975764 - Add mesh-based transformation support to container layers

Status: RESOLVED INVALID

(Core :: Graphics: Layers, defect)

Description

[Andreas Gal :gal]

This is useful for advanced over-scroll effects as well as the CSS filter effects spec.

Comment 1

[Andreas Gal :gal]

Attachment: API change. Backend support coming separately.

Comment 2

[Andreas Gal :gal]

Note: I am going to switch the internal representation of the meshes to triangle strips with degenerate triangles between each row.

Comment 3

[Andreas Gal :gal]

As indicated in comment 2 a triangle strip is more efficient to represent the meshes. The API will be the same so feel free to give feedback on the API while I test the triangle strip approach.

Comment 4

[Robert O'Callahan (:roc) (email my personal email if necessary)]

Comment on attachment 8380239 [details] [diff] [review]
API change. Backend support coming separately.

Review of attachment 8380239 [details] [diff] [review]:
-----------------------------------------------------------------

Sorry about the delay, somehow I lost the request.

::: gfx/layers/Layers.h
@@ +661,5 @@
> +
> +  const void *VertexBuffer() const;
> +  size_t VertexBufferSize() const;
> +
> +  const void *IndexBuffer() const;

Unclear why these return void*.

@@ +664,5 @@
> +
> +  const void *IndexBuffer() const;
> +  size_t IndexBufferSize() const;
> +
> +  gfx::IntSize GetDimensions() const { return mDim; }

All these members need documentation. especially regarding the sizes and meaning of the buffers.

@@ +1697,5 @@
>     * on this layer.
>     * Returns true if this will use an intermediate surface. This is largely
>     * backend-dependent, but it affects the operation of GetEffectiveOpacity().
>     */
> +  bool UseIntermediateSurface() { return mForceIntermediateSurface || !!mLayerMesh; }

Instead, have ComputeEffectiveTransforms set mForceIntermediateSurface if mLayerMesh is present

@@ +1756,5 @@
>    // The resolution scale inherited from the parent layer. This will already
>    // be part of mTransform.
>    float mInheritedXScale;
>    float mInheritedYScale;
> +  bool mForceIntermediateSurface;

I'm not sure why you renamed this. mUseIntermediateSurface was set iff we decided to use an intermediate surface. I'm not sure why you're changing that.

@@ +1761,3 @@
>    bool mSupportsComponentAlphaChildren;
>    bool mMayHaveReadbackChild;
> +  nsRefPtr<Mesh> mLayerMesh;

Move this up with the other pointers.

Comment 5

[BugBot [:suhaib / :marco/ :calixte]]

The bug assignee didn't login in Bugzilla in the last 7 months, so the assignee is being reset.