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-rw-r--r--src/luaotfload-init.lua252
1 files changed, 252 insertions, 0 deletions
diff --git a/src/luaotfload-init.lua b/src/luaotfload-init.lua
index 4968877..22ad704 100644
--- a/src/luaotfload-init.lua
+++ b/src/luaotfload-init.lua
@@ -57,3 +57,255 @@ local load_fontloader_module = luaotfload.loaders.fontloader
load_luaotfload_module "log"
+local log = luaotfload.log
+local logreport = log.report
+
+log.set_loglevel (default_log_level)
+
+--[[doc--
+
+ \subsection{Preparing the Font Loader}
+ We treat the fontloader as a black box so behavior is consistent
+ between formats.
+ We load the fontloader code directly in the same fashion as the
+ Plain format \identifier{luatex-fonts} that is part of Context.
+ How this is executed depends on the presence on the
+ \emphasis{merged font loader code}.
+ In \identifier{luaotfload} this is contained in the file
+ \fileent{luaotfload-merged.lua}.
+ If this file cannot be found, the original libraries from \CONTEXT
+ of which the merged code was composed are loaded instead.
+ Since these files are not shipped with Luaotfload, an installation
+ of Context is required.
+ (Since we pull the fontloader directly from the Context minimals,
+ the necessary Context version is likely to be more recent than that
+ of other TeX distributions like Texlive.)
+ The imported font loader will call \luafunction{callback.register}
+ once while reading \fileent{font-def.lua}.
+ This is unavoidable unless we modify the imported files, but
+ harmless if we make it call a dummy instead.
+ However, this problem might vanish if we decide to do the merging
+ ourselves, like the \identifier{lualibs} package does.
+ With this step we would obtain the freedom to load our own
+ overrides in the process right where they are needed, at the cost
+ of losing encapsulation.
+ The decision on how to progress is currently on indefinite hold.
+
+--doc]]--
+
+local starttime = os.gettimeofday ()
+local trapped_register = callback.register
+callback.register = function (id)
+ logreport ("log", 4, "main",
+ "Dummy callback.register() invoked on %s.",
+ id)
+end
+
+
+--[[doc--
+
+ By default, the fontloader requires a number of \emphasis{private
+ attributes} for internal use.
+ These must be kept consistent with the attribute handling methods
+ as provided by \identifier{luatexbase}.
+ Our strategy is to override the function that allocates new
+ attributes before we initialize the font loader, making it a
+ wrapper around \luafunction{luatexbase.new_attribute}.\footnote{%
+ Many thanks, again, to Hans Hagen for making this part
+ configurable!
+ }
+ The attribute identifiers are prefixed “\fileent{luaotfload@}” to
+ avoid name clashes.
+
+--doc]]--
+
+do
+ local new_attribute = luatexbase.new_attribute
+ local the_attributes = luatexbase.attributes
+
+ attributes = attributes or { }
+
+ attributes.private = function (name)
+ local attr = "luaotfload@" .. name --- used to be: “otfl@”
+ local number = the_attributes[attr]
+ if not number then
+ number = new_attribute(attr)
+ end
+ return number
+ end
+end
+
+--[[doc--
+
+ These next lines replicate the behavior of
+ \fileent{luatex-fonts.lua}.
+
+--doc]]--
+
+local context_environment = { }
+
+local push_namespaces = function ()
+ logreport ("log", 4, "main", "push namespace for font loader")
+ local normalglobal = { }
+ for k, v in next, _G do
+ normalglobal[k] = v
+ end
+ return normalglobal
+end
+
+local pop_namespaces = function (normalglobal, isolate)
+ if normalglobal then
+ local _G = _G
+ local mode = "non-destructive"
+ if isolate then mode = "destructive" end
+ logreport ("log", 4, "main", "pop namespace from font loader -- " .. mode)
+ for k, v in next, _G do
+ if not normalglobal[k] then
+ context_environment[k] = v
+ if isolate then
+ _G[k] = nil
+ end
+ end
+ end
+ for k, v in next, normalglobal do
+ _G[k] = v
+ end
+ -- just to be sure:
+ setmetatable(context_environment,_G)
+ else
+ logreport ("both", 0, "main",
+ "irrecoverable error during pop_namespace: no globals to restore")
+ os.exit()
+ end
+end
+
+luaotfload.context_environment = context_environment
+luaotfload.push_namespaces = push_namespaces
+luaotfload.pop_namespaces = pop_namespaces
+
+local our_environment = push_namespaces()
+
+--[[doc--
+
+ The font loader requires that the attribute with index zero be
+ zero. We happily oblige.
+ (Cf. \fileent{luatex-fonts-nod.lua}.)
