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tex-compiler/texmf-dist/tex/luatex/luaotfload/luaotfload-harf-plug.lua

1027 lines
35 KiB

-----------------------------------------------------------------------
-- FILE: luaotfload-harf-plug.lua
-- DESCRIPTION: part of luaotfload / HarfBuzz / fontloader plugin
-----------------------------------------------------------------------
do -- block to avoid to many local variables error
local ProvidesLuaModule = {
name = "luaotfload-harf-plug",
version = "3.14", --TAGVERSION
date = "2020-05-06", --TAGDATE
description = "luaotfload submodule / database",
license = "GPL v2.0",
author = "Khaled Hosny, Marcel Krüger",
copyright = "Luaotfload Development Team",
}
if luatexbase and luatexbase.provides_module then
luatexbase.provides_module (ProvidesLuaModule)
end
end
local hb = luaotfload.harfbuzz
local assert = assert
local next = next
local tonumber = tonumber
local type = type
local format = string.format
local open = io.open
local tableinsert = table.insert
local tableremove = table.remove
local ostmpname = os.tmpname
local osremove = os.remove
local direct = node.direct
local tonode = direct.tonode
local todirect = direct.todirect
local traverse = direct.traverse
local insertbefore = direct.insert_before
local insertafter = direct.insert_after
local protectglyph = direct.protect_glyph
local newnode = direct.new
local freenode = direct.free
local copynode = direct.copy
local removenode = direct.remove
local copynodelist = direct.copy_list
local ischar = direct.is_char
local uses_font = direct.uses_font
local getattrs = direct.getattributelist
local setattrs = direct.setattributelist
local getchar = direct.getchar
local setchar = direct.setchar
local getdir = direct.getdir
local setdir = direct.setdir
local getdisc = direct.getdisc
local setdisc = direct.setdisc
local getfont = direct.getfont
local getdata = direct.getdata
local setdata = direct.setdata
local getfont = direct.getfont
local setfont = direct.setfont
local getfield = direct.getfield
local setfield = direct.setfield
local getid = direct.getid
local getkern = direct.getkern
local setkern = direct.setkern
local getnext = direct.getnext
local setnext = direct.setnext
local getoffsets = direct.getoffsets
local setoffsets = direct.setoffsets
local getproperty = direct.getproperty
local setproperty = direct.setproperty
local getprev = direct.getprev
local setprev = direct.setprev
local getsubtype = direct.getsubtype
local setsubtype = direct.setsubtype
local getwidth = direct.getwidth
local setwidth = direct.setwidth
local is_char = direct.is_char
local tail = direct.tail
local properties = direct.get_properties_table()
local imgnode = img.node
local disc_t = node.id("disc")
local glue_t = node.id("glue")
local glyph_t = node.id("glyph")
local dir_t = node.id("dir")
local kern_t = node.id("kern")
local localpar_t = node.id("local_par")
local whatsit_t = node.id("whatsit")
local pdfliteral_t = node.subtype("pdf_literal")
local explicitdisc_t = 1
local fontkern_t = 0
local italiccorr_t = 3
local regulardisc_t = 3
local spaceskip_t = 13
local dir_ltr = hb.Direction.new("ltr")
local dir_rtl = hb.Direction.new("rtl")
local fl_unsafe = hb.Buffer.GLYPH_FLAG_UNSAFE_TO_BREAK
local startactual_p = "luaotfload_startactualtext"
local endactual_p = "luaotfload_endactualtext"
local empty_table = {}
-- "Copy" properties as done by LuaTeX: Make old properties metatable
local function copytable(old)
local new = {}
for k, v in next, old do
if type(v) == "table" then v = copytable(v) end
new[k] = v
end
setmetatable(new, getmetatable(old))
return new
end
-- Set and get properties.
