summaryrefslogtreecommitdiffstats
path: root/src/lodepng.cpp
blob: 46011a8d8eb00217cedc8eab5c6b65e52ca24e27 (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
2306
2307
2308
2309
2310
2311
2312
2313
2314
2315
2316
2317
2318
2319
2320
2321
2322
2323
2324
2325
2326
2327
2328
2329
2330
2331
2332
2333
2334
2335
2336
2337
2338
2339
2340
2341
2342
2343
2344
2345
2346
2347
2348
2349
2350
2351
2352
2353
2354
2355
2356
2357
2358
2359
2360
2361
2362
2363
2364
2365
2366
2367
2368
2369
2370
2371
2372
2373
2374
2375
2376
2377
2378
2379
2380
2381
2382
2383
2384
2385
2386
2387
2388
2389
2390
2391
2392
2393
2394
2395
2396
2397
2398
2399
2400
2401
2402
2403
2404
2405
2406
2407
2408
2409
2410
2411
2412
2413
2414
2415
2416
2417
2418
2419
2420
2421
2422
2423
2424
2425
2426
2427
2428
2429
2430
2431
2432
2433
2434
2435
2436
2437
2438
2439
2440
2441
2442
2443
2444
2445
2446
2447
2448
2449
2450
2451
2452
2453
2454
2455
2456
2457
2458
2459
2460
2461
2462
2463
2464
2465
2466
2467
2468
2469
2470
2471
2472
2473
2474
2475
2476
2477
2478
2479
2480
2481
2482
2483
2484
2485
2486
2487
2488
2489
2490
2491
2492
2493
2494
2495
2496
2497
2498
2499
2500
2501
2502
2503
2504
2505
2506
2507
2508
2509
2510
2511
2512
2513
2514
2515
2516
2517
2518
2519
2520
2521
2522
2523
2524
2525
2526
2527
2528
2529
2530
2531
2532
2533
2534
2535
2536
2537
2538
2539
2540
2541
2542
2543
2544
2545
2546
2547
2548
2549
2550
2551
2552
2553
2554
2555
2556
2557
2558
2559
2560
2561
2562
2563
2564
2565
2566
2567
2568
2569
2570
2571
2572
2573
2574
2575
2576
2577
2578
2579
2580
2581
2582
2583
2584
2585
2586
2587
2588
2589
2590
2591
2592
2593
2594
2595
2596
2597
2598
2599
2600
2601
2602
2603
2604
2605
2606
2607
2608
2609
2610
2611
2612
2613
2614
2615
2616
2617
2618
2619
2620
2621
2622
2623
2624
2625
2626
2627
2628
2629
2630
2631
2632
2633
2634
2635
2636
2637
2638
2639
2640
2641
2642
2643
2644
2645
2646
2647
2648
2649
2650
2651
2652
2653
2654
2655
2656
2657
2658
2659
2660
2661
2662
2663
2664
2665
2666
2667
2668
2669
2670
2671
2672
2673
2674
2675
2676
2677
2678
2679
2680
2681
2682
2683
2684
2685
2686
2687
2688
2689
2690
2691
2692
2693
2694
2695
2696
2697
2698
2699
2700
2701
2702
2703
2704
2705
2706
2707
2708
2709
2710
2711
2712
2713
2714
2715
2716
2717
2718
2719
2720
2721
2722
2723
2724
2725
2726
2727
2728
2729
2730
2731
2732
2733
2734
2735
2736
2737
2738
2739
2740
2741
2742
2743
2744
2745
2746
2747
2748
2749
2750
2751
2752
2753
2754
2755
2756
2757
2758
2759
2760
2761
2762
2763
2764
2765
2766
2767
2768
2769
2770
2771
2772
2773
2774
2775
2776
2777
2778
2779
2780
2781
2782
2783
2784
2785
2786
2787
2788
2789
2790
2791
2792
2793
2794
2795
2796
2797
2798
2799
2800
2801
2802
2803
2804
2805
2806
2807
2808
2809
2810
2811
2812
2813
2814
2815
2816
2817
2818
2819
2820
2821
2822
2823
2824
2825
2826
2827
2828
2829
2830
2831
2832
2833
2834
2835
2836
2837
2838
2839
2840
2841
2842
2843
2844
2845
2846
2847
2848
2849
2850
2851
2852
2853
2854
2855
2856
2857
2858
2859
2860
2861
2862
2863
2864
2865
2866
2867
2868
2869
2870
2871
2872
2873
2874
2875
2876
2877
2878
2879
2880
2881
2882
2883
2884
2885
2886
2887
2888
2889
2890
2891
2892
2893
2894
2895
2896
2897
2898
2899
2900
2901
