diff options
| -rw-r--r-- | luaotfload-database.lua | 310 |
1 files changed, 38 insertions, 272 deletions
diff --git a/luaotfload-database.lua b/luaotfload-database.lua index c3256f0..fec4efa 100644 --- a/luaotfload-database.lua +++ b/luaotfload-database.lua @@ -875,278 +875,6 @@ local add_to_match = function (found, size, face) return found, continue end ---[[doc-- - -Luatex-fonts, the font-loader package luaotfload imports, comes with -basic file location facilities (see luatex-fonts-syn.lua). -However, not only does the builtin functionality rely on Context’s font -name database, it is also too limited to be of more than basic use. -For this reason, luaotfload supplies its own resolvers that accesses -the font database created by the luaotfload-tool script. - ---doc]]-- - - ---- ---- the request specification has the fields: ---- ---- · features: table ---- · normal: set of { ccmp clig itlc kern liga locl mark mkmk rlig } ---- · ??? ---- · forced: string ---- · lookup: "name" ---- · method: string ---- · name: string ---- · resolved: string ---- · size: int ---- · specification: string (== <lookup> ":" <name>) ---- · sub: string ---- ---- The “size” field deserves special attention: if its value is ---- negative, then it actually specifies a scalefactor of the ---- design size of the requested font. This happens e.g. if a font is ---- requested without an explicit “at size”. If the font is part of a ---- larger collection with different design sizes, this complicates ---- matters a bit: Normally, the resolver prefers fonts that have a ---- design size as close as possible to the requested size. If no ---- size specified, then the design size is implied. But which design ---- size should that be? Xetex appears to pick the “normal” (unmarked) ---- size: with Adobe fonts this would be the one that is neither ---- “caption” nor “subhead” nor “display” &c ... For fonts by Adobe this ---- seems to be the one that does not receive a “prefmodifiers” field. ---- (IOW Adobe uses the “prefmodifiers” field to encode the design size ---- in more or less human readable format.) However, this is not true ---- of LM and EB Garamond. As this matters only where there are ---- multiple design sizes to a given font/style combination, we put a ---- workaround in place that chooses that unmarked version. - ---- ---- the first return value of “resolve” is the file name of the ---- requested font (string) ---- the second is of type bool or string and indicates the subfont of a ---- ttc ---- ---- 'a -> 'a -> table -> (string * string | bool * bool) ---- - ---[===[ -resolve = function (_, _, specification) -- the 1st two parameters are used by ConTeXt - if not fonts_loaded then names.data = load_names() end - local data = names.data - - local name = sanitize_fontname (specification.name) - local style = sanitize_fontname (specification.style) or "regular" - - local askedsize - - if specification.optsize then - askedsize = tonumber(specification.optsize) - else - local specsize = specification.size - if specsize and specsize >= 0 then - askedsize = specsize / 65536 - end - end - - if type(data) ~= "table" then - --- this catches a case where load_names() doesn’t - --- return a database object, which can happen only - --- in case there is valid Lua code in the database, - --- but it’s not a table, e.g. it contains an integer. - if not fonts_reloaded then - return reload_db("invalid database; not a table", - resolve, nil, nil, specification) - end - --- unsucessfully reloaded; bail - return specification.name, false, false - end - - if not data.mappings then - if not fonts_reloaded then - return reload_db("invalid database; missing font mapping", - resolve, nil, nil, specification) - end - return specification.name, false, false - end - - local synonym_set = style_synonyms.set - local stylesynonyms = synonym_set[style] - local regularsynonyms = synonym_set.regular - - local exact = { } --> collect exact style matches - local synonymous = { } --> collect matching style synonyms - local fallback --> e.g. non-matching style (fontspec is anal about this) - local candidates = { } --> secondary results, incomplete matches - - for n, face in next, data.mappings do - local family, metafamily - local prefmodifiers, fontstyle_name, subfamily - local psname, fullname, fontname, pfullname - - local facenames = face.sanitized - if facenames then - family = facenames.family - subfamily = facenames.subfamily - fontstyle_name = facenames.fontstyle_name - prefmodifiers = facenames.prefmodifiers or fontstyle_name or subfamily - fullname = facenames.fullname - psname = facenames.psname - fontname = facenames.fontname - pfullname = facenames.pfullname - metafamily = facenames.metafamily - end - fontname = fontname or sanitize_fontname (face.fontname) - pfullname = pfullname or sanitize_fontname (face.fullname) - - if name == family - or name == metafamily - then - if style == prefmodifiers - or style == fontstyle_name - then - local continue - exact, continue = add_to_match(exact, askedsize, face) - if continue == false then break end - elseif style == subfamily then - exact = add_to_match(exact, askedsize, face) - elseif stylesynonyms and stylesynonyms[prefmodifiers] - or regularsynonyms[prefmodifiers] - then - --- treat synonyms for prefmodifiers as first-class - --- (needed to