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-rw-r--r--luaotfload-database.lua310
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)