I am playing HL2 for the first time. I am playing on a MBP and have come across a control problem with the trackpad. I have reached Black Mesa East and the tutorial for using the anti gravity gun. Because I'm using the trackpad, I am finding it impossible to control this weapon. For those who have played HL2 on a MBP, how did you configure the trackpad for the game, and/or how did you work around to control this weapon with the trackpad?