Adding example for spritesheet

doc/examples/spritesheet/.gitignore

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+# Miscellaneous
+*.class
+*.log
+*.pyc
+*.swp
+.DS_Store
+.atom/
+.buildlog/
+.history
+.svn/
+
+# IntelliJ related
+*.iml
+*.ipr
+*.iws
+.idea/
+
+# Visual Studio Code related
+.vscode/
+
+# Flutter/Dart/Pub related
+**/doc/api/
+.dart_tool/
+.flutter-plugins
+.packages
+.pub-cache/
+.pub/
+/build/
+
+# Android related
+**/android/**/gradle-wrapper.jar
+**/android/.gradle
+**/android/captures/
+**/android/gradlew
+**/android/gradlew.bat
+**/android/local.properties
+**/android/**/GeneratedPluginRegistrant.java
+
+# iOS/XCode related
+**/ios/**/*.mode1v3
+**/ios/**/*.mode2v3
+**/ios/**/*.moved-aside
+**/ios/**/*.pbxuser
+**/ios/**/*.perspectivev3
+**/ios/**/*sync/
+**/ios/**/.sconsign.dblite
+**/ios/**/.tags*
+**/ios/**/.vagrant/
+**/ios/**/DerivedData/
+**/ios/**/Icon?
+**/ios/**/Pods/
+**/ios/**/.symlinks/
+**/ios/**/profile
+**/ios/**/xcuserdata
+**/ios/.generated/
+**/ios/Flutter/App.framework
+**/ios/Flutter/Flutter.framework
+**/ios/Flutter/Generated.xcconfig
+**/ios/Flutter/app.flx
+**/ios/Flutter/app.zip
+**/ios/Flutter/flutter_assets/
+**/ios/ServiceDefinitions.json
+**/ios/Runner/GeneratedPluginRegistrant.*
+
+# Exceptions to above rules.
+!**/ios/**/default.mode1v3
+!**/ios/**/default.mode2v3
+!**/ios/**/default.pbxuser
+!**/ios/**/default.perspectivev3
+!/packages/flutter_tools/test/data/dart_dependencies_test/**/.packages

doc/examples/spritesheet/.metadata

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+# This file tracks properties of this Flutter project.
+# Used by Flutter tool to assess capabilities and perform upgrades etc.
+#
+# This file should be version controlled and should not be manually edited.
+
+version:
+  revision: 7fc14a55af64462763d28abfb4e610086c6e0f39
+  channel: dev
+
+project_type: app

doc/examples/spritesheet/README.md

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+# spritesheet
+
+A Flame game showcasing how to use spritesheet
+
+Image from: https://github.com/fireslime/bgug

doc/examples/spritesheet/lib/main.dart

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+import 'package:flame/flame.dart';
+import 'package:flame/game.dart';
+import 'package:flame/spritesheet.dart';
+import 'package:flame/components/animation_component.dart';
+import 'package:flame/components/component.dart';
+import 'package:flutter/material.dart';
+
+void main() async {
+  final Size size = await Flame.util.initialDimensions();
+  final game = MyGame(size);
+  runApp(game.widget);
+}
+
+class MyGame extends BaseGame {
+  MyGame(Size screenSize) {
+    size = screenSize;
+
+    final spritesheet = SpriteSheet(
+        imageName: 'spritesheet.png',
+        textureWidth: 16,
+        textureHeight: 18,
+        columns: 11,
+        rows: 2,
+    );
+
+    final vampireAnimation = spritesheet.createAnimation(0, stepTime: 0.1, to: 7);
+    final ghostAnimation = spritesheet.createAnimation(1, stepTime: 0.1, to: 7);
+
+    final vampireComponent = AnimationComponent(80, 90, vampireAnimation);
+    vampireComponent.x = 150;
+    vampireComponent.y = 100;
+
+    final ghostComponent = AnimationComponent(80, 90, ghostAnimation);
+    ghostComponent.x = 150;
+    ghostComponent.y = 220;
+
+    add(vampireComponent);
+    add(ghostComponent);
+
+    // Some plain sprites
+    final vampireSpriteComponent = SpriteComponent.fromSprite(80, 90, spritesheet.getSprite(0, 0));
+    vampireSpriteComponent.x = 50;
+    vampireSpriteComponent.y = 100;
+
+    final ghostSpriteComponent = SpriteComponent.fromSprite(80, 90, spritesheet.getSprite(1, 0));
+    ghostSpriteComponent.x = 50;
+    ghostSpriteComponent.y = 220;
+
+    add(vampireSpriteComponent);
+    add(ghostSpriteComponent);
+  }
+}

doc/examples/spritesheet/pubspec.yaml

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+name: spritesheet
+description: Flame sample game showcasing spritesheet features
+
+version: 1.0.0+1
+
+environment:
+  sdk: ">=2.1.0 <3.0.0"
+
+dependencies:
+  flutter:
+    sdk: flutter
+  flame:
+      path: ../../../
+
+dev_dependencies:
+  flutter_test:
+    sdk: flutter
+
+flutter:
+  assets:
+    - assets/images/spritesheet.png