Add Lua binding to query plugin-presets and scalepoints

share/scripts/s_pluginutils.lua

@@ -7,7 +7,7 @@ function factory () return function ()
 	for p in ARDOUR.LuaAPI.list_plugins():iter() do
 		print (p.name, p.unique_id, p.type)
 		local psets = p:get_presets()
-		if not empty:empty() then
+		if not psets:empty() then
 			for pset in psets:iter() do
 				print (" - ", pset.label)
 			end
@@ -25,19 +25,36 @@ function factory () return function ()
 		end
 	end
 
-
 	-------------------------------------------------------------------------------
 	-- load a plugin preset
-	route = Session:get_remote_nth_route(2)
+	local route = Session:get_remote_nth_route(2)
 	assert (route)
 	-- to 4th plugin (from top), ardour starts counting at zero
-	plugin = route:nth_plugin(3):to_insert():plugin(0)
+	local plugin = route:nth_plugin(3):to_insert():plugin(0)
 	assert (not plugin:isnil())
-	ps = plugin:preset_by_label("cutbass") -- get preset by name
-	assert (ps)
-	print (ps.uri)
-	plugin:load_preset (ps)
+	local ps = plugin:preset_by_label("cutbass") -- get preset by name
+	if ps and ps.valid then
+		print (ps.uri)
+		plugin:load_preset (ps)
+	end
 
+	-- query preset
+	local lp = plugin:last_preset ()
+	print ("valid?", lp.valid, "Preset ID:", lp.uri, "Preset Name:", lp.label, "User Preset (not factory):", lp.user)
+
+	-- list preset of given plugin
+	if not psets:empty() then
+		for pset in psets:iter() do
+			print (" - ", pset.label, pset.uri)
+		end
+	end
+
+	-- print scale-points of a given plugin-parameter
+	local _, pd = plugin:get_parameter_descriptor (3, ARDOUR.ParameterDescriptor())
+	local sp = ARDOUR.LuaAPI.desc_scale_points (pd[2]);
+	for k, v in pairs(sp) do
+		print (k, v)
+	end
 
 	-------------------------------------------------------------------------------
 	-- add a LuaProcessor (here "Scope") to all tracks