Bug 122457 - Worse text rendering in newer versions of LibreOffice (OpenGL)
Summary: Worse text rendering in newer versions of LibreOffice (OpenGL)
Status: UNCONFIRMED
Alias: None
Product: LibreOffice
Classification: Unclassified
Component: Writer (show other bugs)
Version:
(earliest affected)
unspecified
Hardware: All Windows (All)
: medium normal
Assignee: Not Assigned
URL:
Whiteboard:
Keywords: bibisectRequest, regression
Depends on:
Blocks: Font-Rendering
  Show dependency treegraph
 
Reported: 2019-01-04 01:50 UTC by Sam
Modified: 2019-01-28 14:17 UTC (History)
10 users (show)

See Also:
Crash report or crash signature:


Attachments
LibreOffice 5.1 large fonts (50.37 KB, image/png)
2019-01-04 15:20 UTC, Jan-Marek Glogowski
Details
LibreOffice 5.1 small fonts (7.42 KB, image/png)
2019-01-04 15:20 UTC, Jan-Marek Glogowski
Details
LibreOffice 6.1 large fonts (50.58 KB, image/png)
2019-01-04 15:20 UTC, Jan-Marek Glogowski
Details
LibreOffice 6.1 small fonts (6.52 KB, image/png)
2019-01-04 15:21 UTC, Jan-Marek Glogowski
Details
LibreOffice 5.1 sample document and AboutLibreOffice (36.74 KB, application/vnd.oasis.opendocument.text)
2019-01-04 21:27 UTC, Sam
Details
LibreOffice 6.1 sample document and AboutLibreOffice (39.61 KB, application/vnd.oasis.opendocument.text)
2019-01-04 21:27 UTC, Sam
Details
LibreOffice 5.1 cleartype full color aliasing (11.08 KB, image/png)
2019-01-09 23:37 UTC, LibreTraining
Details
LibreOffice 6.1 grayscale only aliasing (11.01 KB, image/png)
2019-01-09 23:39 UTC, LibreTraining
Details
Bibisect log (4.64 KB, text/plain)
2019-01-28 14:16 UTC, Telesto
Details
Comparison screenshot magnified 300% (29.25 KB, image/png)
2019-01-28 14:17 UTC, Telesto
Details

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Description Sam 2019-01-04 01:50:33 UTC
Description:
Hi,

Text rendering is LibreOffice 6.1 is considerably worse than what it was in version 5.1. I did not thoroughly check to see in which version the difference appeared.

Please take a look at the pictures.

https://drive.google.com/drive/folders/1MYfDE-j9Q8eIwc5wG5V5cymZikqYlh13?usp=sharing

Thank you.

Setup for both LibreOffice 6.1 and 5.1: Windows 10 and LibreOfficePortable



Actual Results:
N/A

Expected Results:
N/A


Reproducible: Always


User Profile Reset: No



Additional Info:
Comment 1 V Stuart Foote 2019-01-04 14:27:05 UTC
What rendering were you using?  OpenGL or Default (CPU only, or with Hardware Acceleration)

Also, for your screen clips--is that a Writer file, and at what document zoom did you set when you screen clipped?
Comment 2 Jan-Marek Glogowski 2019-01-04 15:20:09 UTC
Created attachment 148031 [details]
LibreOffice 5.1 large fonts
Comment 3 Jan-Marek Glogowski 2019-01-04 15:20:32 UTC
Created attachment 148032 [details]
LibreOffice 5.1 small fonts
Comment 4 Jan-Marek Glogowski 2019-01-04 15:20:55 UTC
Created attachment 148033 [details]
LibreOffice 6.1 large fonts
Comment 5 Jan-Marek Glogowski 2019-01-04 15:21:18 UTC
Created attachment 148034 [details]
LibreOffice 6.1 small fonts
Comment 6 Jan-Marek Glogowski 2019-01-04 15:28:15 UTC
I just copied the images to the bug report.
It looks like Antialiasing is missing.

