Automatic brush size for zoom level

There's an app called "Pixel Playground" for iOS, which has an extremely neat feature of automatically adapting the brush size to the current zoom level:

https://www.youtube.com/watch?v=vRRpJ8K6rvY

(in the video, you can see this adaptive behaviour with the greyed out pixel brush while zooming in).

Would be great to have this in PyxelEdit.