summaryrefslogtreecommitdiff
path: root/Master/texmf-dist/tex/context/base/mkiv/font-cff.lua
blob: a799a67f52ec9aa840dee77148c4b98ee3070dd3 (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
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
1248
1249
1250
1251
1252
1253
1254
1255
1256
1257
1258
1259
1260
1261
1262
1263
1264
1265
1266
1267
1268
1269
1270
1271
1272
1273
1274
1275
1276
1277
1278
1279
1280
1281
1282
1283
1284
1285
1286
1287
1288
1289
1290
1291
1292
1293
1294
1295
1296
1297
1298
1299
1300
1301
1302
1303
1304
1305
1306
1307
1308
1309
1310
1311
1312
1313
1314
1315
1316
1317
1318
1319
1320
1321
1322
1323
1324
1325
1326
1327
1328
1329
1330
1331
1332
1333
1334
1335
1336
1337
1338
1339
1340
1341
1342
1343
1344
1345
1346
1347
1348
1349
1350
1351
1352
1353
1354
1355
1356
1357
1358
1359
1360
1361
1362
1363
1364
1365
1366
1367
1368
1369
1370
1371
1372
1373
1374
1375
1376
1377
1378
1379
1380
1381
1382
1383
1384
1385
1386
1387
1388
1389
1390
1391
1392
1393
1394
1395
1396
1397
1398
1399
1400
1401
1402
1403
1404
1405
1406
1407
1408
1409
1410
1411
1412
1413
1414
1415
1416
1417
1418
1419
1420
1421
1422
1423
1424
1425
1426
1427
1428
1429
1430
1431
1432
1433
1434
1435
1436
1437
1438
1439
1440
1441
1442
1443
1444
1445
1446
1447
1448
1449
1450
1451
1452
1453
1454
1455
1456
1457
1458
1459
1460
1461
1462
1463
1464
1465
1466
1467
1468
1469
1470
1471
1472
1473
1474
1475
1476
1477
1478
1479
1480
1481
1482
1483
1484
1485
1486
1487
1488
1489
1490
1491
1492
1493
1494
1495
1496
1497
1498
1499
1500
1501
1502
1503
1504
1505
1506
1507
1508
1509
1510
1511
1512
1513
1514
1515
1516
1517
1518
1519
1520
1521
1522
1523
1524
1525
1526
1527
1528
1529
1530
1531
1532
1533
1534
1535
1536
1537
1538
1539
1540
1541
1542
1543
1544
1545
1546
1547
1548
1549
1550
1551
1552
1553
1554
1555
1556
1557
1558
1559
1560
1561
1562
1563
1564
1565
1566
1567
1568
1569
1570
1571
1572
1573
1574
1575
1576
1577
1578
1579
1580
1581
1582
1583
1584
1585
1586
1587
1588
1589
1590
1591
1592
1593
1594
1595
1596
1597
1598
1599
1600
1601
1602
1603
1604
1605
1606
1607
1608
1609
1610
1611
1612
1613
1614
1615
1616
1617
1618
1619
1620
1621
1622
1623
1624
1625
1626
1627
1628
1629
1630
1631
1632
1633
1634
1635
1636
1637
1638
1639
1640
1641
1642
1643
1644
1645
1646
1647
1648
1649
1650
1651
1652
1653
1654
1655
1656
1657
1658
1659
1660
1661
1662
1663
1664
1665
1666
1667
1668
1669
1670
1671
1672
1673
1674
1675
1676
1677
1678
1679
1680
1681
1682
1683
1684
1685
1686
1687
1688
1689
1690
1691
1692
1693
1694
1695
1696
1697
1698
1699
1700
1701
1702
1703
1704
1705
1706
1707
1708
1709
1710
1711
1712
1713
1714
1715
1716
1717
1718
1719
1720
1721
1722
1723
1724
1725
1726
1727
1728
1729
1730
1731
1732
1733
1734
1735
1736
1737
1738
1739
1740
1741
1742
1743
1744
1745
1746
1747
1748
1749
1750
1751
1752
1753
1754
1755
1756
1757
1758
1759
1760
1761
1762
1763
1764
1765
1766
1767
1768
1769
1770
1771
1772
1773
1774
1775
1776
1777
1778
1779
1780
1781
1782
1783
1784
1785
1786
1787
1788
1789
1790
1791
1792
1793
1794
1795
1796
1797
1798
1799
1800
1801
1802
1803
1804
1805
1806
1807
1808
1809
1810
1811
1812
1813
1814
1815
1816
1817
1818
1819
1820
1821
1822
1823
1824
1825
1826
1827
1828
1829
1830
1831
1832
1833
1834
1835
1836
1837
1838
1839
1840
1841
1842
1843
1844
1845
1846
1847
1848
1849
1850
1851
1852
1853
1854
1855
1856
1857
1858
1859
1860
1861
1862
1863
1864
1865
1866
1867
1868
1869
1870
1871
1872
1873
1874
1875
1876
1877
1878
1879
1880
1881
1882
1883
1884
1885
1886
1887
1888
1889
1890
1891
1892
1893
1894
1895
1896
1897
1898
1899
1900
1901
1902
1903
1904
1905
1906
1907
1908
1909
1910
1911
1912
1913
1914
1915
1916
1917
1918
1919
1920
1921
1922
1923
1924
1925
1926
1927
1928
1929
1930
1931
1932
1933
1934
1935
1936
1937
1938
1939
1940
1941
1942
1943
1944
1945
1946
1947
1948
1949
1950
1951
1952
1953
1954
1955
1956
1957
1958
1959
1960
1961
1962
1963
1964
1965
1966
1967
1968
1969
1970
1971
1972
1973
1974
1975
1976
1977
1978
1979
1980
1981
1982
1983
1984
1985
1986
1987
1988
1989
1990
1991
1992
1993
1994
1995
1996
1997
1998
1999
2000
2001
2002
2003
2004
2005
2006
2007
2008
2009
2010
2011
2012
2013
2014
2015
2016
2017
2018
2019
2020
2021
2022
2023
2024
2025
2026
2027
2028
2029
2030
2031
2032
2033
2034
2035
2036
2037
2038
2039
2040
2041
2042
2043
2044
2045
2046
2047
2048
2049
2050
2051
2052
2053
2054
2055
2056
2057
2058
2059
2060
2061
2062
2063
2064
2065
2066
2067
2068
2069
2070
2071
2072
2073
2074
2075
2076
2077
2078
2079
2080
2081
2082
2083
2084
2085
2086
2087
2088
2089
2090
2091
2092
2093
2094
2095
2096
2097
2098
2099
2100
2101
2102
2103
2104
2105
2106
2107
2108
2109
2110
2111
2112
2113
2114
2115
2116
2117
2118
2119
2120
2121
2122
2123
2124
2125
2126
2127
2128
2129
2130
2131
2132
2133
2134
2135
2136
2137
2138
2139
2140
2141
2142
2143
2144
2145
2146
2147
2148
2149
2150
2151
2152
2153
2154
2155
2156
2157
2158
2159
2160
2161
2162
2163
2164
2165
2166
2167
2168
2169
2170
2171
2172
2173
2174
2175
2176
2177
2178
2179
2180
2181
2182
2183
2184
2185
2186
2187
2188
2189
2190
2191
2192
2193
2194
2195
2196
2197
2198
2199
2200
2201
2202
2203
2204
2205
2206
2207
2208
2209
2210
2211
2212
2213
2214
2215
2216
2217
2218
2219
2220
2221
2222
2223
2224
2225
2226
2227
2228
2229
2230
2231
2232
2233
2234
2235
2236
2237
2238
2239
2240
2241
2242
2243
2244
2245
2246
2247
2248
2249
2250
2251
2252
2253
2254
2255
2256
2257
2258
2259
2260
2261
2262
2263
2264
2265
2266
2267
2268
2269
2270
2271
2272
2273
2274
2275
2276
2277
2278
2279
2280
2281
2282
2283
2284
2285
2286
2287
2288
2289
2290
2291
2292
2293
2294
2295
2296
2297
2298
2299
2300
2301
2302
2303
2304
2305
if not modules then modules = { } end modules ['font-cff'] = {
    version   = 1.001,
    comment   = "companion to font-ini.mkiv",
    author    = "Hans Hagen, PRAGMA-ADE, Hasselt NL",
    copyright = "PRAGMA ADE / ConTeXt Development Team",
    license   = "see context related readme files"
}

-- todo: option.outlines
-- todo: option.boundingbox
-- per charstring (less memory)

-- This is a heavy one as it is a rather packed format. We don't need al the information
-- now but we might need it later (who know what magic we can do with metapost). So at
-- some point this might become a module. We just follow Adobe Technical Notes #5176 and
-- #5177. In case of doubt I looked in the fontforge code that comes with LuaTeX but
-- it's not the easiest source to read (and doesn't cover cff2).

-- For now we save the segments in a list of segments with the operator last in an entry
-- because that reflects the original. But it might make more sense to use a single array
-- per segment. For pdf a simple concat works ok, but for other purposes a operator first
-- flush is nicer.
--
-- In retrospect I could have looked into the backend code of LuaTeX but it never
-- occurred to me that parsing charstrings was needed there (which has to to
-- with merging subroutines and flattening, not so much with calculations.) On
-- the other hand, we can now feed back cff2 stuff.

local next, type, tonumber = next, type, tonumber
local byte, char, gmatch = string.byte, string.char, string.gmatch
local concat, remove = table.concat, table.remove
local floor, abs, round, ceil, min, max = math.floor, math.abs, math.round, math.ceil, math.min, math.max
local P, C, R, S, C, Cs, Ct = lpeg.P, lpeg.C, lpeg.R, lpeg.S, lpeg.C, lpeg.Cs, lpeg.Ct
local lpegmatch = lpeg.match
local formatters = string.formatters
local bytetable = string.bytetable

local readers           = fonts.handlers.otf.readers
local streamreader      = readers.streamreader

local readstring        = streamreader.readstring
local readbyte          = streamreader.readcardinal1  --  8-bit unsigned integer
local readushort        = streamreader.readcardinal2  -- 16-bit unsigned integer
local readuint          = streamreader.readcardinal3  -- 24-bit unsigned integer
local readulong         = streamreader.readcardinal4  -- 32-bit unsigned integer
local setposition       = streamreader.setposition
local getposition       = streamreader.getposition
local readbytetable     = streamreader.readbytetable

local setmetatableindex = table.setmetatableindex

local trace_charstrings = false trackers.register("fonts.cff.charstrings",function(v) trace_charstrings = v end)
local report            = logs.reporter("otf reader","cff")

local parsedictionaries
local parsecharstring
local parsecharstrings
local resetcharstrings
local parseprivates
local startparsing
local stopparsing

local defaultstrings = { [0] = -- taken from ff
    ".notdef", "space", "exclam", "quotedbl", "numbersign", "dollar", "percent",
    "ampersand", "quoteright", "parenleft", "parenright", "asterisk", "plus",
    "comma", "hyphen", "period", "slash", "zero", "one", "two", "three", "four",
    "five", "six", "seven", "eight", "nine", "colon", "semicolon", "less",
    "equal", "greater", "question", "at", "A", "B", "C", "D", "E", "F", "G", "H",
    "I", "J", "K", "L", "M", "N", "O", "P", "Q", "R", "S", "T", "U", "V", "W",
    "X", "Y", "Z", "bracketleft", "backslash", "bracketright", "asciicircum",
    "underscore", "quoteleft", "a", "b", "c", "d", "e", "f", "g", "h", "i", "j",
    "k", "l", "m", "n", "o", "p", "q", "r", "s", "t", "u", "v", "w", "x", "y",
    "z", "braceleft", "bar", "braceright", "asciitilde", "exclamdown", "cent",
    "sterling", "fraction", "yen", "florin", "section", "currency",
    "quotesingle", "quotedblleft", "guillemotleft", "guilsinglleft",
    "guilsinglright", "fi", "fl", "endash", "dagger", "daggerdbl",
    "periodcentered", "paragraph", "bullet", "quotesinglbase", "quotedblbase",
    "quotedblright", "guillemotright", "ellipsis", "perthousand", "questiondown",
    "grave", "acute", "circumflex", "tilde", "macron", "breve", "dotaccent",
    "dieresis", "ring", "cedilla", "hungarumlaut", "ogonek", "caron", "emdash",
    "AE", "ordfeminine", "Lslash", "Oslash", "OE", "ordmasculine", "ae",
    "dotlessi", "lslash", "oslash", "oe", "germandbls", "onesuperior",
    "logicalnot", "mu", "trademark", "Eth", "onehalf", "plusminus", "Thorn",
    "onequarter", "divide", "brokenbar", "degree", "thorn", "threequarters",
    "twosuperior", "registered", "minus", "eth", "multiply", "threesuperior",
    "copyright", "Aacute", "Acircumflex", "Adieresis", "Agrave", "Aring",
    "Atilde", "Ccedilla", "Eacute", "Ecircumflex", "Edieresis", "Egrave",
    "Iacute", "Icircumflex", "Idieresis", "Igrave", "Ntilde", "Oacute",
    "Ocircumflex", "Odieresis", "Ograve", "Otilde", "Scaron", "Uacute",
    "Ucircumflex", "Udieresis", "Ugrave", "Yacute", "Ydieresis", "Zcaron",
    "aacute", "acircumflex", "adieresis", "agrave", "aring", "atilde",
    "ccedilla", "eacute", "ecircumflex", "edieresis", "egrave", "iacute",
    "icircumflex", "idieresis", "igrave", "ntilde", "oacute", "ocircumflex",
    "odieresis", "ograve", "otilde", "scaron", "uacute", "ucircumflex",
    "udieresis", "ugrave", "yacute", "ydieresis", "zcaron", "exclamsmall",
    "Hungarumlautsmall", "dollaroldstyle", "dollarsuperior", "ampersandsmall",
    "Acutesmall", "parenleftsuperior", "parenrightsuperior", "twodotenleader",
    "onedotenleader", "zerooldstyle", "oneoldstyle", "twooldstyle",
    "threeoldstyle", "fouroldstyle", "fiveoldstyle", "sixoldstyle",
    "sevenoldstyle", "eightoldstyle", "nineoldstyle", "commasuperior",
    "threequartersemdash", "periodsuperior", "questionsmall", "asuperior",
    "bsuperior", "centsuperior", "dsuperior", "esuperior", "isuperior",
    "lsuperior", "msuperior", "nsuperior", "osuperior", "rsuperior", "ssuperior",
    "tsuperior", "ff", "ffi", "ffl", "parenleftinferior", "parenrightinferior",
    "Circumflexsmall", "hyphensuperior", "Gravesmall", "Asmall", "Bsmall",
    "Csmall", "Dsmall", "Esmall", "Fsmall", "Gsmall", "Hsmall", "Ismall",
    "Jsmall", "Ksmall", "Lsmall", "Msmall", "Nsmall", "Osmall", "Psmall",
    "Qsmall", "Rsmall", "Ssmall", "Tsmall", "Usmall", "Vsmall", "Wsmall",
    "Xsmall", "Ysmall", "Zsmall", "colonmonetary", "onefitted", "rupiah",
    "Tildesmall", "exclamdownsmall", "centoldstyle", "Lslashsmall",
    "Scaronsmall", "Zcaronsmall", "Dieresissmall", "Brevesmall", "Caronsmall",
    "Dotaccentsmall", "Macronsmall", "figuredash", "hypheninferior",
    "Ogoneksmall", "Ringsmall", "Cedillasmall", "questiondownsmall", "oneeighth",
    "threeeighths", "fiveeighths", "seveneighths", "onethird", "twothirds",
    "zerosuperior", "foursuperior", "fivesuperior", "sixsuperior",
    "sevensuperior", "eightsuperior", "ninesuperior", "zeroinferior",
    "oneinferior", "twoinferior", "threeinferior", "fourinferior",
    "fiveinferior", "sixinferior", "seveninferior", "eightinferior",
    "nineinferior", "centinferior", "dollarinferior", "periodinferior",
    "commainferior", "Agravesmall", "Aacutesmall", "Acircumflexsmall",
    "Atildesmall", "Adieresissmall", "Aringsmall", "AEsmall", "Ccedillasmall",
    "Egravesmall", "Eacutesmall", "Ecircumflexsmall", "Edieresissmall",
    "Igravesmall", "Iacutesmall", "Icircumflexsmall", "Idieresissmall",
    "Ethsmall", "Ntildesmall", "Ogravesmall", "Oacutesmall", "Ocircumflexsmall",
    "Otildesmall", "Odieresissmall", "OEsmall", "Oslashsmall", "Ugravesmall",
    "Uacutesmall", "Ucircumflexsmall", "Udieresissmall", "Yacutesmall",
    "Thornsmall", "Ydieresissmall", "001.000", "001.001", "001.002", "001.003",
    "Black", "Bold", "Book", "Light", "Medium", "Regular", "Roman", "Semibold",
}

local cffreaders = {
    readbyte,
    readushort,
    readuint,
    readulong,
}

-- The header contains information about its own size.

local function readheader(f)
    local offset = getposition(f)
    local major  = readbyte(f)
    local header = {
        offset = offset,
        major  = major,
        minor  = readbyte(f),
        size   = readbyte(f), -- headersize
    }
    if major == 1 then
        header.dsize = readbyte(f)   -- list of dict offsets
    elseif major == 2 then
        header.dsize = readushort(f) -- topdict size
    else
        -- I'm probably no longer around by then and we use AI's to
        -- handle this kind of stuff, if we typeset documents at all.
    end
    setposition(f,offset+header.size)
    return header
end

-- The indexes all look the same, so we share a loader. We could pass a handler
-- and run over the array but why bother, we only have a few uses.

local function readlengths(f,longcount)
    local count = longcount and readulong(f) or readushort(f)
    if count == 0 then
        return { }
    end
    local osize = readbyte(f)
    local read  = cffreaders[osize]
    if not read then
        report("bad offset size: %i",osize)
        return { }
    end
    local lengths  = { }
    local previous = read(f)
    for i=1,count do
        local offset = read(f)
        local length = offset - previous
        if length < 0 then
            report("bad offset: %i",length)
            length = 0
        end
        lengths[i] = length
        previous = offset
    end
    return lengths
end

-- There can be subfonts so names is an array. However, in our case it's always
-- one font. The same is true for the top dictionaries. Watch how we only load
-- the dictionary string as for interpretation we need to have the strings loaded
-- as well.

local function readfontnames(f)
    local names = readlengths(f)
    for i=1,#names do
        names[i] = readstring(f,names[i])
    end
    return names
end

local function readtopdictionaries(f)
    local dictionaries = readlengths(f)
    for i=1,#dictionaries do
        dictionaries[i] = readstring(f,dictionaries[i])
    end
    return dictionaries
end

-- Strings are added to a list of standard strings so we start the font specific
-- one with an offset. Strings are shared so we have one table.

local function readstrings(f)
    local lengths = readlengths(f)
    local strings = setmetatableindex({ }, defaultstrings)
    local index   = #defaultstrings
    for i=1,#lengths do
        index = index + 1
        strings[index] = readstring(f,lengths[i])
    end
    return strings
end

-- Parsing the dictionaries is delayed till we have the strings loaded. The parser
-- is stack based so the operands come before the operator (like in postscript).

