path: root/tex/context/base/font-def.lua

if not modules then modules = { } end modules ['font-def'] = {
    version   = 1.001,
    comment   = "companion to font-ini.tex",
    author    = "Hans Hagen, PRAGMA-ADE, Hasselt NL",
    copyright = "PRAGMA ADE / ConTeXt Development Team",
    license   = "see context related readme files"
}

-- check reuse of lmroman1o-regular vs lmr10

--[[ldx--
<p>Here we deal with defining fonts. We do so by intercepting the
default loader that only handles <l n='tfm'/>.</p>
--ldx]]--

fonts        = fonts        or { }
fonts.define = fonts.define or { }
fonts.tfm    = fonts.tfm    or { }
fonts.vf     = fonts.vf     or { }
fonts.used   = fonts.used   or { }

fonts.tfm.version = 1.01
fonts.tfm.cache   = containers.define("fonts", "tfm", fonts.tfm.version, false) -- better in font-tfm

--[[ldx--
<p>Choosing a font by name and specififying its size is only part of the
game. In order to prevent complex commands, <l n='xetex'/> introduced
a method to pass feature information as part of the font name. At the
risk of introducing nasty parsing and compatinility problems, this
syntax was expanded over time.</p>

<p>For the sake of users who have defined fonts using that syntax, we
will support it, but we will provide additional methods as well.
Normally users will not use this direct way, but use a more abstract
interface.</p>
 --ldx]]--

--~ name, kind, features = fonts.features.split_xetex("blabla / B : + lnum ; foo = bar ; - whatever ; whow ; + hans ; test = yes")

fonts.define.method        = 3 -- 1: tfm  2: tfm and if not then afm  3: afm and if not then tfm
fonts.define.auto_afm      = true
fonts.define.auto_otf      = true
fonts.define.specify       = fonts.define.specify or { }
fonts.define.splitsymbols  = ""
fonts.define.methods       = fonts.define.methods or { }

fonts.tfm.fonts            = fonts.tfm.fonts        or { }
fonts.tfm.readers          = fonts.tfm.readers      or { }
fonts.tfm.internalized     = fonts.tfm.internalized or { } -- internal tex numbers
fonts.tfm.id               = fonts.tfm.id           or { } -- font data, maybe use just fonts.ids (faster lookup)

fonts.tfm.readers.sequence = { 'otf', 'ttf', 'afm', 'tfm' }

--[[ldx--
<p>We hardly gain anything when we cache the final (pre scaled)
<l n='tfm'/> table. But it can be handy for debugging.</p>
--ldx]]--

fonts.version = 1.05
fonts.cache   = containers.define("fonts", "def", fonts.version, false)

--[[ldx--
<p>We can prefix a font specification by <type>name:</type> or
<type>file:</type>. The first case will result in a lookup in the
synonym table.</p>

<typing>
[ name: | file: ] identifier [ separator [ specification ] ]
</typing>

<p>The following function split the font specification into components
and prepares a table that will move along as we proceed.</p>
--ldx]]--

function fonts.define.analyze(name, size, id)
    name = name or 'unknown'
    local specification = name
    local lookup, rest = specification:match("^(.-):(.+)$")
    local sub = ""
    if lookup == 'file' or lookup == 'name' then
        name = rest
    else
        lookup = 'file'
    end
    local font, method, detail = name:match("^(.-)(["..fonts.define.splitsymbols.."])(.+)$")
    if method and detail then
        name = font
    else
        method, detail = "", ""
    end
    local mainfont, subfont = name:match("^(.*-)(%(.*-)(%)$")
    if mainfont and subfont then
        name, sub = mainfont, subfont
    end
    size = size or (65536*10)
    return {
        lookup        = lookup,        -- forced type
        specification = specification, -- full specification
        size          = size,          -- size in scaled points or -1000*n
        name          = name,          -- font or filename
        sub           = sub,           -- subfont (eg in ttc)
        method        = method,        -- specification method
        detail        = detail,        -- specification
        resolved      = "",            -- resolved font name
        forced        = "",            -- forced loader
        id            = id,            -- font id
        features      = { },           -- preprocessed features
     -- hash          = nil
     -- filename      = nil,
     -- encoding      = nil,
     -- format        = nil,
    }
end

function fonts.define.register_split(symbol,action)
    fonts.define.splitsymbols = fonts.define.splitsymbols .. "%" .. symbol
    fonts.define.specify[symbol] = action
end

