[mpeg-OTspec] Re: [OpenType] Typo in CFF2 specification?

Levantovsky, Vladimir vladimir.levantovsky at monotype.com
Mon May 20 23:30:12 CEST 2019 

Dear Ken, all,

Please see attached the draft of the proposed input contribution that addresses the changes we discussed earlier on this list. Please note that in addition to proposing changes for all numerical references to correct glyph count from 65536 to 65535, I also included the proposed text of the informative note in the end of the description for FDSelect Format3. I think it would be useful to insert the same clarifying note in the OpenType spec.

Thank you,
Vlad


-----Original Message-----
From: mpeg-OTspec at yahoogroups.com <mpeg-OTspec at yahoogroups.com> On Behalf Of Ken Lunde lunde at adobe.com [mpeg-OTspec]
Sent: Thursday, April 11, 2019 4:22 PM
To: opentype-list at indx.co.uk; ​ <mpeg-OTspec at yahoogroups.com>
Subject: Re: [mpeg-OTspec] Re: [OpenType] Typo in CFF2 specification?

Behdad,



Right. I clicked "send" on my reply to your reply at the same time as your followup to your reply came in, hence the apparent disconnect, which was made further confusing by the lag in the mailing lists. Thank you for clarifying.



Will someone take an action to correct this in both versions of the spec?



Regards...



-- Ken



> On Apr 11, 2019, at 1:15 PM, Behdad Esfahbod <behdad at behdad.org> wrote:

> 

> Hi Ken,

> 

> As I said, you are right.  All instances of 65536 should be 65535.  Not because of the sentinel you mention.  But because the "number of items" encoded in 16bits maxes out at 65535.

> 

> On Thu, Apr 11, 2019 at 2:10 PM Ken Lunde lunde at adobe.com [mpeg-OTspec] <mpeg-OTspec-noreply at yahoogroups.com> wrote:

> Behdad, 

> 

> To clarify, would that mean that the valid GID range for Table 12 FDSelect Format 3 and Table 13 Range3 Record Format is 0 through 65535 (and not 0 through 65534)? Given that there is a sentinel CID, I would think that the usable GID range would be 0 through 65534 (65,535 glyphs), not 0 through 65535 (65,536 glyphs). To quote from the "Table 13 Range3 Record Format" section: 

> 

> "A sentinel GID follows the last range element and serves to delimit the last range in the array. The sentinel GID is set equal to the number of glyphs in the font. That is, its value is 1 greater than the last GID in the font." 

> 

> Regards... 

> 

> -- Ken 

> 

> > On Apr 11, 2019, at 10:08 AM, Behdad Esfahbod via OpenType <opentype-listmaster at indx.co.uk> wrote: 

> > 

> > Message from OpenType list: 

> > 

> > 

> >> ****** Attachments to this email message have been removed ****** 

> > 

> > I think only the second instance in this quote is wrong: 

> > 

> > *Note:* While FDSelect format 4 allows for more than 65536 glyphs, other 

> > parts of the OpenType format, such as the numGlyphs field of the 'maxp' 

> > table, are still constrained to 65536 glyphs. 

> > 

> > 

> > 

> > On Thu, Apr 11, 2019 at 12:37 PM Ken Lunde via OpenType < 

> > opentype-listmaster at indx.co.uk> wrote: 

> > 

> >> Message from OpenType list: 

> >> 

> >> 

> >> All, 

> >> 

> >> Can someone double check to make sure that all instances of "65536" in the 

> >> CFF2 specification are correct? See: 

> >> 

> >> https://urldefense.proofpoint.com/v2/url?u=https-3A__nam04.safelinks.protection.outlook.com_-3Furl-3Dhttps-253A-252F-252Fdocs.microsoft.com-252Fen-2Dus-252Ftypography-252Fopentype-252Fspec-252Fcff2-26data-3D02-257C01-257CLunde-2540adobe.com-257C2565f8ba25964978940f08d6bea0f6b5-257Cfa7b1b5a7b34438794aed2c178decee1-257C0-257C0-257C636905995905347520-26sdata-3DgmTML4sP-252B7C8dOtC6zcb-252FI9vTovfYusnC8-252BVqsYV3JM-253D-26reserved-3D0&d=DwICaQ&c=euGZstcaTDllvimEN8b7jXrwqOf-v5A_CdpgnVfiiMM&r=jb2T9D8Np5j0t1X2JtGDVJ6FPFtBJQsSkOo2WUrCs2wDaDMjubx2uJNwnX72VM2o&m=3__lJG7LXpAPrLcrgF9QSjTa30g5HOrAd8cD8GR8GfI&s=rKKmSQIMYjbkO11S-bLDg0oy_4APnsPzv5DF5CgAM9M&e= 