local function setprop(n, prop, value)
local props = properties[n]
if not props then
props = {}
properties[n] = props
end
props[prop] = value
end
local function inherit(t, base, properties)
local n = newnode(t)
setattrs(n, getattrs(base))
if properties then
setproperty(n, setmetatable({}, {__index = properties}))
end
return n
end
-- New kern node of amount `v`, inheriting the properties/attributes of `n`.
local function newkern(v, n)
local kern = inherit(kern_t, n, getproperty(n))
setkern(kern, v)
return kern
end
local function insertkern(head, current, kern, rtl)
if rtl then
head = insertbefore(head, current, kern)
else
head, current = insertafter(head, current, kern)
end
return head, current
end
-- Convert list of integers to UTF-16 hex string used in PDF.
local function to_utf16_hex(uni)
if uni < 0x10000 then
return format("%04X", uni)
else
uni = uni - 0x10000
local hi = 0xD800 + (uni // 0x400)
local lo = 0xDC00 + (uni % 0x400)
return format("%04X%04X", hi, lo)
end
end
local process
local function itemize(head, fontid, direction)
local fontdata = font.getfont(fontid)
local hbdata = fontdata and fontdata.hb
local spec = fontdata and fontdata.specification
local options = spec and spec.features.raw
local runs, codes = {}, {}
local dirstack = {}
local currdir = direction or "TLT"
local lastskip, lastdir = true
local lastrun = {}
for n, id, subtype in direct.traverse(head) do
local code = 0xFFFC -- OBJECT REPLACEMENT CHARACTER
local skip = lastskip
local props = properties[n]
if props and props.zwnj then
code = 0x200C
-- skip = false -- Not sure about this, but lastskip should be a bit faster
elseif id == glyph_t then
if is_char(n) and getfont(n) == fontid then
code = getchar(n)
skip = false
else
skip = true
end
elseif id == glue_t and subtype == spaceskip_t then
code = 0x0020 -- SPACE
elseif id == disc_t then
if uses_font(n, fontid) then
code = 0x00AD -- SOFT HYPHEN
skip = false
else
skip = true
end
elseif id == dir_t then
local dir = getdir(n)
if dir:sub(1, 1) == "+" then
-- Push the current direction to the stack.
tableinsert(dirstack, currdir)
currdir = dir:sub(2)
else
assert(currdir == dir:sub(2))
-- Pop the last direction from the stack.
currdir = tableremove(dirstack)
end
elseif id == localpar_t then
currdir = getdir(n)
end
codes[#codes + 1] = code
if lastdir ~= currdir or lastskip ~= skip then
lastrun.after = n
lastrun = {
start = #codes,
len = 1,
font = fontid,
dir = currdir == "TRT" and dir_rtl or dir_ltr,
skip = skip,
codes = codes,
}
runs[#runs + 1] = lastrun
lastdir, lastskip = currdir, skip
else
lastrun.len = lastrun.len + 1
end
end
return runs
end
-- Check if it is not safe to break before this glyph.
local function unsafetobreak(glyph)
return glyph
and glyph.flags
and glyph.flags & fl_unsafe
end
local shape
-- Make s a sub run, used by discretionary nodes.
local function makesub(run, codes, nodelist)
local subrun = {
start = 1,
len = #codes,
font = run.font,
dir = run.dir,
fordisc = true,
node = nodelist,
codes = codes,
}
local glyphs
if nodelist == 0 then -- FIXME: This shouldn't happen
nodelist = nil
end
nodelist, nodelist, glyphs = shape(nodelist, nodelist, subrun)
return { glyphs = glyphs, run = subrun, head = nodelist }
end
local function printnodes(label, head, after)
after = tonode(after)
for n in node.traverse(tonode(head)) do
if n == after then return end
print(label, n, n.font or '', n.char or '')
local pre, post, rep = getdisc(todirect(n))
if pre then
printnodes(label .. '<', pre)
end
if post then
printnodes(label .. '>', post)
end
if rep then
printnodes(label .. '=', rep)
end
end
end
-- Main shaping function that calls HarfBuzz, and does some post-processing of
-- the output.
