Pythagorean tuning

2 files changed, 174 insertions, 49 deletions

diff --git a/TODO b/TODO
index c1cca77..29ddeb3 100644
--- a/TODO
+++ b/TODO
@@ -56,6 +56,7 @@ Done
   - Buffering
   - Drag & drop audio files
   - Sampler
+  - Pythagorean tuning
 
 - UI
   - Piano roll
diff --git a/source/saw/main.c b/source/saw/main.c
index f9773c0..38c1b58 100644
--- a/source/saw/main.c
+++ b/source/saw/main.c
@@ -83,14 +83,17 @@ enum {
 #else
   TRACK_COUNT  = 16,
   ROLL_COUNT   = 32,
-  PITCH_COUNT  = 80,
+  PITCH_COUNT  = 100,
   VOICE_COUNT  = 32,
   UNISON_COUNT = 100,
   SHEET_SIZE   = 200,
 #endif
 
   ROLL_DEFAULT_RATE        = 8,
-  ROLL_DEFAULT_UI_OFFSET_Y = 710,
+  ROLL_DEFAULT_UI_OFFSET_Y = 2000,
+
+  TUNING_EQUAL_TEMPERAMENT = 0,
+  TUNING_PYTHAGOREAN,
 
   WAVE_SINE = 0,
   WAVE_SAW_UP,
@@ -124,6 +127,7 @@ enum {
 
   TINT_WHITE = 0,
   TINT_ORANGE,
+  TINT_PINK,
 };
 
 //  Data types
@@ -151,6 +155,8 @@ typedef struct {
   i64             track;
   b8              pitch_turned_off[PITCH_COUNT];
   f64             tuning[PITCH_COUNT];
+  i64             tuning_tag;
+  i64             mark_pitch;
   i64             rate;
   saw_roll_note_t notes[SHEET_SIZE];
   i64             time;
@@ -292,15 +298,23 @@ static saw_compose_t saw_compose = {
 
 static saw_ui_color_t saw_ui_colors[] = {
   {
+      // TINT_WHITE
       .normal = { .7f, .7f, .7f, .7f },
       .active = { .7f, .7f, .7f, 1.f },
       .hover  = { 1.f, 1.f, 1.f, 1.f },
   },
   {
+      // TINT_ORANGE
       .normal = { .9f, .65f, .4f, .6f },
       .active = { .9f, .65f, .4f, 1.f },
       .hover  = { 1.f, 1.f, 1.f, 1.f },
   },
+  {
+      // TINT_PINK
+      .normal = { .7f, .3f, .6f, .7f },
+      .active = { .8f, .25f, .6f, 1.f },
+      .hover  = { 1.f, 1.f, 1.f, 1.f },
+  }
 };
 
 static i64 saw_ui_input_index  = 0;
@@ -326,10 +340,51 @@ static void saw_tuning_equal_temperament(f64 *tuning) {
   if (tuning == NULL)
     return;
 
-  for (i64 i = 0; i < PITCH_COUNT; ++i) {
+  for (i64 i = 0; i < PITCH_COUNT; ++i)
     tuning[i] = REFERENCE_PITCH *
                 pow(EQUAL_TEMPERAMENT_FACTOR,
                     (f64) (i - REFERENCE_PITCH_INDEX));
+}
+
+static void saw_tuning_pythagorean(f64 *tuning, i64 base_pitch) {
+  assert(tuning != NULL && base_pitch >= 0 &&
+         base_pitch < PITCH_COUNT);
+  if (tuning == NULL || base_pitch < 0 || base_pitch >= PITCH_COUNT)
+    return;
+
+  f64 ref_freq = tuning[base_pitch];
+
+  f64 v[12] = {
+    ref_freq,                // unison
+    ref_freq * 256. / 243.,  // minor second
+    ref_freq * 9. / 8.,      // major second
+    ref_freq * 32. / 27.,    // minor third
+    ref_freq * 81. / 64.,    // major third
+    ref_freq * 4. / 3.,      // perfect fourth
+    ref_freq * 1024. / 729., // diminished fifth
+    ref_freq * 3. / 2.,      // perfect fifth
+    ref_freq * 128. / 81.,   // minor sixth
+    ref_freq * 27. / 16.,    // major sixth
+    ref_freq * 16. / 9.,     // minor seventh
+    ref_freq * 243. / 128.,  // major seventh
+  };
+
+  for (i64 i = 0; i < PITCH_COUNT && i < base_pitch; i++) {
+    i64 octave = (base_pitch - i + 11) / 12;
+    i64 k      = i - (base_pitch - 12 * octave);
+    assert(k >= 0 && k < 12);
+    tuning[i] = v[k] * pow(.5, octave);
+  }
+
+  for (i64 i = base_pitch; i < PITCH_COUNT && i < base_pitch + 12;
+       i++)
+    tuning[i] = v[i - base_pitch];
+
+  for (i64 i = base_pitch + 12; i < PITCH_COUNT; i++) {
+    i64 octave = (i - base_pitch) / 12;
+    i64 k      = (i - base_pitch) % 12;
+    assert(k >= 0 && k < 12);
+    tuning[i] = v[k] * pow(2., octave);
   }
 }
 
