Help with Ignore please

1

Hello :slight_smile:
I don’t use Ignore statements very often, so I’m not really sure what I’m doing. I looked at the OpenType cookbook and couldn’t find quite this example.

I want to make a ligature of three characters except following a couple of base consonants, where things need to be moved around a bit differently.

Here’s what I have in the code now:

lookup burmeseMedialLigs {
	lookupflag 0 UseMarkFilteringSet @myWaMedialHaMedial;
	ignore sub [myJha myRa] myYaMedial' myWaMedial' myHaMedial';
		sub myYaMedial myWaMedial myHaMedial by myYaMedial_myWaMedial_myHaMedial;
		} burmeseMedialLigs;

I need the MarkFilteringSet as there could potentially be other irrelevant marks above the base, stored between the base and the medials. The problem is, I can’t compile this, so there must be something wrong with my ignore statement. How do I stop the ligature from forming after myJha and myRa?

2

I didn’t tried this but can you try the ignore without the tick marks?

3

Yes I tried that too, it won’t compile :frowning:

EDIT: it says Error: “Lookup type different from previous rules in this lookup block” in Feature calt in line: 14

4

that might be because you have an class in the ignore and a simple ligature substitution in the next line. Either have two ignores or use classes (with one glyph) in the ligature (if that even works).

5

You mean to have the myJha and myRa in separate lines? I tried that already too.

EDIT: adding the ticks in the ‘sub’ line works, it seems adding the ticks to the ignore means they have to be added everywhere in that lookup:

lookup burmeseMedialLigs {
lookupflag 0 UseMarkFilteringSet @myWaMedialHaMedial;
	ignore sub [myJha myRa] myYaMedial' myWaMedial' myHaMedial';
		sub myYaMedial' myWaMedial' myHaMedial' by myYaMedial_myWaMedial_myHaMedial;
		} burmeseMedialLigs;

I now have a different problem, though. The medial Ya is a spacing letter, but the medial Wa is a mark that needs to attach to the base. It can’t do that now, since it’s stored after the medial Ya. Is there any way to tell a mark which base to attach to?

6

Correct.

1 Like
7

Is contextual decomposition not allowed? I can do:

sub myYaMedial_myWaMedial by myWaMedial myYaMedial; ## to reorder the glyphs

but I can’t do:

sub myJha myYaMedial_myWaMedial’ by myWaMedial myYaMedial;

As soon as I put a tick on the thing to be decomposed it stops working. I can do it with a chained lookup but just curious why this doesn’t work.

8

You need to decompose the line into a separate lookup:

lookup myYaMedial {
    sub myYaMedial_myWaMedial by myWaMedial myYaMedial;
} myYaMedial;

sub myJha myYaMedial_myWaMedial’ lookup myYaMedial;

something like this, the lookup needs to go to the prefix
(not tested, have written that in the browser)

1 Like
9

Yes, that’s precisely what I meant by ‘chained lookup’, it works fine. But I’m curious why it needs to be broken rather than just a one-line contextual decomposition.

10

That seems to be a limitation of makeOTF. The spec suggests that you can do it inline but makeOTF doesn’t like it.

2 Likes
11

Thanks, glad it’s not just me who found it strange. Will remember for next time :slight_smile: