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|
if not modules then modules = { } end modules ["extralibs"] = {
version = 2.201,
comment = "companion to luaotfload.lua",
author = "Hans Hagen, Philipp Gesang",
copyright = "PRAGMA ADE / ConTeXt Development Team",
license = "GPL v.2.0",
}
-- extralibs: set up an emulation layer to load additional Context
-- libraries
--===================================================================--
--- PREPARE
--===================================================================--
local getmetatable = getmetatable
local require = require
local select = select
local setmetatable = setmetatable
local tonumber = tonumber
local texattribute = tex.attribute
local new_node = node.new
local copy_node = node.copy
local otffeatures = fonts.constructors.newfeatures "otf"
-----------------------------------------------------------------------
--- namespace
-----------------------------------------------------------------------
--- The “typesetters” namespace isn’t bad at all; there is no need
--- to remove it after loading.
typesetters = typesetters or { }
local typesetters = typesetters
typesetters.kerns = typesetters.kerns or { }
local kerns = typesetters.kerns
kerns.mapping = kerns.mapping or { }
kerns.factors = kerns.factors or { }
local kern_callback = "typesetters.kerncharacters"
typesetters.kernfont = typesetters.kernfont or { }
local kernfont = typesetters.kernfont
-----------------------------------------------------------------------
--- node-ini
-----------------------------------------------------------------------
nodes = nodes or { } --- should be present with luaotfload
local bothways = function (t) return table.swapped (t, t) end
local kerncodes = bothways({
[0] = "fontkern",
[1] = "userkern",
[2] = "accentkern",
})
kerncodes.kerning = kerncodes.fontkern --- idiosyncrasy
nodes.kerncodes = kerncodes
nodes.skipcodes = bothways({
[ 0] = "userskip",
[ 1] = "lineskip",
[ 2] = "baselineskip",
[ 3] = "parskip",
[ 4] = "abovedisplayskip",
[ 5] = "belowdisplayskip",
[ 6] = "abovedisplayshortskip",
[ 7] = "belowdisplayshortskip",
[ 8] = "leftskip",
[ 9] = "rightskip",
[ 10] = "topskip",
[ 11] = "splittopskip",
[ 12] = "tabskip",
[ 13] = "spaceskip",
[ 14] = "xspaceskip",
[ 15] = "parfillskip",
[ 16] = "thinmuskip",
[ 17] = "medmuskip",
[ 18] = "thickmuskip",
[100] = "leaders",
[101] = "cleaders",
[102] = "xleaders",
[103] = "gleaders",
})
-----------------------------------------------------------------------
--- node-res
-----------------------------------------------------------------------
nodes.pool = nodes.pool or { }
local pool = nodes.pool
local kern = new_node("kern", nodes.kerncodes.userkern)
local glue_spec = new_node "glue_spec"
pool.kern = function (k)
local n = copy_node(kern)
n.kern = k
return n
end
pool.gluespec = function (width, stretch, shrink,
stretch_order, shrink_order)
local s = copy_node(glue_spec)
if width then s.width = width end
if stretch then s.stretch = stretch end
if shrink then s.shrink = shrink end
if stretch_order then s.stretch_order = stretch_order end
if shrink_order then s.shrink_order = shrink_order end
return s
end
pool.glue = function (width, stretch, shrink,
stretch_order, shrink_order)
local n = new_node"glue"
if not width then
-- no spec
elseif width == false or tonumber(width) then
local s = copy_node(glue_spec)
if width then s.width = width end
if stretch then s.stretch = stretch end
if shrink then s.shrink = shrink end
if stretch_order then s.stretch_order = stretch_order end
if shrink_order then s.shrink_order = shrink_order end
n.spec = s
else
-- shared
n.spec = copy_node(width)
end
return n
end
-----------------------------------------------------------------------
--- font-hsh
-----------------------------------------------------------------------
--- some initialization resembling font-hsh
local fonthashes = fonts.hashes
local identifiers = fonthashes.identifiers --- was: fontdata
local chardata = fonthashes.characters
local quaddata = fonthashes.quads
local markdata = fonthashes.marks
local parameters = fonthashes.parameters
--- ('a, 'a) hash -> (('a, 'a) hash -> 'a -> 'a) -> ('a, 'a) hash
local setmetatableindex = function (t, f)
local mt = getmetatable(t)
if mt then
mt.__index = f
else
setmetatable(t, { __index = f })
end
return t
end
if not parameters then
