Gravity and jumping

[hamid14]

What is it you are trying to achieve?
Trying to make a picture "jump" up, then come down. Basically, im trying to make gravity.


What is the problem you are having?
Cant get the gravity to work right.


Describe what you have tried to solve this problem
I've tried making the y decrease after it reaches the max height for the jump, doesnt work.


Post any relevant code (You may choose to attach the file instead of posting the code if it is too long)
Heres the code

Turing:

View.Set ("offscreenonly") var x,y : int := 100 var chars : array char of boolean loop View.Update cls Input.KeyDown (chars) if chars (KEY_UP_ARROW) then y :=y + 5 end if if y >= 200 then y := y - 5 end if if y >= 100 and y <=105 then y := 100 end if end loop

Please specify what version of Turing you are using
4.1

[TheGuardian001]

Turing:

var y : int := 100 loop     Input.KeyDown (chars)     if chars (KEY_UP_ARROW) then         y :=y + 5     end if     %STUFF     if y >= 100 and y <=105 then         y := 100     end if     %DRAW CHARACTER end loop

based on those two conditions, will the value of y ever be anything other than 100 when the character is drawn?

[highly]

Turing:

View.Set ("offscreenonly") var x,y : int := 100 var chars : array char of boolean loop View.Update cls Input.KeyDown (chars) if chars (KEY_UP_ARROW) then y :=y + 5 end if if y >= 200 then y := y - 5 end if if y >= 100 and y <=105 then y := 100 end if end loop

gravity is a force, and is a constant. In this case, g(gravity) will always be a negative value acting on your character. But it wouldn't effect the y position of your character directly, it would effect that characters velocity. so y += yvel, and yvel is what is effected by keypresses

Turing:

%declaring variables var x, y : int var vx, vy : int var g : int var f : int var j : boolean x := 100 y := 200 vx := 0 % x velocity vy := 0 % y velocity g := 1 % g is gravity j := true % boolean for whether or not "jump" is allowed var chars : array char of boolean loop     Input.KeyDown (chars)     if chars (KEY_UP_ARROW) and (j = true) then         vy := 10 % accelerates upward to a jump         j := false % so that it doesn't fly into space     end if     if y <= 200 then % 200 is where out "ground" is         j := true         vy := (vy * -1) - 1 % Bounce effect. Should be (vy*-1)*0.5, but that equation didn't work         y := 200 % this means if our characetr is below "ground", then he gets put back on top of the ground     end if     if y > 200 then % this if makes it so you cannot jump in mid-air         j := false     end if     if chars (KEY_RIGHT_ARROW) then % increases the x velocity         vx += 5     else         if chars (KEY_LEFT_ARROW) then %decreases the x velocity             vx -= 5         else             if chars (KEY_DOWN_ARROW) then % makes it so you can "stop" the character if going to fast, again I couldn't do friction becaue the equation didn't comply                 vx := 0             end if         end if     end if     if j = false then % this is our gravity effect. If he can't jump, it means he is above the ground. If he is above the ground, gravity would apply to him         vy -= g     end if     x += vx % stating to move x velocity space son the x axis     y += vy % same except for y     drawoval (x, y, 4, 4, black) % drawing oval     delay (50) % delay. if 0 everything goes whack.     cls end loop

again, these are just some of the basics for applying physics in coding. It's very sloppy and incomplete because I'm not completely familiar with Turing's math operations.

[Kharybdis]

darn it, i have a complete simulation somewhere on my computer that has a very good explanation of how everything works and has an example of it... just need to find it. Sorry, writing this very late at night .

MetaChief wrote it, you should ask him for it. I know it helped me a lot when doing elementary physics coding.