Birdfont facilitates the creation of mark-to-base positioning by utilizing classes for diacritic mark classes. Here's a step-by-step guide on how to use this feature:
Create a Source Mark:
Generate a source mark for the diacritic you intend to use. (Shift-A)
Add to Class
Add the mark into the appropriate class. (Shift-A)
Import Mark Class to Base Glyph:
Use the mark class in the base glyph and position the mark appropriately. (Shift-A)
By following these steps, you gain the flexibility to place mark classes on any base glyph. This capability is particularly valuable in scripts like Hebrew or Arabic.
Hebrew usecase:
Base Glyph: ש (Shin)
Mark Glyph: ַ (Patach)
Arabic usecase:
Base Glyph: ب (Ba)
Mark Glyph: ٍ (Kasra)
You can also expand the mark class by adding additional glyphs to the class (for example damma or fatha).
Moreover, this functionality is also beneficial when working with Cyrillic or Latin scripts, enabling precise mark class placement on various glyphs.
Latin example:
Marks: 1, 2, or 3
Base: a
Examples: a+1 results in a1 a+2 results in a2 a+3 results in a3