[fontloader] reorganize under the new import scheme

For better orientation, the fontloader tree now contains two
subdirectories into which files have been reorganized:

The two files required at runtime for the fontloader and luaotfload-tool
are:

      × ``fontloader-basics-gen.lua``
      × ``fontloader-fontloader.lua``

They are now kept in the ``src/fontloader/runtime/`` subdirectory.

All other files from upstream are now located in
``src/fontloader/misc``. This includes a number of files that have not
yet been part of Luaotfload. Currently, the *misc* set of files is not
packaged along with Luaotfload. This may change in the future when there
is an option to switch the merged fontloader for its constituent files,
or even for upstream.

1 files changed, 1042 insertions, 0 deletions

diff --git a/src/fontloader/misc/fontloader-font-afm.lua b/src/fontloader/misc/fontloader-font-afm.lua
new file mode 100644
index 0000000..ca5616a
--- /dev/null
+++ b/src/fontloader/misc/fontloader-font-afm.lua
@@ -0,0 +1,1042 @@
+if not modules then modules = { } end modules ['font-afm'] = {
+    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"
+}
+
+--[[ldx--
+<p>Some code may look a bit obscure but this has to do with the
+fact that we also use this code for testing and much code evolved
+in the transition from <l n='tfm'/> to <l n='afm'/> to <l
+n='otf'/>.</p>
+
+<p>The following code still has traces of intermediate font support
+where we handles font encodings. Eventually font encoding goes
+away.</p>
+
+<p>The embedding of a font involves creating temporary files and
+depending on your system setup that can fail. It took more than a
+day to figure out why sometimes embedding failed in mingw luatex
+where running on a real path like c:\... failed while running on
+say e:\... being a link worked well. The native windows binaries
+don't have this issue.</p>
+
+--ldx]]--
+
+local fonts, logs, trackers, containers, resolvers = fonts, logs, trackers, containers, resolvers
+
+local next, type, tonumber = next, type, tonumber
+local format, match, gmatch, lower, gsub, strip = string.format, string.match, string.gmatch, string.lower, string.gsub, string.strip
+local abs = math.abs
+local P, S, C, R, lpegmatch, patterns = lpeg.P, lpeg.S, lpeg.C, lpeg.R, lpeg.match, lpeg.patterns
+local derivetable = table.derive
+
+local trace_features     = false  trackers.register("afm.features",   function(v) trace_features = v end)
+local trace_indexing     = false  trackers.register("afm.indexing",   function(v) trace_indexing = v end)
+local trace_loading      = false  trackers.register("afm.loading",    function(v) trace_loading  = v end)
+local trace_defining     = false  trackers.register("fonts.defining", function(v) trace_defining = v end)
+
+local report_afm         = logs.reporter("fonts","afm loading")
+
+local setmetatableindex  = table.setmetatableindex
+
+local findbinfile        = resolvers.findbinfile
+
+local definers           = fonts.definers
+local readers            = fonts.readers
+local constructors       = fonts.constructors
+
+local afm                = constructors.newhandler("afm")
+local pfb                = constructors.newhandler("pfb")
+
+local afmfeatures        = constructors.newfeatures("afm")
+local registerafmfeature = afmfeatures.register
+
+afm.version              = 1.500 -- incrementing this number one up will force a re-cache
+afm.cache                = containers.define("fonts", "afm", afm.version, true)
+afm.autoprefixed         = true -- this will become false some day (catches texnansi-blabla.*)
+
+afm.helpdata             = { }  -- set later on so no local for this
+afm.syncspace            = true -- when true, nicer stretch values
+afm.addligatures         = true -- best leave this set to true
+afm.addtexligatures      = true -- best leave this set to true
+afm.addkerns             = true -- best leave this set to true
+
+local overloads          = fonts.mappings.overloads
+
+local applyruntimefixes  = fonts.treatments and fonts.treatments.applyfixes
+
+local function setmode(tfmdata,value)
+    if value then
+        tfmdata.properties.mode = lower(value)
+    end
+end
+
+registerafmfeature {
+    name         = "mode",
+    description  = "mode",
+    initializers = {
+        base = setmode,
+        node = setmode,
+    }
+}
+
+--[[ldx--
+<p>We start with the basic reader which we give a name similar to the
+built in <l n='tfm'/> and <l n='otf'/> reader.</p>
+--ldx]]--
+
+--~ Comment FONTIDENTIFIER LMMATHSYMBOLS10
+--~ Comment CODINGSCHEME TEX MATH SYMBOLS
+--~ Comment DESIGNSIZE 10.0 pt
