Track();
void clear();
+ bool empty() const;
- void set_key(long tm, float val);
- float get_key(long tm) const;
+ int get_num_keys() const;
+
+ const TrackKey &operator [](int idx) const;
+ TrackKey &operator [](int idx);
+
+ void set_value(long tm, float val);
+ float get_value(long tm) const;
int find_key(long tm) const;
float operator ()(long tm) const;