Changing the Order of Precedence of OpenType Features

[Bhikkhu Pesala]

I am sure that I used to be able to change the order by using the Up and Down arrows in the OpenType Designer.

In 9.1, they no longer have any effect. Has something changed that prevents this, or is there another way to do it? Suppose that I want Tabular Figures to be used if both Tnum and Onum are enabled?

Changing Order of Precedence.png (157.68 KiB) Viewed 11552 times

[MikeW]

Hmm. I thought so too. Now only the lookups can move up/down.

[Bhikkhu Pesala]

The features can be moved in the scripts, not where they're listed above the lookups, where they always appear in alphabetical order.

[Erwin Denissen]

Has something changed that prevents this, or is there another way to do it? Suppose that I want Tabular Figures to be used if both Tnum and Onum are enabled?

Regardless of the feature order, the lookup order is important.

So if you want Tabular Figures to be used if both Tnum and Onum are enabled, make sure the TabularFigures lookup is above the OldStyleFigures in the lookup list.

See the result:

LookupOrder.png (120.17 KiB) Viewed 11547 times

[Bhikkhu Pesala]

That's working for Balava, but not for OpenSans.

[Erwin Denissen]

It should be, as this is the only way as far as I know.

OpenSans contains two lookups in onum as well as two lookups in tnum. What is not working?

[Bhikkhu Pesala]

I noticed the pairs of lookups and moved both of them, and tried moving the lookups in the Moldavian and Romanian scripts too, but I still cannot get Tnum to override Onum whatever I do, if they are both enabled. There's a Pnum feature too, and that won't override Onum either.

Here is my modified version.

[Erwin Denissen]

I find the substitutions rather confusing. Maybe they didn't work the way you think they should work.

[Bhikkhu Pesala]

The lnum, onum, pnum, and tnum features were already in the font when I started work on it to added ordn, ornm, and frac.

I am easily confused. I will look at some of my older fonts, and see if I can sort out a system that works how I want.

At least the up and down arrows are working as intended to reorder the lookups.

[Erwin Denissen]

Since the regular digits in OpenSans are already monospaced, the TabularFigures are a little different than usual.

From what I understand; In case both onum and tnum are enabled and TabularFigures comes after OldstyleFigures, the TabularFigures undo what OldstyleFigures did. If the order is different, then TabularFigures is doing nothing, and then OldstyleFigures does its work.