-- local function delta(t)
--     local n = #t
--     if n > 1 then
--         local p = t[1]
--         for i=2,n do
--             local c = t[i]
--             t[i] = c + p
--             p = c
--         end
--     end
-- end

do

    -- We use a closure so that we don't need to pass too much around. For cff2 we can
    -- at some point use a simple version as there is less.

    local stack   = { }
    local top     = 0
    local result  = { }
    local strings = { }

    local p_single =
        P("\00") / function()
            result.version = strings[stack[top]] or "unset"
            top = 0
        end
      + P("\01") / function()
            result.notice = strings[stack[top]] or "unset"
            top = 0
        end
      + P("\02") / function()
            result.fullname = strings[stack[top]] or "unset"
            top = 0
        end
      + P("\03") / function()
            result.familyname = strings[stack[top]] or "unset"
            top = 0
        end
      + P("\04") / function()
            result.weight = strings[stack[top]] or "unset"
            top = 0
        end
      + P("\05") / function()
            result.fontbbox = { unpack(stack,1,4) }
            top = 0
        end
   -- + P("\06") / function() end -- bluevalues
   -- + P("\07") / function() end -- otherblues
   -- + P("\08") / function() end -- familyblues
   -- + P("\09") / function() end -- familyotherblues
   -- + P("\10") / function() end -- strhw
   -- + P("\11") / function() end -- stdvw
      + P("\13") / function()
            result.uniqueid = stack[top]
            top = 0
        end
      + P("\14") / function()
            result.xuid = concat(stack,"",1,top)
            top = 0
        end
      + P("\15") / function()
            result.charset = stack[top]
            top = 0
        end
      + P("\16") / function()
            result.encoding = stack[top]
            top = 0
        end
      + P("\17") / function() -- valid cff2
            result.charstrings = stack[top]
            top = 0
        end
      + P("\18") / function()
            result.private = {
                size   = stack[top-1],
                offset = stack[top],
            }
            top = 0
        end
      + P("\19") / function()
            result.subroutines = stack[top]
            top = 0 -- new, forgotten ?
        end
      + P("\20") / function()
            result.defaultwidthx = stack[top]
            top = 0 -- new, forgotten ?
        end
      + P("\21") / function()
            result.nominalwidthx = stack[top]
            top = 0 -- new, forgotten ?
        end
   -- + P("\22") / function() -- reserved
   --   end
   -- + P("\23") / function() -- reserved
   --   end
      + P("\24") / function() -- new in cff2
            result.vstore = stack[top]
            top = 0
        end
      + P("\25") / function() -- new in cff2
            result.maxstack = stack[top]
            top = 0
        end
   -- + P("\26") / function() -- reserved
   --   end
   -- + P("\27") / function() -- reserved
   --   end

    local p_double = P("\12") * (
        P("\00") / function()
            result.copyright = stack[top]
            top = 0
        end
      + P("\01") / function()
            result.monospaced = stack[top] == 1 and true or false -- isfixedpitch
            top = 0
        end
      + P("\02") / function()
            result.italicangle = stack[top]
            top = 0
        end
      + P("\03") / function()
            result.underlineposition = stack[top]
            top = 0
        end
      + P("\04") / function()
            result.underlinethickness = stack[top]
            top = 0
        end
      + P("\05") / function()
            result.painttype = stack[top]
            top = 0
        end
      + P("\06") / function()
            result.charstringtype = stack[top]
            top = 0
        end
      + P("\07") / function() -- valid cff2
            result.fontmatrix = { unpack(stack,1,6) }
            top = 0
        end
      + P("\08") / function()
            result.strokewidth = stack[top]
            top = 0
        end
      + P("\20") / function()
            result.syntheticbase = stack[top]
            top = 0
        end
      + P("\21") / function()
            result.postscript = strings[stack[top]] or "unset"
            top = 0
        end
      + P("\22") / function()
            result.basefontname = strings[stack[top]] or "unset"
            top = 0
        end
      + P("\21") / function()
            result.basefontblend = stack[top]
            top = 0
        end
      + P("\30") / function()
            result.cid.registry   = strings[stack[top-2]] or "unset"
            result.cid.ordering   = strings[stack[top-1]] or "unset"
            result.cid.supplement = stack[top]
            top = 0
        end
      + P("\31") / function()
            result.cid.fontversion = stack[top]
            top = 0
        end
      + P("\32") / function()
            result.cid.fontrevision= stack[top]
            top = 0
        end
      + P("\33") / function()
            result.cid.fonttype = stack[top]
            top = 0
        end
      + P("\34") / function()
            result.cid.count = stack[top]
            top = 0
        end
      + P("\35") / function()
            result.cid.uidbase = stack[top]
            top = 0
        end
      + P("\36") / function() -- valid cff2
            result.cid.fdarray = stack[top]
            top = 0
        end
      + P("\37") / function() -- valid cff2
            result.cid.fdselect = stack[top]
            top = 0
        end
      + P("\38") / function()
            result.cid.fontname = strings[stack[top]] or "unset"
            top = 0
        end
    )

    -- Some lpeg fun ... a first variant split the byte and made a new string but
    -- the second variant is much faster. Not that it matters much as we don't see
    -- such numbers often.

    local p_last = P("\x0F") / "0" + P("\x1F") / "1" + P("\x2F") / "2"  + P("\x3F") / "3"
        + P("\x4F") / "4" + P("\x5F") / "5" + P("\x6F") / "6"  + P("\x7F") / "7"
        + P("\x8F") / "8" + P("\x9F") / "9" + P("\xAF") / ""   + P("\xBF") / ""
        + P("\xCF") / ""  + P("\xDF") / ""  + P("\xEF") / ""   + R("\xF0\xFF") / ""

 -- local remap = { [0] =
 --     "00",  "01",  "02",  "03",  "04",  "05",  "06",  "07",  "08",  "09",  "0.",  "0E",  "0E-",  "0",  "0-",  "0",
 --     "10",  "11",  "12",  "13",  "14",  "15",  "16",  "17",  "18",  "19",  "0.",  "0E",  "0E-",  "0",  "0-",  "0",
 --     "20",  "21",  "22",  "23",  "24",  "25",  "26",  "27",  "28",  "29",  "0.",  "0E",  "0E-",  "0",  "0-",  "0",
 --     "30",  "31",  "32",  "33",  "34",  "35",  "36",  "37",  "38",  "39",  "0.",  "0E",  "0E-",  "0",  "0-",  "0",
 --     "40",  "41",  "42",  "43",  "44",  "45",  "46",  "47",  "48",  "49",  "0.",  "0E",  "0E-",  "0",  "0-",  "0",
 --     "50",  "51",  "52",  "53",  "54",  "55",  "56",  "57",  "58",  "59",  "0.",  "0E",  "0E-",  "0",  "0-",  "0",
 --     "60",  "61",  "62",  "63",  "64",  "65",  "66",  "67",  "68",  "69",  "0.",  "0E",  "0E-",  "0",  "0-",  "0",
 --     "70",  "71",  "72",  "73",  "74",  "75",  "76",  "77",  "78",  "79",  "0.",  "0E",  "0E-",  "0",  "0-",  "0",
 --     "80",  "81",  "82",  "83",  "84",  "85",  "86",  "87",  "88",  "89",  "0.",  "0E",  "0E-",  "0",  "0-",  "0",
 --     "90",  "91",  "92",  "93",  "94",  "95",  "96",  "97",  "98",  "99",  "0.",  "0E",  "0E-",  "0",  "0-",  "0",
 --     ".0",  ".1",  ".2",  ".3",  ".4",  ".5",  ".6",  ".7",  ".8",  ".9",  "..",  ".E",  ".E-",  ".",  ".-",  ".",
 --     "E0",  "E1",  "E2",  "E3",  "E4",  "E5",  "E6",  "E7",  "E8",  "E9",  "E.",  "EE",  "EE-",  "E",  "E-",  "E",
 --     "E-0", "E-1", "E-2", "E-3", "E-4", "E-5", "E-6", "E-7", "E-8", "E-9", "E-.", "E-E", "E-E-", "E-", "E--", "E-",
 --     "-0",  "-1",  "-2",  "-3",  "-4",  "-5",  "-6",  "-7",  "-8",  "-9",  "-.",  "-E",  "-E-",  "-",  "--",  "-",
 -- }

 -- local p_nibbles = Cs(((1-p_last)/byte/remap)^0+p_last)

 -- local p = P("\30") * p_nibbles / function(t)
 --     print(tonumber(t))
 -- end

