This allows clients to obtain the extras strings for the asset and
for individual nodes. Note that extras for buffer views, accessors, etc
are not supported, although C++ clients can access the raw cgltf data
directly if they need to.
Tested in Android Studio by starting sample-gltf-viewer and typing the
following into the debugger:
modelViewer.asset!!.getFirstEntityByName("Drone_Body")
modelViewer.asset!!.getEntitiesByName("Drone_Body")
modelViewer.asset!!.getEntitiesByPrefix("Drone")
Tested locally by hacking gltf-viewer on Android, added the following
lines to MainActivity:
```kotlin
for (mat in modelViewer.asset!!.materialInstances) {
Log.d("gltf-viewer", mat.name)
}
```
This feature adds one new method to `FilamentAsset` and uses it in our
Kotlin, JavaScript, and C++ helpers:
utils::Entity popRenderable() noexcept;
This pops a ready renderable off an internal queue, or returns 0 if no
renderables have become ready. It provides a simple way for clients to
gradually add renderables to the scene as they become ready. Previously
clients could only get the entire list of entities, regardless of
whether they had Renderable components or complete textures.
To facilitate this feature, this PR adds a new internal-only class to
gltfio called `DependencyGraph`, which is a temporary object used for
bookkeeping during the asynchronous load.
`DependencyGraph` discovers ready-to-render entities by tracking the
textures that each entity depends on. This is a graph because
renderables connect to a set of material instances, which in turn
connect to a set of parameter names, which in turn connect to a set of
texture objects. These relationships are not easily inspectable using
the Filament API or ECS.
Add bindings for releaseSourceAsset() and fix a double-free issue.
According to the Android Studio profiler, this makes Java memory usage
go from 18.6 MB to 6.5 MB.
For now this uses gltfio in the ubershader configuration in order
to avoid the filamat dependency. Note that we have not yet done a size
analysis of the `gltfio_core` library.
New Kotlin-based sample app is forthcoming.
