public Polygon RectangleInside()
{
var p1 = Vector2.zero;
var p2 = Vector2.zero;
var maxLength = float.MinValue;
ForEachEdge((a, b, i) =>
{
var len = (a - b).magnitude;
if (len > maxLength)
{
p1 = a;
p2 = b;
maxLength = len;
}
});
var rotated = Rotate(GeometryHelpers.Angle(p1 - p2));
var minY = rotated.Vertices.Min(v => v.y);
var greatestDistance = rotated.Vertices.Max(v => v.y - minY);
var normal = GeometryHelpers.Rotate90(p2 - p1).normalized;
var newHouse = new Polygon(p1, p2, p2 - GeometryHelpers.Scale(normal, greatestDistance),
p1 - GeometryHelpers.Scale(normal, greatestDistance)).ZoomShrink(0.2f);
newHouse = newHouse.Translate(newHouse.Center - Center);
return(newHouse);
}
public Polygon Peel(Vector2 v1, float amount)
{
var v2 = GetNextVertex(v1);
var n = GeometryHelpers.Scale(GeometryHelpers.Normalize(GeometryHelpers.Rotate90(v2 - v1)), amount);
return(Cut(v1 + n, v2 + n, 0).First());
}
public Polygon Shrink(IList <float> shrinkAmounts)
{
var newPoly = new Polygon(this);
ForEachEdge((p1, p2, index) =>
{
var amount = shrinkAmounts[index];
if (amount > 0)
{
var n = GeometryHelpers.Scale(GeometryHelpers.Normalize(GeometryHelpers.Rotate90(p2 - p1)), amount);
newPoly = newPoly.Cut(p1 + n, p2 + n, 0).First();
}
});
return(newPoly);
}
public Polygon Buffer(IList <float> shrinkAmounts)
{
var newPoly = new Polygon();
ForEachEdge((p1, p2, index) =>
{
var amount = shrinkAmounts[index];
if (amount <= 0.01)
{
newPoly.Vertices.Add(p1);
newPoly.Vertices.Add(p2);
}
else
{
var n = GeometryHelpers.Scale(GeometryHelpers.Normalize(GeometryHelpers.Rotate90(p2 - p1)), amount);
newPoly.Vertices.Add(p1 + n);
newPoly.Vertices.Add(p2 + n);
}
});
bool wasCut;
var lastEdge = 0;
do
{
wasCut = false;
var n = newPoly.Vertices.Count;
for (var i = lastEdge; i < n - 2; i++)
{
lastEdge = i;
var p11 = newPoly.Vertices[i];
var p12 = newPoly.Vertices[i + 1];
var x1 = p11.x;
var y1 = p11.y;
var dx1 = p12.x - x1;
var dy1 = p12.y - y1;
var maxJ = i > 0 ? n : n - 1;
for (var j = i + 2; j < maxJ; j++)
{
var p21 = newPoly.Vertices[j];
var p22 = j < n - 1 ? newPoly.Vertices[j + 1] : newPoly.Vertices[0];
var x2 = p21.x;
var y2 = p21.y;
var dx2 = p22.x - x2;
var dy2 = p22.y - y2;
var intersect = GeometryHelpers.IntersectLines(x1, y1, dx1, dy1, x2, y2, dx2, dy2);
if (intersect.x > Delta && intersect.x < (1 - Delta) && intersect.y > Delta && intersect.y < (1 - Delta))
{
var pn = new Vector2(x1 + dx1 * intersect.x, y1 + dy1 * intersect.x);
newPoly.Vertices.Insert(j + 1, pn);
newPoly.Vertices.Insert(i + 1, pn);
wasCut = true;
break;
}
}
}
} while (wasCut);
var regular = Enumerable.Range(0, newPoly.Vertices.Count).ToList();
Polygon bestPart = null;
var bestPartSq = float.MinValue;
while (regular.Count > 0)
{
var indices = new List <int> ();
var start = regular[0];
var i = start;
do
{
indices.Add(i);
regular.Remove(i);
var next = (i + 1) % newPoly.Vertices.Count;
var v = newPoly.Vertices[next];
var next1 = newPoly.Vertices.IndexOf(v);
if (next1 == next)
{
next1 = newPoly.Vertices.LastIndexOf(v);
}
i = next1 == -1 ? next : next1;
} while (i != start && indices.Count < 1000);
if (indices.Count >= 999)
{
indices = indices.Take(4).ToList();
}
var poly = new Polygon(indices.Select(v => newPoly.Vertices[v]));
var s = poly.Area();
if (s > bestPartSq)
{
bestPart = poly;
bestPartSq = s;
}
}
return(bestPart);
}
