Is there a way to turn on custom font OpenType features? I'm looking for something equivalent to CSS font-feature-settings on web.
No, these aren't directly supported by the FreeType library that Roku OS uses for font rendering.
Based on FreeType FAQ:
...the following features are not supported directly by the library, even though they can be more or less implemented on top of it, or by using it.
Text layout: The library doesn't support text layout operations. Sophisticated features like glyph substitution, positioning (kerning), justification, bi-directional ordering, etc., are not part of a font service in itself. They must be handled (at least) one level higher.
I understand that FreeType is meant to be a basic font service. Other abilities have to be implemented on top of that. Can you please confirm that Roku doesn't have any additional features built on top of FreeType to enable them at all?
We have started using the HarfBuzz library with Roku OS 13.0 to enable better text shaping, but we don't use any other libraries on top of FreeType at this time.
That is a great news. Harfbuzz does support OpenType features. It seems like there is an option to make such capability available. Is there a plan to allow Roku developers to turn on OpenType features in the near future?
Nothing has been announced.