Retrieving pair indexes from a list of points for accurate parameter for shatter

I see that you started another thread on this subject:

Seems to me that you are painting yourself into needlessly complicated corners, then asking for help to get out. It’s hard to escape the idea that the basis for your lines and points are just rectangles? (white) And the super easy solution is Offset curve? (blue)

20190723_Q%26A_2019Jul24b
20190723_Q&A_2019Jul24b.gh (13.7 KB)