On 2022-03-11 18:16, Hans Hagen via ntg-context wrote:
Hi,
It has been a while since there was an updaste but there it is. The
most significant 'changes' are:
- more automatic adaption to double sided page properties in metafun
(lmtx) ... blame sreeram and me for messing up
- more extensibve support for indic fonts which sreeram has documented
on the wiki (fonts, translutaration etc)
and
- improved math rendering to be documented by by mikael in an upcoming
manual ... it tooks a couple of months so it is supposed to have some
impact.
before we move on the the structural compoments and see what can be
done beter there, we decided to release the first stage that deals with:
= fixing font properties; we don't expect fonts to be improved so
that's the route we follow
= extensive inter atom spacing (we have many more math classes, some
in the engine, some in context) and everything can be controlled (the
old pairwise spacing primitives have been replaced by a more general
mechanism, including support for fast setup of categories and
inhertance from other classes)
= idem for inter class penalties, including granular control over line
breaks using a system of (in/de)creasing penalties
= auto-fenced inline material across lines and linebreaks in molecules
(read: complex atoms)
= taking stretch and shrink in encapsulated atoms into account in
linbreaks (using some new box related mechanism that is also available
in text and will be explained later)
= spacing at the edges that should not be there but always was there
as side effect of the engine is now removed; as with other new
features this can be controlled (we have rulesets for atoms to which
we can add more in the future)
= more detailed control over (skewed) fractions, (flattened) accents,
(sized) fences, radicals ... there was already a lot there but it now
combines with mentioned spacing (when relevant the context macros have
been adapted to control this which is a bit cleaner)
= we have a new built in muskip (tiny) but as we have an inheritance
system as well as binding to variables one can set up extensive
spacing models register and constant binding; the currently set values
are based on math typesetting references; in the future we might have
additional ones
= although we did handle primes already rather transparent in mkiv /
lmtx, inconsistency in fonts made us decide to make primes first class
properties of atoms and molecules which means that we now have: pre
super/subscripts, post super/subscripts and primes; this permits nicer
anchoring under parameter control
= there are more font parameters to control matters (they are not in
open type but we sort of assume they are); the options that we had to
control how the engine deals with fonts are now driving the process
(without them being set not much is applied) and we basically assume
open type fonts (where one can enable engine options for those kind of
fonts but also for traditional); some experimental options for testing
are gone
= in the process tracing for what is done in math by the engine has
been extended (mostly for ourselves)
= instead of auto patching math fonts most is now under control of the
goodie files; user can (as usual) make their own, but also ask Mikael
to add missing bits and pieces (wrt dimensions)
= most known math fonts are dealt with but there are a few exceptions:
we no longer consider asana to be useful (it doesn't pass our qa and
needs too much patching); erewhon is also troublesome (dimensions,
missing shaped) as is concrete (idem) so we decided not to waste too
much time on them now
= we probably need to freeze math fonts in the distribution and only
update when we know what has been changed
= we got rid of quite some artifacts that normally go unnoticed (like
tiny added spaces that result from always applied spacing even if not
needed and/or to compensate for glyph features like too much or little
side bearing): by fixing inconsistencies in fonts we could get rid of
all and therefore inter atom spacing is what does the job; once you
know it, you see it and there is no going back
= because we zoom in we notice these things but much went unnoticed
(or was just accepted) for years; it means that we think some of the
things we did qualify as math micro typography (like it or not) and it
does mean that documents can render differently (unlikely for display,
propably also for inline unless you have plenty of math in a paragraph)
== our objective has been to make it easier for users and to get rid
of explicit spacing; for that we also introduced commands for
differentials (that have their own class), imaginary numbers (also
have their class) and we added exponential as class; fwiw, digits and
factorial are classes too so again spacing has been optimized for them
= whatever i forgot in the meantime mikael will add to this list
There is a rough description in the 'ontarget' do