prioritize DejaVu Book over Condensed) - exact = add_to_match(exact, askedsize, face) - elseif name == fullname - or name == pfullname - or name == fontname - or name == psname - then - synonymous = add_to_match(synonymous, askedsize, face) - elseif stylesynonyms and stylesynonyms[subfamily] - or regularsynonyms[subfamily] - then - synonymous = add_to_match(synonymous, askedsize, face) - elseif prefmodifiers == "regular" - or subfamily == "regular" then - fallback = face - else --- mark as last straw but continue - candidates[#candidates+1] = face - end - else - if name == fullname - or name == pfullname - or name == fontname - or name == psname then - local continue - exact, continue = add_to_match(exact, askedsize, face) - if continue == false then break end - end - end - end - - local found - if next(exact) then - found = exact - else - found = synonymous - end - - --- this is a monster - if #found == 1 then - --- “found” is really synonymous with “registered in the db”. - local entry = found[1] - local success, filename, subfont - = get_font_file(data.files.full, entry) - if success == true then - report("log", 0, "resolve", - "Font family='%s', subfamily='%s' found: %s", - name, style, filename - ) - return filename, subfont, true - end - - elseif #found > 1 then - -- we found matching font(s) but not in the requested optical - -- sizes, so we loop through the matches to find the one with - -- least difference from the requested size. - local match - - if askedsize then --- choose by design size - local closest - local least = math.huge -- initial value is infinity - - for i, face in next, found do - local dsnsize = face.size and face.size [1] or 0 - local difference = mathabs (dsnsize - askedsize) - if difference < least then - closest = face - least = difference - end - end - - match = closest - else --- choose “unmarked” match, for Adobe fonts this - --- is the one without a “prefmodifiers” field. - match = found [1] --- fallback - for i, face in next, found do - if not face.sanitized.prefmodifiers then - match = face - break - end - end - end - - local success, filename, subfont - = get_font_file(data.files.full, match) - if success == true then - report("log", 0, "resolve", - "Font family='%s', subfamily='%s' found: %s", - name, style, filename - ) - return filename, subfont, true - end - - elseif fallback then - local success, filename, subfont - = get_font_file(data.files.full, fallback) - if success == true then - report("log", 0, "resolve", - "No exact match for request %s; using fallback", - specification.specification - ) - report("log", 0, "resolve", - "Font family='%s', subfamily='%s' found: %s", - name, style, filename - ) - return filename, subfont, true - end - elseif next(candidates) then - --- pick the first candidate encountered - local entry = candidates[1] - local success, filename, subfont - = get_font_file(data.files.full, entry) - if success == true then - report("log", 0, "resolve", - "Font family='%s', subfamily='%s' found: %s", - name, style, filename - ) - return filename, subfont, true - end - end - - --- no font found so far - if not fonts_reloaded then - --- last straw: try reloading the database - return reload_db( - "unresolved font name: '" .. name .. "'", - resolve, nil, nil, specification - ) - end - - --- else, default to requested name - return specification.name, false, false -end --- resolve() -]===] - local choose_closest = function (distances) local closest = 2^51 local match @@ -1299,6 +1027,44 @@ end The return value is a pair consisting of the file name and the subfont index if appropriate.. + the request specification has the fields: + + · features: table + · normal: set of { ccmp clig itlc kern liga locl mark mkmk rlig } + · ??? + · forced: string + · lookup: "name" + · method: string + · name: string + · resolved: string + · size: int + · specification: string (== <lookup> ":" <name>) + · sub: string + + The “size” field deserves special attention: if its value is + negative, then it actually specifies a scalefactor of the + design size of the requested font. This happens e.g. if a font is + requested without an explicit “at size”. If the font is part of a + larger collection with different design sizes, this complicates + matters a bit: Normally, the resolver prefers fonts that have a + design size as close as possible to the requested size. If no + size specified, then the design size is implied. But which design + size should that be? Xetex appears to pick the “normal” (unmarked) + size: with Adobe fonts this would be the one that is neither + “caption” nor “subhead” nor “display” &c ... For fonts by Adobe this + seems to be the one that does not receive a “prefmodifiers” field. + (IOW Adobe uses the “prefmodifiers” field to encode the design size + in more or less human readable format.) However, this is not true + of LM and EB Garamond. As this matters only where there are + multiple design sizes to a given font/style combination, we put a + workaround in place that chooses that unmarked version. + + The first return value of “resolve_name” is the file name of the + requested font (string). It can be passed to the fullname resolver + get_font_file(). + The second value is either “false” or an integer indicating the + subfont index in a TTC. + --doc]]-- --- table -> string * (int | bool) |