> >> 

> >> Given that the valid GID range for CFF is 0 through 65534 (65,535 glyphs), 

> >> my understanding is that "65536" should instead be "65535," unless CFF2 was 

> >> architected in a way that allows 65,536 glyphs. 

> >> 

> >> Regards... 

> >> 

> >> -- Ken 

> >> 

> >> 

> >> 

> >> 

> >> List archive: https://urldefense.proofpoint.com/v2/url?u=https-3A__nam04.safelinks.protection.outlook.com_-3Furl-3Dhttp-253A-252F-252Fwww.indx.co.uk-252Fbiglistarchive-252F-26data-3D02-257C01-257CLunde-2540adobe.com-257C2565f8ba25964978940f08d6bea0f6b5-257Cfa7b1b5a7b34438794aed2c178decee1-257C0-257C0-257C636905995905347520-26sdata-3Dgnb-252BEKvfzj-252FN1uvgeChFR5pmtz-252BZ-252FbQhpz9twUFIgKo-253D-26reserved-3D0&d=DwICaQ&c=euGZstcaTDllvimEN8b7jXrwqOf-v5A_CdpgnVfiiMM&r=jb2T9D8Np5j0t1X2JtGDVJ6FPFtBJQsSkOo2WUrCs2wDaDMjubx2uJNwnX72VM2o&m=3__lJG7LXpAPrLcrgF9QSjTa30g5HOrAd8cD8GR8GfI&s=YilDNnQ0idrpjrVwhJ70qCFriq9LOLU9zsOVda9MtM8&e= 

> >> List settings: https://urldefense.proofpoint.com/v2/url?u=https-3A__nam04.safelinks.protection.outlook.com_-3Furl-3Dhttp-253A-252F-252Fwww.indx.co.uk-252Fbiglistarchive-252F-253Fmode-253Dusersettings-26data-3D02-257C01-257CLunde-2540adobe.com-257C2565f8ba25964978940f08d6bea0f6b5-257Cfa7b1b5a7b34438794aed2c178decee1-257C0-257C0-257C636905995905347520-26sdata-3DdbMqHRzJuC5-252FaYI729DiD1sbIgLI9qpp-252FaovDOR-252BheI-253D-26reserved-3D0&d=DwICaQ&c=euGZstcaTDllvimEN8b7jXrwqOf-v5A_CdpgnVfiiMM&r=jb2T9D8Np5j0t1X2JtGDVJ6FPFtBJQsSkOo2WUrCs2wDaDMjubx2uJNwnX72VM2o&m=3__lJG7LXpAPrLcrgF9QSjTa30g5HOrAd8cD8GR8GfI&s=ZRuS7idRwsaYUZhH45uGiK2ZAic1bP5Juicj2gTASSM&e= 

> >> 

> >> subscribe: opentype-subscribe at indx.co.uk 

> >> unsubscribe: opentype-unsubscribe at indx.co.uk 

> >> messages: opentype-list at indx.co.uk 

> >> 

> >> 

> >> 

> > 

> > -- 

> > behdad 

> > https://urldefense.proofpoint.com/v2/url?u=https-3A__nam04.safelinks.protection.outlook.com_-3Furl-3Dhttp-253A-252F-252Fbehdad.org-252F-26data-3D02-257C01-257CLunde-2540adobe.com-257C2565f8ba25964978940f08d6bea0f6b5-257Cfa7b1b5a7b34438794aed2c178decee1-257C0-257C0-257C636905995905347520-26sdata-3DIhL9p-252FueyaSl45gs1aRJaL59YFaZKbg2KCBPyKqnq-252FI-253D-26reserved-3D0&d=DwICaQ&c=euGZstcaTDllvimEN8b7jXrwqOf-v5A_CdpgnVfiiMM&r=jb2T9D8Np5j0t1X2JtGDVJ6FPFtBJQsSkOo2WUrCs2wDaDMjubx2uJNwnX72VM2o&m=3__lJG7LXpAPrLcrgF9QSjTa30g5HOrAd8cD8GR8GfI&s=p21vorbQ2bMgS_jeramIzgyOJ2RuD7bKA3cITeS_x7M&e= 

