Bug 7450

Created attachment 6156 [details]
image shows the bug

On Wed, 05 Jul 2006 22:07:42 -0400, Joe Smith wrote:

> much prefer the original default face that came with Fedora 5
> (Luxi?). My eyesight is not what it used to be and I find the Dejavu
> fonts very much less readable (seems mostly spacing issues: too
> "cramped" too "lumpy"). Sorry I can't be any more specific.

Ralf Ertzinger wrote:

One occassion where I noted this is the combination of T with a
smaller letter following (Ta or To, for example). The smaller letter
is very close to the T. I used Vera before, and it hat no such
issue.

I wrote and Ben Laenen replied

> + a few people find some letters are too close compared with vera. I
> mostly agree with them and I seem to remember the problem was
> discussed before on the list, with some agreement the new layout is
> too tight. Is it worth something if I make them list all the problem
> letter combos ? (the usual Ta  To, Fi, Af) ?

this is a known issue, and it will be addressed in future. Maybe when 
Denis will transform the kern pairs into kern classes.

*** Bug 7425 has been marked as a duplicate of this bug. ***

De:       "Steven Stern" <subscribed-lists at sterndata dot com>

Also, as I type the word "monospace", the "m" touches the "o".

I think this is a serious issue and should be addressed with priority, not
"sometime in the future". It is a bit disappointing to find such obvious 
issues in a font for which you made heavy propaganda to become the default
in Fedora...

Created attachment 6322 [details] [review]
widening T+ short lowercase kerning pair

Here's a patch that tries to fix the kerning by dividing the kerning values for
pairs Ta, Tc, Te, To, Ts, Tw, Ty by half and setting kerning value of Ti to
zero.

Let me know if this is good.

Keenan, do you think we should adjust the kerning pairs of V?

Created attachment 6324 [details]
testing kerning before 6322 (last 2 lines are Bitstream Vera Sans)

Screenshot testing kerning with current DejaVu Sans Book, last 2 lines are
Bitstream Vera Sans

Created attachment 6325 [details]
testing kerning with 6322 (last 2 lines are Bitstream Vera Sans)

Screenshot testing kerning with modified DejaVu Sans Book, last 2 lines are
Bitstream Vera Sans

Created attachment 6326 [details]
qt4 vs pango at tiny sizes

weird, I get different results in Gedit (pango) or Textedit (qt4)

Denis, we had the overkerning issue previously too, right? And DejaVu worked
around it.  I'll see if I can fix it in Pango, but it may not be as quick fix as
needed to get into Pango 1.14.

Denis, I have the exact same result with Qt4 as with Pango (including the T 
and e touching each other in the small size from your last screenshot 6326).

Behdad, this isn't the Pango overkerning bug that was a severe problem several 
months ago. This is about the kerning defined in DejaVu, which is too tight.

Ah ok.  The last attachment looked so bad that I assumed it's exposing the
overkerning problem in Pango.

*** Bug 7926 has been marked as a duplicate of this bug. ***

The Hardware field for this bug should probably be "All".  I'm seeing this on an ARM-architecture embedded machine using DejaVu Sans version 2.25.

For what it's worth, I turned off hinting and autohinting at all sizes, and the issue is visibly better, though still not perfect.

On comment #8: Please also consider "T." (like in "The name is MFT. If you ...")