Bug in the sprite/mech code

[Eero Tamminen]

Hi,

There's a bug in the sprite or mech code which is easy to replicate.
I've added a few DEBUG printfs to code in CVS to demonstrate this
(once the bug is fixed, I'll remove them).

Case one:
- How to replicate:
  - In level 2 settings, use "vx = -0.4" for Hippo
  - "airstrike -level 2", wait a few secs
- The problem:
  In mech.c, hippo sprite goes through check for (base.x < 0)
  although it's in the middle of the screen.  (as a result Hippo
  code gets outofbounds message and kills itself)

Case two:
- How to replicate:
  - In level 2 settings, use "vx = 1" for Hippo
  - "airstrike -level 2", wait a few secs
- The problem:
  Hippo starts to rotate, but once it's done one round, rotating
  stops when it's again in horizontal position.  After that Hippo
  sinks half to the background and then other object can pass
  through it (the half that's above ground).  Bullets can still hit
  it though.

Ulf, could you test this and see why this might happen?
It might be something related to rotation as besides biplane,
hippo is only sprite that rotates.

	- Eero