1if not modules then modules = { } end modules [ ' font-otc ' ] = {
2 version = 1 . 001 ,
3 comment = " companion to font-ini.mkiv " ,
4 author = " Hans Hagen, PRAGMA-ADE, Hasselt NL " ,
5 copyright = " PRAGMA ADE / ConTeXt Development Team " ,
6 license = " see context related readme files "
7}
8
9local insert , sortedkeys , sortedhash , tohash = table . insert , table . sortedkeys , table . sortedhash , table . tohash
10local type , next , tonumber = type , next , tonumber
11local lpegmatch = lpeg . match
12local utfbyte , utflen = utf . byte , utf . len
13local sortedhash = table . sortedhash
14
15
16
17local trace_loading = false trackers . register ( " otf.loading " , function ( v ) trace_loading = v end )
18local report_otf = logs . reporter ( " fonts " , " otf loading " )
19
20local fonts = fonts
21local otf = fonts . handlers . otf
22local registerotffeature = otf . features . register
23local setmetatableindex = table . setmetatableindex
24
25local fonthelpers = fonts . helpers
26local checkmerge = fonthelpers . checkmerge
27local checkflags = fonthelpers . checkflags
28local checksteps = fonthelpers . checksteps
29
30local normalized = {
31 substitution = " substitution " ,
32 single = " substitution " ,
33 ligature = " ligature " ,
34 alternate = " alternate " ,
35 multiple = " multiple " ,
36 kern = " kern " ,
37 pair = " pair " ,
38 single = " single " ,
39 chainsubstitution = " chainsubstitution " ,
40 chainposition = " chainposition " ,
41}
42
43local types = {
44 substitution = " gsub_single " ,
45 ligature = " gsub_ligature " ,
46 alternate = " gsub_alternate " ,
47 multiple = " gsub_multiple " ,
48 kern = " gpos_pair " ,
49 pair = " gpos_pair " ,
50 single = " gpos_single " ,
51 chainsubstitution = " gsub_contextchain " ,
52 chainposition = " gpos_contextchain " ,
53}
54
55local names = {
56 gsub_single = " gsub " ,
57 gsub_multiple = " gsub " ,
58 gsub_alternate = " gsub " ,
59 gsub_ligature = " gsub " ,
60 gsub_context = " gsub " ,
61 gsub_contextchain = " gsub " ,
62 gsub_reversecontextchain = " gsub " ,
63 gpos_single = " gpos " ,
64 gpos_pair = " gpos " ,
65 gpos_cursive = " gpos " ,
66 gpos_mark2base = " gpos " ,
67 gpos_mark2ligature = " gpos " ,
68 gpos_mark2mark = " gpos " ,
69 gpos_context = " gpos " ,
70 gpos_contextchain = " gpos " ,
71}
72
73setmetatableindex ( types , function ( t , k ) t [ k ] = k return k end )
74
75local everywhere = { [ " * " ] = { [ " * " ] = true } }
76local noflags = { false , false , false , false }
77
78
79
80local function getrange ( sequences , category )
81 local count = # sequences
82 local first = nil
83 local last = nil
84 for i = 1 , count do
85 local t = sequences [ i ] . type
86 if t and names [ t ] = = category then
87 if not first then
88 first = i
89 end
90 last = i
91 end
92 end
93 return first or 1 , last or count
94end
95
96local function validspecification ( specification , name )
97 local dataset = specification . dataset
98 if dataset then
99
100 elseif specification [ 1 ] then
101 dataset = specification
102 specification = { dataset = dataset }
103 else
104 dataset = { { data = specification . data } }
105 specification . data = nil
106 specification . coverage = dataset
107 specification . dataset = dataset
108 end
109 local first = dataset [ 1 ]
110 if first then
111 first = first . data
112 end
113 if not first then
114 report_otf ( " invalid feature specification, no dataset " )
115 return
116 end
117 if type ( name ) ~ = " string " then
118 name = specification . name or first . name
119 end
120 if type ( name ) ~ = " string " then
121 report_otf ( " invalid feature specification, no name " )
122 return
123 end
124 local n = # dataset
125 if n > 0 then
126 for i = 1 , n do
127 setmetatableindex ( dataset [ i ] , specification )
128 end
129 return specification , name
130 end
131end
132
133local function addfeature ( data , feature , specifications )
134
135
136
137
138 if not specifications then
139 report_otf ( " missing specification " )
140 return
141 end
142