@@ -367,12 +422,15 @@ static f64 saw_pitch_amplitude(i64 pitch) {
 
 static void saw_play_voice(saw_track_t *track, saw_roll_t *roll,
                            i64 pitch, i64 duration) {
-  if (saw_voices[VOICE_COUNT - 1].enabled)
+  if (saw_voices[VOICE_COUNT - 1].enabled || pitch < 0 ||
+      pitch >= PITCH_COUNT)
     return;
 
   for (i32 n = VOICE_COUNT - 1; n > 0; --n)
     saw_voices[n] = saw_voices[n - 1];
 
+  f64 frequency = roll->tuning[pitch];
+
   switch (track->instrument) {
       //  FIXME
       //  Apply volume during sound generation.
@@ -386,7 +444,7 @@ static void saw_play_voice(saw_track_t *track, saw_roll_t *roll,
         .enabled   = 1,
         .time      = 0,
         .duration  = (f64) duration / (f64) SAMPLE_RATE,
-        .frequency = saw_pitch_frequency(pitch),
+        .frequency = frequency,
         .amplitude = saw_pitch_amplitude(pitch) * osc->volume,
         .phase = {
           saw_random(-s, s),
@@ -403,7 +461,7 @@ static void saw_play_voice(saw_track_t *track, saw_roll_t *roll,
         .enabled   = 1,
         .time      = 0,
         .duration  = (f64) duration / (f64) SAMPLE_RATE,
-        .frequency = saw_pitch_frequency(pitch),
+        .frequency = frequency,
         .amplitude = saw_pitch_amplitude(pitch) * sam->volume,
         .phase     = { 0., 0., },
         .track     = roll->track,
@@ -1341,6 +1399,8 @@ static void saw_ui_compose(i64 x0, i64 y0, i64 width, i64 height) {
           .track            = track,
           .pitch_turned_off = { 0 },
           .tuning           = { 0 },
+          .tuning_tag       = TUNING_EQUAL_TEMPERAMENT,
+          .mark_pitch       = REFERENCE_PITCH_INDEX,
           .rate             = ROLL_DEFAULT_RATE,
           .notes            = { 0 },
           .time             = frame,
@@ -1908,6 +1968,28 @@ static void saw_ui_roll(saw_roll_t *roll, i64 x0, i64 y0, i64 width,
           title.values, title.values + title.size);
   nvgFill(saw_nvg);
 
+  //  Tuning control
+  //
+  {
+    i64 x = x0 + border;
+    i64 y = y0 + height - text_height - header_height;
+    i64 w = pianokey_width;
+    i64 h = header_height;
+
+    if (saw_ui_button(x, y, w / 2, h, TINT_PINK, SZ("\uf52d"), SZ(""),
+                      roll->tuning_tag == TUNING_PYTHAGOREAN)) {
+      saw_tuning_pythagorean(roll->tuning, roll->mark_pitch);
+      roll->tuning_tag = TUNING_PYTHAGOREAN;
+    }
+
+    if (saw_ui_button(x + w / 2, y, w / 2, h, TINT_PINK, SZ("\uf5ac"),
+                      SZ(""),
+                      roll->tuning_tag == TUNING_EQUAL_TEMPERAMENT)) {
+      saw_tuning_equal_temperament(roll->tuning);
+      roll->tuning_tag = TUNING_EQUAL_TEMPERAMENT;
+    }
+  }
+
   //  Loop control
   //
   {
@@ -1925,8 +2007,9 @@ static void saw_ui_roll(saw_roll_t *roll, i64 x0, i64 y0, i64 width,
       nvgFillColor(saw_nvg, nvgRGBA(80, 80, 80, 160));
     else
       nvgFillColor(saw_nvg, nvgRGBA(180, 80, 40, 200));
-    nvgText(saw_nvg, x - header_height * 2 + border,
-            y + header_height - border, repeat,
+    nvgTextAlign(saw_nvg, NVG_ALIGN_CENTER | NVG_ALIGN_MIDDLE);
+    nvgText(saw_nvg, x - header_height / 2 - border,
+            y + header_height / 2, repeat,
             repeat + (sizeof repeat - 1));
 
