From 1ac38718b783ccca9f393f9f4f3df55bba8c103a Mon Sep 17 00:00:00 2001
From: Holger Wirtz <wirtz@parasitstudio.de>
Date: Mon, 11 Mar 2019 13:58:51 +0100
Subject: [PATCH] Adding function for checking, if sound  is produced. If not,
 shut down the voice.

---
 MicroDexed.ino | 14 +++++++++++---
 config.h       |  3 ++-
 dexed.cpp      | 47 ++++++++++++++++++++++++++++++++++++++++++++++-
 dexed.h        |  2 ++
 4 files changed, 61 insertions(+), 5 deletions(-)

diff --git a/MicroDexed.ino b/MicroDexed.ino
index aebf63e..d68d092 100644
--- a/MicroDexed.ino
+++ b/MicroDexed.ino
@@ -123,6 +123,7 @@ uint8_t effect_delay_feedback = 0;
 uint8_t effect_delay_volume = 0;
 bool effect_delay_sync = 0;
 elapsedMicros fill_audio_buffer;
+elapsedMillis control_rate;
 
 #ifdef SHOW_CPU_LOAD_MSEC
 elapsedMillis cpu_mem_millis;
@@ -335,6 +336,13 @@ void loop()
   // MIDI input handling
   check_midi_devices();
 
+  // Shutdown unused voices
+  if (control_rate > CONTROL_RATE_MS)
+  {
+    control_rate = 0;
+    uint8_t shutdown_voices = dexed->getNumNotesPlaying();
+  }
+
 #ifdef I2C_DISPLAY
   // UI
   if (master_timer >= TIMER_UI_HANDLING_MS)
@@ -355,7 +363,7 @@ void loop()
 }
 
 /******************************************************************************
- * MIDI MESSAGE HANDLER
+   MIDI MESSAGE HANDLER
  ******************************************************************************/
 void handleNoteOn(byte inChannel, byte inNumber, byte inVelocity)
 {
@@ -654,9 +662,9 @@ void handleSystemReset(void)
 }
 
 /******************************************************************************
- * END OF MIDI MESSAGE HANDLER
+   END OF MIDI MESSAGE HANDLER
  ******************************************************************************/
- 
+
 bool checkMidiChannel(byte inChannel)
 {
   // check for MIDI channel
diff --git a/config.h b/config.h
index 77d4b90..6d2d771 100644
--- a/config.h
+++ b/config.h
@@ -60,7 +60,8 @@
 //* DEXED AND EFECTS SETTINGS
 //*************************************************************************************************
 #define DEXED_ENGINE DEXED_ENGINE_MODERN // DEXED_ENGINE_MARKI // DEXED_ENGINE_OPL
-
+#define CONTROL_RATE_MS 200
+ 
 // EFFECTS
 #define FILTER_MAX_FREQ 10000
 
diff --git a/dexed.cpp b/dexed.cpp
index 8a0a99e..33b3eee 100644
--- a/dexed.cpp
+++ b/dexed.cpp
@@ -63,7 +63,7 @@ Dexed::Dexed(int rate)
     voices[i].live = false;
   }
 
-  max_notes = 16;
+  max_notes = MAX_NOTES;
   currentNote = 0;
   resetControllers();
   controllers.masterTune = 0;
@@ -391,6 +391,51 @@ uint8_t Dexed::getMaxNotes(void)
   return max_notes;
 }
 
+uint8_t Dexed::getNumNotesPlaying(void)
+{
+  uint8_t op_carrier = controllers.core->get_carrier_operators(data[134]); // look for carriers
+  uint8_t i;
+  
+  for (i = 0; i < max_notes; i++)
+  {
+    if (voices[i].live == true)
+    {
+      uint8_t op_amp = 0;
+      uint8_t op_carrier_num = 0;
+
+      memset(&voiceStatus, 0, sizeof(VoiceStatus));
+
+      voices[i].dx7_note->peekVoiceStatus(voiceStatus);
+
+      for (uint8_t op = 0; op < 6; op++)
+      {
+        uint8_t op_bit = static_cast<uint8_t>(pow(2, op));
+
+        if ((op_carrier & op_bit) > 0)
+        {
+          {
+            // this voice is a carrier!
+            op_carrier_num++;
+
+            if (voiceStatus.amp[op] <= 1069 && voiceStatus.ampStep[op] == 4) // this voice produces no audio output
+              op_amp++;
+          }
+        }
+        if (op_amp == op_carrier_num)
+        {
+          // all carrier-operators are silent -> disable the voice
+          voices[i].live = false;
+          voices[i].sustained = false;
+          voices[i].keydown = false;
+          Serial.print("Voice shutdown [");
+          Serial.print(i,DEC);
+          Serial.println(F("]"));
+        }
+      }
+    }
+  }
+}
+
 bool Dexed::loadSysexVoice(uint8_t* new_data)
 {
   uint8_t* p_data = data;
diff --git a/dexed.h b/dexed.h
index 02a7383..de22102 100644
--- a/dexed.h
+++ b/dexed.h
@@ -160,6 +160,7 @@ class Dexed
     void keydown(uint8_t pitch, uint8_t velo);
     void setSustain(bool sustain);
     bool getSustain(void);
+    uint8_t getNumNotesPlaying(void);
 
     ProcessorVoice voices[MAX_NOTES];
     Controllers controllers;
@@ -190,6 +191,7 @@ class Dexed
     bool monoMode;
     bool refreshVoice;
     uint8_t engineType;
+    VoiceStatus voiceStatus;
     Lfo lfo;
     FmCore* engineMsfa;
     EngineMkI* engineMkI;