From 9828aba2a12f03fccbc1095bc8e4918ae58fa31b Mon Sep 17 00:00:00 2001
From: Jack Humbert <jack.humb@gmail.com>
Date: Thu, 21 Apr 2016 18:14:25 -0400
Subject: adds multiple voices and the ability to iterate/deiterate between
 them

---
 keyboard/preonic/keymaps/default/keymap.c | 21 +++++++++++++++++++--
 quantum/audio/voices.c                    | 31 +++++++++++++++++++++++++++++--
 quantum/audio/voices.h                    |  6 +++++-
 3 files changed, 53 insertions(+), 5 deletions(-)

diff --git a/keyboard/preonic/keymaps/default/keymap.c b/keyboard/preonic/keymaps/default/keymap.c
index 267bfab3d7..f0d5ed6030 100644
--- a/keyboard/preonic/keymaps/default/keymap.c
+++ b/keyboard/preonic/keymaps/default/keymap.c
@@ -3,7 +3,6 @@
 #include "eeconfig.h"
 #ifdef AUDIO_ENABLE
   #include "audio.h"
-  #include "song_list.h"
 #endif
 
 // Each layer gets a name for readability, which is then used in the keymap matrix below.
@@ -31,6 +30,8 @@
 #endif
 #define MUS_OFF M(8)
 #define MUS_ON M(9)
+#define VC_IN M(10)
+#define VC_DE M(11)
 
 // Fillers to make layering more clear
 #define _______ KC_TRNS
@@ -171,7 +172,7 @@ const uint16_t PROGMEM keymaps[][MATRIX_ROWS][MATRIX_COLS] = {
   {KC_F1,   KC_F2,   KC_F3,   KC_F4,   KC_F5,   KC_F6,   KC_F7,   KC_F8,   KC_F9,   KC_F10,  KC_F11,  KC_F12},
   {_______, RESET,   _______, _______, _______, _______, _______, _______, _______, _______, _______, KC_DEL},
   {_______, _______, _______, AUD_ON,  AUD_OFF, AG_NORM, AG_SWAP,  QWERTY, COLEMAK, DVORAK,  _______, _______},
-  {_______, _______, _______, MUS_ON,  MUS_OFF, _______, _______, _______, _______, _______, _______, _______},
+  {_______, VC_DE,   VC_IN,   MUS_ON,  MUS_OFF, _______, _______, _______, _______, _______, _______, _______},
   {_______, _______, _______, _______, _______, _______, _______, _______, _______, _______, _______, _______}
 }
 
@@ -289,6 +290,22 @@ const macro_t *action_get_macro(keyrecord_t *record, uint8_t id, uint8_t opt)
             #endif
           }
         break;
+        case 10:
+          if (record->event.pressed) {
+            #ifdef AUDIO_ENABLE
+              voice_iterate();
+              PLAY_NOTE_ARRAY(music_scale, false, 0);
+            #endif
+          }
+        break;
+        case 11:
+          if (record->event.pressed) {
+            #ifdef AUDIO_ENABLE
+              voice_deiterate();
+              PLAY_NOTE_ARRAY(music_scale, false, 0);
+            #endif
+          }
+        break;
       }
     return MACRO_NONE;
 };
diff --git a/quantum/audio/voices.c b/quantum/audio/voices.c
index 51652927bd..92ada47f7b 100644
--- a/quantum/audio/voices.c
+++ b/quantum/audio/voices.c
@@ -1,23 +1,35 @@
 #include "voices.h"
 
+// these are imported from audio.c
 extern uint16_t envelope_index;
 extern float note_timbre;
+extern float polyphony_rate;
 
-voice_type voice = default_voice;
+voice_type voice = duty_osc;
 
 void set_voice(voice_type v) {
     voice = v;
 }
 
+void voice_iterate() {
+    voice = (voice + 1) % number_of_voices;
+}
+
+void voice_deiterate() {
+    voice = (voice - 1) % number_of_voices;
+}
+
 float voice_envelope(float frequency) {
     // envelope_index ranges from 0 to 0xFFFF, which is preserved at 880.0 Hz
     uint16_t compensated_index = (uint16_t)((float)envelope_index * (880.0 / frequency));
 
     switch (voice) {
         case default_voice:
-            // nothing here on purpose
+            note_timbre = TIMBRE_50;
+            polyphony_rate = 0;
         break;
         case butts_fader:
+            polyphony_rate = 0;
             switch (compensated_index) {
                 case 0 ... 9:
                     frequency = frequency / 4;
@@ -36,6 +48,7 @@ float voice_envelope(float frequency) {
             }
         break;
         case octave_crunch:
+            polyphony_rate = 0;
             switch (compensated_index) {
                 case 0 ... 9:
                 case 20 ... 24:
@@ -54,6 +67,20 @@ float voice_envelope(float frequency) {
                 break;
             }
         break;
+        case duty_osc:
+            // This slows the loop down a substantial amount, so higher notes may freeze
+            polyphony_rate = 0;
+            switch (compensated_index) {
+                default:
+                    #define SPEED 10
+                    #define AMP   .75
+                    // sine wave is slow
+                    // note_timbre = (sin((float)compensated_index/10000*SPEED) * AMP / 2) + .5;
+                    // triangle wave is a bit faster
+                    note_timbre = (float)abs((compensated_index*SPEED % 3000) - 1500) * ( AMP / 1500 ) + (1 - AMP) / 2;
+                break;
+            }
+        break;
     }
 
     return frequency;
diff --git a/quantum/audio/voices.h b/quantum/audio/voices.h
index 317f5d98c5..44c5066b55 100644
--- a/quantum/audio/voices.h
+++ b/quantum/audio/voices.h
@@ -13,9 +13,13 @@ float voice_envelope(float frequency);
 typedef enum {
     default_voice,
     butts_fader,
-    octave_crunch
+    octave_crunch,
+    duty_osc,
+    number_of_voices // important that this is last
 } voice_type;
 
 void set_voice(voice_type v);
+void voice_iterate();
+void voice_deiterate();
 
 #endif
\ No newline at end of file
-- 
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