+--~ Comment CHECKSUM O 4261307036
+--~ Comment SPACE 0 plus 0 minus 0
+--~ Comment QUAD 1000
+--~ Comment EXTRASPACE 0
+--~ Comment NUM 676.508 393.732 443.731
+--~ Comment DENOM 685.951 344.841
+--~ Comment SUP 412.892 362.892 288.889
+--~ Comment SUB 150 247.217
+--~ Comment SUPDROP 386.108
+--~ Comment SUBDROP 50
+--~ Comment DELIM 2390 1010
+--~ Comment AXISHEIGHT 250
+
+local comment = P("Comment")
+local spacing = patterns.spacer  -- S(" \t")^1
+local lineend = patterns.newline -- S("\n\r")
+local words   = C((1 - lineend)^1)
+local number  = C((R("09") + S("."))^1) / tonumber * spacing^0
+local data    = lpeg.Carg(1)
+
+local pattern = ( -- needs testing ... not used anyway as we no longer need math afm's
+    comment * spacing *
+        (
+            data * (
+                ("CODINGSCHEME" * spacing * words                                      ) / function(fd,a)                                      end +
+                ("DESIGNSIZE"   * spacing * number * words                             ) / function(fd,a)     fd[ 1]                 = a       end +
+                ("CHECKSUM"     * spacing * number * words                             ) / function(fd,a)     fd[ 2]                 = a       end +
+                ("SPACE"        * spacing * number * "plus" * number * "minus" * number) / function(fd,a,b,c) fd[ 3], fd[ 4], fd[ 5] = a, b, c end +
+                ("QUAD"         * spacing * number                                     ) / function(fd,a)     fd[ 6]                 = a       end +
+                ("EXTRASPACE"   * spacing * number                                     ) / function(fd,a)     fd[ 7]                 = a       end +
+                ("NUM"          * spacing * number * number * number                   ) / function(fd,a,b,c) fd[ 8], fd[ 9], fd[10] = a, b, c end +
+                ("DENOM"        * spacing * number * number                            ) / function(fd,a,b  ) fd[11], fd[12]         = a, b    end +
+                ("SUP"          * spacing * number * number * number                   ) / function(fd,a,b,c) fd[13], fd[14], fd[15] = a, b, c end +
+                ("SUB"          * spacing * number * number                            ) / function(fd,a,b)   fd[16], fd[17]         = a, b    end +
+                ("SUPDROP"      * spacing * number                                     ) / function(fd,a)     fd[18]                 = a       end +
+                ("SUBDROP"      * spacing * number                                     ) / function(fd,a)     fd[19]                 = a       end +
+                ("DELIM"        * spacing * number * number                            ) / function(fd,a,b)   fd[20], fd[21]         = a, b    end +
+                ("AXISHEIGHT"   * spacing * number                                     ) / function(fd,a)     fd[22]                 = a       end
+            )
+          + (1-lineend)^0
+        )
+  + (1-comment)^1
+)^0
+
+local function scan_comment(str)
+    local fd = { }
+    lpegmatch(pattern,str,1,fd)
+    return fd
+end
+
+-- On a rainy day I will rewrite this in lpeg ... or we can use the (slower) fontloader
+-- as in now supports afm/pfb loading but it's not too bad to have different methods
+-- for testing approaches.
+
+local keys = { }
+
+function keys.FontName    (data,line) data.metadata.fontname     = strip    (line) -- get rid of spaces
+                                      data.metadata.fullname     = strip    (line) end
+function keys.ItalicAngle (data,line) data.metadata.italicangle  = tonumber (line) end
+function keys.IsFixedPitch(data,line) data.metadata.isfixedpitch = toboolean(line,true) end
+function keys.CharWidth   (data,line) data.metadata.charwidth    = tonumber (line) end
+function keys.XHeight     (data,line) data.metadata.xheight      = tonumber (line) end
+function keys.Descender   (data,line) data.metadata.descender    = tonumber (line) end
+function keys.Ascender    (data,line) data.metadata.ascender     = tonumber (line) end
+function keys.Comment     (data,line)
+ -- Comment DesignSize 12 (pts)
+ -- Comment TFM designsize: 12 (in points)
+    line = lower(line)
+    local designsize = match(line,"designsize[^%d]*(%d+)")
+    if designsize then data.metadata.designsize = tonumber(designsize) end
+end
+
+local function get_charmetrics(data,charmetrics,vector)
+    local characters = data.characters
+    local chr, ind = { }, 0
+    for k,v in gmatch(charmetrics,"([%a]+) +(.-) *;") do
+        if k == 'C'  then
+            v = tonumber(v)
+            if v < 0 then
+                ind = ind + 1 -- ?
