Retraction length should vary with travel time

[JulienBernard3383279]

Is there an existing issue for this feature request?

• [X] I have searched the existing issues

Is your feature request related to a problem?

Filament retraction aims at preventing oozing, which happens in an amount roughly linear with the time spent travelling. So it stands to reason the filament retraction amount should also be linear with the travel time.

I think merely a threshold for whether to apply retraction and a unique retraction length often lead to painful situations with prints with both big travels (require high retraction) and short-medium sized features (such as text on side walls), as I've experienced in the past.

Which printers will be beneficial to this feature?

All

Describe the solution you'd like

One solution could be to configure both the min threshold for any retraction, the threshold for the max retraction, and the max retraction, and scale retractions linearly with travel distance below the threshold for max retraction.

Of course with time would be closer to perfection, but scaling with distance is probably significantly easier. I don't think implementing it for more complicated scenarios such as tool changes would be worth it if complicated, just travels within a print or between several prints already cover the cases I can think of where you wouldn't want max retraction; others can just default to that.

My thanks to anyone that tries implementing it.

Describe alternatives you've considered

No response

Additional context

No response