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|
if not modules then modules = { } end modules ['font-otc'] = {
version = 1.001,
comment = "companion to font-otf.lua (context)",
author = "Hans Hagen, PRAGMA-ADE, Hasselt NL",
copyright = "PRAGMA ADE / ConTeXt Development Team",
license = "see context related readme files"
}
local format, insert, sortedkeys = string.format, table.insert, table.sortedkeys
local type, next = type, next
local lpegmatch = lpeg.match
local utfbyte = utf.byte
-- we assume that the other otf stuff is loaded already
local trace_loading = false trackers.register("otf.loading", function(v) trace_loading = v end)
local report_otf = logs.reporter("fonts","otf loading")
local fonts = fonts
local otf = fonts.handlers.otf
local registerotffeature = otf.features.register
local setmetatableindex = table.setmetatableindex
local normalized = {
substitution = "substitution",
single = "substitution",
ligature = "ligature",
alternate = "alternate",
multiple = "multiple",
kern = "kern",
}
local types = {
substitution = "gsub_single",
ligature = "gsub_ligature",
alternate = "gsub_alternate",
multiple = "gsub_multiple",
kern = "gpos_pair",
}
setmetatableindex(types, function(t,k) t[k] = k return k end) -- "key"
local everywhere = { ["*"] = { ["*"] = true } } -- or: { ["*"] = { "*" } }
local noflags = { }
-- beware: shared, maybe we should copy the sequence
local function addfeature(data,feature,specifications)
local descriptions = data.descriptions
local resources = data.resources
local features = resources.features
local sequences = resources.sequences
if not features or not sequences then
return
end
local gsubfeatures = features.gsub
if gsubfeatures and gsubfeatures[feature] then
return -- already present
end
local fontfeatures = resources.features or everywhere
local unicodes = resources.unicodes
local splitter = lpeg.splitter(" ",unicodes)
local done = 0
local skip = 0
if not specifications[1] then
-- so we accept a one entry specification
specifications = { specifications }
end
local function tounicode(code)
if not code then
return
elseif type(code) == "number" then
return code
else
return unicodes[code] or utfbyte(code)
end
end
local coverup = otf.coverup
local coveractions = coverup.actions
local stepkey = coverup.stepkey
local register = coverup.register
for s=1,#specifications do
local specification = specifications[s]
local valid = specification.valid
if not valid or valid(data,specification,feature) then
local initialize = specification.initialize
if initialize then
-- when false is returned we initialize only once
specification.initialize = initialize(specification,data) and initialize or nil
end
local askedfeatures = specification.features or everywhere
local askedsteps = specifications.steps or specification.subtables or { specification.data } or { }
local featuretype = normalized[specification.type or "substitution"] or "substitution"
local featureflags = specification.flags or noflags
local featureorder = specification.order or { feature }
local added = false
local nofsteps = 0
local steps = { }
for i=1,#askedsteps do
local list = askedsteps[i]
local coverage = { }
local cover = coveractions[featuretype]
local format = nil
if not cover then
-- unknown
elseif featuretype == "substitution" then
for code, replacement in next, list do
local unicode = tounicode(code)
local description = descriptions[unicode]
if description then
if type(replacement) == "table" then
replacement = replacement[1]
end
replacement = tounicode(replacement)
if replacement and descriptions[replacement] then
cover(coverage,unicode,replacement)
done = done + 1
else
skip = skip + 1
end
else
skip = skip + 1
end
end
elseif featuretype == "ligature" then
for code, ligature in next, list do
