clone functions

port.lua

@@ -47,6 +47,19 @@ function Port:new(position, rotation, color)
     return port
 end
 
+---@return Port
+function Port:clone()
+    local port = {
+        position = GridPoint:new( self.position.x, self.position.y ),
+        alignment = self.alignment,
+        scanOffset = self.scanOffset,
+        color = self.color
+    }
+    setmetatable( port, { __index = self } )
+
+    return port
+end
+
 function Port:rotateClockwise()
     self.position.x, self.position.y = -self.position.y, self.position.x
     self.scanOffset = (self.scanOffset == 1) ~= self.alignment and 1 or 0