Our AVM2 `SharedObject` support is now *almost* equivalent
to our avm1 `SharedObject` support. We implement serialization
and deserialization for primitives, arrays, and `Object` instances
with local properties. We also implement serialization for `Date`,
but not `Xml` (since our AVM2 `Xml` class is just a stub at the moment).
This is enough to make 'This is the only level too' save level
progress to disk.
Currently, we always serialize to AMF3. When we implement
the `defaultObjectEncoding` and `objectEncoding`, we'll need
to adjust this.
An AVM2 movie can repeatedly remove and add a DisplayObject from/to
a parent. This was causing SolarMax to stop working after advancing
to the next level.
We now check if a BitmapData has been disposed by checking
for a zero width or height (which cannot happen otherwise).
As a result, we no longer need the 'disposed' field on the AVM1
BitmapData object.
* avm2: Implement `BitmapData.draw` for `wgpu` backend
This method requires us to have the ability to render directly to a
texture. Fortunately, the `wgpu` backend already supports this in
the form of `TextureTarget`. However, the rendering code required
some refactoring in order to avoid creating duplicate `wgpu` resources.
The current implementation blocks on copying the pixels back
from the GPU to the CPU, so that we can immediately set them in
the Ruffle `BitmapData`. This is likely very inefficient, but will
work for a first implementation.
In the future, we could explore allowing the CPU image data and GPU
texture to be out of sync, and only synchronized when explicitly
necessary (e.g. on `getPixel` or `setPixel` calls).
* Rename `with_offscreen_backend` to `render_offscreen` and use Bitmap
* Don't panic when backend doesn't implement `render_offscreen`
We already have `&mut self` available whenever we write to it,
and we never made use of the `Clone` impl. As far as I can tell,
we don't have any unimplemented features that would require a `GcCell`.
The stub implementation was breaking code that relied on being
able to set a value for 'mask' and then retrieve it
(which used to work on a dynamic class like `MovieClip`).