local unicode = tounicode(code)
local description = descriptions[unicode]
if description then
if type(ligature) == "string" then
ligature = { lpegmatch(splitter,ligature) }
end
local present = true
for i=1,#ligature do
local l = ligature[i]
local u = tounicode(l)
if descriptions[u] then
ligature[i] = u
else
present = false
break
end
end
if present then
cover(coverage,unicode,ligature)
done = done + 1
else
skip = skip + 1
end
else
skip = skip + 1
end
end
elseif featuretype == "alternate" then
for code, replacement in next, list do
local unicode = tounicode(code)
local description = descriptions[unicode]
if not description then
skip = skip + 1
elseif type(replacement) == "table" then
local r = { }
for i=1,#replacement do
local u = tounicode(replacement[i])
r[i] = descriptions[u] and u or unicode
end
cover(coverage,unicode,r)
done = done + 1
else
local u = tounicode(replacement)
if u then
cover(coverage,unicode,{ u })
done = done + 1
else
skip = skip + 1
end
end
end
elseif featuretype == "multiple" then -- todo: unicode can be table
for code, replacement in next, list do
local unicode = tounicode(code)
local description = descriptions[unicode]
if not description then
skip = skip + 1
elseif type(replacement) == "table" then
local r, n = { }, 0
for i=1,#replacement do
local u = tounicode(replacement[i])
if descriptions[u] then
n = n + 1
r[n] = u
end
end
if n > 0 then
cover(coverage,unicode,r)
done = done + 1
else
skip = skip + 1
end
else
local u = tounicode(replacement)
if u then
cover(coverage,unicode,{ u })
done = done + 1
else
skip = skip + 1
end
end
end
elseif featuretype == "kern" then
for code, replacement in next, list do
local unicode = tounicode(code)
local description = descriptions[unicode]
if description and type(replacement) == "table" then
local r = { }
for k, v in next, replacement do
local u = tounicode(k)
if u then
r[u] = v
end
end
if next(r) then
cover(coverage,unicode,r)
done = done + 1
else
skip = skip + 1
end
else
skip = skip + 1
end
end
format = "kern"
end
if next(coverage) then
added = true
nofsteps = nofsteps + 1
steps[nofsteps] = register(coverage,featuretype,format,feature,nofsteps,descriptions,resources)
end
end
if added then
-- script = { lang1, lang2, lang3 } or script = { lang1 = true, ... }
for k, v in next, askedfeatures do
if v[1] then
askedfeatures[k] = table.tohash(v)
end
end
local sequence = {
chain = 0,
features = { [feature] = askedfeatures },
flags = featureflags,
name = feature, -- not needed
order = featureorder,
[stepkey] = steps,
nofsteps = nofsteps,
type = types[featuretype],
}
if specification.prepend then
insert(sequences,1,sequence)
else
insert(sequences,sequence)
end
-- register in metadata (merge as there can be a few)
if not gsubfeatures then
gsubfeatures = { }
fontfeatures.gsub = gsubfeatures
end
local k = gsubfeatures[feature]
if not k then
k = { }
gsubfeatures[feature] = k
end
for script, languages in next, askedfeatures do
local kk = k[script]
if not kk then
kk = { }
k[script] = kk
end
for language, value in next, languages do
kk[language] = value
end
end
end
end
end
if trace_loading then
report_otf("registering feature %a, affected glyphs %a, skipped glyphs %a",feature,done,skip)
end
end
otf.enhancers.addfeature = addfeature
local extrafeatures = { }
function otf.addfeature(name,specification)
if type(name) == "table" then
specification = name
name = specification.name
end
if type(name) == "string" then
extrafeatures[name] = specification
end
end
local function enhance(data,filename,raw)
for feature, specification in next, extrafeatures do
addfeature(data,feature,specification)
end
end
otf.enhancers.register("check extra features",enhance)
-- tlig --
local tlig = { -- we need numbers for some fonts so ...
