Bug 68573

Summary:	FORMATTING:Underline enhancement
Product:	LibreOffice	Reporter:	Abdulaziz Ayed <aalayed>
Component:	Presentation	Assignee:	Not Assigned <libreoffice-bugs>
Status:	NEW ---	QA Contact:
Severity:	normal
Priority:	medium	CC:	aalayed, dr.khaled.hosny
Version:	Inherited From OOo
Hardware:	All
OS:	All
See Also:	https://bugs.freedesktop.org/show_bug.cgi?id=35907 https://bugs.freedesktop.org/show_bug.cgi?id=80724
Whiteboard:
i915 platform:		i915 features:
Attachments:	screenshot TestDocument ODPs and screenshots showing underlining of various characters/fonts under v3304 and v4132.

Description Abdulaziz Ayed 2013-08-26 12:54:49 UTC

There is a problem when you write in slide with mixed characters (RTL+LTR)
with underlined fonts.
I think the reason is height of font and also because of (especially in impress)
the text node. as I thought, every group of characters of same language was taken as text node so it has own underline. so, when you write mixed characters that means every group of characters from one language  will represent text node with its underline. all that with a reason of different hieght.

I hope I am right with this thought.

Comment 1 Abdulaziz Ayed 2013-08-26 12:56:40 UTC

Created attachment 84648 [details]
screenshot

Comment 2 Abdulaziz Ayed 2013-08-26 12:57:14 UTC

Created attachment 84649 [details]
TestDocument

Comment 3 Owen Genat 2013-12-21 12:08:04 UTC

Created attachment 91081 [details]
ODPs and screenshots showing underlining of various characters/fonts under v3304 and v4132.

I am not sure this is a bug or if it can be fixed in LO as it would appear to be a font metric related issue. The provided example had the Arabic text set in DejaVu Sans and the English text set in Abyssinica SIL. I don't have the second font installed so the underline displayed identically for both pieces of text (refer screenshot).

I have created two additional examples under Ubuntu 10.04 x86_64 using:

- v3.3.0.4 OOO330m19 Build: 6
- v4.1.3.2 Build ID: 70feb7d99726f064edab4605a8ab840c50ec57a

... each with Latin, Cyrillic, Greek, Hindi, Chinese, Japanese, Hebrew, and Arabic characters. The v3.3.0.4 example uses these fonts:

- Arial for Latin, Cyrillic, and Greek.
- Lohit Hindi for Hindi, Hebrew, and Arabic.
- SimSun for Chinese and Japanese.

The v4.1.3.2 example uses the same fonts except:

- Linux Libertine G for Latin, Cyrillic, and Greek.

A screenshot of what I see here in each case is included. In both examples the same fonts render the underline uniformly, irrespective of characters.

Comment 4 Owen Genat 2013-12-21 12:18:15 UTC

Component set to Presentation. As per comment #3 Version set to Inherited From OOo.

Comment 5 Owen Genat 2013-12-21 12:23:09 UTC

Adding Khaled Hosny to CC list, to hopefully provide some insight into whether this is an issue LO can fix or not (and get this bug confirmed if it is possible to fix).

Comment 6 Khaled Hosny 2013-12-21 22:18:47 UTC

Currently the position and thickness of underline, overlines etc. is font dependant as LibreOffice computes it from font metrics (though fonts can specify some of those values, we don’t use it, but this is a different issue). So when different fonts are used, you can end up with different line position and thickness.

I’m not sure how this can be fixed since there is probably some good reasons to make this font dependant, but I guess one way is to make this configurable so the user can override it, like we do with superscript size and position, for example.

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