hi, i have this code for jumping but it needs to be fixed..

var alt = 20;




player script
var floor;
VECTOR temp;
vec_set(temp.x, my.x);
temp.z -= 10000;
floor = c_trace(my.x, temp.x, IGNORE_ME | IGNORE_PASSABLE | USE_BOX | GLIDE);

{
if(floor < alt)
{
if(key_space)
{
c_move(me,vector(0, 0, 10*time_step),nullvector, GLIDE);
if(floor > alt)
{

c_move(me,vector(0,0,-1*time_step),nullvector, GLIDE);
}
}
}

its for jumping, and the idea its that when the player has reached the max altitud ( var alt = 20) the key has to get disable until the player touches the ground again, the problem its that the "if(floor < alt)" allows the player to jump not only when the player is in the air, but any moment as is in the air aswell.. so i dont know how to do to recognize when the player is on the floor to get the key to be able to jump again.

Expand the statement if(floor < alt) with examination of floor, like this if(floor < alt && floor > 0 && floor < 3).
you can tune the constant value 3 to guess out which value is fit for you.

what code would tell me exactly when the player is on the floor? coz the "floor < alt" means the that player's position is less than alt but still is in the air...

It depends on what shape has the floor and what is the coordinates of the top surface of that.

the level its just a hollow cube and blocks. its a simple 3dr person plataform game =)

I think the floor is the lower side of the cube.
The floor position is:
1. z value of the cube's origin place vector (height from world 0,0,0 point)
plus
2. the distance of the cube's origin from the lower side.

This sum gives surface's ground zero in world coordinates.
IMHO
(Naturaly substitute the plus operation with minus :))

still unsolved!! i almost got it but the problems is that i can jump on the air, so what i what is that the key space turns unable while the player is in the air, and get able only when it touches the floor to be able to jump again..

if(key_space && alt==0)