ProcessOffset problem #10

Hi, i am trying to convert your python code to javascript, and result in weird path data.

I enlarge the sample path and offset is 4
paths = [[[0,0],[20,0],[20,20],[0,20],[0,0]]]

I try copy the python data result also the result is like that.

Here's my code
Gist code

I am planning to make a GCODE CNC generator from SVG, with tool offseting.

Thx