| Current File : //usr/share/texlive/texmf-dist/tex/luatex/luaotfload/luaotfload-resolvers.lua |
-----------------------------------------------------------------------
-- FILE: luaotfload-resolvers.lua
-- USAGE: ./luaotfload-resolvers.lua
-- DESCRIPTION: Resolvers for hooking into the fontloader
-- REQUIREMENTS: Luaotfload and a decent bit of courage
-- AUTHOR: Philipp Gesang (Phg), <phg@phi-gamma.net>
-----------------------------------------------------------------------
--
--- The bare fontloader uses a set of simplistic file name resolvers
--- that must be overloaded by the user (i. e. us).
assert(luaotfload_module, "This is a part of luaotfload and should not be loaded independently") {
name = "luaotfload-resolvers",
version = "3.17", --TAGVERSION
date = "2021-01-08", --TAGDATE
description = "luaotfload submodule / resolvers",
license = "GPL v2.0"
}
if not lualibs then error "this module requires Luaotfload" end
if not luaotfload then error "this module requires Luaotfload" end
--[[doc--
Relying on the \verb|name:| resolver for everything has been the
source of permanent trouble with the database.
With the introduction of the new syntax parser we now have enough
granularity to distinguish between the \XETEX emulation layer and
the genuine \verb|name:| and \verb|file:| lookups of \LUATEX-Fonts.
Another benefit is that we can now easily plug in or replace new
lookup behaviors if necessary.
The name resolver remains untouched, but it calls
\luafunction{fonts.names.resolve()} internally anyways (see
\fileent{luaotfload-database.lua}).
--doc]]--
local next = next
local tableconcat = table.concat
local kpsefind_file = kpse.find_file
local lfsisfile = lfs.isfile
local stringlower = string.lower
local stringformat = string.format
local filesuffix = file.suffix
local fileremovesuffix = file.removesuffix
local luatexbase = luatexbase
local logreport = luaotfload.log.report
--[[doc--
\identifier{luaotfload} promises easy access to system fonts.
Without additional precautions, this cannot be achieved by
\identifier{kpathsea} alone, because it searches only the
\fileent{texmf} directories by default.
Although it is possible for \identifier{kpathsea} to include extra
paths by adding them to the \verb|OSFONTDIR| environment variable,
this is still short of the goal »\emphasis{it just works!}«.
When building the font database \identifier{luaotfload} scans
system font directories anyways, so we already have all the
information for looking sytem fonts.
With the release version 2.2 the file names are indexed in the
database as well and we are ready to resolve \verb|file:| lookups
this way.
Thus we no longer need to call the \identifier{kpathsea} library in
most cases when looking up font files, only when generating the
database, and when verifying the existence of a file in the
\fileent{texmf} tree.
--doc]]--
local function resolve_file (specification)
local name, _format, success = fonts.names.lookup_font_file (specification.name)
if success then return name end
logreport ("log", 1, "resolve", "file lookup of %q unsuccessful", name)
end
--[[doc--
Prior to version 2.2, \identifier{luaotfload} did not distinguish
\verb|file:| and \verb|path:| lookups, causing complications with
the resolver.
Now we test if the requested name is an absolute path in the file
system, otherwise we fall back to the \verb|file:| lookup.
--doc]]--
local function resolve_path (specification)
local name = specification.name
if lfsisfile (name) then return name end
logreport ("log", 1, "resolve",
"path lookup of %q unsuccessful, falling back to file:",
name)
return resolve_file (specification)
end
--[[doc--
The \verb|name:| resolver.
--doc]]--
--- fonts.names.resolvers.name -- Customized version of the
--- generic name resolver.
local function resolve_name (specification)
local resolver = fonts.names.lookup_font_name_cached
if config.luaotfload.run.resolver == "normal" then
resolver = fonts.names.lookup_font_name
end
local resolved, subfont = resolver (specification)
if resolved then
logreport ("log", 1, "resolve", "name lookup %q -> %q",
specification.name, resolved ..
(subfont and stringformat ("(%d)", subfont) or ""))
return resolved, tonumber(subfont)
end
return resolve_file (specification)
end
--[[doc--
We classify as \verb|anon:| those requests that have neither a
prefix nor brackets. According to Khaled\footnote{%
% XXX dead link‽
\url{https://github.com/phi-gamma/luaotfload/issues/4#issuecomment-17090553}.
}
they are the \XETEX equivalent of a \verb|name:| request, so we
will be treating them as such or, at least, in a similar fashion.
Not distinguishing between “anon” and “name” requests has a serious
drawback: The syntax is overloaded for requesting fonts in
\identifier{Type1} (\abbrev{tfm}, \abbrev{ofm}) format.
