Add cc_limit option (#19)

* Add cc_limit option

* Add some documentation

* CR fix

README.md

@@ -42,6 +42,7 @@ passthrough assigns some midi routing settings for each connected midi device in
 - `Quantize midi` wraps note data to scales (quantization is set per connected midi device, so different scales can be used if desired)
 - `Root` sets the root note of the current scale
 - `Scale` sets the scale type (Major, Minor.. )
+- `CC limit` sets the limit of midi CC messages to be sent for every channel per `25ms` timeframe. if more messages than this limit are received, then the last messages (per channel) will be sent automatically on next timeframe. this is useful when a midi controller is generating too many messages too fast (eg. moving all the faders at once on a novation launchcontrol xl). the `Pass all` option allows all CC messages to passthrough, without any kind of limiting. the `Pass none` option doesn't allow any midi CC messages to passthrough, effectively removing all of them
 
 additionally, `Midi panic` is a toggle to stop all active notes if some notes are hanging.
 

lib/core.lua

@@ -7,7 +7,11 @@ pt.input_channels = {"No change"}
 pt.output_channels = {"Device src."}
 pt.toggles = {"no", "yes"}
 pt.scales = {}
+pt.cc_limits = {"Pass all", "Pass none"}
+for i = 1, 10 do table.insert(pt.cc_limits, i) end
 local active_notes = {}
+local cc_limit_count = {}
+local cc_limit_init = {}
 
 -- TODO: this is a mess and needs refactoring
 id_port_lookup = {} -- used to lookup midi port by id
@@ -42,6 +46,37 @@ pt.build_scale = function(root, scale, index)
     pt.scales[index] = MusicUtil.generate_scale_of_length(root, scale, 128)
 end
 
+-- CC LIMIT --
+local function cc_limit_send(msg, target, out_ch, cc_limit)
+    if cc_limit == 2 then
+        return
+    end
+
+    if cc_limit == 1 then
+        target:cc(msg.cc, msg.val, out_ch)
+
+        return
+    end
+
+    if cc_limit_count[target] == nil then
+        cc_limit_count[target] = 0
+    end
+
+    if cc_limit_count[target] < cc_limit - 2 then
+        target:cc(msg.cc, msg.val, out_ch)
+        cc_limit_count[target] = cc_limit_count[target] + 1
+    else
+        if cc_limit_init[target] == nil then
+          cc_limit_init[target] = {}
+        end
+        if cc_limit_init[target][out_ch] == nil then
+            cc_limit_init[target][out_ch] = {}
+        end
+
+        cc_limit_init[target][out_ch][msg.cc] = msg.val
+    end
+end
+
 -- MIDI DEVICE DETECTION --
 for i = 1, 16 do
     table.insert(pt.input_channels, i)
@@ -110,6 +145,8 @@ pt.setup_midi = function()
     id_port_lookup = id_port_map
 
     pt.targets = targets
+
+    metro.init(pt.handle_cc_limit, 0.025):start()
 end
 
 pt.root_note_formatter = MusicUtil.note_num_to_name
@@ -143,7 +180,7 @@ pt.stop_all_notes = function()
 end
 
 -- DATA HANDLERS --
-pt.handle_midi_data = function(msg, target, out_ch, quantize_midi, current_scale)
+pt.handle_midi_data = function(msg, target, out_ch, quantize_midi, current_scale, cc_limit)
     local note = msg.note
 
     if note ~= nil then
@@ -167,7 +204,7 @@ pt.handle_midi_data = function(msg, target, out_ch, quantize_midi, current_scale
     elseif msg.type == "program_change" then
         target:program_change(msg.val, out_ch)
     elseif msg.type == "cc" then
-        target:cc(msg.cc, msg.val, out_ch)
+        cc_limit_send(msg, target, out_ch, cc_limit)
     end
 end
 
