>> In TrueType/OpenType, glyphs don't have to be mapped (assigned to
>> code points).
>
>This is a myth that I hope to see eradicated as soon as possible.
Marco, you are generating a myth that I hope not to see catch on. James is
absolutely right.
>The only possible way to display Unicode is to map characters to glyphs
>according to a set of rules. There is no magic that can avoid this;
existing
>"smart font" technologies are simply good implementations of this mapping
>process.
>
>What does the 'cmap' table do if not converting code points to another set
>of numbers? Letting apart the fact that the second domain (the glyph
>indexes) is not standardized and not uniform across different fonts, what
is
>the difference --in terms of performance-- with using pseudo-Unicode
scalars
>as glyph indexes?
The biggest problem is that you can't necessarily know what glyph ID any
glyph will be assigned to until the font is generated. When the term
"encoding" is used in relation to fonts, the conventional practice as far
as I know is to us it in reference to the input side of the cmap table
only.
>> Many fonts have glyphs which the user can't access
>> directly, this is especially true now with OpenType.
>
>Sorry, I miss the implication of this.
He means, that are not accessible via the cmap, not that they can't be
displayed using a combination of cmap and subsequent lookup tables.
>> No. The new cmap supports more than double-byte in order to access
>> non-BMP encodings. The Glyph IDs (the number/order of the glyphs
>> in a font) remain locked at 65536 max. Unfortunately this isn't
>> expected to change, last I heard.
>
>What a pity!
>
>Maybe it could be one more reason to come up with a small GNU renderer
that
>supports 0x1000000 glyphs: the moral let-down could move the big ones to
>update their tables. :-)
Megafonts like that generally drain system resources and are not considered
A Good Idea.
- Peter
---------------------------------------------------------------------------
Peter Constable
Non-Roman Script Initiative, SIL International
7500 W. Camp Wisdom Rd., Dallas, TX 75236, USA
Tel: +1 972 708 7485
E-mail: <peter_constable@sil.org>
This archive was generated by hypermail 2.1.2 : Fri Jul 06 2001 - 00:17:16 EDT