     i64 rw = (roll->loop_duration * roll->rate * sheet_scale +
@@ -1983,57 +2066,93 @@ static void saw_ui_roll(saw_roll_t *roll, i64 x0, i64 y0, i64 width,
 
   //  Piano roll
   //
-
-  b8 hover_any = 0;
-
-  for (i64 pitch = 0; pitch < PITCH_COUNT; pitch++) {
-    i64 x = x0 + border;
-    i64 y = frame_height - y0 - (pitch + 1) * pianokey_height +
-            border + roll->ui_offset_y;
+  {
     i64 w = pianokey_width - border * 2;
     i64 h = pianokey_height - border * 2;
 
-    if (y > frame_height - y0 - pianokey_height)
-      continue;
-    if (y < frame_height - y0 - height + text_height + header_height)
-      break;
+    b8 hover_any = 0;
 
-    nvgBeginPath(saw_nvg);
-    nvgRect(saw_nvg, x, y, w, h);
+    for (i64 pitch = 0; pitch < PITCH_COUNT; pitch++) {
+      i64 x = x0 + border;
+      i64 y = frame_height - y0 - (pitch + 1) * pianokey_height +
+              border + roll->ui_offset_y;
+      if (y > frame_height - y0 - pianokey_height)
+        continue;
+      if (y <
+          frame_height - y0 - height + text_height + header_height)
+        break;
 
-    b8 has_cursor = saw_mouse_x >= x && saw_mouse_x < x + w &&
-                    saw_mouse_y >= y && saw_mouse_y < y + h;
+      b8 has_cursor = saw_mouse_x >= x && saw_mouse_x < x + w &&
+                      saw_mouse_y >= y && saw_mouse_y < y + h;
 
-    nvgFillColor(saw_nvg, roll->pitch_turned_off[pitch]
-                              ? nvgRGBA(220, 220, 220, 160)
-                          : has_cursor ? nvgRGBA(200, 200, 255, 255)
-                                       : nvgRGBA(220, 220, 220, 255));
-    nvgFill(saw_nvg);
+      nvgBeginPath(saw_nvg);
+      nvgRect(saw_nvg, x, y, w, h);
+      nvgFillColor(saw_nvg, roll->pitch_turned_off[pitch]
+                                ? nvgRGBA(220, 220, 220, 160)
+                            : has_cursor
+                                ? nvgRGBA(200, 200, 255, 255)
+                                : nvgRGBA(220, 220, 220, 255));
+      nvgFill(saw_nvg);
 
-    //  Piano roll input
-    //
+      nvgFontSize(saw_nvg, h / 2);
 
-    if (has_cursor) {
-      hover_any = 1;
+      if (pitch == roll->mark_pitch) {
+        nvgFontFaceId(saw_nvg, saw_font_icons);
+        nvgFillColor(saw_nvg, nvgRGBAf(.1f, .1f, .1f, 1.f));
+        nvgTextAlign(saw_nvg, NVG_ALIGN_CENTER | NVG_ALIGN_MIDDLE);
+        nvgText(saw_nvg, x + w / 3, y + h / 2, "\uf52d", NULL);
+      }
 
-      if (!roll->pitch_turned_off[pitch] &&
-          ((saw_edit_mode == EDIT_MODE_HAND && saw_lbutton_click) ||
-           (saw_edit_mode == EDIT_MODE_HAND && saw_lbutton_down &&
-            roll->last_index != pitch)))
-        saw_play_voice(saw_tracks + roll->track, roll, pitch,
-                       SAMPLE_RATE / roll->rate);
+      char        buf[64];
+      char const *note_names[12] = {
+        "A",  "Bb", "H", "C",  "Db", "D",
+        "Eb", "E",  "F", "Gb", "G",  "Ab",
+      };
 
