Re: Font rendering question - Apple Color Emoji.ttc

[Werner LEMBERG]

> After failing to figure out run a debug build of FreeType and get
> the output, I started just investigating with print statements.

Sorry, I should have pointed to

  https://gitlab.freedesktop.org/freetype/freetype/-/blob/master/docs/DEBUG

how to activate debugging messages.

> I found that the error is coming from
> https://gitlab.freedesktop.org/freetype/freetype/-/blob/master/src/sfnt/ttsbit.c?ref_type=heads#L1555
> - the ‘graphicType’ tag that is unsupported is ‘flip’.  This makes
> sense for 'woman in a manual wheelchair facing right’.

Thanks for the analysis.  The good news is that PNG support in 'sbix'
should be fully supported, so supporting this feature would be nice.
The bad news is that a 'flip' tag is neither documented in Microsoft's
OpenType nor in Apple's TrueType specification...

I now see that the fonttools package supports it:

  https://github.com/fonttools/fonttools/pull/3433

and it seems that you came to the same conclusion as me, based on your
comments there :-)

> So this is indeed a feature that FreeType doesn’t support. I gather
> from your response that this is not at all a priority.

Correct, but...

> Alternatively, if I felt inspired, and somehow figured this out,
> would it be worthwhile for me to create a merge request?

... this would be very welcomed, given that flipping a bitmap
horizontally is not a big deal and should only require a few lines of
code, I reckon.

> create an issue this over at
> https://gitlab.freedesktop.org/freetype/freetype,

Yes, please do.


    Werner