--[[ldx--
<p>A unique hash value is generated by:</p>
--ldx]]--

function fonts.tfm.hash_features(specification)
    if specification.features then
        local t = { }
        local normal = specification.features.normal
        if not table.is_empty(normal) then
            for _, v in pairs(table.sortedkeys(normal)) do
                if v ~= "number" then
                    t[#t+1] = v .. '=' .. tostring(normal[v])
                end
            end
        end
        local vtf = specification.features.vtf
        if not table.is_empty(vtf) then
            for _, v in pairs(table.sortedkeys(vtf)) do
                t[#t+1] = v .. '=' .. tostring(vtf[v])
            end
        end
        if next(t) then
            return table.concat(t,"+")
        end
    end
    return "unknown"
end

--~ function fonts.tfm.hash_instance(specification)
--~     if not specification.hash then
--~         specification.hash = fonts.tfm.hash_features(specification)
--~     end
--~     return specification.hash .. ' @ ' .. tostring(specification.size)
--~ end

fonts.designsizes = { }

--[[ldx--
<p>In principle we can share tfm tables when we are in node for a font, but then
we need to define a font switch as an id/attr switch which is no fun, so in that
case users can best use dynamic features ... so, we will not use that speedup. Okay,
when we get rid of base mode we can optimize even further by sharing, but then we
loose our testcases for <l n='luatex'/>.</p>
--ldx]]--

function fonts.tfm.hash_instance(specification,force)
    local hash, size = specification.hash, specification.size
    if force or not hash then
        hash = fonts.tfm.hash_features(specification)
        specification.hash = hash
    end
    if size < 1000 and fonts.designsizes[hash] then
        size = fonts.tfm.scaled(size, fonts.designsizes[hash])
        specification.size = size
    end
    return hash .. ' @ ' .. tostring(size)
end

--[[ldx--
<p>We can resolve the filename using the next function:</p>
--ldx]]--

function fonts.define.resolve(specification)
    if specification.lookup == 'name' then
        specification.resolved, specification.sub = fonts.names.resolve(specification.name,specification.sub)
        if specification.resolved then
            specification.forced = file.extname(specification.resolved)
            specification.name = file.removesuffix(specification.resolved)
        end
    elseif specification.lookup == 'file' then
        specification.forced = file.extname(specification.name)
        specification.name = file.removesuffix(specification.name)
    end
    if specification.forced == "" then
        specification.forced = nil
    end
    specification.hash = specification.name .. ' @ ' .. fonts.tfm.hash_features(specification)
    if specification.sub and specification.sub ~= "" then
        specification.hash = specification.sub .. ' @ ' .. specification.hash
    end
    return specification
end

--[[ldx--
<p>The main read function either uses a forced reader (as determined by
a lookup) or tries to resolve the name using the list of readers.</p>

<p>We need to cache when possible. We do cache raw tfm data (from <l
n='tfm'/>, <l n='afm'/> or <l n='otf'/>). After that we can cache based
on specificstion (name) and size, that is, <l n='tex'/> only needs a number
for an already loaded fonts. However, it may make sense to cache fonts
before they're scaled as well (store <l n='tfm'/>'s with applied methods
and features). However, there may be a relation between the size and
features (esp in virtual fonts) so let's not do that now.</p>

<p>Watch out, here we do load a font, but we don't prepare the
specification yet.</p>
--ldx]]--

function fonts.tfm.read(specification)
    garbagecollector.push()
    input.starttiming(fonts)
    local hash = fonts.tfm.hash_instance(specification)
    local tfmtable = fonts.tfm.fonts[hash] -- hashes by size !
    if not tfmtable then
        if specification.forced and specification.forced ~= "" then
            tfmtable = fonts.tfm.readers[specification.forced](specification)
            if not tfmtable then
                logs.error("define font",string.format("forced type %s of %s not found",specification.forced,specification.name))
            end
        else
            for _, reader in ipairs(fonts.tfm.readers.sequence) do
                if fonts.tfm.readers[reader] then -- not really needed
                    if fonts.trace then
                        logs.report("define font",string.format("trying type %s for %s with file %s",reader,specification.name,specification.filename or "unknown"))
                    end
                    tfmtable = fonts.tfm.readers[reader](specification)
                    if tfmtable then break end
                end
            end
        end
        if tfmtable then
            if tfmtable.filename and fonts.dontembed[tfmtable.filename] then
                tfmtable.embedding = "no"
            else
                tfmtable.embedding = "subset"
            end
            fonts.tfm.fonts[hash] = tfmtable
            fonts.designsizes[specification.hash] = tfmtable.designsize -- we only know this for sure after loading once
        --~ tfmtable.mode = specification.features.normal.mode or "base"
        end
    end
    input.stoptiming(fonts)
    garbagecollector.pop()
    if not tfmtable then
        logs.error("define font",string.format("font with name %s is not found",specification.name))
    end
    return tfmtable
end

