1053210 - svg antialiasing glitch at varying scales

Status: NEW

(Core :: SVG, defect)

Description

[Rexx Magnus]

Attachment: bad-antialiasing.png

User Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:31.0) Gecko/20100101 Firefox/31.0 (Beta/Release)
Build ID: 20140716183446

Steps to reproduce:

I have an svg set as the background of a table cell, the svg width and height are set to 100% with preserveAspectRatio="xMidyMid meet" (also does the same without these parameters). The background-size is 2rem 2rem;
The page is scaled using rems, initially with the font size at 62.5%, but then reduced to less. At 62.5% (full size of my design) the svg looks fine, but sizes smaller than this, the antialising becomes inaccurate.


Actual results:

Scaling the page down by reducing the base font size to less than 62.5% results in glitches in the antialiasing. See attached image. 
image contains a small (glitchy) version, a slightly less glitchy version at a larger scale, and then the version at the 62.% font-size that renders accurately.


Expected results:

SVG should scale down smoothly and uniformly, without parts of lines missing or being smudged.

Comment 1

[Loic]

Please, could you attach the svg to the bug.

Comment 2

[Rexx Magnus]

Attachment: Smiley face svg

Attached the smiley face svg as shown in screenshot

Comment 3

[Rexx Magnus]

Attachment: Email icon

Email icon as shown in screenshot

Comment 4

[(mostly gone) XtC4UaLL [:xtc4uall]]

Can you provide/attach a reduced testcase using the already attached svg files?

Comment 5

[Rexx Magnus]

Attachment: A in circle svg for test case

This is a Circled A svg for use in the test case

Comment 6

[Rexx Magnus]

Attachment: Test case html (needs the icon-action-white.svg referenced)

Test case references icon-action-white.svg

Comment 7

[Rexx Magnus]

Attachment: Test case screenshot

Screenshot of test case showing badly antialiased svg background image. Firefox 31, windows 7-64bit.

Comment 8

[Rexx Magnus]

(In reply to XtC4UaLL [:xtc4uall] from comment #4)
> Can you provide/attach a reduced testcase using the already attached svg
> files?

Test case added in comments.

Comment 9

[Loic]

Attachment: 1053210.html (full testcase)

Comment 10

[(mostly gone) XtC4UaLL [:xtc4uall]]

Thanks. I can repro this back to Firefox 4. HWA on/off makes no difference (Windows 7).
FWIW, MSIE 11 faces the same issue.