Add OTC font support for `-dfont-ps-resdir`

Add OTC font support for `-dfont-ps-resdir`

This commit adds support for OpenType/CFF collection (OTC) fonts
to the `-dfont-ps-resdir` option.

Add `ly:extract-subfont-from-collection`

Extract the subfont in TrueType collection (TTC)
or OpenType/CFF collection (OTC) file and write it to file.

[lemzwerg, 2020-05-03 15:20:17]

LGTM, with some nits

https://codereview.appspot.com/548080043/diff/573790043/Documentation/usage/r...
File Documentation/usage/running.itely (right):

https://codereview.appspot.com/548080043/diff/573790043/Documentation/usage/r...
Documentation/usage/running.itely:663: this method cannnot embed CID fonts with
Ghostscript 9.26 and later.
s/cannnot/cannot/

https://codereview.appspot.com/548080043/diff/573790043/lily/open-type-font-s...
File lily/open-type-font-scheme.cc (right):

https://codereview.appspot.com/548080043/diff/573790043/lily/open-type-font-s...
lily/open-type-font-scheme.cc:421: "ttcTag", collection.c_str ()));
Why "ttcTag"?  I would rather call this "TTC tag".

https://codereview.appspot.com/548080043/diff/573790043/lily/open-type-font-s...
lily/open-type-font-scheme.cc:428: warning (_f ("font file `%s' is not
collection font",
s/not collection font/not a font collection/

https://codereview.appspot.com/548080043/diff/573790043/lily/open-type-font-s...
lily/open-type-font-scheme.cc:437: warning (_f ("cannot read %s of `%s'",
font `%s': cannot read `Version' field

https://codereview.appspot.com/548080043/diff/573790043/lily/open-type-font-s...
lily/open-type-font-scheme.cc:446: warning (_f ("font file `%s' TTC header
version is unknown",
→ ... `%s': invalid TTC header version

https://codereview.appspot.com/548080043/diff/573790043/lily/open-type-font-s...
lily/open-type-font-scheme.cc:455: warning (_f ("cannot read %s of `%s'",
font `%s': cannot read `numFonts' field

https://codereview.appspot.com/548080043/diff/573790043/lily/open-type-font-s...
lily/open-type-font-scheme.cc:478: warning (_f ("cannot read %s of `%s'",
font `%s': cannot read offset of subfont %d

https://codereview.appspot.com/548080043/diff/573790043/lily/open-type-font-s...
lily/open-type-font-scheme.cc:495: warning (_f ("cannot read %s of `%s'",
→ font `%s': cannot read `sfntVersion' field of subfont %d

https://codereview.appspot.com/548080043/diff/573790043/lily/open-type-font-s...
lily/open-type-font-scheme.cc:504: warning (_f ("font file `%s' index %d does
not have valid sfntVersion",
font `%s': invalid `sfntVersion' field in subfont %d

https://codereview.appspot.com/548080043/diff/573790043/lily/open-type-font-s...
lily/open-type-font-scheme.cc:513: warning (_f ("cannot open font filename
`%s'",
→ cannot open font `%s' for writing

https://codereview.appspot.com/548080043/diff/573790043/lily/open-type-font-s...
lily/open-type-font-scheme.cc:523: warning (_f ("cannot write %s of `%s'",
font `%s': cannot write `sfntVersion' field

etc., etc. for remaining messages

[trueroad, 2020-05-04 02:21:25]

Improve messages

[trueroad, 2020-05-04 02:33:27]

Thank you for your reviewing.

https://codereview.appspot.com/548080043/diff/573790043/Documentation/usage/r...
File Documentation/usage/running.itely (right):

https://codereview.appspot.com/548080043/diff/573790043/Documentation/usage/r...
Documentation/usage/running.itely:663: this method cannnot embed CID fonts with
Ghostscript 9.26 and later.
On 2020/05/03 15:20:16, lemzwerg wrote:
> s/cannnot/cannot/

Done.

https://codereview.appspot.com/548080043/diff/573790043/lily/open-type-font-s...
File lily/open-type-font-scheme.cc (right):

https://codereview.appspot.com/548080043/diff/573790043/lily/open-type-font-s...
lily/open-type-font-scheme.cc:421: "ttcTag", collection.c_str ()));
On 2020/05/03 15:20:17, lemzwerg wrote:
> Why "ttcTag"?  I would rather call this "TTC tag".

The TTC Header Version 1.0 and 2.0 tables of `4.6.3 TTC header' in `ISO/IEC
14496-22 Open Font Format' names it "ttcTag" instead of "TTC tag".

Also, `TTC Header'
https://docs.microsoft.com/en-us/typography/opentype/spec/otff#ttc-header
in `OpenType specification version 1.8.3'
https://docs.microsoft.com/en-us/typography/opentype/spec/
uses "ttcTag" instead of "TTC tag".

https://codereview.appspot.com/548080043/diff/573790043/lily/open-type-font-s...
lily/open-type-font-scheme.cc:428: warning (_f ("font file `%s' is not
collection font",
On 2020/05/03 15:20:16, lemzwerg wrote:
> s/not collection font/not a font collection/

Done.

https://codereview.appspot.com/548080043/diff/573790043/lily/open-type-font-s...
lily/open-type-font-scheme.cc:437: warning (_f ("cannot read %s of `%s'",
On 2020/05/03 15:20:17, lemzwerg wrote:
> font `%s': cannot read `Version' field

Done.

https://codereview.appspot.com/548080043/diff/573790043/lily/open-type-font-s...
lily/open-type-font-scheme.cc:446: warning (_f ("font file `%s' TTC header
version is unknown",
On 2020/05/03 15:20:17, lemzwerg wrote:
> → ... `%s': invalid TTC header version

