I also would like to know the character position for each wrapped line in a paragraph also (and binding won't cover my use case).
My use case is that I've created a minimap replacement for the traditional scrollbar. I create the minimap display using runmode and an overlay which you can drag up/down. This works OK if your representation of the editor doesn't have wrapped lines.
However, if the editor does have wrapped lines, trying to do that in a runmode created representation for display in the minimap is near impossible as chars render differently at the large and small sizes, so wrap at different points and you end up with a mismatch.
If I knew where the line wraps happened in the editor, I could make the minimap not really have line wrapping and fake it by breaking lines at the correct positions.
Is there a way to get the wrap ch positions for each line wrapped?