Re: [ft-devel] Having trouble rendering emojis with FreeType (Re: Freetype-devel Digest, Vol 172, Issue 22)

[Hin-Tak Leung]

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On Thu, 16/5/19, Moazin Khatri <address@hidden> wrote:
 
> Yea, it was stupid of me to try
> setting the size of a bitmap embedded font, whose glyphs are
> fixed size. Lesson learned! :)

I learned that only somewhat recently, a couple of years ago, when I took on 
FontVal - and that's after about 2 decades of interests in Freetype. Never too 
late to learn something :-).

> Also, as far as I understand now,
> with the case of bitmap embedded fonts, a user can look
> inside `face->available_sizes' to list all
> the available sizes and then set the one the user desires.
> Am I correct?
> Regards,Moazin

If you look at the source of ftdump (part of ft2-demos), you'd likely have your 
answer.

Running ftdump on NotoColorEmoji on ubuntu, gives this section:

$ftdump /usr/share/fonts/truetype/noto/NotoColorEmoji.ttf

...
fixed size
     0: height 128, width 136
        size 109.000, x_ppem 109.000, y_ppem 109.000
...

'ftdump /usr/lib/thunderbird/fonts/EmojiOneMozilla.ttf' does not show a "fixed 
size" section.

I don't have the Apple Emoji font on the computer I am typing on right now, but 
if I remember correctly, it contains about 3 or 4 fixed bitmap sizes.

The two freetype-py Emoji rendering examples are : 

https://github.com/rougier/freetype-py/blob/master/examples/emoji-color.py

and 
https://github.com/rougier/freetype-py/blob/master/examples/emoji-color-cairo.py

I left a comment for myself and others on line 21,22 in the latter :-) :

# Not all char sizes are valid for emoji fonts;
# Google's NotoColorEmoji only accept size 109 to get 136x128 bitmaps