feat: implement clip deletion via 'd' key and CMD_DELETE command

engine/src/command.h

@@ -16,6 +16,7 @@ typedef enum {
     CMD_ADD_SCENE,
     CMD_REMOVE_SCENE,
     CMD_SET_SCENE,
+    CMD_DELETE,
 } cmd_type_t;
 
 typedef struct {

engine/src/looper.c

@@ -279,6 +279,24 @@ static void exec_command(command_t cmd, jack_client_t *client) {
     break;
   }
 
+  case CMD_DELETE: {
+    int dch = cmd.channel;
+    if (dch >= 0 && dch < MAX_CHANNELS) {
+      int dsc_idx = atomic_load(&channels[dch].current_scene);
+      scene_t *dsc = &channels[dch].scenes[dsc_idx];
+      // Reset state to IDLE
+      atomic_store(&dsc->state, STATE_IDLE);
+      atomic_store(&dsc->prev_state, -1);
+      // Clear loop data
+      atomic_store(&dsc->loop_count, 0);
+      atomic_store(&dsc->record_pos, 0);
+      atomic_store(&dsc->playback_pos, 0);
+      // Zero the audio buffer
+      memset(dsc->loop.audio_buffer, 0, sizeof(dsc->loop.audio_buffer));
+    }
+    break;
+  }
+
   default:
     break;
   }

engine/src/pipe.c

@@ -101,6 +101,14 @@ static void *pipe_thread_func(void *arg) {
       } else if (strcmp(line, "save") == 0) {
         command_t cmd = {.type = CMD_SAVE, .channel = -1, .data = 0};
         queue_push(&cmd_queue_main_fifo, cmd);
+      } else if (strncmp(line, "delete", 6) == 0) {
+        int ch = -1;
+        const char *arg = line + 6;
+        while (*arg == ' ') arg++;
+        if (*arg) ch = atoi(arg);
+        fprintf(stderr, "FIFO RECEIVED delete\n");
+        command_t cmd = {.type = CMD_DELETE, .channel = ch, .data = 0};
+        queue_push(&cmd_queue_main_fifo, cmd);
       } else if (strncmp(line, "from ", 5) == 0) {
         const char *port = line + 5;
         fprintf(stderr, "FIFO RECEIVED from: %s\n", port);