Math commands \bar and \tilde

[elpinal]

I really, and often, need math commands \bar and \tilde as in LaTeX. I know monaqa/satysfi-azmath provides implementations of such commands but they are unsatisfactory: the user of the commands is required to supply a floating-point number to align bars or tildes; this is impractical because the number is font-dependent. I want LaTeX-quality implementations of \bar, \tilde, \hat, \vec, etc. to be in the standard library. Then my question is: "how difficult to implement?" "what is the stumbling block?"

[TonalidadeHidrica]

Here is an explanation that @gfngfn made, that may partially describe the reason:

Regarding with mathematical accents, I inspected the specification of MathTopAccentAttachment table in MATH table of OpenType, only to find that while the horizontal positions of annotating accents are stored, there are no information about the vertical ones but "determined by different means", and I'm like heeeeey no kidding plzzzzzz

From https://twitter.com/bd_gfngfn/status/1097494773194121216, translated by @TonalidadeHidrica

So,

• For the horizontal positions, we know which data of a font file we should refer to.
• For the vertical positions, we still have no idea what should we rely on.

And probably the lack of the latter info is blocking the resolution.

[elpinal]

Thank you for the information. I'm going to understand the OpenType MATH table.