In vignettes, Replaced \hbox with \text, which is better supported by KaTeX (and other engines).
Shipped the KaTeX math fonts using the pkgdown customization mechanism pkgdown/extra.css and pkgdown/assets/fonts/. This is because pkgdown 2.1.0 did not bundle them (not sure why) and the default math font rendering is subpar.
Alternative paths
Apparently, MathML doesn't render very well for our formulas. Although we can choose the old default MathJaX, the font bundling situation is a bit more challenging to fix using the same customization approach as the fonts were defining in JS (I successfully converted them to CSS). Considering that KaTeX is faster and simpler, I think it's the optimal choice.
What's in this PR
This PR brings back glorious math rendering to the pkgdown vignettes by switching the math rendering engine to KaTeX supported in pkgdown 2.1.0.
Before and after
This is what an example vignette section looks like before, current, and after this patch.
pkgdown 2.0.9 (old default, MathJax)
Click to expand screenshot
pkgdown 2.1.0 (new default, MathML)
Click to expand screenshot
pkgdown 2.1.0 + KaTeX
Click to expand screenshot
Method
To make this work, I did two things:
\hboxwith\text, which is better supported by KaTeX (and other engines).pkgdown/extra.cssandpkgdown/assets/fonts/. This is because pkgdown 2.1.0 did not bundle them (not sure why) and the default math font rendering is subpar.Alternative paths
Apparently, MathML doesn't render very well for our formulas. Although we can choose the old default MathJaX, the font bundling situation is a bit more challenging to fix using the same customization approach as the fonts were defining in JS (I successfully converted them to CSS). Considering that KaTeX is faster and simpler, I think it's the optimal choice.