Inverting Graphics / drawRect alpha

[ZoorSteelchest]

Hi!

 

I have a Problem with a Graphics object.

I want to use it as Mask for a Sprite(the Sprite is just a straight Line).

 

The Dimensions of the Graphics Object are calculated by a few other Sprites, which may change. So the Mask also changes.

 

The Problem:

I can calculate the "visible" part, but not the invisible Part.

So I need something like the opposite of mask, like this here:  https://github.com/GoodBoyDigital/pixi.js/issues/252

 

A few things I have thought about:

-Drawing alpha on a fullsize graphics object ==> Not possible

-Inverting the Visible => Invisible and the Invisible => Visible Part ==> Not possible

-The Solution described at the issue ==> Dirty Hack

 

Anyone had the same Problem & solved it? :/

 

Thanks!