summaryrefslogtreecommitdiff
path: root/Master/texmf-dist/tex/context/base/font-inj.lua
blob: 332e92033fdc12e29e3a0c58c750620305e73385 (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
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
if not modules then modules = { } end modules ['font-inj'] = {
    version   = 1.001,
    comment   = "companion to font-lib.mkiv",
    author    = "Hans Hagen, PRAGMA-ADE, Hasselt NL",
    copyright = "PRAGMA ADE / ConTeXt Development Team",
    license   = "see context related readme files",
}

-- This property based variant is not faster but looks nicer than the attribute one. We
-- need to use rawget (which is apbout 4 times slower than a direct access but we cannot
-- get/set that one for our purpose!

if not nodes.properties then return end

local next, rawget = next, rawget
local utfchar = utf.char
local fastcopy = table.fastcopy

local trace_injections = false  trackers.register("fonts.injections", function(v) trace_injections = v end)

local report_injections = logs.reporter("fonts","injections")

local attributes, nodes, node = attributes, nodes, node

fonts                    = fonts
local fontdata           = fonts.hashes.identifiers

nodes.injections         = nodes.injections or { }
local injections         = nodes.injections

local nodecodes          = nodes.nodecodes
local glyph_code         = nodecodes.glyph
local disc_code          = nodecodes.disc
local kern_code          = nodecodes.kern

local nuts               = nodes.nuts
local nodepool           = nuts.pool

local newkern            = nodepool.kern

local tonode             = nuts.tonode
local tonut              = nuts.tonut

local getfield           = nuts.getfield
local setfield           = nuts.setfield
local getnext            = nuts.getnext
local getprev            = nuts.getprev
local getid              = nuts.getid
local getfont            = nuts.getfont
local getsubtype         = nuts.getsubtype
local getchar            = nuts.getchar

local traverse_id        = nuts.traverse_id
local insert_node_before = nuts.insert_before
local insert_node_after  = nuts.insert_after
local find_tail          = nuts.tail

local properties         = nodes.properties.data

function injections.installnewkern(nk)
    newkern = nk or newkern
end

local nofregisteredkerns    = 0
local nofregisteredpairs    = 0
local nofregisteredmarks    = 0
local nofregisteredcursives = 0
----- markanchors           = { } -- one base can have more marks
local keepregisteredcounts  = false

function injections.keepcounts()
    keepregisteredcounts = true
end

function injections.resetcounts()
    nofregisteredkerns    = 0
    nofregisteredpairs    = 0
    nofregisteredmarks    = 0
    nofregisteredcursives = 0
    keepregisteredcounts  = false
end

-- We need to make sure that a possible metatable will not kick in
-- unexpectedly.

function injections.reset(n)
    local p = rawget(properties,n)
    if p and rawget(p,"injections") then
        p.injections = nil
    end
end

function injections.copy(target,source)
    local sp = rawget(properties,source)
    if sp then
        local tp = rawget(properties,target)
        local si = rawget(sp,"injections")
        if si then
            si = fastcopy(si)
            if tp then
                tp.injections = si
            else
                propertydata[target] = {
                    injections = si,
                }
            end
        else
            if tp then
                tp.injections = nil
            end
        end
    end
end

function injections.setligaindex(n,index)
    local p = rawget(properties,n)
    if p then
        local i = rawget(p,"injections")
        if i then
            i.ligaindex = index
        else
            p.injections = {
                ligaindex = index
            }
        end
    else
        properties[n] = {
            injections = {
                ligaindex = index
            }
        }
    end
end

function injections.getligaindex(n,default)
    local p = rawget(properties,n)
    if p then
        local i = rawget(p,"injections")
        if i then
            return i.ligaindex or default
        end
    end
    return default
end

function injections.setcursive(start,nxt,factor,rlmode,exit,entry,tfmstart,tfmnext) -- hm: nuts or nodes
    local dx =  factor*(exit[1]-entry[1])
    local dy = -factor*(exit[2]-entry[2])
    local ws, wn = tfmstart.width, tfmnext.width
    nofregisteredcursives = nofregisteredcursives + 1
    if rlmode < 0 then
        dx = -(dx + wn)
    else
        dx = dx - ws
    end
    --
    local p = rawget(properties,start)
    if p then
        local i = rawget(p,"injections")
        if i then
            i.cursiveanchor = true
        else
            p.injections = {
                cursiveanchor = true,
            }
        end
    else
        properties[start] = {
            injections = {
                cursiveanchor = true,
            },
        }
    end
    local p = rawget(properties,nxt)
    if p then
        local i = rawget(p,"injections")
        if i then
            i.cursivex = dx
            i.cursivey = dy
        else
            p.injections = {
                cursivex = dx,
                cursivey = dy,
            }
        end
    else
        properties[nxt] = {
            injections = {
                cursivex = dx,
                cursivey = dy,
            },
        }
    end
    return dx, dy, nofregisteredcursives
end