    local remap = {
        ["\x00"] = "00",  ["\x01"] = "01",  ["\x02"] = "02",  ["\x03"] = "03",  ["\x04"] = "04",  ["\x05"] = "05",  ["\x06"] = "06",  ["\x07"] = "07",  ["\x08"] = "08",  ["\x09"] = "09",  ["\x0A"] = "0.",  ["\x0B"] = "0E",  ["\x0C"] = "0E-",  ["\x0D"] = "0",  ["\x0E"] = "0-",  ["\x0F"] = "0",
        ["\x10"] = "10",  ["\x11"] = "11",  ["\x12"] = "12",  ["\x13"] = "13",  ["\x14"] = "14",  ["\x15"] = "15",  ["\x16"] = "16",  ["\x17"] = "17",  ["\x18"] = "18",  ["\x19"] = "19",  ["\x1A"] = "0.",  ["\x1B"] = "0E",  ["\x1C"] = "0E-",  ["\x1D"] = "0",  ["\x1E"] = "0-",  ["\x1F"] = "0",
        ["\x20"] = "20",  ["\x21"] = "21",  ["\x22"] = "22",  ["\x23"] = "23",  ["\x24"] = "24",  ["\x25"] = "25",  ["\x26"] = "26",  ["\x27"] = "27",  ["\x28"] = "28",  ["\x29"] = "29",  ["\x2A"] = "0.",  ["\x2B"] = "0E",  ["\x2C"] = "0E-",  ["\x2D"] = "0",  ["\x2E"] = "0-",  ["\x2F"] = "0",
        ["\x30"] = "30",  ["\x31"] = "31",  ["\x32"] = "32",  ["\x33"] = "33",  ["\x34"] = "34",  ["\x35"] = "35",  ["\x36"] = "36",  ["\x37"] = "37",  ["\x38"] = "38",  ["\x39"] = "39",  ["\x3A"] = "0.",  ["\x3B"] = "0E",  ["\x3C"] = "0E-",  ["\x3D"] = "0",  ["\x3E"] = "0-",  ["\x3F"] = "0",
        ["\x40"] = "40",  ["\x41"] = "41",  ["\x42"] = "42",  ["\x43"] = "43",  ["\x44"] = "44",  ["\x45"] = "45",  ["\x46"] = "46",  ["\x47"] = "47",  ["\x48"] = "48",  ["\x49"] = "49",  ["\x4A"] = "0.",  ["\x4B"] = "0E",  ["\x4C"] = "0E-",  ["\x4D"] = "0",  ["\x4E"] = "0-",  ["\x4F"] = "0",
        ["\x50"] = "50",  ["\x51"] = "51",  ["\x52"] = "52",  ["\x53"] = "53",  ["\x54"] = "54",  ["\x55"] = "55",  ["\x56"] = "56",  ["\x57"] = "57",  ["\x58"] = "58",  ["\x59"] = "59",  ["\x5A"] = "0.",  ["\x5B"] = "0E",  ["\x5C"] = "0E-",  ["\x5D"] = "0",  ["\x5E"] = "0-",  ["\x5F"] = "0",
        ["\x60"] = "60",  ["\x61"] = "61",  ["\x62"] = "62",  ["\x63"] = "63",  ["\x64"] = "64",  ["\x65"] = "65",  ["\x66"] = "66",  ["\x67"] = "67",  ["\x68"] = "68",  ["\x69"] = "69",  ["\x6A"] = "0.",  ["\x6B"] = "0E",  ["\x6C"] = "0E-",  ["\x6D"] = "0",  ["\x6E"] = "0-",  ["\x6F"] = "0",
        ["\x70"] = "70",  ["\x71"] = "71",  ["\x72"] = "72",  ["\x73"] = "73",  ["\x74"] = "74",  ["\x75"] = "75",  ["\x76"] = "76",  ["\x77"] = "77",  ["\x78"] = "78",  ["\x79"] = "79",  ["\x7A"] = "0.",  ["\x7B"] = "0E",  ["\x7C"] = "0E-",  ["\x7D"] = "0",  ["\x7E"] = "0-",  ["\x7F"] = "0",
        ["\x80"] = "80",  ["\x81"] = "81",  ["\x82"] = "82",  ["\x83"] = "83",  ["\x84"] = "84",  ["\x85"] = "85",  ["\x86"] = "86",  ["\x87"] = "87",  ["\x88"] = "88",  ["\x89"] = "89",  ["\x8A"] = "0.",  ["\x8B"] = "0E",  ["\x8C"] = "0E-",  ["\x8D"] = "0",  ["\x8E"] = "0-",  ["\x8F"] = "0",
        ["\x90"] = "90",  ["\x91"] = "91",  ["\x92"] = "92",  ["\x93"] = "93",  ["\x94"] = "94",  ["\x95"] = "95",  ["\x96"] = "96",  ["\x97"] = "97",  ["\x98"] = "98",  ["\x99"] = "99",  ["\x9A"] = "0.",  ["\x9B"] = "0E",  ["\x9C"] = "0E-",  ["\x9D"] = "0",  ["\x9E"] = "0-",  ["\x9F"] = "0",
        ["\xA0"] = ".0",  ["\xA1"] = ".1",  ["\xA2"] = ".2",  ["\xA3"] = ".3",  ["\xA4"] = ".4",  ["\xA5"] = ".5",  ["\xA6"] = ".6",  ["\xA7"] = ".7",  ["\xA8"] = ".8",  ["\xA9"] = ".9",  ["\xAA"] = "..",  ["\xAB"] = ".E",  ["\xAC"] = ".E-",  ["\xAD"] = ".",  ["\xAE"] = ".-",  ["\xAF"] = ".",
        ["\xB0"] = "E0",  ["\xB1"] = "E1",  ["\xB2"] = "E2",  ["\xB3"] = "E3",  ["\xB4"] = "E4",  ["\xB5"] = "E5",  ["\xB6"] = "E6",  ["\xB7"] = "E7",  ["\xB8"] = "E8",  ["\xB9"] = "E9",  ["\xBA"] = "E.",  ["\xBB"] = "EE",  ["\xBC"] = "EE-",  ["\xBD"] = "E",  ["\xBE"] = "E-",  ["\xBF"] = "E",
        ["\xC0"] = "E-0", ["\xC1"] = "E-1", ["\xC2"] = "E-2", ["\xC3"] = "E-3", ["\xC4"] = "E-4", ["\xC5"] = "E-5", ["\xC6"] = "E-6", ["\xC7"] = "E-7", ["\xC8"] = "E-8", ["\xC9"] = "E-9", ["\xCA"] = "E-.", ["\xCB"] = "E-E", ["\xCC"] = "E-E-", ["\xCD"] = "E-", ["\xCE"] = "E--", ["\xCF"] = "E-",
        ["\xD0"] = "-0",  ["\xD1"] = "-1",  ["\xD2"] = "-2",  ["\xD3"] = "-3",  ["\xD4"] = "-4",  ["\xD5"] = "-5",  ["\xD6"] = "-6",  ["\xD7"] = "-7",  ["\xD8"] = "-8",  ["\xD9"] = "-9",  ["\xDA"] = "-.",  ["\xDB"] = "-E",  ["\xDC"] = "-E-",  ["\xDD"] = "-",  ["\xDE"] = "--",  ["\xDF"] = "-",
    }

    local p_nibbles = P("\30") * Cs(((1-p_last)/remap)^0+p_last) / function(n)
        -- 0-9=digit a=. b=E c=E- d=reserved e=- f=finish
        top = top + 1
        stack[top] = tonumber(n) or 0
    end

    local p_byte = C(R("\32\246")) / function(b0)
        -- -107 .. +107
        top = top + 1
        stack[top] = byte(b0) - 139
    end

    local p_positive =  C(R("\247\250")) * C(1) / function(b0,b1)
        -- +108 .. +1131
        top = top + 1
        stack[top] = (byte(b0)-247)*256 + byte(b1) + 108
    end

    local p_negative = C(R("\251\254")) * C(1) / function(b0,b1)
        -- -1131 .. -108
        top = top + 1
        stack[top] = -(byte(b0)-251)*256 - byte(b1) - 108
    end

    local p_short = P("\28") * C(1) * C(1) / function(b1,b2)
        -- -32768 .. +32767 : b1<<8 | b2
        top = top + 1
        local n = 0x100 * byte(b1) + byte(b2)
        if n  >= 0x8000 then
            stack[top] = n - 0xFFFF - 1
        else
            stack[top] =  n
        end
    end

    local p_long = P("\29") * C(1) * C(1) * C(1) * C(1) / function(b1,b2,b3,b4)
        -- -2^31 .. +2^31-1 : b1<<24 | b2<<16 | b3<<8 | b4
        top = top + 1
        local n = 0x1000000 * byte(b1) + 0x10000 * byte(b2) + 0x100 * byte(b3) + byte(b4)
        if n >= 0x8000000 then
            stack[top] = n - 0xFFFFFFFF - 1
        else
            stack[top] = n
        end
    end

    local p_unsupported = P(1) / function(detail)
        top = 0
    end

    local p_dictionary = (
        p_byte
      + p_positive
      + p_negative
      + p_short
      + p_long
      + p_nibbles
      + p_single
      + p_double
      + p_unsupported
    )^1

    parsedictionaries = function(data,dictionaries,what)
        stack   = { }
        strings = data.strings
        for i=1,#dictionaries do
            top    = 0
            result = what == "cff" and {
                monospaced         = false,
                italicangle        = 0,
                underlineposition  = -100,
                underlinethickness = 50,
                painttype          = 0,
                charstringtype     = 2,
                fontmatrix         = { 0.001, 0, 0, 0.001, 0, 0 },
                fontbbox           = { 0, 0, 0, 0 },
                strokewidth        = 0,
                charset            = 0,
                encoding           = 0,
                cid = {
                    fontversion     = 0,
                    fontrevision    = 0,
                    fonttype        = 0,
                    count           = 8720,
                }
            } or {
                charstringtype     = 2,
                charset            = 0,
                vstore             = 0,
                cid = {
                    -- nothing yet
                },
            }
            lpegmatch(p_dictionary,dictionaries[i])
            dictionaries[i] = result
        end
        --
        result = { }
        top    = 0
        stack  = { }
    end

    parseprivates = function(data,dictionaries)
        stack   = { }
        strings = data.strings
        for i=1,#dictionaries do
            local private = dictionaries[i].private
            if private and private.data then
                top     = 0
                result  = {
                    forcebold         = false,
                    languagegroup     = 0,
                    expansionfactor   = 0.06,
                    initialrandomseed = 0,
                    subroutines       = 0,
                    defaultwidthx     = 0,
                    nominalwidthx     = 0,
                    cid               = {
                        -- actually an error
                    },
                }
                lpegmatch(p_dictionary,private.data)
                private.data = result
            end
        end
        result = { }
        top    = 0
        stack  = { }
    end

    -- All bezier curves have 6 points with successive pairs relative to
    -- the previous pair. Some can be left out and are then copied or zero
    -- (optimization).
    --
    -- We are not really interested in all the details of a glyph because we
    -- only need to calculate the boundingbox. So, todo: a quick no result but
    -- calculate only variant.
    --
    -- The conversion is straightforward and the specification os clear once
    -- you understand that the x and y needs to be updates each step. It's also
    -- quite easy to test because in mp a shape will look bad when a few variables
    -- are swapped. But still there might be bugs down here because not all
    -- variants are seen in a font so far. We are less compact that the ff code
    -- because there quite some variants are done in one helper with a lot of
    -- testing for states.

    local x            = 0
    local y            = 0
    local width        = false
    local r            = 0
    local stems        = 0
    local globalbias   = 0
    local localbias    = 0
    local nominalwidth = 0
    local defaultwidth = 0
    local charset      = false
    local globals      = false
    local locals       = false
    local depth        = 1
    local xmin         = 0
    local xmax         = 0
    local ymin         = 0
    local ymax         = 0
    local checked      = false
    local keepcurve    = false
    local version      = 2
    local regions      = false
    local nofregions   = 0
    local region       = false
    local factors      = false
    local axis         = false
    local vsindex      = 0

    local function showstate(where)
        report("%w%-10s : [%s] n=%i",depth*2,where,concat(stack," ",1,top),top)
    end

    local function showvalue(where,value,showstack)
        if showstack then
            report("%w%-10s : %s : [%s] n=%i",depth*2,where,tostring(value),concat(stack," ",1,top),top)
        else
            report("%w%-10s : %s",depth*2,where,tostring(value))
        end
    end

    -- All these indirect calls make this run slower but it's cleaner this way
    -- and we cache the result. As we moved the boundingbox code inline we gain
    -- some back. I inlined some of then and a bit speed can be gained by more
    -- inlining but not that much.

