If some plugin-internal state changes (GUI <> Plugin e.g. load a sample)
no ports change and the host does not know that the plugin state has
changed. The session may be closed without save.
This is a prototype using an ardour.org URI, pending upstream lv2plug.in
This is needed for save-as and archiving, LV2 state may not be saved
otherwise if lilv_state_equals() returns true.
Also if thestate is saved as part of save-as or archiving or
template, the state-version did increase.
Upcoming normal save will reference a plugin state that does not exist
in the current session bundle.
and also allow immediate work during use latency-compute runs.
At session load, Ardour calls a plugins "set default" state (GUI thread).
Some plugins may schedule work during state-restore. Ardour immediately
proceeded to restore the actual session plugin state without processing
the already scheduled work and without calling run() for a plugin
to apply state synchronously.
This mostly fixes an issue with notifying plugins about tempo-ramps
and BPM changes.
remaining to be fixed (in tempo.h):
```
_session.tempo_map().metric_at(frame_position).tempo().beats_per_minute()
```
currently returns the most recent *fixed* tempo at or before
`frame_position`. All other Plugin types are affected by this as well.
The original LV2 state extension required that run() is suspended during
restore(). Ardour violates this rule, which can lead to crashes and
other issues.
The state extension has been updated to allow restoring state in a
thread-safe way by using the worker to enqueue state changes. This
commit supports that new specification, i.e. supports dropout-free state
restoration properly.
However, the bug with old plugins that do not use this facility is still
not fixed.
Pass current (latency compensated) cycle times to plugin.
This fixes time-reporting to plugins and also fixes automation
and when bouncing (the session->transport* is not valid) etc.
Allow to re-use Midi buffers for GUI communication. Honor
resize-port extension for all Atom Sequence buffers.
(following example of http://lv2plug.in/book/#_sampler)
This really needs to be fixed on a higher level.
e.g Pluin::connect_and_run() needs to be passed the current time identical to
PluginInsert::connect_and_run()
(n_samples = 64 but Ardour sends midi-buffer with an event at 960)
some guesses as to why:
- split cycle for looping (nominal: 1024, cycle split:64)
- plugin uses _session.transport_frame() directly :(
(not latency compensated offset or looped position)
- "offset" is not taken into account for midi buffers
- tempo/metric change (metric iterator is wrong after loop)
