package
{
import flash.events.*;
import flash.geom.*;
import flash.media.*;
import flash.net.*;
import flash.utils.*;
import mx.collections.ArrayCollection;
import mx.core.*;
public class Level
{
protected static var instance:Level = null;
protected static const TimeBetweenLevelElements:Number = 2;
protected static const TimeBetweenEnemies:Number = 3;
protected static const TimeBetweenClouds:Number = 2.5;
protected static const TimeToLevelEnd:Number = 2;
protected var timeToNextLevelElement:Number = 0;
protected var levelElementGraphics:ArrayCollection = new ArrayCollection();
protected var timeToNextEnemy:Number = 0;
protected var enemyElementGraphics:ArrayCollection = new ArrayCollection();
protected var timeToNextCloud:Number = 0;
protected var timeToLevelEnd:Number = 0;
public var levelEnd:Boolean = false;
static public function get Instance():Level
{
if ( instance == null )
instance = new Level();
return instance;
}
public function Level(caller:Function = null )
{
if ( Level.instance != null )
throw new Error( "Only one Singleton instance should be instantiated" );
levelElementGraphics. addItem(ResourceManager.SmallIslandGraphics);
levelElementGraphics. addItem(ResourceManager.BigIslandGraphics);
levelElementGraphics. addItem(ResourceManager.VolcanoIslandGraphics);
enemyElementGraphics. addItem(ResourceManager.SmallBluePlaneGraphics);
enemyElementGraphics. addItem(ResourceManager.SmallGreenPlaneGraphics);
enemyElementGraphics. addItem(ResourceManager.SmallWhitePlaneGraphics);
}
public function startup():void
{
timeToNextLevelElement = 0;
new Player().startupPlayer();
timeToLevelEnd = TimeToLevelEnd;
levelEnd = false;
}
public function shutdown():void
{
}
public function enterFrame(dt:Number):void
{
// add a background element
timeToNextLevelElement -= dt;
if (timeToNextLevelElement <= 0)
{
timeToNextLevelElement = TimeBetweenLevelElements;
var graphics:GraphicsResource = levelElementGraphics.getItemAt(MathUtils.randomInteger(0, levelElementGraphics.length)) as GraphicsResource;
var backgroundLevelElement:BackgroundLevelElement = BackgroundLevelElement.pool.ItemFromPool as BackgroundLevelElement;
backgroundLevelElement.startupBackgroundLevelElement(
graphics,
new Point(Math.random() * Application.application.width, -graphics.bitmap.height),
ZOrders.BackgoundZOrder,
50);
}
// add an emeny
timeToNextEnemy -= dt;
if (timeToNextEnemy <= 0)
{
timeToNextEnemy = TimeBetweenEnemies;
var enemygraphics:GraphicsResource = enemyElementGraphics.getItemAt(MathUtils.randomInteger(0, enemyElementGraphics.length)) as GraphicsResource;
var enemy:Enemy = Enemy.pool.ItemFromPool as Enemy;
enemy.startupBasicEnemy(
enemygraphics,
new Point(Math.random() * Application.application.width, -enemygraphics.bitmap.height),
55);
}
// add cloud
timeToNextCloud -= dt;
if (timeToNextCloud <= dt)
{
timeToNextCloud = TimeBetweenClouds;
var cloudBackgroundLevelElement:BackgroundLevelElement = BackgroundLevelElement.pool.ItemFromPool as BackgroundLevelElement;
cloudBackgroundLevelElement. startupBackgroundLevelElement(
ResourceManager.CloudGraphics,
new Point(Math.random() * Application.application.width, -ResourceManager.CloudGraphics.bitmap.height),
ZOrders.CloudsBelowZOrder,
75);
}
if (levelEnd)
timeToLevelEnd -= dt;
if (timeToLevelEnd <= 0)
Application.application.currentState = "MainMenu";
}
}
}
The changes to the Level class simply allow it to be notified when the Player dies through the levelEnd property. When set to true a count down beings in enterFrame using the timeToLevelEnd property, and when timeToLevelEnd reaches 0 the state is changed back to MainMenu which drops us back to the main menu screen.
Collision detection is essential in any action game. In this article we have implemented a simple, but effective, collision detection system which allows the player to now interact with other elements in the game, like being able to shoot the enemies. Unfortunately at the moment actualy destroying an enemy is quite unsatisfying because they just disappear. In part 7 of the series we will add some animations to the game, and with that some nice explosions.
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