flame/doc/examples/animations/lib/main.dart

import 'package:flutter/gestures.dart';
import 'package:flame/flame.dart';
import 'package:flame/game.dart';
import 'package:flame/animation.dart' as flame_animation;
import 'package:flame/components/animation_component.dart';
import 'package:flutter/material.dart';

void main() async {
  WidgetsFlutterBinding.ensureInitialized();
  final Size size = await Flame.util.initialDimensions();
  final game = MyGame(size);
  runApp(game.widget);
}

class MyGame extends BaseGame {
  final animation = flame_animation.Animation.sequenced('chopper.png', 4,
      textureWidth: 48, textureHeight: 48, stepTime: 0.15, loop: true);

  void addAnimation(double x, double y) {
    const textureWidth = 291.0;
    const textureHeight = 178.0;
    final animationComponent = AnimationComponent.sequenced(
        291, 178, 'creature.png', 18,
        amountPerRow: 10,
        textureWidth: textureWidth,
        textureHeight: textureHeight,
        stepTime: 0.15,
        loop: true,
        destroyOnFinish: true);
    animationComponent.x = x - textureWidth / 2;
    animationComponent.y = y - textureHeight / 2;

    add(animationComponent);
  }

  @override
  void onTapDown(TapDownDetails evt) {
    addAnimation(evt.globalPosition.dx, evt.globalPosition.dy);
  }

  MyGame(Size screenSize) {
    size = screenSize;

    final animationComponent = AnimationComponent(100, 100, animation);
    animationComponent.x = size.width / 2 - 100;
    animationComponent.y = 100;

    final reversedAnimationComponent =
        AnimationComponent(100, 100, animation.reversed());
    reversedAnimationComponent.x = size.width / 2;
    reversedAnimationComponent.y = 100;

    add(animationComponent);
    add(reversedAnimationComponent);
  }
}