Modify for 52x52 LED Panel


First, I really appreciate your great work!

Second, I recently grabbed a LED Panel from the dumpster which has 52x52 pixels on there. I hooked it up like the HUB75 panels, but the mapping seems not to be right.
I need to skip 3 pixels every 13 horzontal pixels.
The shift register they used has 16outputs, but they left 3 outputs unconnected to have 52pixels in total. (same as in vertical rows, but I could easily change that in the code from 16 to 13)
what lines do I need to add/modify?

backgroundLayer.drawLine(63, 0, 0, 31, white);
backgroundLayer.drawLine(63, 31, 0, 0, white);