Is there a solution for vertical kerning in Arabic script?

21

The lookup flag controls what glyph stays on the baseline. Glyphs sets RTL flag by default for RTL glyphs so the rightmost glyph stays on the baseline, without this flag the leftmost glyph stays on the baseline (which is the desired behavior here), but AFAIK Glyphs has no way to change the lookup flag for cursive anchors.

23

In fact in arabic script we need vertical kerning but our friends in glyphs denying this

24

I’m not denying it. I would never do that. I might be a bit slow understanding and adapting in some cases.

We did work on this together and I implemented it some time ago (in Nov 23). You can disable the lookup flag by adding a “.LTR” suffix to the anchor name. So in this case, use “exit.LTR” and “entry.LTR”. It might not be the most fitting terminology (and I’m open for suggestions to improve this).

25

I missed that you already implemented it. That would be a better solution for the OP issue.

26

Is this correct

# Automatic Code
	pos waw-ar lam-ar' < 0 $N 0 0>;
	pos @Re @Re' < 0 $N 0 0>;

I have 2 masters, in light master N=0 and bold master N=80

I see the correct result in Text Preview but when I exported the font it did not work
If instead of $N I put a number it works, but the number applies in both masters

27

Where?

28

Photoshop - Indesign - Illustrator - https://fontgauntlet.com

29

The number tokens are not supported in variable fonts, yet.

30

I’m totally confused, that’s means I can’t defined vertical kerning. What can I do for vertical kerning now? If one day decide to activate this feature, please do it like left and right kerning and adjustable with up and down arrow keys. You don’t know how much vertical kerning help in Arabic scripts

31

At least if it possible update #exit and #entry anchor.

Untitled-1 copy
Untitled-1 copy1890×1213 160 KB

32

you can. But you need to write the variable GPOS: Variable GPOS — Glyphs Handbook

33

Is it correct?

pos waw-ar lam-ar' <0 0 0 0
	(wght:1000) 0 80 0 0
	> waw-ar;

For light master number is 0 and for bold master is 80. Does the number interpolate between masters? Correct?

34

And what about this? is it possible?

35

To build a curs feature, you need to remove the # prefix from the anchor name (adding any char before the “exit/entry” is a way to avoid the anchor in the curs feature).

For Arabic, the cursive attachment is usually applied in a way that the last attached glyph is anchored on the baseline. That is not what you need here. But you can switch the anchor into LTR mode (where the rightmost glyphs is anchored to the baseline by adding a “.LTR” suffix.

36

Screen Shot 2024-10-05 at 03.15.35
Screen Shot 2024-10-05 at 03.15.35892×784 37 KB

If I understand you correctly, you mean something like this, yes?
If yes, that’s not correct, first Reh is shifted down, zain and meem are at base line
But I want ‘Reh’ to be in its place, ‘Zain’ shifted up, and ‘Meem’ to be in its place.

37

In this case I want just zain move up.
Reh and meem must be in the place

38

Works for me. The preview in Glyphs is wrong, but in the final font, it is correct.

Bildschirmfoto 2024-10-05 um 10.20.22

Here is the sample file:
Exit-LTR.glyphs (28.2 KB)

1 Like
39

YES. FINALLY :heart_eyes:

40

Is this something that can be updated? Can I expect it?

41

That is complicated …