Description: With the latest patches from Khaled, LibreOffice writer (almost) correctly exports the justified Arabic text to the PDF formt. On the other hand, on the screen, there are certain glitches that happen when the display zoom is set on 100%. Steps to Reproduce: 1. Open the attachment 169697 [details] from the bug 139627 2. Set the zoom level to 100% from the bottom of the screen Actual Results: Big gaps are visible between the characters Expected Results: These characters should be joined together in the Arabic script. Reproducible: Always User Profile Reset: No Additional Info: Version: 7.5.0.0.alpha0+ (x64) / LibreOffice Community Build ID: f505d8fee149f089090b208db99a7b4107af76e9 CPU threads: 4; OS: Windows 10.0 Build 19044; UI render: Skia/Raster; VCL: win Locale: fa-IR (fa_IR); UI: en-US Calc: threaded
Created attachment 181899 [details] Visible gaps between characters in the display for justified text
Created attachment 181900 [details] Visible gaps between characters in the display for the last line
I just noticed something like this today as well, but I don’t know when this regressed. Can you bibisect?
(In reply to خالد حسني from comment #3) > I just noticed something like this today as well, but I don’t know when this > regressed. Can you bibisect? Yes, I will do a bibisect. In the latest stable, LibreOffice 7.4, I see that in a certain zoom level (75%), this glitch happens. On other zoom levels, the face of the output is different, and their problem is fixed in the latest 7.5 master. Could you please confirm this bug?
(In reply to Hossein from comment #4) > Could you please confirm this bug? I’m unable to reproduce this, but it might be differences between the version of the font (and/or different screen resolution, I’m on a hidpi screen and sometimes issues show up at different zoom levels from what others report). I’m seeing a different issue that may or may not be related to this, that should be fixed with https://gerrit.libreoffice.org/c/core/+/138588.
REPRODUCED STEPS TO FOLLOWED 1. I have open the given attachment and set it pt into 162pt no glitches . 2. And the spacing also following correct while it in full zoom. ENVIRONMENT OS : WINDOWS HOME 10 LIBRE OFFICE VERSION :Version: 7.4.0.3 (x64) / LibreOffice Community
STATUS:REPRODUCED STEPS TO FOLLOWED: 1: Set the zoom level to 100% from the bottom of the screen. 2:I will Testing the Zoom level 100% is( linux mint) is performed good. ENVIRONMENT: OS:LINUX MINT 20.1 CINNAMON VERSION:4.8.5 PROCESSOR:AMD PRO A4-4350B R4.
Created attachment 182857 [details] Example using KacstPen font This example uses KacstPen font from fonts-kacst package on Ubuntu 22.04, and the kashida has two visible problems: 1. The visible gap between multiple kashidas 2. The inconsistency between kashida height and the text Reproduced with the latest LO 7.5 dev master: Version: 7.5.0.0.alpha0+ / LibreOffice Community Build ID: d23b1d0240e8ca4a33fbd4fcd368c4ece7b8866a CPU threads: 8; OS: Linux 5.15; UI render: default; VCL: gtk3 Locale: en-US (en_US.UTF-8); UI: en-US Calc: threaded The KacstPen font can be downloaded from: https://packages.ubuntu.com/jammy/fonts-kacst http://archive.ubuntu.com/ubuntu/pool/main/f/fonts-kacst/fonts-kacst_2.01+mry.orig.tar.bz2
Created attachment 182858 [details] Example using KacstPen font (PNG screenshot from screen) This is a screenshot from the display at 100% zoom. Gaps are visible between kashidas. Also, the incorrect height/vertical position of the kashidas can be seen.
Created attachment 182859 [details] Example using KacstPen font (PDF) This is the PDF output from the above example. The horizontal and vertical problems with kashidas are visible in the PDF output.
@Khaled: The problem is easier to reproduce with with the KacstPen font. Could you please take a look?
