RE: Stupid Asteroids Tricks...

> > D7 D6 D5 D4 D3 D2 D1 D0
> > a x x x x i j k
> >
> > a = UFO exploding when set
> > x = seems to cause the UFO to appear, haven't really figured it out
> > i = when set, makes the HUGE UFO
> > j = when set, makes the Large UFO
> > k = when set, makes the Small UFO
>
> Which begs the question -- what happens if more than one of i, j, and
> k are
> set ?
>
I think I tried that and it took the largest size... I haven't looked
at the code that actually *acts* upon the value of $21C, but if it's
like the asteroid code it's setting up the display list based on the
value of this "display attribute" byte.

The asteroids work about the same-- the asteroid directions and
velocities are set up and then whether or not the asteroid shows up is
just based on that "display attribute" byte. It says the shape of the
asteroid, the size of the rock, and whether or not it's exploding.
(Which makes for the interesting "mines" effect I talked about-- if you
turn an asteroid on, but the direction vectors are not initialized it'll
be "active", but just sitting there on the screen... The main gotcha
there is if you turn on an asteroid that's too close to the center of
the screen, the player ship will never appear because the asteroid is
violating the "fairness" check that's looking for rocks right by the
ship before "reappearing" the player.

-Clay

-Clay
Received on Thu Feb 25 12:29:48 1999