-      if (saw_rbutton_click ||
-          (saw_edit_mode == EDIT_MODE_ERASE && saw_lbutton_click))
-        roll->pitch_turned_off[pitch] =
-            !roll->pitch_turned_off[pitch];
+      sprintf(buf, "%s",
+              note_names[pitch %
+                         (sizeof note_names / sizeof *note_names)]);
 
-      roll->last_index = pitch;
+      nvgFontFaceId(saw_nvg, saw_font_text);
+      nvgFillColor(saw_nvg, nvgRGBAf(.1f, .1f, .1f, 1.f));
+      nvgTextAlign(saw_nvg, NVG_ALIGN_LEFT | NVG_ALIGN_MIDDLE);
+      nvgText(saw_nvg, x + border, y + h / 2, buf, NULL);
+
+      memset(buf, 0, sizeof buf);
+      sprintf(buf, "%.1f", (f32) roll->tuning[pitch]);
+
+      nvgFontSize(saw_nvg, (h * 2) / 3);
+      nvgFillColor(saw_nvg, nvgRGBAf(.1f, .1f, .1f, 1.f));
+      nvgTextAlign(saw_nvg, NVG_ALIGN_RIGHT | NVG_ALIGN_MIDDLE);
+      nvgText(saw_nvg, x + w, y + h / 2, buf, NULL);
+
+      //  Piano roll input
+      //
+
+      if (has_cursor) {
+        hover_any = 1;
+
+        if (!roll->pitch_turned_off[pitch] &&
+            ((saw_edit_mode == EDIT_MODE_HAND && saw_lbutton_click) ||
+             (saw_edit_mode == EDIT_MODE_HAND && saw_lbutton_down &&
+              roll->last_index != pitch))) {
+          saw_play_voice(saw_tracks + roll->track, roll, pitch,
+                         SAMPLE_RATE / roll->rate);
+          roll->mark_pitch = pitch;
+        }
+
+        if (saw_rbutton_click ||
+            (saw_edit_mode == EDIT_MODE_ERASE && saw_lbutton_click))
+          roll->pitch_turned_off[pitch] =
+              !roll->pitch_turned_off[pitch];
+
+        roll->last_index = pitch;
+      }
     }
-  }
 
-  if (!hover_any)
-    roll->last_index = -1;
+    if (!hover_any)
+      roll->last_index = -1;
+  }
 
   //  Panning input
   //
@@ -2405,7 +2524,7 @@ static void saw_init(void) {
   //  Init Saw state
   //
 
-  f64 tuning[PITCH_COUNT];
+  static f64 tuning[PITCH_COUNT];
 
   saw_tuning_equal_temperament(tuning);
 
@@ -2418,6 +2537,8 @@ static void saw_init(void) {
       .last_index       = -1,
       .pitch_turned_off = { 0 },
       .tuning           = { 0 },
+      .tuning_tag       = TUNING_EQUAL_TEMPERAMENT,
+      .mark_pitch       = REFERENCE_PITCH_INDEX,
       .rate             = ROLL_DEFAULT_RATE,
       .notes            = { 0 },
       .time             = 0,
@@ -2548,7 +2669,6 @@ static void saw_init(void) {
         roll->pitch_turned_off[pitch] = flag ? 1 : 0;
       }
 
-#if 0
       SCAN_(" tuning %d", 1, &pitch_count);
 
       if (pitch_count < 0 || pitch_count > PITCH_COUNT) {
@@ -2563,7 +2683,9 @@ static void saw_init(void) {
         SCAN_(" %lld", 1, &frequency);
         roll->tuning[pitch] = .0001 * frequency;
       }
-#endif
+
+      SCAN_(" tuning_tag %lld", 1, &roll->tuning_tag);
+      SCAN_(" mark_pitch %lld", 1, &roll->mark_pitch);
 
       SCAN_(" rate %lld", 1, &roll->rate);
 
@@ -2908,6 +3030,8 @@ static void saw_cleanup(void) {
       fprintf(f, " %lld",
               (i64) floor(roll->tuning[pitch] * 10000 + .5));
     fprintf(f, "\n");
+    fprintf(f, "tuning_tag        %lld\n", roll->tuning_tag);
+    fprintf(f, "mark_pitch        %lld\n", roll->mark_pitch);
     fprintf(f, "rate              %lld\n", roll->rate);
 
     i32 total_notes = 0;