--[[ldx--
<p>For virtual fonts we need a slightly different approach:</p>
--ldx]]--

function fonts.tfm.read_and_define(name,size) -- no id
    local specification = fonts.define.analyze(name,size,nil)
    if specification.method and fonts.define.specify[specification.method] then
        specification = fonts.define.specify[specification.method](specification)
    end
    specification = fonts.define.resolve(specification)
    local hash = fonts.tfm.hash_instance(specification)
    local id = fonts.tfm.internalized[hash]
    if not id then
        local fontdata = fonts.tfm.read(specification)
        if fontdata then
            if not fonts.tfm.internalized[hash] then
                id = font.define(fontdata)
                fonts.tfm.id[id] = fontdata
                fonts.tfm.internalized[hash] = id
                if fonts.trace then
                    logs.report("define font", string.format("at 1 id %s, hash: %s",id,hash))
                end
            else
                id = fonts.tfm.internalized[hash]
            end
        else
            id = 0  -- signal
        end
    end
    return fonts.tfm.id[id], id
end

--[[ldx--
<p>A naive callback could be the following:</p>

<code>
callback.register('define_font', function(name,size,id)
    return fonts.define.read(fonts.define.resolve(fonts.define.analyze(name,size,id)))
end)
</code>
--ldx]]--


--[[ldx--
<p>Next follow the readers. This code was written while <l n='luatex'/>
evolved. Each one has its own way of dealing with its format.</p>
--ldx]]--

function fonts.tfm.readers.opentype(specification,suffix,what)
    if fonts.define.auto_otf then
        local fullname, tfmtable = nil, nil
        fullname = input.findbinfile(texmf.instance,specification.name,suffix) or ""
        if fullname == "" then
            local fb = fonts.names.old_to_new[specification.name]
            if fb then
                fullname = input.findbinfile(texmf.instance,fb,suffix) or ""
            end
        end
        if fullname == "" then
            local fb = fonts.names.new_to_old[specification.name]
            if fb then
                fullname = input.findbinfile(texmf.instance,fb,suffix) or ""
            end
        end
        if fullname ~= "" then
            specification.filename, specification.format = fullname, what -- hm, so we do set the filename, then
            tfmtable = fonts.tfm.read_from_open_type(specification)       -- we need to do it for all matches / todo
        end
        return tfmtable
    else
        return nil
    end
end

function fonts.tfm.readers.otf(specification) return fonts.tfm.readers.opentype(specification,"otf","opentype") end
function fonts.tfm.readers.ttf(specification) return fonts.tfm.readers.opentype(specification,"ttf","truetype") end
function fonts.tfm.readers.ttc(specification) return fonts.tfm.readers.opentype(specification,"ttf","truetype") end -- !!

function fonts.tfm.readers.afm(specification,method)
    local fullname, tfmtable = nil, nil
    method = method or fonts.define.method
    if method == 2 then
        fullname = input.findbinfile(texmf.instance,specification.name,"ofm") or ""
        if fullname == "" then
            tfmtable = fonts.tfm.read_from_afm(specification)
        else -- redundant
            specification.filename = fullname
            tfmtable = fonts.tfm.read_from_tfm(specification)
        end
    elseif method == 3 then -- maybe also findbinfile here
        if fonts.define.auto_afm then
            tfmtable = fonts.tfm.read_from_afm(specification)
        end
    elseif method == 4 then -- maybe also findbinfile here
        tfmtable = fonts.tfm.read_from_afm(specification)
    end
    return tfmtable
end

function fonts.tfm.readers.tfm(specification)
    local fullname, tfmtable = nil, nil
    tfmtable = fonts.tfm.read_from_tfm(specification)
    return tfmtable
end

--[[ldx--
<p>So far we haven't really dealt with features (or whatever we want
to pass along with the font definition. We distinguish the following
situations:</p>
situations:</p>

<code>
name:xetex like specs
name@virtual font spec
name*context specification
</code>

