1522758 - Optimize drawing axis aligned clip rectangles into clip masks.

Status: RESOLVED FIXED

(Core :: Graphics: WebRender, enhancement)

Description

[Glenn Watson [:gw]]

When a primitive has a complex transform, we currently (may change in future!) need to draw a clip mask if that primitive is affected by any axis-aligned clips.

However, clip mask drawing is relatively slow in the current form (also may change in future!).

With a small amount of CPU work, for the common case, we can split the clip mask area into tiles and eliminate drawing the clip mask in most of those tiles, where we can establish that the clip mask can't possibly affect that tile.

This can give a very significant GPU performance win on some pages. Even though better solutions probably exist, this is an easy win now that only requires a small amount of code.

Comment 1

[Glenn Watson [:gw]]

Attachment: Bug 1522758 - Optimize drawing axis aligned clip rectangles into clip masks.

Comment 2

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/8e87ea84e5df
Optimize drawing axis aligned clip rectangles into clip masks. r=kvark

Comment 3

[Cristian Brindusan [:cbrindusan]]

https://hg.mozilla.org/mozilla-central/rev/8e87ea84e5df