This is an easy min/max system for bouncing pmpd masses in a maze / expandable.
https://patchstorage.com/pmpd-micro-platformer-pd-vanilla-pmpd-gem/

this new one has much smaller boxes https://patchstorage.com/pmpd-drawing-ball-game-pd-vanilla-gem-pmpd/

https://patchstorage.com/pmpd-xy-min-max-drawing-system-pd-vaniila-gem-pmpd/

https://patchstorage.com/pmpd-wheel-physics-pd-vanilla-gem-pmpd/

This is absolutely insane

Crazy stuff. Keep up posting those please.

really cool stuff - had fun playing around with this! now i didn't understand the whole patch (which is insane) ... but it looks like you're checking the closest "pixels" only for each mass? seems like a great optimisation so that you don't need to check against every pixel. did i get that correctly?

right each mass has a min-max system attached to it. and it looks at the pixels surrounding the current pixel,. diagonal doesnt really happen. and the location of the mass point has the interger lines skipped.