Done.

https://codereview.appspot.com/548080043/diff/573790043/lily/open-type-font-s...
lily/open-type-font-scheme.cc:455: warning (_f ("cannot read %s of `%s'",
On 2020/05/03 15:20:17, lemzwerg wrote:
> font `%s': cannot read `numFonts' field

Done.

https://codereview.appspot.com/548080043/diff/573790043/lily/open-type-font-s...
lily/open-type-font-scheme.cc:478: warning (_f ("cannot read %s of `%s'",
On 2020/05/03 15:20:17, lemzwerg wrote:
> font `%s': cannot read offset of subfont %d

Done.

https://codereview.appspot.com/548080043/diff/573790043/lily/open-type-font-s...
lily/open-type-font-scheme.cc:495: warning (_f ("cannot read %s of `%s'",
On 2020/05/03 15:20:16, lemzwerg wrote:
> → font `%s': cannot read `sfntVersion' field of subfont %d

Done.

https://codereview.appspot.com/548080043/diff/573790043/lily/open-type-font-s...
lily/open-type-font-scheme.cc:504: warning (_f ("font file `%s' index %d does
not have valid sfntVersion",
On 2020/05/03 15:20:17, lemzwerg wrote:
> font `%s': invalid `sfntVersion' field in subfont %d

Done.

https://codereview.appspot.com/548080043/diff/573790043/lily/open-type-font-s...
lily/open-type-font-scheme.cc:513: warning (_f ("cannot open font filename
`%s'",
On 2020/05/03 15:20:17, lemzwerg wrote:
> → cannot open font `%s' for writing

Done.

https://codereview.appspot.com/548080043/diff/573790043/lily/open-type-font-s...
lily/open-type-font-scheme.cc:523: warning (_f ("cannot write %s of `%s'",
On 2020/05/03 15:20:17, lemzwerg wrote:
> font `%s': cannot write `sfntVersion' field
> 
> etc., etc. for remaining messages

Done.

[lemzwerg, 2020-05-04 04:33:59]

Thanks for the changes.  Here the next round of comments :-)

https://codereview.appspot.com/548080043/diff/567530058/lily/open-type-font-s...
File lily/open-type-font-scheme.cc (right):

https://codereview.appspot.com/548080043/diff/567530058/lily/open-type-font-s...
lily/open-type-font-scheme.cc:467: warning (_f ("font index %d too large for
font `%s', using index 0",
Maybe it makes sense to use a format like

  font `%s': ...

here, too.

https://codereview.appspot.com/548080043/diff/567530058/lily/open-type-font-s...
lily/open-type-font-scheme.cc:495: warning (_f ("font `%s': cannot read `%s'
field of subfont %d",
Shall we do

  s/`%s' field/field `%s'/

here and in the following messages?  Ditto

  s/`%s' table/table `%s'/

later on.  We already have `font xxx' and `subfont yyy'...

https://codereview.appspot.com/548080043/diff/567530058/lily/open-type-font-s...
lily/open-type-font-scheme.cc:513: warning (_f ("font `%s': cannot open for
writing",
Shall we replace `font' with `subfont' here and in succeeding write messages?

https://codereview.appspot.com/548080043/diff/567530058/lily/open-type-font-s...
lily/open-type-font-scheme.cc:594: " table no. %u of subfont %d",
s/table no. %u/table %u/

[trueroad, 2020-05-04 05:43:28]

Improve messages again

[trueroad, 2020-05-04 05:45:23]

Thank you for your reviewing.

https://codereview.appspot.com/548080043/diff/567530058/lily/open-type-font-s...
File lily/open-type-font-scheme.cc (right):

https://codereview.appspot.com/548080043/diff/567530058/lily/open-type-font-s...
lily/open-type-font-scheme.cc:467: warning (_f ("font index %d too large for
font `%s', using index 0",
On 2020/05/04 04:33:59, lemzwerg wrote:
> Maybe it makes sense to use a format like
> 
>   font `%s': ...
> 
> here, too.

Done.

https://codereview.appspot.com/548080043/diff/567530058/lily/open-type-font-s...
lily/open-type-font-scheme.cc:495: warning (_f ("font `%s': cannot read `%s'
field of subfont %d",
On 2020/05/04 04:33:59, lemzwerg wrote:
> Shall we do
> 
>   s/`%s' field/field `%s'/
> 
> here and in the following messages?  Ditto
> 
>   s/`%s' table/table `%s'/
> 
> later on.  We already have `font xxx' and `subfont yyy'...

Done.

https://codereview.appspot.com/548080043/diff/567530058/lily/open-type-font-s...
lily/open-type-font-scheme.cc:513: warning (_f ("font `%s': cannot open for
writing",
On 2020/05/04 04:33:59, lemzwerg wrote:
> Shall we replace `font' with `subfont' here and in succeeding write messages?

Done.

https://codereview.appspot.com/548080043/diff/567530058/lily/open-type-font-s...
lily/open-type-font-scheme.cc:594: " table no. %u of subfont %d",
On 2020/05/04 04:33:59, lemzwerg wrote:
> s/table no. %u/table %u/

Done.

[trueroad, 2020-05-09 09:03:43]

I've pushed to staging.

commit 116b2765ea458daa4ab32a7ecaff79eb0ab5306f
Issue 5960/3: Doc: Remove unnecessary description about `-dfont-ps-resdir`

commit a2ff250f1fb4adb23c82000affe475ef34820cc6
Issue 5960/2: Add OTC font support for `-dfont-ps-resdir`

commit 92db18d3141484d3c46722f6ed911c253e06d0f4
Issue 5960/1: Add `ly:extract-subfont-from-collection`