143 local descriptions = data . descriptions
144 local resources = data . resources
145 local features = resources . features
146 local sequences = resources . sequences
147
148 if not features or not sequences then
149 report_otf ( " missing specification " )
150 return
151 end
152
153 local alreadydone = resources . alreadydone
154 if not alreadydone then
155 alreadydone = { }
156 resources . alreadydone = alreadydone
157 end
158 if alreadydone [ specifications ] then
159 return
160 else
161 alreadydone [ specifications ] = true
162 end
163
164
165
166 local fontfeatures = resources . features or everywhere
167 local unicodes = resources . unicodes
168 local splitter = lpeg . splitter ( " " , unicodes )
169 local done = 0
170 local skip = 0
171 local aglunicodes = false
172 local privateslot = fonthelpers . privateslot
173
174 local specifications = validspecification ( specifications , feature )
175 if not specifications then
176
177 return
178 end
179
180 local p = lpeg . P ( " P " )
181 * ( lpeg . patterns . hexdigit ^ 1 / function ( s ) return tonumber ( s , 16 ) end )
182 * lpeg . P ( -1 )
183
184 local function tounicode ( code )
185 if not code then
186 return
187 end
188 if type ( code ) = = " number " then
189 return code
190 end
191 local u = unicodes [ code ]
192 if u then
193
194 return u
195 end
196 if utflen ( code ) = = 1 then
197 u = utfbyte ( code )
198 if u then
199 return u
200 end
201 end
202 if privateslot then
203 u = privateslot ( code )
204 if u then
205
206 return u
207 end
208 end
209 local u = lpegmatch ( p , code )
210 if u then
211
212 return u
213 end
214 if not aglunicodes then
215 aglunicodes = fonts . encodings . agl . unicodes
216 end
217 local u = aglunicodes [ code ]
218 if u then
219
220 return u
221 end
222 end
223
224 local coverup = otf . coverup
225 local coveractions = coverup . actions
226 local stepkey = coverup . stepkey
227 local register = coverup . register
228
229 local function prepare_substitution ( list , featuretype , nocheck )
230 local coverage = { }
231 local cover = coveractions [ featuretype ]
232 for code , replacement in next , list do
233 local unicode = tounicode ( code )
234 local description = descriptions [ unicode ]
235 if not nocheck and not description then
236
237 skip = skip + 1
238 else
239 if type ( replacement ) = = " table " then
240 replacement = replacement [ 1 ]
241 end
242 replacement = tounicode ( replacement )
243 if replacement and ( nocheck or descriptions [ replacement ] ) then
244 cover ( coverage , unicode , replacement )
245 done = done + 1
246 else
247 skip = skip + 1
248 end
249 end
250 end
251 return coverage
252 end
253
254 local function prepare_alternate ( list , featuretype , nocheck )
255 local coverage = { }
256 local cover = coveractions [ featuretype ]
257 for code , replacement in next , list do
258 local unicode = tounicode ( code )
259 local description = descriptions [ unicode ]
260 if not nocheck and not description then
261 skip = skip + 1
262 elseif type ( replacement ) = = " table " then
263 local r = { }
264 for i = 1 , # replacement do
265 local u = tounicode ( replacement [ i ] )
266 r [ i ] = ( nocheck or descriptions [ u ] ) and u or unicode
267 end
268 cover ( coverage , unicode , r )
269 done = done + 1
270 else
271 local u = tounicode ( replacement )
272 if u then
273 cover ( coverage , unicode , { u } )
274 done = done + 1
275 else
276 skip = skip + 1
277 end
278 end
279 end
280 return coverage
281 end
282
283 local function prepare_multiple ( list , featuretype , nocheck )
284 local coverage = { }
285 local cover = coveractions [ featuretype ]
286 for code , replacement in next , list do
287 local unicode = tounicode ( code )
288 local description = descriptions [ unicode ]
289 if not nocheck and not description then
290 skip = skip + 1
291 elseif type ( replacement ) = = " table " then
292 local r = { }
293 local n = 0
294 for i = 1 , # replacement do
295 local u = tounicode ( replacement [ i ] )
296 if nocheck or descriptions [ u ] then
297 n = n + 1
