feat: Helpers for whether a PositionComponent is flipped. (#1700)

Helpers that just check if the scale is negative so that the user can now whether the component has been flipped.

packages/flame/lib/src/components/position_component.dart

@@ -349,6 +349,12 @@ class PositionComponent extends Component
     transform.flipVertically();
   }
 
+  /// Whether it is currently flipped horizontally.
+  bool get isFlippedHorizontally => transform.scale.x.isNegative;
+
+  /// Whether it is currently flipped vertically.
+  bool get isFlippedVertically => transform.scale.y.isNegative;
+
   //#endregion
 
   /// Internal handler that must be invoked whenever either the [size]

packages/flame/test/components/position_component_test.dart

@@ -465,6 +465,40 @@ void main() {
       expect(component.center, closeToVector(x, y, epsilon: 1e-14));
     });
 
+    test('isHorizontallyFlipped', () {
+      final component = PositionComponent()
+        ..size = Vector2(10, 10)
+        ..position = Vector2(50, 20)
+        ..anchor = const Anchor(0.6, 0.8);
+
+      expect(component.isFlippedHorizontally, isFalse);
+      component.flipHorizontally();
+      expect(component.isFlippedHorizontally, isTrue);
+      component.flipHorizontally();
+      expect(component.isFlippedHorizontally, isFalse);
+      component.flipHorizontallyAroundCenter();
+      expect(component.isFlippedHorizontally, isTrue);
+      component.flipHorizontallyAroundCenter();
+      expect(component.isFlippedHorizontally, isFalse);
+    });
+
+    test('isVerticallyFlipped', () {
+      final component = PositionComponent()
+        ..size = Vector2(10, 10)
+        ..position = Vector2(50, 20)
+        ..anchor = const Anchor(0.6, 0.8);
+
+      expect(component.isFlippedVertically, isFalse);
+      component.flipVertically();
+      expect(component.isFlippedVertically, isTrue);
+      component.flipVertically();
+      expect(component.isFlippedVertically, isFalse);
+      component.flipVerticallyAroundCenter();
+      expect(component.isFlippedVertically, isTrue);
+      component.flipVerticallyAroundCenter();
+      expect(component.isFlippedVertically, isFalse);
+    });
+
     test('rotations', () {
       final component = PositionComponent()
         ..size = Vector2(8, 6)