We speak about compound glyphs, for example uni1EA4 (Latin Capital Letter A with circumflex and acute).
In some cases the glyph exists as a whole in the font, in other cases the glyph is composed of two glyphs, sometimes with the use of an anchor.
Finally, in some fonts there are, while in others they are absent, the ranges of the glyphs modifier (from slot 688) and combinig (from slot 768).
What is the most functional procedure to create these composite glyphs?
Comments
The only thing worth pointing out here is that combining accent marks are generally more useful than the spacing modifier versions of these accents, and there are numerous combining accents which have no encoded spacing glyphs. So if you're only going to include one of these sets, go with the combining forms.
In a guide online I read:
If you want to have both, it is easy to make one as a set of differently-spaced composites based on the other. (Combining accents are normally non-spacing.)
FontLab VI has a fair bit of automation for this, although I do have to tell it to make anchors on a glyph-by-glyph basis.
For base glyphs, the y-position of the anchor can be deduced from whether it is uppercase or lowercase. The x-position of the anchor will sometimes need manual tweaking, but some simple heuristics can at least get it in the right area, to start.
For combining marks, the anchor position is going to be the same for all of them, anyway. A pref could indicate whether the initial position is relative to x-height or relative to cap-height. Or the app could reasonably deduce this from the marks’ y-positioning.
One major advantage of this is, if I make tweaks later on to glyph widths, whether it is the sidebearings or the marking portions, and move the anchor accordingly, all the composites can get updated automatically. No more “did I remember to update the accented characters after I made that change?”
Also, the benefit of anchors rises depending on the number of accented glyphs one is doing. If only western European accented Latin, it is “nice” but not exceptional. As one gets further into central European and extended Latin, perhaps with polytonic Greek and extended Cyrillic as well, the benefits increase dramatically.
On new designs, this is a huge time saver. I design my base glyphs and marks (combining accents) first, set all the anchors, and, when all is ready, generate all the accented characters in one fell swoop. Once this is done, any adjustments to anchor positions or bases or marks take effect immediately.
The side benefit is that, once the anchors are present and set up this way, Glyphs will automatically generate the mark-to-base and mark-to-mark features.
I have not run into any problems with this workflow. I have better control over placement of accents than before, less chance of missing something, and less endless tedium.
I created a Mark Positioning lookup and so far everything went smoothly. The process is not that complicated, even if I understand the time it takes. However, the subsequent generation of accented glyphs is rapid.
A doubt instead on the creation of the Mark to Mark lookup.
There are glyphs where the composite diacritics are differently positioned.
Let me clarify.
Consider for example the uni022B glyphs (Latin Small Letter o with dieresis and macron) and uni1E4F (Latin Small Letter o with tilde and dieresis). It is evident that the dieresis is the lowest diacritic in the first case and the highest in the second case.
Which glyph should be considered Base and which Mark? Do I have to create two different Anchor Classes in the same lookup by entering the dieresis once as a Base and one as Mark? Or what other technique should be followed?
What is the procedure for distant diacritics?
For example, Latin Capital Letter O with horn and dot below (uni1EE2), or Latin Small Letter r with dot below and macron (uni1E5D)...
Now I begin to study the case...
For the horn, in particular, if one is finicky about quality, positioning relative to the U is tricky, and usually the shape needs adjustment to blend into the O nicely.
Similar issues exist for the ogonek.
The cedilla and non-attached accents are generally fine with using anchors.
(Note: the horn is required for Vietnamese, and the ogonek for Polish, Lithuanian, and a number of less commonly-supported languages.)
A last little aestetic question: in the case os composite glyphs as circumflex -acute / grave, do you prefer to set there glyphs the first one below and the second one above, or set them next to each other, on the same baseline?
I’ve seen typefaces in which all the other accent combinations are vertically stacked, but with the circumflex, the grave or acute is placed beside the circumflex instead of above it. I might have guessed this would be due to vertical spacing issues, but that doesn’t match what I see done:
I am not convinced this is better. Looks pretty weird, particularly given that the grave or acute might end up mostly over a different, adjacent letter.
In fact, stacking the two diacritics produces not so good results at the height.
The mixed solution indicated by @Thomas is probably the best for certain glyphs.
However, in the case of the font I'm working on, this mixed solution is made difficult by the rather conspicuous size of the diacritics.
At this point another idea comes to me, I don't know if it is anomalous or distant from the more consolidated practice.
What if I create accents (grave and acute etc.) that are a little smaller for compound glyphs? What do you think?
Since I proceed by trial and error, I did this:
- I reduced the circumflex;
- I produced a smaller acute accent and above all with a greater "slope" (I don't know the correct typographical term to indicate the inclination of a glyph).
Here is the current result:
The end justifies the means?
It seems to me that the solution proposed here is very similar to the wise mixed solution of @Thomas.