Re: [ft-devel] Loading empty bitmap fails?

[Behdad Esfahbod]

On Fri, Aug 4, 2017 at 9:52 PM, Werner LEMBERG <address@hidden> wrote:

> With color fonts, I'm finding that loading space character is
> failing with FreeType even though there's cmap entry in the font.
> It should result in empty glyph bitmap IMO.  NotoColorEmoji
> reproduces for me, as does emojione-apple.ttf

Indeed.  Can you give me pointers to the OpenType specification where
this situation is covered?  Currently, I don't find it...

I cannot, because as it happens nowhere it says that it is an error if a strike does not contain an image for a glyph. :-)

Joking aside, from the spec's point of view, bitmaps always accompanied outline shapes.  In that situation, a missing bitmap meant "use outline".  With CBLT/CBDT color fonts, there is no outlines and it is expected that any needed shape be present in all strikes.  I think it's a logical follow up that if a strike does not provide a bitmap for a glyph, that glyph has no drawing.

--

behdad
http://behdad.org/