-- endash = "hyphen hyphen",
-- emdash = "hyphen hyphen hyphen",
[0x2013] = { 0x002D, 0x002D },
[0x2014] = { 0x002D, 0x002D, 0x002D },
-- quotedblleft = "quoteleft quoteleft",
-- quotedblright = "quoteright quoteright",
-- quotedblleft = "grave grave",
-- quotedblright = "quotesingle quotesingle",
-- quotedblbase = "comma comma",
}
local tlig_specification = {
type = "ligature",
features = everywhere,
data = tlig,
order = { "tlig" },
flags = noflags,
prepend = true,
}
otf.addfeature("tlig",tlig_specification)
registerotffeature {
name = 'tlig',
description = 'tex ligatures',
}
-- trep
local trep = {
-- [0x0022] = 0x201D,
[0x0027] = 0x2019,
-- [0x0060] = 0x2018,
}
local trep_specification = {
type = "substitution",
features = everywhere,
data = trep,
order = { "trep" },
flags = noflags,
prepend = true,
}
otf.addfeature("trep",trep_specification)
registerotffeature {
name = 'trep',
description = 'tex replacements',
}
-- tcom
if characters.combined then
local tcom = { }
local function initialize()
characters.initialize()
for first, seconds in next, characters.combined do
for second, combination in next, seconds do
tcom[combination] = { first, second }
end
end
-- return false
end
local tcom_specification = {
type = "ligature",
features = everywhere,
data = tcom,
order = { "tcom" },
flags = noflags,
initialize = initialize,
}
otf.addfeature("tcom",tcom_specification)
registerotffeature {
name = 'tcom',
description = 'tex combinations',
}
end
-- anum
local anum_arabic = {
[0x0030] = 0x0660,
[0x0031] = 0x0661,
[0x0032] = 0x0662,
[0x0033] = 0x0663,
[0x0034] = 0x0664,
[0x0035] = 0x0665,
[0x0036] = 0x0666,
[0x0037] = 0x0667,
[0x0038] = 0x0668,
[0x0039] = 0x0669,
}
local anum_persian = {
[0x0030] = 0x06F0,
[0x0031] = 0x06F1,
[0x0032] = 0x06F2,
[0x0033] = 0x06F3,
[0x0034] = 0x06F4,
[0x0035] = 0x06F5,
[0x0036] = 0x06F6,
[0x0037] = 0x06F7,
[0x0038] = 0x06F8,
[0x0039] = 0x06F9,
}
local function valid(data)
local features = data.resources.features
if features then
for k, v in next, features do
for k, v in next, v do
if v.arab then
return true
end
end
end
end
end
local anum_specification = {
{
type = "substitution",
features = { arab = { urd = true, dflt = true } },
order = { "anum" },
data = anum_arabic,
flags = noflags, -- { },
valid = valid,
},
{
type = "substitution",
features = { arab = { urd = true } },
order = { "anum" },
data = anum_persian,
flags = noflags, -- { },
valid = valid,
},
}
otf.addfeature("anum",anum_specification) -- todo: only when there is already an arab script feature
registerotffeature {
name = 'anum',
description = 'arabic digits',
}
-- maybe:
-- fonts.handlers.otf.addfeature("hangulfix",{
-- type = "substitution",
-- features = { ["hang"] = { ["*"] = true } },
-- data = {
-- [0x1160] = 0x119E,
-- },
-- order = { "hangulfix" },
-- flags = { },
-- prepend = true,
-- })
-- fonts.handlers.otf.features.register {
-- name = 'hangulfix',
-- description = 'fixes for hangul',
-- }
-- fonts.handlers.otf.addfeature {
-- name = "stest",
-- type = "substitution",
-- data = {
-- a = "X",
-- b = "P",
-- }
-- }
-- fonts.handlers.otf.addfeature {
-- name = "atest",
-- type = "alternate",
-- data = {
-- a = { "X", "Y" },
-- b = { "P", "Q" },
-- }
-- }
-- fonts.handlers.otf.addfeature {
-- name = "mtest",
-- type = "multiple",
-- data = {
-- a = { "X", "Y" },
-- b = { "P", "Q" },
-- }
-- }
-- fonts.handlers.otf.addfeature {
-- name = "ltest",
-- type = "ligature",
-- data = {
-- X = { "a", "b" },
-- Y = { "d", "a" },
-- }
-- }
-- fonts.handlers.otf.addfeature {
-- name = "ktest",
-- type = "kern",
-- data = {
-- a = { b = -500 },
-- }
-- }
|