Re: Ntemacs chooses wrong font.

["Juanma Barranquero" <lekktu@gmail.com>]

On Wed, Jun 11, 2008 at 14:34, Jason Rumney <jasonr@gnu.org> wrote:

> The problem appears to be that the system API used in one of the encode_char
> functions on Windows (I don't know whether it is uniscribe or gdi) seems to
> return a space glyph for unsupported characters in some fonts, instead of 0
> (which is ".notdef" according to the truetype spec).

FWIW, that's what I see:

  - using gdi (because I've forced Emacs to fail loading usp10.dll or
by using Emacs.fontBackend: gdi) => Emacs "finds" U+2200 at glyph #3
of DejaVu Sans Mono.
  - using uniscribe (by means of Emacs.fontBackend: uniscribe) =>
Emacs correctly finds U+2200 at #421 of MS Mincho.
  - leaving it to itself to choose (no Emacs.fontBackend): it "find"
the #x3 glyph in DejaVu Sans Mono

so it seems gdi-related.

> Perhaps C-u C-x = should also report which font backend a font belongs to,
> to make tracking these sorts of bugs down easier.

BTW, perhaps there should be a (trivial) function to list available
backends. Currently the only way I can see is

   (cdr (assq 'font-backend (frame-parameters)))

and that depends on Emacs.fontBackend not being set to limit the list.

   Juanma