[Solved]Why Collision Detection Not Working [Code Error]

Question

https://code.sololearn.com/W0kM4J5r9WcF/?ref=app
i am trying to do fun with collision detection but here in this code sometimes two box colloide and didn't get separate ,
Like This
https://www.sololearn.com/post/1200072/?ref=app
How can i separate them?

Answer 1

[part 1]

The boxes are sticking together because of the way you handle velocities after collision

if you just flip the velocities evertime (multiplying by -1)
for the boxes which are overlapped by some pixels less than the mag of velocity will beahave normally

but for the boxes which overlapped by px more than the magnitude of velocity in both axis this will happen

in one frame it will detect collision and flip velocity
then Box will move in opposite direction (= mag(velocity)px ) and as the overlap is greater than the mag of velocity boxes are still colliding and hence in next frame it will detect collision again and reverse the velocity again in the wrong side so it becomes same as before.. and this will continue forever
that's the reason for that vibration and box sticking together

another bug: collision isn't realistic as it flips both axis at the same time. I can explain more if you want

Answer 2

Virtual Pixel
Thanks ,
Now i got it

Answer 3

[part 2]

potential fixes :

push the boxes apart after detecting collision into opposite direction equal to the amount of overlap so they are apart

Answer 4

One of the solution would be, to use a flag to indicate whether the same collision session has been exited.

a demo for another sololearner a few years ago:

https://code.sololearn.com/W385n4ccicXX/?ref=app