Various folks have disassembled the Asteroids arcade ROM. This was helpful recently when I wondered how collision detection was implemented. It turns out to be a sort of axis-aligned octagon intersection algorithm that was easy to implement with just a few adds, subtracts, & compares (6502 doesn't have multiply or divide).
My interpretation of the code is that it leads to an effective shape like the one in this graph, where the overall size is determined by the sum of the size of the two involved objects:
https://github.com/nmikstas/asteroids-disassembly/blob/maste...
(the commentary of the same lines at https://computerarcheology.com/Arcade/Asteroids/Code.html is incomplete by comparison)
My interpretation of the code is that it leads to an effective shape like the one in this graph, where the overall size is determined by the sum of the size of the two involved objects:
https://www.desmos.com/calculator/k63qoshhqx