Forums » Help » Strange bug with collisions

I'm working on a breakout clone to get to know impactjs. So far so good.
But I noticed that sometimes the ball after bouncing to the walls will go down in a 90 degrees, and that wasn't right.

Here is my collision map:

gist to ball entity

and here is a video of what's going on video

Where do I start debugging?

Wanted to make a note that it's not happening all the time, if I move the paddle and the ball gets another angle it doesn't happen.

A couple of things:

You can make use of the JS statement debugger. Put it inside of an if, say...

updateAngle: function() {
  this.angle = Math.atan2(this.vel.y, this.vel.x).toDeg();
  if (this.vel.x === 0) {
    debugger;
  }
  this.speed = Math.sqrt(Math.pow(this.vel.x, 2) + Math.pow(this.vel.y, 2));
},

You can also set conditional breakpoints in the Chrome DevTools to see what happens when your angle is 270.

You probably want your override of handleMovementTrace to call its parent first, before your code. Otherwise, you are setting velocity by angle/speed, then Impact comes along and resets it based on the collision map.

In the base handleMovementTrace, if your vel.x isn't greater than the minBounceVelocity (defaults to 40), then your vel.x will get set to 0.

I wouldn't bet hundreds of dollars that that's what's going on... but I have my suspicions.

@drhayes:

Thanks for your tips. The problem was minBounceVelocity, cause vel.x was dropping below 40 and then the bounce stopped.

About the handleMovementTrace and calling parent first.
The idea was that parent update the velocities and then I can update the ball speed and update the velocities again... if I do parent first that gets screwed up and the ball doesn't bounce.

Thanks again.

PS: didn't know about the debugger code line... I was using dev tools breakpoints.

Note to self: next time, bet hundreds of dollars.