Each render backend keeps track of a stack of BlenModes,
which are pushed and popped by 'core' as we render objects
in the displaay tree. For now, I've just implemented BlendMode.ADD,
which maps directly onto blend mode supported by each backend.
All other blend modes (besides 'NORMAL') will produce a warning
when we try to render using them. This may produce a very large amount
of log output, but it's simpler than emitting each warning only once,
and will help to point developers in the right direction when they
get otherwise inexplicable rendering issues (due to a blend mode
not being implemented).
The wgpu implementation is by far the most complicated, as we need
to construct a `RenderPipeline` for each possible
`(BlendMode, MaskState)`. I haven't been able to find any documentation
about the maximum supported number of (simultaneous) WebGPU render
pipelines - if this becomes an issue, we may need to register them
on-demand when a particular blend mode is requested.
This PR implements the 'DisplayObject.transform' getters/setters,
and most of the getters/setters in the `Transform` class
From testing in FP, it appears that each call to the
'DisplayObject.transform' property produces a new
'Transform' instance, which is permanently tied to the
owner 'DisplayObject'. All of the getters/setters in
`Transform` operate directly on owner `DisplayObject`.
However, note that the `Matrix` and `ColorTransform`
valuse *produced* the getter are plain ActionScript objects,
and have no further tie to the `DisplayObject`.
Using the `DisplayObject.transform` setter results in
values being *copied* from the input `Transform` object.
The input object retains its original owner `DisplayObject`.
Not implemented:
* Transform.concatenatedColorTransform
* Transform.pixelBounds
When a DisplayObject is not a descendant of the stage,
the `concatenatedMatrix` property produces a bizarre matrix:
a scale matrix that the depends on the global state quality.
Any DisplayObject that *is* a descendant of the stage has
a `concatenatedMatrix` that does not depend on the stage quality.
I'm not sure why the behavior occurs - for now, I just manually
mimic the values prdduced by FP. However, these values may indicate
that we need to do some internal scaling based on stage quality values,
and then 'undo' this in certain circumstances when constructing
an ActionScript matrix.
Unfortunately, some of the computed 'concatenatedMatrix' values
are off by f32::EPSILON. This is likely due to us storing some
internal values in pixels rather than twips (the rounding introduced
by round-trip twips conversions could cause this slight difference0.
For now, I've opted to mark these tests as 'approximate'.
To support this, I've extended our test framework to support providing
a regex that matches floating-point values in the output. This allows
us to print out 'Matrix.toString()' and still perform approximate
comparisons between strings of the format
'(a=0, b=0, c=0, d=0, tx=0, ty=0)'
This is the last stub needed for Wonderputt to reach the
main game screen.
As far as I know, ActionScript cannot observe a frame being rendered,
so implementing this method isn't actually necessary for correctness.
The benefit of implementing this would be to make certain animations
appear smoother, since we'll render changes to the scene without
needing to wait for the next frame. However, actually rendering
*immediately* after the event would require some refactoring -
we have a `&mut UpdateContext` while running timers, but we'd need
to bail out and obtain a `&mut Player`.
Many of the class property defintiions were wrong -
instance methods were defined as class properties,
and class properties were defined as instance properties.
This allows Wonderputt to get further (it deliberately assigns
'null' to 'URLRequest.data'). We throw an exception for any other
value, to prevent confusing errors caused by attempting an
unexpected request to a web server with a missig body.
We currently lack the ability to preserve the original
`Value<'gc>` in the error, so we're forced to stringify the error.
This means that only typeless 'catch' blocks will work properly -
however, they're the only kind of 'catch' block that we currently
implement. Implementing support for typed 'catch' blocks will naturally
allow us to preserve the original 'Value<'gc>' in the 'throw'
implementation, since we'll need to switch to a custom `Error<'gc>`
type.
Mike Welsh