if not modules then modules = { } end modules ['font-ota'] = {
version = 1.001,
comment = "companion to font-ini.mkiv",
author = "Hans Hagen, PRAGMA-ADE, Hasselt NL",
copyright = "PRAGMA ADE / ConTeXt Development Team",
license = "see context related readme files"
}
-- context only
local type = type
local setmetatableindex = table.setmetatableindex
if not trackers then trackers = { register = function() end } end
----- trace_analyzing = false trackers.register("otf.analyzing", function(v) trace_analyzing = v end)
local fonts, nodes, node = fonts, nodes, node
local allocate = utilities.storage.allocate
local otf = fonts.handlers.otf
local analyzers = fonts.analyzers
local initializers = allocate()
local methods = allocate()
analyzers.initializers = initializers
analyzers.methods = methods
local nuts = nodes.nuts
local tonut = nuts.tonut
local getnext = nuts.getnext
local getprev = nuts.getprev
local getprev = nuts.getprev
local getprop = nuts.getprop
local setprop = nuts.setprop
local getsubtype = nuts.getsubtype
local getchar = nuts.getchar
local ischar = nuts.ischar
local endofmath = nuts.endofmath
local nodecodes = nodes.nodecodes
----- glyph_code = nodecodes.glyph
local disc_code = nodecodes.disc
local math_code = nodecodes.math
local fontdata = fonts.hashes.identifiers
local categories = characters and characters.categories or { } -- sorry, only in context
local chardata = characters and characters.data
local otffeatures = fonts.constructors.features.otf
local registerotffeature = otffeatures.register
-- Analyzers run per script and/or language and are needed in order to process
-- features right.
local setstate = nuts.setstate
local getstate = nuts.getstate
if not setstate or not getstate then
-- generic (might move to the nod lib)
setstate = function(n,v)
setprop(n,"state",v)
end
getstate = function(n,v)
local s = getprop(n,"state")
if v then
return s == v
else
return s
end
end
nuts.setstate = setstate
nuts.getstate = getstate
end
-- never use these numbers directly
local s_init = 1 local s_rphf = 7
local s_medi = 2 local s_half = 8
local s_fina = 3 local s_pref = 9
local s_isol = 4 local s_blwf = 10
local s_mark = 5 local s_pstf = 11
local s_rest = 6
local states = allocate {
init = s_init,
medi = s_medi,
med2 = s_medi,
fina = s_fina,
fin2 = s_fina,
fin3 = s_fina,
isol = s_isol,
mark = s_mark,
rest = s_rest,
rphf = s_rphf,
half = s_half,
pref = s_pref,
blwf = s_blwf,
pstf = s_pstf,
}
local features = allocate {
init = s_init,
medi = s_medi,
med2 = s_medi,
fina = s_fina,
fin2 = s_fina,
fin3 = s_fina,
isol = s_isol,
-- mark = s_mark,
-- rest = s_rest,
rphf = s_rphf,
half = s_half,
pref = s_pref,
blwf = s_blwf,
pstf = s_pstf,
}
analyzers.states = states
analyzers.features = features
analyzers.useunicodemarks = false
-- todo: analyzers per script/lang, cross font, so we need an font id hash -> script
-- e.g. latin -> hyphenate, arab -> 1/2/3 analyze -- its own namespace
-- done can go away as can tonut
function analyzers.setstate(head,font)
local useunicodemarks = analyzers.useunicodemarks
local tfmdata = fontdata[font]
local descriptions = tfmdata.descriptions
local first, last, current, n, done = nil, nil, head, 0, false -- maybe make n boolean
current = tonut(current)
while current do
local char, id = ischar(current,font)
if char and not getstate(current) then
done = true
local d = descriptions[char]
if d then
if d.class == "mark" then
done = true
setstate(current,s_mark)
elseif useunicodemarks and categories[char] == "mn" then
done = true
setstate(current,s_mark)
elseif n == 0 then
first, last, n = current, current, 1
setstate(current,s_init)
else
last, n = current, n+1
setstate(current,s_medi)
end
else -- finish
if first and first == last then
setstate(last,s_isol)
elseif last then
setstate(last,s_fina)
end
first, last, n = nil, nil, 0
end
elseif char == false then
-- other font
if first and first == last then
setstate(last,s_isol)
elseif last then
setstate(last,s_fina)
end
first, last, n = nil, nil, 0
if id == math_code then
current = endofmath(current)
end
elseif id == disc_code then
