Merge pull request #159 from phi-gamma/master

make fontwise letterspacing an official supported feature

1 files changed, 0 insertions, 536 deletions

diff --git a/luaotfload-extralibs.lua b/luaotfload-extralibs.lua
deleted file mode 100644
index 21f738c..0000000
--- a/luaotfload-extralibs.lua
+++ /dev/null
@@ -1,536 +0,0 @@
-if not modules then modules = { } end modules ["extralibs"] = {
-    version   = "2.4",
-    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 tfmdata = identifiers[k]
-      if not tfmdata then --- unsafe
-        tfmdata = font.fonts[k]
-      end
-      if tfmdata then
-        local characters = tfmdata.characters
-        t[k] = characters
-        return characters
-      end
-    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 = { }
-
-      if identifiers[k] then
-        resources = identifiers[k].resources or { }
-      end
-
-      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        = "kernfactor",
-  description = "kernfactor",
-  initializers = {
-    base = initializefontkerning,
-    node = initializefontkerning,
-  }
-}
-
---[[doc--
-
-  The “letterspace” feature is essentially identical with the above
-  “kernfactor” method, but scales the factor to percentages to match
-  Xetex’s behavior. (See the Xetex reference, page 5, section 1.2.2.)
-
-  Since Xetex doesn’t appear to have a (documented) “max” keyword, we
-  assume all input values are numeric.
-
---doc]]--
-
-local initializecompatfontkerning = function (tfmdata, percentage)
-  local factor = tonumber (percentage)
-  if not factor then
-    logs.names_report ("both", 0, "letterspace",
-                       "Invalid argument to letterspace: %s (type %q), was expecting percentage as Lua number instead.",
-                       percentage, type (percentage))
-    return
-  end
-  return initializefontkerning (tfmdata, factor * 0.01)
-end
-
-otffeatures.register {
-  name        = "letterspace",
-  description = "letterspace",
-  initializers = {
-    base = initializecompatfontkerning,
-    node = initializecompatfontkerning,
-  }
-}
-
-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