parameters = { }
setmetatableindex(parameters, function(t, k)
if k == true then
return parameters[currentfont()]
else
local parameters = identifiers[k].parameters
t[k] = parameters
return parameters
end
end)
fonthashes.parameters = parameters
end
if not chardata then
chardata = { }
setmetatableindex(chardata, function(t, k)
if k == true then
return chardata[currentfont()]
else
local characters = identifiers[k].characters
t[k] = characters
return characters
end
end)
fonthashes.characters = chardata
end
if not quaddata then
quaddata = { }
setmetatableindex(quaddata, function(t, k)
if k == true then
return quads[currentfont()]
else
local parameters = parameters[k]
local quad = parameters and parameters.quad or 0
t[k] = quad
return quad
end
end)
fonthashes.quads = quaddata
end
if not markdata then
markdata = { }
setmetatableindex(markdata, function(t, k)
if k == true then
return marks[currentfont()]
else
local resources = identifiers[k].resources or { }
local marks = resources.marks or { }
t[k] = marks
return marks
end
end)
fonthashes.marks = markdata
end
--- next stems from the multilingual interface
interfaces = interfaces or { }
interfaces.variables = interfaces.variables or { }
interfaces.variables.max = "max"
-----------------------------------------------------------------------
--- attr-ini
-----------------------------------------------------------------------
attributes = attributes or { } --- to be removed with cleanup
local hidden = {
a_kerns = luatexbase.new_attribute("typo-krn:a_kerns", true),
a_fontkern = luatexbase.new_attribute("typo-krn:a_fontkern", true),
}
attributes.private = attributes.private or function (attr_name)
local res = hidden[attr_name]
if not res then
res = luatexbase.new_attribute(attr_name)
end
return res
end
if luatexbase.get_unset_value then
attributes.unsetvalue = luatexbase.get_unset_value()
else -- old luatexbase
attributes.unsetvalue = (luatexbase.luatexversion < 37) and -1
or -2147483647
end
-----------------------------------------------------------------------
--- luat-sto
-----------------------------------------------------------------------
--- Storage is so ridiculously well designed in Context it’s a pity
--- we can’t just force every package author to use it.
storage = storage or { }
storage.register = storage.register or function (...)
local t = { ... }
--- sorry
return t
end
-----------------------------------------------------------------------
--- node-fin
-----------------------------------------------------------------------
local plugin_store = { }
local installattributehandler = function (plugin)
--- Context has some load() magic here.
plugin_store[plugin.name] = plugin.processor
end
nodes.installattributehandler = installattributehandler
-----------------------------------------------------------------------
--- node-tsk
-----------------------------------------------------------------------
nodes.tasks = nodes.tasks or { }
nodes.tasks.enableaction = function () end
-----------------------------------------------------------------------
--- core-ctx
-----------------------------------------------------------------------
commands = commands or { }
--===================================================================--
--- LOAD
--===================================================================--
--- we should be ready at this moment to insert the libraries
require "luaotfload-typo-krn" --- typesetters.kerns
require "luaotfload-letterspace" --- typesetters.kernfont
--===================================================================--
--- CLEAN
--===================================================================--
--- interface
-----------------------------------------------------------------------
local factors = kerns.factors
local mapping = kerns.mapping
local unsetvalue = attributes.unset_value
local process_kerns = plugin_store.kern
--- kern_callback : normal
--- · callback: process_kerns
--- · enabler: enablecharacterkerning
--- · disabler: disablecharacterkerning
--- · interface: kerns.set
--- kernfont_callback : fontwise
--- · callback: kernfont.handler
--- · enabler: enablefontkerning
--- · disabler: disablefontkerning
--- callback wrappers
--- (node_t -> node_t) -> string -> string list -> bool
local registered_as = { } --- procname -> callbacks
local add_processor = function (processor, name, ...)