-- always in the middle .. it doesn't make much sense to assign a property
-- here ... we might at some point decide to flag the components when present
-- but even then it's kind of bogus
setstate(current,s_medi)
last = current
else -- finish
if first and first == last then
setstate(last,s_isol)
elseif last then
setstate(last,s_fina)
end
first, last, n = nil, nil, 0
if id == math_code then
current = endofmath(current)
end
end
current = getnext(current)
end
if first and first == last then
setstate(last,s_isol)
elseif last then
setstate(last,s_fina)
end
return head, done
end
-- in the future we will use language/script attributes instead of the
-- font related value, but then we also need dynamic features which is
-- somewhat slower; and .. we need a chain of them
local function analyzeinitializer(tfmdata,value) -- attr
local script, language = otf.scriptandlanguage(tfmdata) -- attr
local action = initializers[script]
if not action then
-- skip
elseif type(action) == "function" then
return action(tfmdata,value)
else
local action = action[language]
if action then
return action(tfmdata,value)
end
end
end
local function analyzeprocessor(head,font,attr)
local tfmdata = fontdata[font]
local script, language = otf.scriptandlanguage(tfmdata,attr)
local action = methods[script]
if not action then
-- skip
elseif type(action) == "function" then
return action(head,font,attr)
else
action = action[language]
if action then
return action(head,font,attr)
end
end
return head, false
end
registerotffeature {
name = "analyze",
description = "analysis of character classes",
default = true,
initializers = {
node = analyzeinitializer,
},
processors = {
position = 1,
node = analyzeprocessor,
}
}
-- latin
methods.latn = analyzers.setstate
-------.dflt = analyzers.setstate % can be an option or just the default
local arab_warned = { }
local function warning(current,what)
local char = getchar(current)
if not arab_warned[char] then
log.report("analyze","arab: character %C has no %a class",char,what)
arab_warned[char] = true
end
end
local mappers = allocate {
l = s_init, -- left
d = s_medi, -- double
c = s_medi, -- joiner
r = s_fina, -- right
u = s_isol, -- nonjoiner
}
-- we can also use this trick for devanagari
local classifiers = characters.classifiers
if not classifiers then
local f_arabic, l_arabic = characters.blockrange("arabic")
local f_syriac, l_syriac = characters.blockrange("syriac")
local f_mandiac, l_mandiac = characters.blockrange("mandiac")
local f_nko, l_nko = characters.blockrange("nko")
local f_ext_a, l_ext_a = characters.blockrange("arabicextendeda")
classifiers = setmetatableindex(function(t,k)
if type(k) == "number" then
local c = chardata[k]
local v = false
if c then
local arabic = c.arabic
if arabic then
v = mappers[arabic]
if not v then
log.report("analyze","error in mapping arabic %C",k)
-- error
v = false
end
elseif (k >= f_arabic and k <= l_arabic) or
(k >= f_syriac and k <= l_syriac) or
(k >= f_mandiac and k <= l_mandiac) or
(k >= f_nko and k <= l_nko) or
(k >= f_ext_a and k <= l_ext_a) then
if categories[k] == "mn" then
v = s_mark
else
v = s_rest
end
end
end
t[k] = v
return v
end
end)
characters.classifiers = classifiers
end
function methods.arab(head,font,attr)
local first, last, c_first, c_last
local current = head
local done = false
current = tonut(current)
while current do
local char, id = ischar(current,font)
if char and not getstate(current) then
done = true
local classifier = classifiers[char]
if not classifier then
if last then
if c_last == s_medi or c_last == s_fina then
setstate(last,s_fina)
else
warning(last,"fina")
setstate(last,s_error)
end
first, last = nil, nil
elseif first then
if c_first == s_medi or c_first == s_fina then
setstate(first,s_isol)
else
warning(first,"isol")
setstate(first,s_error)
end
first = nil
end
elseif classifier == s_mark then
setstate(current,s_mark)
elseif classifier == s_isol then
if last then
if c_last == s_medi or c_last == s_fina then
setstate(last,s_fina)
else
warning(last,"fina")
setstate(last,s_error)
end
first, last = nil, nil
elseif first then
