This patch adds the possibility to alter the angle of
the tank's barrel. Now you will be able to shoot the
chickens hiding on top of a building (with jump flag)
in a no jump world.
For now the keys for controlling the angle of the
barrel are hardcoded: Q = up, A = down.
This patch will only work when your opponent also has
the patch applied. This because of some bad design in
the game :( The bullet velocity is squashed to zero in
1) when you fire the shot locally
2) when an opponent receives your shot
Especially that last one is quite enoying.
Another thing, I also draw an 'X' on the HUD so you can
see the angle of the barrel. I'm not quite sure that
this will render ok on other resolutions than mine. It
looks ok for me, but I'm not familiar with the fine
details of OpenGL, so there might be a better way of
doing it so it looks ok for everyone.