local callbacks = { ... }
for i=1, #callbacks do
luatexbase.add_to_callback(callbacks[i], processor, name)
end
registered_as[name] = callbacks --- for removal
return true
end
--- string -> bool
local remove_processor = function (name)
local callbacks = registered_as[name]
if callbacks then
for i=1, #callbacks do
luatexbase.remove_from_callback(callbacks[i], name)
end
return true
end
return false --> unregistered
end
--- we use the same callbacks as a node processor in Context
--- unit -> bool
local enablecharacterkerning = function ( )
return add_processor(function (head)
return process_kerns("kerns", hidden.a_kerns, head)
end,
"typesetters.kerncharacters",
"pre_linebreak_filter", "hpack_filter"
)
end
--- unit -> bool
local disablecharacterkerning = function ( )
return remove_processor "typesetters.kerncharacters"
end
kerns.enablecharacterkerning = enablecharacterkerning
kerns.disablecharacterkerning = disablecharacterkerning
--- now for the simplistic variant
--- unit -> bool
local enablefontkerning = function ( )
return add_processor(
kernfont.handler,
"typesetters.kernfont",
"pre_linebreak_filter", "hpack_filter"
)
end
--- unit -> bool
local disablefontkerning = function ( )
return remove_processor "typesetters.kernfont"
end
--- fontwise kerning uses a font property for passing along the
--- letterspacing factor
local fontkerning_enabled = false --- callback state
--- fontobj -> float -> unit
local initializefontkerning = function (tfmdata, factor)
if factor ~= "max" then
factor = tonumber(factor) or 0
end
if factor == "max" or factor ~= 0 then
local fontproperties = tfmdata.properties
if fontproperties then
--- hopefully this field stays unused otherwise
fontproperties.kerncharacters = factor
end
if not fontkerning_enabled then
fontkerning_enabled = enablefontkerning()
end
end
end
--- like the font colorization, fontwise kerning is hooked into the
--- feature mechanism
otffeatures.register {
name = "letterspace", --"kerncharacters",
description = "letterspace", --"kerncharacters",
initializers = {
base = initializefontkerning,
node = initializefontkerning,
}
}
kerns.set = nil
local characterkerning_enabled = false
kerns.set = function (factor)
if factor ~= "max" then
factor = tonumber(factor) or 0
end
if factor == "max" or factor ~= 0 then
if not characterkerning_enabled then
enablecharacterkerning()
characterkerning_enabled = true
end
local a = factors[factor]
if not a then
a = #mapping + 1
factors[factors], mapping[a] = a, factor
end
factor = a
else
factor = unsetvalue
end
texattribute[hidden.a_kerns] = factor
return factor
end
-----------------------------------------------------------------------
--- options
-----------------------------------------------------------------------
kerns .keepligature = false --- supposed to be of type function
kerns .keeptogether = false --- supposed to be of type function
kernfont.keepligature = false --- supposed to be of type function
kernfont.keeptogether = false --- supposed to be of type function
-----------------------------------------------------------------------
--- erase fake Context layer
-----------------------------------------------------------------------
attributes = nil
--commands = nil --- used in lualibs
storage = nil --- not to confuse with utilities.storage
nodes.tasks = nil
collectgarbage"collect"
--[[example--
\input luaotfload.sty
\def\setcharacterkerning#1{% #1 factor : float
\directlua{typesetters.kerns.set(0.618)}%
}
%directlua{typesetters.kerns.enablecharacterkerning()}
\font\iwona = "name:Iwona:mode=node" at 42pt
\font\lmregular = "name:Latin Modern Roman:mode=node" at 42pt
{\iwona
foo
{\setcharacterkerning{0.618}%
bar}
baz}
{\lmregular
foo {\setcharacterkerning{0.125}ff fi ffi fl Th} baz}
{\lmregular
\directlua{ %% I’m not exactly sure how those work
typesetters.kerns.keepligature = function (start)
print("[liga]", start)
return true
end
typesetters.kerns.keeptogether = function (start)
print("[keeptogether]", start)
return true
end}%
foo {\setcharacterkerning{0.125}ff fi ffi fl Th} baz}
\bye
--example]]--
-- vim:ts=2:sw=2:expandtab
|