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

local lower = string.lower

local fonts              = fonts
local constructors       = fonts.constructors

local otf                = constructors.handlers.otf
local otffeatures        = constructors.features.otf
local registerotffeature = otffeatures.register

local otftables          = otf.tables or { }
otf.tables               = otftables

local allocate           = utilities.storage.allocate

registerotffeature {
    name        = "features",
    description = "initialization of feature handler",
    default     = true,
}

-- these are later hooked into node and base initializaters

local function setmode(tfmdata,value)
    if value then
        tfmdata.properties.mode = lower(value)
    end
end

otf.modeinitializer = setmode

local function setlanguage(tfmdata,value)
    if value then
        local cleanvalue = lower(value)
        local languages  = otftables and otftables.languages
        local properties = tfmdata.properties
        if not languages then
            properties.language = cleanvalue
        elseif languages[value] then
            properties.language = cleanvalue
        else
            properties.language = "dflt"
        end
    end
end

local function setscript(tfmdata,value)
    if value then
        local cleanvalue = lower(value)
        local scripts    = otftables and otftables.scripts
        local properties = tfmdata.properties
        if not scripts then
            properties.script = cleanvalue
        elseif scripts[value] then
            properties.script = cleanvalue
        else
            properties.script = "dflt"
        end
    end
end

registerotffeature {
    name        = "mode",
    description = "mode",
    initializers = {
        base = setmode,
        node = setmode,
        plug = setmode,
    }
}

registerotffeature {
    name         = "language",
    description  = "language",
    initializers = {
        base = setlanguage,
        node = setlanguage,
        plug = setlanguage,
    }
}

registerotffeature {
    name        = "script",
    description = "script",
    initializers = {
        base = setscript,
        node = setscript,
        plug = setscript,
    }
}

-- here (as also in generic

otftables.featuretypes = allocate {
    gpos_single              = "position",
    gpos_pair                = "position",
    gpos_cursive             = "position",
    gpos_mark2base           = "position",
    gpos_mark2ligature       = "position",
    gpos_mark2mark           = "position",
    gpos_context             = "position",
    gpos_contextchain        = "position",
    gsub_single              = "substitution",
    gsub_multiple            = "substitution",
    gsub_alternate           = "substitution",
    gsub_ligature            = "substitution",
    gsub_context             = "substitution",
    gsub_contextchain        = "substitution",
    gsub_reversecontextchain = "substitution",
    gsub_reversesub          = "substitution",
}

function otffeatures.checkeddefaultscript(featuretype,autoscript,scripts)
    if featuretype == "position" then
        local default = scripts.dflt
        if default then
            if autoscript == "position" or autoscript == true then
                return default
            else
                report_otf("script feature %s not applied, enable default positioning")
            end
        else
            -- no positioning at all
        end
    elseif featuretype == "substitution" then
        local default = scripts.dflt
        if default then
            if autoscript == "substitution" or autoscript == true then
                return default
            end
        end
    end
end

function otffeatures.checkeddefaultlanguage(featuretype,autolanguage,languages)
    if featuretype == "position" then
        local default = languages.dflt
        if default then
            if autolanguage == "position" or autolanguage == true then
                return default
            else
                report_otf("language feature %s not applied, enable default positioning")
            end
        else
            -- no positioning at all
        end
    elseif featuretype == "substitution" then
        local default = languages.dflt
        if default then
            if autolanguage == "substitution" or autolanguage == true then
                return default
            end
        end
    end
end