feat: add 8x8 scene/channel grid, MIDI clock sync, and quantization engine

Co-authored-by: aider (deepseek/deepseek-coder) <aider@aider.chat>

engine.h

@@ -6,8 +6,15 @@
 #include <stdint.h>
 #include <stdbool.h>
 
-#define MAX_CLIPS 128
+#define MAX_SCENES 8
+#define MAX_CHANNELS 8
+#define MAX_CLIPS (MAX_SCENES * MAX_CHANNELS)  // 64
 #define MAX_BUFFER_SIZE 441000  // 10 seconds at 44.1kHz
+#define MIDI_CLOCKS_PER_BEAT 24
+#define BEATS_PER_BAR 4
+
+// Convert scene/channel to flat clip index
+#define CLIP_INDEX(scene, channel) ((scene) * MAX_CHANNELS + (channel))
 
 typedef enum {
     CLIP_EMPTY,
@@ -16,6 +23,20 @@ typedef enum {
     CLIP_STOPPED
 } ClipState;
 
+typedef enum {
+    QUANTIZE_OFF,
+    QUANTIZE_BEAT,
+    QUANTIZE_BAR
+} QuantizeMode;
+
+typedef struct {
+    bool rolling;
+    uint32_t clock_count;
+    uint32_t beat_position;  // 0-3
+    uint32_t bar_position;
+    uint32_t sample_position;  // derived from clock at current sample rate
+} TransportState;
+
 typedef struct {
     ClipState state;
     float *buffer;
@@ -25,17 +46,36 @@ typedef struct {
     bool is_playing;
 } Clip;
 
+// Queued trigger for quantization
+typedef struct QueuedTrigger {
+    int clip_index;
+    bool is_scene;
+    jack_nframes_t trigger_time;
+    struct QueuedTrigger *next;
+} QueuedTrigger;
+
 typedef struct {
     jack_client_t *client;
-    jack_port_t *audio_in_port;
-    jack_port_t *audio_out_port;
-    jack_port_t *midi_in_port;
+    jack_port_t *audio_in_ports[MAX_CHANNELS];
+    jack_port_t *audio_out_ports[MAX_CHANNELS];
+    jack_port_t *midi_in_port;           // Control channel MIDI
+    jack_port_t *midi_scene_in_port;     // Scene launch MIDI
+    jack_port_t *midi_clock_in_port;     // MIDI clock input
     jack_port_t *midi_out_port;
     
     Clip clips[MAX_CLIPS];
     int control_channel;
     jack_nframes_t sample_rate;
     
+    // Transport and clock
+    TransportState transport;
+    bool clock_sync_enabled;
+    
+    // Quantization
+    QuantizeMode quantize_mode;
+    jack_nframes_t quantize_threshold;  // in samples (lookahead)
+    QueuedTrigger *queued_triggers;
+    
     bool running;
 } Engine;
 
@@ -47,10 +87,20 @@ void engine_stop(Engine *engine);
 
 // Clip management
 void engine_trigger_clip(Engine *engine, int clip_index);
+void engine_trigger_scene(Engine *engine, int scene_index);
 void engine_reset_clip(Engine *engine, int clip_index);
 
+// Transport
+void engine_set_quantize_mode(Engine *engine, QuantizeMode mode);
+void engine_set_quantize_threshold(Engine *engine, jack_nframes_t samples);
+void engine_reset_transport(Engine *engine);
+
+// Queue management (exposed for testing)
+void queue_trigger(Engine *engine, int clip_index, bool is_scene, jack_nframes_t time);
+
 // Utility
 const char* clip_state_to_string(ClipState state);
 uint8_t clip_state_to_velocity(ClipState state);
+const char* quantize_mode_to_string(QuantizeMode mode);
 
 #endif // ENGINE_H