Extra tracks: HookMoveBack

       Name: HookMoveBack                                            [Show more]
       Type: Subroutine
   Category: Extra tracks
    Summary: Only move the player backwards if the player has not yet driven
             past the segment
  Deep dive: Secrets of the extra tracks
             Code hooks in the extra tracks
    Context: See this subroutine in context in the source code
 References: This subroutine is called as follows:
             * newContentHi calls HookMoveBack
             * newContentLo calls HookMoveBack


 This routine is called from MovePlayerSegment to change the behaviour when
 moving the player backwards along the track.

 Only move the player backwards by one segment if bit 7 of playerPastSegment is
 clear (in other words, if the player has not yet driven past the segment).


.HookMoveBack

 BIT playerPastSegment  \ If bit 7 of playerPastSegment is set, return from the
 BMI HookMoveBack-1     \ subroutine (as HookMoveBack-1 contains an RTS)

 JMP MovePlayerBack     \ Move the player backwards by one segment, returning
                        \ from the subroutine using a tail call