path: root/Master/texmf-dist/tex/context/base/mkiv/grph-inc.lua

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

-- todo: in pdfe: pdfe.copyappearance(document,objnum)
--
-- local im = createimage { filename = fullname }
-- local on = images.flushobject(im,document.__xrefs__[AP])

-- todo: files are sometimes located twice
-- todo: empty filename or only suffix always false (not found)
-- lowercase types
-- mps tex tmp svg
-- partly qualified
-- dimensions
-- use metatables
-- figures.boxnumber can go as we now can use names
-- avoid push
-- move some to command namespace

--[[
The ConTeXt figure inclusion mechanisms are among the oldest code
in ConTeXt and evolved into a complex whole. One reason is that we
deal with backend in an abstract way. What complicates matters is
that we deal with internal graphics as well: TeX code, MetaPost code,
etc. Later on figure databases were introduced, which resulted in
a plug in model for locating images. On top of that runs a conversion
mechanism (with caching) and resource logging.

Porting that to Lua is not that trivial because quite some
status information is kept between al these stages. Of course, image
reuse also has some price, and so I decided to implement the graphics
inclusion in several layers: detection, loading, inclusion, etc.

Object sharing and scaling can happen at each stage, depending on the
way the resource is dealt with.

The TeX-Lua mix is suboptimal. This has to do with the fact that we cannot
run TeX code from within Lua. Some more functionality will move to Lua.
]]--

-- todo: store loaded pages per pdf file someplace

local tonumber, tostring, next, unpack = tonumber, tostring, next, unpack
local format, lower, find, match, gsub = string.format, string.lower, string.find, string.match, string.gsub
local longtostring = string.longtostring
local contains = table.contains
local sortedhash, sortedkeys = table.sortedhash, table.sortedkeys
local concat, insert, remove = table.concat, table.insert, table.remove
local todimen = string.todimen
local collapsepath = file.collapsepath
local formatters = string.formatters
local odd = math.odd

local P, R, S, Cc, C, Cs, Ct, lpegmatch = lpeg.P, lpeg.R, lpeg.S, lpeg.Cc, lpeg.C, lpeg.Cs, lpeg.Ct, lpeg.match

local settings_to_array = utilities.parsers.settings_to_array
local settings_to_hash  = utilities.parsers.settings_to_hash
local allocate          = utilities.storage.allocate
local setmetatableindex = table.setmetatableindex
local replacetemplate   = utilities.templates.replace

local bpfactor          = number.dimenfactors.bp

images                  = images or { }
local images            = images

local hasscheme         = url.hasscheme
local urlhashed         = url.hashed

local resolveprefix     = resolvers.resolve

local texgetbox         = tex.getbox
local texsetbox         = tex.setbox

local hpack             = node.hpack

local new_latelua       = nodes.pool.latelua

local context           = context

local implement         = interfaces.implement
local variables         = interfaces.variables

local codeinjections    = backends.codeinjections
local nodeinjections    = backends.nodeinjections

local trace_figures     = false  trackers.register  ("graphics.locating",   function(v) trace_figures    = v end)
local trace_bases       = false  trackers.register  ("graphics.bases",      function(v) trace_bases      = v end)
local trace_programs    = false  trackers.register  ("graphics.programs",   function(v) trace_programs   = v end)
local trace_conversion  = false  trackers.register  ("graphics.conversion", function(v) trace_conversion = v end)
local trace_inclusion   = false  trackers.register  ("graphics.inclusion",  function(v) trace_inclusion  = v end)
local trace_usage       = false  trackers.register  ("graphics.usage",      function(v) trace_usage      = v end)

local extra_check       = false  directives.register("graphics.extracheck",    function(v) extra_check    = v end)
local auto_transform    = true   directives.register("graphics.autotransform", function(v) auto_transform = v end)

local report            = logs.reporter("graphics")
local report_inclusion  = logs.reporter("graphics","inclusion")

local f_hash_part       = formatters["%s->%s->%s->%s"]
local f_hash_full       = formatters["%s->%s->%s->%s->%s->%s->%s->%s"]

local v_yes             = variables.yes
local v_global          = variables["global"]
local v_local           = variables["local"]
local v_default         = variables.default
local v_auto            = variables.auto

local maxdimen          = tex.magicconstants.maxdimen -- 0x3FFFFFFF -- 2^30-1

local ctx_doscalefigure            = context.doscalefigure
local ctx_relocateexternalfigure   = context.relocateexternalfigure
local ctx_startfoundexternalfigure = context.startfoundexternalfigure
local ctx_stopfoundexternalfigure  = context.stopfoundexternalfigure
local ctx_dosetfigureobject        = context.dosetfigureobject
local ctx_doboxfigureobject        = context.doboxfigureobject

-- extensions

function checkimage(figure)
    if figure then
        local width  = figure.width or 0
        local height = figure.height or 0
        if width <= 0 or height <= 0 then
            report_inclusion("image %a has bad dimensions (%p,%p), discarding",figure.filename or "?",width,height)
            return false, "bad dimensions"
        end
     -- local xres    = figure.xres
     -- local yres    = figure.yres
        local changes = false
        if height > width then
            if height > maxdimen then
                figure.height = maxdimen
                figure.width  = width * maxdimen/height
                changed       = true
            end
        elseif width > maxdimen then
            figure.width  = maxdimen
            figure.height = height * maxdimen/width
            changed       = true
        end
        if changed then
            report_inclusion("limiting natural dimensions of %a, old %p * %p, new %p * %p",
                figure.filename,width,height,figure.width,figure.height)
        end
        if width >= maxdimen or height >= maxdimen then
            report_inclusion("image %a is too large (%p,%p), discarding",
                figure.filename,width,height)
            return false, "dimensions too large"
        end
        return figure
    end
end

--- begin of mapping / this will become graphics & code|nodeinjections but not this year

local  __img__ = type(img) == "table" and img or { }
images.__img__ =__img__

local imgnew   = __img__.new
local imgscan  = __img__.scan
local imgcopy  = __img__.copy
local imgwrap  = __img__.node
local imgembed = __img__.immediatewrite

if imgnew then
    -- catch (actually we should be less picky in img)
    local __img__new__ = imgnew
    imgnew = function(t)
        t.kind = nil
        return __img__new__(t)
    end
end

updaters.register("backend.update.img",function()
    local img = images.__img__
    imgnew   = img.new
    imgscan  = img.scan
    imgcopy  = img.copy
    imgwrap  = img.wrap
    imgembed = img.embed
end)

local imagekeys  = { -- only relevant ones
    "width", "height", "depth", "bbox",
    "colordepth", "colorspace",
    "filename", "filepath", "visiblefilename",
    "imagetype", "stream",
    "index", "objnum",
    "pagebox", "page", "pages",
    "rotation", "transform",
    "xsize", "ysize", "xres", "yres",
}

local imagesizes = {
    art   = true, bleed = true,  crop = true,
    media = true, none  = true,  trim = true,
}

local imagetypes = { [0] =
    "none",
    "pdf", "png", "jpg", "jp2", "jbig2",
    "stream", "memstream",
}

imagetypes   = table.swapped(imagetypes,imagetypes)

images.keys  = imagekeys
images.types = imagetypes
images.sizes = imagesizes

-- new interface

local function createimage(specification)
    return imgnew(specification)
end

local function copyimage(specification)
    return imgcopy(specification)
end

local function scanimage(specification)
    return imgscan(specification)
end

local function embedimage(specification)
    -- write the image to file
    return imgembed(specification)
end

local function wrapimage(specification)
    -- create an image rule
    return imgwrap(specification)
end

images.create = createimage
images.scan   = scanimage
images.copy   = copyimage
images.wrap   = wrapimage
images.embed  = embedimage