    local function xymoveto()
        if keepcurve then
            r = r + 1
            result[r] = { x, y, "m" }
        end
        if checked then
            if x > xmax then xmax = x elseif x < xmin then xmin = x end
            if y > ymax then ymax = y elseif y < ymin then ymin = y end
        else
            xmin = x
            ymin = y
            xmax = x
            ymax = y
            checked = true
        end
    end

    local function xmoveto() -- slight speedup
        if keepcurve then
            r = r + 1
            result[r] = { x, y, "m" }
        end
        if not checked then
            xmin = x
            ymin = y
            xmax = x
            ymax = y
            checked = true
        elseif x > xmax then
            xmax = x
        elseif x < xmin then
            xmin = x
        end
    end

    local function ymoveto() -- slight speedup
        if keepcurve then
            r = r + 1
            result[r] = { x, y, "m" }
        end
        if not checked then
            xmin = x
            ymin = y
            xmax = x
            ymax = y
            checked = true
        elseif y > ymax then
            ymax = y
        elseif y < ymin then
            ymin = y
        end
    end

    local function moveto()
        if trace_charstrings then
            showstate("moveto")
        end
        top = 0 -- forgotten
        xymoveto()
    end

    local function xylineto() -- we could inline, no blend
        if keepcurve then
            r = r + 1
            result[r] = { x, y, "l" }
        end
        if checked then
            if x > xmax then xmax = x elseif x < xmin then xmin = x end
            if y > ymax then ymax = y elseif y < ymin then ymin = y end
        else
            xmin = x
            ymin = y
            xmax = x
            ymax = y
            checked = true
        end
    end

    local function xlineto() -- slight speedup
        if keepcurve then
            r = r + 1
            result[r] = { x, y, "l" }
        end
        if not checked then
            xmin = x
            ymin = y
            xmax = x
            ymax = y
            checked = true
        elseif x > xmax then
            xmax = x
        elseif x < xmin then
            xmin = x
        end
    end

    local function ylineto() -- slight speedup
        if keepcurve then
            r = r + 1
            result[r] = { x, y, "l" }
        end
        if not checked then
            xmin = x
            ymin = y
            xmax = x
            ymax = y
            checked = true
        elseif y > ymax then
            ymax = y
        elseif y < ymin then
            ymin = y
        end
    end

    local function xycurveto(x1,y1,x2,y2,x3,y3) -- called local so no blend here
        if trace_charstrings then
            showstate("curveto")
        end
        if keepcurve then
            r = r + 1
            result[r] = { x1, y1, x2, y2, x3, y3, "c" }
        end
        if checked then
            if x1 > xmax then xmax = x1 elseif x1 < xmin then xmin = x1 end
            if y1 > ymax then ymax = y1 elseif y1 < ymin then ymin = y1 end
        else
            xmin = x1
            ymin = y1
            xmax = x1
            ymax = y1
            checked = true
        end
        if x2 > xmax then xmax = x2 elseif x2 < xmin then xmin = x2 end
        if y2 > ymax then ymax = y2 elseif y2 < ymin then ymin = y2 end
        if x3 > xmax then xmax = x3 elseif x3 < xmin then xmin = x3 end
        if y3 > ymax then ymax = y3 elseif y3 < ymin then ymin = y3 end
    end

    local function rmoveto()
        if not width then
            if top > 2 then
                width = stack[1]
                if trace_charstrings then
                    showvalue("backtrack width",width)
                end
            else
                width = true
            end
        end
        if trace_charstrings then
            showstate("rmoveto")
        end
        x = x + stack[top-1] -- dx1
        y = y + stack[top]   -- dy1
        top = 0
        xymoveto()
    end

    local function hmoveto()
        if not width then
            if top > 1 then
                width = stack[1]
                if trace_charstrings then
                    showvalue("backtrack width",width)
                end
            else
                width = true
            end
        end
        if trace_charstrings then
            showstate("hmoveto")
        end
        x = x + stack[top] -- dx1
        top = 0
        xmoveto()
    end

    local function vmoveto()
        if not width then
            if top > 1 then
                width = stack[1]
                if trace_charstrings then
                    showvalue("backtrack width",width)
                end
            else
                width = true
            end
        end
        if trace_charstrings then
            showstate("vmoveto")
        end
        y = y + stack[top] -- dy1
        top = 0
        ymoveto()
    end

    local function rlineto()
        if trace_charstrings then
            showstate("rlineto")
        end
        for i=1,top,2 do
            x = x + stack[i]   -- dxa
            y = y + stack[i+1] -- dya
            xylineto()
        end
        top = 0
    end

    local function hlineto() -- x (y,x)+ | (x,y)+
        if trace_charstrings then
            showstate("hlineto")
        end
        if top == 1 then
            x = x + stack[1]
            xlineto()
        else
            local swap = true
            for i=1,top do
                if swap then
                    x = x + stack[i]
                    xlineto()
                    swap = false
                else
                    y = y + stack[i]
                    ylineto()
                    swap = true
                end
            end
        end
        top = 0
    end

    local function vlineto() -- y (x,y)+ | (y,x)+
        if trace_charstrings then
            showstate("vlineto")
        end
        if top == 1 then
            y = y + stack[1]
            ylineto()
        else
            local swap = false
            for i=1,top do
                if swap then
                    x = x + stack[i]
                    xlineto()
                    swap = false
                else
                    y = y + stack[i]
                    ylineto()
                    swap = true
                end
            end
        end
        top = 0
    end

    local function rrcurveto()
        if trace_charstrings then
            showstate("rrcurveto")
        end
        for i=1,top,6 do
            local ax = x  + stack[i]   -- dxa
            local ay = y  + stack[i+1] -- dya
            local bx = ax + stack[i+2] -- dxb
            local by = ay + stack[i+3] -- dyb
            x = bx + stack[i+4]        -- dxc
            y = by + stack[i+5]        -- dyc
            xycurveto(ax,ay,bx,by,x,y)
        end
        top = 0
    end

    local function hhcurveto()
        if trace_charstrings then
            showstate("hhcurveto")
        end
        local s = 1
        if top % 2 ~= 0 then
            y = y + stack[1]           -- dy1
            s = 2
        end
        for i=s,top,4 do
            local ax = x + stack[i]    -- dxa
            local ay = y
            local bx = ax + stack[i+1] -- dxb
            local by = ay + stack[i+2] -- dyb
            x = bx + stack[i+3]        -- dxc
            y = by
            xycurveto(ax,ay,bx,by,x,y)
        end
        top = 0
    end

    local function vvcurveto()
        if trace_charstrings then
            showstate("vvcurveto")
        end
        local s = 1
        local d = 0
        if top % 2 ~= 0 then
            d = stack[1]               -- dx1
            s = 2
        end
        for i=s,top,4 do
            local ax = x + d
            local ay = y + stack[i]    -- dya
            local bx = ax + stack[i+1] -- dxb
            local by = ay + stack[i+2] -- dyb
            x = bx
            y = by + stack[i+3]        -- dyc
            xycurveto(ax,ay,bx,by,x,y)
            d = 0
        end
        top = 0
    end

--     local function xxcurveto(swap)
--         local last = top % 4 ~= 0 and stack[top]
--         if last then
--             top = top - 1
--         end
--         for i=1,top,4 do
--             local ax, ay, bx, by
--             if swap then
--                 ax = x  + stack[i]
--                 ay = y
--                 bx = ax + stack[i+1]
--                 by = ay + stack[i+2]
--                 y  = by + stack[i+3]
--                 if last and i+3 == top then
--                     x = bx + last
--                 else
--                     x = bx
--                 end
--                 swap = false
--             else
--                 ax = x
--                 ay = y  + stack[i]
--                 bx = ax + stack[i+1]
--                 by = ay + stack[i+2]
--                 x  = bx + stack[i+3]
--                 if last and i+3 == top then
--                     y = by + last
--                 else
--                     y = by
--                 end
--                 swap = true
--             end
--             xycurveto(ax,ay,bx,by,x,y)
--         end
--         top = 0
--     end

    local function xxcurveto(swap)
        local last = top % 4 ~= 0 and stack[top]
        if last then
            top = top - 1
        end
        for i=1,top,4 do
            local ax, ay, bx, by
            if swap then
                ax = x  + stack[i]
                ay = y
                bx = ax + stack[i+1]
                by = ay + stack[i+2]
                y  = by + stack[i+3]
                if last and i+3 == top then
                    x = bx + last
                else
                    x = bx
                end
                swap = false
            else
                ax = x
                ay = y  + stack[i]
                bx = ax + stack[i+1]
                by = ay + stack[i+2]
                x  = bx + stack[i+3]
                if last and i+3 == top then
                    y = by + last
                else
                    y = by
                end
                swap = true
            end
            xycurveto(ax,ay,bx,by,x,y)
        end
        top = 0
    end


    local function hvcurveto()
        if trace_charstrings then
            showstate("hvcurveto")
        end
        xxcurveto(true)
    end

    local function vhcurveto()
        if trace_charstrings then
            showstate("vhcurveto")
        end
        xxcurveto(false)
    end

    local function rcurveline()
        if trace_charstrings then
            showstate("rcurveline")
        end
        for i=1,top-2,6 do
            local ax = x  + stack[i]   -- dxa
            local ay = y  + stack[i+1] -- dya
            local bx = ax + stack[i+2] -- dxb
            local by = ay + stack[i+3] -- dyb
            x = bx + stack[i+4] -- dxc
            y = by + stack[i+5] -- dyc
            xycurveto(ax,ay,bx,by,x,y)
        end
        x = x + stack[top-1] -- dxc
        y = y + stack[top]   -- dyc
        xylineto()
        top = 0
    end

    local function rlinecurve()
        if trace_charstrings then
            showstate("rlinecurve")
        end
        if top > 6 then
            for i=1,top-6,2 do
                x = x + stack[i]
                y = y + stack[i+1]
                xylineto()
            end
        end
        local ax = x  + stack[top-5]
        local ay = y  + stack[top-4]
        local bx = ax + stack[top-3]
        local by = ay + stack[top-2]
        x = bx + stack[top-1]
        y = by + stack[top]
        xycurveto(ax,ay,bx,by,x,y)
        top = 0
    end