298 r [ n ] = u
299 end
300 end
301 if n > 0 then
302 cover ( coverage , unicode , r )
303 done = done + 1
304 else
305 skip = skip + 1
306 end
307 else
308 local u = tounicode ( replacement )
309 if u then
310 cover ( coverage , unicode , { u } )
311 done = done + 1
312 else
313 skip = skip + 1
314 end
315 end
316 end
317 return coverage
318 end
319
320 local function prepare_ligature ( list , featuretype , nocheck )
321 local coverage = { }
322 local cover = coveractions [ featuretype ]
323 for code , ligature in next , list do
324 local unicode = tounicode ( code )
325 local description = descriptions [ unicode ]
326 if not nocheck and not description then
327 skip = skip + 1
328 else
329 if type ( ligature ) = = " string " then
330 ligature = { lpegmatch ( splitter , ligature ) }
331 end
332 local present = true
333 for i = 1 , # ligature do
334 local l = ligature [ i ]
335 local u = tounicode ( l )
336 if nocheck or descriptions [ u ] then
337 ligature [ i ] = u
338 else
339 present = false
340 break
341 end
342 end
343 if present then
344 cover ( coverage , unicode , ligature )
345 done = done + 1
346 else
347 skip = skip + 1
348 end
349 end
350 end
351 return coverage
352 end
353
354 local function resetspacekerns ( )
355
356
357
358 data . properties . hasspacekerns = true
359 data . resources . spacekerns = nil
360 end
361
362 local function prepare_kern ( list , featuretype )
363 local coverage = { }
364 local cover = coveractions [ featuretype ]
365 local isspace = false
366 for code , replacement in next , list do
367 local unicode = tounicode ( code )
368 local description = descriptions [ unicode ]
369 if description and type ( replacement ) = = " table " then
370 local r = { }
371 for k , v in next , replacement do
372 local u = tounicode ( k )
373 if u then
374 r [ u ] = v
375 if u = = 32 then
376 isspace = true
377 end
378 end
379 end
380 if next ( r ) then
381 cover ( coverage , unicode , r )
382 done = done + 1
383 if unicode = = 32 then
384 isspace = true
385 end
386 else
387 skip = skip + 1
388 end
389 else
390 skip = skip + 1
391 end
392 end
393 if isspace then
394 resetspacekerns ( )
395 end
396 return coverage
397 end
398
399 local function prepare_pair ( list , featuretype )
400 local coverage = { }
401 local cover = coveractions [ featuretype ]
402 if cover then
403 for code , replacement in next , list do
404 local unicode = tounicode ( code )
405 local description = descriptions [ unicode ]
406 if description and type ( replacement ) = = " table " then
407 local r = { }
408 for k , v in next , replacement do
409 local u = tounicode ( k )
410 if u then
411 r [ u ] = v
412 if u = = 32 then
413 isspace = true
414 end
415 end
416 end
417 if next ( r ) then
418 cover ( coverage , unicode , r )
419 done = done + 1
420 if unicode = = 32 then
421 isspace = true
422 end
423 else
424 skip = skip + 1
425 end
426 else
427 skip = skip + 1
428 end
429 end
430 if isspace then
431 resetspacekerns ( )
432 end
433 else
434 report_otf ( " unknown cover type %a " , featuretype )
435 end
436 return coverage
437 end
438
439 local prepare_single = prepare_pair
440
441 local function hassteps ( lookups )
442 if lookups then
443 for i = 1 , # lookups do
444 local l = lookups [ i ]
445 if l then
446 for j = 1 , # l do
447 local l = l [ j ]
448 if l then
449 local n = l . nofsteps
450 if not n then
451
452 return true
453 elseif n > 0 then
454 return true
455 end
456 end
457 end
458 end
459 end
460 end
461 return false
462 end
463
464 local function prepare_chain ( list , featuretype , sublookups , nocheck )
465
466 local rules = list . rules
467 local coverage = { }
468 if rules then
469 local rulehash = { }
470 local rulesize = 0
471 local lookuptype = types [ featuretype ]
472 for nofrules = 1 , # rules do
473 local rule = rules [ nofrules ]
474 local current = rule . current
475 local before = rule . before
476 local after = rule . after
477 local replacements = rule . replacements or false
478 local sequence = { }
479 local nofsequences = 0