+            else
+                ind = v
+            end
+            chr = {
+                index = ind
+            }
+        elseif k == 'WX' then
+            chr.width = tonumber(v)
+        elseif k == 'N'  then
+            characters[v] = chr
+        elseif k == 'B'  then
+            local llx, lly, urx, ury = match(v,"^ *(.-) +(.-) +(.-) +(.-)$")
+            chr.boundingbox = { tonumber(llx), tonumber(lly), tonumber(urx), tonumber(ury) }
+        elseif k == 'L'  then
+            local plus, becomes = match(v,"^(.-) +(.-)$")
+            local ligatures = chr.ligatures
+            if ligatures then
+                ligatures[plus] = becomes
+            else
+                chr.ligatures = { [plus] = becomes }
+            end
+        end
+    end
+end
+
+local function get_kernpairs(data,kernpairs)
+    local characters = data.characters
+    for one, two, value in gmatch(kernpairs,"KPX +(.-) +(.-) +(.-)\n") do
+        local chr = characters[one]
+        if chr then
+            local kerns = chr.kerns
+            if kerns then
+                kerns[two] = tonumber(value)
+            else
+                chr.kerns = { [two] = tonumber(value) }
+            end
+        end
+    end
+end
+
+local function get_variables(data,fontmetrics)
+    for key, rest in gmatch(fontmetrics,"(%a+) *(.-)[\n\r]") do
+        local keyhandler = keys[key]
+        if keyhandler then
+            keyhandler(data,rest)
+        end
+    end
+end
+
+local function get_indexes(data,pfbname)
+    data.resources.filename = resolvers.unresolve(pfbname) -- no shortcut
+    local pfbblob = fontloader.open(pfbname)
+    if pfbblob then
+        local characters = data.characters
+        local pfbdata = fontloader.to_table(pfbblob)
+        if pfbdata then
+            local glyphs = pfbdata.glyphs
+            if glyphs then
+                if trace_loading then
+                    report_afm("getting index data from %a",pfbname)
+                end
+                for index, glyph in next, glyphs do
+            --  for index, glyph in table.sortedhash(glyphs) do
+                    local name = glyph.name
+                    if name then
+                        local char = characters[name]
+                        if char then
+                            if trace_indexing then
+                                report_afm("glyph %a has index %a",name,index)
+                            end
+                            char.index = index
+                        end
+                    end
+                end
+            elseif trace_loading then
+                report_afm("no glyph data in pfb file %a",pfbname)
+            end
+        elseif trace_loading then
+            report_afm("no data in pfb file %a",pfbname)
+        end
+        fontloader.close(pfbblob)
+    elseif trace_loading then
+        report_afm("invalid pfb file %a",pfbname)
+    end
+end
+
+local function readafm(filename)
+    local ok, afmblob, size = resolvers.loadbinfile(filename) -- has logging
+    if ok and afmblob then
+        local data = {
+            resources = {
+                filename = resolvers.unresolve(filename),
+                version  = afm.version,
+                creator  = "context mkiv",
+            },
+            properties = {
+                hasitalics = false,
+            },
+            goodies = {
+            },
+            metadata   = {
+                filename = file.removesuffix(file.basename(filename))
+            },
+            characters = {
+                -- a temporary store
+            },
+            descriptions = {
+                -- the final store
+            },
+        }
+        afmblob = gsub(afmblob,"StartCharMetrics(.-)EndCharMetrics", function(charmetrics)
+            if trace_loading then
+                report_afm("loading char metrics")
+            end
+            get_charmetrics(data,charmetrics,vector)
+            return ""
+        end)
+        afmblob = gsub(afmblob,"StartKernPairs(.-)EndKernPairs", function(kernpairs)
+            if trace_loading then
+                report_afm("loading kern pairs")
+            end
+            get_kernpairs(data,kernpairs)
+            return ""
+        end)
+        afmblob = gsub(afmblob,"StartFontMetrics%s+([%d%.]+)(.-)EndFontMetrics", function(version,fontmetrics)
+            if trace_loading then
+                report_afm("loading variables")
+            end
+            data.afmversion = version
+            get_variables(data,fontmetrics)
+            data.fontdimens = scan_comment(fontmetrics) -- todo: all lpeg, no time now
+            return ""
+        end)
+        return data
+    else
+        if trace_loading then
+            report_afm("no valid afm file %a",filename)
+        end
+        return nil
+    end
+end
+
+--[[ldx--
+<p>We cache files. Caching is taken care of in the loader. We cheat a bit
+by adding ligatures and kern information to the afm derived data. That
+way we can set them faster when defining a font.</p>
+--ldx]]--
+
+local addkerns, addligatures, addtexligatures, unify, normalize, fixnames -- we will implement these later
+
+function afm.load(filename)
+    -- hm, for some reasons not resolved yet
+    filename = resolvers.findfile(filename,'afm') or ""
+    if filename ~= "" and not fonts.names.ignoredfile(filename) then
+        local name = file.removesuffix(file.basename(filename))
+        local data = containers.read(afm.cache,name)
+        local attr = lfs.attributes(filename)
+        local size, time = attr.size or 0, attr.modification or 0
+        --
+        local pfbfile = file.replacesuffix(name,"pfb")