    -- flex is not yet tested! no loop

    local function flex() -- fd not used
        if trace_charstrings then
            showstate("flex")
        end
        local ax = x  + stack[1]  -- dx1
        local ay = y  + stack[2]  -- dy1
        local bx = ax + stack[3]  -- dx2
        local by = ay + stack[4]  -- dy2
        local cx = bx + stack[5]  -- dx3
        local cy = by + stack[6]  -- dy3
        xycurveto(ax,ay,bx,by,cx,cy)
        local dx = cx + stack[7]  -- dx4
        local dy = cy + stack[8]  -- dy4
        local ex = dx + stack[9]  -- dx5
        local ey = dy + stack[10] -- dy5
        x = ex + stack[11]        -- dx6
        y = ey + stack[12]        -- dy6
        xycurveto(dx,dy,ex,ey,x,y)
        top = 0
    end

    local function hflex()
        if trace_charstrings then
            showstate("hflex")
        end
        local ax = x  + stack[1] -- dx1
        local ay = y
        local bx = ax + stack[2] -- dx2
        local by = ay + stack[3] -- dy2
        local cx = bx + stack[4] -- dx3
        local cy = by
        xycurveto(ax,ay,bx,by,cx,cy)
        local dx = cx + stack[5] -- dx4
        local dy = by
        local ex = dx + stack[6] -- dx5
        local ey = y
        x = ex + stack[7]        -- dx6
        xycurveto(dx,dy,ex,ey,x,y)
        top = 0
    end

    local function hflex1()
        if trace_charstrings then
            showstate("hflex1")
        end
        local ax = x  + stack[1] -- dx1
        local ay = y  + stack[2] -- dy1
        local bx = ax + stack[3] -- dx2
        local by = ay + stack[4] -- dy2
        local cx = bx + stack[5] -- dx3
        local cy = by
        xycurveto(ax,ay,bx,by,cx,cy)
        local dx = cx + stack[6] -- dx4
        local dy = by
        local ex = dx + stack[7] -- dx5
        local ey = dy + stack[8] -- dy5
        x = ex + stack[9]        -- dx6
        xycurveto(dx,dy,ex,ey,x,y)
        top = 0
    end

    local function flex1()
        if trace_charstrings then
            showstate("flex1")
        end
        local ax = x  + stack[1]  --dx1
        local ay = y  + stack[2]  --dy1
        local bx = ax + stack[3]  --dx2
        local by = ay + stack[4]  --dy2
        local cx = bx + stack[5]  --dx3
        local cy = by + stack[6]  --dy3
        xycurveto(ax,ay,bx,by,cx,cy)
        local dx = cx + stack[7]  --dx4
        local dy = cy + stack[8]  --dy4
        local ex = dx + stack[9]  --dx5
        local ey = dy + stack[10] --dy5
        if abs(ex - x) > abs(ey - y) then -- spec: abs(dx) > abs(dy)
            x = ex + stack[11]
        else
            y = ey + stack[11]
        end
        xycurveto(dx,dy,ex,ey,x,y)
        top = 0
    end

    local function getstem()
        if top == 0 then
            -- bad
        elseif top % 2 ~= 0 then
            if width then
                remove(stack,1)
            else
                width = remove(stack,1)
                if trace_charstrings then
                    showvalue("width",width)
                end
            end
            top = top - 1
        end
        if trace_charstrings then
            showstate("stem")
        end
        stems = stems + top/2
        top   = 0
    end

    local function getmask()
        if top == 0 then
            -- bad
        elseif top % 2 ~= 0 then
            if width then
                remove(stack,1)
            else
                width = remove(stack,1)
                if trace_charstrings then
                    showvalue("width",width)
                end
            end
            top = top - 1
        end
        if trace_charstrings then
            showstate(operator == 19 and "hintmark" or "cntrmask")
        end
        stems = stems + top/2
        top   = 0
        if stems == 0 then
            -- forget about it
        elseif stems <= 8 then
            return 1
        else
            return floor((stems+7)/8)
        end
    end

    local function unsupported(t)
        if trace_charstrings then
            showstate("unsupported " .. t)
        end
        top = 0
    end

    local function unsupportedsub(t)
        if trace_charstrings then
            showstate("unsupported sub " .. t)
        end
        top = 0
    end

    -- type 1 (not used in type 2)

    local function getstem3()
        if trace_charstrings then
            showstate("stem3")
        end
        top = 0
    end

    local function divide()
        if version == 1 then
            local d = stack[top]
            top = top - 1
            stack[top] = stack[top] / d
        end
    end

    local function closepath()
        if version == 1 then
            if trace_charstrings then
                showstate("closepath")
            end
        end
        top = 0
    end

    local function hsbw()
        if version == 1 then
            if trace_charstrings then
                showstate("dotsection")
            end
            width = stack[top]
        end
        top = 0
    end

    local function seac()
        if version == 1 then
            if trace_charstrings then
                showstate("seac")
            end
        end
        top = 0
    end

    local function sbw()
        if version == 1 then
            if trace_charstrings then
                showstate("sbw")
            end
            width = stack[top-1]
        end
        top = 0
    end

    -- these are probably used for special cases i.e. call out to postscript

    local function callothersubr()
        if version == 1 then
            -- we don't support this (ok, we could mimick these othersubs)
            if trace_charstrings then
                showstate("callothersubr (unsupported)")
            end
        end
        top = 0
    end

    local function pop()
        if version == 1 then
            -- we don't support this
            if trace_charstrings then
                showstate("pop (unsupported)")
            end
            top = top + 1
            stack[top] = 0 -- a dummy
        else
            top = 0
        end
    end

    local function setcurrentpoint()
        if version == 1 then
            -- we don't support this
            if trace_charstrings then
                showstate("pop (unsupported)")
            end
            x = x + stack[top-1]
            y = y + stack[top]
        end
        top = 0
    end

    -- So far for unsupported postscript. Now some cff2 magic. As I still need
    -- to wrap my head around the rather complex variable font specification
    -- with regions and axis, the following approach kind of works but is more
    -- some trial and error trick. It's still not clear how much of the complex
    -- truetype description applies to cff.

    local reginit = false

    local function updateregions(n) -- n + 1
        if regions then
            local current = regions[n] or regions[1]
            nofregions = #current
            if axis and n ~= reginit then
                factors = { }
                for i=1,nofregions do
                    local region = current[i]
                    local s = 1
                    for j=1,#axis do
                        local f = axis[j]
                        local r = region[j]
                        local start = r.start
                        local peak  = r.peak
                        local stop  = r.stop
                        if start > peak or peak > stop then
                            -- * 1
                        elseif start < 0 and stop > 0 and peak ~= 0 then
                            -- * 1
                        elseif peak == 0 then
                            -- * 1
                        elseif f < start or f > stop then
                            -- * 0
                            s = 0
                            break
                        elseif f < peak then
                            s = s * (f - start) / (peak - start)
                        elseif f > peak then
                            s = s * (stop - f) / (stop - peak)
                        else
                            -- * 1
                        end
                    end
                    factors[i] = s
                end
            end
        end
        reginit = n
    end

    local function setvsindex()
        local vsindex = stack[top]
        if trace_charstrings then
            showstate(formatters["vsindex %i"](vsindex))
        end
        updateregions(vsindex)
        top = top - 1
    end

    local function blend()
        local n = stack[top]
        top = top - 1
        if axis then
            --  x    (r1x,r2x,r3x)
            -- (x,y) (r1x,r2x,r3x) (r1y,r2y,r3y)
            if trace_charstrings then
                local t = top - nofregions * n
                local m = t - n
                for i=1,n do
                    local k   = m + i
                    local d   = m + n + (i-1)*nofregions
                    local old = stack[k]
                    local new = old
                    for r=1,nofregions do
                        new = new + stack[d+r] * factors[r]
                    end
                    stack[k] = new
                    showstate(formatters["blend %i of %i: %s -> %s"](i,n,old,new))
                end
                top = t
            elseif n == 1 then
                top = top - nofregions
                local v = stack[top]
                for r=1,nofregions do
                    v = v + stack[top+r] * factors[r]
                end
                stack[top] = v
            else
                top = top - nofregions * n
                local d = top
                local k = top - n
                for i=1,n do
                    k = k + 1
                    local v = stack[k]
                    for r=1,nofregions do
                        v = v + stack[d+r] * factors[r]
                    end
                    stack[k] = v
                    d = d + nofregions
                end
            end
        else
            -- error
        end
    end

    -- Bah, we cannot use a fast lpeg because a hint has an unknown size and a
    -- runtime capture cannot handle that well.

    local actions = { [0] =
        unsupported,  --  0
        getstem,      --  1 -- hstem
        unsupported,  --  2
        getstem,      --  3 -- vstem
        vmoveto,      --  4
        rlineto,      --  5
        hlineto,      --  6
        vlineto,      --  7
        rrcurveto,    --  8
        unsupported,  --  9 -- closepath
        unsupported,  -- 10 -- calllocal,
        unsupported,  -- 11 -- callreturn,
        unsupported,  -- 12 -- elsewhere
        hsbw,         -- 13 -- hsbw (type 1 cff)
        unsupported,  -- 14 -- endchar,
        setvsindex,   -- 15 -- cff2
        blend,        -- 16 -- cff2
        unsupported,  -- 17
        getstem,      -- 18 -- hstemhm
        getmask,      -- 19 -- hintmask
        getmask,      -- 20 -- cntrmask
        rmoveto,      -- 21
        hmoveto,      -- 22
        getstem,      -- 23 -- vstemhm
        rcurveline,   -- 24
        rlinecurve,   -- 25
        vvcurveto,    -- 26
        hhcurveto,    -- 27
        unsupported,  -- 28 -- elsewhere
        unsupported,  -- 29 -- elsewhere
        vhcurveto,    -- 30
        hvcurveto,    -- 31
    }

    local subactions = {
        -- cff 1
        [000] = dotsection,
        [001] = getstem3,
        [002] = getstem3,
        [006] = seac,
        [007] = sbw,
        [012] = divide,
        [016] = callothersubr,
        [017] = pop,
        [033] = setcurrentpoint,
        -- cff 2
        [034] = hflex,
        [035] = flex,
        [036] = hflex1,
        [037] = flex1,
    }

    local c_endchar = char(14)

    local passon  do

        -- todo: round in blend
        -- todo: delay this hash

        local rshift = bit32.rshift
        local band = bit32.band
        local round = math.round

        local encode = table.setmetatableindex(function(t,i)
            for i=-2048,-1130 do
                t[i] = char(28,band(rshift(i,8),0xFF),band(i,0xFF))
            end
            for i=-1131,-108 do
                local v = 0xFB00 - i - 108
                t[i] = char(band(rshift(v,8),0xFF),band(v,0xFF))
            end
            for i=-107,107 do
                t[i] = char(i + 139)
            end
            for i=108,1131 do
                local v = 0xF700 + i - 108
                t[i] = char(band(rshift(v,8),0xFF),band(v,0xFF))
            end
            for i=1132,2048 do
                t[i] = char(28,band(rshift(i,8),0xFF),band(i,0xFF))
            end
            return t[i]
        end)

