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-rw-r--r--luaotfload-features.lua256
1 files changed, 246 insertions, 10 deletions
diff --git a/luaotfload-features.lua b/luaotfload-features.lua
index f954e72..0121ede 100644
--- a/luaotfload-features.lua
+++ b/luaotfload-features.lua
@@ -6,6 +6,10 @@ if not modules then modules = { } end modules ["features"] = {
license = "see context related readme files"
}
+local format, insert = string.format, table.insert
+local type, next = type, next
+local lpegmatch = lpeg.match
+
---[[ begin included font-ltx.lua ]]
--- this appears to be based in part on luatex-fonts-def.lua
@@ -226,12 +230,191 @@ end
---[[ end included font-ltx.lua ]]
--[[doc--
-Taken from the most recent branch of luaotfload.
+This uses the code from luatex-fonts-merged (<- font-otc.lua) instead
+of the removed luaotfload-font-otc.lua.
+
+TODO find out how far we get setting features without these lines,
+relying on luatex-fonts only (it *does* handle features somehow, after
+all).
--doc]]--
-local addotffeature = fonts.handlers.otf.addfeature
-local registerotffeature = fonts.handlers.otf.features.register
-local everywhere = { ["*"] = { ["*"] = true } }
+-- we assume that the other otf stuff is loaded already
+
+---[[ begin snippet from font-otc.lua ]]
+local trace_loading = false trackers.register("otf.loading", function(v) trace_loading = v end)
+local report_otf = logs.reporter("fonts","otf loading")
+
+local otf = fonts.handlers.otf
+local registerotffeature = otf.features.register
+local setmetatableindex = table.setmetatableindex
+
+-- In the userdata interface we can not longer tweak the loaded font as
+-- conveniently as before. For instance, instead of pushing extra data in
+-- in the table using the original structure, we now have to operate on
+-- the mkiv representation. And as the fontloader interface is modelled
+-- after fontforge we cannot change that one too much either.
+
+local types = {
+ substitution = "gsub_single",
+ ligature = "gsub_ligature",
+ alternate = "gsub_alternate",
+}
+
+setmetatableindex(types, function(t,k) t[k] = k return k end) -- "key"
+
+local everywhere = { ["*"] = { ["*"] = true } } -- or: { ["*"] = { "*" } }
+local noflags = { }
+
+local function addfeature(data,feature,specifications)
+ local descriptions = data.descriptions
+ local resources = data.resources
+ local lookups = resources.lookups
+ local gsubfeatures = resources.features.gsub
+ if gsubfeatures and gsubfeatures[feature] then
+ -- already present
+ else
+ local sequences = resources.sequences
+ local fontfeatures = resources.features
+ local unicodes = resources.unicodes
+ local lookuptypes = resources.lookuptypes
+ local splitter = lpeg.splitter(" ",unicodes)
+ local done = 0
+ local skip = 0
+ if not specifications[1] then
+ -- so we accept a one entry specification
+ specifications = { specifications }
+ end
+ -- subtables are tables themselves but we also accept flattened singular subtables
+ for s=1,#specifications do
+ local specification = specifications[s]
+ local valid = specification.valid
+ if not valid or valid(data,specification,feature) then
+ local initialize = specification.initialize
+ if initialize then
+ -- when false is returned we initialize only once
+ specification.initialize = initialize(specification) and initialize or nil
+ end
+ local askedfeatures = specification.features or everywhere
+ local subtables = specification.subtables or { specification.data } or { }
+ local featuretype = types[specification.type or "substitution"]
+ local featureflags = specification.flags or noflags
+ local added = false
+ local featurename = format("ctx_%s_%s",feature,s)
+ local st = { }
+ for t=1,#subtables do
+ local list = subtables[t]
+ local full = format("%s_%s",featurename,t)
+ st[t] = full
+ if featuretype == "gsub_ligature" then
+ lookuptypes[full] = "ligature"
+ for code, ligature in next, list do
+ local unicode = tonumber(code) or unicodes[code]
+ local description = descriptions[unicode]
+ if description then
+ local slookups = description.slookups
+ if type(ligature) == "string" then
+ ligature = { lpegmatch(splitter,ligature) }
+ end
+ local present = true
+ for i=1,#ligature do
+ if not descriptions[ligature[i]] then
