Touching through irregular shaped Sprite Objects

I have sprite obstacles in different shapes and sizes covering some other sprite objects in screen

For example clouds covering a factory, how can I implement some kind of click/ touch mask so that the touch to the factory is ignored when the white part of the cloud is touched?

The simplest method would be to use the is overlapping condition.

On touched factory

->cound is overlapping factory(inverted), do foo

The simplest method would be to use the is overlapping condition.

On touched factory

->cound is overlapping factory(inverted), do foo

Thanks, is the overlapping check determined by the bounding box of the sprite or the collision mask?

Polygon if its a Sprite.