Add voice stealing

1 files changed, 113 insertions, 18 deletions

diff --git a/src/app.c b/src/app.c
index 4f52d89..aeb5c84 100644
--- a/src/app.c
+++ b/src/app.c
@@ -119,6 +119,7 @@ u16 font_numbers[10] = {
 // Enums and structs.
 typedef enum Button {
     POLY_PAD_ACTIVE = 11,
+    POLY_PAD_STEAL  = 11 + 7,
     POLY_PAD_MIN_CH_0 = 11 + 10 * 7 + 0,
     POLY_PAD_MIN_CH_1 = 11 + 10 * 7 + 1,
     POLY_PAD_MIN_CH_2 = 11 + 10 * 7 + 2,
@@ -170,10 +171,17 @@ typedef enum Button {
 } Button;
 
 typedef enum Mode {
-    MOD_POLY_MAIN = 0,
+    MOD_POLY_MAIN  = 0,
     MOD_POLY_SETUP = 1,
 } Mode;
 
+typedef enum Stealing {
+    POLY_STEAL_OFF  = 0,
+    POLY_STEAL_OLD  = 1,
+    POLY_STEAL_HIGH = 2,
+    POLY_STEAL_LOW  = 3,
+} Stealing;
+
 typedef struct Voice {
     u8 active;
     u8 channel;
@@ -186,10 +194,11 @@ typedef struct Voice {
 typedef struct State {
     // Polyphony.
     u8 active;
+    u8 stealing;
     u8 ch_min;
     u8 ch_max;
     u8 ch_listen[16];
-    Mode mode;
+    u8 mode;
 } State;
 
 // Globals.
@@ -198,6 +207,8 @@ u16 n_voices = 0;
 Voice voices[16] = {0};
 State state = {0};
 u32 note_counter = 0;
+u8 midi_in_connected = 0;
+u8 midi_out_connected = 0;
 
 // store ADC frame pointer
 static const u16 *g_ADC = 0;
@@ -225,6 +236,15 @@ poly_active_toggle(void) {
 }
 
 void
+poly_steal_cycle(void) {
+    poly_stop_all();
+    state.stealing += 1;
+    if (state.stealing > POLY_STEAL_LOW) {
+        state.stealing = POLY_STEAL_OFF;
+    }
+}
+
+void
 select_ch_min(u8 target) {
     if (target <= state.ch_max) {
         state.ch_min = target;
@@ -250,8 +270,12 @@ app_surface_event(u8 type, u8 index, u8 value) {
         case  TYPEPAD: {
             switch (state.mode) {
                 case MOD_POLY_MAIN: {
-                    if (value && index == POLY_PAD_ACTIVE) {
-                        poly_active_toggle();
+                    if (value) {
+                        switch (index) {
+                            case POLY_PAD_ACTIVE: { poly_active_toggle(); } break;
+                            case POLY_PAD_STEAL:  { poly_steal_cycle();   } break;
+                            default: break;
+                        }
                     }
                 } break;
                 case MOD_POLY_SETUP: {
@@ -310,6 +334,7 @@ app_surface_event(u8 type, u8 index, u8 value) {
                             case POLY_PAD_SEL_CH_F: { select_ch_sel(15); } break;
                             // Handle active toggle.
                             case POLY_PAD_ACTIVE: { poly_active_toggle(); } break;
+                            case POLY_PAD_STEAL:  { poly_steal_cycle();   } break;
                             default: break;
                         }
                     }
@@ -346,9 +371,51 @@ app_midi_event(u8 port, u8 status, u8 d1, u8 d2) {
         return;
     }
     if ((status & 0xF0) == NOTEON) {
-        // TODO: Only do this if voice stealing is disabled.
         if (n_voices == (state.ch_max - state.ch_min + 1)) {
-            return;
+            u8 selected = 0;
+            switch (state.stealing) {
+                case POLY_STEAL_OFF: {
+                    return;
+                } break;
+                case POLY_STEAL_OLD: {
+                    u32 age = -1;
+                    for (u8 i = state.ch_min; i <= state.ch_max; i++) {
+                        Voice *voice = &voices[i];
+                        if (voice->age < age) {
+                            age = voice->age;
+                            selected = i;
+                        }
+                    }
+                } break;
+                case POLY_STEAL_HIGH: {
+                    u8 pitch = 0;
+                    for (u8 i = state.ch_min; i <= state.ch_max; i++) {
+                        Voice *voice = &voices[i];
+                        if (voice->d1 >= pitch) {
+                            pitch = voice->d1;
+                            selected = i;
+                        }
+                    }
+                } break;
+                case POLY_STEAL_LOW: {
+                    u8 pitch = -1;
+                    for (u8 i = state.ch_min; i <= state.ch_max; i++) {
+                        Voice *voice = &voices[i];
+                        if (voice->d1 < pitch) {
+                            pitch = voice->d1;
+                            selected = i;
+                        }
+                    }
+                } break;
+            }
+
+            Voice *voice = &voices[selected];
+            voice->active = 0;
+            hal_send_midi(voice->port,
+                NOTEOFF | voice->channel,
+                voice->d1,
+                voice->d2);
+            n_voices--;
         }
 
