1 files changed, 137 insertions, 0 deletions
diff --git a/src/sounds.h b/src/sounds.h
new file mode 100644
index 0000000..e58ae4f
--- /dev/null
+++ b/src/sounds.h
@@ -0,0 +1,137 @@
+#ifndef SOUNDS_H_
+#define SOUNDS_H_
+
+#include <alsa/asoundlib.h>
+#include <math.h>
+#include <pthread.h>
+#include <stdbool.h>
+#include <limits.h>
+
+#define check(ret)                                                          \
+	do {                                                                    \
+		int res = (ret);                                                    \
+		if (res < 0) {                                                      \
+			fprintf(stderr, "%s:%d ERROR: %s (%d)\n",                       \
+				__FILE__, __LINE__, snd_strerror(res), res);                \
+			exit(1);                                                        \
+		}                                                                   \
+	} while (0)
+
+#define MESSAGE_QUEUE_SIZE 128
+#define SAMPLE_RATE 48000
+#define PERIOD_SIZE 480
+
+typedef enum {
+  PARAM_OSC,
+  PARAM_VOLUME,
+} param_type;
+
+typedef enum {
+  OSC_SINE,
+  OSC_SAW,
+  OSC_SQUARE,
+  OSC_TRIANGLE,
+} oscilator_type;
+
+typedef enum {
+  MSG_NOTE_ON,
+  MSG_NOTE_OFF,
+  MSG_ALL_NOTES_OFF,
+  MSG_PARAM_CHANGE,
+  MSG_STOP,
+} synth_message_type;
+
+typedef struct {
+  synth_message_type type;
+
+  union {
+	// NOTE_ON / NOTE_OFF
+	struct {
+	  size_t note_id;
+	} note;
+
+	// SET_PARAM;
+	struct {
+	  param_type param_type;
+	  float value;
+	} param_change;
+  };
+} synth_message;
+
+
+typedef struct {
+  synth_message buffer[MESSAGE_QUEUE_SIZE];
+  size_t head;
+  size_t tail;
+  pthread_mutex_t lock;
+} message_queue;
+
+typedef struct {
+  snd_pcm_t *pcm;
+  message_queue *queue;
+} sound_thread_meta;
+
+typedef struct {
+  bool active;
+  float freq;
+  float phase;
+  float phase_inc;
+} synth_voice;
+
+typedef struct {
+  synth_voice *buffer;
+  size_t size;
+} synth_voices;
+
+typedef struct {
+  oscilator_type oscilator_type;
+  float master_volume;
+} synth_params;
+
+typedef void (*oscilator_func)(float *buffer, size_t sample_count, float *phase, float phase_inc);
+
+#define mqueue_init(q) \
+  do { \
+    (q)->head = (q)->tail = 0; \
+    pthread_mutex_init(&(q)->lock, NULL); \
+  } while (0)
+
+
+#define mqueue_push(q, msg) \
+  do { \
+	pthread_mutex_lock(&(q)->lock); \
+	size_t next = ((q)->head + 1) % MESSAGE_QUEUE_SIZE; \
+	 \
+	if ((q)->tail == next) { \
+	  pthread_mutex_unlock(&(q)->lock); \
+	  return 1; \
+	} \
+	 \
+	(q)->buffer[(q)->head] = msg; \
+	(q)->head = next; \
+	 \
+	pthread_mutex_unlock(&(q)->lock); \
+  } while (0) \
+
+/* #define mqueue_get(q, msg, ok) \ */
+/*   do { \ */
+/*     pthread_mutex_lock(&(q)->lock); \ */
+/*     if ((q)->tail == (q)->head) { \ */
+/*       pthread_mutex_unlock(&(q)->lock); \ */
+/*       *(ok) = false;\ */
+/*   	  break; \ */
+/*     } \ */
+/*    \ */
+/*     *(msg) = (q)->buffer[(q)->tail]; \ */
+/*     (q)->tail = ((q)->tail + 1) % MESSAGE_QUEUE_SIZE; \ */
+/*    \ */
+/*     pthread_mutex_unlock(&(q)->lock); \ */
+/*     *(ok) = true; \ */
+/*   } while (0) */
+
+#define mqueue_empty(q) (q)->head == (q)->tail
+
+void *sound_thread_start(void *ptr);
+int set_hw_params(snd_pcm_t *pcm);
+
+#endif // SOUNDS_H_