Merge pull request #260 from phi-gamma/master

add import helper, new directory layout, revised letterspacing, fontloader gone nuts

1 files changed, 275 insertions, 0 deletions

diff --git a/src/fontloader/misc/fontloader-fonts.lua b/src/fontloader/misc/fontloader-fonts.lua
new file mode 100644
index 0000000..678a283
--- /dev/null
+++ b/src/fontloader/misc/fontloader-fonts.lua
@@ -0,0 +1,275 @@
+if not modules then modules = { } end modules ['luatex-fonts'] = {
+    version   = 1.001,
+    comment   = "companion to luatex-fonts.tex",
+    author    = "Hans Hagen, PRAGMA-ADE, Hasselt NL",
+    copyright = "PRAGMA ADE / ConTeXt Development Team",
+    license   = "see context related readme files"
+}
+
+-- The following code isolates the generic context code from already defined or to be defined
+-- namespaces. This is the reference loader for plain tex. This generic code is also used in
+-- luaotfload which is a low level lualatex opentype font loader but somehow has gotten a bit
+-- too generic name / prefix, originally set up and maintained by Khaled Hosny. Currently that
+-- set of derived files is maintained by a larger team lead by Philipp Gesang so when there are
+-- issues with this code in latex, you can best contact him. It might make sense then to first
+-- check if context has the same issue. We do our best to keep the interface as clean as possible.
+--
+-- The code base is rather stable now, especially if you stay away from the non generic code. All
+-- relevant data is organized in tables within the main table of a font instance. There are a few
+-- places where in context other code is plugged in, but this does not affect the core code. Users
+-- can (given that their macro package provides this option) access the font data (characters,
+-- descriptions, properties, parameters, etc) of this main table. The documentation is part of
+-- context. There is also a manual for the helper libraries (maintained as part of the cld manuals).
+--
+-- Future versions will probably have some more specific context code removed, like tracing and
+-- obscure hooks, so that we have a more efficient version (and less files too). So, don't depend
+-- too much on low level code that is meant for context as it can change without notice. We might
+-- also add more helper code here, but that depends to what extend metatex (sidetrack of context)
+-- evolves into a low level layer (depends on time, as usual).
+
+texio.write_nl("")
+texio.write_nl("--------------------------------------------------------------------------------")
+texio.write_nl("The font code has been brought in sync with the context version of 2014.12.01 so")
+texio.write_nl("if things don't work out as expected the interfacing needs to be checked. When")
+texio.write_nl("this works as expected a second upgrade will happen that gives a more complete")
+texio.write_nl("support and another sync with the context code (that new code is currently being")
+texio.write_nl("tested. The base pass is now integrated in the main pass.")
+texio.write_nl("--------------------------------------------------------------------------------")
+texio.write_nl("")
+
+utf = utf or unicode.utf8
+
+-- We have some (global) hooks (for latex):
+
+if not non_generic_context then
+    non_generic_context = { }
+end
+
+if not non_generic_context.luatex_fonts then
+    non_generic_context.luatex_fonts = {
+     -- load_before  = nil,
+     -- load_after   = nil,
+     -- skip_loading = nil,
+    }
+end
+
+if not generic_context then
+    generic_context  = { }
+end
+
+if not generic_context.push_namespaces then
+
+    function generic_context.push_namespaces()
+        texio.write(" <push namespace>")
+        local normalglobal = { }
+        for k, v in next, _G do
+            normalglobal[k] = v
+        end
+        return normalglobal
+    end
+
+    function generic_context.pop_namespaces(normalglobal,isolate)
+        if normalglobal then
+            texio.write(" <pop namespace>")
+            for k, v in next, _G do
+                if not normalglobal[k] then
+                    generic_context[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(generic_context,_G)
+        else
+            texio.write(" <fatal error: invalid pop of generic_context>")
+            os.exit()
+        end
+    end
+
+end
+
+local whatever = generic_context.push_namespaces()
+
+-- We keep track of load time by storing the current time. That way we cannot be accused
+-- of slowing down loading too much. Anyhow, there is no reason for this library to perform
+-- slower in any other package as it does in context.
+--
+-- Please don't update to this version without proper testing. It might be that this version
+-- lags behind stock context and the only formal release takes place around tex live code
+-- freeze.
+
+local starttime = os.gettimeofday()
+
+-- As we don't use the context file searching, we need to initialize the kpse library. As the
+-- progname can be anything we will temporary switch to the context namespace if needed. Just
+-- adding the context paths to the path specification is somewhat faster.
+--
+-- Now, with lua 5.2 being used we might create a special ENV for this.
+
+-- kpse.set_program_name("luatex")
+
+local ctxkpse = nil
+local verbose = true
+
+local function loadmodule(name,continue)
+    local foundname = kpse.find_file(name,"tex") or ""
+    if not foundname then
+        if not ctxkpse then
+            ctxkpse = kpse.new("luatex","context")
+        end
+        foundname = ctxkpse:find_file(name,"tex") or ""
+    end
+    if foundname == "" then
+        if not continue then
+            texio.write_nl(string.format(" <luatex-fonts: unable to locate %s>",name))
+            os.exit()
+        end
+    else
+        if verbose then
+            texio.write(string.format(" <%s>",foundname)) -- no file.basename yet
+        end
+        dofile(foundname)
+    end
+end
+
+if non_generic_context.luatex_fonts.load_before then
+    loadmodule(non_generic_context.luatex_fonts.load_before,true)
+end
+
+if non_generic_context.luatex_fonts.skip_loading ~= true then
+
+    loadmodule('luatex-fonts-merged.lua',true)
