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Get SVG masks working for HTML elements under CSS transforms

RESOLVED FIXED in mozilla16

Status

()

Core
SVG
RESOLVED FIXED
5 years ago
5 years ago

People

(Reporter: jwatt, Assigned: jwatt)

Tracking

Trunk
mozilla16
Points:
---

Firefox Tracking Flags

(Not tracked)

Details

Attachments

(1 attachment, 1 obsolete attachment)

(Assignee)

Description

5 years ago
nsSVGMaskFrame::ComputeMaskAlpha doesn't account for transforms that are already applied to the gfxContext that is being painting to. For elements that are under a CSS transform that's scales the element up, this means that it creates surfaces that are too small (or, more to the point, surfaces that don't have enough resolution) when creating the mask pattern it returns. As a result, the more the element is scaled up, the more pixelated the masking becomes.

This isn't generally a problem for SVG, since the transforms aren't accumulated on the gfxMatrix as we descend down the tree. However, when switching to display list painting of SVG, we do accumulate the transforms as we descend the tree, and this bug causes various SVG reftests to fail.
(Assignee)

Comment 1

5 years ago
Created attachment 637318 [details] [diff] [review]
patch
Attachment #637318 - Flags: review?(roc)
Attachment #637318 - Flags: review?(roc) → review+
(Assignee)

Comment 2

5 years ago
Created attachment 637440 [details] [diff] [review]
patch

Actually, that's not right. While falling asleep last night I got to wondering why I could use SetDeviceOffset() at all, and this morning I came up with a test that proves that I shouldn't be. Here's a new patch to fix that, along with that test.
Attachment #637318 - Attachment is obsolete: true
Attachment #637440 - Flags: review?(roc)
Attachment #637440 - Flags: review?(roc) → review+
https://hg.mozilla.org/mozilla-central/rev/59d39ce427e2
Status: ASSIGNED → RESOLVED
Last Resolved: 5 years ago
Resolution: --- → FIXED
Target Milestone: --- → mozilla16
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