Re: Important information about the MathML fonts in Gecko 31

Le 22/07/2014 08:51, William F Hammond a écrit :
> Why should it be necessary to remove support for old fonts just 
> because new things will be supported? -- Bill 
I supposed you understood that it is not "just because new things will 
be supported" ;-)

First the Unicode-only constructions in arbitrary fonts will still be 
supported, what we want to remove is the old font tables for Asana Math, 
"STIX General" and MathJax. Asana Math and the "STIX Word" set have an 
OpenType MATH table so can be used with the new code. Additionally, 
Latin Modern Math is a "modernized implementation of the Computer Modern 
fonts" (with reshaping and other stuff that are out of my area of 
expertise, see the papers on the GUST website for details) and so can 
now replace the "MathJax TeX" fonts (which is just generated via an 
autotracer, targeted to MathJax's needs and was a temporary solution to 
replace the old BaKoMa TeX support). So first, nobody should need these 
old fonts in the long term since you have equivalent OpenType MATH 
version... why do you want that??

The technical reason why we want to remove support for these old fonts 
is that they need special handlings which make the stretchy operator 
code "complicated" (to use an euphemism). Since we want to optimize it 
in the future, we will need to cleanup the code before refactoring it. 
Moving to OpenType MATH has actually been the plan for 7 years, but that 
finally could only be realized recently, thanks to the Ulule crowdfunding...

Moreover, from the user's point of view, you will get a much more 
consistent way to use the various OpenType MATH fonts in WebKit/Gecko. 
Basically, you now have only one single Math font to deal with and only 
need to set the font-family on the <math> (and perhaps the companion 
fonts for the text). All the mathvariant selection, correction of prime 
size, math layout parameters, stretchy op constructions etc are stored 
in the font and Gecko&WebKit only need to read what has been specified 
by the font authors. One can even create his own math fonts with 
fontforge and they will be immediately supported by Gecko&WebKit without 
having to hardcode new data. For example, if some Mathematica people 
read that, they could just make an OpenType MATH version of their fonts 
and restore the original 15-years old support in Gecko :-)

-- 
Frédéric Wang
maths-informatique-jeux.com/blog/frederic

Received on Tuesday, 22 July 2014 17:43:20 UTC