function shape(head, firstnode, run)
local node = firstnode
local codes = run.codes
local offset = run.start
local nodeindex = offset
run.start = offset
local len = run.len
local fontid = run.font
local dir = run.dir
local fordisc = run.fordisc
local cluster = offset - 2
local fontdata = font.getfont(fontid)
local hbdata = fontdata.hb
local spec = fontdata.specification
local features = spec.hb_features
local options = spec.features.raw
local hbshared = hbdata.shared
local hbfont = hbshared.font
local lang = spec.language
local script = spec.script
local shapers = options.shaper and { options.shaper } or {}
local buf = hb.Buffer.new()
if buf.set_flags then
buf:set_flags(hbdata.buf_flags)
end
buf:set_direction(dir)
buf:set_script(script)
buf:set_language(lang)
buf:set_cluster_level(buf.CLUSTER_LEVEL_MONOTONE_CHARACTERS)
buf:add_codepoints(codes, offset - 1, len)
local hscale = hbdata.hscale
local vscale = hbdata.vscale
hbfont:set_scale(hscale, vscale)
do
features = table.merged(features) -- We don't want to modify the global features
local current_features = {}
local n = node
for i = offset-1, offset+len-2 do
local props = properties[n] or empty_table
if props then
local local_feat = props.glyph_features or empty_table
if local_feat then
for tag, value in next, current_features do
local loc = local_feat[tag]
loc = loc ~= nil and (tonumber(loc) or (loc and 1 or 0)) or nil
if value.value ~= loc then -- This includes loc == nil
value._end = i
features[#features + 1] = value
current_features[tag] = nil
end
end
for tag, value in next, local_feat do
if not current_features[tag] then
local feat = hb.Feature.new(tag)
feat.value = tonumber(value) or (value and 1 or 0)
feat.start = i
current_features[tag] = feat
end
end
end
end
n = getnext(n)
end
for _, feat in next, current_features do
features[#features + 1] = feat
end
end
if hb.shape_full(hbfont, buf, features, shapers) then
-- The engine wants the glyphs in logical order, but HarfBuzz outputs them
-- in visual order, so we reverse RTL buffers.
if dir:is_backward() then buf:reverse() end
local glyphs = buf:get_glyphs()
local i = 0
while i < #glyphs do
i = i + 1
local glyph = glyphs[i]
-- Calculate the Unicode code points of this glyph. If cluster did not
-- change then this is a glyph inside a complex cluster and will be
-- handled with the start of its cluster.
if cluster ~= glyph.cluster then
cluster = glyph.cluster
for i = nodeindex, cluster do node = getnext(node) end
nodeindex = cluster + 1
local hex = ""
local str = ""
local nextcluster
for j = i+1, #glyphs do
nextcluster = glyphs[j].cluster
if cluster ~= nextcluster then
glyph.nglyphs = j - i
goto NEXTCLUSTERFOUND -- break
end
end -- else -- only executed if the loop reached the end without
-- finding another cluster
nextcluster = offset + len - 1
glyph.nglyphs = #glyphs + 1 - i
::NEXTCLUSTERFOUND:: -- end
glyph.nextcluster = nextcluster
do
local node = node
for j = cluster,nextcluster-1 do
local id = getid(node)
if id == glyph_t or (id == glue_t and getsubtype(node) == spaceskip_t) then
local code = codes[j + 1]
hex = hex..to_utf16_hex(code)
str = str..utf8.char(code)
end
end
glyph.tounicode = hex
glyph.string = str
end
if not fordisc then
local discindex = nil
local disc = node
for j = cluster + 1, nextcluster do
local props = properties[disc]
if (not (props and props.zwnj)) and getid(disc) == disc_t then
discindex = j
break
end
disc = getnext(disc)
end
if discindex then
-- Discretionary found.
