How do I calculate efficiently the required angle to rotate from one entity to another?
My code is as follows


Code:

---

 
function is_ReturnAngleForTurningToEntity(eAgent,eTarget)
{
	my=eAgent;
	you=eTarget;
	
	// get the direction from the entity MY to the entity YOU
	vec_set(temp,you.x); 
	vec_sub(temp,my.x);
	vec_to_angle(is_tempvec5,temp);

	return(is_tempvec5.pan);
}

FUNCTION rotate_entity(rotate_angle,rotate_speed)
{
	IF (my.pan == rotate_angle) { return; }
	
	result = ang(rotate_angle - my.pan);
	IF (result > 0) { my.pan += rotate_speed * time; }
	IF (result < 0) { my.pan -= rotate_speed * time; }
	IF (ang(rotate_angle - my.pan) < 0 && result > 0) { my.pan = rotate_angle; }
	IF (ang(rotate_angle - my.pan) > 0 && result < 0) { my.pan = rotate_angle; }
}

action player
{
		while(my.pan!=is_tempvec5.pan)
		{
			rotate_entity(is_tempvec5.pan,30*time);
			temp = abs(my.pan - is_tempvec5.pan);
			if(temp<5){break;}
			wait(1);			
		} 
}
 

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Can you please elaborate what your trying to do with rotate, are you trying to get one entity to face another, two entities to rotate until the are face to face? or what, could be anything from what you describe.

Sorry for the lack of info.
I'm trying to make one entity rotate to face another one.
function is_ReturnAngleForTurningToEntity should calculate the pan difference required to face the target.
FUNCTION rotate_entity does the trick, but needs to be constantly updated.
So the action uses a while loop to keep the entity turning till it faces it's target.

Alright, sorry I don't have more time but I have to get to work again, but with my first look over it seems that your nothing calls the function is_ReturnAngleForTurningToEntity(eAgent,eTarget) this means that is_tempvec5.pan is never existing in your action, you must call it in action so something like
-----------------------------------------
//Note you must define first_entity and second_entity to be the appropriate entities
is_tempvec5.pan = is_ReturnAngleForTurningToEntity(first_entity, second_entity);
//this must be right before

while(my.pan!=is_tempvec5.pan)

//to work
---------------------------------------
This is just a rough guess, but I've let you know what is definately wrong, I'm going to be busy for at least another day, so hopefully this will help you enough to get you going again.

This is what You need:
Code:

---

 

function player_move()
{
	while(1)
	{
 	vec_diff(temp,my_target,my.pos); //my_target maybe You ent pos
	result = vec_to_angle(my_angle,temp);
	my._speed = 10;
	actor_turnto(my_angle.PAN)
	wait(1);	
	}
}

function actor_turnto(angle)
{
	angle = ang(angle - MY.PAN);
	if (angle > 10) {temp = my._speed;}
	else{
		if(angle < -10){temp = -my._speed;}
		else{temp = my._speed * angle * 0.1;}
		}
	MY.PAN += temp * time_step *2;//change this to faster turning
}
 

---

I've checked it and its 100% working