Support for "soft" brushes

[agruchala]

Is there a possibility to get support for soft brushes? (progressive opacity, solid inside, more clear on edges). I tried to do it with a combination of context.setShadow(...) and multiple drawings of the same path, but this is not perfect. I couldn't do it via "stroking" bitmap, tried everything really.

[LinusGeffarth]

I'm just maintainer of the project and don't really know a lot about CoreGraphics so I don't know how to develop that either. If you find a solution, feel free to open a PR!