Drawing - Double Lines

Sep 2 at 7:31 PM
I'm sure this has been asked before but I cant seem to find it, so thank you so much in advance.

If I want to draw all the triangles myself, I can easily loop though each one and draw all three sides.

However, I'm obviously redrawing lines twice since a single line could belong to two triangles. Is there a list that is just a list of the triangle lines but not repeated? Or a easy/fast bit of code for this?

Thanks in advance, and this is a great piece of code. You work and effort and MUCH appreciated!
Sep 2 at 7:51 PM
Take a look at