A better way to do vertical collision?

[lamatoast]

Is there a better way to do vertical collisions? because when use this way, it sometime draws the player one pixel into the ground and it's driving me crazy.

vsp += grv

if place_meeting(x,y+vsp,obj_wall)
{
    while !place_meeting(x,y+sign(vsp),obj_wall)
    {
        y += sign(vsp)
    }
    vsp = 0
}

y += vsp

 

[Nidoking]

if place_meeting(x,y+vsp,obj_wll) { while !place_meeting(x,y+sign(vsp),obj_wall)

Are obj_wll and obj_wall two different things?

 

[Slyddar]

Are you using different sprites for in the air and on the ground, and if so are their origins and masks aligned? Try using the same mask for both by changing the object mask to the ground sprite.

 

[lamatoast]

@Nidoking sorry typo

 

[lamatoast]

@Slyddar all that is good, it's been a problem for a while and is more noticeable in low res games

 

[TailBit]

You could store the fraction value in a separate variable before doing the collission check vfrac = frac(vspd);, then remove it from vspd so vspd is a whole number before the calculation vspd = abs(vspd)*sign(vspd), you add the old fraction value the same place you add gravity vsp += grv + vfrac;

 

[The Astronaut]

Try replacing "y += sign(vsp)" with "y = floor(y) + 1" if you're going down and "y = ceil(y) - 1" if you're going up and you might not have to do anything else

 

[Slyddar]

Try replacing "y += sign(vsp)" with "y = floor(y) + 1" if you're going down and "y = ceil(y) - 1" if you're going up and you might not have to do anything else

Just wondering if you have tested that change before?

In answer to the OP, if you run tile collisions, once a collision occurs, movement to the tile is in integers, so you end up with perfect collisions.

 

[lamatoast]

Thanks guys got it working