Please copy the info from "About LibreOffice" dialog.
And add your example documents.
Comment 7 Sam 2019-01-04 21:27:30 UTC
Created attachment 148049 [details]
LibreOffice 5.1 sample document and AboutLibreOffice
Comment 8 Sam 2019-01-04 21:27:52 UTC
Created attachment 148050 [details]
LibreOffice 6.1 sample document and AboutLibreOffice
Comment 9 Sam 2019-01-04 21:28:27 UTC
I added two sample documents with the AboutLibreOffice included. Thank you.
Comment 10 LibreTraining 2019-01-09 23:35:01 UTC
The screen rendering went off a cliff, on Windows at least, with LO v5.3.
This is when the rendering engine was changed.

On Windows this caused the aliasing to go from the full-color Cleartype aliasing to some kind of lesser grayscale-only aliasing.

So on Windows the move to Harfbuzz (BarfHuzz) was a step backwards.

Below I have attached zoomed-in screenshots of your small images.

In the first one from LO v5.1 you can see the colors in the aliasing.

In the second one from LO v6.1 you can see only grayscale.

There was also apparently some change in how the vertical metrics are rendered.
This is why you see changes in the line heights.

You will also see at smaller sizes the characters appear to jump around and have big gaps between them due to changes in how the hinting is handled.

None of this is documented anywhere that I have found.
You can only discover bits and pieces of what is happening by reviewing multiple bug reports.
I think some people just don't want to talk about it.

From what I have seen there currently are no plans to fix this.
The LO fonts rendering "guru" appears to have abandoned the ship when it sank.

.
Comment 11 LibreTraining 2019-01-09 23:37:37 UTC
Created attachment 148187 [details]
LibreOffice 5.1 cleartype full color aliasing


The LibreOffice 5.1 Cleartype full-color aliasing looks much better onscreen.
Comment 12 LibreTraining 2019-01-09 23:39:32 UTC
Created attachment 148189 [details]
LibreOffice 6.1 grayscale only aliasing


The LibreOffice 6.1 grayscale only aliasing looks a lot more jagged onscreen.
Comment 13 Buovjaga 2019-01-10 19:06:48 UTC
(In reply to LibreTraining from comment #11)
> Created attachment 148187 [details]
> LibreOffice 5.1 cleartype full color aliasing
> 
> 
> The LibreOffice 5.1 Cleartype full-color aliasing looks much better onscreen.

This is what I get with 6.1 and 6.3. Cleartype is on (Win 10). I wonder, why we get different results?
Comment 14 Buovjaga 2019-01-10 19:10:56 UTC
From Sam's sample documents we see in 5.1 he is not using OpenGL and in 6.1 he is (Sam: please next time just select & copy the text from the About window and do not bother to take a screenshot).

LibreTraining: are you using OpenGL or not?
Comment 15 Karsten 2019-01-16 11:05:51 UTC Comment hidden (obsolete)
Comment 16 Telesto 2019-01-28 14:16:27 UTC
Created attachment 148711 [details]
Bibisect log

Somehow OpenGL is forcing font hinting without ClearType enabled. Creating a bit of a blurry experience. 

Bisected to:

author	Tim Eves <tim_eves@sil.org>	2016-02-23 16:45:21 +0000
committer	Tor Lillqvist <tml@collabora.com>	2016-03-14 12:50:59 +0200
commit	e45d80f20ff6a05888f92ae942abed67609d5b20 (patch)
tree	fef594425e80e321d4b6466e228fb4a85c97cac7
parent	2a1b70c4b2d5debf235c088a1e3c71a3457c1af7 (diff)
tdf#97171: Use DirectWrite for OpenGL glyph caching

https://cgit.freedesktop.org/libreoffice/core/commit/?id=e45d80f20ff6a05888f92ae942abed67609d5b20
Comment 17 Telesto 2019-01-28 14:17:35 UTC
Created attachment 148712 [details]
Comparison screenshot magnified 300%