function injections.setpair(current,factor,rlmode,r2lflag,spec,injection) -- r2lflag & tfmchr not used
    local x, y, w, h = factor*spec[1], factor*spec[2], factor*spec[3], factor*spec[4]
    if x ~= 0 or w ~= 0 or y ~= 0 or h ~= 0 then -- okay?
        local yoffset   = y - h
        local leftkern  = x      -- both kerns are set in a pair kern compared
        local rightkern = w - x  -- to normal kerns where we set only leftkern
        if leftkern ~= 0 or rightkern ~= 0 or yoffset ~= 0 then
            nofregisteredpairs = nofregisteredpairs + 1
            if rlmode and rlmode < 0 then
                leftkern, rightkern = rightkern, leftkern
            end
            local p = rawget(properties,current)
            if p then
                local i = rawget(p,"injections")
                if i then
                    if leftkern ~= 0 then
                        i.leftkern  = (i.leftkern  or 0) + leftkern
                    end
                    if rightkern ~= 0 then
                        i.rightkern = (i.rightkern or 0) + rightkern
                    end
                    if yoffset ~= 0 then
                        i.yoffset = (i.yoffset or 0) + yoffset
                    end
                elseif leftkern ~= 0 or rightkern ~= 0 then
                    p.injections = {
                        leftkern  = leftkern,
                        rightkern = rightkern,
                        yoffset   = yoffset,
                    }
                else
                    p.injections = {
                        yoffset = yoffset,
                    }
                end
            elseif leftkern ~= 0 or rightkern ~= 0 then
                properties[current] = {
                    injections = {
                        leftkern  = leftkern,
                        rightkern = rightkern,
                        yoffset   = yoffset,
                    },
                }
            else
                properties[current] = {
                    injections = {
                        yoffset = yoffset,
                    },
                }
            end
            return x, y, w, h, nofregisteredpairs
         end
    end
    return x, y, w, h -- no bound
end

-- this needs checking for rl < 0 but it is unlikely that a r2l script
-- uses kernclasses between glyphs so we're probably safe (KE has a
-- problematic font where marks interfere with rl < 0 in the previous
-- case)

function injections.setkern(current,factor,rlmode,x,injection)
    local dx = factor * x
    if dx ~= 0 then
        nofregisteredkerns = nofregisteredkerns + 1
        local p = rawget(properties,current)
        if not injection then
            injection = "injections"
        end
        if p then
            local i = rawget(p,injection)
            if i then
                i.leftkern = dx + (i.leftkern or 0)
            else
                p[injection] = {
                    leftkern = dx,
                }
            end
        else
            properties[current] = {
                [injection] = {
                    leftkern = dx,
                },
            }
        end
        return dx, nofregisteredkerns
    else
        return 0, 0
    end
end

function injections.setmark(start,base,factor,rlmode,ba,ma,tfmbase) -- ba=baseanchor, ma=markanchor
    local dx, dy = factor*(ba[1]-ma[1]), factor*(ba[2]-ma[2])
    nofregisteredmarks = nofregisteredmarks + 1
 -- markanchors[nofregisteredmarks] = base
    if rlmode >= 0 then
        dx = tfmbase.width - dx -- see later commented ox
    end
    local p = rawget(properties,start)
    if p then
        local i = rawget(p,"injections")
        if i then
            i.markx        = dx
            i.marky        = dy
            i.markdir      = rlmode or 0
            i.markbase     = nofregisteredmarks
            i.markbasenode = base
        else
            p.injections = {
                markx        = dx,
                marky        = dy,
                markdir      = rlmode or 0,
                markbase     = nofregisteredmarks,
                markbasenode = base,
            }
        end
    else
        properties[start] = {
            injections = {
                markx        = dx,
                marky        = dy,
                markdir      = rlmode or 0,
                markbase     = nofregisteredmarks,
                markbasenode = base,
            },
        }
    end
    return dx, dy, nofregisteredmarks
end

