Programming an Arch

Post by **Jeff-20** » Wed Sep 16, 2009 9:35 pm

I want to create a program to simulate an arch a la Artillery Duel. This could useful for jumping or side-view projectile motions. I know this is probably a simple math question, but I am open to suggestions. I want to figure out a way to do it with speed.

matsondawson · Post by **matsondawson** » Wed Sep 16, 2009 10:43 pm

I'd guess something like this.
Doesn't need a whole lot of CPU.

Code: Select all

10 g=0.05
20 vx=3;vy=3;x=0;y=0
30 ? "bang"
40 x=x+vx;y=y+vy;vy=vy-g;
50 [plot bullet at x,y]
60 if y>0 then goto 40
70 ? "boom"

IsaacKuo · Post by **IsaacKuo** » Thu Sep 17, 2009 5:28 am

Probably "vy=vy+g" rather than "vy=vy-g". I'm assuming +y is "down" rather than "up".

Oh, and to "jump", you need to start with a negative vy, like "vy=-3".

BTW, the mathematical term for this curve is a "parabola".

matsondawson · Post by **matsondawson** » Thu Sep 17, 2009 3:27 pm

IsaacKuo wrote:Probably "vy=vy+g" rather than "vy=vy-g". I'm assuming +y is "down" rather than "up".

Oh, and to "jump", you need to start with a negative vy, like "vy=-3".

BTW, the mathematical term for this curve is a "parabola".

Nope +y is up, if you added g then it would shoot off into space.
Depends on your coordinate system.

IsaacKuo · Post by **IsaacKuo** » Thu Sep 17, 2009 3:36 pm

My point is that for his purposes, +y is probably going to be down (with 0 at the top of the screen).