> > 

> > 

> > 

> >> ****** Attachments to this email message have been removed ****** 

> > 

> > 

> > 

> > List archive: https://urldefense.proofpoint.com/v2/url?u=https-3A__nam04.safelinks.protection.outlook.com_-3Furl-3Dhttp-253A-252F-252Fwww.indx.co.uk-252Fbiglistarchive-252F-26data-3D02-257C01-257CLunde-2540adobe.com-257C2565f8ba25964978940f08d6bea0f6b5-257Cfa7b1b5a7b34438794aed2c178decee1-257C0-257C0-257C636905995905347520-26sdata-3Dgnb-252BEKvfzj-252FN1uvgeChFR5pmtz-252BZ-252FbQhpz9twUFIgKo-253D-26reserved-3D0&d=DwICaQ&c=euGZstcaTDllvimEN8b7jXrwqOf-v5A_CdpgnVfiiMM&r=jb2T9D8Np5j0t1X2JtGDVJ6FPFtBJQsSkOo2WUrCs2wDaDMjubx2uJNwnX72VM2o&m=3__lJG7LXpAPrLcrgF9QSjTa30g5HOrAd8cD8GR8GfI&s=YilDNnQ0idrpjrVwhJ70qCFriq9LOLU9zsOVda9MtM8&e= 

> > List settings: https://urldefense.proofpoint.com/v2/url?u=https-3A__nam04.safelinks.protection.outlook.com_-3Furl-3Dhttp-253A-252F-252Fwww.indx.co.uk-252Fbiglistarchive-252F-253Fmode-253Dusersettings-26data-3D02-257C01-257CLunde-2540adobe.com-257C2565f8ba25964978940f08d6bea0f6b5-257Cfa7b1b5a7b34438794aed2c178decee1-257C0-257C0-257C636905995905347520-26sdata-3DdbMqHRzJuC5-252FaYI729DiD1sbIgLI9qpp-252FaovDOR-252BheI-253D-26reserved-3D0&d=DwICaQ&c=euGZstcaTDllvimEN8b7jXrwqOf-v5A_CdpgnVfiiMM&r=jb2T9D8Np5j0t1X2JtGDVJ6FPFtBJQsSkOo2WUrCs2wDaDMjubx2uJNwnX72VM2o&m=3__lJG7LXpAPrLcrgF9QSjTa30g5HOrAd8cD8GR8GfI&s=ZRuS7idRwsaYUZhH45uGiK2ZAic1bP5Juicj2gTASSM&e= 

> > 

> > subscribe: opentype-subscribe at indx.co.uk 

> > unsubscribe: opentype-unsubscribe at indx.co.uk 

> > messages: opentype-list at indx.co.uk 

> > 

> > 

> 

> 

> 

> 

> 

> -- 

> behdad

> https://urldefense.proofpoint.com/v2/url?u=http-3A__behdad.org_&d=DwICaQ&c=euGZstcaTDllvimEN8b7jXrwqOf-v5A_CdpgnVfiiMM&r=jb2T9D8Np5j0t1X2JtGDVJ6FPFtBJQsSkOo2WUrCs2wDaDMjubx2uJNwnX72VM2o&m=3__lJG7LXpAPrLcrgF9QSjTa30g5HOrAd8cD8GR8GfI&s=VeBsTtZ-K0GSZbLbVK4pHuXkILh-mP5X23wt3hOyVrs&e=





------------------------------------
Posted by: Ken Lunde <lunde at adobe.com>
------------------------------------


------------------------------------

Yahoo Groups Links



-------------- next part --------------
A non-text attachment was scrubbed...
Name: not available
Type: application/x-ygp-stripped
Size: 428 bytes
Desc: m48xxx_14496-22 Proposed clarification CFF2 GID range.doc
URL: <https://lists.aau.at/pipermail/mpeg-otspec/attachments/20190520/87def8ea/attachment.bin>

More information about the mpeg-otspec mailing list