2902
2903
2904
2905
2906
2907
2908
2909
2910
2911
2912
2913
2914
2915
2916
2917
2918
2919
2920
2921
2922
2923
2924
2925
2926
2927
2928
2929
2930
2931
2932
2933
2934
2935
2936
2937
2938
2939
2940
2941
2942
2943
2944
2945
2946
2947
2948
2949
2950
2951
2952
2953
2954
2955
2956
2957
2958
2959
2960
2961
2962
2963
2964
2965
2966
2967
2968
2969
2970
2971
2972
2973
2974
2975
2976
2977
2978
2979
2980
2981
2982
2983
2984
2985
2986
2987
2988
2989
2990
2991
2992
2993
2994
2995
2996
2997
2998
2999
3000
3001
3002
3003
3004
3005
3006
3007
3008
3009
3010
3011
3012
3013
3014
3015
3016
3017
3018
3019
3020
3021
3022
3023
3024
3025
3026
3027
3028
3029
3030
3031
3032
3033
3034
3035
3036
3037
3038
3039
3040
3041
3042
3043
3044
3045
3046
3047
3048
3049
3050
3051
3052
3053
3054
3055
3056
3057
3058
3059
3060
3061
3062
3063
3064
3065
3066
3067
3068
3069
3070
3071
3072
3073
3074
3075
3076
3077
3078
3079
3080
3081
3082
3083
3084
3085
3086
3087
3088
3089
3090
3091
3092
3093
3094
3095
3096
3097
3098
3099
3100
3101
3102
3103
3104
3105
3106
3107
3108
3109
3110
3111
3112
3113
3114
3115
3116
3117
3118
3119
3120
3121
3122
3123
3124
3125
3126
3127
3128
3129
3130
3131
3132
3133
3134
3135
3136
3137
3138
3139
3140
3141
3142
3143
3144
3145
3146
3147
3148
3149
3150
3151
3152
3153
3154
3155
3156
3157
3158
3159
3160
3161
3162
3163
3164
3165
3166
3167
3168
3169
3170
3171
3172
3173
3174
3175
3176
3177
3178
3179
3180
3181
3182
3183
3184
3185
3186
3187
3188
3189
3190
3191
3192
3193
3194
3195
3196
3197
3198
3199
3200
3201
3202
3203
3204
3205
3206
3207
3208
3209
3210
3211
3212
3213
3214
3215
3216
3217
3218
3219
3220
3221
3222
3223
3224
3225
3226
3227
3228
3229
3230
3231
3232
3233
3234
3235
3236
3237
3238
3239
3240
3241
3242
3243
3244
3245
3246
3247
3248
3249
3250
3251
3252
3253
3254
3255
3256
3257
3258
3259
3260
3261
3262
3263
3264
3265
3266
3267
3268
3269
3270
3271
3272
3273
3274
3275
3276
3277
3278
3279
3280
3281
3282
3283
3284
3285
3286
3287
3288
3289
3290
3291
3292
3293
3294
3295
3296
3297
3298
3299
3300
3301
3302
3303
3304
3305
3306
3307
3308
3309
3310
3311
3312
3313
3314
3315
3316
3317
3318
3319
3320
3321
3322
3323
3324
3325
3326
3327
3328
3329
3330
3331
3332
3333
3334
3335
3336
3337
3338
3339
3340
3341
3342
3343
3344
3345
3346
3347
3348
3349
3350
3351
3352
3353
3354
3355
3356
3357
3358
3359
3360
3361
3362
3363
3364
3365
3366
3367
3368
3369
3370
3371
3372
3373
3374
3375
3376
3377
3378
3379
3380
3381
3382
3383
3384
3385
3386
3387
3388
3389
3390
3391
3392
3393
3394
3395
3396
3397
3398
3399
3400
3401
3402
3403
3404
3405
3406
3407
3408
3409
3410
3411
3412
3413
3414
3415
3416
3417
3418
3419
3420
3421
3422
3423
3424
3425
3426
3427
3428
3429
3430
3431
3432
3433
3434
3435
3436
3437
3438
3439
3440
3441
3442
3443
3444
3445
3446
3447
3448
3449
3450
3451
3452
3453
3454
3455
3456
3457
3458
3459
3460
3461
3462
3463
3464
3465
3466
3467
3468
3469
3470
3471
3472
3473
3474
3475
3476
3477
3478
3479
3480
3481
3482
3483
3484
3485
3486
3487
3488
3489
3490
3491
3492
3493
3494
3495
3496
3497
3498
3499
3500
3501
3502
3503
3504
3505
3506
3507
3508
3509
3510
3511
3512
3513
3514
3515
3516
3517
3518
3519
3520
3521
3522
3523
3524
3525
3526
3527
3528
3529
