[luatex] an issue with \rpcode

[Hans Hagen]

On 10/11/2014 5:07 PM, Mittelbach, Frank wrote:
> while trying to make Taco's linebreaker code I came across some behavior
> that I found rather weird
>
> in essense it looks as if \rpcode is not ending up in the char table
> unless \lpcode for the same char is set first (and non-zero)
>
> \pdfprotrudechars=1
>
> %\lpcode\font 50 = 1
> \rpcode\font 50 = 200
> \efcode\font 50 = 333
>
> \directlua{
> local function FMItable (name,t)
>      print ("---- looking at table ", name, tostring(t))
>        for k, v in pairs(t) do
>      print("    ", k,"=", tostring(v))
>        end
>      print("----------------")
> end
>   FMItable("char 50",font.fonts[font.current()].characters[50])
> }
>
> \bye
>
> --------------------
>
> if you uncomment the lpcode line then both values show up. But what is
> puzzling me even more is that if I change the values and then run this
> directlua bit again, nothing changes (could of course be that I should
> define FMItable differently but ...
>
> anybody any clue?

sure .. the table that you see is a cached one and if you change a rp 
value after the font definition it is not reflected in there

see page 158 of luatex manual : cache field in passed tfm data tbale

keep in mind that normally one will only set the protrusion values when 
a font is loaded because once a font is used they are frozen

(currently these values are em related but at some point they might 
become glyph width related)

\starttext

\directlua{
     function fonts.constructors.aftercopyingcharacters(target,original)
         target.cache = "renew"
     end
}

\pdfprotrudechars=1

\font\foo = LMRoman10-Regular*default,quality at 12.3pt

\foo

\lpcode\foo 45 = 2000\relax
\rpcode\foo 45 = 2000\relax
\efcode\foo 45 = 4000\relax

\directlua{
     print("data at tex end")
     inspect(font.fonts              [font.current()].characters[45])
     print("original passed data")
     inspect(fonts.hashes.identifiers[font.current()].characters[45])
}

test

\stoptext


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