Comparison with UniPsaltica2

[basil]

What are the advantages and disadvantages of the approach taken here compared to the approach taken in UniPsaltica2?

[danielgarthur]

The main difference I see is that SBMuFL uses mark-to-base and mark-to-mark positioning to align supporting neumes, whereas UniPsaltica2 uses single positioning.

Mark-to-base and mark-to-mark positioning is more powerful and has easier tooling (at least within Font Forge) to position things quickly. Positioning marks relative to other marks is not possible with single positioning, either.

Both approaches have the issue that Webkit, Latex, and several PDF libraries that I've tried do not render supporting neumes correctly when the color is different, so manual positioning is necessary in those contexts, for now.

[basil]

Both approaches have the issue that Webkit, Latex, and several PDF libraries that I've tried do not render supporting neumes correctly when the color is different, so manual positioning is necessary in those contexts, for now.

Are there tickets filed with minimal reproducible examples for these issues? If not, perhaps I could help. I work on open-source software professionally and frequently work across the boundaries of different open-source projects. In my experience, half of the battle is explaining the relevance of the use case and doing the appropriate testing. If that is done, maintainers are often willing to do much of the work to fix the issue, or else explain in detail what needs to be done for an outside contribution to be accepted.

[danielgarthur]

There's a good explanation of the issue here and the specific case of color is here.

The webkit bug report has been around since 2005. Chromium addressed it in 2022 with the new layout engine.

As far as Latex and PDF libraries go, I would first want to check where the issue lies. It may be an issue with the underlying shaping engine itself, not with the libraries. It may even be a limitation in the PDF format and Chromium may be simply manually positioning the PDF elements to get around it.

[danielgarthur]

I stand corrected on Latex. There is a library called luacolor that shapes across boundaries. I can't, however, figure out how to make it also allow marks to be offset by an additional amount. In Chromium this can be done by simply adding CSS top/left.