[luatex] protect_glyph

Taco Hoekwater taco at elvenkind.com
Mon Jul 4 13:35:13 CEST 2011

On 07/04/2011 12:48 PM, luigi scarso wrote:
> On Mon, Jul 4, 2011 at 12:24 PM, Patrick Gundlach<patrick at gundla.ch>  wrote:
>>> and why 256 is important for it ?
>> good question. The bit field has only 4 bits, so 256 makes no sense for me.
> 5 bits, see luatexdir/tex/texnodes.h

protect_glyph/unprotect_glyph is a bit of an odd thing that was
added as a speedup (helper) for lua node processing in ConTeXt.
It has its uses, but nevertheless its existence is debatable, and
we may come up with something else in the end. (it exists to
separate characters that have been processed into glyphs from
glyphs there added directly as glyphs, the value '256' is just
to get some distance away from bit 5).

>> BTW: there seems to be a contradiction in the manual.
> yes, it seems so.
>> bit meaning
>> 0 character
>> 1 glyph
>> 2 ligature
>> 3 ghost
>> 4 left
>> 5 right

Fixed that table.

Best wishes,

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