local function dir(n)
    return (n and n<0 and "r-to-l") or (n and n>0 and "l-to-r") or "unset"
end

local function showchar(n,nested)
    local char = getchar(n)
    report_injections("%wfont %s, char %U, glyph %c",nested and 2 or 0,getfont(n),char,char)
end

local function show(n,what,nested,symbol)
    if n then
        local p = rawget(properties,n)
        if p then
            local i = rawget(p,what)
            if i then
                local leftkern  = i.leftkern  or 0
                local rightkern = i.rightkern or 0
                local yoffset   = i.yoffset   or 0
                local markx     = i.markx     or 0
                local marky     = i.marky     or 0
                local markdir   = i.markdir   or 0
                local markbase  = i.markbase  or 0 -- will be markbasenode
                local cursivex  = i.cursivex  or 0
                local cursivey  = i.cursivey  or 0
                local ligaindex = i.ligaindex or 0
                local margin    = nested and 4 or 2
                --
                if rightkern ~= 0 or yoffset ~= 0 then
                    report_injections("%w%s pair: lx %p, rx %p, dy %p",margin,symbol,leftkern,rightkern,yoffset)
                elseif leftkern ~= 0 then
                    report_injections("%w%s kern: dx %p",margin,symbol,leftkern)
                end
                if markx ~= 0 or marky ~= 0 or markbase ~= 0 then
                    report_injections("%w%s mark: dx %p, dy %p, dir %s, base %s",margin,symbol,markx,marky,markdir,markbase ~= 0 and "yes" or "no")
                end
                if cursivex ~= 0 or cursivey ~= 0 then
                    report_injections("%w%s curs: dx %p, dy %p",margin,symbol,cursivex,cursivey)
                end
                if ligaindex ~= 0 then
                    report_injections("%w%s liga: index %i",margin,symbol,ligaindex)
                end
            end
        end
    end
end

local function showsub(n,what,where)
    report_injections("begin subrun: %s",where)
    for n in traverse_id(glyph_code,n) do
        showchar(n,where)
        show(n,what,where," ")
    end
    report_injections("end subrun")
end

local function trace(head,where)
    report_injections("begin run %s: %s kerns, %s pairs, %s marks and %s cursives registered",
        where or "",nofregisteredkerns,nofregisteredpairs,nofregisteredmarks,nofregisteredcursives)
    local n = head
    while n do
        local id = getid(n)
        if id == glyph_code then
            showchar(n)
            show(n,"injections",false," ")
            show(n,"preinjections",false,"<")
            show(n,"postinjections",false,">")
            show(n,"replaceinjections",false,"=")
        elseif id == disc_code then
            local pre     = getfield(n,"pre")
            local post    = getfield(n,"post")
            local replace = getfield(n,"replace")
            if pre then
                showsub(pre,"preinjections","pre")
            end
            if post then
                showsub(post,"postinjections","post")
            end
            if replace then
                showsub(replace,"replaceinjections","replace")
            end
        end
        n = getnext(n)
    end
    report_injections("end run")
end

local function show_result(head)
    local current  = head
    local skipping = false
    while current do
        local id = getid(current)
        if id == glyph_code then
            report_injections("char: %C, width %p, xoffset %p, yoffset %p",
                getchar(current),getfield(current,"width"),getfield(current,"xoffset"),getfield(current,"yoffset"))
            skipping = false
        elseif id == kern_code then
            report_injections("kern: %p",getfield(current,"kern"))
            skipping = false
        elseif not skipping then
            report_injections()
            skipping = true
        end
        current = getnext(current)
    end
end

-- we could also check for marks here but maybe not all are registered (needs checking)

local function collect_glyphs_1(head)
    local glyphs, nofglyphs = { }, 0
    local marks, nofmarks = { }, 0
    local nf, tm = nil, nil
    for n in traverse_id(glyph_code,head) do -- only needed for relevant fonts
        if getsubtype(n) < 256 then
            local f = getfont(n)
            if f ~= nf then
                nf = f
                tm = fontdata[nf].resources.marks -- other hash in ctx
            end
            if tm and tm[getchar(n)] then
                nofmarks = nofmarks + 1
                marks[nofmarks] = n
            else
                nofglyphs = nofglyphs + 1
                glyphs[nofglyphs] = n
            end
            -- yoffsets can influence curs steps
            local p = rawget(properties,n)
            if p then
                local i = rawget(p,"injections")
                if i then
                    local yoffset = i.yoffset
                    if yoffset and yoffset ~= 0 then
                        setfield(n,"yoffset",yoffset)
                    end
                end
            end
        end
    end
    return glyphs, nofglyphs, marks, nofmarks
end

