function turn_towards_target()
{
  // get the direction from the entity MY to the entity YOU
  vec_set(temp,your.x); 
  vec_sub(temp,my.x);
  vec_to_angle(my.pan,temp); // now MY looks at YOU
}

VECTOR temp;
  vec_set(temp,your.x); 
  vec_sub(temp,my.x);
  my.pan += clamp(ang(temp-my.pan)*0.5,-25,25)*time_step;

//////////////////////////////////////////////////////////////////
// turn towards an absolute target angle with given angular speed
// use wait_for_my(ent_turnto) for determining when the angle is reached
function ent_turnto(ENTITY* ent,ANGLE* to,var aspeed)
{
	proc_kill2(ent_turnto,ent);
// store the "to" angle for the wait loop - it could be a temporary vector!	
	ANGLE atarget;
	vec_set(atarget,to);
	 
	while(aspeed) {
// calculate the difference between the current and the target angle	
		ANGLE adiff;
		ang_diff(adiff,atarget,ent.pan);
// check if we're already there
		if(vec_length(adiff) <= aspeed*time_step) {
			vec_set(ent.pan,atarget);
			return;
		}
// scale the difference angle by the angular speed, 
// and add it to the entity angle
		vec_normalize(adiff,aspeed*time_step);
		ang_add(ent.pan,adiff);
		wait(1);
	}
}

// turn towards a target position with given speed
// use wait_for_my(ent_turnto) for determining when the angle is reached
function ent_faceto(ENTITY* ent,VECTOR* pos,var aspeed)
{
	if(!ent || !pos) return;
	VECTOR* diff = vec_diff(NULL,pos,ent.x);
	vec_to_angle(diff,diff);
	ent_turnto(ent,diff,aspeed);
}