+        local pfbname = resolvers.findfile(pfbfile,"pfb") or ""
+        if pfbname == "" then
+            pfbname = resolvers.findfile(file.basename(pfbfile),"pfb") or ""
+        end
+        local pfbsize, pfbtime = 0, 0
+        if pfbname ~= "" then
+            local attr = lfs.attributes(pfbname)
+            pfbsize = attr.size or 0
+            pfbtime = attr.modification or 0
+        end
+        if not data or data.size ~= size or data.time ~= time or data.pfbsize ~= pfbsize or data.pfbtime ~= pfbtime then
+            report_afm("reading %a",filename)
+            data = readafm(filename)
+            if data then
+                if pfbname ~= "" then
+                    get_indexes(data,pfbname)
+                elseif trace_loading then
+                    report_afm("no pfb file for %a",filename)
+                 -- data.resources.filename = "unset" -- better than loading the afm file
+                end
+                report_afm("unifying %a",filename)
+                unify(data,filename)
+                if afm.addligatures then
+                    report_afm("add ligatures")
+                    addligatures(data)
+                end
+                if afm.addtexligatures then
+                    report_afm("add tex ligatures")
+                    addtexligatures(data)
+                end
+                if afm.addkerns then
+                    report_afm("add extra kerns")
+                    addkerns(data)
+                end
+                normalize(data)
+                fixnames(data)
+                report_afm("add tounicode data")
+                fonts.mappings.addtounicode(data,filename)
+                data.size = size
+                data.time = time
+                data.pfbsize = pfbsize
+                data.pfbtime = pfbtime
+                report_afm("saving %a in cache",name)
+                data.resources.unicodes = nil -- consistent with otf but here we save not much
+                data = containers.write(afm.cache, name, data)
+                data = containers.read(afm.cache,name)
+            end
+            if applyruntimefixes and data then
+                applyruntimefixes(filename,data)
+            end
+        end
+        return data
+    else
+        return nil
+    end
+end
+
+local uparser = fonts.mappings.makenameparser()
+
+unify = function(data, filename)
+    local unicodevector = fonts.encodings.agl.unicodes -- loaded runtime in context
+    local unicodes, names = { }, { }
+    local private = constructors.privateoffset
+    local descriptions = data.descriptions
+    for name, blob in next, data.characters do
+        local code = unicodevector[name] -- or characters.name_to_unicode[name]
+        if not code then
+            code = lpegmatch(uparser,name)
+            if not code then
+                code = private
+                private = private + 1
+                report_afm("assigning private slot %U for unknown glyph name %a",code,name)
+            end
+        end
+        local index = blob.index
+        unicodes[name] = code
+        names[name] = index
+        blob.name = name
+        descriptions[code] = {
+            boundingbox = blob.boundingbox,
+            width       = blob.width,
+            kerns       = blob.kerns,
+            index       = index,
+            name        = name,
+        }
+    end
+    for unicode, description in next, descriptions do
+        local kerns = description.kerns
+        if kerns then
+            local krn = { }
+            for name, kern in next, kerns do
+                local unicode = unicodes[name]
+                if unicode then
+                    krn[unicode] = kern
+                else
+                 -- print(unicode,name)
+                end
+            end
+            description.kerns = krn
+        end
+    end
+    data.characters = nil
+    local resources = data.resources
+    local filename = resources.filename or file.removesuffix(file.basename(filename))
+    resources.filename = resolvers.unresolve(filename) -- no shortcut
+    resources.unicodes = unicodes -- name to unicode
+    resources.marks = { } -- todo
+ -- resources.names = names -- name to index
+    resources.private = private
+end
+
+normalize = function(data)
+end
+
+fixnames = function(data)
+    for k, v in next, data.descriptions do
+        local n = v.name
+        local r = overloads[n]
+        if r then
+            local name = r.name
+            if trace_indexing then
+                report_afm("renaming characters %a to %a",n,name)
+            end
+            v.name    = name
+            v.unicode = r.unicode
+        end
+    end
+end
+
+
+--[[ldx--
+<p>These helpers extend the basic table with extra ligatures, texligatures
+and extra kerns. This saves quite some lookups later.</p>
+--ldx]]--
+
+local addthem = function(rawdata,ligatures)
+    if ligatures then
+        local descriptions = rawdata.descriptions
+        local resources    = rawdata.resources
+        local unicodes     = resources.unicodes
+     -- local names        = resources.names
+        for ligname, ligdata in next, ligatures do
+            local one = descriptions[unicodes[ligname]]
+            if one then
+                for _, pair in next, ligdata do
+                    local two, three = unicodes[pair[1]], unicodes[pair[2]]
+                    if two and three then
+                        local ol = one.ligatures
+                        if ol then
+                            if not ol[two] then
+                                ol[two] = three
+                            end
+                        else
+                            one.ligatures = { [two] = three }
