satin stitch 

I wrote that project to import it to turtlestitch.org (snap! based) which generates output for my embroidery machine.
Think about sewing when looking at the code. The line needs to be drawn in small single steps. 3-8 as an input for the "width" in my block" satin stitch density" is a good value.
To use it:
move the mouse to the stage and press "space" and then start drawing.
Press "s" to stop drawing
Press "space" to continue again for another separted line.
Press "n" to clear the stage and start again.