-- now we reimplement img:

img = {
    new                  = createimage,
    scan                 = scanimage,
    copy                 = copyimage,
    node                 = wrapimage,
    write                = function(specification) context(wrapimage(specification)) end,
    immediatewrite       = embedimage,
    immediatewriteobject = function() end, -- not upported, experimental anyway
    boxes                = function() return sortedkeys(imagesizes) end,
    fields               = function() return imagekeys end,
    types                = function() return { unpack(imagetypes,0,#imagetypes) } end,
}

-- end of copies / mapping

local function imagetotable(imgtable)
    if type(imgtable) == "table" then
        return copy(imgtable)
    end
    local result = { }
    for k=1,#imagekeys do
        local key   = imagekeys[k]
        result[key] = imgtable[key]
    end
    return result
end

function images.serialize(i,...)
    return table.serialize(imagetotable(i),...)
end

function images.print(i,...)
    return table.print(imagetotable(i),...)
end

local function checkimagesize(size)
    if size then
        size = gsub(size,"box","")
        return imagesizes[size] and size or "crop"
    else
        return "crop"
    end
end

images.check     = checkimage
images.checksize = checkimagesize
images.totable   = imagetotable

-- local indexed = { }
--
-- function images.ofindex(n)
--     return indexed[n]
-- end

--- we can consider an grph-ini file

figures                 = figures or { }
local figures           = figures

figures.images          = images
figures.boxnumber       = figures.boxnumber or 0
figures.defaultsearch   = true
figures.defaultwidth    = 0
figures.defaultheight   = 0
figures.defaultdepth    = 0
figures.nofprocessed    = 0
figures.nofmissing      = 0
figures.preferquality   = true -- quality over location

local figures_loaded    = allocate()   figures.loaded      = figures_loaded
local figures_used      = allocate()   figures.used        = figures_used
local figures_found     = allocate()   figures.found       = figures_found
local figures_suffixes  = allocate()   figures.suffixes    = figures_suffixes
local figures_patterns  = allocate()   figures.patterns    = figures_patterns
local figures_resources = allocate()   figures.resources   = figures_resources

local existers          = allocate()   figures.existers    = existers
local checkers          = allocate()   figures.checkers    = checkers
local includers         = allocate()   figures.includers   = includers
local converters        = allocate()   figures.converters  = converters
local identifiers       = allocate()   figures.identifiers = identifiers
local programs          = allocate()   figures.programs    = programs

local defaultformat     = "pdf"
local defaultprefix     = "m_k_i_v_"

figures.localpaths = allocate {
    ".", "..", "../.."
}

figures.cachepaths = allocate {
    prefix  = "",
    path    = ".",
    subpath = ".",
}

local figure_paths = allocate(table.copy(figures.localpaths))
figures.paths      = figure_paths

local figures_order =  allocate {
    "pdf", "mps", "jpg", "png", "jp2", "jbig", "svg", "eps", "tif", "gif", "mov", "buffer", "tex", "cld", "auto",
}

local figures_formats = allocate { -- magic and order will move here
    ["pdf"]    = { list = { "pdf" } },
    ["mps"]    = { patterns = { "mps", "%d+" } },
    ["jpg"]    = { list = { "jpg", "jpeg" } },
    ["png"]    = { list = { "png" } },
    ["jp2"]    = { list = { "jp2" } },
    ["jbig"]   = { list = { "jbig", "jbig2", "jb2" } },
    ["svg"]    = { list = { "svg", "svgz" } },
    ["eps"]    = { list = { "eps", "ai" } },
    ["gif"]    = { list = { "gif" } },
    ["tif"]    = { list = { "tif", "tiff" } },
    ["mov"]    = { list = { "mov", "flv", "mp4" } }, -- "avi" is not supported
    ["buffer"] = { list = { "tmp", "buffer", "buf" } },
    ["tex"]    = { list = { "tex" } },
    ["cld"]    = { list = { "cld" } },
    ["auto"]   = { list = { "auto" } },
}

local figures_magics = allocate {
    { format = "png", pattern = P("\137PNG\013\010\026\010") },                   -- 89 50 4E 47 0D 0A 1A 0A,
    { format = "jpg", pattern = P("\255\216\255") },                              -- FF D8 FF
    { format = "jp2", pattern = P("\000\000\000\012\106\080\032\032\013\010"), }, -- 00 00 00 0C 6A 50 20 20 0D 0A },
    { format = "gif", pattern = P("GIF") },
    { format = "pdf", pattern = (1 - P("%PDF"))^0 * P("%PDF") },
}

local figures_native = allocate {
    pdf = true,
    jpg = true,
    jp2 = true,
    png = true,
}

figures.formats = figures_formats -- frozen
figures.magics  = figures_magics  -- frozen
figures.order   = figures_order   -- frozen

-- name checker

local okay = P("m_k_i_v_")

local pattern = (R("az","AZ") * P(":"))^-1 * (                                      -- a-z : | A-Z :
    (okay + R("az","09") + S("_/") - P("_")^2)^1 * (P(".") * R("az")^1)^0 * P(-1) + -- a-z | single _ | /
    (okay + R("az","09") + S("-/") - P("-")^2)^1 * (P(".") * R("az")^1)^0 * P(-1) + -- a-z | single - | /
    (okay + R("AZ","09") + S("_/") - P("_")^2)^1 * (P(".") * R("AZ")^1)^0 * P(-1) + -- A-Z | single _ | /
    (okay + R("AZ","09") + S("-/") - P("-")^2)^1 * (P(".") * R("AZ")^1)^0 * P(-1)   -- A-Z | single - | /
) * Cc(false) + Cc(true)

function figures.badname(name)
    if not name then
        -- bad anyway
    elseif not hasscheme(name) then
        return lpegmatch(pattern,name)
    else
        return lpegmatch(pattern,file.basename(name))
    end
end

logs.registerfinalactions(function()
    local done = false
    if trace_usage and figures.nofprocessed > 0 then
        logs.startfilelogging(report,"names")
        for _, data in sortedhash(figures_found) do
            if done then
                report()
            else
                done = true
            end
            report("asked   : %s",data.askedname)
            if data.found then
                report("format  : %s",data.format)
                report("found   : %s",data.foundname)
                report("used    : %s",data.fullname)
                if data.badname then
                    report("comment : %s","bad name")
                elseif data.comment then
                    report("comment : %s",data.comment)
                end
            else
                report("comment : %s","not found")
            end
        end
        logs.stopfilelogging()
    end
    if figures.nofmissing > 0 and logs.loggingerrors() then
        logs.starterrorlogging(report,"missing figures")
        for _, data in sortedhash(figures_found) do
            report("%w%s",6,data.askedname)
        end
        logs.stoperrorlogging()
    end
end)

-- We can set the order but only indirectly so that we can check for support.

function figures.setorder(list) -- can be table or string
    if type(list) == "string" then
        list = settings_to_array(list)
    end
    if list and #list > 0 then
        figures_order = allocate()
        figures.order = figures_order
        local done = { } -- just to be sure in case the list is generated
        for i=1,#list do
            local l = lower(list[i])
            if figures_formats[l] and not done[l] then
                figures_order[#figures_order+1] = l
                done[l] = true
            end
        end
        report_inclusion("lookup order % a",figures_order)
    else
        -- invalid list
    end
end

local function guessfromstring(str)
    if str then
        for i=1,#figures_magics do
            local pattern = figures_magics[i]
            if lpegmatch(pattern.pattern,str) then
                local format = pattern.format
                if trace_figures then
                    report_inclusion("file %a has format %a",filename,format)
                end
                return format
            end
        end
    end
end

figures.guessfromstring = guessfromstring

function figures.guess(filename)
    local f = io.open(filename,'rb')
    if f then
        local str = f:read(100)
        f:close()
        if str then
            return guessfromstring(str)
        end
    end
end

