fix: Turtle.Star() even point fix ( Fixes #190 )

Author: StartAutomating

Turtle.types.ps1xml

@@ -1848,20 +1848,43 @@ return $this
 .DESCRIPTION
     Draws a star pattern with turtle graphics.
 .EXAMPLE
-    $turtle = New-Turtle
-    $turtle.Star().Pattern.Save("$pwd/Star.svg")
+    turtle star 42 
+.EXAMPLE
+    turtle star 42 20
+.EXAMPLE
+    turtle star 42 20 @('rotate', (360/20*2), 'star', 42, 20 * 10) save ./StarFlower20.svg
 .EXAMPLE
-    Move-Turtle Star | Save-Turtle "./Star.svg"
+    turtle star 42 20 @('rotate', (360/20*2), 'star', 42, 20 * 10) morph @(
+        turtle star 42 20 @('rotate', (360/20*2), 'star', 42, 20 * 10)
+        turtle star 42 20 @('rotate', (360/20*26), 'star', 42, 20 * 10)
+        turtle star 42 20 @('rotate', (360/20*2), 'star', 42, 20 * 10)        
+    ) save ./StarFlower20Morph.svg
+.EXAMPLE
+    turtle star 42 20 @('rotate', (360/20*18), 'star', 42, 20 * 10) save ./StarFlower-20-18.svg
 #>
 param(
+    # The approximate size of the star
     [double]$Size = 50,
-    [int]$Points = 5
+    # The number of points in the star
+    [int]$Points = 6
 )
-$Angle = 180 - (180 / $Points)
-foreach ($n in 1..$Points) {
-    $this.Forward($Size)
-    $this.Rotate($Angle)
-}
+
+# To determine the angle, divide 360 by the number of points
+$angle = 360 / $Points
+
+$SegmentLength = ($Size*2)/$Points
+# Each 'point' in the star actually consists of two points, an inward and outward point.
+# Imagine we start an an outward point
+$null = foreach ($n in 1..([Math]::Abs($Points))) {
+    $this. # We rotate by the angle and move forward one segment
+        Rotate($Angle).Forward($SegmentLength).
+        # The rotate back and move forward another segment
+        Rotate(-$angle).Forward($SegmentLength).
+        # then rotate once more so we continue moving around the circle
+        Rotate($angle)
+} # we repeat this up to the number of points in order to draw a star with no crossings.
+
+return $this
 
                     </Script>
       </ScriptMethod>