local startindex, stopindex = nil, nil
local startglyph, stopglyph = nil, nil
-- Find the previous glyph that is safe to break at.
local startglyph = i
while startglyph > 1
and codes[glyphs[startglyph - 1].cluster + 1] ~= 0x20
and codes[glyphs[startglyph - 1].cluster + 1] ~= 0xFFFC
and unsafetobreak(glyphs[startglyph]) do
startglyph = startglyph - 1
end
-- Get the corresponding character index.
startindex = glyphs[startglyph].cluster + 1
-- Find the next glyph that is safe to break at.
stopglyph = i + 1
local lastcluster = glyphs[i].cluster
while stopglyph <= #glyphs
and codes[glyphs[stopglyph].cluster + 1] ~= 0x20
and codes[glyphs[stopglyph].cluster + 1] ~= 0xFFFC
and (unsafetobreak(glyphs[stopglyph])
or lastcluster == glyphs[stopglyph].cluster) do
lastcluster = glyphs[stopglyph].cluster
stopglyph = stopglyph + 1
end
stopindex = stopglyph <= #glyphs and glyphs[stopglyph].cluster + 1
or offset + len
local startnode, stopnode = node, node
for j=nodeindex - 1, startindex, -1 do
startnode = getprev(startnode)
end
for j=nodeindex + 1, stopindex do
stopnode = getnext(stopnode)
end
glyphs[startglyph] = glyph
glyph.cluster = startindex - 1
glyph.nextcluster = startindex
for j = stopglyph, #glyphs do
local glyph = glyphs[j]
glyph.cluster = glyph.cluster - (stopindex - startindex) + 1
end
len = len - (stopindex - startindex) + 1
table.move(glyphs, stopglyph, #glyphs + stopglyph - startglyph - 1, startglyph + 1)
local subcodes, subindex = {}
do
local node = startnode
while node ~= stopnode do
if node == disc then
subindex = #subcodes
startindex = startindex + 1
node = getnext(node)
elseif getid(node) == disc_t then
local oldnode = node
startnode, node = removenode(startnode, node)
freenode(oldnode)
tableremove(codes, startindex)
else
subcodes[#subcodes + 1] = tableremove(codes, startindex)
node = getnext(node)
end
end
end
local pre, post, rep, lastpre, lastpost, lastrep = getdisc(disc, true)
local precodes, postcodes, repcodes = {}, {}, {}
table.move(subcodes, 1, subindex, 1, repcodes)
for n, id, subtype in traverse(rep) do
repcodes[#repcodes + 1] = getfont(n) == fontid and getchar(n) or 0xFFFC
end
table.move(subcodes, subindex + 1, #subcodes, #repcodes + 1, repcodes)
table.move(subcodes, 1, subindex, 1, precodes)
for n, id, subtype in traverse(pre) do
precodes[#precodes + 1] = getfont(n) == fontid and getchar(n) or 0xFFFC
end
for n, id, subtype in traverse(post) do
postcodes[#postcodes + 1] = getfont(n) == fontid and getchar(n) or 0xFFFC
end
table.move(subcodes, subindex + 1, #subcodes, #postcodes + 1, postcodes)
if startnode ~= disc then
local newpre = copynodelist(startnode, disc)
setnext(tail(newpre), pre)
pre = newpre
end
if post then
setnext(lastpost, copynodelist(getnext(disc), stopnode))
else
post = copynodelist(getnext(disc), stopnode)
end
if startnode ~= disc then
local predisc = getprev(disc)
setnext(predisc, rep)
setprev(rep, predisc)
if firstnode == startnode then
firstnode = disc
end
if startnode == head then
head = disc
else
local before = getprev(startnode)
setnext(before, disc)
setprev(disc, before)
end
setprev(startnode, nil)
rep = startnode
lastrep = lastrep or predisc
end
if getnext(disc) ~= stopnode then
setnext(getprev(stopnode), nil)
setprev(stopnode, disc)
setprev(getnext(disc), lastrep)
setnext(lastrep, getnext(disc))
rep = rep or getnext(disc)
setnext(disc, stopnode)
end
glyph.replace = makesub(run, repcodes, rep)
glyph.pre = makesub(run, precodes, pre)
glyph.post = makesub(run, postcodes, post)
i = startglyph
node = disc
cluster = glyph.cluster
nodeindex = cluster + 1
end
end
end
end
return head, firstnode, glyphs, run.len - len
end
return head, firstnode, {}, 0
end
local function color_to_rgba(color)
local r = color.red / 255
local g = color.green / 255
local b = color.blue / 255
local a = color.alpha / 255
if a ~= 1 then
-- XXX: alpha
return format('%s %s %s rg', r, g, b)
else
return format('%s %s %s rg', r, g, b)
end
end
-- Cache of color glyph PNG data for bookkeeping, only because I couldn’t
-- figure how to make the engine load the image from the binary data directly.
