Re: Cairo plans

[Masamichi Hosoda]

> I analyzed more closely in the issue
> https://gitlab.com/lilypond/lilypond/-/issues/6172
> 
> Would you know how the mapping of character index => codepoint is
> supposed to work for this font with character 3056 (辻) ?

Most PDF readers have a mapping
from Adobe-Japan1 CID to Unicode code points as follows.
https://github.com/adobe-type-tools/mapping-resources-pdf/blob/master/pdf2unicode/Adobe-Japan1-UCS2

In the case of Acrobat Reader on Windows, it is stored in the following path.
C:\Program Files (x86)\Adobe\Acrobat Reader DC\Resource\CMap\Adobe-Japan1-UCS2

The number 3056 in the Adobe-Japan1 CID is 0xbf0 in hexadecimal.
The Adobe-Japan1-UCS2 file contains the following line,
which shows that CID 0xbf0 is U+8FBB.
https://github.com/adobe-type-tools/mapping-resources-pdf/blob/20190401/pdf2unicode/Adobe-Japan1-UCS2#L2329

```
<0bf0> <8fbb>
```

In the case of poppler, the file format is different,
but the following file has a similar mapping.
https://gitlab.freedesktop.org/poppler/poppler-data/-/blob/master/cidToUnicode/Adobe-Japan1

There is a Unicode code point at line 3056 + 1 (i.e. line 3057),
which shows U+8FBB.
https://gitlab.freedesktop.org/poppler/poppler-data/-/blob/POPPLER_DATA_0_4_10/cidToUnicode/Adobe-Japan1#L3057