480 if before then
481 for n = 1 , # before do
482 nofsequences = nofsequences + 1
483 sequence [ nofsequences ] = before [ n ]
484 end
485 end
486 local start = nofsequences + 1
487 for n = 1 , # current do
488 nofsequences = nofsequences + 1
489 sequence [ nofsequences ] = current [ n ]
490 end
491 local stop = nofsequences
492 if after then
493 for n = 1 , # after do
494 nofsequences = nofsequences + 1
495 sequence [ nofsequences ] = after [ n ]
496 end
497 end
498 local lookups = rule . lookups or false
499 local subtype = nil
500 if lookups and sublookups then
501 local l = { }
502 for k , v in sortedhash ( lookups ) do
503 local t = type ( v )
504 if t = = " table " then
505
506 for i = 1 , # v do
507 local vi = v [ i ]
508 if type ( vi ) ~ = " table " then
509 v [ i ] = { vi }
510 end
511 end
512 l [ k ] = v
513 elseif t = = " number " then
514 local lookup = sublookups [ v ]
515 if lookup then
516 l [ k ] = { lookup }
517 if not subtype then
518 subtype = lookup . type
519 end
520 elseif v = = 0 then
521 l [ k ] = { { type = " gsub_remove " , nosteps = true } }
522 else
523 l [ k ] = false
524 end
525 else
526 l [ k ] = false
527 end
528 end
529 if nocheck then
530
531 rule . lookups = l
532 end
533 lookups = l
534 end
535 if nofsequences > 0 then
536
537 if hassteps ( lookups ) then
538 local hashed = { }
539 for i = 1 , nofsequences do
540 local t = { }
541 local s = sequence [ i ]
542 for i = 1 , # s do
543 local u = tounicode ( s [ i ] )
544 if u then
545 t [ u ] = true
546 end
547 end
548 hashed [ i ] = t
549 end
550 sequence = hashed
551 rulesize = rulesize + 1
552 rulehash [ rulesize ] = {
553 nofrules ,
554 lookuptype ,
555 sequence ,
556 start ,
557 stop ,
558 lookups ,
559 replacements ,
560 subtype ,
561 }
562 for unic in sortedhash ( sequence [ start ] ) do
563 local cu = coverage [ unic ]
564 if not cu then
565 coverage [ unic ] = rulehash
566 end
567 end
568 sequence . n = nofsequences
569 else
570
571 end
572 end
573 end
574 rulehash . n = rulesize
575 end
576 return coverage
577 end
578
579 local dataset = specifications . dataset
580
581 local function report ( name , category , position , first , last , sequences )
582 report_otf ( " injecting name %a of category %a at position %i in [%i,%i] of [%i,%i] " ,
583 name , category , position , first , last , 1 , # sequences )
584 end
585
586 local function inject ( specification , sequences , sequence , first , last , category , name )
587 local position = specification . position or false
588 if not position then
589 position = specification . prepend
590 if position = = true then
591 if trace_loading then
592 report ( name , category , first , first , last , sequences )
593 end
594 insert ( sequences , first , sequence )
595 return
596 end
597 end
598 if not position then
599 position = specification . append
600 if position = = true then
601 if trace_loading then
602 report ( name , category , last + 1 , first , last , sequences )
603 end
604 insert ( sequences , last + 1 , sequence )
605 return
606 end
607 end
608 local kind = type ( position )
609 if kind = = " string " then
610 local index = false
611 for i = first , last do
612 local s = sequences [ i ]
613 local f = s . features
614 if f then
615 for k in sortedhash ( f ) do
616 if k = = position then
617 index = i
618 break
619 end
620 end
621 if index then
622 break
623 end
624 end
625 end
626 if index then
627 position = index
628 else
629 position = last + 1
630 end
631 elseif kind = = " number " then
632 if position < 0 then
633 position = last - position + 1
634 end
635 if position > last then
636 position = last + 1
637 elseif position < first then
638 position = first
639 end
640 else
641 position = last + 1
642 end
643 if trace_loading then
644 report ( name , category , position , first , last , sequences )
645 end
646 insert ( sequences , position , sequence )
647 end
648
649 for s = 1 , # dataset do
650 local specification = dataset [ s ]
651 local valid = specification . valid
652 local feature = specification . name or feature
