Java callbacks are now directly dispatched to their handler, instead
of first going through filament's opportunistic dispatch, reducing
callback latency.
- we were allocating objects with a destructor in the command stream
which is always invalid because there is no guarantee that when
the callback is called, the underlaying memory is still valid
(and it wasn't).
- AutoBuffer move-ctor wasn't moving some of its state, which would
lead to destroying the same ref several times.
Static JNI lookups were causing issues with multiple libraries.
We now do the lookups when we need them as they are effectively
just hashmap lookups and we do them only in places where the
work we need to perform will be much larger than a simple hash
map lookup anyway.
This chane also manually registers filament-utils JNI bindings
to get rid of unnecessary symboles. We should do the same for
other Filament libraries (the symbols are pretty long and
we now have many of them).
Previously, Streams had two modes (native and texid), this adds a third
mode called "acquired", which allows for copy-free synchronized external
textures in OpenGL and paves the way for Vulkan.
The native mode is now deprecated but texid mode needs to stay around
until all clients can be upgraded.
In an early prototype, this functionality was added directly into
Texture but required quite a bit of additional state tracking, so the
Stream API seemed like a better fit.
This API is probably not necessary for Metal due to Metal's shared
ownership semantics.
This has been tested with a new Android sample that will be added in a
subsequent PR.
No need for a proper library, this is just a common location to simplify
JNI bindings in other projects like filamat and gltfio.
There is no need to move the one Java source file (`NioUtils.java`)
since downstream libraries will have a dependency on Filament, and
FindClass should work fine.
