feat: Turtle.StepSpiral ( Fixes #122 )

Author: StartAutomating

Types/Turtle/StepSpiral.ps1

@@ -0,0 +1,44 @@
+<#
+.SYNOPSIS
+    Draws a step spiral
+.DESCRIPTION
+    Draws a spiral as a series of steps.
+
+    Each step will draw a line, rotate, and increment the length of the next step.
+
+    By default, this creates an outward spiral.
+
+    To create an inward spiral, use a negative StepSize or StepCount.
+#>
+param(
+# The length of the first step
+[double]$Length = 1,
+# The angle to rotate after each step
+[double]$Angle = 90,
+# The amount of change per step
+[double]$StepSize = 1,
+# The number of steps.
+[int]$StepCount = 20
+)
+
+# If the step size or count is negative
+if (
+    ($stepSize -lt 0 -or $stepCount -lt 0) -and
+    $Length -in 0,1 # and the length is either the default or zero
+) {
+    # set the length to the correct maximim step size, so we can make an inward spiral.
+    $Length = ([Math]::Abs($stepSize) * [Math]::Abs($stepCount))
+} 
+elseif ($length -eq 0) {
+    # If the length is empty, default it to the step size
+    $Length = $StepSize
+}
+
+# Perform the appropriate steps
+foreach ($n in 1..([Math]::Abs($StepCount))) {
+    $this = $this.Forward($length).Rotate($angle)
+    $length += $stepSize    
+}
+# and return ourself.
+return $this
+