This is very ugly so hopefully I can think of a neater way, but now the
response object is just a set of pointers, so we can avoid all copies
and moves on the Wine side.
We do this by using this new `MessageReference<T>` type to avoid copying
our `YaAudioProcessor::Process` struct and the contained `YaProcessData`
object. This is only part of the work, but this redesign lets us keep
the these objects alive on both the plugin and the host side. On the
plugin side, we'll simply serialize the data from the referred to object
without copying it. On the Wine side, we'll write the data to a
persistent thread local object, and then reassign the
`MessageReference<T>` to point to that object. This lets us serialize
'references', thus avoiding potentially expensive allocations. With
these last few changes alone VST3 plugins are already at the same
performance level as our optimized VST2 plugin groups.
I was wondering why I couldn't find the overload for `UniversalTResult`,
and as it turns out we would always use this variant (which
unsurprisingly was the very first overload added). We should of course
have separate overloads for this.
This is in some cases needed to get decent performance in REAPER, as
REAPER seems to query this information (which cannot change without the
plugin requesting a restart) four times per second.
This is a breaking change. Old projects containing VST3 plugins running
through yabridge will no longer work without modifications. I'll write
some scripts to convert the class IDs stored in those project files soon
a migration path.
The UIDs reported by the plugin were apparently wrong, which meant that
the native Linux VST3 version of plugin X and the normal Windows VST3
version of plugin X used different class ideas than the Windows VST3
version of plugin X running through yabridge. Those things are supposed
to be compatible, so we sadly needed to make this change at some point.
This allows presets to contain meta data about file names and the type
of preset.
Even though the docs don't mention that this is also relevant for
`getState()`, we should also implement it there so plugins can write
their own meta data.