3530
3531
3532
3533
3534
3535
3536
3537
3538
3539
3540
3541
3542
3543
3544
3545
3546
3547
3548
3549
3550
3551
3552
3553
3554
3555
3556
3557
3558
3559
3560
3561
3562
3563
3564
3565
3566
3567
3568
3569
3570
3571
3572
3573
3574
3575
3576
3577
3578
3579
3580
3581
3582
3583
3584
3585
3586
3587
3588
3589
3590
3591
3592
3593
3594
3595
3596
3597
3598
3599
3600
3601
3602
3603
3604
3605
3606
3607
3608
3609
3610
3611
3612
3613
3614
3615
3616
3617
3618
3619
3620
3621
3622
3623
3624
3625
3626
3627
3628
3629
3630
3631
3632
3633
3634
3635
3636
3637
3638
3639
3640
3641
3642
3643
3644
3645
3646
3647
3648
3649
3650
3651
3652
3653
3654
3655
3656
3657
3658
3659
3660
3661
3662
3663
3664
3665
3666
3667
3668
3669
3670
3671
3672
3673
3674
3675
3676
3677
3678
3679
3680
3681
3682
3683
3684
3685
3686
3687
3688
3689
3690
3691
3692
3693
3694
3695
3696
3697
3698
3699
3700
3701
3702
3703
3704
3705
3706
3707
3708
3709
3710
3711
3712
3713
3714
3715
3716
3717
3718
3719
3720
3721
3722
3723
3724
3725
3726
3727
3728
3729
3730
3731
3732
3733
3734
3735
3736
3737
3738
3739
3740
3741
3742
3743
3744
3745
3746
3747
3748
3749
3750
3751
3752
3753
3754
3755
3756
3757
3758
3759
3760
3761
3762
3763
3764
3765
3766
3767
3768
3769
3770
3771
3772
3773
3774
3775
3776
3777
3778
3779
3780
3781
3782
3783
3784
3785
3786
3787
3788
3789
3790
3791
3792
3793
3794
3795
3796
3797
3798
3799
3800
3801
3802
3803
3804
3805
3806
3807
3808
3809
3810
3811
3812
3813
3814
3815
3816
3817
3818
3819
3820
3821
3822
3823
3824
3825
3826
3827
3828
3829
3830
3831
3832
3833
3834
3835
3836
3837
3838
3839
3840
3841
3842
3843
3844
3845
3846
3847
3848
3849
3850
3851
3852
3853
3854
3855
3856
3857
3858
3859
3860
3861
3862
3863
3864
3865
3866
3867
3868
3869
3870
3871
3872
3873
3874
3875
3876
3877
3878
3879
3880
3881
3882
3883
3884
3885
3886
3887
3888
3889
3890
3891
3892
3893
3894
3895
3896
3897
3898
3899
3900
3901
3902
3903
3904
3905
3906
3907
3908
3909
3910
3911
3912
3913
3914
3915
3916
3917
3918
3919
3920
3921
3922
3923
3924
3925
3926
3927
3928
3929
3930
3931
3932
3933
3934
3935
3936
3937
3938
3939
3940
3941
3942
3943
3944
3945
3946
3947
3948
3949
3950
3951
3952
3953
3954
3955
3956
3957
3958
3959
3960
3961
3962
3963
3964
3965
3966
3967
3968
3969
3970
3971
3972
3973
3974
3975
3976
3977
3978
3979
3980
3981
3982
3983
3984
3985
3986
3987
3988
3989
3990
3991
3992
3993
3994
3995
3996
3997
3998
3999
4000
4001
4002
4003
4004
4005
4006
4007
4008
4009
4010
4011
4012
4013
4014
4015
4016
4017
4018
4019
4020
4021
4022
4023
4024
4025
4026
4027
4028
4029
4030
4031
4032
4033
4034
4035
4036
4037
4038
4039
4040
4041
4042
4043
4044
4045
4046
4047
4048
4049
4050
4051
4052
4053
4054
4055
4056
4057
4058
4059
4060
4061
4062
4063
4064
4065
4066
4067
4068
4069
4070
4071
4072
4073
4074
4075
4076
4077
4078
4079
4080
4081
4082
4083
4084
4085
4086
4087
4088
4089
4090
4091
4092
4093
4094
4095
4096
4097
4098
4099
4100
4101
4102
4103
4104
4105
4106
4107
4108
4109
4110
4111
4112
4113
4114
4115
4116
4117
4118
4119
4120
4121
4122
4123
4124
4125
4126
4127
4128
4129
4130
4131
4132
4133
4134
4135
4136
4137
4138
4139
4140
4141
4142
4143
4144
4145
4146
4147
4148
4149
4150
4151
4152
/*
LodePNG version 20080927