These are essentially \verb|file:| lookups and must be caught
before the \verb|name:| resolver kicks in, lest they cause the
database to update.
Even if we were to require the \verb|file:| prefix for all
\identifier{Type1} requests, tests have shown that certain fonts
still include further fonts (e.~g. \fileent{omlgcb.ofm} will ask
for \fileent{omsecob.tfm}) \emphasis{using the old syntax}.
For this reason, we introduce an extra check with an early return.
--doc]]--
local tex_formats = { "tfm", "ofm" }
local resolvers_findfile = luaotfload.fontloader.resolvers.findfile
local function resolve_tex_format (specification)
local name = specification.name
for i=1, #tex_formats do
local format = tex_formats [i]
local resolved = resolvers_findfile(name, format)
if resolved then
return resolved, format
end
end
end
local function resolve_path_if_exists (specification)
local spec = specification.specification
local exists = lfsisfile (spec)
if exists then
--- If this path is taken a file matching the specification
--- literally was found. In this situation, Luaotfload is
--- expected to load that file directly, even though we provide
--- explicit “file” and “path” lookups to address exactly this
--- situation.
logreport ("log", 1, "resolve",
"file %q exists, performing path lookup", spec)
return spec
end
end
--[[doc--
Custom file resolvers via callback.
--doc]]--
local function resolve_my (specification)
return luatexbase.call_callback ("luaotfload.resolve_font", specification)
end
local resolve_methods = {
tex = resolve_tex_format,
path = resolve_path_if_exists,
name = resolve_name,
file = resolve_file,
my = resolve_my,
}
local function resolve_sequence (seq, specification)
for i = 1, #seq do
local id = seq [i]
local mth = resolve_methods [id]
if not mth then
logreport ("both", 0, "resolve",
"step %d: invalid lookup method %q", i, id)
else
logreport ("both", 3, "resolve", "step %d: apply method %q (%s)", i, id, mth)
local result, t = mth (specification)
if result then
logreport ("both", 3, "resolve",
"%d: method %q resolved %q -> %s.",
i, id, specification.specification, result)
return result, t
end
end
end
logreport ("both", 0, "resolve",
"sequence of %d lookups yielded nothing appropriate.", #seq)
end
local default_anon_sequence = {
"tex", "path", "name",
}
local function resolve_anon (specification)
return resolve_sequence (config.luaotfload.run.anon_sequence, specification)
end
--[[doc--
{\bfseries EXPERIMENTAL}:
\identifier{kpse}-only resolver, for those who can do without
system fonts.
--doc]]--
local function resolve_kpse (specification)
local name = specification.name
local suffix = stringlower (filesuffix (name))
if suffix and fonts.formats[suffix] then
local resolved = resolvers_findfile(name, suffix)
if resolved then return resolved end
end
for t, format in next, fonts.formats do --- brute force
local resolved = kpsefind_file (name, format)
if resolved then return resolved, t end
end
end
local lookup_subfont_index = fonts.names.lookup_subfont_index
local function wrap_resolver(resolver)
return function (specification)
local filename, sub, forced = resolver(specification)
if type(sub) ~= "number" then
forced = sub
sub = nil
end
if filename then
specification.resolved = filename
specification.filename = filename
specification.name = filename
specification.sub = sub or specification.sub
if type(specification.sub) == "string" then
specification.sub =
lookup_subfont_index(filename, specification.sub)
end
specification.forced = specification.forced or forced
if not specification.forced then
local suffix = stringlower (filesuffix (filename))
if suffix and fonts.formats[suffix] then
specification.forced = suffix
end
end
if specification.forced then
specification.forcedname = filename
end
return true
end
return false
end
end
local resolvers = table.merge(luaotfload.resolvers, {
path = resolve_path,
name = resolve_name,
anon = resolve_anon,
file = resolve_file,
kpse = resolve_kpse,
my = resolve_my,
})
luaotfload.resolvers = resolvers
return function()
if luatexbase and luatexbase.create_callback then
luatexbase.create_callback ("luaotfload.resolve_font",
"exclusive", function () end)
end
logreport ("log", 5, "resolvers", "installing font resolvers", name)
local request_resolvers = fonts.definers.resolvers
for k, _ in pairs(request_resolvers) do
request_resolvers[k] = nil
end
setmetatable(request_resolvers, {__index = function(t, n)
if not resolvers[n] then return end
local wrapped = wrap_resolver(resolvers[n])
t[n] = wrapped
return wrapped
end})
fonts.formats.ofm = "type1"
fonts.encodings = fonts.encodings or { }
fonts.encodings.known = fonts.encodings.known or { }
return true
end
--- vim:ft=lua:ts=8:sw=4:et:tw=79