Trajectory problems

[Randolf Nitler]

You probably heard this before, but i have a problem with getting my tanks to shoot at each other at an angle so that the missile curves while traveling towards the other player. So far I have 4 variables: power, angle, playerpositionX, and playerpositionY. Can som1 help me with making a formula that i can use to get my tanks to shoot properly. I'd also very much appreciate it if you could also code it for me so that i can change it into my variables and have it working. Just a simple demo is all I need. Thanks again.

[Tony]

Randolf Nitler @ Thu Jan 10, 2008 12:10 pm wrote:

I'd also very much appreciate it if you could also code it for me

This is against forum rules.

To get the trajectories, you will need to keep track of vertical + horizontal velocities and acceleration. Just like in a typical "throw object from a cliff" type of problems from the Physics class.

[LaZ3R]

lmao, those kind of questions were fun .

Nitler, this isn't a forum where you get answers. Learn how to do things yourself or ask for help instead. No one here will/is allowed to simply post code for you so you can take it and manipulate it for your own usage instead...

If you give a man a fish, he has food for a day. If you teach him how to fish, he has food for life.

Same idea...

[Randolf Nitler]

I feel so stupid now =/ Alright sorry about that, I've fixed my problem now

[CodeMonkey2000]

It's really not that hard. Once you get the missile to go at the desired angle, then y component of the speed of the missile needs to decrease at a constant rate.

[Randolf Nitler]

Currently this is what i have, and I have 2 little problems with what i have here:
1. If i set angle to 2, or 3 and so on, the missile isnt drawn
2. if i set angle to 45, notice the missile doesn't start at the exact angle of 45
please help, and show where my mistakes are so i can fix them!

code:

% setscreen size setscreen ("graphics:1000;500,offscreenonly") % get the player variables var player1locationX, player1locationY, radius : int player1locationX := 15 player1locationY := 15 radius := 15 % draw the player onto the screen drawfilloval (player1locationX, player1locationY, radius, radius, brightred) drawfilloval (player1locationX, player1locationY, 3, 3, black) loop     % for the missile must go up, and then come down at a certain time     % put time in a for loop     for t : 1 .. 100         delay (200)         % name missile variables         var currentXlocation, currentYlocation, power, angle, gravity : real         gravity := -1         angle := 2         power := 20         currentXlocation := cos (angle) * power * t         currentYlocation := sin (angle) * power * t + 0.5 * gravity * (t) ** 2         % draw the missile         drawfilloval (round (currentXlocation), round (currentYlocation), 3, 3, black)         if currentYlocation < 0 then             quit         end if         View.Update     end for end loop

[Tony]

are you sure that cos/sin operate on degrees, not radians?

[Carey]

try cosd and sind instead. they use degrees, not radians