Font fallback should allow selection of a Mul font #75

This issue is applicable to Khmer script orthographies.

Modern Khmer has several distinct styles of font, each of which is used for different purposes. The round style (អក្សរមូល /ʔɑːksɑː muːl/) has heavier, more rounded letter shapes, and includes more ligated forms. It is commonly used for titles and headings in Cambodian documents, books, or currency, as well as on shop signs or banners. It may also be used to emphasise important names or nouns. The regular font weight looks like bolded text in comparison to the upright font style.

Authors using a Mul font in their text should be able to indicate that any font fallback picks a Mul font, rather than a random Khmer font. Otherwise, the distinctions between certain types of text on a page may be lost.

More:

• Cambodian (Khmer) Orthography Notes/Font styles
• Wikipedia
• Khmer system fonts

The original GAP

Currently there is no way to tell the browser to fall back to a Mul font, rather than another font.

Neither Gecko, Blink, nor Webkit support this. Before they can, CSS needs to provide a way for authors to indicate that a khmer mul generic font should be used.

Priority

This is a useful feature for Khmer, which uses the Mul style frequently in documents and signage. Marking as Advanced, since there is not the imperative to use such a font (unlike some other font styles). Some may see this as Basic, given the prevalence of this convention.

Tests & results

Interactive test, font-family:generic(khmer-mul) will apply a Mul font in Khmer

The following pages may be useful for checking the test results:

• Khmer Mul fonts available from Windows, and SIL (No fonts available from macOS, or Noto)

Action taken

Discussion document: Generic font families

CSS discussion threads:

• Add generic font family, Khmer Mul (Closed)

Browser bug reports: Gecko • Blink • WebKit

Platform Status: Blink

Outcomes

The CSS Fonts 4 spec now defines a generic(ident) syntax which will be used for newly-introduced, and especially for script-specific, generics.

The CSS WG resolved to add this as a new generic font family, and generic(khmer-mul) is now in CSS Fonts 4.

Browsers are not yet supporting it.