How to adjust brush fade to a path automaticly?

[Ofnuts]

Not worth it... I really want the fade because I hope to be able to allow any kind of fade-related dynamics (size, opacity, color, direction..., and also following the fade curve defined in the dynamics). I even wonder if this could be made to work together with the "line" mode. As you can see, aiming for the maximum "wow" effect wit the minimum code