Fix hitbox circle on flip (#1165)

examples/lib/stories/collision_detection/circles_example.dart

@@ -39,13 +39,12 @@ class MyCollidable extends PositionComponent
           position: position,
           size: Vector2.all(100),
           anchor: Anchor.center,
-        ) {
-    addHitbox(HitboxCircle());
-  }
+        );
 
   @override
   Future<void> onLoad() async {
     await super.onLoad();
+    addHitbox(HitboxCircle());
     final center = gameRef.size / 2;
     velocity = (center - position)..scaleTo(150);
   }

packages/flame/CHANGELOG.md

@@ -10,6 +10,7 @@
  - Fix `Parallax.load` with different loading times
  - Fix render order of components and add tests
  - `isHud` renamed to `respectCamera`
+ - Fix `HitboxCircle` when component is flipped
 
 ## [1.0.0-releasecandidate.18]
  - Forcing portrait and landscape mode is now supported on web

packages/flame/lib/src/geometry/circle.dart

@@ -43,7 +43,8 @@ class Circle extends Shape {
     _scaledSize
       ..setFrom(size)
       ..multiply(scale);
-    return (min(_scaledSize.x, _scaledSize.y) / 2) * normalizedRadius;
+    return (min(_scaledSize.x.abs(), _scaledSize.y.abs()) / 2) *
+        normalizedRadius;
   }
 
   /// This render method doesn't rotate the canvas according to angle since a