local pngcache = {}
local pngcachefiles = {}
local function cachedpng(data)
local hash = md5.sumhexa(data)
local i = pngcache[hash]
if not i then
local path = ostmpname()
pngcachefiles[#pngcachefiles + 1] = path
open(path, "wb"):write(data):close()
-- local file = open(path, "wb"):write():close()
-- file:write(data)
-- file:close()
i = img.scan{filename = path}
pngcache[hash] = i
end
return i
end
local function get_png_glyph(gid, fontid, characters, haspng)
return gid
end
local push_cmd = { "push" }
local pop_cmd = { "pop" }
local nop_cmd = { "nop" }
--[[
In the following, "text" actually refers to "font" mode and not to "text"
mode. "font" mode is called "text" inside of virtual font commands (don't
ask me why, but the LuaTeX source does make it clear that this is intentional)
and behaves mostly like "page" (especially it does not enter a "BT" "ET"
block) except that it always resets the current position to the origin.
This is necessary to ensure that the q/Q pair does not interfere with TeX's
position tracking.
]]
local save_cmd = { "pdf", "text", "q" }
local restore_cmd = { "pdf", "text", "Q" }
-- Convert glyphs to nodes and collect font characters.
local function tonodes(head, node, run, glyphs)
local nodeindex = run.start
local dir = run.dir
local fontid = run.font
local fontdata = font.getfont(fontid)
local space = fontdata.parameters.space
local characters = fontdata.characters
local hbdata = fontdata.hb
local hfactor = (fontdata.extend or 1000) / 1000
local palette = hbdata.palette
local hbshared = hbdata.shared
local hbface = hbshared.face
local nominals = hbshared.nominals
local hbfont = hbshared.font
local fontglyphs = hbshared.glyphs
local gid_offset = hbshared.gid_offset
local rtl = dir:is_backward()
local lastprops
local scale = hbdata.scale
local haspng = hbshared.haspng
local fonttype = hbshared.fonttype
local nextcluster
for i, glyph in ipairs(glyphs) do
if glyph.cluster + 1 >= nodeindex then -- Reached a new cluster
nextcluster = glyph.nextcluster
assert(nextcluster)
for j = nodeindex, glyph.cluster do
local oldnode = node
head, node = removenode(head, node)
freenode(oldnode)
end
lastprops = getproperty(node)
nodeindex = glyph.cluster + 1
elseif nextcluster + 1 == nodeindex then -- Oops, we went too far
nodeindex = nodeindex - 1
local new = inherit(glyph_t, getprev(node), lastprops)
setfont(new, fontid)
head, node = insertbefore(head, node, new)
end
local gid = glyph.codepoint
local char = nominals[gid] or gid_offset + gid
local id = getid(node)
if glyph.replace then
-- For discretionary the glyph itself is skipped and a discretionary node
-- is output in place of it.
