From ada32733c5168dd6b57244e995eef35d0841b49a Mon Sep 17 00:00:00 2001 From: John Emmas Date: Thu, 27 Aug 2015 12:24:21 +0100 Subject: [PATCH] Modify some functions to alleviate overflow / precision errors 'session_frame_to_track_frame()' and its complement, 'track_frame_to_session_frame()' both accept a double and an ARDOUR::framepost_t (int64_t). For convenience these both get converted to long double. However, the functions are often called with very large values (ARDOUR::max_framepos). When this happens, rounding and precision errors can cause overflow issues. This is an attempt to alleviate that problem. Not sure if it's strictly necessary to accommodate negative values - but I'm assuming these could happen if 'speed' was negative (reverse play?) This is the reason why 'Select All Objects' (and similar functionality) don't work for some users. --- libs/ardour/ardour/types.h | 21 +++++++++++++++++++-- 1 file changed, 19 insertions(+), 2 deletions(-) diff --git a/libs/ardour/ardour/types.h b/libs/ardour/ardour/types.h index 17e0b0d7e4..08fe0ef75b 100644 --- a/libs/ardour/ardour/types.h +++ b/libs/ardour/ardour/types.h @@ -713,13 +713,30 @@ LIBARDOUR_API std::ostream& operator<<(std::ostream& o, const ARDOUR::MeterLineU static inline ARDOUR::framepos_t session_frame_to_track_frame (ARDOUR::framepos_t session_frame, double speed) { - return (ARDOUR::framepos_t) ((long double) session_frame * (long double) speed); + long double result = (long double) session_frame * (long double) speed; + + if (result >= (long double) ARDOUR::max_framepos) { + return ARDOUR::max_framepos; + } else if (result <= (long double) (ARDOUR::max_framepos) * (ARDOUR::framepos_t)(-1)) { + return (ARDOUR::max_framepos * (ARDOUR::framepos_t)(-1)); + } else { + return result; + } } static inline ARDOUR::framepos_t track_frame_to_session_frame (ARDOUR::framepos_t track_frame, double speed) { - return (ARDOUR::framepos_t) ((long double) track_frame / (long double) speed); + /* NB - do we need a check for speed == 0 ??? */ + long double result = (long double) track_frame / (long double) speed; + + if (result >= (long double) ARDOUR::max_framepos) { + return ARDOUR::max_framepos; + } else if (result <= (long double) (ARDOUR::max_framepos) * (ARDOUR::framepos_t)(-1)) { + return (ARDOUR::max_framepos * (ARDOUR::framepos_t)(-1)); + } else { + return result; + } } /* for now, break the rules and use "using" to make this "global" */