+
+    if fonts then
+
+        if not fonts._merge_loaded_message_done_ then
+            texio.write_nl("log", "!")
+            texio.write_nl("log", "! I am using the merged version of 'luatex-fonts.lua' here. If")
+            texio.write_nl("log", "! you run into problems or experience unexpected behaviour, and")
+            texio.write_nl("log", "! if you have ConTeXt installed you can try to delete the file")
+            texio.write_nl("log", "! 'luatex-font-merged.lua' as I might then use the possibly")
+            texio.write_nl("log", "! updated libraries. The merged version is not supported as it")
+            texio.write_nl("log", "! is a frozen instance. Problems can be reported to the ConTeXt")
+            texio.write_nl("log", "! mailing list.")
+            texio.write_nl("log", "!")
+        end
+
+        fonts._merge_loaded_message_done_ = true
+
+    else
+
+        -- The following helpers are a bit overkill but I don't want to mess up context code for the
+        -- sake of general generality. Around version 1.0 there will be an official api defined.
+        --
+        -- So, I will strip these libraries and see what is really needed so that we don't have this
+        -- overhead in the generic modules. The next section is only there for the packager, so stick
+        -- to using luatex-fonts with luatex-fonts-merged.lua and forget about the rest. The following
+        -- list might change without prior notice (for instance because we shuffled code around).
+
+        loadmodule("l-lua.lua")
+        loadmodule("l-lpeg.lua")
+        loadmodule("l-function.lua")
+        loadmodule("l-string.lua")
+        loadmodule("l-table.lua")
+        loadmodule("l-io.lua")
+        loadmodule("l-file.lua")
+        loadmodule("l-boolean.lua")
+        loadmodule("l-math.lua")
+        loadmodule("util-str.lua")
+
+        -- The following modules contain code that is either not used at all outside context or will fail
+        -- when enabled due to lack of other modules.
+
+        -- First we load a few helper modules. This is about the miminum needed to let the font modules do
+        -- their work. Don't depend on their functions as we might strip them in future versions of his
+        -- generic variant.
+
+        loadmodule('luatex-basics-gen.lua')
+        loadmodule('data-con.lua')
+
+        -- We do need some basic node support. The code in there is not for general use as it might change.
+
+        loadmodule('luatex-basics-nod.lua')
+
+        -- Now come the font modules that deal with traditional tex fonts as well as open type fonts. We only
+        -- support OpenType fonts here.
+        --
+        -- The font database file (if used at all) must be put someplace visible for kpse and is not shared
+        -- with context. The mtx-fonts script can be used to genate this file (using the --names option).
+
+        -- In 2013/14 I will merge/move some generic files into luatex-fonts-* files (copies) so that
+        -- intermediate updates of context don't interfere. We can then also use the general merger and
+        -- consider stripping debug code.
+
+        loadmodule('font-ini.lua')
+        loadmodule('font-con.lua')
+        loadmodule('luatex-fonts-enc.lua') -- will load font-age on demand
+        loadmodule('font-cid.lua')
+        loadmodule('font-map.lua')         -- for loading lum file (will be stripped)
+        loadmodule('luatex-fonts-syn.lua') -- deals with font names (synonyms)
+        -- begin of test
+        loadmodule('font-tfm.lua')         -- optional
+        loadmodule('font-afm.lua')         -- optional
+        loadmodule('font-afk.lua')         -- optional
+        -- end of test
+        loadmodule('luatex-fonts-tfm.lua')
+        loadmodule('font-oti.lua')
+        loadmodule('font-otf.lua')
+        loadmodule('font-otb.lua')
+        loadmodule('luatex-fonts-inj.lua')
+        loadmodule('luatex-fonts-ota.lua')
+        loadmodule('luatex-fonts-otn.lua')
+        loadmodule('font-otp.lua')
+        loadmodule('luatex-fonts-lua.lua')
+        loadmodule('font-def.lua')         -- this code (stripped) might end up in luatex-fonts-def.lua
+        loadmodule('luatex-fonts-def.lua')
+        loadmodule('luatex-fonts-ext.lua') -- some extensions
+
+        -- We need to plug into a callback and the following module implements the handlers. Actual plugging
+        -- in happens later.
+
+        loadmodule('luatex-fonts-cbk.lua')
+
+    end
+
+end
+
+if non_generic_context.luatex_fonts.load_after then
+    loadmodule(non_generic_context.luatex_fonts.load_after,true)
+end
+
+resolvers.loadmodule = loadmodule
+
+-- In order to deal with the fonts we need to initialize some callbacks. One can overload them later on if
+-- needed. First a bit of abstraction.
+
+generic_context.callback_ligaturing           = false
+generic_context.callback_kerning              = false
+generic_context.callback_pre_linebreak_filter = nodes.simple_font_handler
+generic_context.callback_hpack_filter         = nodes.simple_font_handler
+generic_context.callback_define_font          = fonts.definers.read
+
+-- The next ones can be done at a different moment if needed. You can create a generic_context namespace
+-- and set no_callbacks_yet to true, load this module, and enable the callbacks later. So, there is really
+-- *no* need to create a alternative for luatex-fonts.lua and luatex-fonts-merged.lua: just load this one
+-- and overload if needed.
+
+if not generic_context.no_callbacks_yet then
+
+ -- callback.register('ligaturing',           generic_context.callback_ligaturing)
+ -- callback.register('kerning',              generic_context.callback_kerning)
+    callback.register('pre_linebreak_filter', generic_context.callback_pre_linebreak_filter)
+    callback.register('hpack_filter',         generic_context.callback_hpack_filter)
+    callback.register('define_font' ,         generic_context.callback_define_font)
+
+end
+
+-- We're done.
+
+texio.write(string.format(" <luatex-fonts.lua loaded in %0.3f seconds>", os.gettimeofday()-starttime))
+
+generic_context.pop_namespaces(whatever)