OK
i made it work ( not really) Im still implementing some features to make it more reallistic but the OVERALL IDEA works but with ONE BLOODY PROBLEM.
here is the code
Code:

---

function put_grass()
{
	
	if(grass_index < 200)
	{

	teste2 =grass_index; //just for debugging purposes
	you = grass_pointer[grass_index];

	you.x = nearest_pos_x;
	you.y = nearest_pos_y;

	grass_index += 1;	
	
	}

	return;
	
}


function define_nearest_pos()
{
grass_index = 0;	//reset
grass_array_index = 0; //reset

	
	while(grass_array_index < 1000)
	{
		if(vec_dist(global_player_pos.x,grass_array_x[grass_array_index] ) < 8000)&&(vec_dist (global_player_pos.y, grass_array_y[grass_array_index]) < 8000)
		{
			
		nearest_pos_x = grass_array_x[grass_array_index];
		nearest_pos_y = grass_array_y[grass_array_index];
		put_grass();
		}
		
	grass_array_index += 1;
	}
	
}

function initial_grass_func()
{
	my.passable = on; 
	my.scale_x = 0.5;
	my.scale_y = 0.5;
	my.scale_z = 0.5;
	my.z = 64;

}


function define_grass_and_positions()
{
	i_max_grass = 0;//reset
	i_grass_array_index = 0; //reset

	
	while(i_grass_array_index < 1000) 
	{
		grass_array_x[i_grass_array_index] = random(10000);
		grass_array_y[i_grass_array_index] = random(10000);		
		i_grass_array_index += 1;
	}
	
	while(i_max_grass < 200)
	{
		grass_pointer[i_max_grass] = ent_create (grass1, nullvector, initial_grass_func);		
		i_max_grass += 1;
	}
	
		if(i_grass_array_index >= 1000)&&(i_max_grass >= 200){define_nearest_pos();}//IF its has finished defining and creating ...
	
}

---

At first the "define_grass_and_positions()" function is called first, then down the road the function "define_nearest_pos()" is called by another function(not listed here) eveytime the variable "grass_array_index" gets to a 1000 so its always updating.


The problem is
Everytime I start the Engine sometimes its just doesnt work, the variable "grass_index" stays at 0 (zero) and sometimes it works fine.


anyone has any idea why?