653 if not feature or feature = = " " then
654 report_otf ( " no valid name given for extra feature " )
655 elseif not valid or valid ( data , specification , feature ) then
656 local initialize = specification . initialize
657 if initialize then
658
659 specification . initialize = initialize ( specification , data ) and initialize or nil
660 end
661 local askedfeatures = specification . features or everywhere
662 local askedsteps = specification . steps or specification . subtables or { specification . data } or { }
663 local featuretype = specification . type or " substitution "
664 local featureaction = false
665 local featureflags = specification . flags or noflags
666 local nocheck = specification . nocheck
667 local mapping = specification . mapping
668 local featureorder = specification . order or { feature }
669 local featurechain = ( featuretype = = " chainsubstitution " or featuretype = = " chainposition " ) and 1 or 0
670 local nofsteps = 0
671 local steps = { }
672 local sublookups = specification . lookups
673 local category = nil
674 local steptype = nil
675 local sequence = nil
676
677 if fonts . handlers . otf . handlers [ featuretype ] then
678 featureaction = true
679 else
680 featuretype = normalized [ specification . type or " substitution " ] or " substitution "
681 end
682
683 checkflags ( specification , resources )
684
685 for k , v in next , askedfeatures do
686 if v [ 1 ] then
687 askedfeatures [ k ] = tohash ( v )
688 end
689 end
690
691 if featureflags [ 1 ] then featureflags [ 1 ] = " mark " end
692 if featureflags [ 2 ] then featureflags [ 2 ] = " ligature " end
693 if featureflags [ 3 ] then featureflags [ 3 ] = " base " end
694
695 if featureaction then
696
697 category = " gsub "
698 sequence = {
699 features = { [ feature ] = askedfeatures } ,
700 flags = featureflags ,
701 name = feature ,
702 order = featureorder ,
703 type = featuretype ,
704
705 nofsteps = 0 ,
706 }
707
708 else
709
710 if sublookups then
711 local s = { }
712 for i = 1 , # sublookups do
713 local specification = sublookups [ i ]
714 local askedsteps = specification . steps or specification . subtables or { specification . data } or { }
715 local featuretype = normalized [ specification . type or " substitution " ] or " substitution "
716 local featureflags = specification . flags or noflags
717 local nofsteps = 0
718 local steps = { }
719 for i = 1 , # askedsteps do
720 local list = askedsteps [ i ]
721 local coverage = nil
722 local format = nil
723 if featuretype = = " substitution " then
724 coverage = prepare_substitution ( list , featuretype , nocheck )
725 elseif featuretype = = " ligature " then
726 coverage = prepare_ligature ( list , featuretype , nocheck )
727 elseif featuretype = = " alternate " then
728 coverage = prepare_alternate ( list , featuretype , nocheck )
729 elseif featuretype = = " multiple " then
730 coverage = prepare_multiple ( list , featuretype , nocheck )
731 elseif featuretype = = " kern " or featuretype = = " move " then
732 format = featuretype
733 coverage = prepare_kern ( list , featuretype )
734 elseif featuretype = = " pair " then
735 format = " pair "
736 coverage = prepare_pair ( list , featuretype )
737 elseif featuretype = = " single " then
738 format = " single "
739 coverage = prepare_single ( list , featuretype )
740 end
741 if coverage and next ( coverage ) then
742 nofsteps = nofsteps + 1
743 steps [ nofsteps ] = register ( coverage , featuretype , format , feature , nofsteps , descriptions , resources )
744 end
745 end
746
747 checkmerge ( specification )
748 checksteps ( specification )
749
750 s [ i ] = {
751 [ stepkey ] = steps ,
752 nofsteps = nofsteps ,
753 flags = featureflags ,
754 type = types [ featuretype ] ,
755 }
756 end
757 sublookups = s
758 end
759
760 for i = 1 , # askedsteps do
761 local list = askedsteps [ i ]
762 local coverage = nil
763 local format = nil
764 if featuretype = = " substitution " then
765
766 category = " gsub "
