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livetrax/scripts/s_fader_automation.lua

57 lines
1.5 KiB
Lua

ardour { ["type"] = "Snippet", name = "fader automation" }
function factory () return function ()
local playhead = Session:transport_frame ()
local samplerate = Session:nominal_frame_rate ()
-- get selected tracks
rl = Editor:get_selection().tracks:routelist()
-- prepare undo operation
Session:begin_reversible_command ("Fancy Fade Out")
local add_undo = false -- keep track if something has changed
-- iterate over selected tracks
for r in rl:iter() do
local ac = r:amp():gain_control() -- ARDOUR:AutomationControl
local acl = ac:alist() -- ARDOUR:AutomationControlList (state, high-level)
local cl = acl:list() -- Evoral:ControlList (actual events)
ac:set_automation_state(ARDOUR.AutoState.Touch)
if cl:isnil() then
goto out
end
-- query the value at the playhead position
local g = cl:eval(playhead)
-- get state for undo
local before = acl:get_state()
-- delete all events after the playhead...
cl:truncate_end (playhead)
-- ...and generate some new ones.
for i=0,50 do
cl:add (playhead + i * samplerate / 50,
g * (1 - math.sqrt (i / 50)),
false, true)
end
-- remove dense events
cl:thin(20)
-- save undo
local after = acl:get_state()
Session:add_command (acl:memento_command(before, after))
add_undo = true
::out::
end
-- all done, commit the combined Undo Operation
if add_undo then
-- the 'nil' Commend here mean to use the collected diffs added above
Session:commit_reversible_command (nil)
else
Session:abort_reversible_command ()
end
end end