Combining Marks

I have created combining diacritical marks (CDM) which i want to place sometimes above one letter and sometimes above and between two or more letters. The anchors over single letter glyphs I have no problem with. But I am having difficulty in working out how to place anchors so that I can place the CDM between two letters.

I tried creating 2-letter glyphs by adding glyph (‘a_e’ for example). But once I named it (‘ae0’) set the anchor and attempted to combine it with the CDM (‘ae0_gravetonecomb’) I am presented with an empty glyph box. On exporting to InDesign the CDM did not combine with the base.

When, instead of creating the glyph I edited the ‘æ’ glyph (UNI00E6) to appear as ‘ae’ and added an anchor everything worked fine. What am I missing when creating the glyphs myself?

Not sure what you mean, but:

  1. ae is a single letter, not two letters.
  2. To place something between letters, you do not need anchors, you just type it in the order.
  3. ‘ae0_gravetonecomb’ would not be a mark, but a ligature of a glyph called ae0 (which does not exist) and the combing gravetone.

Its best if I explain the points you gave in reverse order:

  1. I did not mean that ‘ae0_gravetonecomb’ is a mark. ae0 does exist. It is a ligature I created by adding glyph “a_e” and then renaming it ae0. I then attempted to combine it with gravetonecomb (hence ae0_gravetonecomb) but this failed giving empty glyph box called ae0_gravetonecomb.001

  2. If I type the CDM after the first letter (here ‘a’) it will align itself to the anchor of the ‘a’ not to the anchor between the letters in the ‘ae’ ligature which is what I require.

  3. I understand that the character called ae is a single letter ‘æ’, but i edited it, deleting it and pasted in ''ae" which I copied from Adding glyph ‘a_e’ in order to see if I could achieve my aim which I did.

Given that it did not work when I created the ‘ae’ ligature but it did when I edited the standard ae glyph (deleting the ‘æ’ and pasting in ‘ae’), I imagine there must be something wrong with the way I created/named the ligature. Can you think what?

(PS. for some reason my zeros are being converted by the forum editor to these ‘o’)

I still do not understand what you want to achieve and why. Why would you want to rename an a_e ligature to ae0? What is ae0 supposed to be? A ligature? How is one supposed to access ae0 in InDesign? Why not name it a_e if it is supposed to be an a-e ligature?

And why make a ligature in the first place if you want something to go between them? Why not type a, followed by grave, followed by e if that is what you want?

Combining accents like gravetonecomb, by their very definition, combine with the one letter typed before them. If you want an accent by itself, not connecting to a letter, then what you want is a non-combining, spacing accent, like grave.

There are, however, some accents that, technically, go between letters, namely accents that span two letters, like tildedoublecomb, a tilde that is on top the letters typed immediately before and after.

Can you post a sketch of how it should look at the end?

@ mekkablue
I rename the ligature so I could treat it as a single glyph and add an anchor that wouldn’t be treated as an anchor relating to one of the letters.
I want the CDM to sometimes go above letters and sometimes go above & between them. I access these ligatures in Indesign either through the character/glyph viewer.
Regarding accents like tildedoublecomb- can I create these in glyphs? If so , how?

@ GeorgSeifert
i uploaded 2 images.
a_e_gravetonecomb shows the CDMs position above the e.
ae_gravetonecomb.001 shows the CDM correctly above and between the letters (there is an anchor @418,454. )
I

Thanks for your help guys.

Can you tell us why?

Its for a linguistics project I’m undertaking.

And what is the ‘accent in the middle’ supposed to mean, semantically? This is important if you want to find a solution that works Unicode-wise.

Is it supposed to be one accent for both letters, i.e. marking a diphthong? Then, what you want is (a) no ligature and (b) a double diacritic, that is typed between the letters: letter1-doublediacritic-letter2.

a: You cannot have a ligature, because this is just a replacement on the glyph level, but a combining mark is one character that connects to the one character preceding it. Trying to trick a layout engine into a glyph/character confusion is not a good idea. Even if you get it to work somewhere, it is likely to be fixed in the next version.

b: There are some double diacritics in the area U+035D to U+0362, but there is no grave double diacritic. You could roll your own, though. That is what the Private Use Area is for. Find a PUA code point, and generate a glyph that refers to that point, e.g. uniE800. Afterwards you can rename it to gravedoublecomb. Draw a wide grave, and set the width to 0, or even “=0”, make sure the grave is extending to both sides. Then, to type it, either use a Unicode Hex Input keyboard (one is preinstalled with OS X, where you hold down Opt and type E, 8, 0, 0, and the character is typed), or you make your own keyboard layout with Ukelele.

Thanks. Will try your suggestions this coming week.

Hi
I have created my diacritics, set their width to zero, and ‘placed’ them in the Private Use Area of Unicode.

It all appears to be working fine except that once exported to another application (excel/InDesign) the gap between letters before and after the diacritic is sometimes affected even though the diacritic is zero width.

Why is this the case and can it be resolved?

Thanks

If the pair that you put the accent in between has keening, it will not be applied if there is anything between.

Is there any way to resolve this? To somehow apply kerning rules to the next character of greater than zero width?

No, unless it is an actual combining mark, which is not the case here.

Is there something I can do to turn it into a combining mark? Or to give it the property of not affecting the kerning.

You could try making an entry for your mark in the GlyphData XML that follows the way double marks are encoded. That way it will be defined as a mark in GDEF.

Could you pls expand on this or direct me to where I could learn how to do this?

Also what do you mean by “double marks”?

https://www.glyphsapp.com/tutorials/roll-your-own-glyph-data

I explained double marks further above (b).