diff options
author | nick_m <mainsbridge@gmail.com> | 2016-11-04 03:19:21 +1100 |
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committer | nick_m <mainsbridge@gmail.com> | 2016-11-11 03:37:08 +1100 |
commit | 9df27844fc0ea1a241aad588ee0b44f3da44a3ee (patch) | |
tree | 86abd0a9cb4adcad8218205accf4930189d601b7 /libs/ardour/tempo.cc | |
parent | 5788f4243854569096d8c0ba89edc84ca677de22 (diff) |
more tempo documentation.
Diffstat (limited to 'libs/ardour/tempo.cc')
-rw-r--r-- | libs/ardour/tempo.cc | 19 |
1 files changed, 15 insertions, 4 deletions
diff --git a/libs/ardour/tempo.cc b/libs/ardour/tempo.cc index 073e0dc0a8..a5e7defce0 100644 --- a/libs/ardour/tempo.cc +++ b/libs/ardour/tempo.cc @@ -3320,6 +3320,7 @@ TempoMap::gui_dilate_tempo (TempoSection* ts, const framepos_t& frame, const fra /** Returns the exact bbt-based beat corresponding to the bar, beat or quarter note subdivision nearest to * the supplied frame, possibly returning a negative value. + * * @param frame The session frame position. * @param sub_num The subdivision to use when rounding the beat. * A value of -1 indicates rounding to BBT bar. 1 indicates rounding to BBT beats. @@ -3327,11 +3328,17 @@ TempoMap::gui_dilate_tempo (TempoSection* ts, const framepos_t& frame, const fra * 0 indicates that the returned beat should not be rounded (equivalent to quarter_note_at_frame()). * @return The beat position of the supplied frame. * + * when working to a musical grid, the use of sub_nom indicates that + * the position should be interpreted musically. + * + * it effectively snaps to meter bars, meter beats or quarter note divisions + * (as per current gui convention) and returns a musical position independent of frame rate. + * * If the supplied frame lies before the first meter, the return will be negative, * in which case the returned beat uses the first meter (for BBT subdivisions) and * the continuation of the tempo curve (backwards). * - * This function uses both tempo and meter. + * This function is sensitive to tempo and meter. */ double TempoMap::exact_beat_at_frame (const framepos_t& frame, const int32_t sub_num) @@ -3349,8 +3356,6 @@ TempoMap::exact_beat_at_frame_locked (const Metrics& metrics, const framepos_t& /** Returns the exact quarter note corresponding to the bar, beat or quarter note subdivision nearest to * the supplied frame, possibly returning a negative value. - * Supplying a frame position with a non-zero sub_num is equivalent to supplying - * a quarter-note musical position without frame rounding (see below) * * @param frame The session frame position. * @param sub_num The subdivision to use when rounding the quarter note. @@ -3359,11 +3364,17 @@ TempoMap::exact_beat_at_frame_locked (const Metrics& metrics, const framepos_t& * 0 indicates that the returned quarter note should not be rounded (equivalent to quarter_note_at_frame()). * @return The quarter note position of the supplied frame. * + * When working to a musical grid, the use of sub_nom indicates that + * the frame position should be interpreted musically. + * + * it effectively snaps to meter bars, meter beats or quarter note divisions + * (as per current gui convention) and returns a musical position independent of frame rate. + * * If the supplied frame lies before the first meter, the return will be negative, * in which case the returned quarter note uses the first meter (for BBT subdivisions) and * the continuation of the tempo curve (backwards). * - * This function uses both tempo and meter. + * This function is tempo-sensitive. */ double TempoMap::exact_qn_at_frame (const framepos_t& frame, const int32_t sub_num) |