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commontype-standard / commontype

Annotated OpenType Specification
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TrueType versus MSOT #36

Open simoncozens opened 4 years ago

simoncozens commented 4 years ago

A ".ttf file" could be either a TrueType file or a MSOT file, but neither of these formats are complete supersets of the other. For example, a valid TrueType font can have a bhed table, no head table, and no primary outline representation format; this would not be a valid MSOT font, but would be a "valid TTF font" from a user perspective.

If CommonType is aiming to be a description of what is common about fonts with sfnt packages, should it also include TT-specific tables?

alerque commented 4 years ago

It probably should at least cover their existence, but with less detail and emphasis for those bits that are "legacy" TrueType only.

davelab6 commented 4 years ago

I think documentation for anything implemented in any single major implementation is good, as long as it's been publicly documented and is free for anyone ever to implement.

The fact it isn't commonly implemented today don't mean it couldn't be.

davelab6 commented 4 years ago

If course, since we have control over source markup and presentation, we can mark up such sections and clearly communicate their status, likely in the frontmatter

davelab6 commented 4 years ago

Behdad told me in chat today that AAT layout support in harfbuzz has shipped in Chrome, Firefox and Android, so it is now de-facto part of what is commonly implemented