refactor: made MapBounds immutable (#144)

* refactor: made MapBounds immutable

* refactor: remove redundant import

packages/trashy_road/lib/game_settings.dart

@@ -1,10 +1,9 @@
-import 'dart:typed_data';
-
 import 'package:flame/components.dart';
+import 'package:trashy_road/src/game/game.dart';
 
 abstract class GameSettings {
   /// The dimensions of the grid.
-  static final Vector2 gridDimensions = _ImmutableVector2(128, 64);
+  static final Vector2 gridDimensions = UnmodifiableVector2View(128, 64);
 }
 
 extension TrashyRoadVector on Vector2 {
@@ -25,10 +24,3 @@ extension TrashyRoadVector on Vector2 {
   /// Modifications are made to the object.
   void toGameSize() => multiply(GameSettings.gridDimensions);
 }
-
-class _ImmutableVector2 extends Vector2 {
-  _ImmutableVector2(double x, double y)
-      : super.fromFloat64List(
-          UnmodifiableFloat64ListView(Float64List.fromList([x, y])),
-        );
-}

packages/trashy_road/lib/src/game/components/trashy_road_world/trashy_road_world.dart

@@ -4,7 +4,6 @@ import 'package:flame/components.dart';
 import 'package:flame_tiled/flame_tiled.dart';
 import 'package:trashy_road/src/game/entities/barrel/barrel.dart';
 import 'package:trashy_road/src/game/game.dart';
-import 'package:trashy_road/src/game/model/map_bounds.dart';
 
 /// The different layers in the Tiled map.
 enum _TiledLayer {
@@ -47,7 +46,12 @@ class TrashyRoadWorld extends Component {
         tiled.tileMap.getObjectGroup(_TiledLayer.borderLayer.name);
     tiled.addAll(borderLayer.objects.map(MapEdge.fromTiledObject));
 
-    bounds = MapBounds(tiled.topLeftPosition, tiled.bottomLeftPosition);
+    bounds = MapBounds.fromLTWH(
+      tiled.topLeftPosition.x,
+      tiled.topLeftPosition.y,
+      tiled.width,
+      tiled.height,
+    );
   }
 
   final TiledComponent tiled;
@@ -74,7 +78,3 @@ extension on RenderableTiledMap {
     return objectGroup;
   }
 }
-
-extension on TiledComponent {
-  Vector2 get bottomLeftPosition => topLeftPosition + Vector2(width, height);
-}

packages/trashy_road/lib/src/game/game.dart

@@ -16,6 +16,7 @@ export 'bloc/game_bloc.dart';
 export 'components/components.dart';
 export 'debug_game.dart';
 export 'entities/entities.dart';
+export 'models/models.dart';
 export 'view/view.dart';
 export 'widgets/widgets.dart';
 

packages/trashy_road/lib/src/game/models/map_bounds.dart

@@ -0,0 +1,26 @@
+import 'package:flame/components.dart';
+import 'package:meta/meta.dart';
+import 'package:trashy_road/src/game/models/models.dart';
+
+@immutable
+class MapBounds {
+  const MapBounds._(this.topLeft, this.bottomRight);
+
+  /// Creates a [MapBounds] from the left, top, width and height.
+  ///
+  /// Similar to `Rect.fromLTWH` from `dart:ui`.
+  factory MapBounds.fromLTWH(double x, double y, double width, double height) {
+    final topLeft = UnmodifiableVector2View(x, y);
+    final bottomRight = UnmodifiableVector2View(x + width, y + height);
+    return MapBounds._(topLeft, bottomRight);
+  }
+
+  final UnmodifiableVector2View topLeft;
+  final UnmodifiableVector2View bottomRight;
+
+  bool isPointInside(Vector2 position) =>
+      position.x >= topLeft.x &&
+      position.x <= bottomRight.x &&
+      position.y <= bottomRight.y &&
+      position.y >= topLeft.y;
+}

packages/trashy_road/lib/src/game/models/models.dart

@@ -0,0 +1,2 @@
+export 'map_bounds.dart';
+export 'unmodifiable_vector2.dart';

packages/trashy_road/lib/src/game/models/unmodifiable_vector2.dart

@@ -0,0 +1,10 @@
+import 'dart:typed_data';
+
+import 'package:flame/components.dart' show Vector2;
+
+class UnmodifiableVector2View extends Vector2 {
+  UnmodifiableVector2View(double x, double y)
+      : super.fromFloat64List(
+          UnmodifiableFloat64ListView(Float64List.fromList([x, y])),
+        );
+}