internal List <Polygon> Cut(Vector v1, Vector v2, double cutRadius)
{
var clone = new Polygon(this);
Vector.MarkDefault = VectorMark.Selected;
int numberOfIntersections = 0;
for (int i = 0; i < Vertices.Count; i++)
{
Vector isectPoint = GeometryUtils.GetIntersectionPoint(this[i], this[i + 1], v1, v2);
if ((object)isectPoint != null)
{
clone.InsertIntersection(isectPoint, Constants.Tolerance);
numberOfIntersections++;
}
}
Vector.MarkDefault = VectorMark.None;
if (numberOfIntersections % 2 == 0 && numberOfIntersections > 0)
{
var result = new List <Polygon> {
new Polygon()
};
int k = 0;
bool isBeginning = true;
while (k != clone.Count)
{
if (clone.Vertices[k].Mark == VectorMark.Selected)
{
Vector cutVector = clone[k + 1] - clone[k - 1];
cutVector /= cutVector.Length;
var angleAbs = Math.Abs(cutVector.AngleBetween(v2 - v1));
if (angleAbs < Constants.Tolerance)
{
return(null);
}
cutVector *= cutRadius / Math.Sin(angleAbs * Constants.DegToRad);
double distance1 = (clone[k + 1] - clone[k]).Length;
double distance2 = (clone[k] - clone[k - 1]).Length;
if (cutVector.Length > Math.Min(distance1, distance2))
{
cutVector = cutVector / cutVector.Length * Math.Min(distance1, distance2) / 2;
}
if (!isBeginning)
{
result[result.Count - 1].Add(clone.Vertices[k] - cutVector);
result[0].Add(clone.Vertices[k] + cutVector);
}
else
{
result.Add(new Polygon());
result[result.Count - 1].Add(clone.Vertices[k] + cutVector);
result[0].Add(clone.Vertices[k] - cutVector);
}
isBeginning = !isBeginning;
}
else
{
if (isBeginning)
{
result[0].Add(clone.Vertices[k]);
}
else
{
result[result.Count - 1].Add(clone.Vertices[k]);
}
}
k++;
}
result.ForEach(p => p.IsGrass = IsGrass);
return(result.Any(polygon => polygon.Count < 3) ? null : result);
}
return(null);
}