local function collect_glyphs_2(head)
    local glyphs, nofglyphs = { }, 0
    local marks, nofmarks = { }, 0
    local nf, tm = nil, nil
    for n in traverse_id(glyph_code,head) do
        if getsubtype(n) < 256 then
            local f = getfont(n)
            if f ~= nf then
                nf = f
                tm = fontdata[nf].resources.marks -- other hash in ctx
            end
            if tm and tm[getchar(n)] then
                nofmarks = nofmarks + 1
                marks[nofmarks] = n
            else
                nofglyphs = nofglyphs + 1
                glyphs[nofglyphs] = n
            end
        end
    end
    return glyphs, nofglyphs, marks, nofmarks
end

local function inject_marks(marks,nofmarks)
    for i=1,nofmarks do
        local n = marks[i]
        local pn = rawget(properties,n)
        if pn then
            pn = rawget(pn,"injections")
            if pn then
                local p = pn.markbasenode
                if p then
                    local px = getfield(p,"xoffset")
                    local ox = 0
                    local rightkern = nil
                    local pp = rawget(properties,p)
                    if pp then
                        pp = rawget(pp,"injections")
                        if pp then
                            rightkern = pp.rightkern
                        end
                    end
                    if rightkern then -- x and w ~= 0
                        if pn.markdir < 0 then
                            -- kern(w-x) glyph(p) kern(x) mark(n)
                            ox = px - pn.markx - rightkern
                         -- report_injections("r2l case 1: %p",ox)
                        else
                            -- kern(x) glyph(p) kern(w-x) mark(n)
                         -- ox = px - getfield(p,"width") + pn.markx - pp.leftkern
                            local leftkern = pp.leftkern
                            if leftkern then
                                ox = px - pn.markx
                            else
                                ox = px - pn.markx - leftkern
                            end
-- report_injections("l2r case 1: %p",ox)
                        end
                    else
                        -- we need to deal with fonts that have marks with width
                     -- if pn.markdir < 0 then
                     --     ox = px - pn.markx
                     --  -- report_injections("r2l case 3: %p",ox)
                     -- else
                     --  -- ox = px - getfield(p,"width") + pn.markx
                            ox = px - pn.markx
                         -- report_injections("l2r case 3: %p",ox)
                     -- end
                        local wn = getfield(n,"width") -- in arial marks have widths
                        if wn ~= 0 then
                            -- bad: we should center
                         -- insert_node_before(head,n,newkern(-wn/2))
                         -- insert_node_after(head,n,newkern(-wn/2))
                            pn.leftkern  = -wn/2
                            pn.rightkern = -wn/2
                         -- wx[n] = { 0, -wn/2, 0, -wn }
                        end
                        -- so far
                    end
                    setfield(n,"xoffset",ox)
                    --
                    local py = getfield(p,"yoffset")
                    local oy = 0
                    if marks[p] then
                        oy = py + pn.marky
                    else
                        oy = getfield(n,"yoffset") + py + pn.marky
                    end
                    setfield(n,"yoffset",oy)
                else
                    -- normally this can't happen (only when in trace mode which is a special case anyway)
                 -- report_injections("missing mark anchor %i",pn.markbase or 0)
                end
            end
        end
    end
end

