[LAD] 64 bit tempo-based time stamp

Hi all, seeking opinions: I have to choose a way to represent beat-based tempo time in 64 bits. Uses are many, but the main one is event time stamps for plugins. Requirements: * No odd data sizes (for performance / programmer ease) * High precision (ideally close to sample accurate for most tempos) * Fits in the same space as two uint32_t's Questions: * Is "bar" needed? * Use floating point? Rounding errors an issue? Options: /* A (moderate range, ultra precise) */ struct { uint16_t bar; uint16_t beat; uint32_t tick; }; /* B (high range, moderate precision) */ struct { uint32_t bar; uint16_t beat; uint16_t tick; }; /* C (high range, good precision?) */ struct { uint32_t bar float beat; }; /* D (high range/precision, but no bar) */ double beat; I havn't run the math on precision yet, but I am leaning towards C. I actually hadn't considered mixing int and float before writing this email, but it seems the best trade-off, and working with float is certainly more pleasant than fixed point. Thoughts? -dr