+                        end
+                    end
+                end
+            end
+        end
+    end
+end
+
+addligatures    = function(rawdata) addthem(rawdata,afm.helpdata.ligatures   ) end
+addtexligatures = function(rawdata) addthem(rawdata,afm.helpdata.texligatures) end
+
+--[[ldx--
+<p>We keep the extra kerns in separate kerning tables so that we can use
+them selectively.</p>
+--ldx]]--
+
+-- This is rather old code (from the beginning when we had only tfm). If
+-- we unify the afm data (now we have names all over the place) then
+-- we can use shcodes but there will be many more looping then. But we
+-- could get rid of the tables in char-cmp then. Als, in the generic version
+-- we don't use the character database. (Ok, we can have a context specific
+-- variant).
+
+addkerns = function(rawdata) -- using shcodes is not robust here
+    local descriptions = rawdata.descriptions
+    local resources    = rawdata.resources
+    local unicodes     = resources.unicodes
+    local function do_it_left(what)
+        if what then
+            for unicode, description in next, descriptions do
+                local kerns = description.kerns
+                if kerns then
+                    local extrakerns
+                    for complex, simple in next, what do
+                        complex = unicodes[complex]
+                        simple = unicodes[simple]
+                        if complex and simple then
+                            local ks = kerns[simple]
+                            if ks and not kerns[complex] then
+                                if extrakerns then
+                                    extrakerns[complex] = ks
+                                else
+                                    extrakerns = { [complex] = ks }
+                                end
+                            end
+                        end
+                    end
+                    if extrakerns then
+                        description.extrakerns = extrakerns
+                    end
+                end
+            end
+        end
+    end
+    local function do_it_copy(what)
+        if what then
+            for complex, simple in next, what do
+                complex = unicodes[complex]
+                simple = unicodes[simple]
+                if complex and simple then
+                    local complexdescription = descriptions[complex]
+                    if complexdescription then -- optional
+                        local simpledescription = descriptions[complex]
+                        if simpledescription then
+                            local extrakerns
+                            local kerns = simpledescription.kerns
+                            if kerns then
+                                for unicode, kern in next, kerns do
+                                    if extrakerns then
+                                        extrakerns[unicode] = kern
+                                    else
+                                        extrakerns = { [unicode] = kern }
+                                    end
+                                end
+                            end
+                            local extrakerns = simpledescription.extrakerns
+                            if extrakerns then
+                                for unicode, kern in next, extrakerns do
+                                    if extrakerns then
+                                        extrakerns[unicode] = kern
+                                    else
+                                        extrakerns = { [unicode] = kern }
+                                    end
+                                end
+                            end
+                            if extrakerns then
+                                complexdescription.extrakerns = extrakerns
+                            end
+                        end
+                    end
+                end
+            end
+        end
+    end
+    -- add complex with values of simplified when present
+    do_it_left(afm.helpdata.leftkerned)
+    do_it_left(afm.helpdata.bothkerned)
+    -- copy kerns from simple char to complex char unless set
+    do_it_copy(afm.helpdata.bothkerned)
+    do_it_copy(afm.helpdata.rightkerned)
+end
+
+--[[ldx--
+<p>The copying routine looks messy (and is indeed a bit messy).</p>
+--ldx]]--
+
+local function adddimensions(data) -- we need to normalize afm to otf i.e. indexed table instead of name
+    if data then
+        for unicode, description in next, data.descriptions do
+            local bb = description.boundingbox
+            if bb then
+                local ht, dp = bb[4], -bb[2]
+                if ht == 0 or ht < 0 then
+                    -- no need to set it and no negative heights, nil == 0
+                else
+                    description.height = ht
+                end
+                if dp == 0 or dp < 0 then
+                    -- no negative depths and no negative depths, nil == 0
+                else
+                    description.depth  = dp
+                end
+            end
+        end
+    end
+end
+
+local function copytotfm(data)
+    if data and data.descriptions then
+        local metadata     = data.metadata
+        local resources    = data.resources
+        local properties   = derivetable(data.properties)
+        local descriptions = derivetable(data.descriptions)
+        local goodies      = derivetable(data.goodies)
+        local characters   = { }
+        local parameters   = { }
+        local unicodes     = resources.unicodes
+        --
+        for unicode, description in next, data.descriptions do -- use parent table
