Flash Game Tuts - Free Flash Game Tutorials in AS2 and AS3

How to Create a Tower Defense Game in AS3 – Part 2

Part 2: Adding Turrets

Okay, so in this part of the tutorial, we are going to make it so when the user clicks on any of the empty blocks, a turret is created. The first step to take in to create a Turret class. You know the drill, create a new ActionScript File, save it as “Turret.as”, and type in the following code:

package{//creating the basic skeleton
	imporProxy-Connection: keep-alive
Cache-Control: max-age=0

flash.display.MovieClip;
	import flash.events.*;
	public class Turret extends MovieClip{
		private var _root:MovieClip;

		public function Turret(){
			//adding the required listeners
			this.addEventListener(Event.ADDED, beginClass);
			this.addEventListener(Event.ENTER_FRAME, eFrameEvents);
		}
		private function beginClass(e:Event):void{
			_root = MovieClip(root);

			//drawing the turret, it will have a gray, circular, base with a white gun
			this.graphics.beginFill(0x999999);
			this.graphics.drawCircle(0,0,12.5);
			this.graphics.endFill();
			this.graphics.beginFill(0xFFFFFF);
			this.graphics.drawRect(-2.5, 0, 5, 20);
			this.graphics.endFill();
		}
		private function eFrameEvents(e:Event):void{

			if(_root.gameOver){//destroy this if game is over
				this.removeEventListener(Event.ENTER_FRAME, eFrameEvents);
				MovieClip(this.parent).removeChild(this);
			}
		}
	}
}

This will be only the beginning of what we program into the Turret. Next, we have to define a function in the _root of the document that will create the turrets. Add this code to the bottom in your source .fla file:

function makeTurret(xValue:int,yValue:int):void{//this will need to be told the x and y values
	var turret:Turret = new Turret();//creating a variable to hold the Turret
	//changing the coordinates
	turret.x = xValue+12.5;
	turret.y = yValue+12.5;
	addChild(turret);//add it to the stage
}

Now, we can finally make it so the turret is created when the user clicks on an empty block. Find the function thisClick() in “EmptyBlock.as”. Add the following code to that:

_root.makeTurret(this.x,this.y);//make the turret
//remove all the listeners so it can't be clicked on again
this.buttonMode = false;
this.graphics.beginFill(0x333333);
this.graphics.drawRect(0,0,25,25);
this.graphics.endFill();
this.removeEventListener(MouseEvent.MOUSE_OVER, thisMouseOver);
this.removeEventListener(MouseEvent.MOUSE_OUT, thisMouseOut);
this.removeEventListener(MouseEvent.CLICK, thisClick);

Now, if you test out the game, a turret should appear whenever you click on any empty block!

Well, that’s it for this tutorial. Next time, we’ll add enemies and program them!