merge deferred functionality back into luaotfload.lua

1 files changed, 216 insertions, 12 deletions

diff --git a/luaotfload.lua b/luaotfload.lua
index dd650fd..7266e47 100644
--- a/luaotfload.lua
+++ b/luaotfload.lua
@@ -29,6 +29,11 @@ luaotfload.module = {
     license       = "CC0"
 }
 
+local luatexbase = luatexbase
+
+local type, next = type, next
+local stringfind = string.find
+
 --[[doc--
 No final decision has been made on how to handle font definition.
 At the moment, there are three candidates: The \textsf{generic}
@@ -63,16 +68,6 @@ local loadmodule = function (name)
         error("file %s not found.", tofind)
     end
 end
-luaotfload.loadmodule = loadmodule --- required in deferred code
-
---[[doc--
-The imported font loader will call \verb|callback.register| once
-(during \verb|font-def.lua|).
-This is unavoidable but harmless, so we make it call a dummy instead.
---doc]]--
-local trapped_register = callback.register
-local dummy_function   = function () end
-callback.register      = dummy_function
 
 --[[-- keep --]]
 --- from Hans (all merged):
@@ -155,6 +150,9 @@ In combination with the option \verb|no_callbacks_yet| in
 if not _G.    generic_context then _G.    generic_context = { } end
 if not _G.non_generic_context then _G.non_generic_context = { } end
 
+local     generic_context =    generic_context
+local non_generic_context =non_generic_context
+
 generic_context.no_callbacks_yet = true
 
 _G.non_generic_context = { luatex_fonts = {
@@ -163,7 +161,19 @@ _G.non_generic_context = { luatex_fonts = {
     skip_loading    = true,
 }}
 
-loadmodule("fonts.lua")
+--[[doc--
+The imported font loader will call \verb|callback.register| once
+(during \verb|font-def.lua|).
+This is unavoidable but harmless, so we make it call a dummy instead.
+--doc]]--
+local trapped_register = callback.register
+local dummy_function   = function () end
+callback.register      = dummy_function
+
+--[[doc--
+Now that things are sorted out we can load the fontloader.
+--doc]]--
+loadmodule"fonts.lua"
 
 --[[doc--
 After the fontloader is ready we can restore the callback trap from
@@ -172,7 +182,201 @@ After the fontloader is ready we can restore the callback trap from
 