local function inject_cursives(glyphs,nofglyphs)
    local cursiveanchor, lastanchor = nil, nil
    local minc, maxc, last = 0, 0, nil
    for i=1,nofglyphs do
        local n = glyphs[i]
        local pn = rawget(properties,n)
        if pn then
            pn = rawget(pn,"injections")
        end
        if pn then
            local cursivex = pn.cursivex
            if cursivex then
                if cursiveanchor then
                    if cursivex ~= 0 then
                        pn.leftkern = (pn.leftkern or 0) + cursivex
                    end
                    if lastanchor then
                        if maxc == 0 then
                            minc = lastanchor
                        end
                        maxc = lastanchor
                        properties[cursiveanchor].cursivedy = pn.cursivey
                    end
                    last = n
                else
                    maxc = 0
                end
            elseif maxc > 0 then
                local ny = getfield(n,"yoffset")
                for i=maxc,minc,-1 do
                    local ti = glyphs[i]
                    ny = ny + properties[ti].cursivedy
                    setfield(ti,"yoffset",ny) -- why not add ?
                end
                maxc = 0
            end
            if pn.cursiveanchor then
                cursiveanchor = n
                lastanchor = i
            else
                cursiveanchor = nil
                lastanchor = nil
                if maxc > 0 then
                    local ny = getfield(n,"yoffset")
                    for i=maxc,minc,-1 do
                        local ti = glyphs[i]
                        ny = ny + properties[ti].cursivedy
                        setfield(ti,"yoffset",ny) -- why not add ?
                    end
                    maxc = 0
                end
            end
        elseif maxc > 0 then
            local ny = getfield(n,"yoffset")
            for i=maxc,minc,-1 do
                local ti = glyphs[i]
                ny = ny + properties[ti].cursivedy
                setfield(ti,"yoffset",getfield(ti,"yoffset") + ny) -- ?
            end
            maxc = 0
            cursiveanchor = nil
            lastanchor = nil
        end
     -- if maxc > 0 and not cursiveanchor then
     --     local ny = getfield(n,"yoffset")
     --     for i=maxc,minc,-1 do
     --         local ti = glyphs[i]
     --         ny = ny + properties[ti].cursivedy
     --         setfield(ti,"yoffset",ny) -- why not add ?
     --     end
     --     maxc = 0
     -- end
    end
    if last and maxc > 0 then
        local ny = getfield(last,"yoffset")
        for i=maxc,minc,-1 do
            local ti = glyphs[i]
            ny = ny + properties[ti].cursivedy
            setfield(ti,"yoffset",ny) -- why not add ?
        end
    end
end

local function inject_kerns(head,list,length)
 -- todo: pre/post/replace
    for i=1,length do
        local n  = list[i]
        local pn = rawget(properties,n)
        if pn then
            local i = rawget(pn,"injections")
            if i then
                local leftkern = i.leftkern
                if leftkern and leftkern ~= 0 then
                    insert_node_before(head,n,newkern(leftkern)) -- type 0/2
                end
                local rightkern = i.rightkern
                if rightkern and rightkern ~= 0 then
                    insert_node_after(head,n,newkern(rightkern)) -- type 0/2
                end
            end
        end
    end
end

local function inject_everything(head,where)
    head = tonut(head)
    if trace_injections then
        trace(head,"everything")
    end
    local glyphs, nofglyphs, marks, nofmarks
    if nofregisteredpairs > 0 then
        glyphs, nofglyphs, marks, nofmarks = collect_glyphs_1(head)
    else
        glyphs, nofglyphs, marks, nofmarks = collect_glyphs_2(head)
    end
    if nofglyphs > 0 then
        if nofregisteredcursives > 0 then
            inject_cursives(glyphs,nofglyphs)
        end
        if nofregisteredmarks > 0 then -- and nofmarks > 0
            inject_marks(marks,nofmarks)
        end
        inject_kerns(head,glyphs,nofglyphs)
    end
    if nofmarks > 0 then
        inject_kerns(head,marks,nofmarks)
	end
    if keepregisteredcounts then
        keepregisteredcounts  = false
    else
        nofregisteredkerns    = 0
        nofregisteredpairs    = 0
        nofregisteredmarks    = 0
        nofregisteredcursives = 0
    end
    return tonode(head), true
end