         // Find if the note was already pressed.
@@ -384,9 +451,6 @@ app_midi_event(u8 port, u8 status, u8 d1, u8 d2) {
             }
         }
 
-        // TODO: if there are no free slots choose the oldest active one.
-        // TODO:     - Send noteoff message for the previous active channel.
-        // TODO: Round robin scheduling?
         n_voices++;
     } else if ((status & 0xF0) == NOTEOFF) {
         for (u8 i = state.ch_min; i <= state.ch_max; i++) {
@@ -406,22 +470,33 @@ app_midi_event(u8 port, u8 status, u8 d1, u8 d2) {
 
 void
 app_sysex_event(u8 port, u8 * data, u16 count) {
-    // example - respond to UDI messages?
+    // ...
 }
 
 void
 app_aftertouch_event(u8 index, u8 value) {
-    // example - send poly aftertouch to MIDI ports
-    // hal_send_midi(USBMIDI, POLYAFTERTOUCH | 0, index, value);
+    // ...
 }
 
 void
 app_cable_event(u8 type, u8 value) {
-    // example - light the Setup LED to indicate cable connections
     if (type == MIDI_IN_CABLE) {
-        hal_plot_led(TYPESETUP, 0, 0, value, 0); // green
+        if (value) {
+            midi_in_connected = 1;
+        } else {
+            midi_in_connected = 0;
+        }
     } else if (type == MIDI_OUT_CABLE) {
-        hal_plot_led(TYPESETUP, 0, value, 0, 0); // red
+        if (value) {
+            midi_out_connected = 1;
+        } else {
+            midi_out_connected = 0;
+        }
+    }
+    if (midi_in_connected && midi_out_connected) {
+        hal_plot_led(TYPESETUP, 0, 0, value, 0);
+    } else {
+        hal_plot_led(TYPESETUP, 0, value, 0, 0);
     }
 }
 
@@ -462,9 +537,27 @@ clear_pads(void) {
 void
 draw_poly_active_button(void) {
     if (state.active) {
-        hal_plot_led(TYPEPAD, 11, 0, MAXLED, 0);
+        hal_plot_led(TYPEPAD, POLY_PAD_ACTIVE, 0, MAXLED, 0);
     } else {
-        hal_plot_led(TYPEPAD, 11, MAXLED, 0, 0);
+        hal_plot_led(TYPEPAD, POLY_PAD_ACTIVE, MAXLED, 0, 0);
+    }
+}
+
+void
+draw_poly_steal_button(void) {
+    switch (state.stealing) {
+        case POLY_STEAL_OFF: {
+            hal_plot_led(TYPEPAD, POLY_PAD_STEAL, MAXLED, 0, 0);
+        } break;
+        case POLY_STEAL_OLD: {
+            hal_plot_led(TYPEPAD, POLY_PAD_STEAL, 0, 24, 24);
+        } break;
+        case POLY_STEAL_HIGH: {
+            hal_plot_led(TYPEPAD, POLY_PAD_STEAL, 0, 24, 0);
+        } break;
+        case POLY_STEAL_LOW: {
+            hal_plot_led(TYPEPAD, POLY_PAD_STEAL, 0, 0, 24);
+        } break;
     }
 }
 
@@ -473,6 +566,7 @@ draw_poly_main(void) {
     print_number((n_voices / 10) % 10, MAXLED, MAXLED, MAXLED, 0, 0);
     print_number(       n_voices % 10, MAXLED, MAXLED, MAXLED, 4, 0);
     draw_poly_active_button();
+    draw_poly_steal_button();
 }
 
 void
@@ -547,10 +641,10 @@ draw_sel_channel(void) {
 
 void
 draw_poly_setup(void) {
-    // TODO: ...
     draw_min_channel();
     draw_max_channel();
     draw_sel_channel();
+    draw_poly_steal_button();
     draw_poly_active_button();
 }
 
@@ -586,6 +680,7 @@ app_init(const u16 *adc_raw) {
     // example - load button states from flash
     state = (State){
         .active = 1,
+        .stealing = POLY_STEAL_OFF,
         .ch_min = 0,
         .ch_max = 7,
         .ch_listen = {1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1},