862997 - svg static text on a path has baseline artifacts with hardware acceleration disabled

Status: RESOLVED FIXED

(Core :: SVG, defect)

Description

[johann]

Attachment: artifacts_top.svg

User Agent: Mozilla/5.0 (Windows NT 6.0; rv:20.0) Gecko/20100101 Firefox/20.0 SeaMonkey/2.17.1
Build ID: 20130410205058

Steps to reproduce:

text on a path


Actual results:

artifacts show up at the baseline


Expected results:

no artifacts

Comment 1

[johann]

no other engine displays this behavior.

the artifacts appear to occur as the glyph is being positioned along the path (i.e., lower-left corner). this includes pre-/post-positioning (blank) areas. of course, the text over-lays the artifacts while spaces allow them to be visible.

the path -- from the 'defs' section -- can have the fill/stroke set to whatever or 'none' or omitted and it makes no difference.

Comment 2

[Loic]

Attachment: Screenshot FF20 on Win 7

I tried with FF20 (Win 7) but I'm not sure if I saw artifacts.

Do you see artifacts on my screenshot?

Comment 3

[Loic]

Ok, artifacts are visible with HWA disabled: http://i.imgur.com/LbzmRAX.png

Comment 4

[johann]

HWA on/off as i find the artifacts from windows <= vista SP2:
1.) SM (Firefox/20.0 SeaMonkey/2.17.1): no difference ... visible
2.) FF (20.0.1): no difference ... visible
3.) AVANT (FF 20.0 gecko engine) no difference ... visible

apparently, HWA has nothing to do with this bug before W7. i would be interested to know if HWA-enabled is the W7 default.

Comment 5

[Robert Longson [:longsonr]]

Fortunately this is fixed on trunk if svg.text.css-frames.enabled is set to true.

Comment 6

[johann]

thank you for this info. i am wondering, though, what can be done to play to the vast majority that are not going to be fiddling with 23.0?

as i mentioned in the 862995 bug, this problem seems to be recent. i am by no definition an SVG guru, but i have lightly used it for several years. since i use SM (although mostly for email) and avant (three-engine mode), i always check out things in those engines plus opera. i do not remember having this problem until, maybe, SM 2.14. this might be because SM is gradually loosing its independence as more and more (if not, by now, all) core is being folded into the main gecko branch.

Comment 7

[Loic]

I'm not sure this bug is fixed. I tried Nightly with HWA disabled and artifacts on the baseline are still visible.

Comment 8

[Robert Longson [:longsonr]]

I tried it with HWA disabled on Vista and saw no artifacts which is why I marked it fixed. 

Do you see any difference if you toggle svg.text.css-frames.enabled?

Comment 9

[Loic]

You're right, I had forgotten to enable this new feature.
With svg.text.css-frames.enabled=true and HWA off, no more artifacts. :)

Comment 10

[Robert Longson [:longsonr]]

That flag should be on by default in nightlies now which is why we're marking all the dependent bugs fixed.