local function setlookups() -- tobe redone .. just set locals
    figures_suffixes = allocate()
    figures_patterns = allocate()
    for _, format in next, figures_order do
        local data = figures_formats[format]
        local list = data.list
        if list then
            for i=1,#list do
                figures_suffixes[list[i]] = format -- hash
            end
        else
            figures_suffixes[format] = format
        end
        local patterns = data.patterns
        if patterns then
            for i=1,#patterns do
                figures_patterns[#figures_patterns+1] = { patterns[i], format } -- array
            end
        end
    end
    figures.suffixes = figures_suffixes
    figures.patterns = figures_patterns
end

setlookups()

figures.setlookups = setlookups

function figures.registerresource(t)
    local n = #figures_resources + 1
    figures_resources[n] = t
    return n
end

local function register(tag,what,target)
    local data = figures_formats[target] -- resolver etc
    if not data then
        data = { }
        figures_formats[target] = data
    end
    local d = data[tag] -- list or pattern
    if d and not contains(d,what) then
        d[#d+1] = what -- suffix or patternspec
    else
        data[tag] = { what }
    end
    if not contains(figures_order,target) then
        figures_order[#figures_order+1] = target
    end
    setlookups()
end

function figures.registersuffix (suffix, target) register('list',suffix,target) end
function figures.registerpattern(pattern,target) register('pattern',pattern,target) end

implement { name = "registerfiguresuffix",  actions = register, arguments = { "'list'",    "string", "string" } }
implement { name = "registerfigurepattern", actions = register, arguments = { "'pattern'", "string", "string" } }

local last_locationset = last_locationset or nil
local last_pathlist    = last_pathlist    or nil

function figures.setpaths(locationset,pathlist)
    if last_locationset == locationset and last_pathlist == pathlist then
        -- this function can be called each graphic so we provide this optimization
        return
    end
    local t, h = figure_paths, settings_to_hash(locationset)
    if last_locationset ~= locationset then
        -- change == reset (actually, a 'reset' would indeed reset
        if h[v_local] then
            t = table.fastcopy(figures.localpaths or { })
        else
            t = { }
        end
        figures.defaultsearch = h[v_default]
        last_locationset = locationset
    end
    if h[v_global] then
        local list = settings_to_array(pathlist)
        for i=1,#list do
            local s = list[i]
            if not contains(t,s) then
                t[#t+1] = s
            end
        end
    end
    figure_paths  = t
    last_pathlist = pathlist
    figures.paths = figure_paths
    if trace_figures then
        report_inclusion("using locations %a",last_locationset)
        report_inclusion("using paths % a",figure_paths)
    end
end

implement { name = "setfigurepaths", actions = figures.setpaths, arguments = "2 strings" }

-- check conversions and handle it here

function figures.hash(data)
    local status = data and data.status
    return (status and status.hash or tostring(status.private)) or "nohash" -- the <img object>
end

-- interfacing to tex

local function new() -- we could use metatables status -> used -> request but it needs testing
    local request = {
        name       = false,
        label      = false,
        format     = false,
        page       = false,
        width      = false,
        height     = false,
        preview    = false,
        ["repeat"] = false,
        controls   = false,
        display    = false,
        mask       = false,
        conversion = false,
        resolution = false,
        color      = false,
        arguments  = false,
        cache      = false,
        prefix     = false,
        size       = false,
    }
    local used = {
        fullname   = false,
        format     = false,
        name       = false,
        path       = false,
        suffix     = false,
        width      = false,
        height     = false,
    }
    local status = {
        status     = 0,
        converted  = false,
        cached     = false,
        fullname   = false,
        format     = false,
    }
    -- this needs checking because we might check for nil, the test case
    -- is getfiguredimensions which then should return ~= 0
 -- setmetatableindex(status, used)
 -- setmetatableindex(used, request)
    return {
        request = request,
        used    = used,
        status  = status,
    }
end

-- use table.insert|remove

local lastfiguredata = nil -- will be topofstack or last so no { } (else problems with getfiguredimensions)
local callstack      = { }

function figures.initialize(request)
    local figuredata = new()
    if request then
        -- request.width/height are strings and are only used when no natural dimensions
        -- can be determined; at some point the handlers might set them to numbers instead
        local w = tonumber(request.width) or 0
        local h = tonumber(request.height) or 0
        local p = tonumber(request.page) or 0
        request.width  = w > 0 and w or nil
        request.height = h > 0 and h or nil
        --
        request.page      = p > 0 and p or 1
        request.keepopen  = p > 0
        request.size      = checkimagesize(request.size)
        request.object    = request.object == v_yes
        request["repeat"] = request["repeat"] == v_yes
        request.preview   = request.preview == v_yes
        request.cache     = request.cache ~= "" and request.cache
        request.prefix    = request.prefix ~= "" and request.prefix
        request.format    = request.format ~= "" and request.format
        request.compact   = request.compact == v_yes
        table.merge(figuredata.request,request)
    end
    return figuredata
end

function figures.push(request)
    statistics.starttiming(figures)
    local figuredata = figures.initialize(request) -- we could use table.sparse but we set them later anyway
    insert(callstack,figuredata)
    lastfiguredata = figuredata
    return figuredata
end

function figures.pop()
    remove(callstack)
    lastfiguredata = callstack[#callstack] or lastfiguredata
    statistics.stoptiming(figures)
end

function figures.current()
    return callstack[#callstack] or lastfiguredata
end

local function get(category,tag,default)
    local value = lastfiguredata and lastfiguredata[category]
    value = value and value[tag]
    if not value or value == "" or value == true then
        return default or ""
    else
        return value
    end
end

local function setdimensions(box)
    local status = lastfiguredata and lastfiguredata.status
    local used   = lastfiguredata and lastfiguredata.used
    if status and used then
        local b = texgetbox(box)
        local w = b.width
        local h = b.height + b.depth
        status.width  = w
        status.height = h
        used.width    = w
        used.height   = h
        status.status = 10
    end
end

figures.get = get
figures.set = setdimensions

implement { name = "figurestatus",   actions = { get, context }, arguments = { "'status'",  "string", "string" } }
implement { name = "figurerequest",  actions = { get, context }, arguments = { "'request'", "string", "string" } }
implement { name = "figureused",     actions = { get, context }, arguments = { "'used'",    "string", "string" } }

implement { name = "figurefilepath", actions = { get, file.dirname,  context }, arguments = { "'used'", "'fullname'" } }
implement { name = "figurefilename", actions = { get, file.nameonly, context }, arguments = { "'used'", "'fullname'" } }
implement { name = "figurefiletype", actions = { get, file.extname,  context }, arguments = { "'used'", "'fullname'" } }

implement { name = "figuresetdimensions", actions = setdimensions, arguments = { "integer" } }

-- todo: local path or cache path

local function forbiddenname(filename)
    if not filename or filename == "" then
        return false
    end
    local expandedfullname = collapsepath(filename,true)
    local expandedinputname = collapsepath(file.addsuffix(environment.jobfilename,environment.jobfilesuffix),true)
    if expandedfullname == expandedinputname then
        report_inclusion("skipping graphic with same name as input filename %a, enforce suffix",expandedinputname)
        return true
    end
    local expandedoutputname = collapsepath(codeinjections.getoutputfilename(),true)
    if expandedfullname == expandedoutputname then
        report_inclusion("skipping graphic with same name as output filename %a, enforce suffix",expandedoutputname)
        return true
    end
end

local function rejected(specification)
    if extra_check then
        local fullname = specification.fullname
        if fullname and figures_native[file.suffix(fullname)] and not figures.guess(fullname) then
            specification.comment = "probably a bad file"
            specification.found   = false
            specification.error   = true
            report_inclusion("file %a looks bad",fullname)
            return true
        end
    end
end

local function wipe(str)
    if str == "" or str == "default" or str == "unknown" then
        return nil
    else
        return str
    end
end

