some more example lua scripts

scripts/s_plugin_automation.lua

@@ -0,0 +1,35 @@
+ardour { ["type"] = "Snippet", name = "plugin automation2" }
+
+function factory () return function ()
+	local playhead = Session:transport_frame ()
+	local samplerate = Session:nominal_frame_rate ()
+
+	local r = Session:route_by_remote_id(3)
+	-- get AutomationControList, ControlList and ParameterDescriptor
+	local acl, cl, pd = ARDOUR.LuaAPI.plugin_automation (r:nth_plugin (0), 0)
+
+	if not acl:isnil() then
+		print ("Parameter Range", pd.lower, pd.upper)
+		print ("Current value", cl:eval(playhead))
+
+		-- prepare undo operation
+		Session:begin_reversible_command ("Automatix")
+		local before = acl:get_state()
+
+		-- remove future automation
+		cl:truncate_end (playhead)
+
+		-- add new data points after the playhead 1 sec min..max
+		-- without guard-points, but with initial (..., false, true)
+		for i=0,10 do
+			cl:add (playhead + i * samplerate / 10,
+				 pd.lower + math.sqrt (i / 10) * (pd.upper - pd.lower),
+				 false, true)
+		end
+
+		-- save undo
+		local after = acl:get_state()
+		Session:add_command (acl:memento_command(before, after))
+		Session:commit_reversible_command (nil)
+	end
+end end