----------------------------------------------------------------------- -- FILE: luaotfload-fallback.lua -- DESCRIPTION: part of luaotfload / fallback ----------------------------------------------------------------------- assert(luaotfload_module, "This is a part of luaotfload and should not be loaded independently") { name = "luaotfload-fallback", version = "3.17", --TAGVERSION date = "2021-01-08", --TAGDATE description = "luaotfload submodule / fallback", license = "GPL v2.0", author = "Marcel Krüger" } local nodenew = node.direct.new local getfont = font.getfont local setfont = node.direct.setfont local getwhd = node.direct.getwhd local insert_after = node.direct.insert_after local traverse_char = node.direct.traverse_char local protect_glyph = node.direct.protect_glyph local otffeatures = fonts.constructors.newfeatures "otf" -- local normalize = fonts.handlers.otf.features.normalize local definers = fonts.definers local define_font -- = luaotfload.define_font % This is set when the first font is loaded. local fallback_table_fontnames = {} local fallback_table = setmetatable({}, { __index = function(t, name) local names = fallback_table_fontnames[name] if not names then t[name] = false return false end local res = setmetatable({}, { __index = function(tt, size) local lookup = {} for i=#names,1,-1 do local f = define_font(names[i] .. ';-fallback', size) local fid if type(f) == 'table' then fid = font.define(f) definers.register(f, fid) elseif f then fid = f f = font.getfont(fid) end lookup[-i] = f -- Needed for multiscript interactions for uni, _ in next, f.characters do rawset(lookup, uni, fid) end end tt[size] = lookup return lookup end, }) t[name] = res return res end, }) local fallback_lookups = setmetatable({}, { __index = function(t, fid) local f = font.getfont(fid) -- table.tofile('myfont2', f) local res = f and f.fallback_lookup or false if res then res = table.merged(res) for uni in next, f.characters do rawset(res, uni, nil) end end t[fid] = res return res end, }) local function makefallbackfont(tfmdata, _, fallback) local t = fallback_table[fallback] if not t then error(string.format("Unknown fallback table %s", fallback)) end fallback = t[tfmdata.size] local fallback_lookup = {} tfmdata.fallback_lookup = fallback end local glyph_id = node.id'glyph' -- TODO: inherited fonts (combining accents etc.) local function dofallback(head, _, _, _, direction) head = node.direct.todirect(head) local last_fid, last_fallbacks for cur, cid, fid in traverse_char(head) do if fid ~= last_fid then last_fid, last_fallbacks = fid, fallback_lookups[fid] end if last_fallbacks then local new_fid = last_fallbacks[cid] if new_fid then setfont(cur, new_fid) end end end end function luaotfload.add_fallback(name, fonts) define_font = define_font or luaotfload.define_font -- Lazy loading because this file get's loaded before define_font is defined if fonts == nil then fonts = name name = #fallback_table_fontnames + 1 else name = name:lower() end fallback_table_fontnames[name] = fonts fallback_table[name] = nil return name end otffeatures.register { name = "fallback", description = "Fill in missing glyphs from other fonts", manipulators = { node = makefallbackfont, plug = makefallbackfont, }, -- processors = { -- processors would be nice, but they are applied -- -- too late for our purposes -- node = donotdef, -- } } return { process = dofallback, } --- vim:sw=2:ts=2:expandtab:tw=71