(voidCrv.Reversed());
}
else
{
correctedVoids.Add(voidCrv);
}
}
this.Voids = correctedVoids;
}
/// <summary>
/// Ensure that voids run in an opposite winding direction to the perimeter of the profile.
/// Be sure to call this if you modify the Profile's Voids array directly.
/// </summary>
public void OrientVoids()
{
var correctedVoids = new List <Polygon>();
var perimeterNormal = Perimeter.Normal();
foreach (var voidCrv in Voids)
{
if (voidCrv.Normal().Dot(perimeterNormal) > 0)
{
correctedVoids.Add(voidCrv.Reversed());
}
else
{
correctedVoids.Add(voidCrv);
}
}
this.Voids = correctedVoids;
}