local rep, pre, post = glyph.replace, glyph.pre, glyph.post
setdisc(node, tonodes(pre.head, pre.head, pre.run, pre.glyphs),
tonodes(post.head, post.head, post.run, post.glyphs),
tonodes(rep.head, rep.head, rep.run, rep.glyphs))
node = getnext(node)
nodeindex = nodeindex + 1
elseif glyph.skip then
local oldnode = node
head, node = removenode(head, node)
freenode(oldnode)
nodeindex = nodeindex + 1
else
if lastprops and lastprops.zwnj and nodeindex == glyph.cluster + 1 then
elseif id == glyph_t then
local done
local fontglyph = fontglyphs[gid]
local character = characters[char]
if not character.commands then
if palette then
local layers = fontglyph.layers
if layers == nil then
layers = hbface:ot_color_glyph_get_layers(gid) or false
fontglyph.layers = layers
end
if layers then
local cmds = {} -- Every layer will add 5 cmds
local prev_color = nil
for j = 1, #layers do
local layer = layers[j]
local layerchar = characters[gid_offset + layer.glyph]
if layerchar.height > character.height then
character.height = layerchar.height
end
if layerchar.depth > character.depth then
character.depth = layerchar.depth
end
-- color_index has a special value, 0x10000, that mean use text
-- color, we don’t check for it here explicitly since we will
-- get nil anyway.
local color = palette[layer.color_index]
cmds[5*j - 4] = (color and not prev_color) and save_cmd or nop_cmd
cmds[5*j - 3] = prev_color == color and nop_cmd or (color and {"pdf", "page", color_to_rgba(color)} or restore_cmd)
cmds[5*j - 2] = push_cmd
cmds[5*j - 1] = {"char", layer.glyph + gid_offset}
cmds[5*j] = pop_cmd
fontglyphs[layer.glyph].used = true
prev_color = color
end
cmds[#cmds + 1] = prev_color and restore_cmd
if not character.colored then
local coloredcharacter = {}
for k,v in next, character do
coloredcharacter[k] = v
end
coloredcharacter.commands = cmds
local newcharacters = {[gid + 0x130000] = coloredcharacter}
characters[gid + 0x130000] = coloredcharacter
if char ~= gid + gid_offset then
newcharacters[char] = coloredcharacter
characters[char] = coloredcharacter
character.colored = char
else
character.colored = gid + 0x130000
end
font.addcharacters(fontid, {characters = newcharacters})
end
char = character.colored
character = characters[char]
end
end
if haspng then
local pngglyph = character.pngglyph
if pngglyph == nil then
local pngblob = hbfont:ot_color_glyph_get_png(gid)
if pngblob then
local glyphimg = cachedpng(pngblob:get_data())
local pngchar = { }
for k,v in next, character do
pngchar[k] = v
end
local i = img.copy(glyphimg)
i.width = character.width
i.depth = 0
i.height = character.height + character.depth
pngchar.commands = fonttype and {
{"push"}, {"char", gid_offset + gid}, {"pop"},
{"down", character.depth}, {"image", i}
} or { {"down", character.depth}, {"image", i} }
if not nominals[gid] then
char = 0x130000 + gid
end
characters[char] = pngchar
pngglyph = char
font.addcharacters(fontid, {characters = {[char] = pngchar}})
end
character.pngglyph = pngglyph
end
if pngglyph then
char = pngglyph
elseif not fonttype then
-- Color bitmap font with no glyph outlines (like Noto
-- Color Emoji) but has no bitmap for current glyph (most likely
-- `.notdef` glyph). The engine does not know how to embed such
-- fonts, so we don’t want them to reach the backend as it will cause
-- a fatal error. We use `nullfont` instead. That is a hack, but I
-- think it is good enough for now. We could make the glyph virtual
-- with empty commands suh that LuaTeX ignores it, but we still want
-- a missing glyph warning.
