- From: John Hudson <john@tiro.ca>
- Date: Mon, 19 Aug 2019 10:12:26 -0700
- To: Roderick Sheeter <rsheeter@google.com>, Garret Rieger <grieger@google.com>
- Cc: "Myles C. Maxfield" <mmaxfield@apple.com>, "Levantovsky, Vladimir" <Vladimir.Levantovsky@monotype.com>, Jonathan Kew <jfkthame@gmail.com>, "public-webfonts-wg@w3.org" <public-webfonts-wg@w3.org>
On 19082019 10:00 am, Roderick Sheeter wrote: > <style > /* font face for Bengali, unicode-range includes danda */ > /* font face for Telugu, unicode-range includes danda */ > </style> > <body> > [Bengali text that uses danda ... which will flip to the Telugu font > for the danda (and any other shared character)] > </body> > > In the sketch above the danda for Telugu is always used because it's > the last declared and thus the highest priority supporting face. > Rendering Bengali text will use the Telugu danda and snap any layout > features involving it. Ouch. The danda and double danda characters require script-specific glyph forms that coordinate with the proportions and weights of the individual scripts. For the Bengali, you would really want to display the Bengali danda glyphs*, not the Telugu, which are likely to be too short and too light. * Also worth noting that Bengali has two traditional forms of danda: a straight one that can often be shared with the Devanagari set, and one with ball terminals that is used in traditional poetry setting. In our Bengali fonts, we treat this poetic form as a stylistic glyph variant of the Bengali danda glyphs, so there is even more reason to ensure that the danda of another glyph is substituted. Of course, all this could have been avoided if Unicode had opted to encode script-specific danda characters, but as it is we need mechanisms to control the form, either by always getting the glyph from a script-specific font or checking <locl> OTL feature substitutions for individual scripts. What about things like the Vedic extension characters, subsets of which are used with a variety of Indic scripts, but also require script-specific forms, which sometimes are quite distinctive and subject to different shaping behaviour in particular scripts. JH -- John Hudson Tiro Typeworks Ltd www.tiro.com Salish Sea, BC tiro@tiro.com NOTE: In the interests of productivity, I am currently dealing with email on only two days per week, usually Monday and Thursday unless this schedule is disrupted by travel. If you need to contact me urgently, please use some other method of communication. Thank you.
Received on Monday, 19 August 2019 17:12:53 UTC