@@ -183,7 +220,20 @@ pt.handle_clock_data = function(msg, target)
     end
 end
 
-pt.device_event = function(origin, device_target, input_channel, output_channel, send_clock, quantize_midi, current_scale, data)
+pt.handle_cc_limit = function()
+  for target, v in pairs(cc_limit_init) do
+    for out_ch, ccs in pairs(v) do
+      for cc, value in pairs(ccs) do
+        target:cc(cc, value, out_ch)
+      end
+    end
+  end
+
+  cc_limit_count = {}
+  cc_limit_init = {}
+end
+
+pt.device_event = function(origin, device_target, input_channel, output_channel, send_clock, quantize_midi, current_scale, cc_limit, data)
     if #data == 0 then
         print("no data")
         return
@@ -202,7 +252,7 @@ pt.device_event = function(origin, device_target, input_channel, output_channel,
         local scale = pt.scales[origin]
 
         for k, v in pairs(connections) do
-          pt.handle_midi_data(msg, v, out_ch, quantize_midi, scale)
+          pt.handle_midi_data(msg, v, out_ch, quantize_midi, scale, cc_limit)
         end
     end
 

lib/mod.lua

@@ -49,7 +49,8 @@ function write_state()
     io.write("send_clock="..v.send_clock..",")
     io.write("quantize_midi="..v.quantize_midi..",")
     io.write("current_scale="..v.current_scale..",")
-    io.write("root_note="..v.root_note.."}")
+    io.write("root_note="..v.root_note..",")
+    io.write("cc_limit="..v.cc_limit.."}")
   end
   io.write("}\n")
   io.close(f)
@@ -63,6 +64,10 @@ function read_state()
   end
 
   for i = 1, tab.count(state) do
+    if state[i].cc_limit == nil then
+      state[i].cc_limit = 1
+    end
+
     core.build_scale(state[i].root_note, state[i].current_scale, state[i].dev_port)
   end
 end
@@ -116,7 +121,8 @@ function create_config()
         send_clock = 1,
         quantize_midi = 1,
         current_scale = 1,
-        root_note = 0
+        root_note = 0,
+        cc_limit = 1
       }
     else
       state[v.port].dev_port = v.port
@@ -195,7 +201,13 @@ function create_config()
           action = function()
             core.build_scale(state[k].root_note, state[k].current_scale, k)
           end
-        }
+        },
+      cc_limit = {
+        param_type = "option",
+        id = "cc_limit",
+        name = "CC limit",
+        options = core.cc_limits
+      }
     }
 
     config[k].target.action(state[k].target)
@@ -220,6 +232,7 @@ function device_event(id, data)
         port_config.send_clock,
         port_config.quantize_midi,
         port_config.current_scale,
+        port_config.cc_limit,
         data)
 
       api.user_event(id, data)
@@ -277,7 +290,7 @@ local get_menu_pagination_table = function()
 end
 
 -- MOD MENU --
-local screen_order = {"active", "target", "input_channel", "output_channel", "send_clock", "quantize_midi", "root_note", "current_scale", "midi_panic"}
+local screen_order = {"active", "target", "input_channel", "output_channel", "send_clock", "quantize_midi", "root_note", "current_scale", "cc_limit", "midi_panic"}
 local m = {
   list=screen_order,
   pos=0,

lib/passthrough.lua

@@ -29,6 +29,7 @@ local function device_event(id, data)
       params:get("send_clock_"..port)==2,
       params:get("quantize_midi_"..port),
       params:get("current_scale_"..port),
+      params:get("cc_limit_"..port),
       data)
 
     Passthrough.user_event(id, data)
@@ -48,7 +49,7 @@ function Passthrough.init()
   if core.has_devices == true then
 
       port_amount = tab.count(core.ports)
-      params:add_group("PASSTHROUGH", 9*port_amount + 2)
+      params:add_group("PASSTHROUGH", 10*port_amount + 2)
 
       for k, v in pairs(core.ports) do
           params:add_separator(v.port .. ': ' .. v.name)
@@ -134,7 +135,12 @@ function Passthrough.init()
                 core.build_scale(params:get("root_note_"..v.port), params:get("current_scale_"..v.port), v.port)
               end
             }
-
+          params:add {
+            type = "option",
+            id = "cc_limit_"..v.port,
+            name = "CC limit",
+            options = core.cc_limits
+          }
           end
           params:add_separator("All devices")
           params:add {