local function inject_kerns_only(head,where)
    head = tonut(head)
    if trace_injections then
        trace(head,"kerns")
    end
    local n = head
    local p = nil
    while n do
        local id = getid(n)
        if id == glyph_code then
            if getsubtype(n) < 256 then
                local pn = rawget(properties,n)
                if pn then
                    if p then
                        local d = getfield(p,"post")
                        if d then
                            local i = rawget(pn,"postinjections")
                            if i then
                                local leftkern = i.leftkern
                                if leftkern and leftkern ~= 0 then
                                    local t = find_tail(d)
                                    insert_node_after(d,t,newkern(leftkern))
                                end
                            end
                        end
                        local d = getfield(p,"replace")
                        if d then
                            local i = rawget(pn,"replaceinjections")
                            if i then
                                local leftkern = i.leftkern
                                if leftkern and leftkern ~= 0 then
                                    local t = find_tail(d)
                                    insert_node_after(d,t,newkern(leftkern))
                                end
                            end
                        else
                            local i = rawget(pn,"injections")
                            if i then
                                local leftkern = i.leftkern
                                if leftkern and leftkern ~= 0 then
                                    setfield(p,"replace",newkern(leftkern))
                                end
                            end
                        end
                    else
                        local i = rawget(pn,"injections")
                        if i then
                            local leftkern = i.leftkern
                            if leftkern and leftkern ~= 0 then
                                head = insert_node_before(head,n,newkern(leftkern))
                            end
                        end
                    end
                end
            else
                break
            end
            p = nil
        elseif id == disc_code then
            local d = getfield(n,"pre")
            if d then
                local h = d
                for n in traverse_id(glyph_code,d) do
                    if getsubtype(n) < 256 then
                        local pn = rawget(properties,n)
                        if pn then
                            local i = rawget(pn,"preinjections")
                            if i then
                                local leftkern = i.leftkern
                                if leftkern and leftkern ~= 0 then
                                    h = insert_node_before(h,n,newkern(leftkern))
                                end
                            end
                        end
                    else
                        break
                    end
                end
                if h ~= d then
                    setfield(n,"pre",h)
                end
            end
            local d = getfield(n,"post")
            if d then
                local h = d
                for n in traverse_id(glyph_code,d) do
                    if getsubtype(n) < 256 then
                        local pn = rawget(properties,n)
                        if pn then
                            local i = rawget(pn,"postinjections")
                            if i then
                                local leftkern = i.leftkern
                                if leftkern and leftkern ~= 0 then
                                    h = insert_node_before(h,n,newkern(leftkern))
                                end
                            end
                        end
                    else
                        break
                    end
                end
                if h ~= d then
                    setfield(n,"post",h)
                end
            end
            local d = getfield(n,"replace")
            if d then
                local h = d
                for n in traverse_id(glyph_code,d) do
                    if getsubtype(n) < 256 then
                        local pn = rawget(properties,n) -- why can it be empty { }
                        if pn then
                            local i = rawget(pn,"replaceinjections")
                            if i then
                                local leftkern = i.leftkern
                                if leftkern and leftkern ~= 0 then
                                    h = insert_node_before(h,n,newkern(leftkern))
                                end
                            end
                        end
                    else
                        break
                    end
                end
                if h ~= d then
                    setfield(n,"replace",h)
                end
            end
            p = n
        else
            p = nil
        end
        n = getnext(n)
    end
    --
    if keepregisteredcounts then
        keepregisteredcounts = false
    else
        nofregisteredkerns   = 0
    end
    return tonode(head), true
end