-- We insert the glyph node and move on, no further work is needed.
setfont(node, 0)
done = true
end
end
end
if not done then
local oldcharacter = characters[getchar(node)]
-- If the glyph index of current font character is the same as shaped
-- glyph, keep the node char unchanged. Helps with primitives that
-- take characters as input but actually work on glyphs, like
-- `\rpcode`.
if not oldcharacter then
if gid == 0 then
local new = copynode(node)
head, node = insertafter(head, node, new)
end
setchar(node, char)
elseif character.commands
or character.index ~= oldcharacter.index then
setchar(node, char)
end
local xoffset = (rtl and -glyph.x_offset or glyph.x_offset) * scale
local yoffset = glyph.y_offset * scale
setoffsets(node, xoffset, yoffset)
fontglyph.used = fonttype and true
-- The engine will use this string when printing a glyph node e.g. in
-- overfull messages, otherwise it will be trying to print our
-- invalid pseudo Unicode code points.
-- If the string is empty it means this glyph is part of a larger
-- cluster and we don’t to print anything for it as the first glyph
-- in the cluster will have the string of the whole cluster.
local props = properties[node]
if not props then
props = {}
properties[node] = props
end
props.glyph_info = glyph.string or ""
-- Handle PDF text extraction:
-- * Find how many characters in this cluster and how many glyphs,
-- * If there is more than 0 characters
-- * One glyph: one to one or one to many mapping, can be
-- represented by font’s /ToUnicode
-- * More than one: many to one or many to many mapping, can be
-- represented by /ActualText spans.
-- * If there are zero characters, then this glyph is part of complex
-- cluster that will be covered by an /ActualText span.
local tounicode = glyph.tounicode
if tounicode then
if glyph.nglyphs == 1
and not character.commands
and not fontglyph.tounicode then
fontglyph.tounicode = tounicode
elseif character.commands or tounicode ~= fontglyph.tounicode then
setprop(node, startactual_p, tounicode)
glyphs[i + glyph.nglyphs - 1].endactual = true
end
end
if glyph.endactual then
setprop(node, endactual_p, true)
end
local x_advance = glyph.x_advance
local width = fontglyph.width * hfactor
if width ~= x_advance then
-- The engine always uses the glyph width from the font, so we need
-- to insert a kern node if the x advance is different.
local kern = newkern((x_advance - width) * scale, node)
head, node = insertkern(head, node, kern, rtl)
end
end
elseif id == glue_t and getsubtype(node) == spaceskip_t then
-- If the glyph advance is different from the font space, then a
-- substitution or positioning was applied to the space glyph changing
-- it from the default. We try to maintain as much as possible from the
-- original value because we assume that we want to keep spacefactors and
-- assume that we got mostly positioning applied. TODO: Handle the case that
-- we became a glyph in the process.
-- We are intentionally not comparing with the existing glue width as
-- spacing after the period is larger by default in TeX.
local width = glyph.x_advance * scale
-- if space > width + 2 or width > space + 2 then
if space ~= width then
setwidth(node, getwidth(node) - space + width)
-- setfield(node, "stretch", width / 2)
-- setfield(node, "shrink", width / 3)
end
elseif id == kern_t and getsubtype(node) == italiccorr_t then
-- If this is an italic correction node and the previous node is a
-- glyph, update its kern value with the glyph’s italic correction.
local prevchar, prevfontid = ischar(getprev(node))
if prevfontid == fontid and prevchar and prevchar > 0 then
local italic = characters[prevchar].italic
if italic then
setkern(node, italic)
end
end
end
node = getnext(node)
nodeindex = nodeindex + 1
end
end
while node ~= run.after do
local oldnode = node
head, node = removenode(head, node)
freenode(oldnode)
end
return head, node
end
local function shape_run(head, current, run)
if not run.skip then
-- Font loaded with our loader and an HarfBuzz face is present, do our
-- shaping.
