/// <summary> /// Draw the 2-point stencil drag points /// </summary> /// <param name="e">the canvas</param> /// <param name="zoomFactor">the zoom factor</param> public void Draw(SKCanvas e, float zoomFactor) { if (e == null) { throw new ArgumentNullException(nameof(e)); } if (zoomFactor <= 0) { throw new ArgumentOutOfRangeException(nameof(zoomFactor), $"zoomFactor cannot be less than or equal to 0: {zoomFactor}."); } using var paint2 = new SKPaint { Color = Color.Red.ToSKColor().WithAlpha(128), IsStroke = false, }; e.DrawCircle(Point1.ToSKPoint(), Radius / zoomFactor, paint2); e.DrawCircle(Point2.ToSKPoint(), Radius / zoomFactor, paint2); }