 callback.register = trapped_register
 
---- then continue in luaotfload-deferred.lua
+local add_to_callback, create_callback =
+      luatexbase.add_to_callback, luatexbase.create_callback
+local reset_callback, call_callback =
+      luatexbase.reset_callback, luatexbase.call_callback
+
+--[[doc--
+We do our own callback handling with the means provided by luatexbase.
+
+Note: \verb|pre_linebreak_filter| and \verb|hpack_filter| are coupled
+in \CONTEXT\ in the concept of \emph{node processor}.
+--doc]]--
+
+add_to_callback("pre_linebreak_filter",
+                generic_context.callback_pre_linebreak_filter,
+                "luaotfload.node_processor",
+                1)
+add_to_callback("hpack_filter",
+                generic_context.callback_hpack_filter,
+                "luaotfload.node_processor",
+                1)
+
+loadmodule"font-otc.lua"
+
+loadmodule"lib-dir.lua"    -- required by font-nms; will change with lualibs update
+loadmodule"font-nms.lua"
+loadmodule"font-clr.lua"
+--loadmodule"font-ovr.lua"
+loadmodule"font-ltx.lua"
+
+local dummy_function = function ( ) end --- upvalue more efficient than lambda
+create_callback("luaotfload.patch_font", "simple", dummy_function)
+
+--[[doc--
+This is a wrapper for the imported font loader.
+As of 2013, everything it does appears to be redundand, so we won’t use
+it.
+Nevertheless, it has been adapted to work with the current structure of
+font data objects and will stay here for reference / until somebody
+reports breakage.
+
+TODO
+This one also enables patching fonts.
+The current fontloader apparently comes with a dedicated mechanism for
+that already: enhancers.
+How those work remains to be figured out.
+--doc]]--
+local define_font_wrapper = function (...)
+    --- we use “tfmdata” (not “fontdata”) for consistency with the
+    --- font loader
+    local tfmdata = fonts.definers.read(...)
+    if type(tfmdata) == "table" and tfmdata.shared then
+        local metadata = tfmdata.shared.rawdata.metadata
+        local mathdata = metadata.math --- do all fonts have this field?
+        if mathdata then
+            local mathconstants = { } --- why new hash, not modify in place?
+            local units_per_em  = metadata.units_per_em
+            local size          = tfmdata.size
+            for k,v in next, mathdata do
+                --- afaics this is alread taken care of by
+                --- definers.read
+                if stringfind(k, "Percent") then
+                    -- keep percent values as is
+                    print(k,v)
+                    mathconstants[k] = v
+                else
+                    mathconstants[k] = v / units_per_em * size
+                end
+            end
+            --- for \overwithdelims
+            --- done by definers.read as well
+            mathconstants.FractionDelimiterSize             = 1.01 * size
+            --- fontloader has 2.4 × size
+            mathconstants.FractionDelimiterDisplayStyleSize = 2.39 * size
+            tfmdata.MathConstants = mathconstants
+        end
+        call_callback("luaotfload.patch_font", tfmdata)
+    end
+    return tfmdata
+end
+
+--[[doc--
+We provide a simplified version of the original font definition
+callback.
+--doc]]--
+local patch_defined_font = function (...)
+    local tfmdata = fonts.definers.read(...)
+    if type(tfmdata) == "table" and tfmdata.shared then
+        call_callback("luaotfload.patch_font", tfmdata)
+    end
+    --inspect(tfmdata.shared.features)
+    return tfmdata
+end
+
+fonts.mode = "node"
+
+function attributes.private(name)
+    local attr   = "otfl@" .. name
+    local number = luatexbase.attributes[attr]
+    if not number then
+        number = luatexbase.new_attribute(attr)
+    end
+    return number
+end
+
+reset_callback("define_font")
+
+if luaotfload.font_definer == "old"  then
+  add_to_callback("define_font",
+                  old_define_font_wrapper,
+                  "luaotfload.define_font",
+                  1)
+elseif luaotfload.font_definer == "generic"  then
+  add_to_callback("define_font",
+                  generic_context.callback_define_font,
+                  "luaotfload.define_font",
+                  1)
+elseif luaotfload.font_definer == "patch"  then
+  add_to_callback("define_font",
+                  patch_defined_font,
+                  "luaotfload.define_font",
+                  1)
+end
+
+--[[doc--
+These vanished in 2011.
+\url{http://repo.or.cz/w/context.git/commitdiff/1455dd60b68c9140db1b9977c9e5ce372b772ec8}
+
+The “ss” stuff is in tables.features in context (see font-ott.lua), but
+commented.
+I’ll get back at restoring it as soon as someone can tell me what those do.
+/phg
+
+local register_base_sub = fonts.otf.features.register_base_substitution
+local gsubs = {
+    "ss01", "ss02", "ss03", "ss04", "ss05",
+    "ss06", "ss07", "ss08", "ss09", "ss10",
+    "ss11", "ss12", "ss13", "ss14", "ss15",
+    "ss16", "ss17", "ss18", "ss19", "ss20",
+}
+
+for _,v in next, gsubs do
+    register_base_sub(v)
+end
+--doc]]--
+
+---TODO check for conflicts with lualibs
+-- imported from "util-sto.lua"
+--table.setmetatablenewindex = function (t,f)
+--    if type(t) ~= "table" then
+--        f, t = t, { }
+--    end
+--    local m = getmetatable(t)
+--    if m then
+--        if f == "ignore" then
+--            m.__newindex = f_ignore
+--        else
+--            m.__newindex = f
+--        end
+--    else
+--        if f == "ignore" then
+--            setmetatable(t, t_ignore)
+--        else
+--            setmetatable(t,{ __newindex = f })
+--        end
+--    end
+--    return t
+--end
+---- this overloads fonts.handlers.features.normalize()
+---- breakage ahead.
+--loadmodule"font-ott.lua"
+
+--add_to_callback("find_vf_file",
+--                 fonts.vf.find,
+--                "luaotfload.find_vf_file")
+
+local set_sscale_diments = function (tfmdata)
+    local mathconstants = tfmdata.MathConstants
+    if mathconstants then
+        local tfmparameters = tfmdata.parameters
+        if mathconstants.ScriptPercentScaleDown then
+            tfmparameters[10] = mathconstants.ScriptPercentScaleDown
+        else -- resort to plain TeX default
+            tfmparameters[10] = 70
+        end
+        if mathconstants.ScriptScriptPercentScaleDown then
+            tfmparameters[11] = mathconstants.ScriptScriptPercentScaleDown
+        else -- resort to plain TeX default
+            tfmparameters[11] = 50
+        end
+    end
+end
+
+add_to_callback("luaotfload.patch_font",
+                set_sscale_diments,
+                "unicodemath.set_sscale_diments")
 
 -- vim:tw=71:sw=2:ts=2:expandtab