        local function setvsindex()
            local vsindex = stack[top]
            updateregions(vsindex)
            top = top - 1
        end

        local function blend()
            local n = stack[top]
            top = top - 1
            if not axis then
                -- fatal error
            elseif n == 1 then
                top = top - nofregions
                local v = stack[top]
                for r=1,nofregions do
                    v = v + stack[top+r] * factors[r]
                end
                stack[top] = round(v)
            else
                top = top - nofregions * n
                local d = top
                local k = top - n
                for i=1,n do
                    k = k + 1
                    local v = stack[k]
                    for r=1,nofregions do
                        v = v + stack[d+r] * factors[r]
                    end
                    stack[k] = round(v)
                    d = d + nofregions
                end
            end
        end

        passon = function(operation)
            if operation == 15 then
                setvsindex()
            elseif operation == 16 then
                blend()
            else
                for i=1,top do
                    r = r + 1
                    result[r] = encode[stack[i]]
                end
                r = r + 1
                result[r] = char(operation) -- maybe use a hash
                top = 0
            end
        end

    end

    -- end of experiment

    local process

    local function call(scope,list,bias) -- ,process)
        depth = depth + 1
        if top == 0 then
            showstate(formatters["unknown %s call"](scope))
            top = 0
        else
            local index = stack[top] + bias
            top = top - 1
            if trace_charstrings then
                showvalue(scope,index,true)
            end
            local tab = list[index]
            if tab then
                process(tab)
            else
                showstate(formatters["unknown %s call %i"](scope,index))
                top = 0
            end
        end
        depth = depth - 1
    end

    -- precompiling and reuse is much slower than redoing the calls

    local justpass = false

    process = function(tab)
        local i = 1
        local n = #tab
        while i <= n do
            local t = tab[i]
            if t >= 32 then
                top = top + 1
                if t <= 246 then
                    -- -107 .. +107
                    stack[top] = t - 139
                    i = i + 1
                elseif t <= 250 then
                    -- +108 .. +1131
                 -- stack[top] = (t-247)*256 + tab[i+1] + 108
                 -- stack[top] = t*256 - 247*256 + tab[i+1] + 108
                    stack[top] = t*256 - 63124 + tab[i+1]
                    i = i + 2
                elseif t <= 254 then
                    -- -1131 .. -108
                 -- stack[top] = -(t-251)*256 - tab[i+1] - 108
                 -- stack[top] = -t*256 + 251*256 - tab[i+1] - 108
                    stack[top] = -t*256 + 64148 - tab[i+1]
                    i = i + 2
                else
                    local n = 0x100 * tab[i+1] + tab[i+2]
                    if n  >= 0x8000 then
                     -- stack[top] = n - 0xFFFF - 1 + (0x100 * tab[i+3] + tab[i+4])/0xFFFF
                        stack[top] = n - 0x10000 + (0x100 * tab[i+3] + tab[i+4])/0xFFFF
                    else
                        stack[top] = n           + (0x100 * tab[i+3] + tab[i+4])/0xFFFF
                    end
                    i = i + 5
                end
            elseif t == 28 then
                -- -32768 .. +32767 : b1<<8 | b2
                top = top + 1
                local n = 0x100 * tab[i+1] + tab[i+2]
                if n  >= 0x8000 then
                 -- stack[top] = n - 0xFFFF - 1
                    stack[top] = n - 0x10000
                else
                    stack[top] = n
                end
                i = i + 3
            elseif t == 11 then -- not in cff2
                if trace_charstrings then
                    showstate("return")
                end
                return
            elseif t == 10 then
                call("local",locals,localbias) -- ,process)
                i = i + 1
            elseif t == 14 then -- not in cff2
                if width then
                    -- okay
                elseif top > 0 then
                    width = stack[1]
                    if trace_charstrings then
                        showvalue("width",width)
                    end
                else
                    width = true
                end
                if trace_charstrings then
                    showstate("endchar")
                end
                return
            elseif t == 29 then
                call("global",globals,globalbias) -- ,process)
                i = i + 1
            elseif t == 12 then
                i = i + 1
                local t = tab[i]
                local a = subactions[t]
                if a then
                    a(t)
                else
                    if trace_charstrings then
                        showvalue("<subaction>",t)
                    end
                    top = 0
                end
                i = i + 1
            elseif justpass then
                passon(t)
                i = i + 1
            else
                local a = actions[t]
                if a then
                    local s = a(t)
                    if s then
                        i = i + s + 1
                    else
                        i = i + 1
                    end
                else
                    if trace_charstrings then
                        showvalue("<action>",t)
                    end
                    top = 0
                    i = i + 1
                end
            end
        end
    end

 -- local function calculatebounds(segments,x,y)
 --     local nofsegments = #segments
 --     if nofsegments == 0 then
 --         return { x, y, x, y }
 --     else
 --         local xmin =  10000
 --         local xmax = -10000
 --         local ymin =  10000
 --         local ymax = -10000
 --         if x < xmin then xmin = x end
 --         if x > xmax then xmax = x end
 --         if y < ymin then ymin = y end
 --         if y > ymax then ymax = y end
 --         -- we now have a reasonable start so we could
 --         -- simplify the next checks
 --         for i=1,nofsegments do
 --             local s = segments[i]
 --             local x = s[1]
 --             local y = s[2]
 --             if x < xmin then xmin = x end
 --             if x > xmax then xmax = x end
 --             if y < ymin then ymin = y end
 --             if y > ymax then ymax = y end
 --             if s[#s] == "c" then -- "curveto"
 --                 local x = s[3]
 --                 local y = s[4]
 --                 if x < xmin then xmin = x elseif x > xmax then xmax = x end
 --                 if y < ymin then ymin = y elseif y > ymax then ymax = y end
 --                 local x = s[5]
 --                 local y = s[6]
 --                 if x < xmin then xmin = x elseif x > xmax then xmax = x end
 --                 if y < ymin then ymin = y elseif y > ymax then ymax = y end
 --             end
 --         end
 --         return { round(xmin), round(ymin), round(xmax), round(ymax) } -- doesn't make ceil more sense
 --     end
 -- end

    local function setbias(globals,locals)
        if version == 1 then
            return
                false,
                false
        else
            local g, l = #globals, #locals
            return
                ((g <  1240 and 107) or (g < 33900 and 1131) or 32768) + 1,
                ((l <  1240 and 107) or (l < 33900 and 1131) or 32768) + 1
        end
    end

    local function processshape(tab,index)

        tab     = bytetable(tab)

        x       = 0
        y       = 0
        width   = false
        r       = 0
        top     = 0
        stems   = 0
        result  = { } -- we could reuse it when only boundingbox calculations are needed

        xmin    = 0
        xmax    = 0
        ymin    = 0
        ymax    = 0
        checked = false

        if trace_charstrings then
            report("glyph: %i",index)
            report("data : % t",tab)
        end

        if regions then
            updateregions(vsindex)
        end

        process(tab)

        local boundingbox = {
            round(xmin),
            round(ymin),
            round(xmax),
            round(ymax),
        }

        if width == true or width == false then
            width = defaultwidth
        else
            width = nominalwidth + width
        end

        local glyph = glyphs[index] -- can be autodefined in otr
        if justpass then
            r = r + 1
            result[r] = c_endchar
            local stream = concat(result)
            if glyph then
                glyph.stream  = stream
            else
                glyphs[index] = { stream = stream }
            end
        elseif glyph then
            glyph.segments    = keepcurve ~= false and result or nil
            glyph.boundingbox = boundingbox
            if not glyph.width then
                glyph.width = width
            end
            if charset and not glyph.name then
                glyph.name = charset[index]
            end
         -- glyph.sidebearing = 0 -- todo
        elseif keepcurve then
            glyphs[index] = {
                segments    = result,
                boundingbox = boundingbox,
                width       = width,
                name        = charset and charset[index] or nil,
             -- sidebearing = 0,
            }
        else
            glyphs[index] = {
                boundingbox = boundingbox,
                width       = width,
                name        = charset and charset[index] or nil,
            }
        end

        if trace_charstrings then
            report("width      : %s",tostring(width))
            report("boundingbox: % t",boundingbox)
        end

    end

    startparsing = function(fontdata,data,streams)
        reginit  = false
        axis     = false
        regions  = data.regions
        justpass = streams == true
        if regions then
            regions = { regions } -- needs checking
            axis = data.factors or false
        end
    end

    stopparsing = function(fontdata,data)
        stack   = { }
        glyphs  = false
        result  = { }
        top     = 0
        locals  = false
        globals = false
        strings = false
    end

    local function setwidths(private)
        if not private then
            return 0, 0
        end
        local privatedata  = private.data
        if not privatedata then
            return 0, 0
        end
        return privatedata.nominalwidthx or 0, privatedata.defaultwidthx or 0
    end

    parsecharstrings = function(fontdata,data,glphs,doshapes,tversion,streams)

        local dictionary  = data.dictionaries[1]
        local charstrings = dictionary.charstrings

        keepcurve = doshapes
        version   = tversion
        strings   = data.strings
        globals   = data.routines or { }
        locals    = dictionary.subroutines or { }
        charset   = dictionary.charset
        vsindex   = dictionary.vsindex or 0
        glyphs    = glphs or { }

        globalbias,   localbias    = setbias(globals,locals)
        nominalwidth, defaultwidth = setwidths(dictionary.private)

        startparsing(fontdata,data,streams)

        for index=1,#charstrings do
            processshape(charstrings[index],index-1)
            charstrings[index] = nil -- free memory (what if used more often?)
        end

        stopparsing(fontdata,data)

        return glyphs
    end

    parsecharstring = function(fontdata,data,dictionary,tab,glphs,index,doshapes,tversion)

        keepcurve = doshapes
        version   = tversion
        strings   = data.strings
        globals   = data.routines or { }
        locals    = dictionary.subroutines or { }
        charset   = false
        vsindex   = dictionary.vsindex or 0
        glyphs    = glphs or { }

        globalbias,   localbias    = setbias(globals,locals)
        nominalwidth, defaultwidth = setwidths(dictionary.private)

        processshape(tab,index-1)

