add polyphony

README.md

@@ -0,0 +1,5 @@
+# wavetablet
+
+This is mostly just a little wrapper around paul's teensy audio library synth_wavetable, updated to make sure it runs on the ATSAMD51 with adafruit's atsamd fork of Audio.
+
+the `decoder.py` here is taken the teensy AudioSynthWaveform repo, with changes to make it output parsed soundfonts in the format expressed in the `synth_wavetable.cpp` file from the Audio repo

src/main.cc

@@ -1,23 +1,37 @@
 #include <Arduino.h>
-#include <SPI.h>
-#include <Wire.h>
-#include <AudioStream.h>
 #include <Audio.h>
+#include <AudioStream.h>
+#include <SPI.h>
 #include <USB-MIDI.h>
+#include <Wire.h>
 #include <synth_wavetable.h>
-#include <AnalogSaw_samples.h>
-#include <Flute_100kbyte_samples.h>
+
+// #include <AnalogSaw_samples.h>
+// #include <Flute_100kbyte_samples.h>
 #include <lead_samples.h>
+auto instrument = lead;
 
 // Audio mixers can take 4 inputs
 // Let's have 8 inputs in total for an 8-finger polyphonic synth
 AudioMixer4 left_hand;
 AudioMixer4 right_hand;
 
-AudioSynthWavetable synth1;
-AudioSynthKarplusStrong string1;
-AudioConnection patch1(synth1, 0, left_hand, 0);
-AudioConnection patch2(string1, 0, left_hand, 1);
+const int len_voices = 4 * 2;
+
+AudioSynthWavetable wavetable0, wavetable1, wavetable2, wavetable3, wavetable4,
+    wavetable5, wavetable6, wavetable7;
+AudioSynthWavetable *wavetables[]{&wavetable0, &wavetable1, &wavetable2,
+                                  &wavetable3, &wavetable4, &wavetable5,
+                                  &wavetable6, &wavetable7};
+
+AudioConnection tl0(wavetable0, 0, left_hand, 0);
+AudioConnection tl1(wavetable1, 0, left_hand, 1);
+AudioConnection tl2(wavetable2, 0, left_hand, 2);
+AudioConnection tl3(wavetable3, 0, left_hand, 3);
+AudioConnection tr4(wavetable4, 0, right_hand, 0);
+AudioConnection tr5(wavetable5, 0, right_hand, 1);
+AudioConnection tr6(wavetable6, 0, right_hand, 2);
+AudioConnection tr7(wavetable7, 0, right_hand, 3);
 
 // mixers can take mixers as inputs, so let's create another to be sent to both
 // speakers. pc2064v1 will be a polyphonic synth with monophonic output
@@ -33,27 +47,75 @@ AudioConnection patch_right_ear(mixer, 0, audioOut, 1);
 // some day to replace this with tinyusb again
 USBMIDI_CREATE_DEFAULT_INSTANCE();
 
+class Voice {
+public:
+  int id;
+  byte note;
+  int age;
+};
+
+Voice voices[len_voices];
+
+int age = 0;
+
+void play(Voice *voice, byte note, byte velocity) {
+    auto wt = wavetables[voice->id];
+  voice->note = note;
+  voice->age = age++;
+  wt->playNote(voice->note, velocity);
+}
+
 void noteOn(byte channel, byte note, byte velocity) {
-  Serial.printf("c: %d, note: %d, v: %d", channel, note, velocity);
-  AudioNoInterrupts();
-  synth1.playNote(note, 100);
-  // string1.noteOn(synth1.noteToFreq(note), 0.9);
-  AudioInterrupts();
+  int oldest_age = infinity();
+  int oldest_index = 0;
+
+  // get a free one
+  for (int i = 0; i < len_voices; i++) {
+    if (wavetables[i]->getEnvState() ==
+        AudioSynthWavetable::envelopeStateEnum::STATE_IDLE) {
+      return play(&voices[i], note, velocity);
+    }
+
+    // ok, a releasing one then
+    if (wavetables[i]->getEnvState() ==
+        AudioSynthWavetable::envelopeStateEnum::STATE_RELEASE) {
+      return play(&voices[i], note, velocity);
+    }
+
+    // or the eldest
+    if (voices[i].age < oldest_age) {
+      oldest_index = i;
+      oldest_age = voices[i].age;
+    }
+  }
+
+  play(&voices[oldest_index], note, velocity);
 }
 
 void noteOff(byte channel, byte note, byte velocity) {
-  Serial.printf("c: %d, note: %d, v: %d", channel, note, velocity);
-  synth1.stop(); 
+  bool nothing = true;
+  for (int i = 0; i < len_voices; i++) {
+    if (wavetables[i]->getEnvState()) {
+      nothing = false;
+    }
+    if (voices[i].note == note) {
+      wavetables[i]->stop();
+    }
+  }
+  if (nothing) {
+    age = 0;
+  }
 }
 
 void setup() {
-  synth1.setInstrument(lead);
-  synth1.amplitude(1);
-  Serial.println("hello, jerg");
-  left_hand.gain(0, 1.0);
-  right_hand.gain(0, 1.0);
-  mixer.gain(0, 0.5);
-  mixer.gain(1, 0.5);
+  for (int i = 0; i < len_voices; i++) {
+    voices[i].id = i;
+    wavetables[i]->setInstrument(instrument);
+    wavetables[i]->amplitude(1);
+  }
+
+  mixer.gain(0, 0.01);
+  mixer.gain(1, 0.01);
   AudioMemory(22);
   AudioProcessorUsageMaxReset();
   AudioMemoryUsageMaxReset();
@@ -62,6 +124,4 @@ void setup() {
   MIDI.setHandleNoteOff(noteOff);
 }
 
-void loop() {
-  MIDI.read();
-}
+void loop() { MIDI.read(); }