Copyright (c) 2005-2008 Lode Vandevenne

This software is provided 'as-is', without any express or implied
warranty. In no event will the authors be held liable for any damages
arising from the use of this software.

Permission is granted to anyone to use this software for any purpose,
including commercial applications, and to alter it and redistribute it
freely, subject to the following restrictions:

    1. The origin of this software must not be misrepresented; you must not
    claim that you wrote the original software. If you use this software
    in a product, an acknowledgment in the product documentation would be
    appreciated but is not required.

    2. Altered source versions must be plainly marked as such, and must not be
    misrepresented as being the original software.

    3. This notice may not be removed or altered from any source
    distribution.
*/

/*
The manual and changelog can be found in the header file "lodepng.h"
You are free to name this file lodepng.cpp or lodepng.c depending on your usage.
*/

#include "lodepng.h"
#include "portable.h"

#define USE_BRUTE_FORCE_ENCODING 1

#define VERSION_STRING "20080927"

/* ////////////////////////////////////////////////////////////////////////// */
/* / Tools For C                                                            / */
/* ////////////////////////////////////////////////////////////////////////// */

/*
About these tools (vector, uivector, ucvector and string):
-LodePNG was originally written in C++. The vectors replace the std::vectors that were used in the C++ version.
-The string tools are made to avoid problems with compilers that declare things like strncat as deprecated.
-They're not used in the interface, only internally in this file, so all their functions are made static.
*/

#ifdef LODEPNG_COMPILE_ZLIB
#ifdef LODEPNG_COMPILE_ENCODER

typedef struct vector /*this one is used only by the deflate compressor*/
{
  void* data;
  size_t size; /*in groups of bytes depending on type*/
  size_t allocsize; /*in bytes*/
  unsigned typesize; /*sizeof the type you store in data*/
} vector;

static unsigned vector_resize(vector* p, size_t size) /*returns 1 if success, 0 if failure ==> nothing done*/
{
  if(size * p->typesize > p->allocsize)
  {
    size_t newsize = size * p->typesize * 2;
    void* data = realloc(p->data, newsize);
    if(data)
    {
      p->allocsize = newsize;
      p->data = data;
      p->size = size;
    }
    else return 0;
  }
  else p->size = size;
  return 1;
}

static unsigned vector_resized(vector* p, size_t size, void dtor(void*)) /*resize and use destructor on elements if it gets smaller*/
{
  size_t i;
  if(size < p->size) for(i = size; i < p->size; i++) dtor(&((char*)(p->data))[i * p->typesize]);
  return vector_resize(p, size);
}

static void vector_cleanup(void* p)
{
  ((vector*)p)->size = ((vector*)p)->allocsize = 0;
  free(((vector*)p)->data);
  ((vector*)p)->data = NULL;
}

static void vector_cleanupd(vector* p, void dtor(void*)) /*clear and use destructor on elements*/
{
  vector_resized(p, 0, dtor);
  vector_cleanup(p);
}

static void vector_init(vector* p, unsigned typesize)
{
  p->data = NULL;
  p->size = p->allocsize = 0;
  p->typesize = typesize;
}

static void vector_swap(vector* p, vector* q) /*they're supposed to have the same typesize*/
{
  size_t tmp;
  void* tmpp;
  tmp = p->size; p->size = q->size; q->size = tmp;
  tmp = p->allocsize; p->allocsize = q->allocsize; q->allocsize = tmp;
  tmpp = p->data; p->data = q->data; q->data = tmpp;
}

static void* vector_get(vector* p, size_t index)
{
  return &((char*)p->data)[index * p->typesize];
}
#endif /*LODEPNG_COMPILE_ENCODER*/
#endif /*LODEPNG_COMPILE_ZLIB*/