if c_first == s_medi or c_first == s_fina then
setstate(first,s_isol)
else
warning(first,"isol")
setstate(first,s_error)
end
first = nil
end
setstate(current,s_isol)
elseif classifier == s_medi then
if first then
last = current
c_last = classifier
setstate(current,s_medi)
else
setstate(current,s_init)
first = current
c_first = classifier
end
elseif classifier == s_fina then
if last then
if getstate(last) ~= s_init then
setstate(last,s_medi)
end
setstate(current,s_fina)
first, last = nil, nil
elseif first then
-- if getstate(first) ~= s_init then
-- -- needs checking
-- setstate(first,s_medi)
-- end
setstate(current,s_fina)
first = nil
else
setstate(current,s_isol)
end
else -- classifier == s_rest
setstate(current,s_rest)
if last then
if c_last == s_medi or c_last == s_fina then
setstate(last,s_fina)
else
warning(last,"fina")
setstate(last,s_error)
end
first, last = nil, nil
elseif first then
if c_first == s_medi or c_first == s_fina then
setstate(first,s_isol)
else
warning(first,"isol")
setstate(first,s_error)
end
first = nil
end
end
else
if last then
if c_last == s_medi or c_last == s_fina then
setstate(last,s_fina)
else
warning(last,"fina")
setstate(last,s_error)
end
first, last = nil, nil
elseif first then
if c_first == s_medi or c_first == s_fina then
setstate(first,s_isol)
else
warning(first,"isol")
setstate(first,s_error)
end
first = nil
end
if id == math_code then -- a bit duplicate as we test for glyphs twice
current = endofmath(current)
end
end
current = getnext(current)
end
if last then
if c_last == s_medi or c_last == s_fina then
setstate(last,s_fina)
else
warning(last,"fina")
setstate(last,s_error)
end
elseif first then
if c_first == s_medi or c_first == s_fina then
setstate(first,s_isol)
else
warning(first,"isol")
setstate(first,s_error)
end
end
return head, done
end
methods.syrc = methods.arab
methods.mand = methods.arab
methods.nko = methods.arab
-- a quick first attemp .. more later
do
-- https://github.com/n8willis/opentype-shaping-documents/blob/master/opentype-shaping-mongolian.md#joining-properties
-- todo syrc
local joining = setmetatableindex(function(t,k)
if type(k) == "number" then
local c = chardata[k]
local v = false
if c then
local mongolian = c.mongolian
--
v = mongolian
end
t[k] = v
return v
end
end)
function methods.mong(head,font,attr)
local first, last
local current = head
local done = false
local prevjoin = nil
local prestate = nil
current = tonut(current)
local function wrapup()
if last then
if last ~= first then
local s = getstate(last)
if s == s_medi then
setstate(last,s_fina)
elseif s == s_init then
setstate(last,s_isol)
end
end
last = nil
first = nil
prevjoin = nil
prestate = nil
end
end
while current do
local char, id = ischar(current,font)
if char and not getstate(current) then
local currjoin = joining[char]
done = true
if not last then
setstate(current,s_isol)
prevjoin = currjoin
first = current
last = current
prevstate = s_isol
elseif currjoin == "t" then -- transparent
-- keep state
last = current
elseif prevjoin == "d" or prevjoin == "jc" or prevjoin == "l" then
if currjoin == "d" or prevjoin == "jc" or prevjoin == "r" then
local s = getstate(last)
if s == s_isol then
setstate(last,s_init)
elseif s == s_fina then
setstate(last,s_medi)
end
setstate(current,s_fina)
prevstate = s_fina
elseif prevjoin == "nj" or prevjoin == "l" then
local s = getstate(last)
if s == s_medi then
setstate(last,s_fina)
elseif s == s_init then
setstate(last,s_isol)
end
setstate(current,s_isol)
prevstate = s_isol
end
prevjoin = currjoin
last = current
elseif prevjoin == "nj" or prevjoin == "r" then
if s == s_medi then
setstate(last,s_fina)
elseif s == s_init then
setstate(last,s_isol)
end
setstate(current,s_isol)
prevjoin = currjoin
prevstate = s_isol
last = current
elseif last then
wrapup()
end
else
if last then
wrapup()
end
if id == math_code then -- a bit duplicate as we test for glyphs twice
current = endofmath(current)
end
end
current = getnext(current)
end
if last then
wrapup()
end
return head, done
end
end
directives.register("otf.analyze.useunicodemarks",function(v)
analyzers.useunicodemarks = v
end)