local function register(askedname,specification)
    if not specification then
        specification = { askedname = askedname, comment = "invalid specification" }
    elseif forbiddenname(specification.fullname) then
        specification = { askedname = askedname, comment = "forbidden name" }
    elseif specification.internal then
        -- no filecheck needed
        specification.found = true
        if trace_figures then
            report_inclusion("format %a internally supported by engine",specification.format)
        end
    elseif not rejected(specification) then
        local format = specification.format
        if format then
            local conversion = wipe(specification.conversion)
            local resolution = wipe(specification.resolution)
            local arguments  = wipe(specification.arguments)
            local newformat  = conversion
            if not newformat or newformat == "" then
                newformat = defaultformat
            end
            if trace_conversion then
                report_inclusion("checking conversion of %a, fullname %a, old format %a, new format %a, conversion %a, resolution %a, arguments %a",
                    askedname,
                    specification.fullname,
                    format,
                    newformat,
                    conversion or "default",
                    resolution or "default",
                    arguments  or ""
                )
            end
            -- quick hack
            local converter = (newformat ~= format or resolution or arguments) and converters[format]
            if converter then
                if converter[newformat] then
                    converter = converter[newformat]
                else
                    newformat = defaultformat
                    if converter[newformat] then
                        converter = converter[newformat]
                    else
                        converter = nil
                        newformat = defaultformat
                    end
                end
            elseif trace_conversion then
                report_inclusion("no converter for %a to %a",format,newformat)
            end
            if converter then
                --
                -- todo: outline as helper function
                --
                local oldname = specification.fullname
                local newpath = file.dirname(oldname)
                local oldbase = file.basename(oldname)
                --
                -- problem: we can have weird filenames, like a.b.c (no suffix) and a.b.c.gif
                -- so we cannot safely remove a suffix (unless we do that for known suffixes)
                --
                -- local newbase = file.removesuffix(oldbase) -- assumes a known suffix
                --
                -- so we now have (also see *):
                --
                local newbase = oldbase
                --
                local fc = specification.cache or figures.cachepaths.path
                if fc and fc ~= "" and fc ~= "." then
                    newpath = gsub(fc,"%*",newpath) -- so cachedir can be "/data/cache/*"
                else
                    newbase = defaultprefix .. newbase
                end
                local subpath = specification.subpath or figures.cachepaths.subpath
                if subpath and subpath ~= "" and subpath ~= "."  then
                    newpath = newpath .. "/" .. subpath
                end
                if not lfs.isdir(newpath) then
                    dir.makedirs(newpath)
                    if not file.is_writable(newpath) then
                        if trace_conversion then
                            report_inclusion("path %a is not writable, forcing conversion path %a",newpath,".")
                        end
                        newpath = "."
                    end
                end
                local prefix = specification.prefix or figures.cachepaths.prefix
                if prefix and prefix ~= "" then
                    newbase = prefix .. newbase
                end
                local hash = ""
                if resolution then
                    hash = hash .. "[r:" .. resolution .. "]"
                end
                if arguments then
                    hash = hash .. "[a:" .. arguments .. "]"
                end
                if hash ~= "" then
                    newbase = newbase .. "_" .. md5.hex(hash)
                end
                --
                -- see *, we had:
                --
                -- local newbase = file.addsuffix(newbase,newformat)
                --
                -- but now have (result of Aditya's web image testing):
                --
                -- as a side effect we can now have multiple fetches with different
                -- original figures_formats, not that it matters much (apart from older conversions
                -- sticking around)
                --
                local newbase = newbase .. "." .. newformat
                local newname = file.join(newpath,newbase)
                oldname = collapsepath(oldname)
                newname = collapsepath(newname)
                local oldtime = lfs.attributes(oldname,'modification') or 0
                local newtime = lfs.attributes(newname,'modification') or 0
                if newtime == 0 or oldtime > newtime then
                    if trace_conversion then
                        report_inclusion("converting %a (%a) from %a to %a",askedname,oldname,format,newformat)
                    end
                    converter(oldname,newname,resolution or "", arguments or "")
                else
                    if trace_conversion then
                        report_inclusion("no need to convert %a (%a) from %a to %a",askedname,oldname,format,newformat)
                    end
                end
                if io.exists(newname) and io.size(newname) > 0 then
                    specification.foundname = oldname
                    specification.fullname  = newname
                    specification.prefix    = prefix
                    specification.subpath   = subpath
                    specification.converted = true
                    format = newformat
                    if not figures_suffixes[format] then
                        -- maybe the new format is lowres.png (saves entry in suffixes)
                        -- so let's do this extra check
                        local suffix = file.suffix(newformat)
                        if figures_suffixes[suffix] then
                            if trace_figures then
                                report_inclusion("using suffix %a as format for %a",suffix,format)
                            end
                            format = suffix
                        end
                    end
specification.format = format
                elseif io.exists(oldname) then
                    report_inclusion("file %a is bugged",oldname)
                    if format and imagetypes[format] then
                        specification.fullname = oldname
                    end
                    specification.converted = false
                    specification.bugged    = true
                end
            end
        end
        if format then
            local found = figures_suffixes[format]
            if not found then
                specification.found = false
                if trace_figures then
                    report_inclusion("format %a is not supported",format)
                end
            elseif imagetypes[format] then
                specification.found = true
                if trace_figures then
                    report_inclusion("format %a natively supported by backend",format)
                end
            else
                specification.found = true -- else no foo.1 mps conversion
                if trace_figures then
                    report_inclusion("format %a supported by output file format",format)
                end
            end
        else
            specification.askedname = askedname
            specification.found     = false
        end
    end
    if specification.found then
        specification.foundname = specification.foundname or specification.fullname
    else
        specification.foundname = nil
    end
    specification.badname   = figures.badname(askedname)
    local askedhash = f_hash_part(
        askedname,
        specification.conversion or "default",
        specification.resolution or "default",
        specification.arguments  or ""
    )
    figures_found[askedhash] = specification
    if not specification.found then
        figures.nofmissing = figures.nofmissing + 1
    end
    return specification
end

local resolve_too = false -- true

local internalschemes = {
    file    = true,
    tree    = true,
    dirfile = true,
    dirtree = true,
}

