I have been using renoise for a while and tried to look for this “feature”, but not found where it’s located – perhaps its not even present? I would like to change the “Loop-points” in the sampler-window in the song. Reason is that A: this is a popular effect and B: reason A is driving me crazy due to clients request(s).
EDIT: explanation, as if you would pick up one of the loop-points and “drag” them in one direction while playing the sample.
You just grab the little tab that say S or E and move it. (S is at the top, E at the bottom, Start, End.) It will Snap to whatever is set for selection snapping top right area of the edit window. There is a fine editor if you need more precision and are not happy just using Zero Crossing snap.