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-rw-r--r--src/luaotfload-features.lua146
1 files changed, 145 insertions, 1 deletions
diff --git a/src/luaotfload-features.lua b/src/luaotfload-features.lua
index 322a020..d212df5 100644
--- a/src/luaotfload-features.lua
+++ b/src/luaotfload-features.lua
@@ -970,7 +970,147 @@ local noflags = { }
local tohash = table.tohash
-local function addfeature(data,feature,specifications)
+local function ancient_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 featureorder = specification.order or { feature }
+ local added = false
+ local featurename = stringformat("ctx_%s_%s",feature,s)
+ local st = { }
+ for t=1,#subtables do
+ local list = subtables[t]
+ local full = stringformat("%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] = tabletohash(v)
+ end
+ end
+ local sequence = {
+ chain = 0,
+ features = { [feature] = askedfeatures },
+ flags = featureflags,
+ name = featurename,
+ order = featureorder,
+ subtables = st,
+ type = featuretype,
+ }
+ if specification.prepend then
+ insert(sequences,1,sequence)
+ else
+ insert(sequences,sequence)
+ end
+ -- 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
+
+local function current_addfeature(data,feature,specifications)
local descriptions = data.descriptions
local resources = data.resources
local features = resources.features
@@ -1344,6 +1484,10 @@ return {
anum = anum_specification,
}
+ --- hack for backwards compat with TL2014 loader
+ local addfeature = otf.version < 2.8 and current_addfeature
+ or ancient_addfeature
+
otf.enhancers.register ("check extra features",
function (data, filename, raw)
for feature, specification in next, extrafeatures do