local function locate(request) -- name, format, cache
    -- not resolvers.cleanpath(request.name) as it fails on a!b.pdf and b~c.pdf
    -- todo: more restricted cleanpath
    local askedname       = request.name or ""
    local askedcache      = request.cache
    local askedconversion = request.conversion
    local askedresolution = request.resolution
    local askedarguments  = request.arguments
    local askedhash       = f_hash_part(
        askedname,
        askedconversion or "default",
        askedresolution or "default",
        askedarguments  or ""
    )
    local foundname       = figures_found[askedhash]
    if foundname then
        return foundname
    end
    --
    --
    local askedformat = request.format
    if not askedformat or askedformat == "" or askedformat == "unknown" then
        askedformat = file.suffix(askedname) or ""
    elseif askedformat == v_auto then
        if trace_figures then
            report_inclusion("ignoring suffix of %a",askedname)
        end
        askedformat = ""
        askedname   = file.removesuffix(askedname)
    end
    -- protocol check
    local hashed = urlhashed(askedname)
    if not hashed then
        -- go on
    elseif internalschemes[hashed.scheme] then
        local path = hashed.path
        if path and path ~= "" then
            askedname = path
        end
    else
        local foundname = resolvers.findbinfile(askedname)
        if not foundname or not lfs.isfile(foundname) then -- foundname can be dummy
            if trace_figures then
                report_inclusion("unknown url %a",askedname)
            end
            -- url not found
            return register(askedname)
        end
        local guessedformat = figures.guess(foundname)
        if askedformat ~= guessedformat then
            if trace_figures then
                report_inclusion("url %a has unknown format",askedname)
            end
            -- url found, but wrong format
            return register(askedname)
        else
            if trace_figures then
                report_inclusion("url %a is resolved to %a",askedname,foundname)
            end
            return register(askedname, {
                askedname  = askedname,
                fullname   = foundname,
                format     = askedformat,
                cache      = askedcache,
                conversion = askedconversion,
                resolution = askedresolution,
                arguments  = askedarguments,
            })
        end
    end
    -- we could use the hashed data instead
    local askedpath = file.is_rootbased_path(askedname)
    local askedbase = file.basename(askedname)
    if askedformat ~= "" then
        askedformat = lower(askedformat)
        if trace_figures then
            report_inclusion("forcing format %a",askedformat)
        end
        local format = figures_suffixes[askedformat]
        if not format then
            for i=1,#figures_patterns do
                local pattern = figures_patterns[i]
                if find(askedformat,pattern[1]) then
                    format = pattern[2]
                    if trace_figures then
                        report_inclusion("asked format %a matches %a",askedformat,pattern[1])
                    end
                    break
                end
            end
        end
        if format then
            local foundname, quitscanning, forcedformat, internal = figures.exists(askedname,format,resolve_too) -- not askedformat
            if foundname then
                return register(askedname, {
                    askedname  = askedname,
                    fullname   = foundname, -- askedname,
                    format     = forcedformat or format,
                    cache      = askedcache,
                 -- foundname  = foundname, -- no
                    conversion = askedconversion,
                    resolution = askedresolution,
                    arguments  = askedarguments,
                    internal   = internal,
                })
            elseif quitscanning then
                return register(askedname)
            end
            askedformat = format -- new per 2013-08-05
        elseif trace_figures then
            report_inclusion("unknown format %a",askedformat)
        end
        if askedpath then
            -- path and type given, todo: strip pieces of path
            local foundname, quitscanning, forcedformat = figures.exists(askedname,askedformat,resolve_too)
            if foundname then
                return register(askedname, {
                    askedname  = askedname,
                    fullname   = foundname, -- askedname,
                    format     = forcedformat or askedformat,
                    cache      = askedcache,
                    conversion = askedconversion,
                    resolution = askedresolution,
                    arguments  = askedarguments,
                })
            end
        else
            -- type given
            for i=1,#figure_paths do
                local path = resolveprefix(figure_paths[i]) -- we resolve (e.g. jobfile:)
                local check = path .. "/" .. askedname
             -- we pass 'true' as it can be an url as well, as the type
             -- is given we don't waste much time
                local foundname, quitscanning, forcedformat = figures.exists(check,askedformat,resolve_too)
                if foundname then
                    return register(check, {
                        askedname  = askedname,
                        fullname   = foundname, -- check,
                        format     = askedformat,
                        cache      = askedcache,
                        conversion = askedconversion,
                        resolution = askedresolution,
                        arguments  = askedarguments,
                    })
                end
            end
            if figures.defaultsearch then
                local check = resolvers.findfile(askedname)
                if check and check ~= "" then
                    return register(askedname, {
                        askedname  = askedname,
                        fullname   = check,
                        format     = askedformat,
                        cache      = askedcache,
                        conversion = askedconversion,
                        resolution = askedresolution,
                        arguments  = askedarguments,
                    })
                end
            end
        end
    elseif askedpath then
        if trace_figures then
            report_inclusion("using rootbased path")
        end
        for i=1,#figures_order do
            local format = figures_order[i]
            local list = figures_formats[format].list or { format }
            for j=1,#list do
                local suffix = list[j]
                local check = file.addsuffix(askedname,suffix)
                local foundname, quitscanning, forcedformat = figures.exists(check,format,resolve_too)
                if foundname then
                    return register(askedname, {
                        askedname  = askedname,
                        fullname   = foundname, -- check,
                        format     = forcedformat or format,
                        cache      = askedcache,
                        conversion = askedconversion,
                        resolution = askedresolution,
                        arguments  = askedarguments,
                    })
                end
            end
        end
    else
        if figures.preferquality then
            if trace_figures then
                report_inclusion("unknown format, quality preferred")
            end
            for j=1,#figures_order do
                local format = figures_order[j]
                local list = figures_formats[format].list or { format }
                for k=1,#list do
                    local suffix = list[k]
                 -- local name = file.replacesuffix(askedbase,suffix)
                    local name = file.replacesuffix(askedname,suffix)
                    for i=1,#figure_paths do
                        local path = resolveprefix(figure_paths[i]) -- we resolve (e.g. jobfile:)
                        local check = path .. "/" .. name
                        local isfile = internalschemes[urlhashed(check).scheme]
                        if not isfile then
                            if trace_figures then
                                report_inclusion("warning: skipping path %a",path)
                            end
                        else
                            local foundname, quitscanning, forcedformat = figures.exists(check,format,resolve_too) -- true)
                            if foundname then
                                return register(askedname, {
                                    askedname  = askedname,
                                    fullname   = foundname, -- check
                                    format     = forcedformat or format,
                                    cache      = askedcache,
                                    conversion = askedconversion,
                                    resolution = askedresolution,
                                    arguments  = askedarguments
                                })
                            end
                        end
                    end
                end
            end
        else -- 'location'
            if trace_figures then
                report_inclusion("unknown format, using path strategy")
            end
            for i=1,#figure_paths do
                local path = resolveprefix(figure_paths[i]) -- we resolve (e.g. jobfile:)
                for j=1,#figures_order do
                    local format = figures_order[j]
                    local list = figures_formats[format].list or { format }
                    for k=1,#list do
                        local suffix = list[k]
                        local check = path .. "/" .. file.replacesuffix(askedbase,suffix)
                        local foundname, quitscanning, forcedformat = figures.exists(check,format,resolve_too)
                        if foundname then
                            return register(askedname, {
                                askedname  = askedname,
                                fullname   = foudname, -- check,
                                format     = forcedformat or format,
                                cache      = askedcache,
                                conversion = askedconversion,
                                resolution = askedresolution,
                                arguments  = askedarguments,
                            })
                        end
                    end
                end
            end
        end
        if figures.defaultsearch then
            if trace_figures then
                report_inclusion("using default tex path")
            end
            for j=1,#figures_order do
                local format = figures_order[j]
                local list = figures_formats[format].list or { format }
                for k=1,#list do
                    local suffix = list[k]
                    local check = resolvers.findfile(file.replacesuffix(askedname,suffix))
                    if check and check ~= "" then
                        return register(askedname, {
                            askedname  = askedname,
                            fullname   = check,
                            format     = format,
                            cache      = askedcache,
                            conversion = askedconversion,
                            resolution = askedresolution,
                            arguments  = askedarguments,
                        })
                    end
                end
            end
        end
    end
    return register(askedname, { -- these two are needed for hashing 'found'
        conversion = askedconversion,
        resolution = askedresolution,
        arguments  = askedarguments,
    })
end

