Sawtooth and square oscillators

1 files changed, 47 insertions, 15 deletions

diff --git a/source/saw/main.c b/source/saw/main.c
index 3c9accc..d8f0aa6 100644
--- a/source/saw/main.c
+++ b/source/saw/main.c
@@ -42,6 +42,11 @@ enum {
   ROLL_DEFAULT_OFFSET_Y = 710,
 
   INSTRUMENT_SINE = 0,
+  INSTRUMENT_SAW_UP,
+  INSTRUMENT_SAW_DOWN,
+  INSTRUMENT_SQUARE_UP,
+  INSTRUMENT_SQUARE_DOWN,
+  INSTRUMENT_COUNT,
 
   TRACK_INPUT_NONE = 0,
   TRACK_INPUT_INSTRUMENT,
@@ -259,6 +264,21 @@ static void saw_playback(i32 frame_count) {
   saw_playback_frame += frame_count;
 }
 
+static f64 saw_oscillator(i32 type, f64 t, f64 warp) {
+  f64 n = t - floor(t);
+
+  switch (type) {
+    case INSTRUMENT_SINE: return sin(n * (M_PI * 2));
+    case INSTRUMENT_SAW_UP: return -1. + n * 2.;
+    case INSTRUMENT_SAW_DOWN: return 1. - n * 2.;
+    case INSTRUMENT_SQUARE_UP: return n < .5 + warp / 2. ? -1. : 1.;
+    case INSTRUMENT_SQUARE_DOWN: return n < .5 + warp / 2. ? 1. : -1.;
+    default:;
+  }
+
+  return 0.;
+}
+
 static void saw_audio(ma_device *device, void *void_out_,
                       void const *void_in_, ma_uint32 frame_count) {
   saw_playback(frame_count);
@@ -276,7 +296,8 @@ static void saw_audio(ma_device *device, void *void_out_,
 
     saw_track_t *track = saw_tracks + saw_voices[n].track;
 
-    f64 period    = M_PI * 2.;
+    i32 wave_type = track->instrument;
+    f64 warp      = track->warp;
     f64 frequency = saw_voices[n].frequency;
     f64 amplitude = saw_voices[n].amplitude;
     f64 phase_l   = track->phase + saw_voices[n].phase[0];
@@ -292,10 +313,14 @@ static void saw_audio(ma_device *device, void *void_out_,
       f64 t = (f64) saw_voices[n].time / (f64) SAW_SAMPLE_RATE;
       f64 a = amplitude * saw_envelope(t, attack, decay, sustain,
                                        duration, release);
-      out[i * 2] += (f32) (sin((t * frequency + phase_l) * period) *
+      out[i * 2] += (f32) (saw_oscillator(wave_type,
+                                          t * frequency + phase_l,
+                                          warp) *
                            a);
-      out[i * 2 + 1] +=
-          (f32) (sin((t * frequency + phase_r) * period) * a);
+      out[i * 2 + 1] += (f32) (saw_oscillator(wave_type,
+                                              t * frequency + phase_r,
+                                              warp) *
+                               a);
 
       saw_voices[n].time++;
 
@@ -683,7 +708,7 @@ static void saw_ui_track(saw_track_t *track, i64 x0, i64 y0,
 
         switch (input_index) {
           case TRACK_INPUT_INSTRUMENT:
-            track->value_buffer = track->instrument * 100;
+            track->value_buffer = track->instrument * 500;
             break;
 
           case TRACK_INPUT_UNISON:
@@ -748,11 +773,12 @@ static void saw_ui_track(saw_track_t *track, i64 x0, i64 y0,
           title.values, title.values + title.size);
   next_y = header_offset + text_height;
 
-  char buf_instr[][100] = { "Sine" };
+  char buf_instr[][100] = { "Sine", "Saw up", "Saw down", "Square up",
+                            "Square down" };
   nvgText(saw_nvg, x0 + border * 2,
           frame_height - y0 - height + next_y - border * 2,
           "Instrument", 0);
-  if (track->instrument >= 0 && track->instrument <= INSTRUMENT_SINE)
+  if (track->instrument >= 0 && track->instrument < INSTRUMENT_COUNT)
     nvgText(saw_nvg, x0 + column_width + border * 2,
             frame_height - y0 - height + next_y - border * 2,
             buf_instr[track->instrument], 0);
@@ -954,9 +980,9 @@ static void saw_ui_roll(saw_roll_t *roll, i64 x0, i64 y0, i64 width,
     i32 y = frame_height - y0 - (pitch + 1) * pianokey_height +
             roll->offset_y;
 
-    if (y + border > frame_height - y0 - pianokey_height)
+    if (y > frame_height - y0 - pianokey_height)
       continue;
-    if (y + border < frame_height - y0 - height + text_height)
+    if (y < frame_height - y0 - height + text_height)
       break;
 
     i32 h = pianokey_height;
@@ -1041,10 +1067,10 @@ static void saw_ui_roll(saw_roll_t *roll, i64 x0, i64 y0, i64 width,
     i32 y = frame_height - y0 - (note->pitch + 1) * pianokey_height +
             roll->offset_y;
 
-    if (y + border > frame_height - y0 - pianokey_height)
+    if (y + pianokey_height > frame_height - y0)
+      continue;
+    if (y < frame_height - y0 - height + text_height)
       continue;
-    if (y + border < frame_height - y0 - height + text_height)
-      break;
 
     i64 x = x0 + pianokey_width + sheet_offset + roll->offset_x +
             (note->time * roll->rate * sheet_scale) / SAW_SAMPLE_RATE;
@@ -1056,6 +1082,8 @@ static void saw_ui_roll(saw_roll_t *roll, i64 x0, i64 y0, i64 width,
                     (saw_mouse_x >= x && saw_mouse_x < x + w &&
                      saw_mouse_y >= y && saw_mouse_y < y + h);
 
+    if (x >= x0 + width)
+      continue;
     if (x + w - sheet_scale < x0 + pianokey_width + sheet_offset)
       continue;
 
@@ -1256,7 +1284,7 @@ static void saw_init(void) {
   for (i32 i = 0; i < TRACK_COUNT; i++)
     saw_tracks[i] = (saw_track_t) {
       .instrument   = INSTRUMENT_SINE,
-      .warp         = .5,
+      .warp         = .0,
       .phase        = .0,
       .unison       = 1,
       .spread       = .1,
@@ -1618,8 +1646,12 @@ static void saw_event(sapp_event const *event) {
 
         switch (track->value_input) {
           case TRACK_INPUT_INSTRUMENT:
-            //  TODO
-            //
+            track->instrument = (i64) (track->value_buffer * .002 +
+                                       0.5);
+            if (track->instrument < 0)
+              track->instrument = 0;
+            if (track->instrument >= INSTRUMENT_COUNT)
+              track->instrument = INSTRUMENT_COUNT - 1;
             break;
 
           case TRACK_INPUT_WARP: