piano roll refactor

1 files changed, 122 insertions, 107 deletions

diff --git a/source/saw/main.c b/source/saw/main.c
index 8250850..9945480 100644
--- a/source/saw/main.c
+++ b/source/saw/main.c
@@ -41,6 +41,16 @@ typedef struct {
   saw_sheet_note_t notes[SHEET_SIZE];
 } saw_sheet_t;
 
+typedef struct {
+  i32         last_index;
+  i8          turned_off[ROLL_SIZE];
+  saw_sheet_t sheet;
+  i8          grid_input;
+  i32         grid_note;
+  i32         grid_pitch;
+  i32         grid_time;
+} saw_roll_t;
+
 static struct NVGcontext *saw_nvg;
 static ma_device          saw_ma;
 
@@ -56,16 +66,17 @@ static i32 saw_voice_pitch[VOICE_COUNT]    = { 0 };
 static i64 saw_voice_time[VOICE_COUNT]     = { 0 };
 static f64 saw_voice_duration[VOICE_COUNT] = { 0 };
 
-static i32         saw_roll_last_index            = -1;
-static i8          saw_roll_turned_off[ROLL_SIZE] = { 0 };
-static saw_sheet_t saw_roll_sheet   = { .rate = 6, .notes = { 0 } };
-static i8          saw_roll_playing = 0;
-static i64         saw_roll_frame   = 0;
+static i8  saw_playback_on    = 0;
+static i64 saw_playback_frame = 0;
 
-static i8  saw_grid_input = 0;
-static i32 saw_grid_note  = 0;
-static i32 saw_grid_pitch = 0;
-static i32 saw_grid_time  = 0;
+static saw_roll_t saw_rolls[1] = { { .last_index = -1,
+                                     .turned_off = { 0 },
+                                     .sheet      = { .rate  = 6,
+                                                     .notes = { 0 } },
+                                     .grid_input = 0,
+                                     .grid_note  = 0,
+                                     .grid_pitch = 0,
+                                     .grid_time  = 0 } };
 
 #ifdef __GNUC__
 #  pragma GCC diagnostic push
@@ -94,17 +105,19 @@ static f64 saw_envelope(f64 t, f64 attack, f64 decay, f64 sustain,
     return 0.;
 }
 
-static void saw_roll_playback(i32 frame_count) {
-  if (!saw_roll_playing)
+static void saw_playback(i32 frame_count) {
+  if (!saw_playback_on)
     return;
 
+  saw_roll_t *roll = saw_rolls;
+
   for (i32 i = 0; i < SHEET_SIZE; i++) {
-    saw_sheet_note_t *p = saw_roll_sheet.notes + i;
+    saw_sheet_note_t *p = roll->sheet.notes + i;
     if (!p->enabled)
       continue;
-    i64 frame = (p->time * SAW_SAMPLE_RATE) / saw_roll_sheet.rate;
-    if (saw_roll_frame + frame_count <= frame ||
-        saw_roll_frame > frame)
+    i64 frame = (p->time * SAW_SAMPLE_RATE) / roll->sheet.rate;
+    if (saw_playback_frame + frame_count <= frame ||
+        saw_playback_frame > frame)
       continue;
     if (saw_voice_on[VOICE_COUNT - 1])
       continue;
@@ -119,15 +132,15 @@ static void saw_roll_playback(i32 frame_count) {
     saw_voice_on[0]       = 1;
     saw_voice_pitch[0]    = p->pitch;
     saw_voice_time[0]     = 0;
-    saw_voice_duration[0] = ((f64) p->duration) / saw_roll_sheet.rate;
+    saw_voice_duration[0] = ((f64) p->duration) / roll->sheet.rate;
   }
 
-  saw_roll_frame += frame_count;
+  saw_playback_frame += frame_count;
 }
 
 static void saw_audio(ma_device *device, void *void_out_,
                       void const *void_in_, ma_uint32 frame_count) {
-  saw_roll_playback(frame_count);
+  saw_playback(frame_count);
 
   f32 *out = (f32 *) void_out_;
 
@@ -173,49 +186,12 @@ static void saw_audio(ma_device *device, void *void_out_,
 #  pragma GCC diagnostic pop
 #endif
 
-static void saw_init(void) {
-  sapp_set_window_title("saw");
-
-#ifdef SOKOL_GLCORE33
-  saw_nvg = nvgCreateGL3(NVG_ANTIALIAS | NVG_STENCIL_STROKES);
-#else
-  saw_nvg = nvgCreateGLES3(NVG_ANTIALIAS | NVG_STENCIL_STROKES);
-#endif
-
-  ma_device_config config = ma_device_config_init(
-      ma_device_type_playback);
-
-  config.playback.format   = ma_format_f32;
-  config.playback.channels = SAW_CHANNEL_COUNT;
-  config.sampleRate        = SAW_SAMPLE_RATE;
-  config.dataCallback      = saw_audio;
-  config.pUserData         = NULL;
-
-  if (ma_device_init(NULL, &config, &saw_ma) != MA_SUCCESS) {
-    printf("ma_device_init failed.\n");
-    return;
-  }
-
-  ma_device_start(&saw_ma);
-}
-
-static void saw_frame(void) {
-  i32 width  = sapp_width();
-  i32 height = sapp_height();
-
-  glViewport(0, 0, width, height);
-  glClearColor(.23f, .19f, .16f, 1.f);
-  glClearDepth(1.);
-  glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT |
-          GL_STENCIL_BUFFER_BIT);
-
-  nvgBeginFrame(saw_nvg, width, height, sapp_dpi_scale());
-
+static void saw_ui_roll(saw_roll_t *roll, i64 x0, i64 y0, i64 width,
+                        i64 height) {
   //  Piano roll
   //
 
-  i32 x0 = 20;
-  i32 y0 = 20;
+  i32 frame_height = sapp_height();
 
   i32 pianokey_height = 35;
   i32 pianokey_width  = 100;
@@ -228,13 +204,14 @@ static void saw_frame(void) {
 
   for (i32 pitch = 0; pitch < ROLL_SIZE; pitch++) {
     i32 x = x0 + roll_border;
-    i32 y = height - y0 - (pitch + 1) * pianokey_height + roll_border;
+    i32 y = frame_height - y0 - (pitch + 1) * pianokey_height +
+            roll_border;
     i32 w = pianokey_width - roll_border * 2;
     i32 h = pianokey_height - roll_border * 2;
 
-    if (y > height - pianokey_height)
+    if (y > y0 + height)
       continue;
-    if (y < 0)
+    if (y < y0)
       break;
 
     nvgBeginPath(saw_nvg);
@@ -243,7 +220,7 @@ static void saw_frame(void) {
     i8 has_cursor = saw_mouse_x >= x && saw_mouse_x < x + w &&
                     saw_mouse_y >= y && saw_mouse_y < y + h;
 
-    nvgFillColor(saw_nvg, saw_roll_turned_off[pitch]
+    nvgFillColor(saw_nvg, roll->turned_off[pitch]
                               ? nvgRGBA(220, 220, 220, 160)
                           : has_cursor ? nvgRGBA(200, 200, 255, 255)
                                        : nvgRGBA(220, 220, 220, 255));
@@ -255,9 +232,9 @@ static void saw_frame(void) {
     if (has_cursor) {
       hover_any = 1;
 
-      if (!saw_roll_turned_off[pitch] &&
+      if (!roll->turned_off[pitch] &&
           (saw_lbutton_click ||
-           (saw_lbutton_down && saw_roll_last_index != pitch)) &&
+           (saw_lbutton_down && roll->last_index != pitch)) &&
           !saw_voice_on[VOICE_COUNT - 1]) {
         for (i32 n = VOICE_COUNT - 1; n > 0; --n) {
           saw_voice_on[n]       = saw_voice_on[n - 1];
@@ -273,24 +250,24 @@ static void saw_frame(void) {
       }
 
       if (saw_rbutton_click)
-        saw_roll_turned_off[pitch] = !saw_roll_turned_off[pitch];
+        roll->turned_off[pitch] = !roll->turned_off[pitch];
 
-      saw_roll_last_index = pitch;
+      roll->last_index = pitch;
     }
   }
 
   if (!hover_any)
-    saw_roll_last_index = -1;
+    roll->last_index = -1;
 
   //  Draw music sheet
   //
 
   for (i32 pitch = 0; pitch < ROLL_SIZE; pitch++) {
-    i32 y = height - y0 - (pitch + 1) * pianokey_height;
+    i32 y = frame_height - y0 - (pitch + 1) * pianokey_height;
 
-    if (y > height - pianokey_height)
+    if (y > y0 + height - pianokey_height)
       continue;
-    if (y < 0)
+    if (y < y0)
       break;
 
     i32 h = pianokey_height;
@@ -298,13 +275,13 @@ static void saw_frame(void) {
     for (i32 t = 0;; t++) {
       i32 x = x0 + pianokey_width + sheet_offset + t * sheet_scale;
 
-      if (x >= width - roll_border)
+      if (x >= x0 + width - roll_border)
         break;
 
       i32 note = -1;
 
       for (i32 n = 0; n < SHEET_SIZE; n++) {
-        saw_sheet_note_t *p = saw_roll_sheet.notes + n;
+        saw_sheet_note_t *p = roll->sheet.notes + n;
         if (p->enabled && p->pitch == pitch && t >= p->time &&
             t < p->time + p->duration) {
           note = n;
@@ -327,7 +304,7 @@ static void saw_frame(void) {
         has_cursor = saw_mouse_x >= x && saw_mouse_x < x + w &&
                      saw_mouse_y >= y && saw_mouse_y < y + h;
 
-        nvgFillColor(saw_nvg, saw_roll_turned_off[pitch]
+        nvgFillColor(saw_nvg, roll->turned_off[pitch]
                                   ? nvgRGBA(160, 150, 120, 100)
                               : has_cursor
                                   ? nvgRGBA(180, 180, 220, 160)
@@ -337,27 +314,27 @@ static void saw_frame(void) {
         //  Empty cell input
         //
 
-        if (!saw_grid_input && !saw_roll_turned_off[pitch] &&
+        if (!roll->grid_input && !roll->turned_off[pitch] &&
             has_cursor && saw_lbutton_click) {
           for (i32 n = 0; n < SHEET_SIZE; n++)
-            if (!saw_roll_sheet.notes[n].enabled) {
-              saw_roll_sheet.notes[n] = (saw_sheet_note_t) {
+            if (!roll->sheet.notes[n].enabled) {
+              roll->sheet.notes[n] = (saw_sheet_note_t) {
                 .enabled = 1, .time = t, .duration = 1, .pitch = pitch
               };
-              saw_grid_input = 1;
-              saw_grid_note  = n;
-              saw_grid_pitch = pitch;
-              saw_grid_time  = t;
+              roll->grid_input = 1;
+              roll->grid_note  = n;
+              roll->grid_pitch = pitch;
+              roll->grid_time  = t;
               break;
             }
         }
       } else {
-        i32 w = sheet_scale * saw_roll_sheet.notes[note].duration;
+        i32 w = sheet_scale * roll->sheet.notes[note].duration;
 
         has_cursor = saw_mouse_x >= x && saw_mouse_x < x + w &&
                      saw_mouse_y >= y && saw_mouse_y < y + h;
 
-        if (t == saw_roll_sheet.notes[note].time) {
+        if (t == roll->sheet.notes[note].time) {
           //  Draw note
           //
 
@@ -374,7 +351,7 @@ static void saw_frame(void) {
           //
 
           if (has_cursor && saw_rbutton_down)
-            saw_roll_sheet.notes[note].enabled = 0;
+            roll->sheet.notes[note].enabled = 0;
         }
       }
     }
@@ -383,63 +360,101 @@ static void saw_frame(void) {
   //  Note stretching input
   //
 
-  if (saw_grid_input) {
+  if (roll->grid_input) {
     if (saw_lbutton_down) {
       i32 t = (saw_mouse_x - x0 - pianokey_width - sheet_offset) /
               sheet_scale;
 
       if (t >= 0) {
-        saw_sheet_note_t *p = saw_roll_sheet.notes + saw_grid_note;
-        if (saw_grid_time <= t) {
-          p->time     = saw_grid_time;
-          p->duration = 1 + t - saw_grid_time;
+        saw_sheet_note_t *p = roll->sheet.notes + roll->grid_note;
+        if (roll->grid_time <= t) {
+          p->time     = roll->grid_time;
+          p->duration = 1 + t - roll->grid_time;
         } else {
           p->time     = t;
-          p->duration = saw_grid_time - t;
+          p->duration = roll->grid_time - t;
         }
       }
 