/* /////////////////////////////////////////////////////////////////////////// */

#ifdef LODEPNG_COMPILE_ZLIB
typedef struct uivector
{
  unsigned* data;
  size_t size; /*size in number of unsigned longs*/
  size_t allocsize; /*allocated size in bytes*/
} uivector;

static void uivector_cleanup(void* p)
{
  ((uivector*)p)->size = ((uivector*)p)->allocsize = 0;
  free(((uivector*)p)->data);
  ((uivector*)p)->data = NULL;
}

static unsigned uivector_resize(uivector* p, size_t size) /*returns 1 if success, 0 if failure ==> nothing done*/
{
  if(size * sizeof(unsigned) > p->allocsize)
  {
    size_t newsize = size * sizeof(unsigned) * 2;
    void* data = realloc(p->data, newsize);
    if(data)
    {
      p->allocsize = newsize;
      p->data = (unsigned*)data;
      p->size = size;
    }
    else return 0;
  }
  else p->size = size;
  return 1;
}

static unsigned uivector_resizev(uivector* p, size_t size, unsigned value) /*resize and give all new elements the value*/
{
  size_t oldsize = p->size, i;
  if(!uivector_resize(p, size)) return 0;
  for(i = oldsize; i < size; i++) p->data[i] = value;
  return 1;
}

static void uivector_init(uivector* p)
{
  p->data = NULL;
  p->size = p->allocsize = 0;
}

#ifdef LODEPNG_COMPILE_ENCODER
static unsigned uivector_push_back(uivector* p, unsigned c) /*returns 1 if success, 0 if failure ==> nothing done*/
{
  if(!uivector_resize(p, p->size + 1)) return 0;
  p->data[p->size - 1] = c;
  return 1;
}

static unsigned uivector_copy(uivector* p, const uivector* q) /*copy q to p, returns 1 if success, 0 if failure ==> nothing done*/
{
  size_t i;
  if(!uivector_resize(p, q->size)) return 0;
  for(i = 0; i < q->size; i++) p->data[i] = q->data[i];
  return 1;
}

static void uivector_swap(uivector* p, uivector* q)
{
  size_t tmp;
  unsigned* tmpp;
  tmp = p->size; p->size = q->size; q->size = tmp;
  tmp = p->allocsize; p->allocsize = q->allocsize; q->allocsize = tmp;
  tmpp = p->data; p->data = q->data; q->data = tmpp;
}
#endif /*LODEPNG_COMPILE_ENCODER*/
#endif /*LODEPNG_COMPILE_ZLIB*/

/* /////////////////////////////////////////////////////////////////////////// */

typedef struct ucvector
{
  unsigned char* data;
  size_t size; /*used size*/
  size_t allocsize; /*allocated size*/
} ucvector;

static void ucvector_cleanup(void* p)
{
  ((ucvector*)p)->size = ((ucvector*)p)->allocsize = 0;
  free(((ucvector*)p)->data);
  ((ucvector*)p)->data = NULL;
}

static unsigned ucvector_resize(ucvector* p, size_t size) /*returns 1 if success, 0 if failure ==> nothing done*/
{
  if(size * sizeof(unsigned) > p->allocsize)
  {
    size_t newsize = size * sizeof(unsigned) * 2;
    void* data = realloc(p->data, newsize);
    if(data)
    {
      p->allocsize = newsize;
      p->data = (unsigned char*)data;
      p->size = size;
    }
    else return 0; /*error: not enough memory*/
  }
  else p->size = size;
  return 1;
}

#ifdef LODEPNG_COMPILE_DECODER
#ifdef LODEPNG_COMPILE_PNG
static unsigned ucvector_resizev(ucvector* p, size_t size, unsigned char value) /*resize and give all new elements the value*/
{
  size_t oldsize = p->size, i;
  if(!ucvector_resize(p, size)) return 0;
  for(i = oldsize; i < size; i++) p->data[i] = value;
  return 1;
}
#endif /*LODEPNG_COMPILE_PNG*/
#endif /*LODEPNG_COMPILE_DECODER*/

static void ucvector_init(ucvector* p)
{
  p->data = NULL;
  p->size = p->allocsize = 0;
}

