Balls are stuck in mirror positions at intersection point

[seve]

Left it on for about 30 minutes and it looks like the balls got stuck inside of each other's collision boxes.

Screen.Recording.2024-01-29.at.11.47.10.AM.mov

[erkantaylan]

since there is no random in the code. i got the exact same :D

[MattTheCuber]

same

[shmalex]

got absolutely the same situation

[thrust26]

I got similar results in my Atari 2600 version.

But after I improved the block collision detection, the problem disappeared. I only check collision with blocks into the ball's current direction. E.g if the ball moves left and up, I only check the blocks to the left and above.

[pathikrit]

Same, I got this too after an hour or so:

The code is fully deterministic. I would introduce a tiny random epsilon on each bounce angle

[masterfelu]

maybe random initial start position?

[non-descriptive]

They gonna lock each other somewhere else. Mine stuck somewhere in the middle in even tighter position.

[serkonda7]

This position as well

[pathikrit]

Ok idea to prevent loop (or a cycle of length = 1) - if same 2 positions are repeated as pairs across 4 ticks that means we are in a loop. For 5th tick, we skip and go to 6th tick. This will give a chance for a ball to move twice and clear the loop. Concretely:

tick1: position1, ball1
tick2: position2, ball2
tick3: position3, ball1
tick4: position4, ball2

if position1 == position3 and position2 == position4 then:
  // do nothing for tick5

tick6: position6, ball1

Now this prevents cycles of length=1. Its not clear if there could be longer cycles. If indeed, there are cycles of length>1, we can generalize to store last 2*length positions and see if we see the same pair of consecutive position twice

[Abyss-Seeker]