Adds power-ups to demo game

examples/game/lib/game_demo_node.dart

@@ -45,6 +45,7 @@ class GameDemoNode extends NodeWithSize {
     _objectFactory = new GameObjectFactory(_spritesGame, _sounds, _level, _playerState);
 
     _level.ship = new Ship(_objectFactory);
+    _level.ship.setupActions();
     _level.addChild(_level.ship);
 
     // Add the joystick
@@ -111,7 +112,7 @@ class GameDemoNode extends NodeWithSize {
     // Add shots
     if (_framesToFire == 0 && _joystick.isDown && !_gameOver) {
       fire();
-      _framesToFire = _framesBetweenShots;
+      _framesToFire = (_playerState.speedLaserActive) ? _framesBetweenShots ~/ 2 : _framesBetweenShots;
     }
     if (_framesToFire > 0) _framesToFire--;
 
@@ -158,9 +159,13 @@ class GameDemoNode extends NodeWithSize {
     for (Node node in nodes) {
       if (node is GameObject && node.canDamageShip) {
         if (node.collidingWith(_level.ship)) {
-          // The ship was hit :(
-          killShip();
-          _level.ship.visible = false;
+          if (_playerState.shieldActive) {
+            // Hit, but saved by the shield!
+            node.destroy();
+          } else {
+            // The ship was hit :(
+            killShip();
+          }
         }
       } else if (node is GameObject && node.canBeCollected) {
         if (node.collidingWith(_level.ship)) {
@@ -209,14 +214,24 @@ class GameDemoNode extends NodeWithSize {
   }
 
   void fire() {
-    Laser shot0 = new Laser(_objectFactory);
+    Laser shot0 = new Laser(_objectFactory, -90.0);
     shot0.position = _level.ship.position + new Offset(17.0, -10.0);
     _level.addChild(shot0);
 
-    Laser shot1 = new Laser(_objectFactory);
+    Laser shot1 = new Laser(_objectFactory, -90.0);
     shot1.position = _level.ship.position + new Offset(-17.0, -10.0);
     _level.addChild(shot1);
 
+    if (_playerState.sideLaserActive) {
+      Laser shot2 = new Laser(_objectFactory, 0.0);
+      shot2.position = _level.ship.position + new Offset(17.0, -10.0);
+      _level.addChild(shot2);
+
+      Laser shot3 = new Laser(_objectFactory, 180.0);
+      shot3.position = _level.ship.position + new Offset(-17.0, -10.0);
+      _level.addChild(shot3);
+    }
+
     _effectPlayer.play(_sounds["laser"]);
   }
 

examples/game/lib/game_object_factory.dart

@@ -3,6 +3,7 @@ part of game;
 enum GameObjectType {
   asteroidBig,
   asteroidSmall,
+  asteroidPowerUp,
   enemyScout,
   enemyDestroyer,
   coin,
@@ -19,6 +20,7 @@ class GameObjectFactory {
   void addAsteroids(int numAsteroids, double yPos, double distribution) {
     for (int i = 0; i < numAsteroids; i++) {
       GameObjectType type = (randomDouble() < distribution) ? GameObjectType.asteroidBig : GameObjectType.asteroidSmall;
+      if (i == 0) type = GameObjectType.asteroidPowerUp;
       Point pos = new Point(randomSignedDouble() * 160.0,
                             yPos + _chunkSpacing * randomDouble());
       addGameObject(type, pos);
@@ -45,6 +47,8 @@ class GameObjectFactory {
       obj = new AsteroidBig(this);
     else if (type == GameObjectType.asteroidSmall)
       obj = new AsteroidSmall(this);
+    else if (type == GameObjectType.asteroidPowerUp)
+      obj = new AsteroidPowerUp(this);
     else if (type == GameObjectType.enemyScout)
       obj = new EnemyScout(this);
     else if (type == GameObjectType.enemyDestroyer)

examples/game/lib/game_objects.dart

@@ -42,7 +42,7 @@ abstract class GameObject extends Node {
         parent.addChild(explo);
       }
 
-      PowerUp powerUp = createPowerUp();
+      Collectable powerUp = createPowerUp();
       if (powerUp != null) {
         powerUp.position = position;
         powerUp.setupActions();
@@ -71,7 +71,7 @@ abstract class GameObject extends Node {
     return null;
   }
 
