summaryrefslogtreecommitdiff
path: root/macros/luatex/generic/luaotfload/fontloader-font-one.lua
blob: 25efc2a04673647b841f9b4a319d110a93395aa4 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
if not modules then modules = { } end modules ['font-one'] = {
    version   = 1.001,
    optimize  = true,
    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"
}

-- 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 TFM to AFM
-- to OTF.
--
-- The following code still has traces of intermediate font support where we handles
-- font encodings. Eventually font encoding went away but we kept some code around
-- in other modules.
--
-- This version implements a node mode approach so that users can also more easily
-- add features.

local fonts, logs, trackers, containers, resolvers = fonts, logs, trackers, containers, resolvers

local next, type, tonumber, rawget = next, type, tonumber, rawget
local match, gsub = string.match, string.gsub
local abs = math.abs
local P, S, R, Cmt, C, Ct, Cs, Carg = lpeg.P, lpeg.S, lpeg.R, lpeg.Cmt, lpeg.C, lpeg.Ct, lpeg.Cs, lpeg.Carg
local lpegmatch, patterns = lpeg.match, lpeg.patterns
local sortedhash = table.sortedhash

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 derivetable         = table.derive

local findbinfile         = resolvers.findbinfile

local privateoffset       = fonts.constructors and fonts.constructors.privateoffset or 0xF0000 -- 0x10FFFF

local definers            = fonts.definers
local readers             = fonts.readers
local constructors        = fonts.constructors

local afm                 = constructors.handlers.afm
local pfb                 = constructors.handlers.pfb
local otf                 = fonts.handlers.otf

local otfreaders          = otf.readers
local otfenhancers        = otf.enhancers

local afmfeatures         = constructors.features.afm
local registerafmfeature  = afmfeatures.register

local afmenhancers        = constructors.enhancers.afm
local registerafmenhancer = afmenhancers.register

afm.version               = 1.513 -- incrementing this number one up will force a re-cache
afm.cache                 = containers.define("fonts", "one", 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

local overloads           = fonts.mappings.overloads

local applyruntimefixes   = fonts.treatments and fonts.treatments.applyfixes

-- 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.
--
-- We still keep the loading two phased: first we load the data in a traditional
-- fashion and later we transform it to sequences. Then we apply some methods also
-- used in opentype fonts (like tlig).

function afm.load(filename)
    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 = attr and attr.size or 0
        local time = attr and 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 = 0
        local pfbtime = 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 = afm.readers.loadfont(filename,pfbname)
            if data then
                afmenhancers.apply(data,filename)
             -- otfreaders.addunicodetable(data) -- only when not done yet
                fonts.mappings.addtounicode(data,filename)
                otfreaders.stripredundant(data)
             -- otfreaders.extend(data)
                otfreaders.pack(data)
                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
        end
        if data then
         -- constructors.addcoreunicodes(unicodes)
            otfreaders.unpack(data)
            otfreaders.expand(data) -- inline tables
            otfreaders.addunicodetable(data) -- only when not done yet
            otfenhancers.apply(data,filename,data)
            if applyruntimefixes then
                applyruntimefixes(filename,data)
            end
        end
        return data
    end
end

-- we run a more advanced analyzer later on anyway

local uparser = fonts.mappings.makenameparser() -- each time

local function enhance_unify_names(data, filename)
    local unicodevector = fonts.encodings.agl.unicodes -- loaded runtime in context
    local unicodes      = { }
    local names         = { }
    local private       = data.private or privateoffset
    local descriptions  = data.descriptions
    for name, blob in sortedhash(data.characters) do -- sorting is nicer for privates
        local code = unicodevector[name] -- or characters.name_to_unicode[name]
        if not code then
            code = lpegmatch(uparser,name)
            if type(code) ~= "number" 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
    data.private    = private
    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
end

local everywhere = { ["*"] = { ["*"] = true } } -- or: { ["*"] = { "*" } }
local noflags    = { false, false, false, false }

local function enhance_normalize_features(data)
    local ligatures  = setmetatableindex("table")
    local kerns      = setmetatableindex("table")
    local extrakerns = setmetatableindex("table")
    for u, c in next, data.descriptions do
        local l = c.ligatures
        local k = c.kerns
        local e = c.extrakerns
        if l then
            ligatures[u] = l
            for u, v in next, l do
                l[u] = { ligature = v }
            end
            c.ligatures = nil
        end
        if k then
            kerns[u] = k
            for u, v in next, k do
                k[u] = v -- { v, 0 }
            end
            c.kerns = nil
        end
        if e then
            extrakerns[u] = e
            for u, v in next, e do
                e[u] = v -- { v, 0 }
            end
            c.extrakerns = nil
        end
    end
    local features = {
        gpos = { },
        gsub = { },
    }
    local sequences = {
        -- only filled ones
    }
    if next(ligatures) then
        features.gsub.liga = everywhere
        data.properties.hasligatures = true
        sequences[#sequences+1] = {
            features = {
                liga = everywhere,
            },
            flags    = noflags,
            name     = "s_s_0",
            nofsteps = 1,
            order    = { "liga" },
            type     = "gsub_ligature",
            steps    = {
                {
                    coverage = ligatures,
                },
            },
        }
    end
    if next(kerns) then
        features.gpos.kern = everywhere
        data.properties.haskerns = true
        sequences[#sequences+1] = {
            features = {
                kern = everywhere,
            },
            flags    = noflags,
            name     = "p_s_0",
            nofsteps = 1,
            order    = { "kern" },
            type     = "gpos_pair",
            steps    = {
                {
                    format   = "kern",
                    coverage = kerns,
                },
            },
        }
    end
    if next(extrakerns) then
        features.gpos.extrakerns = everywhere
        data.properties.haskerns = true
        sequences[#sequences+1] = {
            features = {
                extrakerns = everywhere,
            },
            flags    = noflags,
            name     = "p_s_1",
            nofsteps = 1,
            order    = { "extrakerns" },
            type     = "gpos_pair",
            steps    = {
                {
                    format   = "kern",
                    coverage = extrakerns,
                },
            },
        }
    end
    -- todo: compress kerns
    data.resources.features  = features
    data.resources.sequences = sequences
end

local function enhance_fix_names(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

-- These helpers extend the basic table with extra ligatures, texligatures and extra
-- kerns. This saves quite some lookups later.

