A little info about ligatures and e.g. Calibri

[Khaled Hosny]

On Sun, Feb 03, 2013 at 03:39:36PM +0000, Caolán McNamara wrote:
> FWIW, as it came up as a question in the main track FOSDEM LibreOffice
> talk, in vcl/generic/glyphs/gcach_layout.cxx see IcuLayoutEngine::layout
> and...
> if (rArgs.mnFlags & SAL_LAYOUT_ENABLE_LIGATURES)
>     nLayoutFlags |= LayoutEngine::kTypoFlagLiga;
> so ligatures are disabled by default unless SAL_LAYOUT_ENABLE_LIGATURES
> is enabled, and SAL_LAYOUT_ENABLE_LIGATURES is only set if
> TEXT_LAYOUT_ENABLE_LIGATURES is set on the outputdevice, and that
> doesn't happen anywhere as of yet :-(

I was wondering about this a while ago, but thought it was just me not
finding where the magic is.

> It would be no major problem to e.g. bubble up allowing those ligatures
> to be set explicitly via the UI, or e.g. defaulted on via a new
> compatibility flag for new docs, but the last time I played around with
> it I ran into the snag that with our current Linux rendering stack via
> cairo we get the unfortunate visual effect that ligatures appear bold in
> Calibri, etc.

I see Calibri only, no etc's :), so blocking ligature support (which is
so 80s, even MS Office now supports OpenType features for Latin) because
is of a bug in a single font in certain configurations is overreacting
IMHO.

Regards,
Khaled