#ifdef LODEPNG_COMPILE_ZLIB
/*you can both convert from vector to buffer&size and vica versa*/
static void ucvector_init_buffer(ucvector* p, unsigned char* buffer, size_t size)
{
  p->data = buffer;
  p->allocsize = p->size = size;
}
#endif /*LODEPNG_COMPILE_ZLIB*/

static unsigned ucvector_push_back(ucvector* p, unsigned char c) /*returns 1 if success, 0 if failure ==> nothing done*/
{
  if(!ucvector_resize(p, p->size + 1)) return 0;
  p->data[p->size - 1] = c;
  return 1;
}

/* /////////////////////////////////////////////////////////////////////////// */

#ifdef LODEPNG_COMPILE_PNG
#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS
static unsigned string_resize(char** out, size_t size) /*returns 1 if success, 0 if failure ==> nothing done*/
{
  char* data = (char*)realloc(*out, size + 1);
  if(data)
  {
    data[size] = 0; /*null termination char*/
    *out = data;
  }
  return data != 0;
}

static void string_init(char** out) /*init a {char*, size_t} pair for use as string*/
{
  *out = NULL;
  string_resize(out, 0);
}

static void string_cleanup(char** out) /*free the above pair again*/
{
  free(*out);
  *out = NULL;
}

static void string_set(char** out, const char* in)
{
  size_t insize = strlen(in), i = 0;
  if(string_resize(out, insize)) for(i = 0; i < insize; i++) (*out)[i] = in[i];
}
#endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/
#endif /*LODEPNG_COMPILE_PNG*/

#ifdef LODEPNG_COMPILE_ZLIB

/* ////////////////////////////////////////////////////////////////////////// */
/* / Reading and writing single bits and bytes from/to stream for Deflate   / */
/* ////////////////////////////////////////////////////////////////////////// */

#ifdef LODEPNG_COMPILE_ENCODER
static void addBitToStream(size_t* bitpointer, ucvector* bitstream, unsigned char bit)
{
  if((*bitpointer) % 8 == 0) ucvector_push_back(bitstream, 0); /*add a new byte at the end*/
  (bitstream->data[bitstream->size - 1]) |= (bit << ((*bitpointer) & 0x7)); /*earlier bit of huffman code is in a lesser significant bit of an earlier byte*/
  (*bitpointer)++;
}

static void addBitsToStream(size_t* bitpointer, ucvector* bitstream, unsigned value, size_t nbits)
{
  size_t i;
  for(i = 0; i < nbits; i++) addBitToStream(bitpointer, bitstream, (unsigned char)((value >> i) & 1));
}

static void addBitsToStreamReversed(size_t* bitpointer, ucvector* bitstream, unsigned value, size_t nbits)
{
  size_t i;
  for(i = 0; i < nbits; i++) addBitToStream(bitpointer, bitstream, (unsigned char)((value >> (nbits - 1 - i)) & 1));
}
#endif /*LODEPNG_COMPILE_ENCODER*/

#ifdef LODEPNG_COMPILE_DECODER
static unsigned char readBitFromStream(size_t* bitpointer, const unsigned char* bitstream)
{
  unsigned char result = (unsigned char)((bitstream[(*bitpointer) >> 3] >> ((*bitpointer) & 0x7)) & 1);
  (*bitpointer)++;
  return result;
}

static unsigned readBitsFromStream(size_t* bitpointer, const unsigned char* bitstream, size_t nbits)
{
  unsigned result = 0, i;
  for(i = 0; i < nbits; i++) result += ((unsigned)readBitFromStream(bitpointer, bitstream)) << i;
  return result;
}
#endif /*LODEPNG_COMPILE_DECODER*/

/* ////////////////////////////////////////////////////////////////////////// */
/* / Deflate - Huffman                                                      / */
/* ////////////////////////////////////////////////////////////////////////// */

