uneven character spacing

[Barryd]

I am using Libre office 6.4 on linux mint Lmde.

I noticed that the font spacing between character using Writer in a single line is very uneven depending on where on the page the character is. It is noticeable with fonts like dejavu sans which is my preferred readable font.

Kerning is turned on but it does not seem to have much of an impact on the uneven font spacing.

Is there something I can do to fix this?

This example used font size 10 and 100 percent zoom

The printing does not have the same spacing issues.

[LeroyG]

@Barryd,

Do you say it from what it looks like on the screen, or from a printed paper?

[ajlittoz]

Since your question is clearly related to Writer, retag it to remove common (relevant for a problem “common” to all components Writer, Calc, Impress, Base, Draw and Math) and also libre-writer to replace it with the standardised writer and adding some more specific tag like character-spacing and uneven.

Thus your question is more likely to reach people more able to answer.

[gabix]

Share a sample file.

[LeroyG]

@Barryd,

Please, copy your “answer”, edit your question, and paste it there. Then delete your answer, because it doesn’t solve your question. Thanks.

Leaving your comment as an answer reduces the possibility of other users reading the question.

[LeroyG]

@Barryd,

I tried DejaVu Sans in Calc, Writer, Impress and Draw. And yes, I see differences, but it varies when zoom varies. It seems to me that it has to do with the quality of the screen I am using.
On LibreOffice: 6.3.6.2; OS: Windows 6.1.

[mikekaganski]

Most likely tdf#103322.

[ajlittoz]

@BarryD: you were able to edit your “answer”. Then, follow @LeroyG’s comment. Editing a question is just the same as editing an answer. Transfer the stuff into your question. @LeroyG is right: your question is listed as “answered” in the home page and many contributors won’t bother to check if this is a real solution.

[ajlittoz]

@Barryd: add after your screenshot the properties of the text. You already told it is DejaVu Sans. Which size? What is the zoom factor (bottom right in the status bar)? What is the dpi of your screen?

Have you the same defaults in print? Since the dpi of printers is commonly higher than screen, you’ll need a magnifying glass to tell. Look at the same “damaged” spot as on screen.

[ajlittoz]

Thanks for the reply. What is the dpi of your screen?

I see many irregular spacing around “i”, “liq” being very problematic.

[Barryd]

I am not sure what the DPI is but the screen resolution is 1366 x 768

[ajlittoz]

With 1366x768, I guess this is laptop, probably 15-16". 16:9 aspect ratio. This gives me ~74 dpi, not far for the “historic” density of 72 dpi. Consequently, the screen does not qualify as HiDPI monitor and the renderer does not try to play “smart” to give the nominal size on screen. There is no scaling.

Your text is formatted in a relatively small size (every character does not count a big number of pixels in its width). Since all positioning is computing with integer numbers, a choice must be made when a position is not exactly on a pixel boundary. The position is rounded toward left or right. This was particularly visible in your opopopopop screenshot where “sometimes” the cumulative error caused a character to be brutally offset by one position.

Some renderers (but not the one in LO) try to improve the case with “subpixel technology”, i.e. knowing the order or the RGB stripes, they send colored pixels on the edges, switching of the extreme stripes, resulting in a 1/3 rounding.

[Barryd]

So how do we fix the font spacing in libreoffice then

[ajlittoz]

I’m afraid there is no user-accessible solution. There are numerous complaints (questions) on this site about this integer rounding in the font renderer (Harfbuzz if I’m right).

The only workaround is to play with the zoom factor to find a ratio which minimises the visual nuisance.

[Barryd]

Nope id rather uninstall than try and “fudge the system”