Sometime we need to use an inverse mask in flash ( like a normal mask but it was just inverse )
Here's an example of an inverse mask, We can achieve that using Blendmodes.
We will use ERASE blendmode to get a nice inverse mask effect. But there's another thing to be careful about!
Make sure the Outer clip ( holding your mask ) has a blendmode set to LAYER!
_Outerclip.blendMode = BlendMode.LAYER;
_inverseMask.blendMode = BlendMode.ERASE;