24 std::vector<TrackKey> keys;
25 mutable bool keys_sorted;
27 int get_interval(long tm) const;
39 int get_num_keys() const;
41 const TrackKey &operator [](int idx) const;
42 TrackKey &operator [](int idx);
44 void set_value(long tm, float val);
45 float get_value(long tm) const;
46 int find_key(long tm) const;
48 float operator ()(long tm) const;