pdfadjustinterwordglue in LuaTeX

pdfadjustinterwordglue.tex

\ifdefined\directlua

\csname newcount\endcsname\pdfadjustinterwordglue

\begingroup
\catcode`\^^M=12
\directlua{
local subtypes = node.subtypes("glue")

local knbscode = {}

local fontid = token.create("fontid")

function set_knbscode(field)
    token.put_next(fontid)
    local fid = token.scan_int()
    local chr = token.scan_int()
    local str = token.scan_string()

    knbscode[fid] = knbscode[fid] or {}
    knbscode[fid][chr] = knbscode[fid][chr] or {}
    local int = string.gsub(str,"=","")
    knbscode[fid][chr][field] = tonumber(int)
end

function get_knbscode(field)
    token.put_next(fontid)
    local fid = token.scan_int()
    local chr = token.scan_int()

    knbscode[fid] = knbscode[fid] or {}
    knbscode[fid][chr] = knbscode[fid][chr] or {}
    tex.sprint([[\numexpr]] .. (knbscode[fid][chr][field] or 0) .. [[\relax]])
end

local microtype_spacing = function(head, tail)
    head, tail, success = node.kerning(head, tail)
    if tex.count.pdfadjustinterwordglue > 0 then
        for space in node.traverse_id(node.id("glue"), head) do
            if subtypes[space.subtype] == "spaceskip" then
                local prev = node.prev(space)
                if prev.id == node.id("glyph") then
                    local knbs = knbscode[prev.font]
                    if knbs and knbs[prev.char] then
                        local f = font.getfont(prev.font)
                        local em = f.parameters.quad

                        local width = knbs[prev.char].width or 0
                        local stretch = knbs[prev.char].stretch or 0
                        local shrink = knbs[prev.char].shrink or 0

                        local glue = node.new(node.id("glue"))
                        glue.width = width*em/1000
                        glue.stretch = stretch*em/1000
                        glue.shrink = shrink*em/1000

                        head = node.insert_before(head, space, glue)
                    end
                end
            end
        end
    end
end

callback.register("kerning", microtype_spacing, "microtype_spacing")
}%
\endgroup

\protected\def\knbscode{\directlua{set_knbscode("width")}}
\protected\def\stbscode{\directlua{set_knbscode("stretch")}}
\protected\def\shbscode{\directlua{set_knbscode("shrink")}}

\def\theknbscode{\the\directlua{get_knbscode("width")}}
\def\thestbscode{\the\directlua{get_knbscode("stretch")}}
\def\theshbscode{\the\directlua{get_knbscode("shrink")}}

\else

\def\theknbscode{\the\knbscode}
\def\thestbscode{\the\stbscode}
\def\theshbscode{\the\shbscode}

\fi

\pdfadjustinterwordglue=1

\knbscode\font`r=1100
\stbscode\font`r=10
\shbscode\font`r=10

\knbscode\font`r 1100
\stbscode\font`r 10
\shbscode\font`r 10

\theknbscode\font`r
\thestbscode\font`r
\theshbscode\font`r

\knbscode\font`m=\theknbscode\font`r\relax

\the\numexpr 1+2\relax

\input lorem

\bye