//asteroids.fla
//By Andy Harris, Dummies Guide to Game Programming in Flash
init();
function init(){
//normal initialization
myShip.dx = 0;
myShip.dy = 0;
myShip.speed = 0;
myShip.dir = 0;
myShip.gotoAndStop("still");
buildRocks();
} // end init
function buildRocks(){
//rocks rely on rock.as class definition
for(i = 0; i < 5; i++){
_root.attachMovie("rock", "rock_" + i, 10 + i);
} // end for loop
} // end buildRocks
myShip.onEnterFrame = function(){
myShip.checkKeys();
myShip.turn();
myShip.move();
} // end if
myShip.checkKeys = function(){
//check for left and right arrows
if (Key.isDown(Key.LEFT)){
this.dir -= 10;
this.gotoAndStop("left");
if (this.dir < 0){
this.dir = 350;
} // end if
} else if (Key.isDown(Key.RIGHT)){
this.dir += 10;
this.gotoAndStop("right");
if (this.dir > 360){
this.dir = 10;
} // end if
} else if (Key.isDown(Key.UP)){
//thrust on up arrow
this.thrustSpeed = 1;
this.gotoAndStop("thrust");
} else {
this.thrustSpeed = 0;
this.gotoAndStop("still");
} // end if
} // end checkKeys
myShip.turn = function(){
this._rotation = this.dir;
//trace("I'm here...");
//get new thrust vector
degrees = this.dir
degrees -= 90;
radians = degrees * Math.PI / 180;
thrustDX = this.thrustSpeed * Math.cos(radians);
thrustDY = this.thrustSpeed * Math.sin(radians);
//add thrust to dx and dy
this.dx += thrustDX;
this.dy += thrustDY;
} // end turn
myShip.move = function(){
this._x += this.dx;
this._y += this.dy;
//wrap around screen
if (this._x > Stage.width){
this._x = 0;
} // end if
if (this._x < 0){
this._x = Stage.width;
} // end if
if (this._y > Stage.height){
this._y = 0;
} // end if
if (this._y < 0){
this._y = Stage.height;
} // end if
} // end move