On 2/16/2018 10:20 AM, Richard Wordingham via Unicode wrote:
On Fri, 16 Feb 2018 08:22:23 -0800
Ken Whistler via Unicode <[email protected]> wrote:
On 2/16/2018 8:00 AM, Richard Wordingham via Unicode wrote:
A more portable solution for ideographs is to render an Ideographic
Description Sequences (IDS) as approximations to the characters they
describe. The Unicode Standard carefully does not prohibit so
doing, and a similar scheme is being developed for blocks of
Egyptian Hieroglyphs, and has been proposed for Mayan as well.
A point of clarification: The IDC's (ideographic description
characters) are explicitly *not* format controls. They are visible
graphic symbols that sit visibly in text.
That doesn't square well with, "An implementation may render a valid
Ideographic Description Sequence either by rendering the individual
characters separately or by parsing the Ideographic Description
Sequence and drawing the ideograph so described." (TUS 10.0 p704, in
Section 18.2)
Should we ask t make the default behavior (visible IDS characters) more
explicit?
I don't mind allowing the other as an option (it's kind of the reverse
of the "show invisible"
mode, which we also allow, but for which we do have a clear default).
The reason for comparison with Egyptian quadrat controls is the scaling
issue. The thickness of brush strokes should be consistent across the
ideograph, which increases the complexity of a font that parses the
descriptions. Outline hieroglyphic quadrats have the same problem.
However, as I said before, there is a good argument for rendering an
IDS inelegantly.
Richard.