767 coverage = ( mapping and list ) or prepare_substitution ( list , featuretype , nocheck )
768 elseif featuretype = = " ligature " then
769 category = " gsub "
770 coverage = prepare_ligature ( list , featuretype , nocheck )
771 elseif featuretype = = " alternate " then
772 category = " gsub "
773 coverage = prepare_alternate ( list , featuretype , nocheck )
774 elseif featuretype = = " multiple " then
775 category = " gsub "
776 coverage = prepare_multiple ( list , featuretype , nocheck )
777 elseif featuretype = = " kern " or featuretype = = " move " then
778 category = " gpos "
779 format = featuretype
780 coverage = prepare_kern ( list , featuretype )
781 elseif featuretype = = " pair " then
782 category = " gpos "
783 format = " pair "
784 coverage = prepare_pair ( list , featuretype )
785 elseif featuretype = = " single " then
786 category = " gpos "
787 format = " single "
788 coverage = prepare_single ( list , featuretype )
789 elseif featuretype = = " chainsubstitution " then
790 category = " gsub "
791 coverage = prepare_chain ( list , featuretype , sublookups , nocheck )
792 elseif featuretype = = " chainposition " then
793 category = " gpos "
794 coverage = prepare_chain ( list , featuretype , sublookups , nocheck )
795 else
796 report_otf ( " not registering feature %a, unknown category " , feature )
797 return
798 end
799 if coverage and next ( coverage ) then
800 nofsteps = nofsteps + 1
801 steps [ nofsteps ] = register ( coverage , featuretype , format , feature , nofsteps , descriptions , resources )
802 end
803 end
804
805 if nofsteps > 0 then
806 sequence = {
807 chain = featurechain ,
808 features = { [ feature ] = askedfeatures } ,
809 flags = featureflags ,
810 name = feature ,
811 order = featureorder ,
812 [ stepkey ] = steps ,
813 nofsteps = nofsteps ,
814 type = types [ featuretype ] ,
815 }
816 end
817 end
818
819 if sequence then
820
821 checkflags ( sequence , resources )
822 checkmerge ( sequence )
823 checksteps ( sequence )
824
825 local first , last = getrange ( sequences , category )
826 inject ( specification , sequences , sequence , first , last , category , feature )
827
828 local features = fontfeatures [ category ]
829 if not features then
830 features = { }
831 fontfeatures [ category ] = features
832 end
833 local k = features [ feature ]
834 if not k then
835 k = { }
836 features [ feature ] = k
837 end
838
839 for script , languages in next , askedfeatures do
840 local kk = k [ script ]
841 if not kk then
842 kk = { }
843 k [ script ] = kk
844 end
845 for language , value in next , languages do
846 kk [ language ] = value
847 end
848 end
849 end
850
851 end
852 end
853 if trace_loading then
854 report_otf ( " registering feature %a, affected glyphs %a, skipped glyphs %a " , feature , done , skip )
855 end
856
857end
858
859otf . enhancers . addfeature = addfeature
860
861local extrafeatures = { }
862local knownfeatures = { }
863
864function otf . addfeature ( name , specification )
865 if type ( name ) = = " table " then
866 specification = name
867 end
868 if type ( specification ) ~ = " table " then
869 report_otf ( " invalid feature specification, no valid table " )
870 return
871 end
872 specification , name = validspecification ( specification , name )
873 if name and specification then
874 local slot = knownfeatures [ name ]
875 if not slot then
876
877 slot = # extrafeatures + 1
878 knownfeatures [ name ] = slot
879 elseif specification . overload = = false then
880
881 slot = # extrafeatures + 1
882 knownfeatures [ name ] = slot
883 else
884
885 end
886 specification . name = name
887 extrafeatures [ slot ] = specification
888
889 end
890end
891
892
893
894
895
896local function enhance ( data , filename , raw )
897 for slot = 1 , # extrafeatures do
898 local specification = extrafeatures [ slot ]
899 addfeature ( data , specification . name , specification )
900 end
901end
902
903otf . enhancers . enhance = enhance
904
905otf . enhancers . register ( " check extra features " , enhance )
906
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