Adds counting of coins in demo game

examples/game/lib/game_demo_node.dart

@@ -39,7 +39,7 @@ class GameDemoNode extends NodeWithSize {
     _gameScreen.addChild(_level);
 
     // Add heads up display
-    _playerState = new PlayerState(_spritesUI);
+    _playerState = new PlayerState(_spritesUI, _spritesGame);
     addChild(_playerState);
 
     _objectFactory = new GameObjectFactory(_spritesGame, _sounds, _level, _playerState);
@@ -165,7 +165,7 @@ class GameDemoNode extends NodeWithSize {
       } else if (node is GameObject && node.canBeCollected) {
         if (node.collidingWith(_level.ship)) {
           // The ship ran over something collectable
-          node.removeFromParent();
+          node.collect();
         }
       }
     }

examples/game/lib/game_objects.dart

@@ -53,6 +53,10 @@ abstract class GameObject extends Node {
     }
   }
 
+  void collect() {
+    removeFromParent();
+  }
+
   void addDamage(double d) {
     if (!canBeDamaged) return;
 
@@ -263,6 +267,7 @@ class Coin extends PowerUp {
     _sprt = new Sprite(f.sheet["shield.png"]);
     _sprt.transferMode = sky.TransferMode.plus;
     _sprt.size = new Size(15.0, 15.0);
+    _sprt.colorOverlay = new Color(0xffffff00);
     addChild(_sprt);
 
     radius = 7.5;
@@ -274,4 +279,9 @@ class Coin extends PowerUp {
   }
 
   Sprite _sprt;
+
+  void collect() {
+    f.playerState.addCoin(this);
+    super.collect();
+  }
 }

examples/game/lib/player_state.dart

 part of game;
 
 class PlayerState extends Node {
-  SpriteSheet sheet;
-  Sprite sprtBgScore;
+  PlayerState(this._sheetUI, this._sheetGame) {
+    // Score display
+    Sprite sprtBgScore = new Sprite(_sheetUI["scoreboard.png"]);
+    sprtBgScore.pivot = new Point(1.0, 0.0);
+    sprtBgScore.scale = 0.35;
+    sprtBgScore.position = new Point(310.0, 10.0);
+    addChild(sprtBgScore);
+
+    _scoreDisplay = new ScoreDisplay(_sheetUI);
+    _scoreDisplay.position = new Point(-13.0, 49.0);
+    sprtBgScore.addChild(_scoreDisplay);
+
+    // Coin display
+    Sprite sprtBgCoins = new Sprite(_sheetUI["scoreboard.png"]);
+    sprtBgCoins.pivot = new Point(1.0, 0.0);
+    sprtBgCoins.scale = 0.35;
+    sprtBgCoins.position = new Point(170.0, 10.0);
+    addChild(sprtBgCoins);
+
+    _coinDisplay = new ScoreDisplay(_sheetUI);
+    _coinDisplay.position = new Point(-13.0, 49.0);
+    sprtBgCoins.addChild(_coinDisplay);
+  }
+
+  final SpriteSheet _sheetUI;
+  final SpriteSheet _sheetGame;
+
+  ScoreDisplay _scoreDisplay;
+  ScoreDisplay _coinDisplay;
+
+  int get score => _scoreDisplay.score;
+
+  set score(int score) {
+    _scoreDisplay.score = score;
+  }
+
+  int get coins => _coinDisplay.score;
+
+  void addCoin(Coin c) {
+    // Animate coin to the top of the screen
+    Point startPos = convertPointFromNode(Point.origin, c);
+    Point finalPos = new Point(10.0, 10.0);
+    Point middlePos = new Point((startPos.x + finalPos.x) / 2.0 + 50.0,
+      (startPos.y + finalPos.y) / 2.0);
+
+    List<Point> path = [startPos, middlePos, finalPos];
+
+    Sprite sprt = new Sprite(_sheetGame["shield.png"]);
+    sprt.size = new Size(15.0, 15.0);
+    sprt.transferMode = sky.TransferMode.plus;
+    sprt.colorOverlay = new Color(0xffffff00);
+    ActionSpline spline = new ActionSpline((a) => sprt.position = a, path, 0.5);
+    spline.tension = 0.25;
+    sprt.actions.run(new ActionSequence([
+      spline,
+      new ActionRemoveNode(sprt),
+      new ActionCallFunction(() { _coinDisplay.score += 1; })
+    ]));
+
+    addChild(sprt);
+  }
+}
+
+class ScoreDisplay extends Node {
+  ScoreDisplay(this._sheetUI);
 
-  bool _dirtyScore = true;
   int _score = 0;
 
   int get score => _score;
@@ -14,29 +76,21 @@ class PlayerState extends Node {
     _dirtyScore = true;
   }
 
-  PlayerState(this.sheet) {
-    position = new Point(310.0, 10.0);
-    scale = 0.6;
+  SpriteSheet _sheetUI;
 
-    sprtBgScore = new Sprite(sheet["scoreboard.png"]);
-    sprtBgScore.pivot = new Point(1.0, 0.0);
-    sprtBgScore.scale = 0.6;
-    addChild(sprtBgScore);
-  }
+  bool _dirtyScore = true;
 
   void update(double dt) {
-    // Update score
     if (_dirtyScore) {
-
-      sprtBgScore.removeAllChildren();
+      removeAllChildren();
 
       String scoreStr = _score.toString();
-      double xPos = -50.0;
+      double xPos = -37.0;
       for (int i = scoreStr.length - 1; i >= 0; i--) {
         String numStr = scoreStr.substring(i, i + 1);
-        Sprite numSprt = new Sprite(sheet["number_$numStr.png"]);
-        numSprt.position = new Point(xPos, 49.0);
-        sprtBgScore.addChild(numSprt);
+        Sprite numSprt = new Sprite(_sheetUI["number_$numStr.png"]);
+        numSprt.position = new Point(xPos, 0.0);
+        addChild(numSprt);
         xPos -= 37.0;
       }
       _dirtyScore = false;