diff options
Diffstat (limited to 'luaotfload-features.lua')
| -rw-r--r-- | luaotfload-features.lua | 256 |
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 |