1696301 - Tiled clip masks can be incorrectly culled on scaled raster root surfaces

Status: RESOLVED FIXED

(Core :: Graphics: WebRender, defect)

Comment 1

[Glenn Watson [:gw]]

Attachment: Bug 1696301 - Tiled clip masks can be incorrectly culled on scaled raster root surfaces.

The check for which tiles of a clip mask need to be drawn was using
the surface device pixel ratio to calculate a true device position
for the tile. In most cases, this works fine.

However if the device pixel ratio of a surface is different to the
global device pixel ratio (e.g. due to a scale factor being applied
on a surface that establishes a raster root), then the calculations
are incorrect and can result in skipping clip mask tiles that do
need to be rendered for correctness.

Comment 2

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/c7760ee4f8e2
Tiled clip masks can be incorrectly culled on scaled raster root surfaces. r=gfx-reviewers,bradwerth

Comment 3

[Dorel Luca [:dluca]]

https://hg.mozilla.org/mozilla-central/rev/c7760ee4f8e2