clarify midi-iterator comment
This commit is contained in:
parent
b3e9231a4e
commit
e2902a0b76
@ -218,18 +218,18 @@ MidiSource::midi_read (const Lock& lm,
|
||||
* "parallel playback of linked midi regions -> no note-offs"
|
||||
*
|
||||
* A midi source can be used by multiple tracks simultaneously,
|
||||
* in which case midi_read() can called from different tracks for
|
||||
* in which case midi_read() may be called from different tracks for
|
||||
* overlapping time-ranges.
|
||||
*
|
||||
* However there is only a single iterator for a given midi-source.
|
||||
* this results in every midi_read() performing a seek.
|
||||
* This results in every midi_read() performing a seek.
|
||||
*
|
||||
* if seeking is performed with
|
||||
* If seeking is performed with
|
||||
* _model->begin(converter.from(start),...)
|
||||
* the model is used for seeking. That method seeks to the first
|
||||
* *note-on* event after 'start'.
|
||||
*
|
||||
* _model->begin(conveter.from( ) ,..) eventually calls
|
||||
* _model->begin(converter.from( ) ,..) eventually calls
|
||||
* Sequence<Time>::const_iterator() in libs/evoral/src/Sequence.cpp
|
||||
* which looks up the note-event via seq.note_lower_bound(t);
|
||||
* but the sequence 'seq' only contains note-on events(!).
|
||||
@ -237,10 +237,14 @@ MidiSource::midi_read (const Lock& lm,
|
||||
* via _active_notes.pop(); and not part of seq.
|
||||
*
|
||||
* see also http://tracker.ardour.org/view.php?id=6287#c16671
|
||||
* and call 1-900-ardour-midi ($4.99/min)
|
||||
*
|
||||
* The linear search below assures that reading starts at the first
|
||||
* event for the given time, regardless of its event-type.
|
||||
*
|
||||
* The performance of this approach is O(N), while the previous
|
||||
* implementation is O(log(N)). This needs to be optimized:
|
||||
* The model-iterator or event-sequence needs to be re-designed in
|
||||
* some way (maybe keep an iterator per playlist).
|
||||
*/
|
||||
for (i = _model->begin(); i != _model->end(); ++i) {
|
||||
const framecnt_t time_frames = converter.to(i->time());
|
||||
|
Loading…
Reference in New Issue
Block a user