Mmm, looks like a combination of the waveform editor’s transient detection and the “slices to pattern” tool could handle this exact thing.
Transient detection:http://tutorials.renoise.com/wiki/Waveform#Slice_Markers
Slices to pattern:https://forum.renoise.com/t/new-tool-2-7-2-8-slices-to-pattern/31593
Okay, that seems sensible. Thanks! One other question : Slices to Pattern - Is there a Renoise 3.0 version?
Edit : Ok, 2.8 version works with 3.0 after conversion. and i was able to find the Pattern → Slices to pattern after looking at what dBlue said about where it would be…