bump, anyone?

if you've doubled the walking speed, wont just doubelling the other speeds work?

i tried that and it does not work. the height and length of the jump vary still

Can you clarify your question? I thought y-movement is generally independent from x-movement, and since you said walking speed is constant, x = x0 + v0t + .5at2 wouldn't really make much sense.

ok, so i have the variables x, y, and yVel. there's also the constants XVEL, GRAVITY, and JUMP_FORCE. XVEL is how many pixels the character moves right each frame. GRAVITY is how many pixels the character falls each frame (if it can fall). JUMP_FORCE is the initial upward velocity when the user presses space (makes the character jump). i tweaked my engine so that the character jumps at a desire length/height. but now i want to double XVEL, making the character move twice as fast. however, now i need to tweak GRAVITY so that the character falls faster, in order to make sure the length of the jump remains constant. but because i tweaked GRAVITY, now JUMP_FORCE needs to be modified so the height of the jump remains constant as well. however, i don't know how much to modify these constants. and it isn't as simple as doubling GRAVITY and JUMP_FORCE, i already tested that.


edit: alright, i think i've found an equation. if XVEL is multiplied by p, JUMP_FORCE is multiplied by p and GRAVITY is multiplied by p^2.

right now i'm trying to tweak my engine so i can get some data (e.g. what's GRAVITY and JUMP_FORCE when XVEL is multiplied by 2? multiplied by 3? etc...) and then use a regression to find an equation from that. but i was wondering if anyone knew how to figure out the equation mathematically.