when drawing smooth controller events, that is, with raster disabled or
a small raster setting, then this is only very sluggish. the reason is
that muse still synchrounously inserts the controller events when
drawing: for every pixel drawn, muse tells the audio thread to add the
event and WAITS for it to finish, which takes some fractions of a
second. when you want to draw controllers faster than "dead slowly",
this doesn't work anymore.
so my proposal:
while drawing, NOT add the events, but cache the drawn stuff into some
local list instead. when the mouse is released then, put all the cache
content into one operation-group and use song->applyOperationGroup,
which is much faster.
do you see any potential problems there?