#define FIRST_LENGTH_CODE_INDEX 257
#define LAST_LENGTH_CODE_INDEX 285
#define NUM_DEFLATE_CODE_SYMBOLS 288 /*256 literals, the end code, some length codes, and 2 unused codes*/
#define NUM_DISTANCE_SYMBOLS 32 /*the distance codes have their own symbols, 30 used, 2 unused*/
#define NUM_CODE_LENGTH_CODES 19 /*the code length codes. 0-15: code lengths, 16: copy previous 3-6 times, 17: 3-10 zeros, 18: 11-138 zeros*/

static const unsigned LENGTHBASE[29] /*the base lengths represented by codes 257-285*/
  = {3, 4, 5, 6, 7, 8, 9, 10, 11, 13, 15, 17, 19, 23, 27, 31, 35, 43, 51, 59, 67, 83, 99, 115, 131, 163, 195, 227, 258};
static const unsigned LENGTHEXTRA[29] /*the extra bits used by codes 257-285 (added to base length)*/
  = {0, 0, 0, 0, 0, 0, 0,  0,  1,  1,  1,  1,  2,  2,  2,  2,  3,  3,  3,  3,  4,  4,  4,   4,   5,   5,   5,   5,   0};
static const unsigned DISTANCEBASE[30] /*the base backwards distances (the bits of distance codes appear after length codes and use their own huffman tree)*/
  = {1, 2, 3, 4, 5, 7, 9, 13, 17, 25, 33, 49, 65, 97, 129, 193, 257, 385, 513, 769, 1025, 1537, 2049, 3073, 4097, 6145, 8193, 12289, 16385, 24577};
static const unsigned DISTANCEEXTRA[30] /*the extra bits of backwards distances (added to base)*/
  = {0, 0, 0, 0, 1, 1, 2,  2,  3,  3,  4,  4,  5,  5,   6,   6,   7,   7,   8,   8,    9,    9,   10,   10,   11,   11,   12,    12,    13,    13};
static const unsigned CLCL[NUM_CODE_LENGTH_CODES] /*the order in which "code length alphabet code lengths" are stored, out of this the huffman tree of the dynamic huffman tree lengths is generated*/
  = {16, 17, 18, 0, 8, 7, 9, 6, 10, 5, 11, 4, 12, 3, 13, 2, 14, 1, 15};

/* /////////////////////////////////////////////////////////////////////////// */

#ifdef LODEPNG_COMPILE_ENCODER
/*terminology used for the package-merge algorithm and the coin collector's problem*/
typedef struct Coin /*a coin can be multiple coins (when they're merged)*/
{
  uivector symbols;
  float weight; /*the sum of all weights in this coin*/
} Coin;

static void Coin_init(Coin* c)
{
  uivector_init(&c->symbols);
}

static void Coin_cleanup(void* c) /*void* so that this dtor can be given as function pointer to the vector resize function*/
{
  uivector_cleanup(&((Coin*)c)->symbols);
}

static void Coin_copy(Coin* c1, const Coin* c2)
{
  c1->weight = c2->weight;
  uivector_copy(&c1->symbols, &c2->symbols);
}

static void addCoins(Coin* c1, const Coin* c2)
{
  unsigned i;
  for(i = 0; i < c2->symbols.size; i++) uivector_push_back(&c1->symbols, c2->symbols.data[i]);
  c1->weight += c2->weight;
}

static void Coin_sort(Coin* data, size_t amount) /*combsort*/
{
  size_t gap = amount;
  unsigned char swapped = 0;
  while(gap > 1 || swapped)
  {
    size_t i;
    gap = (gap * 10) / 13; /*shrink factor 1.3*/
    if(gap == 9 || gap == 10) gap = 11; /*combsort11*/
    if(gap < 1) gap = 1;
    swapped = 0;
    for(i = 0; i < amount - gap; i++)
    {
      size_t j = i + gap;
      if(data[j].weight < data[i].weight)
      {
        float temp = data[j].weight; data[j].weight = data[i].weight; data[i].weight = temp;
        uivector_swap(&data[i].symbols, &data[j].symbols);
        swapped = 1;
      }
    }
  }
}
#endif /*LODEPNG_COMPILE_ENCODER*/

typedef struct HuffmanTree
{
  uivector tree2d;
  uivector tree1d;
  uivector lengths; /*the lengths of the codes of the 1d-tree*/
  unsigned maxbitlen; /*maximum number of bits a single code can get*/
  unsigned numcodes; /*number of symbols in the alphabet = number of codes*/
} HuffmanTree;

/*function used for debug purposes*/
/*#include <iostream>
static void HuffmanTree_draw(HuffmanTree* tree)
{
  std::cout << "tree. length: " << tree->numcodes << " maxbitlen: " << tree->maxbitlen << std::endl;
  for(size_t i = 0; i < tree->tree1d.size; i++)
  {
    if(tree->lengths.data[i])
      std::cout << i << " " << tree->tree1d.data[i] << " " << tree->lengths.data[i] << std::endl;
  }
  std::cout << std::endl;
}*/

static void HuffmanTree_init(HuffmanTree* tree)
{
  uivector_init(&tree->tree2d);
  uivector_init(&tree->tree1d);
  uivector_init(&tree->lengths);
}

static void HuffmanTree_cleanup(HuffmanTree* tree)
{
  uivector_cleanup(&tree->tree2d);
  uivector_cleanup(&tree->tree1d);
  uivector_cleanup(&tree->lengths);
}