+ present = false
+ break
+ end
+ end
+ if present then
+ if slookups then
+ slookups[full] = ligature
+ else
+ description.slookups = { [full] = ligature }
+ end
+ done, added = done + 1, true
+ else
+ skip = skip + 1
+ end
+ end
+ end
+ elseif featuretype == "gsub_single" then
+ lookuptypes[full] = "substitution"
+ for code, replacement in next, list do
+ local unicode = tonumber(code) or unicodes[code]
+ local description = descriptions[unicode]
+ if description then
+ local slookups = description.slookups
+ replacement = tonumber(replacement) or unicodes[replacement]
+ if descriptions[replacement] then
+ if slookups then
+ slookups[full] = replacement
+ else
+ description.slookups = { [full] = replacement }
+ end
+ done, added = done + 1, true
+ end
+ end
+ end
+ end
+ end
+ if added then
+ -- script = { lang1, lang2, lang3 } or script = { lang1 = true, ... }
+ for k, v in next, askedfeatures do
+ if v[1] then
+ askedfeatures[k] = table.tohash(v)
+ end
+ end
+ sequences[#sequences+1] = {
+ chain = 0,
+ features = { [feature] = askedfeatures },
+ flags = featureflags,
+ name = featurename,
+ subtables = st,
+ type = featuretype,
+ }
+ -- register in metadata (merge as there can be a few)
+ if not gsubfeatures then
+ gsubfeatures = { }
+ fontfeatures.gsub = gsubfeatures
+ end
+ local k = gsubfeatures[feature]
+ if not k then
+ k = { }
+ gsubfeatures[feature] = k
+ end
+ for script, languages in next, askedfeatures do
+ local kk = k[script]
+ if not kk then
+ kk = { }
+ k[script] = kk
+ end
+ for language, value in next, languages do
+ kk[language] = value
+ end
+ end
+ end
+ end
+ end
+ if trace_loading then
+ report_otf("registering feature %a, affected glyphs %a, skipped glyphs %a",feature,done,skip)
+ end
+ end
+end
+
+otf.enhancers.addfeature = addfeature
+
+local extrafeatures = { }
+
+function otf.addfeature(name,specification)
+ extrafeatures[name] = specification
+end
+
+local function enhance(data,filename,raw)
+ for feature, specification in next, extrafeatures do
+ addfeature(data,feature,specification)
+ end
+end
+
+otf.enhancers.register("check extra features",enhance)
+
+---[[ end snippet from font-otc.lua ]]
local tlig = {
{
@@ -271,9 +454,10 @@ local tlig = {
},
}
-addotffeature("tlig", tlig)
-addotffeature("trep", { }) -- empty, all in tlig now
-local anum_arabic = {
+otf.addfeature("tlig", tlig)
+otf.addfeature("trep", { }) -- empty, all in tlig now
+
+local anum_arabic = { --- these are the same as in font-otc
[0x0030] = 0x0660,
[0x0031] = 0x0661,
[0x0032] = 0x0662,
@@ -286,7 +470,7 @@ local anum_arabic = {
[0x0039] = 0x0669,
}
-local anum_persian = {
+local anum_persian = {--- these are the same as in font-otc
[0x0030] = 0x06F0,
[0x0031] = 0x06F1,
[0x0032] = 0x06F2,
@@ -322,18 +506,70 @@ local anum_specification = {
},
{
type = "substitution",
-features = { arab = { ["*"] = true } },
+ features = { arab = { ["*"] = true } },
data = anum_arabic,
flags = { },
valid = valid,
},
}
-addotffeature("anum",anum_specification)
+--- below the specifications as given in the removed font-otc.lua
+--- the rest was identical to what this file had from the beginning
+--- both make the “anum.tex” test pass anyways
+--
+--local anum_specification = {
+-- {
+-- type = "substitution",
+-- features = { arab = { urd = true, dflt = true } },
+-- data = anum_arabic,
+-- flags = noflags, -- { },
+-- valid = valid,
+-- },
+-- {
+-- type = "substitution",
+-- features = { arab = { urd = true } },
+-- data = anum_persian,
+-- flags = noflags, -- { },
+-- valid = valid,
+-- },
+--}
+--
+otf.addfeature("anum",anum_specification)
registerotffeature {
name = 'anum',
description = 'arabic digits',
}
+if characters.combined then
+
+ local tcom = { }
+
+ local function initialize()
+ characters.initialize()
+ for first, seconds in next, characters.combined do
+ for second, combination in next, seconds do
+ tcom[combination] = { first, second }
+ end
+ end
+ -- return false
+ end
+
+ local tcom_specification = {
+ type = "ligature",
+ features = everywhere,
+ data = tcom,
+ flags = noflags,
+ initialize = initialize,
+ }
+
+ otf.addfeature("tcom",tcom_specification)
+
+ registerotffeature {
+ name = 'tcom',
+ description = 'tex combinations',
+ }
+
+end
+
-- vim:tw=71:sw=4:ts=4:expandtab