From 8fc15953b2c10a8f06169b4ccbc6b16c86b205b2 Mon Sep 17 00:00:00 2001
From: Bad Diode <bd@badd10de.dev>
Date: Wed, 8 Feb 2023 17:49:45 +0100
Subject: Add initial poly midi splitter

---
 src/app.c | 121 +++++++++++++++++++++++++++++++++++++++++---------------------
 1 file changed, 81 insertions(+), 40 deletions(-)

(limited to 'src')

diff --git a/src/app.c b/src/app.c
index 9258965..27f88f1 100644
--- a/src/app.c
+++ b/src/app.c
@@ -34,7 +34,16 @@
 
 // Housekeeping and debugging.
 u16 frame = 0;
-u16 value = 0;
+u16 n_voices = 0;
+
+typedef struct Voice {
+    u8 active;
+    u8 channel;
+    u8 d1;
+    u8 d2;
+} Voice;
+
+Voice voices[16] = {0};
 
 // store ADC frame pointer
 static const u16 *g_ADC = 0;
@@ -127,42 +136,74 @@ u16 font_numbers[10] = {
 
 void
 app_surface_event(u8 type, u8 index, u8 value) {
-    switch (type) {
-        case  TYPEPAD: {
-            // toggle it and store it off, so we can save to flash if we want to
-            if (value) {
-                buttons[index] = MAXLED * !buttons[index];
-            }
+    // switch (type) {
+    //     case  TYPEPAD: {
+    //         // toggle it and store it off, so we can save to flash if we want to
+    //         if (value) {
+    //             buttons[index] = MAXLED * !buttons[index];
+    //         }
 
-            // example - light / extinguish pad LEDs
-            // hal_plot_led(TYPEPAD, index, 0, 0, buttons[index]);
-
-            // example - send MIDI
-            // hal_send_midi(DINMIDI, NOTEON | 0, index, value);
-        } break;
-        case TYPESETUP: {
-            if (value) {
-                // Pressing the setup button will save the current buttons/pad
-                // state to the flash. The flash memory is USER_AREA_SIZE bytes
-                // long and can be organized however we need.
-                hal_write_flash(0, buttons, BUTTON_COUNT);
-            }
-        } break;
-    }
+    //         // example - light / extinguish pad LEDs
+    //         hal_plot_led(TYPEPAD, index, 0, 0, buttons[index]);
+
+    //         // example - send MIDI
+    //         hal_send_midi(DINMIDI, NOTEON | 0, index, value);
+    //     } break;
+    //     case TYPESETUP: {
+    //         if (value) {
+    //             // Pressing the setup button will save the current buttons/pad
+    //             // state to the flash. The flash memory is USER_AREA_SIZE bytes
+    //             // long and can be organized however we need.
+    //             hal_write_flash(0, buttons, BUTTON_COUNT);
+    //         }
+    //     } break;
+    // }
 }
 
 void
 app_midi_event(u8 port, u8 status, u8 d1, u8 d2) {
-    if (port == USBMIDI) {
-        hal_send_midi(DINMIDI, status, d1, d2);
-    }
-    if (port == DINMIDI) {
-        hal_send_midi(USBMIDI, status, d1, d2);
-    }
+    u8 channel = status & 0x0F;
     if ((status & 0xF0) == NOTEON) {
-        value++;
+        // Find if the note was already pressed.
+        for (u8 i = 0; i < 16; i++) {
+            Voice *voice = &voices[i];
+            // Register voice.
+            if (voice->active && voice->d1 == d1) {
+                voice->active = 0;
+                hal_send_midi(port, NOTEOFF | i, d1, d2);
+                break;
+            }
+        }
+
+        // Find next free voice slot.
+        for (u8 i = 0; i < 16; i++) {
+            Voice *voice = &voices[i];
+            // Register voice.
+            if (!voice->active) {
+                voice->active = 1;
+                voice->channel = i;
+                voice->d1 = d1;
+                voice->d2 = d2;
+                hal_send_midi(port, NOTEON | i, d1, d2);
+                break;
+            }
+        }
+        // TODO: if there are no free slots choose the oldest active one.
+        // TODO:     - Send noteoff message for the previous active channel.
+        // TODO: send noteon message.
+        n_voices++;
     } else if ((status & 0xF0) == NOTEOFF) {
-        value--;
+        for (u8 i = 0; i < 16; i++) {
+            Voice *voice = &voices[i];
+            // Register voice.
+            if (voice->active && voice->d1 == d1) {
+                voice->active = 0;
+                hal_send_midi(port, NOTEOFF | i, d1, d2);
+                break;
+            }
+        }
+        n_voices--;
+        // hal_send_midi(port, status, d1, d2);
     }
 }
 
@@ -180,11 +221,11 @@ app_aftertouch_event(u8 index, u8 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
-    // } else if (type == MIDI_OUT_CABLE) {
-    //     hal_plot_led(TYPESETUP, 0, value, 0, 0); // red
-    // }
+    if (type == MIDI_IN_CABLE) {
+        hal_plot_led(TYPESETUP, 0, 0, value, 0); // green
+    } else if (type == MIDI_OUT_CABLE) {
+        hal_plot_led(TYPESETUP, 0, value, 0, 0); // red
+    }
 }
 
 void
@@ -204,14 +245,14 @@ print_number(u8 n, u16 r, u16 g, u16 b, u8 x, u8 y) {
 void
 update(void) {
     // for (int i = 0; i < PAD_COUNT; ++i) {
-    //     // Get the first detected button value.
+    //     // Get the first detected button n_voices.
 		// u16 x = (99 * g_ADC[i]) >> 12;
     //     if (x > 3) {
-    //         value = x;
+    //         n_voices = x;
     //         return;
     //     }
     // }
-    // value = 0;
+    // n_voices = 0;
 }
 
 void
@@ -225,8 +266,8 @@ void
 render(void) {
     if (frame++ == 1000 / 10) {
         clear_pads();
-        print_number((value / 10) % 10, MAXLED, MAXLED, MAXLED, 0, 0);
-        print_number(       value % 10, MAXLED, MAXLED, MAXLED, 4, 0);
+        print_number((n_voices / 10) % 10, MAXLED, MAXLED, MAXLED, 0, 0);
+        print_number(       n_voices % 10, MAXLED, MAXLED, MAXLED, 4, 0);
         frame = 0;
     }
 }
-- 
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