-      saw_sheet_note_t *p = saw_roll_sheet.notes + saw_grid_note;
+      saw_sheet_note_t *p = roll->sheet.notes + roll->grid_note;
       for (i32 n = 0; n < SHEET_SIZE; n++) {
-        if (n == saw_grid_note)
+        if (n == roll->grid_note)
           continue;
-        saw_sheet_note_t *q = saw_roll_sheet.notes + n;
+        saw_sheet_note_t *q = roll->sheet.notes + n;
         if (!q->enabled || q->pitch != p->pitch)
           continue;
-        if (q->time < saw_grid_time &&
+        if (q->time < roll->grid_time &&
             q->time + q->duration > p->time) {
           p->time     = q->time + q->duration;
-          p->duration = saw_grid_time > p->time
-                            ? saw_grid_time - p->time
+          p->duration = roll->grid_time > p->time
+                            ? roll->grid_time - p->time
                             : 1;
         }
-        if (q->time > saw_grid_time &&
+        if (q->time > roll->grid_time &&
             q->time < p->time + p->duration) {
-          p->time     = saw_grid_time;
-          p->duration = q->time - saw_grid_time;
+          p->time     = roll->grid_time;
+          p->duration = q->time - roll->grid_time;
           assert(p->duration > 0);
         }
       }
     } else
-      saw_grid_input = 0;
+      roll->grid_input = 0;
   }
 
   //  Playback indicator
   //
 
-  f64 playback_time = ((f64) saw_roll_frame) / SAW_SAMPLE_RATE;
+  f64 playback_time = ((f64) saw_playback_frame) / SAW_SAMPLE_RATE;
 
   i32 x = x0 + pianokey_width + sheet_offset - roll_border * 2 +
-          (i32) (playback_time * saw_roll_sheet.rate * sheet_scale +
-                 .5);
-  i32 y = 0;
+          (i32) (playback_time * roll->sheet.rate * sheet_scale + .5);
   i32 w = roll_border * 4;
-  i32 h = height - y0;
 
   nvgBeginPath(saw_nvg);
-  nvgRect(saw_nvg, x, y, w, h);
+  nvgRect(saw_nvg, x, y0, w, height);
   nvgFillColor(saw_nvg, nvgRGBA(240, 240, 80, 220));
   nvgFill(saw_nvg);
+}
+
+static void saw_init(void) {
+  sapp_set_window_title("saw");
+
+#ifdef SOKOL_GLCORE33
+  saw_nvg = nvgCreateGL3(NVG_ANTIALIAS | NVG_STENCIL_STROKES);
+#else
+  saw_nvg = nvgCreateGLES3(NVG_ANTIALIAS | NVG_STENCIL_STROKES);
+#endif
+
+  ma_device_config config = ma_device_config_init(
+      ma_device_type_playback);
+
+  config.playback.format   = ma_format_f32;
+  config.playback.channels = SAW_CHANNEL_COUNT;
+  config.sampleRate        = SAW_SAMPLE_RATE;
+  config.dataCallback      = saw_audio;
+  config.pUserData         = NULL;
+
+  if (ma_device_init(NULL, &config, &saw_ma) != MA_SUCCESS) {
+    printf("ma_device_init failed.\n");
+    return;
+  }
+
+  ma_device_start(&saw_ma);
+}
+
+static void saw_frame(void) {
+  i32 frame_width  = sapp_width();
+  i32 frame_height = sapp_height();
+
+  glViewport(0, 0, frame_width, frame_height);
+  glClearColor(.23f, .19f, .16f, 1.f);
+  glClearDepth(1.);
+  glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT |
+          GL_STENCIL_BUFFER_BIT);
+
+  nvgBeginFrame(saw_nvg, frame_width, frame_height, sapp_dpi_scale());
+
+  saw_ui_roll(saw_rolls, 0, 0, frame_width, frame_height);
 
   nvgEndFrame(saw_nvg);
 
@@ -493,9 +508,9 @@ static void saw_event(sapp_event const *event) {
       if (!event->key_repeat) {
         switch (event->key_code) {
           case SAPP_KEYCODE_SPACE:
-            saw_roll_playing = !saw_roll_playing;
+            saw_playback_on = !saw_playback_on;
             break;
-          case SAPP_KEYCODE_ENTER: saw_roll_frame = 0; break;
+          case SAPP_KEYCODE_ENTER: saw_playback_frame = 0; break;
           default:;
         }
       }