feat: Turtle.SierpinskiSquareCurve ( Fixes PoshWeb#41 )

Author: James Brundage

Types/Turtle/SierpinskiSquareCurve.ps1

@@ -0,0 +1,34 @@
+<#
+.SYNOPSIS
+    Generates a Sierpinski Square Curve.
+.DESCRIPTION
+    Generates a Sierpinski Square Curve using turtle graphics.
+.LINK
+    https://en.wikipedia.org/wiki/Sierpi%C5%84ski_curve#Representation_as_Lindenmayer_system
+.EXAMPLE
+    $turtle.SierpinskiSquareCurve().Pattern.Save("$pwd/SierpinskiSquareCurve.svg")
+.EXAMPLE
+    $turtle.Clear()
+    $turtle.SierpinskiSquareCurve(10,4)
+    $turtle.PatternTransform = @{
+        'scale' = 0.9        
+    }    
+    $turtle.PatternAnimation = "
+    <animateTransform attributeName='patternTransform' attributeType='XML' type='scale' values='1;0.9;1' dur='19s' repeatCount='indefinite' additive='sum' />
+    <animateTransform attributeName='patternTransform' attributeType='XML' type='skewY' values='0;-30;30;-30;0' dur='67s' repeatCount='indefinite' additive='sum' />
+    <animateTransform attributeName='patternTransform' attributeType='XML' type='skewX' values='0;-30;30;-30;0' dur='83s' repeatCount='indefinite' additive='sum' />
+    "
+    $turtle.Pattern.Save("$pwd/SierpinskiSquareCurve2.svg")
+#>
+param(
+    [double]$Size = 20,
+    [int]$Order = 5,
+    [double]$Angle = 90
+)
+return $this.L('X',  [Ordered]@{
+    X = 'XF-F+F-XF+F+XF-F+F-X'
+}, $Order, [Ordered]@{
+    '\+'    = { $this.Rotate($Angle) }
+    '-'     = { $this.Rotate($Angle * -1) }
+    '[FG]'  = { $this.Forward($Size) }
+})