I'm looking for some explanation about vec_length cause the manual is not than clear.

I try to make ma character react in a different way if the other character is benind him in the X axis but when I try with vec_length it doesn't work, the character didn't detec the instruction.

vec_length (play1.x);
vec_length(play2.x);


if (play1.x<play2.x)

{ ...

did i misunderstand the function of vec_length ? do you have some example ?
Do I've to try with c_trace?

Thanks for your help

The manual has an example:

distance = vec_length(my.x); // calculate the distance of the my entity to the level origin

So you need to save the magnitude of those vectores in a variable for example.
Also, if you want to have always a positive value to evaluate, take a look at abs() command which returns an absolute value.

So when you said the distance is not for example
my entity = -30

it's the distance between the origin and the entity is 30 ?

so with vec_length I can't compare two position on the X axis ? like
if my.entity.x < your.entity.x

I tried with abs but it didn't work.

cheers

If you only want to compare positions on the X axis for some reason, then it's just (my.x < your.x). You don't need vectors for that.

I did use to compare 2 x position with

play1 and play2

My.x and your.x was an example, the engine says there is an empy pointer even if I define play2= you

is it cause they are two entity controlled by different players ?

It shouldn't be a problem to have two entities controlled by different players.

Here is an example code that should work (e.g. for a splitscreen game):
Code:

---

entity* player1;
entity* player2;

action player1_act
{
  player1 = my;
  //here comes the rest of your movement code for player 1
}

action player2_act
{
  player2 = my;
  //here comes the rest of your movement code for player2
}

---

Now you should be able to get the x-distance between both of them and store it into a var:
Code:

---

var distance;

//put this into a function:
distance = abs(player1.x - player2.x);

---

But you have to make sure that both entities exists and that their pointers are not zero.

Big confusion around here.

Like jcl said, if you only want to compare two positions along the x axis it very simple:



You need to have the pointers defined for the two entities, so:

if(entity1.x < entity2.x) //entity1 behind entity2
{
...
}

I cant see where is the problem here.

You can do that with vectors too but this way its simpler.

Edit: Thunder was faster

you're both right but in fact it doesn't work and I don't know why

My code is a bit complicated so to avoid error I've made one simplier to see is the program could make a simple action like if (entity.1<entity.2)
{Z+=5;}

but It didn't work when I change entity's position

maybe I need to update them, it's the reason i've decided to use vec but I didn't find the way to get the update


this is the simple code


action play1

{
while(1)
{
p1= me;
my.x+=2*key_force.x*time;
if (p1.x>p2.x)
{
my.z+=5*time;
}
wait(1);

}
}

action play2{

while(1)
{
p2=me;
my.x+=2*joy_force.x*time;wait(1);
}


}

1. Do not assign the pointers in the while loop, just put it in begin of the action:

Code:

---

entity* p1;
entity* p2;

action play1
{
   p1 = my;
   while(p2==null){wait(1);}
   while(1)
   {
      my.x += 2 * key_force.x * time;
      if (my.x > p2.x)
      {
         my.z += 5 * time;
      }
   wait(1);
   }
}

action play2
{
   p2 = my;
   while(1)
   {
      my.x += 2 * joy_force.x * time;
      wait(1); 
    }
} 

---

This should work. Dont forget you need to move p1 to a point where its x is superior do p2, otherwise it wont work.