MIDI - optimise midi_clock_beat

Now no longer requires 24 messages to be sent per beat from Spider to Tau. Instead, just one message is sent with the number of ms for a beat. Tau then does the scheduling for 24 MIDI clock tick messages over the beat duration to be sent to sp_midi.

Author: samaaron

app/server/erlang/tau/src/tau_server/tau_server_midi.erl

@@ -148,6 +148,18 @@ midi_send(_Time, <<Data/binary>>) ->
     case tau_server_midi_out:encode_midi_from_osc(Data) of
         {ok, multi_chan, _, PortName, MIDIBinaries} ->
             [sp_midi:midi_send(PortName, MB) || MB <- MIDIBinaries];
+        {ok, clock_beat, PortName, BeatDurationMs, MIDIBinary} ->
+            %% Send a full MIDI beat's worth of clock tick messages.
+            %% This means 24 message each separated by TickIntervalMs.
+
+            TickIntervalMs = BeatDurationMs / 24.0,
+            lists:foreach(
+              fun(I) ->
+                      spawn(fun () ->
+                                    timer:sleep(round(I * TickIntervalMs)),
+                                    sp_midi:midi_send(PortName, MIDIBinary)
+                            end)
+              end, lists:seq(0, 23));
         {ok,  _, PortName, MIDIBinary} ->
             sp_midi:midi_send(PortName, MIDIBinary);
         {error, ErrStr} ->

app/server/erlang/tau/src/tau_server/tau_server_midi_out.erl

@@ -166,6 +166,10 @@ encode_midi_from_osc(<<Bin/binary>>) ->
             Data = encode(start),
             {ok, start, PortName, Data};
 
+        {cmd, ["/clock_beat", PortName, TickIntervalMs]} ->
+            Data = encode(clock),
+            {ok, clock_beat, PortName, TickIntervalMs, Data};
+
         {cmd, ["/stop", PortName]} ->
             Data = encode(stop),
             {ok, stop, PortName, Data};

app/server/ruby/lib/sonicpi/lang/midi.rb

@@ -1391,13 +1391,11 @@ def midi_clock_beat(*args)
           end
 
           ports.each do |p|
-            time_warp times do |i, el|
-              __midi_send_timed("/clock", p)
-            end
+            __midi_send_timed_param_2("/clock_beat", p, __get_beat_dur_in_ms)
+            __midi_message "midi_clock_beat port: #{port}"
           end
-
-          __midi_message "midi_clock_beat port: #{port}"
         else
+
           __midi_rest_message "midi_clock_beat port: #{port}"
         end
       end

app/server/ruby/lib/sonicpi/runtime.rb

@@ -165,6 +165,10 @@ def __change_spider_beat_and_time_by_beat_delta!(beat_delta)
       end
     end
 
+    def __get_beat_dur_in_ms
+      __get_spider_sleep_mul * 1000.0
+    end
+
     def __get_spider_time
       if __in_link_bpm_mode
         @tau_api.link_get_clock_time_at_beat(__get_spider_beat)