A short question - how do get a pixel to travel in a x^2 curve?

You get the velocity by deriving the formula:

Position
F(x) = x2

Speed
dF(x) = 2x

Acceleration
ddF(x) = 2

But if you want to do a ballistic course of a shell you might consider something like this:

Fire location
Pos = (x,y)

Fire speed
Spd = (dx, dy)

Then you move the shell iteratively by this algorithm

1. Update location
   Pos = Pos + t*Spd;
   
2. If collision then exit loop
   
3. Update speed
   Spd.dy += t*GravityConst;
   Spd.dx += t*Wind;
   
4. Goto 1
   

Edited by - Spellbound on 2/28/00 10:26:14 AM

I have corrected the error that webspynner_99 mentions below.

Edited by - Spellbound on 3/1/00 6:41:22 AM

That works great! Thanks!!

Actually if F(x)=x^2, then F''(x)=2x and F''''(x)=2 not 0 as spellbound had said.

Oops...