Simple Enemy AI


I am creating a mega man-like game. I need some simple enemy movement code that needs to:

  1. Activate the enemy’s movement only when the player is within a certain proximity of the enemy.
  2. “Fly” (both enemies are bugs) towards the players’ registration point until it is killed.

That’s it. It seems pretty simple, but I am having trouble with it. Especially when the enemy reaches the registration point. It starts to go crazy. Here is an example of my code which uses simple pythagorean calculations:

function enemyMovement(enemy:String):Void {
    //movement calcs
    var run:Number = outScreen[enemy]._x - outScreen.megaman._x;
    var rise:Number = outScreen[enemy]._y - outScreen.megaman._y + 34; 
       //34 above accounts for registration point offset
    var distance:Number = Math.sqrt(Math.pow(rise,2) / Math.pow(run,2));
    var angle:Number = Math.pow(Math.tan(rise / run), -1);
    //actual movement
    outScreen[enemy]._x += Math.sin(angle);
    outScreen[enemy]._y += Math.cos(angle);
    //collision detection
    var bOverlap:Boolean = outScreen[enemy].hitTest(outScreen.megaman);
    //decrease health
    if (bOverlap) {

Anyone posting can focus more on the movement as I will most likely be able to add the proximity aspect without trouble… ::fingers crossed::