1 files changed, 60 insertions, 0 deletions

diff --git a/quantum/audio/voices.c b/quantum/audio/voices.c
new file mode 100644
index 000000000..51652927b
--- /dev/null
+++ b/quantum/audio/voices.c
@@ -0,0 +1,60 @@
+#include "voices.h"
+
+extern uint16_t envelope_index;
+extern float note_timbre;
+
+voice_type voice = default_voice;
+
+void set_voice(voice_type v) {
+    voice = v;
+}
+
+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
+        break;
+        case butts_fader:
+            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:
+            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;
+    }
+
+    return frequency;
+}
\ No newline at end of file