c++ - How can I store data to be accessed as if along a value line? -

c++ - How can I store data to be accessed as if along a value line? -

i working on model importer simple game engine, importing handled simple (for lovely compatibility) i'm stuck on how should organize bones , animations.

as each bone holding list of timing values , matrices (a timing , matrix per keyframe), i'd of course of study need access matrices using value won't exact keyframe time, how store info in such way may nearest matrix of lower timing value , nearest matrix of higher timing value, may interpolate them?

c++ animation dictionary map linear