-- -- -- plugins -- -- --

function identifiers.default(data)
    local dr, du, ds = data.request, data.used, data.status
    local l = locate(dr)
    local foundname = l.foundname
    local fullname  = l.fullname or foundname
    if fullname then
        du.format   = l.format or false
        du.fullname = fullname -- can be cached
        ds.fullname = foundname -- original
        ds.format   = l.format
        ds.status   = (l.bugged and 0) or (l.found and 10) or 0
    end
    return data
end

function figures.identify(data)
    data = data or callstack[#callstack] or lastfiguredata
    if data then
        local list = identifiers.list -- defined at the end
        for i=1,#list do
            local identifier = list[i]
            local data = identifier(data)
--             if data and (not data.status and data.status.status > 0) then
            if data and (not data.status and data.status.status > 0) then
                break
            end
        end
    end
    return data
end

function figures.exists(askedname,format,resolve)
    return (existers[format] or existers.generic)(askedname,resolve)
end

function figures.check(data)
    data = data or callstack[#callstack] or lastfiguredata
    return (checkers[data.status.format] or checkers.generic)(data)
end

local used_images = { }

statistics.register("used graphics",function()
    if trace_usage then
        local filename = file.nameonly(environment.jobname) .. "-figures-usage.lua"
        if next(figures_found) then
            local found = { }
            for _, data in sortedhash(figures_found) do
                found[#found+1] = data
                for k, v in next, data do
                    if v == false or v == "" then
                        data[k] = nil
                    end
                end
            end
            for i=1,#used_images do
                local u = used_images[i]
                local s = u.status
                if s then
                    s.status = nil -- doesn't say much here
                    if s.error then
                        u.used = { } -- better show that it's not used
                    end
                end
                for _, t in next, u do
                    for k, v in next, t do
                        if v == false or v == "" or k == "private" then
                            t[k] = nil
                        end
                    end
                end
            end
            table.save(filename,{
                found = found,
                used  = used_images,
            } )
            return format("log saved in '%s'",filename)
        else
            os.remove(filename)
        end
    end
end)

function figures.include(data)
    data = data or callstack[#callstack] or lastfiguredata
    if trace_usage then
        used_images[#used_images+1] = data
    end
    return (includers[data.status.format] or includers.generic)(data)
end

function figures.scale(data) -- will become lua code
    data = data or callstack[#callstack] or lastfiguredata
    ctx_doscalefigure()
    return data
end

function figures.done(data)
    figures.nofprocessed = figures.nofprocessed + 1
    data = data or callstack[#callstack] or lastfiguredata
    local dr, du, ds, nr = data.request, data.used, data.status, figures.boxnumber
    local box = texgetbox(nr)
    ds.width  = box.width
    ds.height = box.height
    -- somehow this fails on some of tacos files
 -- ds.xscale = ds.width /(du.width  or 1)
 -- ds.yscale = ds.height/(du.height or 1)
    -- du.width and du.height can be false
    if du.width and du.height and du.width > 0 and du.height > 0 then
        ds.xscale = ds.width /du.width
        ds.yscale = ds.height/du.height
    elseif du.xsize and du.ysize and du.xsize > 0 and du.ysize > 0 then
        ds.xscale = ds.width /du.xsize
        ds.yscale = ds.height/du.ysize
    else
        ds.xscale = 1
        ds.yscale = 1
    end
    -- sort of redundant but can be limited
    ds.page = ds.page or du.page or dr.page
    return data
end

function figures.dummy(data)
    data = data or callstack[#callstack] or lastfiguredata
    local dr, du, nr = data.request, data.used, figures.boxnumber
    local box  = hpack(node.new("hlist")) -- we need to set the dir (luatex 0.60 buglet)
    du.width   = du.width  or figures.defaultwidth
    du.height  = du.height or figures.defaultheight
    du.depth   = du.depth  or figures.defaultdepth
 -- box.dir    = "TLT"
    box.width  = du.width
    box.height = du.height
    box.depth  = du.depth
    texsetbox(nr,box) -- hm, should be global (to be checked for consistency)
end

-- -- -- generic -- -- --

function existers.generic(askedname,resolve)
    -- not findbinfile
    local result
    if hasscheme(askedname) then
        result = resolvers.findbinfile(askedname)
    elseif lfs.isfile(askedname) then
        result = askedname
    elseif resolve then
        result = resolvers.findbinfile(askedname)
    end
    if not result or result == "" then
        result = false
    end
    if trace_figures then
        if result then
            report_inclusion("%a resolved to %a",askedname,result)
        else
            report_inclusion("%a cannot be resolved",askedname)
        end
    end
    return result
end

-- pdf : 0-3: 0 90 180 270
-- jpeg: 0 unset 1-4: 0 90 180 270 5-8: flipped r/c

local transforms = setmetatableindex (
    {
        ["orientation-1"] = 0, ["R0"]     = 0,
        ["orientation-2"] = 4, ["R0MH"]   = 4,
        ["orientation-3"] = 2, ["R180"]   = 2,
        ["orientation-4"] = 6, ["R0MV"]   = 6,
        ["orientation-5"] = 5, ["R270MH"] = 5,
        ["orientation-6"] = 3, ["R90"]    = 3,
        ["orientation-7"] = 7, ["R90MH"]  = 7,
        ["orientation-8"] = 1, ["R270"]   = 1,
    },
    function(t,k) -- transforms are 0 .. 7
        local v = tonumber(k) or 0
        if v < 0 or v > 7 then
            v = 0
        end
        t[k] = v
        return v
    end
)

local function checktransform(figure,forced)
    if auto_transform then
        local orientation = (forced ~= "" and forced ~= v_auto and forced) or figure.orientation or 0
        local transform   = transforms["orientation-"..orientation]
        figure.transform = transform
        if odd(transform) then
            return figure.height, figure.width
        else
            return figure.width, figure.height
        end
    end
end

local pagecount = { }

function checkers.generic(data)
    local dr, du, ds    = data.request, data.used, data.status
    local name          = du.fullname or "unknown generic"
    local page          = du.page or dr.page
    local size          = dr.size or "crop"
    local color         = dr.color or "natural"
    local mask          = dr.mask or "none"
    local conversion    = dr.conversion
    local resolution    = dr.resolution
    local arguments     = dr.arguments
    local scanimage     = dr.scanimage or scanimage
    local userpassword  = dr.userpassword
    local ownerpassword = dr.ownerpassword
    if not conversion or conversion == "" then
        conversion = "default"
    end
    if not resolution or resolution == "" then
        resolution = "default"
    end
    if not arguments or arguments == "" then
        arguments = "default"
    end
    local hash = f_hash_full(
        name,
        page,
        size,
        color,
        mask,
        conversion,
        resolution,
        arguments
    )
    --
    local figure = figures_loaded[hash]
    if figure == nil then
        figure = createimage {
            filename        = name,
            page            = page,
            pagebox         = dr.size,
            keepopen        = dr.keepopen or false,
            userpassword    = userpassword,
            ownerpassword   = ownerpassword,
         -- visiblefilename = "", -- this prohibits the full filename ending up in the file
        }
        codeinjections.setfigurecolorspace(data,figure)
        codeinjections.setfiguremask(data,figure)
        if figure then
            -- new, bonus check (a bogus check in lmtx)
            if page and page > 1 then
                local f = scanimage {
                    filename      = name,
                    userpassword  = userpassword,
                    ownerpassword = ownerpassword,
                }
                if f and f.page and f.pages < page then
                    report_inclusion("no page %i in %a, using page 1",page,name)
                    page        = 1
                    figure.page = page
                end
            end
            -- till here
            local f, comment = checkimage(scanimage(figure))
            if not f then
                ds.comment = comment
                ds.found   = false
                ds.error   = true
            end
            if figure.attr and not f.attr then
                -- tricky as img doesn't allow it
                f.attr = figure.attr
            end
            figure = f
        end
        local f, d = codeinjections.setfigurealternative(data,figure)
        figure = f or figure
        data   = d or data
        figures_loaded[hash] = figure
        if trace_conversion then
            report_inclusion("new graphic, using hash %a",hash)
        end
    else
        if trace_conversion then
            report_inclusion("existing graphic, using hash %a",hash)
        end
    end
    if figure then
        local width, height = checktransform(figure,dr.transform)
        --
        du.width       = width
        du.height      = height
        du.pages       = figure.pages
        du.depth       = figure.depth or 0
        du.colordepth  = figure.colordepth or 0
        du.xresolution = figure.xres or 0
        du.yresolution = figure.yres or 0
        du.xsize       = figure.xsize or 0
        du.ysize       = figure.ysize or 0
        du.rotation    = figure.rotation or 0    -- in pdf multiples or 90% in jpeg 1
        du.orientation = figure.orientation or 0 -- jpeg 1 2 3 4 (0=unset)
        ds.private     = figure
        ds.hash        = hash
    end
    return data
end