-  PowerUp createPowerUp() {
+  Collectable createPowerUp() {
     return null;
   }
 
@@ -93,8 +93,13 @@ class Ship extends GameObject {
     _sprt.scale = 0.3;
     _sprt.rotation = -90.0;
     addChild(_sprt);
-    radius = 20.0;
 
+    _sprtShield = new Sprite(f.sheet["shield.png"]);
+    _sprtShield.scale = 0.35;
+    _sprtShield.transferMode = sky.TransferMode.plus;
+    addChild(_sprtShield);
+
+    radius = 20.0;
     canBeDamaged = false;
     canDamageShip = false;
 
@@ -103,6 +108,7 @@ class Ship extends GameObject {
   }
 
   Sprite _sprt;
+  Sprite _sprtShield;
 
   void applyThrust(Point joystickValue, double scroll) {
     Point oldPos = position;
@@ -113,29 +119,51 @@ class Ship extends GameObject {
       GameMath.filter(oldPos.x, target.x, filterFactor),
       GameMath.filter(oldPos.y, target.y, filterFactor));
   }
+
+  void setupActions() {
+    ActionTween rotate = new ActionTween((a) => _sprtShield.rotation = a, 0.0, 360.0, 1.0);
+    _sprtShield.actions.run(new ActionRepeatForever(rotate));
+  }
+
+  void update(double dt) {
+    // Update shield
+    if (f.playerState.shieldActive) {
+      if (f.playerState.shieldDeactivating)
+        _sprtShield.visible = !_sprtShield.visible;
+      else
+        _sprtShield.visible = true;
+    } else {
+      _sprtShield.visible = false;
+    }
+  }
 }
 
 class Laser extends GameObject {
   double impact = 1.0;
 
-  Laser(GameObjectFactory f) : super(f) {
+  Laser(GameObjectFactory f, double r) : super(f) {
     // Add sprite
     _sprt = new Sprite(f.sheet["explosion_particle.png"]);
     _sprt.scale = 0.5;
     _sprt.colorOverlay = new Color(0xff95f4fb);
     _sprt.transferMode = sky.TransferMode.plus;
+    _sprt.rotation = r + 90.0;
     addChild(_sprt);
     radius = 10.0;
     removeLimit = 640.0;
 
+
     canDamageShip = false;
     canBeDamaged = false;
+
+    _offset = new Offset(math.cos(radians(r)) * 10.0, math.sin(radians(r)) * 10.0);
   }
 
   Sprite _sprt;
+  Offset _offset;
 
   void move() {
-    position += new Offset(0.0, -10.0);
+    position += _offset;
   }
 }
 
@@ -178,7 +206,7 @@ abstract class Asteroid extends Obstacle {
     _sprt.colorOverlay = colorForDamage(d, maxDamage);
   }
 
-  PowerUp createPowerUp() {
+  Collectable createPowerUp() {
     return new Coin(f);
   }
 }
@@ -203,6 +231,14 @@ class AsteroidSmall extends Asteroid {
   }
 }
 
+class AsteroidPowerUp extends AsteroidBig {
+  AsteroidPowerUp(GameObjectFactory f) : super(f);
+
+  Collectable createPowerUp() {
+    return new PowerUp(f, nextPowerUpType());
+  }
+}
+
 class EnemyScout extends Obstacle {
   EnemyScout(GameObjectFactory f) : super(f) {
     _sprt = new Sprite(f.sheet["enemy_scout_0.png"]);
@@ -256,7 +292,7 @@ class EnemyScout extends Obstacle {
     actions.run(new ActionRepeatForever(spline));
   }
 
-  PowerUp createPowerUp() {
+  Collectable createPowerUp() {
     return new Coin(f);
   }
 
@@ -286,7 +322,7 @@ class EnemyDestroyer extends Obstacle {
     actions.run(new ActionRepeatForever(circle));
   }
 
-  PowerUp createPowerUp() {
+  Collectable createPowerUp() {
     return new Coin(f);
   }
 
