feat: Turtle.get_Marker ( Fixes #227 )

Author: StartAutomating

Types/Turtle/get_Marker.ps1

@@ -0,0 +1,43 @@
+<#
+.SYNOPSIS
+    Gets the turtle as a Marker
+.DESCRIPTION
+    Gets the Turtle as a `<marker>`, which can mark points on another shape.
+.EXAMPLE
+    turtle viewbox 200 teleport 0 100 forward 100 markerEnd (
+        turtle viewbox 10 rotate -90 polygon 10 3 fill context-fill stroke context-stroke
+    ) strokewidth '3%' save ./marker.svg
+.LINK
+    https://developer.mozilla.org/en-US/docs/Web/SVG/Reference/Element/marker
+#>
+param()
+
+# The default settings for markers
+$markerAttributes = [Ordered]@{
+    id="$($this.id)-marker"
+    viewBox="$($this.ViewBox)"
+    orient='auto-start-reverse'
+    refX=0
+    refY=$this.Height/2
+    markerWidth=5 
+    marketHeight=5
+}
+# Marker attributes can exist in .Attribute or .SVGAttribute
+$prefix = [Regex]::new('^/?marker/', 'IgnoreCase')
+foreach ($collection in $this.Attribute, $this.SVGAttribute) {
+    foreach ($key in $collection.Keys) {
+        if ($key -notmatch $prefix) { continue }
+        $markerAttributes[$key -replace $prefix] = $collection[$key]
+    }
+}
+
+# Create a marker XML.
+[xml]@(
+    "<marker$(
+    foreach ($key in $markerAttributes.Keys) {
+        " $key='$($markerAttributes[$key])'"
+    }
+)>"
+    $this.SVG.SVG.InnerXML
+"</marker>"
+)