<p>Of course one can always define more.</p>
--ldx]]--

function fonts.define.specify.predefined(specification)
    if specification.detail ~= "" and fonts.define.methods[specification.detail] then
         specification.features.vtf = { preset = specification.detail }
    end
    return specification
end

fonts.define.register_split("@", fonts.define.specify.predefined)

function fonts.define.specify.colonized(specification) -- xetex mode
    local list = { }
    if specification.detail and specification.detail ~= "" then
        local expanded_features = { }
        local function expand(features)
            for _,v in pairs(features:split(";")) do
                expanded_features[#expanded_features+1] = v
            end
        end
        expand(specification.detail)
        for _,v in pairs(expanded_features) do
            local a, b = v:match("^%s*(%S+)%s*=%s*(%S+)%s*$")
            if a and b then
                list[a] = b:is_boolean()
                if type(list[a]) == "nil" then
                    list[a] = b
                end
            else
                local a, b = v:match("^%s*([%+%-]?)%s*(%S+)%s*$")
                if a and b then
                    list[b] = a ~= "-"
                end
            end
        end
    end
    specification.features.normal = list
    return specification
end

function fonts.tfm.make(specification)
    local fvm = fonts.define.methods[specification.features.vtf.preset]
    if fvm then
        return fvm(specification)
    else
        return nil
    end
end

fonts.define.register_split(":", fonts.define.specify.colonized)

fonts.define.specify.context_setups  = fonts.define.specify.context_setups  or { }
fonts.define.specify.context_numbers = fonts.define.specify.context_numbers or { }
fonts.define.specify.synonyms        = fonts.define.specify.synonyms        or { }

input.storage.register(false,"fonts/setups" , fonts.define.specify.context_setups , "fonts.define.specify.context_setups" )
input.storage.register(false,"fonts/numbers", fonts.define.specify.context_numbers, "fonts.define.specify.context_numbers")

--~     local t = aux.settings_to_hash(features)
--~     for k,v in pairs(t) do
--~         k = synonyms[k] or k
--~         t[k] = v:is_boolean()
--~         if type(t[k]) == "nil" then
--~             t[k] = v
--~         end
--~     end

fonts.triggers = fonts.triggers or { }

function fonts.define.specify.preset_context(name,parent,features)
    if features == "" then
        if parent:find("=") then
            features = parent
            parent = ""
        end
    end
    local fds = fonts.define.specify
    local setups, numbers, synonyms = fds.context_setups, fds.context_numbers, fds.synonyms
    local number = (setups[name] and setups[name].number) or 0
    local t = (features == "" and { }) or fonts.otf.meanings.normalize(aux.settings_to_hash(features))
    -- todo: synonyms, and not otf bound
    if parent ~= "" then
        for p in parent:gmatch("[^, ]+") do
            local s = setups[p]
            if s then
                for k,v in pairs(s) do
                    if t[k] == nil then
                        t[k] = v
                    end
                end
            end
        end
    end
    -- these are auto set so in order to prevent redundant definitions
    -- we need to preset them (we hash the features and adding a default
    -- setting during initialization may result in a different hash)
    local default = fonts.otf.features.default
    for k,v in pairs(fonts.triggers) do
        if type(t[v]) == "nil" then
            local vv = default[v]
            if vv then t[v] = vv end
        end
    end
    -- sparse 'm so that we get a better hash and less test (experimental
    -- optimization)
    local tt = { }
    for k,v in pairs(t) do
        if v then tt[k] = v end
    end
    -- needed for dynamic features
    if number == 0 then
        numbers[#numbers+1] = name
        tt.number = #numbers
    else
        tt.number = number
    end
    setups[name] = tt
end

--~ function fonts.define.specify.context_number(name)
--~     local s = fonts.define.specify.context_setups[name]
--~     return (s and s.number) or -1
--~ end

do

    -- here we clone features according to languages

    local default = 0
    local setups  = fonts.define.specify.context_setups
    local numbers = fonts.define.specify.context_numbers

    function fonts.define.specify.context_number(name)
        local t = setups[name]
        if not t then
            return default
        elseif t.auto then
            local lng = tonumber(tex.language)
            local tag = name .. ":" .. lng
            local s = setups[tag]
            if s then
                return s.number or default
            else
                local script, language = languages.association(lng)
                if t.script ~= script or t.language ~= language then
                    local s = table.fastcopy(t)
                    local n = #numbers + 1
                    setups[tag] = s
                    numbers[n] = tag
                    s.number = n
                    s.script = script
                    s.language = language
                    return n
                else
                    setups[tag] = t
                    return t.number or default
                end
            end
        else
            return t.number or default
        end
    end

end

function fonts.define.specify.context_tostring(name,kind,separator,yes,no,strict,omit)
    return aux.hash_to_string(table.merged(fonts[kind].features.default or {},fonts.define.specify.context_setups[name] or {}),separator,yes,no,strict,omit)
end

function fonts.define.specify.split_context(features)
    if fonts.define.specify.context_setups[features] then
        return fonts.define.specify.context_setups[features]
    else -- ? ? ?
        return fonts.define.specify.preset_context("***",features)
    end
end

function fonts.define.specify.starred(features)
    if features.detail and features.detail ~= "" then
        features.features.normal = fonts.define.specify.split_context(features.detail)
    else
        features.features.normal = { }
    end
    return features
end

fonts.define.register_split('*',fonts.define.specify.starred)