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   = unicodes[pair[1]]
                    local three = 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

local function enhance_add_ligatures(rawdata)
    addthem(rawdata,afm.helpdata.ligatures)
end

-- We keep the extra kerns in separate kerning tables so that we can use them
-- selectively.
--
-- 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).

local function enhance_add_extra_kerns(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

-- The copying routine looks messy (and is indeed a bit messy).

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 =  bb[4]
                local dp = -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     = 0x2013
        local emdash     = 0x2014
        local space      = 0x0020 -- space
        local spacer     = "space"
        local spaceunits = 500
        --
        local monospaced  = metadata.monospaced
        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
        -- nearly the same as otf, catches
        local d_endash = descriptions[endash]
        local d_emdash = descriptions[emdash]
        local d_space  = descriptions[space]
        if not d_space or d_space == 0 then
            d_space = d_endash
        end
        if d_space then
            spaceunits, spacer = d_space.width or 0, "space"
        end
        if properties.monospaced then
            if spaceunits == 0 and d_emdash then
                spaceunits, spacer = d_emdash.width or 0, "emdash"
            end
        else
            if spaceunits == 0 and d_endash then
                spaceunits, spacer = d_emdash.width or 0, "endash"
            end
        end
        if spaceunits == 0 and charwidth then
            spaceunits, spacer = charwidth or 0, "charwidth"
        end
        if spaceunits == 0 then
            spaceunits = tonumber(spaceunits) or 500
        end
        if spaceunits == 0 then
            spaceunits = 500
        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
        --
        if metadata.sup then
            local dummy    = { 0, 0, 0 }
            parameters[ 1] = metadata.designsize        or 0
            parameters[ 2] = metadata.checksum          or 0
            parameters[ 3],
            parameters[ 4],
            parameters[ 5] = unpack(metadata.space      or dummy)
            parameters[ 6] =        metadata.quad       or 0
            parameters[ 7] =        metadata.extraspace or 0
            parameters[ 8],
            parameters[ 9],
            parameters[10] = unpack(metadata.num        or dummy)
            parameters[11],
            parameters[12] = unpack(metadata.denom      or dummy)
            parameters[13],
            parameters[14],
            parameters[15] = unpack(metadata.sup        or dummy)
            parameters[16],
            parameters[17] = unpack(metadata.sub        or dummy)
            parameters[18] =        metadata.supdrop    or 0
            parameters[19] =        metadata.subdrop    or 0
            parameters[20],
            parameters[21] = unpack(metadata.delim      or dummy)
            parameters[22] =        metadata.axisheight or 0
        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.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
        properties.private  = properties.private or data.private or privateoffset
        --
if not CONTEXTLMTXMODE or CONTEXTLMTXMODE == 0 then
        properties.encodingbytes = 2
end
        --
        if next(characters) then
            return {
                characters   = characters,
                descriptions = descriptions,
                parameters   = parameters,
                resources    = resources,
                properties   = properties,
                goodies      = goodies,
            }
        end
    end
    return nil
end

-- Originally we had features kind of hard coded for 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.

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.dynamics  = { }
                    tfmdata.changed  = { }
                    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

-- As soon as we could intercept the TFM reader, I implemented an AFM reader. Since
-- traditional pdfTeX could use OpenType fonts with AFM companions, the following
-- method also could handle those cases, but now that we can handle OpenType
-- directly we no longer need this features.

local function read_from_afm(specification)
    local tfmdata = afmtotfm(specification)
    if tfmdata then
        tfmdata.properties.name = specification.name
        tfmdata.properties.id   = specification.id
        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

-- We have the usual two modes and related features initializers and processors.

registerafmfeature {
    name         = "mode",
    description  = "mode",
    initializers = {
        base = otf.modeinitializer,
        node = otf.modeinitializer,
    }
}

registerafmfeature {
    name         = "features",
    description  = "features",
    default      = true,
    initializers = {
        node     = otf.nodemodeinitializer,
        base     = otf.basemodeinitializer,
    },
    processors   = {
        node     = otf.featuresprocessor,
    }
}

-- readers

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 fullname and 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 = specification.filename or ""
    local tfmdata  = nil
    if fullname == "" then
        local forced = specification.forced or ""
        if forced ~= "" then
            tfmdata = check_afm(specification,specification.name .. "." .. forced)
        end
        if not tfmdata then
            local check_tfm = readers.check_tfm
            method = (check_tfm and (method or definers.method or "afm or tfm")) or "afm"
            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.forced = "afm"
    local function swap(name)
        local value = specification[swap]
        if value then
            specification[swap] = gsub("%.pfb",".afm",1)
        end
    end
    swap("filename")
    swap("fullname")
    swap("forcedname")
    swap("specification")
    return readers.afm(specification,method)
end

-- now we register them

registerafmenhancer("unify names",          enhance_unify_names)
registerafmenhancer("add ligatures",        enhance_add_ligatures)
registerafmenhancer("add extra kerns",      enhance_add_extra_kerns)
registerafmenhancer("normalize features",   enhance_normalize_features)
registerafmenhancer("check extra features", otfenhancers.enhance)
registerafmenhancer("fix names",            enhance_fix_names)