1 files changed, 165 insertions, 0 deletions

diff --git a/quantum/audio/voices.c b/quantum/audio/voices.c
new file mode 100644
index 000000000..6d4172a06
--- /dev/null
+++ b/quantum/audio/voices.c
@@ -0,0 +1,165 @@
+#include "voices.h"
+#include "audio.h"
+#include "stdlib.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;
+
+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:
+            note_timbre = TIMBRE_50;
+            polyphony_rate = 0;
+                break;
+
+        case butts_fader:
+            polyphony_rate = 0;
+            switch (compensated_index) {
+                case 0 ... 9:
+                    frequency = frequency / 4;
+                    note_timbre = TIMBRE_12;
+                        break;
+
+                case 10 ... 19:
+                    frequency = frequency / 2;
+                    note_timbre = TIMBRE_12;
+                        break;
+
+                case 20 ... 200:
+                    note_timbre = .125 - pow(((float)compensated_index - 20) / (200 - 20), 2)*.125;
+                        break;
+
+                default:
+                    note_timbre = 0;
+                        break;
+            }
+            break;
+
+        // case octave_crunch:
+        //     polyphony_rate = 0;
+        //     switch (compensated_index) {
+        //         case 0 ... 9:
+        //         case 20 ... 24:
+        //         case 30 ... 32:
+        //             frequency = frequency / 2;
+        //             note_timbre = TIMBRE_12;
+        //         break;
+
+        //         case 10 ... 19:
+        //         case 25 ... 29:
+        //         case 33 ... 35:
+        //             frequency = frequency * 2;
+        //             note_timbre = TIMBRE_12;
+               //          break;
+
+        //         default:
+        //             note_timbre = TIMBRE_12;
+        //              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 OCS_SPEED 10
+                    #define OCS_AMP   .25
+                    // sine wave is slow
+                    // note_timbre = (sin((float)compensated_index/10000*OCS_SPEED) * OCS_AMP / 2) + .5;
+                    // triangle wave is a bit faster
+                    note_timbre = (float)abs((compensated_index*OCS_SPEED % 3000) - 1500) * ( OCS_AMP / 1500 ) + (1 - OCS_AMP) / 2;
+                        break;
+            }
+                break;
+
+        case duty_octave_down:
+            polyphony_rate = 0;
+            note_timbre = (envelope_index % 2) * .125 + .375 * 2;
+            if ((envelope_index % 4) == 0)
+                note_timbre = 0.5;
+            if ((envelope_index % 8) == 0)
+                note_timbre = 0;
+            break;
+        case delayed_vibrato:
+            polyphony_rate = 0;
+            note_timbre = TIMBRE_50;
+            #define VOICE_VIBRATO_DELAY 150
+            #define VOICE_VIBRATO_SPEED 50
+            switch (compensated_index) {
+                case 0 ... VOICE_VIBRATO_DELAY:
+                    break;
+                default:
+                    frequency = frequency * vibrato_lut[(int)fmod((((float)compensated_index - (VOICE_VIBRATO_DELAY + 1))/1000*VOICE_VIBRATO_SPEED), VIBRATO_LUT_LENGTH)];
+                    break;
+            }
+            break;
+        // case delayed_vibrato_octave:
+        //     polyphony_rate = 0;
+        //     if ((envelope_index % 2) == 1) {
+        //         note_timbre = 0.55;
+        //     } else {
+        //         note_timbre = 0.45;
+        //     }
+        //     #define VOICE_VIBRATO_DELAY 150
+        //     #define VOICE_VIBRATO_SPEED 50
+        //     switch (compensated_index) {
+        //         case 0 ... VOICE_VIBRATO_DELAY:
+        //             break;
+        //         default:
+        //             frequency = frequency * VIBRATO_LUT[(int)fmod((((float)compensated_index - (VOICE_VIBRATO_DELAY + 1))/1000*VOICE_VIBRATO_SPEED), VIBRATO_LUT_LENGTH)];
+        //             break;
+        //     }
+        //     break;
+        // case duty_fifth_down:
+        //     note_timbre = 0.5;
+        //     if ((envelope_index % 3) == 0)
+        //         note_timbre = 0.75;
+        //     break;
+        // case duty_fourth_down:
+        //     note_timbre = 0.0;
+        //     if ((envelope_index % 12) == 0)
+        //         note_timbre = 0.75;
+        //     if (((envelope_index % 12) % 4) != 1)
+        //         note_timbre = 0.75;
+        //     break;
+        // case duty_third_down:
+        //     note_timbre = 0.5;
+        //     if ((envelope_index % 5) == 0)
+        //         note_timbre = 0.75;
+        //     break;
+        // case duty_fifth_third_down:
+        //     note_timbre = 0.5;
+        //     if ((envelope_index % 5) == 0)
+        //         note_timbre = 0.75;
+        //     if ((envelope_index % 3) == 0)
+        //         note_timbre = 0.25;
+        //     break;
+
+                default:
+                        break;
+    }
+
+    return frequency;
+}
+
+