     -- return glyphs[index]
    end

end

local function readglobals(f,data)
    local routines = readlengths(f)
    for i=1,#routines do
        routines[i] = readbytetable(f,routines[i])
    end
    data.routines = routines
end

local function readencodings(f,data)
    data.encodings = { }
end

local function readcharsets(f,data,dictionary)
    local header        = data.header
    local strings       = data.strings
    local nofglyphs     = data.nofglyphs
    local charsetoffset = dictionary.charset
    if charsetoffset and charsetoffset ~= 0 then
        setposition(f,header.offset+charsetoffset)
        local format       = readbyte(f)
        local charset      = { [0] = ".notdef" }
        dictionary.charset = charset
        if format == 0 then
            for i=1,nofglyphs do
                charset[i] = strings[readushort(f)]
            end
        elseif format == 1 or format == 2 then
            local readcount = format == 1 and readbyte or readushort
            local i = 1
            while i <= nofglyphs do
                local sid = readushort(f)
                local n   = readcount(f)
                for s=sid,sid+n do
                    charset[i] = strings[s]
                    i = i + 1
                    if i > nofglyphs then
                        break
                    end
                end
            end
        else
            report("cff parser: unsupported charset format %a",format)
        end
    else
        dictionary.nocharset = true
        dictionary.charset   = nil
    end
end

local function readprivates(f,data)
    local header       = data.header
    local dictionaries = data.dictionaries
    local private      = dictionaries[1].private
    if private then
        setposition(f,header.offset+private.offset)
        private.data = readstring(f,private.size)
    end
end

local function readlocals(f,data,dictionary)
    local header  = data.header
    local private = dictionary.private
    if private then
        local subroutineoffset = private.data.subroutines
        if subroutineoffset ~= 0 then
            setposition(f,header.offset+private.offset+subroutineoffset)
            local subroutines = readlengths(f)
            for i=1,#subroutines do
                subroutines[i] = readbytetable(f,subroutines[i])
            end
            dictionary.subroutines = subroutines
            private.data.subroutines = nil
        else
            dictionary.subroutines = { }
        end
    else
        dictionary.subroutines = { }
    end
end

-- These charstrings are little programs and described in: Technical Note #5177. A truetype
-- font has only one dictionary.

local function readcharstrings(f,data,what)
    local header       = data.header
    local dictionaries = data.dictionaries
    local dictionary   = dictionaries[1]
    local stringtype   = dictionary.charstringtype
    local offset       = dictionary.charstrings
    if type(offset) ~= "number" then
        -- weird
    elseif stringtype == 2 then
        setposition(f,header.offset+offset)
        -- could be a metatable .. delayed loading
        local charstrings = readlengths(f,what=="cff2")
        local nofglyphs   = #charstrings
        for i=1,nofglyphs do
            charstrings[i] = readstring(f,charstrings[i])
        end
        data.nofglyphs         = nofglyphs
        dictionary.charstrings = charstrings
    else
        report("unsupported charstr type %i",stringtype)
        data.nofglyphs         = 0
        dictionary.charstrings = { }
    end
end

-- cid (maybe do this stepwise so less mem) -- share with above

local function readcidprivates(f,data)
    local header       = data.header
    local dictionaries = data.dictionaries[1].cid.dictionaries
    for i=1,#dictionaries do
        local dictionary = dictionaries[i]
        local private    = dictionary.private
        if private then
            setposition(f,header.offset+private.offset)
            private.data = readstring(f,private.size)
        end
    end
    parseprivates(data,dictionaries)
end

readers.parsecharstrings = parsecharstrings -- used in font-onr.lua (type 1)

local function readnoselect(f,fontdata,data,glyphs,doshapes,version,streams)
    local dictionaries = data.dictionaries
    local dictionary   = dictionaries[1]
    readglobals(f,data)
    readcharstrings(f,data,version)
    if version ~= "cff2" then
        readencodings(f,data)
        readcharsets(f,data,dictionary)
    end
    readprivates(f,data)
    parseprivates(data,data.dictionaries)
    readlocals(f,data,dictionary)
    startparsing(fontdata,data,streams)
    parsecharstrings(fontdata,data,glyphs,doshapes,version,streams)
    stopparsing(fontdata,data)
end

local function readfdselect(f,fontdata,data,glyphs,doshapes,version,streams)
    local header       = data.header
    local dictionaries = data.dictionaries
    local dictionary   = dictionaries[1]
    local cid          = dictionary.cid
    local cidselect    = cid and cid.fdselect
    readglobals(f,data)
    readcharstrings(f,data,version)
    if version ~= "cff2" then
        readencodings(f,data)
    end
    local charstrings  = dictionary.charstrings
    local fdindex      = { }
    local nofglyphs    = data.nofglyphs
    local maxindex     = -1
    setposition(f,header.offset+cidselect)
    local format       = readbyte(f)
    if format == 1 then
        for i=0,nofglyphs do -- notdef included (needs checking)
            local index = readbyte(i)
            fdindex[i] = index
            if index > maxindex then
                maxindex = index
            end
        end
    elseif format == 3 then
        local nofranges = readushort(f)
        local first     = readushort(f)
        local index     = readbyte(f)
        while true do
            local last = readushort(f)
            if index > maxindex then
                maxindex = index
            end
            for i=first,last do
                fdindex[i] = index
            end
            if last >= nofglyphs then
                break
            else
                first = last + 1
                index = readbyte(f)
            end
        end
    else
        -- unsupported format
    end
    -- hm, always
    if maxindex >= 0 then
        local cidarray = cid.fdarray
        setposition(f,header.offset+cidarray)
        local dictionaries = readlengths(f)
        for i=1,#dictionaries do
            dictionaries[i] = readstring(f,dictionaries[i])
        end
        parsedictionaries(data,dictionaries)
        cid.dictionaries = dictionaries
        readcidprivates(f,data)
        for i=1,#dictionaries do
            readlocals(f,data,dictionaries[i])
        end
        startparsing(fontdata,data,streams)
        for i=1,#charstrings do
            parsecharstring(fontdata,data,dictionaries[fdindex[i]+1],charstrings[i],glyphs,i,doshapes,version)
            charstrings[i] = nil
        end
        stopparsing(fontdata,data)
    end
end

local gotodatatable = readers.helpers.gotodatatable

local function cleanup(data,dictionaries)
 -- for i=1,#dictionaries do
 --     local d = dictionaries[i]
 --     d.subroutines = nil
 -- end
 -- data.strings = nil
 -- if data then
 --     data.charstrings  = nil
 --     data.routines     = nil
 -- end
end

function readers.cff(f,fontdata,specification)
    local tableoffset = gotodatatable(f,fontdata,"cff",specification.details)
    if tableoffset then
        local header = readheader(f)
        if header.major ~= 1 then
            report("only version %s is supported for table %a",1,"cff")
            return
        end
        local glyphs       = fontdata.glyphs
        local names        = readfontnames(f)
        local dictionaries = readtopdictionaries(f)
        local strings      = readstrings(f)
        local data = {
            header       = header,
            names        = names,
            dictionaries = dictionaries,
            strings      = strings,
            nofglyphs    = fontdata.nofglyphs,
        }
        --
        parsedictionaries(data,dictionaries,"cff")
        --
        local dic = dictionaries[1]
        local cid = dic.cid
        fontdata.cffinfo = {
            familynamename     = dic.familyname,
            fullname           = dic.fullname,
            boundingbox        = dic.boundingbox,
            weight             = dic.weight,
            italicangle        = dic.italicangle,
            underlineposition  = dic.underlineposition,
            underlinethickness = dic.underlinethickness,
            monospaced         = dic.monospaced,
        }
        fontdata.cidinfo = cid and {
            registry   = cid.registry,
            ordering   = cid.ordering,
            supplement = cid.supplement,
        }
        --
        if specification.glyphs then
            local all = specification.shapes or false
            if cid and cid.fdselect then
                readfdselect(f,fontdata,data,glyphs,all,"cff")
            else
                readnoselect(f,fontdata,data,glyphs,all,"cff")
            end
        end
        cleanup(data,dictionaries)
    end
end

function readers.cff2(f,fontdata,specification)
    local tableoffset = gotodatatable(f,fontdata,"cff2",specification.glyphs)
    if tableoffset then
        local header = readheader(f)
        if header.major ~= 2 then
            report("only version %s is supported for table %a",2,"cff2")
            return
        end
        local glyphs       = fontdata.glyphs
        local dictionaries = { readstring(f,header.dsize) }
        local data = {
            header       = header,
            dictionaries = dictionaries,
            nofglyphs    = fontdata.nofglyphs,
        }
        --
        parsedictionaries(data,dictionaries,"cff2")
        --
        local storeoffset = dictionaries[1].vstore + data.header.offset + 2 -- cff has a preceding size field
        local regions, deltas = readers.helpers.readvariationdata(f,storeoffset,factors)
        --
        data.regions  = regions
        data.deltas   = deltas
        data.factors  = specification.factors
        --
        local cid = data.dictionaries[1].cid
        local all = specification.shapes or false
        if cid and cid.fdselect then
            readfdselect(f,fontdata,data,glyphs,all,"cff2",specification.streams)
        else
            readnoselect(f,fontdata,data,glyphs,all,"cff2",specification.streams)
        end
        cleanup(data,dictionaries)
    end
end

-- temporary helper needed for checking backend patches

function readers.cffcheck(filename)
    local f = io.open(filename,"rb")
    if f then
        local fontdata = {
            glyphs = { },
        }
        local header = readheader(f)
        if header.major ~= 1 then
            report("only version %s is supported for table %a",1,"cff")
            return
        end
        local names        = readfontnames(f)
        local dictionaries = readtopdictionaries(f)
        local strings      = readstrings(f)
        local glyphs       = { }
        local data = {
            header       = header,
            names        = names,
            dictionaries = dictionaries,
            strings      = strings,
            glyphs       = glyphs,
            nofglyphs    = 4,
        }
        --
        parsedictionaries(data,dictionaries,"cff")
        --
        local cid = data.dictionaries[1].cid
        if cid and cid.fdselect then
            readfdselect(f,fontdata,data,glyphs,false)
        else
            readnoselect(f,fontdata,data,glyphs,false)
        end
        return data
    end
end