+            characters[unicode] = { }
+        end
+        --
+        local filename   = constructors.checkedfilename(resources)
+        local fontname   = metadata.fontname or metadata.fullname
+        local fullname   = metadata.fullname or metadata.fontname
+        local endash     = 0x0020 -- space
+        local emdash     = 0x2014
+        local spacer     = "space"
+        local spaceunits = 500
+        --
+        local monospaced  = metadata.isfixedpitch
+        local charwidth   = metadata.charwidth
+        local italicangle = metadata.italicangle
+        local charxheight = metadata.xheight and metadata.xheight > 0 and metadata.xheight
+        properties.monospaced  = monospaced
+        parameters.italicangle = italicangle
+        parameters.charwidth   = charwidth
+        parameters.charxheight = charxheight
+        -- same as otf
+        if properties.monospaced then
+            if descriptions[endash] then
+                spaceunits, spacer = descriptions[endash].width, "space"
+            end
+            if not spaceunits and descriptions[emdash] then
+                spaceunits, spacer = descriptions[emdash].width, "emdash"
+            end
+            if not spaceunits and charwidth then
+                spaceunits, spacer = charwidth, "charwidth"
+            end
+        else
+            if descriptions[endash] then
+                spaceunits, spacer = descriptions[endash].width, "space"
+            end
+            if not spaceunits and charwidth then
+                spaceunits, spacer = charwidth, "charwidth"
+            end
+        end
+        spaceunits = tonumber(spaceunits)
+        if spaceunits < 200 then
+            -- todo: warning
+        end
+        --
+        parameters.slant         = 0
+        parameters.space         = spaceunits
+        parameters.space_stretch = 500
+        parameters.space_shrink  = 333
+        parameters.x_height      = 400
+        parameters.quad          = 1000
+        --
+        if italicangle and italicangle ~= 0 then
+            parameters.italicangle  = italicangle
+            parameters.italicfactor = math.cos(math.rad(90+italicangle))
+            parameters.slant        = - math.tan(italicangle*math.pi/180)
+        end
+        if monospaced then
+            parameters.space_stretch = 0
+            parameters.space_shrink  = 0
+        elseif afm.syncspace then
+            parameters.space_stretch = spaceunits/2
+            parameters.space_shrink  = spaceunits/3
+        end
+        parameters.extra_space = parameters.space_shrink
+        if charxheight then
+            parameters.x_height = charxheight
+        else
+            -- same as otf
+            local x = 0x0078 -- x
+            if x then
+                local x = descriptions[x]
+                if x then
+                    parameters.x_height = x.height
+                end
+            end
+            --
+        end
+        local fd = data.fontdimens
+        if fd and fd[8] and fd[9] and fd[10] then -- math
+            for k,v in next, fd do
+                parameters[k] = v
+            end
+        end
+        --
+        parameters.designsize = (metadata.designsize or 10)*65536
+        parameters.ascender   = abs(metadata.ascender  or 0)
+        parameters.descender  = abs(metadata.descender or 0)
+        parameters.units      = 1000
+        --
+        properties.spacer        = spacer
+        properties.encodingbytes = 2
+        properties.format        = fonts.formats[filename] or "type1"
+        properties.filename      = filename
+        properties.fontname      = fontname
+        properties.fullname      = fullname
+        properties.psname        = fullname
+        properties.name          = filename or fullname or fontname
+        --
+        if next(characters) then
+            return {
+                characters   = characters,
+                descriptions = descriptions,
+                parameters   = parameters,
+                resources    = resources,
+                properties   = properties,
+                goodies      = goodies,
+            }
+        end
+    end
+    return nil
+end
+
+--[[ldx--
+<p>Originally we had features kind of hard coded for <l n='afm'/>
+files but since I expect to support more font formats, I decided
+to treat this fontformat like any other and handle features in a
+more configurable way.</p>
+--ldx]]--
+
+function afm.setfeatures(tfmdata,features)
+    local okay = constructors.initializefeatures("afm",tfmdata,features,trace_features,report_afm)
+    if okay then
+        return constructors.collectprocessors("afm",tfmdata,features,trace_features,report_afm)
+    else
+        return { } -- will become false
+    end
+end
+
+local function addtables(data)
+    local resources  = data.resources
+    local lookuptags = resources.lookuptags
+    local unicodes   = resources.unicodes
+    if not lookuptags then
+        lookuptags = { }
+        resources.lookuptags = lookuptags
+    end
+    setmetatableindex(lookuptags,function(t,k)
+        local v = type(k) == "number" and ("lookup " .. k) or k
+        t[k] = v
+        return v
+    end)
+    if not unicodes then
+        unicodes = { }
+        resources.unicodes = unicodes
+        setmetatableindex(unicodes,function(t,k)
+            setmetatableindex(unicodes,nil)
+            for u, d in next, data.descriptions do
+                local n = d.name
+                if n then
+                    t[n] = u
+                end
+            end
+            return rawget(t,k)
+        end)
+    end
+    constructors.addcoreunicodes(unicodes) -- do we really need this?