local nofimages = 0
local pofimages = { }

function figures.getrealpage(index)
    return pofimages[index] or 0
end

local function updatepage(specification)
    local n = specification.n
    pofimages[n] = pofimages[n] or tex.count.realpageno -- so when reused we register the first one only
end

function includers.generic(data)
    local dr, du, ds = data.request, data.used, data.status
    -- here we set the 'natural dimensions'
    dr.width     = du.width
    dr.height    = du.height
    local hash   = figures.hash(data)
    local figure = figures_used[hash]
 -- figures.registerresource {
 --     filename = du.fullname,
 --     width    = dr.width,
 --     height   = dr.height,
 -- }
    if figure == nil then
        figure = ds.private -- the img object
        if figure then
            figure = (dr.copyimage or copyimage)(figure)
            if figure then
                figure.width  = dr.width  or figure.width
                figure.height = dr.height or figure.height
            end
        end
        figures_used[hash] = figure
    end
    if figure then
        local nr     = figures.boxnumber
        nofimages    = nofimages + 1
        ds.pageindex = nofimages
        local image  = wrapimage(figure)
        local pager  = new_latelua { action = updatepage, n = nofimages }
        image.next = pager
        pager.prev = image
        local box  = hpack(image)
     -- indexed[figure.index] = figure
        box.width  = figure.width
        box.height = figure.height
        box.depth  = 0
        texsetbox(nr,box)
        ds.objectnumber = figure.objnum
        ctx_relocateexternalfigure()
    end
    return data
end

-- -- -- nongeneric -- -- --

local function checkers_nongeneric(data,command) -- todo: macros and context.*
    local dr, du, ds = data.request, data.used, data.status
    local name = du.fullname or "unknown nongeneric"
    local hash = name
    if dr.object then
        -- hm, bugged ... waiting for an xform interface
        if not objects.data["FIG"][hash] then
            if type(command) == "function" then
                command()
            end
            ctx_dosetfigureobject("FIG",hash)
        end
        ctx_doboxfigureobject("FIG",hash)
    elseif type(command) == "function" then
        command()
    end
    return data
end

local function includers_nongeneric(data)
    return data
end

checkers.nongeneric  = checkers_nongeneric
includers.nongeneric = includers_nongeneric

-- -- -- mov -- -- --

function checkers.mov(data)
    local dr, du, ds = data.request, data.used, data.status
    local width = todimen(dr.width or figures.defaultwidth)
    local height = todimen(dr.height or figures.defaultheight)
    local foundname = du.fullname
    dr.width, dr.height = width, height
    du.width, du.height, du.foundname = width, height, foundname
    if trace_inclusion then
        report_inclusion("including movie %a, width %p, height %p",foundname,width,height)
    end
    -- we need to push the node.write in between ... we could make a shared helper for this
    ctx_startfoundexternalfigure(width .. "sp",height .. "sp")
    context(function()
        nodeinjections.insertmovie {
            width      = width,
            height     = height,
            factor     = bpfactor,
            ["repeat"] = dr["repeat"],
            controls   = dr.controls,
            preview    = dr.preview,
            label      = dr.label,
            foundname  = foundname,
        }
    end)
    ctx_stopfoundexternalfigure()
    return data
end

includers.mov = includers.nongeneric

-- -- -- mps -- -- --

internalschemes.mprun = true

-- mprun.foo.1 mprun.6 mprun:foo.2

local ctx_docheckfiguremprun = context.docheckfiguremprun
local ctx_docheckfiguremps   = context.docheckfiguremps

local function internal(askedname)
    local spec, mprun, mpnum = match(lower(askedname),"mprun([:%.]?)(.-)%.(%d+)")
 -- mpnum = tonumber(mpnum) or 0 -- can be string or number, fed to context anyway
    if spec ~= "" then
        return mprun, mpnum
    else
        return "", mpnum
    end
end

function existers.mps(askedname)
    local mprun, mpnum = internal(askedname)
    if mpnum then
        return askedname, true, "mps", true
    else
        return existers.generic(askedname)
    end
end

function checkers.mps(data)
    local mprun, mpnum = internal(data.used.fullname)
    if mpnum then
        return checkers_nongeneric(data,function() ctx_docheckfiguremprun(mprun,mpnum) end)
    else
        return checkers_nongeneric(data,function() ctx_docheckfiguremps(data.used.fullname) end)
    end
end

includers.mps = includers.nongeneric

-- -- -- tex -- -- --

local ctx_docheckfiguretex = context.docheckfiguretex

function existers.tex(askedname)
    askedname = resolvers.findfile(askedname)
    return askedname ~= "" and askedname or false, true, "tex", true
end

function checkers.tex(data)
    return checkers_nongeneric(data,function() ctx_docheckfiguretex(data.used.fullname) end)
end

includers.tex = includers.nongeneric

-- -- -- buffer -- -- --

local ctx_docheckfigurebuffer = context.docheckfigurebuffer

function existers.buffer(askedname)
    local name = file.nameonly(askedname)
    local okay = buffers.exists(name)
    return okay and name, true, "buffer", true -- always quit scanning
end

function checkers.buffer(data)
    return checkers_nongeneric(data,function() ctx_docheckfigurebuffer(file.nameonly(data.used.fullname)) end)
end

includers.buffers = includers.nongeneric

-- -- -- auto -- -- --

function existers.auto(askedname)
    local name = gsub(askedname, ".auto$", "")
    local format = figures.guess(name)
 -- if format then
 --     report_inclusion("format guess %a for %a",format,name)
 -- else
 --     report_inclusion("format guess for %a is not possible",name)
 -- end
    return format and name, true, format
end

checkers.auto  = checkers.generic
includers.auto = includers.generic

-- -- -- cld -- -- --

local ctx_docheckfigurecld = context.docheckfigurecld

function existers.cld(askedname)
    askedname = resolvers.findfile(askedname)
    return askedname ~= "" and askedname or false, true, "cld", true
end

function checkers.cld(data)
    return checkers_nongeneric(data,function() ctx_docheckfigurecld(data.used.fullname) end)
end

includers.cld = includers.nongeneric

-- -- -- converters -- -- --

setmetatableindex(converters,"table")

-- We keep this helper because it has been around for a while and therefore it can
-- be a depedency in an existing workflow.

function programs.makeoptions(options)
    local to = type(options)
    return (to == "table" and concat(options," ")) or (to == "string" and options) or ""
end

function programs.run(binary,argument,variables)
    local found = nil
    if type(binary) == "table" then
        for i=1,#binary do
            local b = binary[i]
            found = os.which(b)
            if found then
                binary = b
                break
            end
        end
        if not found then
            binary = concat(binary, " | ")
        end
    elseif binary then
        found = os.which(match(binary,"[%S]+"))
    end
    if type(argument) == "table" then
        argument = concat(argument," ") -- for old times sake
    end
    if not found then
        report_inclusion("program %a is not installed",binary or "?")
    elseif not argument or argument == "" then
        report_inclusion("nothing to run, no arguments for program %a",binary)
    else
        -- no need to use the full found filename (found) .. we also don't quote the program
        -- name any longer as in luatex there is too much messing with these names
        local command = format([[%s %s]],binary,replacetemplate(longtostring(argument),variables))
        if trace_conversion or trace_programs then
            report_inclusion("running command: %s",command)
        end
        os.execute(command)
    end
end

