Created attachment 140678 [details]
PDF example of behaviour using Scribus for comparison
In Libre Office 5 or 6, (Windows 10 - 64 bits), when I modify the width of some part of a text, using the command " Format ", " character " (width scale in%), it appears that the thickness of characters decrease simultaneously with the width decrease of the text.
In older versions of LibO it was not the case (as far as I can remember)
If I compare the same process operated with Scribus for example, the thickness of the characters is not affected. Example is attached with a sample text on which I apply a contraction of 5 % in Scribus. I would expect to get the same result in LibO.
If I am right, using the version included in Ubuntu 17-10 (32 bits), the thickness of the charactèrs seems to be not affected.
I confirm it, but the Linux result looks worse than Windows in my eyes. The characters blend into each other in an ugly way.
For testers: Format - Character - Position: Scale width.
Comment from Khaled on IRC:
"the directwrite path does not handle asymmetric character scaling, but we should be forcing GDI in this case."
Arch Linux 64-bit
Build ID: 070dbae6b4dc497d6ae898e60203d25b0e608d73
CPU threads: 8; OS: Linux 4.15; UI render: default; VCL: kde4;
Locale: fi-FI (fi_FI.UTF-8); Calc: group
Built on March 17th 2018
Version: 184.108.40.206.alpha0+ (x64)
Build ID: 3677ca53c60304830285233474466de3272ec183
CPU threads: 4; OS: Windows 10.0; UI render: default;
TinderBox: Win-x86_64@42, Branch:master, Time: 2018-03-18_01:31:20
Locale: fi-FI (fi_FI); Calc: group
Code pointer from Khaled, if someone wants to dig into this: https://opengrok.libreoffice.org/xref/core/vcl/win/gdi/winlayout.cxx#417
Created attachment 140682 [details]
Screenshot Linux vs. Windows 10, 80% scaled
Created attachment 140683 [details]
Screenshot Linux vs. Windows 10, 50% scaled
This is the expected behavior and has always been like that AFAIK (bugs in some versions not withstanding). If you want to change the spacing only, set a “Pair Kerning” value.
Thank you for your comments.
I was guided by a previous use of decreasing width percentage to adjust length of part of my text (LibO 3 as far as I can remember)where the things appeared to work as expected.
I will follow the recommandation of Khaled.