Created attachment 182860 [details] Screenshot showing kashida glyph outlines. (In reply to Hossein from comment #8) > Created attachment 182857 [details] > Example using KacstPen font > > This example uses KacstPen font from fonts-kacst package on Ubuntu 22.04, > and the kashida has two visible problems: > > 1. The visible gap between multiple kashidas > 2. The inconsistency between kashida height and the text > > Reproduced with the latest LO 7.5 dev master: > > Version: 7.5.0.0.alpha0+ / LibreOffice Community > Build ID: d23b1d0240e8ca4a33fbd4fcd368c4ece7b8866a > CPU threads: 8; OS: Linux 5.15; UI render: default; VCL: gtk3 > Locale: en-US (en_US.UTF-8); UI: en-US > Calc: threaded > > The KacstPen font can be downloaded from: > https://packages.ubuntu.com/jammy/fonts-kacst > http://archive.ubuntu.com/ubuntu/pool/main/f/fonts-kacst/fonts-kacst_2. > 01+mry.orig.tar.bz2 Please open different bug reports for different issues. This is badly drawn font. The kasida glyph goes below the basline but other glyphs don’t, and does not have enough overlap so when rendered at low resolution gaps can be visible. Compare how low the lower line of the kashida rectangle compared the glyph next to it, and how the overlapping part on the left is to small compared to the other glyph.
(In reply to خالد حسني from comment #12) > Please open different bug reports for different issues. > > This is badly drawn font. The kasida glyph goes below the basline but other > glyphs don’t, and does not have enough overlap so when rendered at low > resolution gaps can be visible. > > Compare how low the lower line of the kashida rectangle compared the glyph > next to it, and how the overlapping part on the left is to small compared to > the other glyph. Thanks for the explanation! But, I think this font actually reveals the fact that in different zoom levels, the amount of overlap between adjacent kashidas differs slightly, because of rounding or any other reason. When I zoom in and out, the gap between kashida and the adjacent character remains, but the gap between adjacent kashidas goes away. I think this can be helpful in debugging the problem that is discussed here.
(In reply to Hossein from comment #13) > When I zoom in and out, the gap between kashida and the adjacent character > remains, but the gap between adjacent kashidas goes away. > > I think this can be helpful in debugging the problem that is discussed here. May be, but I’m yet to understand ho the new resolution independent positioning works and why it is not preventing these rounding errors.
So, should this bug be re-titled to be about this specific font? Some set of fonts? Or is it actually general?
What is the status here, is this issue still reproducible, if so can we have instructions to reproduce it with a font other than KacstPen?
Created attachment 188300 [details] Visible gaps in the display for justified text with DecoType Naskh font (In reply to خالد حسني from comment #16) > What is the status here, is this issue still reproducible, if so can we have > instructions to reproduce it with a font other than KacstPen? I can still reproduce it with some fonts other than Kacst*. For example, with "DecoType Naskh *". See the attachment.
Created attachment 188301 [details] Visible gaps in the display for justified text with DecoType Naskh font (PDF) Visible gaps in the PDF created with LO 24.2 dev master: Version: 24.2.0.0.alpha0+ (X86_64) / LibreOffice Community Build ID: 7db3c6b25a8c57beab7dae4e0e1497e7b06f3662 CPU threads: 20; OS: Windows 10.0 Build 22621; UI render: Skia/Vulkan; VCL: win Locale: en-US (en_DE); UI: en-US Calc: CL threaded
[Automated Action] NeedInfo-To-Unconfirmed
Hossein, what about other LO modules? Are we sure this doesn't happen in Impress? In Calc?
As explained in comment 12, the KacstPen reproducer is invalid due to font bugs. The other examples are valid. However, the issue is no longer present in the master branch. Bisect shows this bug was already fixed by the following commit: commit 9d9e3b439883c3c315501f56bb613e080863db64 (HEAD) Author: Khaled Hosny <khaled@libreoffice.org> Date: Mon Jul 17 17:21:34 2023 +0300 tdf#156211: Don’t round Kashida width when doing subpixel positioning