local glyphs, offset
head, current, glyphs, offset = shape(head, current, run)
return offset, tonodes(head, current, run, glyphs)
else
return 0, head, run.after
end
end
function process(head, font, _attr, direction)
local newhead, current = head, head
local runs = itemize(head, font, direction)
local offset = 0
for i = 1,#runs do
local run = runs[i]
run.start = run.start - offset
local new_offset
new_offset, newhead, current = shape_run(newhead, current, run)
offset = offset + new_offset
end
return newhead or head
end
local function pageliteral(data)
local n = newnode(whatsit_t, pdfliteral_t)
setfield(n, "mode", 1) -- page
setdata(n, data)
return n
end
local function post_process(head)
for n in traverse(head) do
local props = properties[n]
local startactual, endactual
if props then
startactual = rawget(props, startactual_p)
endactual = rawget(props, endactual_p)
end
if startactual then
local actualtext = "/Span<</ActualText<FEFF"..startactual..">>>BDC"
head = insertbefore(head, n, pageliteral(actualtext))
end
if endactual then
head = insertafter(head, n, pageliteral("EMC"))
end
local replace = getfield(n, "replace")
if replace then
setfield(n, "replace", post_process(replace))
end
local subhead = getfield(n, "head")
if subhead then
setfield(n, "head", post_process(subhead))
end
end
return head
end
local function post_process_nodes(head, groupcode)
return tonode(post_process(todirect(head)))
end
local function run_cleanup()
-- Remove temporary PNG files that we created, if any.
-- FIXME: It would be nice if we wouldn't need this
for _, path in next, pngcachefiles do
osremove(path)
end
end
local function set_tounicode()
for fontid, fontdata in font.each() do
local hbdata = fontdata.hb
if hbdata and fontid == pdf.getfontname(fontid) then
local characters = fontdata.characters
local newcharacters = {}
local hbshared = hbdata.shared
local glyphs = hbshared.glyphs
local nominals = hbshared.nominals
local gid_offset = hbshared.gid_offset
for gid = 0, #glyphs do
local glyph = glyphs[gid]
if glyph.used then
local character = characters[gid + gid_offset]
newcharacters[gid + gid_offset] = character
local unicode = nominals[gid]
if unicode then
newcharacters[unicode] = character
end
character.tounicode = glyph.tounicode or "FFFD"
character.used = true
end
end
font.addcharacters(fontid, { characters = newcharacters })
end
end
end
-- FIXME: Move this into generic parts of luaotfload
local utfchar = utf8.char
local function get_glyph_info(n)
n = todirect(n)
local props = properties[n]
return props and props.glyph_info or utfchar(getchar(n)):gsub('\0', '^^@')
end
fonts.handlers.otf.registerplugin('harf', process)
-- luatexbase does not know how to handle `wrapup_run` callback, teach it.
-- TODO: Move these into ltluatex
luatexbase.callbacktypes.wrapup_run = 1 -- simple
luatexbase.callbacktypes.glyph_info = 1 -- simple
local base_callback_descriptions = luatexbase.callback_descriptions
local base_add_to_callback = luatexbase.add_to_callback
local base_remove_from_callback = luatexbase.remove_from_callback
-- Remove all existing functions from given callback, insert ours, then
-- reinsert the removed ones, so ours takes a priority.
local function add_to_callback(name, func)
local saved_callbacks = {}, ff, dd
for k, v in next, base_callback_descriptions(name) do
saved_callbacks[k] = { base_remove_from_callback(name, v) }
end
base_add_to_callback(name, func, "Harf "..name.." callback")
for _, v in next, saved_callbacks do
base_add_to_callback(name, v[1], v[2])
end
end
add_to_callback('pre_output_filter', post_process_nodes) -- FIXME: Wrong callback, but I want to get rid of the whole function anyway
add_to_callback('wrapup_run', run_cleanup)
add_to_callback('finish_pdffile', set_tounicode)
add_to_callback('glyph_info', get_glyph_info)