- for those not in the know, this series provides a way to
remove the temporal distortion introduced when using an
audio frame-based gui for music-locked objects.
In short, the gui uses an audio frame representation to move
objects. It displays the object using frame_at_beat(), quantizing
the time value to audio frames. This is fine until the user selects
that frame but expects it to be interpreted as a beat.
Thus beat_at_frame() would not produce the user-expected beat
(temporal quantization error of up to 0.5 audio samples).
This is one method of mapping audio time to music time accurately.
Each MidiRegionView(MRV) is connected to the Selection::ClearMidiNoteSelection
signal that is used to notify the all MRV instances to clear their note
selection.
The MRV class also has a private static SelectionCleared signal that is used to
signal other MRV instances when their selection has been cleared. When the
Selection::ClearMidiNoteSelection signal is emitted it causes each MRV to also
emit the SelectionCleared signal. So the emission takes quadratic time.
With 1500 MRV instances emission takes about 2.2 seconds on my machine, and
some operations like track selection cause it to be emitted 3 times(another
issue).
The Selection class in the Editor knows which MRV instances have note
selections, as it is notified by MidiRegionView whenever the selection count
becomes zero or becomes non-zero. Clearing the Note selection should then just
be O(N) and direct calls can be used rather than signals.
This change removes both the signals and uses the existing references between
Selection and MRV class to control note selection. There should be no
behavioural changes in Midi note selection with this change.
I don't think this is necessary, if some synth cannot deal with that,
perhaps Ardour could try to send the note off right before the next
note on, even-though they supposedly occur simultaneously.
The shortcut for 'change velocities together' had to be changed to
achieve that. The new shortcut is now primary+tertiary modifier +scroll,
i.e. ctrl+shift+scroll for the default keys.
Currently when a GhostRegion is deleted by its "parent" RegionView it emits the
static GhostRegion::CatchDeletion signal which is connected to the
RegionView::remove_ghost method of every RegionView instance.
With a static GhostRegion::CatchDeletion signal a particular test session
causes 31 Million calls of RegionView::remove_ghost on Session deletion and the
session takes 70 seconds to close with a debug build.
The lifetime of a ghost region is tied to both the TimeAxisView(TAV) and
RegionView(RV) in that when a RegionView is deleted all GhostRegion instances
associated with the RegionView should be deleted or when a TimeAxisView is
deleted all ghost regions that are contained in the view should be deleted.
This means that there needs to be notification between GhostRegion and both
classes. Instead of using a signal for this as we know there are only two
listeners and GhostRegion already holds a reference to the TimeAxisView, also
take a reference to the parent RegionView in the GhostRegion constructor and
use it to notify the RegionView when GhostRegion destructor is called so it can
drop any references it holds.
Using a direct function call in the GhostRegion destructor to notify the
TimeAxisView and RegionView "parents" brings the unload/close time down for the
test session from 70 seconds to 4.5 seconds.
The GhostRegion also references canvas items that are added to the TimeAxisView
canvas group or at least a canvas group that it manages. So when the
TimeAxisView is destroyed and the canvas group that is the parent of those
items is destroyed, the GhostRegion's canvas items will also be
deleted/destroyed by the parent canvas item/group. This means the GhostRegions
must be destroyed when the TimeAxisView they are contained in is destroyed or
there will be dangling references to canvas items that have already been
deleted and trying to delete them again will be bad.
NoteBaseDeleted signal is static so each MidiRegionView(MRV) gets notified
about the deletion of each NodeBase instance even if it is contained in another
MRV
The NoteBase and MRV classes are currently coupled anyway, so this change uses
the reference to the MRV parent to directly call the parent when the NoteBase
is deleted. This is all in the GUI thread so I'm not sure why a PBD::Signal was
being used?
If the MRV class is the only reference holder to the NoteBase class
then I'm not sure if a callback is needed, perhaps the MRV should just remove
the note from the selection before deleting it but I'm not that familiar with
the code.
Signal emission/calls static NoteBaseDeleted signal vs direct with 10540
NoteBase instances.
static:
After Load Session: 6360638
After Unload Session: 12221026(5860388)
direct:
After load Session: 10540
After unload Session: 21080
Session Load/Unload time in master, debug/release with ~10000 Notes(seconds)
Load Debug: 32, 26
Unload Debug: 83
Load Release 32, 20, 42
Unload Release 26, 25
Session Load/Unload time with direct call debug/release(seconds)
Load Debug: 21.7, 18.1
Unload Debug: 69.4, 71
Load Release: 22.6, 13.4, 17.7
Unload Release: 24, 23.5
This is not a large Session, 1500 regions, 10000 notes so there is probably
some other funky stuff going on that needs fixing.
