fix!: Update should be called before render in first tick

packages/flame/lib/src/game/game_widget/game_widget.dart

@@ -196,6 +196,9 @@ class GameWidgetState<T extends Game> extends State<GameWidget<T>> {
  await onLoad;
  }
  game.mount();
+ if (!game.paused) {
+ game.update(0);
+ }
  })();
 
  Future<void>? _loaderFuture;
@@ -362,6 +365,12 @@ class GameWidgetState<T extends Game> extends State<GameWidget<T>> {
  Container();
  }
  currentGame.onGameResize(size);
+ // This should only be called if the game has already been
+ // loaded (in the case of resizing for example), since
+ // update otherwise should be called after onMount.
+ if (!currentGame.paused && currentGame.isAttached) {
+ currentGame.update(0);
+ }
  return FutureBuilder(
  future: loaderFuture,
  builder: (_, snapshot) {

packages/flame/test/components/mixins/snapshot_test.dart

@@ -16,8 +16,8 @@ void main() {
  'Snapshot should be created once',
  _SnapshotTestGame.new,
  (game) async {
- final snapshotComponent = game.snapshotComponent;
  await game.ready();
+ final snapshotComponent = game.snapshotComponent;
 
  // Wait a few frames
  final canvas = Canvas(PictureRecorder());
@@ -39,8 +39,8 @@ void main() {
  'Should render normally when renderSnapshot is false',
  () => _SnapshotTestGame(renderSnapshot: false),
  (game) async {
- final snapshotComponent = game.snapshotComponent;
  await game.ready();
+ final snapshotComponent = game.snapshotComponent;
 
  // Wait a few frames
  const framesToWait = 5;
@@ -73,14 +73,15 @@ void main() {
  'Should generate a snapshot when takeSnapshot is called',
  (tester) async {
  final game = _SnapshotTestGame(renderSnapshot: false);
- final snapshotComponent = game.snapshotComponent;
  const framesToWait = 5;
+ late final _MockSnapshotComponent snapshotComponent;
 
  await tester.runAsync(() async {
  final widget = GameWidget(game: game);
  await tester.pumpWidget(widget);
  await tester.pump();
  await game.ready();
+ snapshotComponent = game.snapshotComponent;
 
  // Wait a few frames
  final recorder = PictureRecorder();
@@ -116,13 +117,14 @@ void main() {
  'Should generate a transformed image',
  (tester) async {
  final game = _SnapshotTestGame(renderSnapshot: false);
- final snapshotComponent = game.snapshotComponent;
+ late final _MockSnapshotComponent snapshotComponent;
 
  await tester.runAsync(() async {
  final widget = GameWidget(game: game);
  await tester.pumpWidget(widget);
  await tester.pump();
  await game.ready();
+ snapshotComponent = game.snapshotComponent;
 
  // Force a frame
  final canvas = Canvas(PictureRecorder());
@@ -173,8 +175,12 @@ void main() {
 
 class _SnapshotTestGame extends FlameGame {
  late final _MockSnapshotComponent snapshotComponent;
+ bool renderSnapshot;
 
- _SnapshotTestGame({bool renderSnapshot = true}) {
+ _SnapshotTestGame({this.renderSnapshot = true});
+
+ @override
+ Future<void> onLoad() async {
  // Add a snapshot-enabled component that has it's own rendered content
  snapshotComponent = _MockSnapshotComponent()
  ..size = Vector2(200, 200)

packages/flame/test/game/game_widget/game_widget_lifecycle_test.dart

@@ -25,6 +25,18 @@ class _MyGame extends FlameGame {
  events.add('onMount');
  }
 
+ @override
+ void update(double dt) {
+ super.update(dt);
+ events.add('update');
+ }
+
+ @override
+ void render(Canvas canvas) {
+ super.render(canvas);
+ events.add('render');
+ }
+
  @override
  void onRemove() {
  super.onRemove();
@@ -207,12 +219,27 @@ void main() {
  state.causeResize();
 
  await tester.pump();
- expect(events, ['onGameResize']); // no onRemove
+ expect(events, ['onGameResize', 'update', 'render']); // no onRemove
  final game =
  tester.allWidgets.whereType<GameWidget<_MyGame>>().first.game;
  expect(game?.children, everyElement((Component c) => c.parent == game));
  });
 
+ testWidgets('update is not called when game is paused', (tester) async {
+ final events = <String>[];
+ await tester.pumpWidget(_MyContainer(events));
+
+ events.clear();
+ tester.allWidgets
+ .whereType<GameWidget<_MyGame>>()
+ .first
+ .game
+ ?.pauseEngine();
+ await tester.pump();
+ await tester.pump();
+ expect(events, ['render']);
+ });
+
  testWidgets('all events are executed in the correct order', (tester) async {
  final events = <String>[];
  await tester.pumpWidget(_MyApp(events));
@@ -239,10 +266,15 @@ void main() {
  'onGameResize',
  'onLoad',
  'onMount',
+ 'update',
+ 'render',
+ 'update',
  'onRemove',
  'onDispose',
  'onGameResize',
  'onMount',
+ 'update',
+ 'render',
  ],
  );
  });

packages/flame/test/game/game_widget/game_widget_pause_test.dart

@@ -52,15 +52,21 @@ class _WrapperState extends State<_Wrapper> {
 }
 
 class _MyGame extends FlameGame {
- int callCount = 0;
+ int updateCount = 0;
+ int renderCount = 0;
  double timePassed = 0;
 
  @override
  void update(double dt) {
  super.update(dt);
  timePassed += dt;
+ updateCount++;
+ }
 
- callCount++;
+ @override
+ void render(Canvas canvas) {
+ super.render(canvas);
+ renderCount++;
  }
 }
 
@@ -86,7 +92,8 @@ void main() {
  // shouldn't run another frame on the game
  await tester.pump();
 
- expect(game.callCount, equals(2));
+ // Remember that there is one initial update(0) called.
+ expect(game.updateCount, equals(3));
  },
  );
 
@@ -105,7 +112,8 @@ void main() {
  game.resumeEngine();
  await tester.pump();
 
- expect(game.callCount, equals(3));
+ // Remember that there is one initial update(0) called.
+ expect(game.updateCount, equals(4));
  },
  );
 
@@ -121,7 +129,8 @@ void main() {
  await tester.tap(find.text('Toggle'));
  await tester.pumpAndSettle();
 
- expect(game.callCount, equals(2));
+ // Remember that there is one initial update(0) called.
+ expect(game.updateCount, equals(3));
  },
  );
 
@@ -132,7 +141,7 @@ void main() {
  await tester.pump();
  await tester.pump();
 
- expect(game.callCount, equals(0));
+ expect(game.updateCount, equals(0));
  },
  );
 
@@ -149,7 +158,7 @@ void main() {
  await tester.pump();
  await tester.pump();
 
- expect(game.callCount, equals(2));
+ expect(game.updateCount, equals(2));
  },
  );
 
@@ -173,7 +182,8 @@ void main() {
  await tester.pump(const Duration(seconds: 100));
  await tester.pump(frameLength);
 
- expect(game.callCount, equals(4));
+ // Remember that there is one initial update(0) after mount
+ expect(game.updateCount, equals(5));
  expect(game.timePassed, equals(3));
  },
  );