Angle Functions

//NormalizeAngle(angle).

//Converts the passed in angle into an angle between 0 and 360, not including 360.
//Examples: NormalizeAngle(540) = 180, NormalizeAngle(-270) = 90, NormalizeAngle(360) = 0.


function NormalizeAngle(angle){
  angle %= 360;
  if(angle<0){ angle += 360; }
  return angle;
}

//AngularDistance(angle1, angle2).

//Gets the smallest angle between angle1 and angle2. Will always return a number between -180 and 180, not including //-180. A positive number means the shortest way from angle1 to angle2 goes clockwise, a negative number means the //shortest way goes counterclockwise. Also uses the NormalizeAngle function from above.
//Examples: AngularDistance(90, 180) = 90, AngularDistance(180, 90) = -90, AngularDistance(1, 359) = -2.


function AngularDistance(angle1, angle2){
  let distance = NormalizeAngle(angle2 - angle1);
  if(distance>180){ distance-=360; }
  return distance;
}

//Function for objects: TurnToAngle.

//Three Parameters, which are id, speed and angle.

//Makes an object bullet/laser turn till it's angle is equal to the number input as the parameter angle. Doesn't loop //by itself. Speed is the speed it turns at. Inputting a negative value for speed gives you awkward results. Id is //(obviously) the id of the object.


function TurnToAngle(id, speed, angle){
    let current_angle = Obj_GetAngle(id);
    let target_angle = angle;
    let adist = AngularDistance(current_angle, target_angle);

    if(absolute(adist) < speed){
        Obj_SetAngle(id, target_angle);
    }
    else {
        if(adist > 0){
            Obj_SetAngle(id, Obj_GetAngle(id)+speed);
        }
        else if(adist < 0){
            Obj_SetAngle(id, Obj_GetAngle(id)-speed);
        }
    }
}