--[[ldx--
<p>We need to check for default features. For this we provide
a helper function.</p>
--ldx]]--

function fonts.define.check(features,defaults) -- nb adapts features !
    local done = false
    if table.is_empty(features) then
        features, done = table.fastcopy(defaults), true
    else
        for k,v in pairs(defaults) do
            if features[k] == nil then
                features[k], done = v, true
            end
        end
    end
    return features, done -- done signals a change
end

--[[ldx--
<p>So far the specifyers. Now comes the real definer. Here we cache
based on id's. Here we also intercept the virtual font handler. Since
it evolved stepwise I may rewrite this bit (combine code).</p>

In the previously defined reader (the one resulting in a <l n='tfm'/>
table) we cached the (scaled) instances. Here we cache them again, but
this time based on id. We could combine this in one cache but this does
not gain much. By the way, passing id's back to in the callback was
introduced later in the development.</p>
--ldx]]--

function fonts.define.read(name,size,id)
    local specification = fonts.define.analyze(name,size,id)
    if specification.method and fonts.define.specify[specification.method] then
        specification = fonts.define.specify[specification.method](specification)
    end
    specification = fonts.define.resolve(specification)
    local hash = fonts.tfm.hash_instance(specification)
    if true then
    --~         local fontdata = containers.read(fonts.cache,hash) -- for tracing purposes
    end
    local fontdata = fonts.tfm.internalized[hash] -- id
    if not fontdata then
        if specification.features.vtf and specification.features.vtf.preset then
            fontdata = fonts.tfm.make(specification)
        else
            fontdata = fonts.tfm.read(specification)
            if fontdata then
                fonts.tfm.check_virtual_id(fontdata)
            end
        end
        if true then
        --~             fontdata = containers.write(fonts.cache,hash,fontdata) -- for tracing purposes
        end
        if not fonts.tfm.internalized[hash] then
            fonts.tfm.id[id] = fontdata
            fonts.tfm.internalized[hash] = id
            if fonts.trace then
                logs.report("define font", string.format("at 2 id %s, hash: %s",id,hash))
            end
        else
            fontdata = fonts.tfm.internalized[hash]
        end
    end
    if not fontdata then
        logs.error("define font", string.format("name: %s, loading aborted",specification.name))
    elseif fonts.trace and type(fontdata) == "table" then
        logs.report("use font",string.format("%s font n:%s s:%s b:%s e:%s p:%s f:%s",
            fontdata.type          or "unknown",
            fontdata.name          or "?",
            fontdata.size          or "default",
            fontdata.encodingbytes or "?",
            fontdata.encodingname  or "unicode",
            fontdata.fullname      or "?",
            file.basename(fontdata.filename or "?")))
    end
    return fontdata
end

--~ table.insert(fonts.tfm.readers.sequence,1,'vtf')

--~ function fonts.tfm.readers.vtf(specification)
--~     if specification.features.vtf and specification.features.vtf.preset then
--~         return fonts.tfm.make(specification)
--~     else
--~         return nil
--~     end
--~ end

function fonts.vf.find(name)
    name = file.removesuffix(file.basename(name))
    if fonts.tfm.resolve_vf then
        local format = fonts.logger.format(name)
        if format == 'tfm' or format == 'ofm' then
            if fonts.trace then
                logs.report("define font",string.format("locating vf for %s",name))
            end
            return input.findbinfile(texmf.instance,name,"ovf")
        else
            if fonts.trace then
                logs.report("define font",string.format("vf for %s is already taken care of",name))
            end
            return nil -- ""
        end
    else
        if fonts.trace then
            logs.report("define font",string.format("locating vf for %s",name))
        end
        return input.findbinfile(texmf.instance,name,"ovf")
    end
end

--[[ldx--
<p>We overload both the <l n='tfm'/> and <l n='vf'/> readers.</p>
--ldx]]--

callback.register('define_font' , fonts.define.read)
callback.register('find_vf_file', fonts.vf.find    ) -- not that relevant any more