Re: Tamil fonts (Was: bug#55745: [PATCH] Add support for the Hanifi Rohingya script)

[समीर सिंह Sameer Singh]

Then can we do something like

  (set-fontset-font "fontset-default" '(#x11FC0 . #x11FFF)
                    '("Noto Sans Tamil Supplement" . "iso10646-1") nil 'prepend)

in lisp/international/fontset.el?

After doing this both the "base" and supplement characters are being displayed correctly.

On Wed, Jun 1, 2022 at 11:09 PM Eli Zaretskii <eliz@gnu.org> wrote:

> From: समीर सिंह Sameer Singh <lumarzeli30@gmail.com>
> Date: Wed, 1 Jun 2022 22:25:52 +0530
> Cc: Eli Zaretskii <eliz@gnu.org>, emacs-devel@gnu.org
>
>  This is a sub-optimal solution IMHO.  There will always be cases where
>  a script is split into multiple Unicode blocks, probably mapped to
>  different fonts.  AFAICS, the Tamil supplement characters don't
>  interact typographically with normal Tamil characters, so a two-font
>  solution in this case is valid.  In case my assumption is invalid you
>  should submit a bug to the Noto project :-)
>
> I agree it is somewhat sub optimal, but Emacs does not differentiate between supplement and "base"
> characters, so setting different fonts for both of them does not seem possible.

Of course, it's possible: set-fontset-font can accept ranges of
codepoints and use different font for each range.  It doesn't have to
accept only script names.

> There also seems to be no font which supports both Tamil and its supplement characters OOTB.

That part is indeed sub-optimal, but not a catastrophe if they are
displayed independently, i.e. there are no composition rules that
cross the boundary between the blocks.