+end
+
+local function afmtotfm(specification)
+    local afmname = specification.filename or specification.name
+    if specification.forced == "afm" or specification.format == "afm" then -- move this one up
+        if trace_loading then
+            report_afm("forcing afm format for %a",afmname)
+        end
+    else
+        local tfmname = findbinfile(afmname,"ofm") or ""
+        if tfmname ~= "" then
+            if trace_loading then
+                report_afm("fallback from afm to tfm for %a",afmname)
+            end
+            return -- just that
+        end
+    end
+    if afmname ~= "" then
+        -- weird, isn't this already done then?
+        local features = constructors.checkedfeatures("afm",specification.features.normal)
+        specification.features.normal = features
+        constructors.hashinstance(specification,true) -- also weird here
+        --
+        specification = definers.resolve(specification) -- new, was forgotten
+        local cache_id = specification.hash
+        local tfmdata  = containers.read(constructors.cache, cache_id) -- cache with features applied
+        if not tfmdata then
+            local rawdata = afm.load(afmname)
+            if rawdata and next(rawdata) then
+                addtables(rawdata)
+                adddimensions(rawdata)
+                tfmdata = copytotfm(rawdata)
+                if tfmdata and next(tfmdata) then
+                    local shared = tfmdata.shared
+                    if not shared then
+                        shared         = { }
+                        tfmdata.shared = shared
+                    end
+                    shared.rawdata   = rawdata
+                    shared.features  = features
+                    shared.processes = afm.setfeatures(tfmdata,features)
+                end
+            elseif trace_loading then
+                report_afm("no (valid) afm file found with name %a",afmname)
+            end
+            tfmdata = containers.write(constructors.cache,cache_id,tfmdata)
+        end
+        return tfmdata
+    end
+end
+
+--[[ldx--
+<p>As soon as we could intercept the <l n='tfm'/> reader, I implemented an
+<l n='afm'/> reader. Since traditional <l n='pdftex'/> could use <l n='opentype'/>
+fonts with <l n='afm'/> companions, the following method also could handle
+those cases, but now that we can handle <l n='opentype'/> directly we no longer
+need this features.</p>
+--ldx]]--
+
+local function read_from_afm(specification)
+    local tfmdata = afmtotfm(specification)
+    if tfmdata then
+        tfmdata.properties.name = specification.name
+        tfmdata = constructors.scale(tfmdata, specification)
+        local allfeatures = tfmdata.shared.features or specification.features.normal
+        constructors.applymanipulators("afm",tfmdata,allfeatures,trace_features,report_afm)
+        fonts.loggers.register(tfmdata,'afm',specification)
+    end
+    return tfmdata
+end
+
+--[[ldx--
+<p>Here comes the implementation of a few features. We only implement
+those that make sense for this format.</p>
+--ldx]]--
+
+local function prepareligatures(tfmdata,ligatures,value)
+    if value then
+        local descriptions = tfmdata.descriptions
+        local hasligatures = false
+        for unicode, character in next, tfmdata.characters do
+            local description = descriptions[unicode]
+            local dligatures = description.ligatures
+            if dligatures then
+                local cligatures = character.ligatures
+                if not cligatures then
+                    cligatures = { }
+                    character.ligatures = cligatures
+                end
+                for unicode, ligature in next, dligatures do
+                    cligatures[unicode] = {
+                        char = ligature,
+                        type = 0
+                    }
+                end
+                hasligatures = true
+            end
+        end
+        tfmdata.properties.hasligatures = hasligatures
+    end
+end
+
+local function preparekerns(tfmdata,kerns,value)
+    if value then
+        local rawdata      = tfmdata.shared.rawdata
+        local resources    = rawdata.resources
+        local unicodes     = resources.unicodes
+        local descriptions = tfmdata.descriptions
+        local haskerns     = false
+        for u, chr in next, tfmdata.characters do
+            local d = descriptions[u]
+            local newkerns = d[kerns]
+            if newkerns then
+                local kerns = chr.kerns
+                if not kerns then
+                    kerns = { }
+                    chr.kerns = kerns
