box2d contact listener fixtures order

Question

I am trying to understand how does it work.

In my game I use box2d physics, to handle contacts I use contact listener, example:

ContactListener conta         


        

Answer 1

No, there is no guarantee which fixture is which. You have to check for both possibilities, like this:

if ( (userdataA.equals("player") && userDataB.equals("ground")) ||
     (userdataA.equals("ground") && userDataB.equals("player")) )
         player.increaseFootContacts();