1 files changed, 47 insertions, 0 deletions
diff --git a/src/track.h b/src/track.h
new file mode 100644
index 0000000..fd59ded
--- /dev/null
+++ b/src/track.h
@@ -0,0 +1,47 @@
+#ifndef SYNC_TRACK_H
+#define SYNC_TRACK_H
+
+#include <string.h>
+#include <stdlib.h>
+#include "base.h"
+
+enum key_type {
+	KEY_STEP,   /* stay constant */
+	KEY_LINEAR, /* lerp to the next value */
+	KEY_SMOOTH, /* smooth curve to the next value */
+	KEY_RAMP,
+	KEY_TYPE_COUNT
+};
+
+struct track_key {
+	int row;
+	float value;
+	enum key_type type;
+};
+
+struct sync_track {
+	char *name;
+	struct track_key *keys;
+	int num_keys;
+};
+
+int sync_find_key(const struct sync_track *, int);
+static inline int key_idx_floor(const struct sync_track *t, int row)
+{
+	int idx = sync_find_key(t, row);
+	if (idx < 0)
+		idx = -idx - 2;
+	return idx;
+}
+
+#ifndef SYNC_PLAYER
+int sync_set_key(struct sync_track *, const struct track_key *);
+int sync_del_key(struct sync_track *, int);
+static inline int is_key_frame(const struct sync_track *t, int row)
+{
+	return sync_find_key(t, row) >= 0;
+}
+
+#endif /* !defined(SYNC_PLAYER) */
+
+#endif /* SYNC_TRACK_H */