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.
Setup for both LibreOffice 6.1 and 5.1: Windows 10 and LibreOfficePortable
User Profile Reset: No
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?
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LibreOffice 5.1 large fonts
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LibreOffice 5.1 small fonts
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LibreOffice 6.1 large fonts
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LibreOffice 6.1 small fonts
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.
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LibreOffice 5.1 sample document and AboutLibreOffice
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LibreOffice 6.1 sample document and AboutLibreOffice
I added two sample documents with the AboutLibreOffice included. Thank you.
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.
Created attachment 148187 [details]
LibreOffice 5.1 cleartype full color aliasing
The LibreOffice 5.1 Cleartype full-color aliasing looks much better onscreen.
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LibreOffice 6.1 grayscale only aliasing
The LibreOffice 6.1 grayscale only aliasing looks a lot more jagged onscreen.
(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?
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?
A general discussion is needed: https://bugs.documentfoundation.org/show_bug.cgi?id=122730
Created attachment 148711 [details]
Somehow OpenGL is forcing font hinting without ClearType enabled. Creating a bit of a blurry experience.
author Tim Eves <email@example.com> 2016-02-23 16:45:21 +0000
committer Tor Lillqvist <firstname.lastname@example.org> 2016-03-14 12:50:59 +0200
commit e45d80f20ff6a05888f92ae942abed67609d5b20 (patch)
parent 2a1b70c4b2d5debf235c088a1e3c71a3457c1af7 (diff)
tdf#97171: Use DirectWrite for OpenGL glyph caching
Created attachment 148712 [details]
Comparison screenshot magnified 300%