+
+--doc]]--
+
+tex.attribute[0] = 0
+
+--[[doc--
+
+ Now that things are sorted out we can finally load the fontloader.
+
+ For less current distibutions we ship the code from TL 2014 that should be
+ compatible with Luatex 0.76.
+
+--doc]]--
+
+load_fontloader_module (luaotfload.fontloader_package)
+
+---load_fontloader_module "font-odv.lua" --- <= Devanagari support from Context
+
+if fonts then
+
+ --- The Initialization is highly idiosyncratic.
+
+ if not fonts._merge_loaded_message_done_ then
+ logreport ("log", 5, "main", [["I am using the merged fontloader here.]])
+ logreport ("log", 5, "main", [[ If you run into problems or experience unexpected]])
+ logreport ("log", 5, "main", [[ behaviour, and if you have ConTeXt installed you can try]])
+ logreport ("log", 5, "main", [[ to delete the file 'fontloader-fontloader.lua' as I might]])
+ logreport ("log", 5, "main", [[ then use the possibly updated libraries. The merged]])
+ logreport ("log", 5, "main", [[ version is not supported as it is a frozen instance.]])
+ logreport ("log", 5, "main", [[ Problems can be reported to the ConTeXt mailing list."]])
+ end
+ fonts._merge_loaded_message_done_ = true
+
+else--- the loading sequence is known to change, so this might have to
+ --- be updated with future updates!
+ --- do not modify it though unless there is a change to the merged
+ --- package!
+ load_fontloader_module "l-lua"
+ load_fontloader_module "l-lpeg"
+ load_fontloader_module "l-function"
+ load_fontloader_module "l-string"
+ load_fontloader_module "l-table"
+ load_fontloader_module "l-io"
+ load_fontloader_module "l-file"
+ load_fontloader_module "l-boolean"
+ load_fontloader_module "l-math"
+ load_fontloader_module "util-str"
+ load_fontloader_module "luatex-basics-gen"
+ load_fontloader_module "data-con"
+ load_fontloader_module "luatex-basics-nod"
+ load_fontloader_module "font-ini"
+ load_fontloader_module "font-con"
+ load_fontloader_module "luatex-fonts-enc"
+ load_fontloader_module "font-cid"
+ load_fontloader_module "font-map"
+ load_fontloader_module "luatex-fonts-syn"
+ load_fontloader_module "luatex-fonts-tfm"
+ load_fontloader_module "font-oti"
+ load_fontloader_module "font-otf"
+ load_fontloader_module "font-otb"
+ load_fontloader_module "luatex-fonts-inj" --> since 2014-01-07, replaces node-inj.lua
+ load_fontloader_module "luatex-fonts-ota"
+ load_fontloader_module "luatex-fonts-otn" --> since 2014-01-07, replaces font-otn.lua
+ load_fontloader_module "font-otp" --> since 2013-04-23
+ load_fontloader_module "luatex-fonts-lua"
+ load_fontloader_module "font-def"
+ load_fontloader_module "luatex-fonts-def"
+ load_fontloader_module "luatex-fonts-ext"
+ load_fontloader_module "luatex-fonts-cbk"
+end --- non-merge fallback scope
+
+--[[doc--
+
+ Here we adjust the globals created during font loader
+ initialization. If the second argument to
+ \luafunction{pop_namespaces()} is \verb|true| this will restore the
+ state of \luafunction{_G}, eliminating every global generated since
+ the last call to \luafunction{push_namespaces()}. At the moment we
+ see no reason to do this, and since the font loader is considered
+ an essential part of \identifier{luatex} as well as a very well
+ organized piece of code, we happily concede it the right to add to
+ \luafunction{_G} if needed.
+
+--doc]]--
+
+pop_namespaces(our_environment, false)-- true)
+
+logreport ("both", 1, "main",
+ "fontloader loaded in %0.3f seconds", os.gettimeofday()-starttime)
+
+--[[doc--
+
+ \subsection{Callbacks}
+ After the fontloader is ready we can restore the callback trap from
+ \identifier{luatexbase}.
+
+--doc]]--
+
+callback.register = trapped_register
+
+--[[doc--
+
+ We do our own callback handling with the means provided by
+ luatexbase.
+ Note: \luafunction{pre_linebreak_filter} and
+ \luafunction{hpack_filter} are coupled in \CONTEXT in the concept
+ of \emphasis{node processor}.
+
+--doc]]--
+
+luatexbase.add_to_callback("pre_linebreak_filter",
+ nodes.simple_font_handler,
+ "luaotfload.node_processor",
+ 1)
+luatexbase.add_to_callback("hpack_filter",
+ nodes.simple_font_handler,
+ "luaotfload.node_processor",
+ 1)
+