1229982 - Shadow of decoration is not drawn when shadow blur is applied if text is higher than the baseline

Status: NEW

(Core :: Layout: Text and Fonts, defect)

Description

[Xidorn Quan [:xidorn] UTC+11]

Attachment: testcase

See the attachment.

When there is any shadow blur, the shadow of decoration may not be drawn properly, when text has not intersection with the decoration line. This also affects text emphasis marks because text emphasis marks never have intersection with the original text.

Comment 1

[Tommy Kuo (away forever...)]

This issue also happens with overline and subscript.

Comment 2

[Tommy Kuo (away forever...)]

Attachment: testcase

Add the case with overline and subscript.

Comment 3

[Tommy Kuo (away forever...)]

I try to expand the height of shadowRect[1] by 3 times, and the shadow of underline is shown. But the overline is still missing.

[1]: http://searchfox.org/mozilla-central/source/layout/generic/nsTextFrame.cpp#6205-6208

Comment 4

[Tommy Kuo (away forever...)]

Hi Xidon, do you know where is the code to calculate the position of decoration line? I think we try to get the position of decoration line first to create a larger draw target. And I'm also interested in the framePt[1]. What is it mean?

[1]: http://searchfox.org/mozilla-central/source/layout/generic/nsTextFrame.h#402

Comment 5

[Tommy Kuo (away forever...)]

s/What is it mean/What does it mean

Comment 6

[Xidorn Quan [:xidorn] UTC+11]

(In reply to Tommy Kuo [:KuoE0] from comment #4)
> Hi Xidon, do you know where is the code to calculate the position of
> decoration line?

The calculation code is in nsTextFrame::GetTextDecorations.

> And I'm also interested in the framePt[1]. What is it mean?

IIRC, framePt is the start point of the baseline of the text, but I could be wrong.