Number of columns or drawing channels to split into.
Returns
void
Remarks
Use to split render into layers. By switching channels to can render
out-of-order (e.g. submit FG primitives before BG primitives)
Use to minimize draw calls (e.g. if going back-and-forth between multiple
clipping rectangles, prefer to append into separate channels then merge at
the end)
This API shouldn't have been in ImDrawList in the first place! Prefer using
your own persistent instance of ImDrawListSplitter as you can stack them.
The ImGui.ImDrawList_Channels* helpers cannot nest one split inside
another.
Split the draw list into independently ordered channels.