wgpu requires buffer copy sizes and offsets to be 4-byte aligned.
Unfortunately, ActionScript can perform 2-byte aligned uploads
into an IndexBuffer3D.
To support this, we now keep a copy of the IndexBuffer3D on the CPU.
When performing an upload to the buffer, we round the offset down
and the size up to the nearest 4-byte aligned value. The cpu buffer
is used to fill out the write with existing data, so that we don't
corrupt the contents of the GPU buffer.
To avoid introducing a new RefCell, I've changed IndexBuffer3D
to use a `Box` instead of an `Rc` to store the trait object.
This allows us to pass a mutable reference down to the backend.
Early class construction is tricky - `Object` defines properties
that need to get copied into subclass instance vtables, but `Class`
defines `prototype`, which needs to be copied into the *class* vtable
of `Object`.
To accomplish this, I've split out instance vtable initialization
into a separate `init_instance_vtable`. We call
`object_class.init_instance_vtable` before
`class_class.init_instance_vtable`, but do things in the opposite
order for `into_finished_class` (`class_class.into_finished_class` is
called before `object_class.into_finished_class`)
It's possible to have a DefineSprite tag with multiple frames,
but with a corresponding SymbolClass that directly extends
`Sprite` (and therefore does *not* extend `MovieClip`). When this
happens, Flash Player stops after the first frame.
Doing `super.someNonGetter` gives you back a function object.
We were previously attempting to call normal methods as though
they were getters. Additionally, we were failing to properly
get the property from the superclass vtable.
If a SWF contains multiple DefineFont tags with the same
font name (but different font IDs), the first tag will win
when a font is looked up by *name*. This affects the behavior
of EditText objects, which can have embedded HTML like
`<font face="MyFontName">` which performs a font lookup by name.
This fixes Fancy Pants World 4 Part 3, which contains two
DefineFont3 tags with the name FancyFont. The second font is
missing many glyphs, so using it causes us to be unable to
render the squiggle and life count text.
iwannabethedev