@@ -337,15 +373,17 @@ class EnemyLaser extends Obstacle {
   }
 }
 
-class PowerUp extends GameObject {
-  PowerUp(GameObjectFactory f) : super(f) {
+class Collectable extends GameObject {
+  Collectable(GameObjectFactory f) : super(f) {
     canDamageShip = false;
     canBeDamaged = false;
     canBeCollected = true;
+
+    zPosition = 20.0;
   }
 }
 
-class Coin extends PowerUp {
+class Coin extends Collectable {
   Coin(GameObjectFactory f) : super(f) {
     _sprt = new Sprite(f.sheet["coin.png"]);
     _sprt.scale = 0.7;
@@ -354,9 +392,14 @@ class Coin extends PowerUp {
     radius = 7.5;
   }
 
-  setupActions() {
+  void setupActions() {
+    // Rotate
     ActionTween rotate = new ActionTween((a) => _sprt.rotation = a, 0.0, 360.0, 1.0);
     actions.run(new ActionRepeatForever(rotate));
+
+    // Fade in
+    ActionTween fadeIn = new ActionTween((a) => _sprt.opacity = a, 0.0, 1.0, 0.6);
+    actions.run(fadeIn);
   }
 
   Sprite _sprt;
@@ -366,3 +409,51 @@ class Coin extends PowerUp {
     super.collect();
   }
 }
+
+enum PowerUpType {
+  shield,
+  speedLaser,
+  sideLaser,
+}
+
+List<PowerUpType> _powerUpTypes = new List.from(PowerUpType.values);
+int _lastPowerUp = _powerUpTypes.length;
+
+PowerUpType nextPowerUpType() {
+  if (_lastPowerUp >= _powerUpTypes.length) {
+     _powerUpTypes.shuffle();
+     _lastPowerUp = 0;
+  }
+
+  PowerUpType type = _powerUpTypes[_lastPowerUp];
+  _lastPowerUp++;
+
+  return type;
+}
+
+class PowerUp extends Collectable {
+  PowerUp(GameObjectFactory f, this.type) : super(f) {
+    _sprt = new Sprite(f.sheet["coin.png"]);
+    _sprt.scale = 1.2;
+    addChild(_sprt);
+
+    radius = 10.0;
+  }
+
+  Sprite _sprt;
+  PowerUpType type;
+
+  void setupActions() {
+    ActionTween rotate = new ActionTween((a) => _sprt.rotation = a, 0.0, 360.0, 1.0);
+    actions.run(new ActionRepeatForever(rotate));
+
+    // Fade in
+    ActionTween fadeIn = new ActionTween((a) => _sprt.opacity = a, 0.0, 1.0, 0.6);
+    actions.run(fadeIn);
+  }
+
+  void collect() {
+    f.playerState.activatePowerUp(type);
+    super.collect();
+  }
+}

examples/game/lib/player_state.dart

@@ -71,6 +71,26 @@ class PlayerState extends Node {
     addChild(sprt);
   }
 
+  void activatePowerUp(PowerUpType type) {
+    if (type == PowerUpType.shield) {
+      _shieldFrames += 300;
+    } else if (type == PowerUpType.sideLaser) {
+      _sideLaserFrames += 300;
+    } else if (type == PowerUpType.speedLaser) {
+      _speedLaserFrames += 300;
+    }
+  }
+
+  int _shieldFrames = 0;
+  bool get shieldActive => _shieldFrames > 0;
+  bool get shieldDeactivating => _shieldFrames > 0 && _shieldFrames < 60;
+
+  int _sideLaserFrames = 0;
+  bool get sideLaserActive => _sideLaserFrames > 0;
+
+  int _speedLaserFrames = 0;
+  bool get speedLaserActive => _speedLaserFrames > 0;
+
   void flashBgSprite(Sprite sprt) {
     sprt.actions.stopAll();
     ActionTween flash = new ActionTween(
@@ -80,6 +100,12 @@ class PlayerState extends Node {
       0.3);
     sprt.actions.run(flash);
   }
+
+  void update(double dt) {
+    if (_shieldFrames > 0) _shieldFrames--;
+    if (_sideLaserFrames > 0) _sideLaserFrames--;
+    if (_speedLaserFrames > 0) _speedLaserFrames--;
+  }
 }
 
 class ScoreDisplay extends Node {