Re: GSoC 2020 update, June 15

[Carl Sorensen]

On Mon, Jun 15, 2020 at 4:00 PM Owen Lamb <owendlamb@gmail.com> wrote:
>
> Hi all,
>
> Apologies for the lateness of this update. Last week was mostly research
> into stylistic alternates and how to support OpenType features in a SMuFL
> font, so not much was done in the way of code changes aside from creating a
> proof-of-concept stylistic alternate mapping.
>

The update may be formally late, but you had conversation on the list
last week, so I don't see any problem.

<snip>
>
> So, my game plan for this week is as follows: while I correspond with
> HarfBuzz, I will generate a JSON file for Emmentaler. Then, I will have
> open-type-font.cc try to load a font's JSON file, and if that fails its
> GSUB table, into some sort of Scheme object (perhaps an alist?), which can
> then be read (or written--who knows if a user might want to mess with font
> metadata!) by LilyPond. I will probably need to create another
> font-specific Scheme alist so that specific font features, such as
> ligatures, alternates, or style sets, can be turned on or off at any point,
> telling HarfBuzz (or whatever glyph-replacing method we go with) which of
> them to use at any given moment.

I think that you should use a hash table, rather than an alist.  As I
understand it, you'll be creating it once, and accessing it many
times.  The extra computation to create a hash table will be repaid
many times over in the lookup.

>
> (A SMuFL font's metadata file also includes settings such as staff line
> thickness, etc. for drawing primitives in their correct proportions, so
> I'll eventually need to make LilyPond respect those as well. But one step
> at a time!)
>

> Once again, if you have any worries/suggestions, please let me know. I plan
> to send my next update on time, on Friday.
>

Thanks for your good work.  I'm excited to see this happening!

Carl