Adds display of last score to demo game

packages/flutter/example/game/lib/game_demo.dart

@@ -9,4 +9,6 @@ import 'package:sky/widgets/widget.dart';
 import 'package:sky/widgets/navigator.dart';
 import 'package:vector_math/vector_math_64.dart';
 
+import '../main.dart';
+
 part 'game_demo_world.dart';

packages/flutter/example/game/lib/game_demo_world.dart

@@ -348,6 +348,7 @@ class GameDemoWorld extends NodeWithSize {
 
     // Set game over
     _isGameOver = true;
+    lastScore = _hud.score;
 
     // Remove the ship
     _ship.visible = false;

packages/flutter/example/game/main.dart

@@ -5,6 +5,7 @@
 import 'package:sky/mojo/asset_bundle.dart';
 import 'package:sky/theme/colors.dart' as colors;
 import 'package:sky/rendering/object.dart';
+import 'package:sky/painting/text_style.dart';
 import 'package:sky/widgets/basic.dart';
 import 'package:sky/widgets/button_base.dart';
 import 'package:sky/widgets/navigator.dart';
@@ -93,7 +94,8 @@ class GameDemoApp extends App {
     return new Stack([
       new SpriteWidget(new MainScreenBackground()),
       new Center(
-        child: new TextureButton(
+        child: new Flex([
+          new TextureButton(
             onPressed: () {
               _game = new GameDemoWorld(
                 _app,
@@ -108,12 +110,21 @@ class GameDemoApp extends App {
             textureDown: _spriteSheetUI["btn_play_down.png"],
             width: 128.0,
             height: 128.0
+          ),
+          new Text(
+            "Last Score: $lastScore",
+            style: new TextStyle(fontSize:20.0)
           )
+        ],
+        direction: FlexDirection.vertical,
+        justifyContent: FlexJustifyContent.center)
       )
     ]);
   }
 }
 
+int lastScore = 0;
+
 class TextureButton extends ButtonBase {
   TextureButton({
     Key key,
@@ -156,6 +167,7 @@ class TextureButton extends ButtonBase {
     if (texture == null)
       return;
 
+    canvas.save();
     if (highlight && textureDown != null) {
       // Draw down state
       canvas.scale(size.width / textureDown.size.width, size.height / textureDown.size.height);
@@ -165,6 +177,7 @@ class TextureButton extends ButtonBase {
       canvas.scale(size.width / texture.size.width, size.height / texture.size.height);
       texture.drawTexture(canvas, Point.origin, new Paint());
     }
+    canvas.restore();
   }
 }