1042296 - SVG mix-blend-mode doesn't work when combined with clip-path

Status: RESOLVED WORKSFORME

(Core :: SVG, defect, P3)

Description

[Peter Lai]

Attachment: blend-mode-bug.svg

User Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_9_3) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/36.0.1985.125 Safari/537.36

Steps to reproduce:

Open the attached file to view the repro.


Actual results:

When mix-blend-mode is used in conjunction with clip-path, the resulting colors are incorrect.


Expected results:

mix-blend-mode should correctly be applied regardless of whether clip paths are used. (NOTE: the mix-blend-mode experimental flag must be enabled).

Comment 1

[Paul Silaghi, QA [:pauly]]

Confirmed in 34.0a1 (2014-07-24), Win 7 x64

Comment 2

[u459114]

The first patch in bug 1279409 can "partially" fix the bug here. There are still another cause.

Comment 3

[u459114]

The painting result(the content of texture) is correct now. But the composition result of "#top_right" one is not right yet. I would suggest find a developer who is familiar with compositor to do further analysis. Deassign from myself.

Comment 4

[u459114]

Attachment: Screenshot from 2016-10-12 16-29-12.png

Comment 5

[Ethan Lin[:ethlin]]

After study, it's not compositor problem. I printed the layer tree in content and the blend mode of the layer was none.
So I traced back to ProcessDisplayItems. I found that for the wrong case, we create a temp BasicLayerManager and the layer created by nsDisplayBlendMode is contained in this BasicLayerManager. The PaintInactiveLayer result of the temp BasicLayerManager doesn't have the blend effect. The blend operation may be removed in bug 1279409.

Comment 6

[u459114]

Rendering result is not correct when nsDisplayMask contains a nsDisplayBlendMode child.

Comment 7

[Markus Stange [:mstange]]

Why is the blend mode inside the mask? nsIFrame::BuildDisplayListForStackingContext should be creating the blend mode outside the mask.

Comment 8

[u459114]

Attachment: Bug 1042296 - Part 1. Implement ShouldCopyBackground.

Review commit: https://reviewboard.mozilla.org/r/92040/diff/#index_header
See other reviews: https://reviewboard.mozilla.org/r/92040/

Comment 9

[Robert Longson [:longsonr]]

Seems OK now.