Added Squircle

src/Comet/Shapes/Squircle.cs

@@ -0,0 +1,61 @@
+using System;
+using Rectangle = Microsoft.Maui.Graphics.Rectangle;
+
+namespace Comet;
+
+public class Squircle : Shape
+{
+	private readonly float cornerRadius;
+
+	public Squircle(float cornerRadius)
+	{
+		this.cornerRadius = cornerRadius;
+	}
+
+	public float CornerRadius => cornerRadius;
+	const float SquircleFactor = 1.125f;
+	const float ControlPointFactor = 46f / 64f;
+	public override PathF PathForBounds(Microsoft.Maui.Graphics.Rectangle rect)
+	{
+		var x = (float)rect.X;
+		var y = (float)rect.Y;
+		var w = (float)rect.Width;
+		var h = (float)rect.Height;
+		var path = new PathF();
+		var adjustedRadius = cornerRadius * SquircleFactor;
+		adjustedRadius = Math.Min(adjustedRadius, Math.Min(w, h) / 2);
+		var controlPointOffset = adjustedRadius * ControlPointFactor;
+
+		var x1 = x + adjustedRadius;
+		var x3 = x + w;
+		var x2 = x3 - adjustedRadius;
+
+		var y1 = y + adjustedRadius;
+		var y3 = y + h;
+		var y2 = y3 - adjustedRadius;
+
+		path.MoveTo(x1, y);
+		path.LineTo(x2, y);
+		path.CurveTo(
+			x2 + controlPointOffset, y,
+			x3, y1 - controlPointOffset,
+			x3, y1);
+		path.LineTo(x3, y2);
+		path.CurveTo(
+			x3, y2 + controlPointOffset,
+			x2 + controlPointOffset, y3,
+			x2, y3);
+		path.LineTo(x1, y3);
+		path.CurveTo(
+			x1 - controlPointOffset, y3,
+			x, y2 + controlPointOffset,
+			x, y2);
+		path.LineTo(x, y1);
+		path.CurveTo(
+			x, y1 - controlPointOffset,
+			x1 - controlPointOffset, y,
+			x1, y);
+		path.Close();
+		return path;
+	}
+}