-- the rest of the code has been moved to grph-con.lua

-- -- -- bases -- -- --

local bases         = allocate()
figures.bases       = bases

local bases_list    = nil -- index      => { basename, fullname, xmlroot }
local bases_used    = nil -- [basename] => { basename, fullname, xmlroot } -- pointer to list
local bases_found   = nil
local bases_enabled = false

local function reset()
    bases_list    = allocate()
    bases_used    = allocate()
    bases_found   = allocate()
    bases_enabled = false
    bases.list    = bases_list
    bases.used    = bases_used
    bases.found   = bases_found
end

reset()

function bases.use(basename)
    if basename == "reset" then
        reset()
    else
        basename = file.addsuffix(basename,"xml")
        if not bases_used[basename] then
            local t = { basename, nil, nil }
            bases_used[basename] = t
            bases_list[#bases_list+1] = t
            if not bases_enabled then
                bases_enabled = true
                xml.registerns("rlx","http://www.pragma-ade.com/schemas/rlx") -- we should be able to do this per xml file
            end
            if trace_bases then
                report_inclusion("registering base %a",basename)
            end
        end
    end
end

implement { name = "usefigurebase", actions = bases.use, arguments = "string" }

local function bases_find(basename,askedlabel)
    if trace_bases then
        report_inclusion("checking for %a in base %a",askedlabel,basename)
    end
    basename = file.addsuffix(basename,"xml")
    local t = bases_found[askedlabel]
    if t == nil then
        local base = bases_used[basename]
        local page = 0
        if base[2] == nil then
            -- no yet located
            for i=1,#figure_paths do
                local path = resolveprefix(figure_paths[i]) -- we resolve (e.g. jobfile:)
                local xmlfile = path .. "/" .. basename
                if io.exists(xmlfile) then
                    base[2] = xmlfile
                    base[3] = xml.load(xmlfile)
                    if trace_bases then
                        report_inclusion("base %a loaded",xmlfile)
                    end
                    break
                end
            end
        end
        t = false
        if base[2] and base[3] then -- rlx:library
            for e in xml.collected(base[3],"/(*:library|figurelibrary)/*:figure/*:label") do
                page = page + 1
                if xml.text(e) == askedlabel then
                    t = {
                        base   = file.replacesuffix(base[2],"pdf"),
                        format = "pdf",
                        name   = xml.text(e,"../*:file"), -- to be checked
                        page   = page,
                    }
                    bases_found[askedlabel] = t
                    if trace_bases then
                        report_inclusion("figure %a found in base %a",askedlabel,base[2])
                    end
                    return t
                end
            end
            if trace_bases and not t then
                report_inclusion("figure %a not found in base %a",askedlabel,base[2])
            end
        end
    end
    return t
end

-- we can access sequential or by name

local function bases_locate(askedlabel)
    for i=1,#bases_list do
        local entry = bases_list[i]
        local t = bases_find(entry[1],askedlabel,1,true)
        if t then
            return t
        end
    end
    return false
end

function identifiers.base(data)
    if bases_enabled then
        local dr, du, ds = data.request, data.used, data.status
        local fbl = bases_locate(dr.name or dr.label)
        if fbl then
            du.page     = fbl.page
            du.format   = fbl.format
            du.fullname = fbl.base
            ds.fullname = fbl.name
            ds.format   = fbl.format
            ds.page     = fbl.page
            ds.status   = 10
        end
    end
    return data
end

bases.locate = bases_locate
bases.find   = bases_find

identifiers.list = {
    identifiers.base,
    identifiers.default
}

-- tracing

statistics.register("graphics processing time", function()
    local nofprocessed = figures.nofprocessed
    if nofprocessed > 0 then
        local nofnames, nofbadnames = 0, 0
        for hash, data in next, figures_found do
            nofnames = nofnames + 1
            if data.badname then
                nofbadnames = nofbadnames + 1
            end
        end
        return format("%s seconds including tex, %s processed images, %s unique asked, %s bad names",
            statistics.elapsedtime(figures),nofprocessed,nofnames,nofbadnames)
    else
        return nil
    end
end)

-- helper

function figures.applyratio(width,height,w,h) -- width and height are strings and w and h are numbers
    if not width or width == "" then
        if not height or height == "" then
            return figures.defaultwidth, figures.defaultheight
        else
            height = todimen(height)
            if w and h then
                return height * w/h, height
            else
                return figures.defaultwidth, height
            end
        end
    else
        width = todimen(width)
        if not height or height == "" then
            if w and h then
                return width, width * h/w
            else
                return width, figures.defaultheight
            end
        else
            return width, todimen(height)
        end
    end
end

-- example of simple plugins:
--
-- figures.converters.png = {
--     png = function(oldname,newname,resolution)
--         local command = string.format('gm convert -depth 1 "%s" "%s"',oldname,newname)
--         logs.report(string.format("running command %s",command))
--         os.execute(command)
--     end,
-- }

-- local n = "foo.pdf"
-- local d = figures.getinfo(n)
-- if d then
--     for i=1,d.used.pages do
--         local p = figures.getinfo(n,i)
--         if p then
--             local u = p.used
--             print(u.width,u.height,u.orientation)
--         end
--     end
-- end

function figures.getinfo(name,page)
    if type(name) == "string" then
        name = { name = name, page = page }
    end
    if name.name then
        local data = figures.push(name)
        data = figures.identify(data)
        if data.status and data.status.status > 0 then
            data = figures.check(data)
        end
        figures.pop()
        return data
    end
end

function figures.getpdfinfo(name,page,metadata)
    -- not that useful but as we have it for detailed inclusion we can as
    -- we expose it
    if type(name) ~= "table" then
        name = { name = name, page = page, metadata = metadata }
    end
    return codeinjections.getinfo(name)
end

-- interfacing

implement {
    name      = "figure_push",
    scope     = "private",
    actions   = figures.push,
    arguments = {
        {
            { "name" },
            { "label" },
            { "page" },
            { "file" },
            { "size" },
            { "object" },
            { "prefix" },
            { "cache" },
            { "format" },
            { "preset" },
            { "controls" },
            { "resources" },
            { "preview" },
            { "display" },
            { "mask" },
            { "conversion" },
            { "resolution" },
            { "color" },
            { "arguments" },
            { "repeat" },
            { "transform" },
            { "compact" },
            { "width", "dimen" },
            { "height", "dimen" },
            { "userpassword" },
            { "ownerpassword" },
        }
    }
}

-- beware, we get a number passed by default

implement { name = "figure_pop",      scope = "private", actions = figures.pop }
implement { name = "figure_done",     scope = "private", actions = figures.done }
implement { name = "figure_dummy",    scope = "private", actions = figures.dummy }
implement { name = "figure_identify", scope = "private", actions = figures.identify }
implement { name = "figure_scale",    scope = "private", actions = figures.scale }
implement { name = "figure_check",    scope = "private", actions = figures.check }
implement { name = "figure_include",  scope = "private", actions = figures.include }

implement {
    name      = "setfigurelookuporder",
    actions   = figures.setorder,
    arguments = "string"
}

implement {
    name      = "figure_reset",
    scope     = "private",
    arguments = { "integer", "dimen", "dimen" },
    actions   = function(box,width,height)
        figures.boxnumber     = box
        figures.defaultwidth  = width
        figures.defaultheight = height
    end
}

-- require("util-lib-imp-gm")
--
-- figures.converters.tif.pdf = function(oldname,newname,resolution)
--     logs.report("graphics","using gm library to convert %a",oldname)
--     utilities.graphicmagick.convert {
--         inputname  = oldname,
--         outputname = newname,
--     }
-- end
--
-- \externalfigure[t:/sources/hakker1b.tiff]

-- something relatively new:

local registered = { }

local ctx_doexternalfigurerepeat = context.doexternalfigurerepeat

implement {
    name      = "figure_register_page",
    arguments = "3 strings",
    actions   = function(a,b,c)
        registered[#registered+1] = { a, b, c }
        context(#registered)
    end
}

implement {
    name    = "figure_nof_registered_pages",
    actions = function()
        context(#registered)
    end
}

implement {
    name      = "figure_flush_registered_pages",
    arguments = "string",
    actions   = function(n)
        local f = registered[tonumber(n)]
        if f then
            ctx_doexternalfigurerepeat(f[1],f[2],f[3],n)
        end
    end
}