In a previous PR, I introduced an optimization that used
`copy_texture_to_texture` to copy directly from a BitmapData GPU
texture to a Stage3D GPU texture.
Unfortunately, this optimization is incorrect. A BitmapData GPU
texture can be modified at any time by normal AVM2 code - in
particular, in might be modified before we submit the encoded
`copy_texture_to_texture` command. This shows up in Sniper Team,
which re-uses BitmapData objects for multiple distinct textures.
The previous 'optimization' resulted in the wrong BitmapData contents
getting uploaded to a texture (since it was changed before the copy
command was submitted).
When multisampling is enabled, we should create a new multisampled texture,
and use the existing texture as the resolve buffer. We also need to
call `update_has_depth_texture` to keep our pipeline aware of whether
or not we currently have a depth buffer attached.
Makes progress on #10641 (it has a stack overflow after
this PR, due to an unrelated issue).
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.
This matches the Context3D docs. Calling 'present' swaps
the buffers.
I wasn't certain if we actually need a double-buffered depth
texture, but I included one just to be safe.
Now that most of the complicated Context3D methods have been
implemented, we can simplify the overall design. Instead of queueing
up commands and having `present` execute them in a loop, we
can execute each command immediately. The key insight is that
a `RenderPass` is only needed for `DrawTriangles`, so we don't
have to store it in `Context3D` and deal with complicated lifetime
issues.
The old behavior gave us implicit double-buffering behavior,
since nothing would get rendered until a 'present' call.
Now that a 'drawTriangles' call will immediately submit
a draw command, we need to implement actual double buffering.
This is done in the next commit.
When we receieve a nonzero 'antiAlias' parameter, we create
create a non-multisampled resolve buffer to use with WGPU.
Several tests were already requesting antialiasing, so their
output images are now anti-aliased without any changes to
the tests themselves.
Previously, we were scaling down the source image to fit into
the smaller sourceRect, instead of cropping at the original scale.
This broke the background textures in Fancy Pants World 4 Part 2,
as the scaled-down output image resulted in a smaller rectangle
being returned from 'getColorBoundsRect'
We now crop the image by properly constructing the UV-coordinate
transformation matrix. We were also using the wrong value for the
'destPoint' y coordinate, which I fixed.
This slightly changes the image output of two tests - the new images
now more closely match the Flash output.
Nathan Adams