adding direction extension methods

packages/leap/lib/src/entities/status.dart

@@ -38,11 +38,12 @@ class EntityStatus extends Component {
 mixin IgnoredByWorld on EntityStatus {}
 
 /// A status mixin which indicates the parent entity should not
-/// be affected by gravity while the status is present.
+/// be affected by gravity while the status is present
+/// (via [GravityAccelerationBehavior]).
 mixin IgnoresGravity on EntityStatus {}
 
 /// A status mixin which indicates the parent entity should not
-/// be automatically moved by its velocity.
+/// be automatically moved by its velocity (via [ApplyVelocityBehavior])
 mixin IgnoresVelocity on EntityStatus {}
 
 /// A status mixin which indicates the parent entity should not

packages/leap/lib/src/utils/direction.dart

@@ -3,7 +3,27 @@ enum HorizontalDirection {
   right,
 }
 
+extension HorizontalDirectionExtension on HorizontalDirection {
+  HorizontalDirection flip() {
+    if (this == HorizontalDirection.left) {
+      return HorizontalDirection.right;
+    } else {
+      return HorizontalDirection.left;
+    }
+  }
+}
+
 enum VerticalDirection {
   up,
   down,
 }
+
+extension VerticalDirectionExtension on VerticalDirection {
+  VerticalDirection flip() {
+    if (this == VerticalDirection.up) {
+      return VerticalDirection.down;
+    } else {
+      return VerticalDirection.up;
+    }
+  }
+}