Adds power ups to demo game, and some minor refactoring to support the addition

examples/game/lib/game_demo_node.dart

@@ -38,7 +38,11 @@ class GameDemoNode extends NodeWithSize {
     _level = new Level();
     _gameScreen.addChild(_level);
 
-    _objectFactory = new GameObjectFactory(_spritesGame, _sounds, _level);
+    // Add heads up display
+    _playerState = new PlayerState(_spritesUI);
+    addChild(_playerState);
+
+    _objectFactory = new GameObjectFactory(_spritesGame, _sounds, _level, _playerState);
 
     _level.ship = new Ship(_objectFactory);
     _level.addChild(_level.ship);
@@ -47,10 +51,6 @@ class GameDemoNode extends NodeWithSize {
     _joystick = new VirtualJoystick();
     _gameScreen.addChild(_joystick);
 
-    // Add HUD
-    _hud = new Hud(_spritesUI);
-    addChild(_hud);
-
     // Add initial game objects
     addObjects();
   }
@@ -76,7 +76,7 @@ class GameDemoNode extends NodeWithSize {
   StarField _starField;
   RepeatedImage _background;
   RepeatedImage _nebula;
-  Hud _hud;
+  PlayerState _playerState;
 
   // Game properties
   double _scrollSpeed = 2.0;
@@ -147,7 +147,7 @@ class GameDemoNode extends NodeWithSize {
       for (GameObject damageable in damageables) {
         if (laser.collidingWith(damageable)) {
           // Hit something that can take damage
-          _hud.score += damageable.addDamage(laser.impact);
+          damageable.addDamage(laser.impact);
           laser.destroy();
         }
       }
@@ -162,6 +162,11 @@ class GameDemoNode extends NodeWithSize {
           killShip();
           _level.ship.visible = false;
         }
+      } else if (node is GameObject && node.canBeCollected) {
+        if (node.collidingWith(_level.ship)) {
+          // The ship ran over something collectable
+          node.removeFromParent();
+        }
       }
     }
   }
@@ -235,7 +240,7 @@ class GameDemoNode extends NodeWithSize {
     _gameOver = true;
 
     // Return to main scene and report the score back in 2 seconds
-    new Timer(new Duration(seconds: 2), () { _gameOverCallback(_hud.score); });
+    new Timer(new Duration(seconds: 2), () { _gameOverCallback(_playerState.score); });
   }
 }
 
@@ -256,14 +261,16 @@ enum GameObjectType {
   asteroidBig,
   asteroidSmall,
   movingEnemy,
+  coin,
 }
 
 class GameObjectFactory {
-  GameObjectFactory(this.sheet, this.sounds, this.level);
+  GameObjectFactory(this.sheet, this.sounds, this.level, this.playerState);
 
   SpriteSheet sheet;
   Map<String,SoundEffect> sounds;
   Level level;
+  PlayerState playerState;
 
   void addAsteroids(int numAsteroids, double yPos, double distribution) {
     for (int i = 0; i < numAsteroids; i++) {
@@ -290,6 +297,8 @@ class GameObjectFactory {
       obj = new AsteroidSmall(this);
     else if (type == GameObjectType.movingEnemy)
       obj = new MovingEnemy(this);
+    else if (type == GameObjectType.coin)
+      obj = new Coin(this);
 
     obj.position = pos;
     obj.setupActions();
@@ -298,7 +307,7 @@ class GameObjectFactory {
   }
 }
 
-class Hud extends Node {
+class PlayerState extends Node {
   SpriteSheet sheet;
   Sprite sprtBgScore;
 
@@ -312,7 +321,7 @@ class Hud extends Node {
     _dirtyScore = true;
   }
 
-  Hud(this.sheet) {
+  PlayerState(this.sheet) {
     position = new Point(310.0, 10.0);
     scale = 0.6;
 

examples/game/lib/game_objects.dart

 part of game;
 
 abstract class GameObject extends Node {
+  GameObject(this.f);
+
   double radius = 0.0;
   double removeLimit = 1280.0;
   bool canDamageShip = true;
   bool canBeDamaged = true;
+  bool canBeCollected = false;
   double maxDamage = 3.0;
   double damage = 0.0;
 