+                end
+                for k,v in next, newkerns do
+                    local uk = unicodes[k]
+                    if uk then
+                        kerns[uk] = v
+                    end
+                end
+                haskerns = true
+            end
+        end
+        tfmdata.properties.haskerns = haskerns
+    end
+end
+
+local list = {
+ -- [0x0022] = 0x201D,
+    [0x0027] = 0x2019,
+ -- [0x0060] = 0x2018,
+}
+
+local function texreplacements(tfmdata,value)
+    local descriptions = tfmdata.descriptions
+    local characters   = tfmdata.characters
+    for k, v in next, list do
+        characters  [k] = characters  [v] -- we forget about kerns
+        descriptions[k] = descriptions[v] -- we forget about kerns
+    end
+end
+
+local function ligatures   (tfmdata,value) prepareligatures(tfmdata,'ligatures',   value) end
+local function texligatures(tfmdata,value) prepareligatures(tfmdata,'texligatures',value) end
+local function kerns       (tfmdata,value) preparekerns    (tfmdata,'kerns',       value) end
+local function extrakerns  (tfmdata,value) preparekerns    (tfmdata,'extrakerns',  value) end
+
+registerafmfeature {
+    name         = "liga",
+    description  = "traditional ligatures",
+    initializers = {
+        base = ligatures,
+        node = ligatures,
+    }
+}
+
+registerafmfeature {
+    name         = "kern",
+    description  = "intercharacter kerning",
+    initializers = {
+        base = kerns,
+        node = kerns,
+    }
+}
+
+registerafmfeature {
+    name         = "extrakerns",
+    description  = "additional intercharacter kerning",
+    initializers = {
+        base = extrakerns,
+        node = extrakerns,
+    }
+}
+
+registerafmfeature {
+    name         = 'tlig',
+    description  = 'tex ligatures',
+    initializers = {
+        base = texligatures,
+        node = texligatures,
+    }
+}
+
+registerafmfeature {
+    name         = 'trep',
+    description  = 'tex replacements',
+    initializers = {
+        base = texreplacements,
+        node = texreplacements,
+    }
+}
+
+-- readers
+
+local check_tfm   = readers.check_tfm
+
+fonts.formats.afm = "type1"
+fonts.formats.pfb = "type1"
+
+local function check_afm(specification,fullname)
+    local foundname = findbinfile(fullname, 'afm') or "" -- just to be sure
+    if foundname == "" then
+        foundname = fonts.names.getfilename(fullname,"afm") or ""
+    end
+    if foundname == "" and afm.autoprefixed then
+        local encoding, shortname = match(fullname,"^(.-)%-(.*)$") -- context: encoding-name.*
+        if encoding and shortname and fonts.encodings.known[encoding] then
+            shortname = findbinfile(shortname,'afm') or "" -- just to be sure
+            if shortname ~= "" then
+                foundname = shortname
+                if trace_defining then
+                    report_afm("stripping encoding prefix from filename %a",afmname)
+                end
+            end
+        end
+    end
+    if foundname ~= "" then
+        specification.filename = foundname
+        specification.format   = "afm"
+        return read_from_afm(specification)
+    end
+end
+
+function readers.afm(specification,method)
+    local fullname, tfmdata = specification.filename or "", nil
+    if fullname == "" then
+        local forced = specification.forced or ""
+        if forced ~= "" then
+            tfmdata = check_afm(specification,specification.name .. "." .. forced)
+        end
+        if not tfmdata then
+            method = method or definers.method or "afm or tfm"
+            if method == "tfm" then
+                tfmdata = check_tfm(specification,specification.name)
+            elseif method == "afm" then
+                tfmdata = check_afm(specification,specification.name)
+            elseif method == "tfm or afm" then
+                tfmdata = check_tfm(specification,specification.name) or check_afm(specification,specification.name)
+            else -- method == "afm or tfm" or method == "" then
+                tfmdata = check_afm(specification,specification.name) or check_tfm(specification,specification.name)
+            end
+        end
+    else
+        tfmdata = check_afm(specification,fullname)
+    end
+    return tfmdata
+end
+
+function readers.pfb(specification,method) -- only called when forced
+    local original = specification.specification
+    if trace_defining then
+        report_afm("using afm reader for %a",original)
+    end
+    specification.specification = gsub(original,"%.pfb",".afm")
+    specification.forced = "afm"
+    return readers.afm(specification,method)
+end