Description
I figure this is probably goes along with adding support for hinting. However there is some fonts where a lot of data is missing because of the lack of support for Font Variations. The two major variations for this are as follows:
Variation 1: Apple Advanced Typography (AAT) - This is Apple's Variation on TrueType Fonts, and has a slightly different signature than OpenType. This is still a good reference since a lot of the behavior is the same in this, and OpenType. The only difference may be the table name is changed.
Variation 2: OpenType Version 1.8.2 or newer - This includes most of the tables used by Apple, and adds a few mores. Also, Collections for OpenType use the OTC file extension.
To help with implementation, I have a list of the tables that need implementing to add this feature, and you can find the list in the table below...
| Table Name | Description | AAT Support | OpenType Support |
|---|---|---|---|
| avar | Axis Variations Table | Y | Y |
| cvar | Control Value Variations table. | Y | Y |
| fvar | Font Variation Table | Y | Y |
| gvar | Glyph Variation Table | Y | Y |
| name | Name Table | Y | Y |
| HVAR | Horizontal Metrics Variations | N | Y |
| MVAR | Metrics Variations Table | N | Y |
| VVAR | Vertical Metrics Variations | N | Y |
| ttcf | TrueType Collections Table | N | Y |
Also, Since there is a need for fonts to test to make sure this works, you can find the fonts in the following list. In general these fonts have have two downloadable versions where one version includes the Font Variations, and the other version has the fonts variations as separate font files.
- Adobe Fonts: Note: This font set is currently the best option to test this functionality for users who are not using Chinese/Japanese/Korean (aka CJK).
- Adobe Source Code Pro - https://github.com/adobe-fonts/source-code-pro
- Adobe Source Sans Pro - https://github.com/adobe-fonts/source-sans-pro
- Adobe Source Serif Pro - https://github.com/adobe-fonts/source-serif-pro
- Google's Noto Fonts - This has a lot of fonts, and variations. I recommend just looking at the "Super OTC" version since this is most likely going to be the font which can generate problems since a single font can contain 30+ fonts in this case.
- Noto Sans CJK
- Noto Sans Mono CJK- This font is merged as a sub-font of the Noto Sans CJK Super OTC Font.
- Noto Serif CJK