+  final GameObjectFactory f;
+
   Paint _paintDebug = new Paint()
     ..color=new Color(0xffff0000)
     ..strokeWidth = 1.0
@@ -37,25 +42,35 @@ abstract class GameObject extends Node {
         parent.addChild(explo);
       }
 
+      PowerUp powerUp = createPowerUp();
+      if (powerUp != null) {
+        powerUp.position = position;
+        powerUp.setupActions();
+        parent.addChild(powerUp);
+      }
+
       removeFromParent();
     }
   }
 
-  int addDamage(double d) {
-    if (!canBeDamaged) return 0;
+  void addDamage(double d) {
+    if (!canBeDamaged) return;
 
     damage += d;
     if (damage >= maxDamage) {
       destroy();
-      return (maxDamage * 10).ceil();
+      f.playerState.score += (maxDamage * 10).ceil();
     }
-    return 10;
   }
 
   Explosion createExplosion() {
     return null;
   }
 
+  PowerUp createPowerUp() {
+    return null;
+  }
+
   void paint(PaintingCanvas canvas) {
     if (_drawDebug) {
       canvas.drawCircle(Point.origin, radius, _paintDebug);
@@ -68,7 +83,7 @@ abstract class GameObject extends Node {
 }
 
 class Ship extends GameObject {
-  Ship(GameObjectFactory f) {
+  Ship(GameObjectFactory f) : super(f) {
     // Add main ship sprite
     _sprt = new Sprite(f.sheet["ship.png"]);
     _sprt.scale = 0.3;
@@ -99,7 +114,7 @@ class Ship extends GameObject {
 class Laser extends GameObject {
   double impact = 1.0;
 
-  Laser(GameObjectFactory f) {
+  Laser(GameObjectFactory f) : super(f) {
     // Add sprite
     _sprt = new Sprite(f.sheet["laser.png"]);
     _sprt.scale = 0.3;
@@ -121,14 +136,13 @@ class Laser extends GameObject {
 
 abstract class Obstacle extends GameObject {
 
-  Obstacle(this._f);
+  Obstacle(GameObjectFactory f) : super(f);
 
   double explosionScale = 1.0;
-  GameObjectFactory _f;
 
   Explosion createExplosion() {
-    SoundEffectPlayer.sharedInstance().play(_f.sounds["explosion"]);
-    Explosion explo = new Explosion(_f.sheet);
+    SoundEffectPlayer.sharedInstance().play(f.sounds["explosion"]);
+    Explosion explo = new Explosion(f.sheet);
     explo.scale = explosionScale;
     return explo;
   }
@@ -154,6 +168,10 @@ abstract class Asteroid extends Obstacle {
     int alpha = ((200.0 * d) ~/ maxDamage).clamp(0, 200);
     _sprt.colorOverlay = new Color.fromARGB(alpha, 255, 3, 86);
   }
+
+  PowerUp createPowerUp() {
+    return new Coin(f);
+  }
 }
 
 class AsteroidBig extends Asteroid {
@@ -181,7 +199,7 @@ class MovingEnemy extends Obstacle {
     _sprt = new Sprite(f.sheet["ship.png"]);
     _sprt.scale = 0.2;
     radius = 12.0;
-    maxDamage = 2.0;
+    maxDamage = 1.0;
     addChild(_sprt);
 
     constraints = [new ConstraintRotationToMovement(dampening: 0.5)];
@@ -231,3 +249,29 @@ class MovingEnemy extends Obstacle {
 
   Sprite _sprt;
 }
+
+class PowerUp extends GameObject {
+  PowerUp(GameObjectFactory f) : super(f) {
+    canDamageShip = false;
+    canBeDamaged = false;
+    canBeCollected = true;
+  }
+}
+
+class Coin extends PowerUp {
+  Coin(GameObjectFactory f) : super(f) {
+    _sprt = new Sprite(f.sheet["shield.png"]);
+    _sprt.transferMode = sky.TransferMode.plus;
+    _sprt.size = new Size(15.0, 15.0);
+    addChild(_sprt);
+
+    radius = 7.5;
+  }
+
+  setupActions() {
+    ActionTween rotate = new ActionTween((a) => _sprt.rotation = a, 0.0, 360.0, 1.0);
+    actions.run(new ActionRepeatForever(rotate));
+  }
+
+  Sprite _sprt;
+}