local function inject_pairs_only(head,where)
    head = tonut(head)
    if trace_injections then
        trace(head,"pairs")
    end
    --
    local n = head
    local p = nil
    while n do
        local id = getid(n)
        if id == glyph_code then
            if getsubtype(n) < 256 then
                local pn = rawget(properties,n)
                if pn then
                    if p then
                        local d = getfield(p,"post")
                        if d then
                            local i = rawget(pn,"postinjections")
                            if i then
                                local leftkern = i.leftkern
                                if leftkern and leftkern ~= 0 then
                                    local t = find_tail(d)
                                    insert_node_after(d,t,newkern(leftkern))
                                end
                             -- local rightkern = i.rightkern
                             -- if rightkern and rightkern ~= 0 then
                             --     insert_node_after(head,n,newkern(rightkern))
                             --     n = getnext(n) -- to be checked
                             -- end
                            end
                        end
                        local d = getfield(p,"replace")
                        if d then
                            local i = rawget(pn,"replaceinjections")
                            if i then
                                local leftkern = i.leftkern
                                if leftkern and leftkern ~= 0 then
                                    local t = find_tail(d)
                                    insert_node_after(d,t,newkern(leftkern))
                                end
                             -- local rightkern = i.rightkern
                             -- if rightkern and rightkern ~= 0 then
                             --     insert_node_after(head,n,newkern(rightkern))
                             --     n = getnext(n) -- to be checked
                             -- end
                            end
                        else
                            local i = rawget(pn,"injections")
                            if i then
                                local leftkern = i.leftkern
                                if leftkern and leftkern ~= 0 then
                                    setfield(p,"replace",newkern(leftkern))
                                end
                             -- local rightkern = i.rightkern
                             -- if rightkern and rightkern ~= 0 then
                             --     insert_node_after(head,n,newkern(rightkern))
                             --     n = getnext(n) -- to be checked
                             -- end
                            end
                        end
                    else
                        -- this is the most common case
                        local i = rawget(pn,"injections")
                        if i then
                            local yoffset = i.yoffset
                            if yoffset and yoffset ~= 0 then
                                setfield(n,"yoffset",yoffset)
                            end
                            local leftkern = i.leftkern
                            if leftkern and leftkern ~= 0 then
                                insert_node_before(head,n,newkern(leftkern))
                            end
                            local rightkern = i.rightkern
                            if rightkern and rightkern ~= 0 then
                                insert_node_after(head,n,newkern(rightkern))
                                n = getnext(n) -- to be checked
                            end
                        end
                    end
                end
            else
                break
            end
            p = nil
        elseif id == disc_code then
            local d = getfield(n,"pre")
            if d then
                local h = d
                for n in traverse_id(glyph_code,d) do
                    if getsubtype(n) < 256 then
                        local p = rawget(properties,n)
                        if p then
                            local i = rawget(p,"preinjections")
                            if i then
                                local yoffset = i.yoffset
                                if yoffset and yoffset ~= 0 then
                                    setfield(n,"yoffset",yoffset)
                                end
                                local leftkern = i.leftkern
                                if leftkern ~= 0 then
                                    h = insert_node_before(h,n,newkern(leftkern))
                                end
                                local rightkern = i.rightkern
                                if rightkern and rightkern ~= 0 then
                                    insert_node_after(head,n,newkern(rightkern))
                                    n = getnext(n) -- to be checked
                                end
                            end
                        end
                    else
                        break
                    end
                end
                if h ~= d then
                    setfield(n,"pre",h)
                end
            end
            local d = getfield(n,"post")
            if d then
                local h = d
                for n in traverse_id(glyph_code,d) do
                    if getsubtype(n) < 256 then
                        local p = rawget(properties,n)
                        if p then
                            local i = rawget(p,"postinjections")
                            if i then
                                local yoffset = i.yoffset
                                if yoffset and yoffset ~= 0 then
                                    setfield(n,"yoffset",yoffset)
                                end
                                local leftkern = i.leftkern
                                if leftkern and leftkern ~= 0 then
                                    h = insert_node_before(h,n,newkern(leftkern))
                                end
                                local rightkern = i.rightkern
                                if rightkern and rightkern ~= 0 then
                                    insert_node_after(head,n,newkern(rightkern))
                                    n = getnext(n) -- to be checked
                                end
                            end
                        end
                    else
                        break
                    end
                end
                if h ~= d then
                    setfield(n,"post",h)
                end
            end
            local d = getfield(n,"replace")
            if d then
                local h = d
                for n in traverse_id(glyph_code,d) do
                    if getsubtype(n) < 256 then
                        local p = rawget(properties,n)
                        if p then
                            local i = rawget(p,"replaceinjections")
                            if i then
                                local yoffset = i.yoffset
                                if yoffset and yoffset ~= 0 then
                                    setfield(n,"yoffset",yoffset)
                                end
                                local leftkern = i.leftkern
                                if leftkern and leftkern ~= 0 then
                                    h = insert_node_before(h,n,newkern(leftkern))
                                end
                                local rightkern = i.rightkern
                                if rightkern and rightkern ~= 0 then
                                    insert_node_after(head,n,newkern(rightkern))
                                    n = getnext(n) -- to be checked
                                end
                            end
                        end
                    else
                        break
                    end
                end
                if h ~= d then
                    setfield(n,"replace",h)
                end
            end
            p = n
        else
            p = nil
        end
        n = getnext(n)
    end
    --
    if keepregisteredcounts then
        keepregisteredcounts = false
    else
        nofregisteredpairs = 0
        nofregisteredkerns = 0
    end
    return tonode(head), true
end

function injections.handler(head,where) -- optimize for n=1 ?
    if nofregisteredmarks > 0 or nofregisteredcursives > 0 then
        return inject_everything(head,where)
    elseif nofregisteredpairs > 0 then
        return inject_pairs_only(head,where)
    elseif nofregisteredkerns > 0 then
        return inject_kerns_only(head,where)
    else
        return head, false
    end
end