/*the tree representation used by the decoder. return value is error*/
static unsigned HuffmanTree_make2DTree(HuffmanTree* tree)
{
  unsigned nodefilled = 0; /*up to which node it is filled*/
  unsigned treepos = 0; /*position in the tree (1 of the numcodes columns)*/
  unsigned n, i;
  
  if(!uivector_resize(&tree->tree2d, tree->numcodes * 2)) return 9901; /*if failed return not enough memory error*/
  /*convert tree1d[] to tree2d[][]. In the 2D array, a value of 32767 means uninited, a value >= numcodes is an address to another bit, a value < numcodes is a code. The 2 rows are the 2 possible bit values (0 or 1), there are as many columns as codes - 1
  a good huffmann tree has N * 2 - 1 nodes, of which N - 1 are internal nodes. Here, the internal nodes are stored (what their 0 and 1 option point to). There is only memory for such good tree currently, if there are more nodes (due to too long length codes), error 55 will happen*/
  for(n = 0;  n < tree->numcodes * 2; n++) tree->tree2d.data[n] = 32767; /*32767 here means the tree2d isn't filled there yet*/

  for(n = 0; n < tree->numcodes; n++) /*the codes*/
  for(i = 0; i < tree->lengths.data[n]; i++) /*the bits for this code*/
  {
    unsigned char bit = (unsigned char)((tree->tree1d.data[n] >> (tree->lengths.data[n] - i - 1)) & 1);
    if(treepos > tree->numcodes - 2) return 55; /*error 55: oversubscribed; see description in header*/
    if(tree->tree2d.data[2 * treepos + bit] == 32767) /*not yet filled in*/
    {
      if(i + 1 == tree->lengths.data[n]) /*last bit*/
      {
        tree->tree2d.data[2 * treepos + bit] = n; /*put the current code in it*/
        treepos = 0;
      }
      else /*put address of the next step in here, first that address has to be found of course (it's just nodefilled + 1)...*/
      {
        nodefilled++;
        tree->tree2d.data[2 * treepos + bit] = nodefilled + tree->numcodes; /*addresses encoded with numcodes added to it*/
        treepos = nodefilled;
      }
    }
    else treepos = tree->tree2d.data[2 * treepos + bit] - tree->numcodes;
  }
  for(n = 0;  n < tree->numcodes * 2; n++) if(tree->tree2d.data[n] == 32767) tree->tree2d.data[n] = 0; /*remove possible remaining 32767's*/
  
  return 0;
}

static unsigned HuffmanTree_makeFromLengths2(HuffmanTree* tree) /*given that numcodes, lengths and maxbitlen are already filled in correctly. return value is error.*/
{
  uivector blcount;
  uivector nextcode;
  unsigned bits, n, error = 0;
  
  uivector_init(&blcount);
  uivector_init(&nextcode);
  if(!uivector_resize(&tree->tree1d, tree->numcodes)
  || !uivector_resizev(&blcount, tree->maxbitlen + 1, 0)
  || !uivector_resizev(&nextcode, tree->maxbitlen + 1, 0))
    error = 9902;
  
  if(!error)
  {
    /*step 1: count number of instances of each code length*/
    for(bits = 0; bits < tree->numcodes; bits++) blcount.data[tree->lengths.data[bits]]++;
    /*step 2: generate the nextcode values*/
    for(bits = 1; bits <= tree->maxbitlen; bits++) nextcode.data[bits] = (nextcode.data[bits - 1] + blcount.data[bits - 1]) << 1;
    /*step 3: generate all the codes*/
    for(n = 0; n < tree->numcodes; n++) if(tree->lengths.data[n] != 0) tree->tree1d.data[n] = nextcode.data[tree->lengths.data[n]]++;
  }
   
  uivector_cleanup(&blcount);
  uivector_cleanup(&nextcode);
  
  if(!error) return HuffmanTree_make2DTree(tree);
  else return error;
}

/*given the code lengths (as stored in the PNG file), generate the tree as defined by Deflate. maxbitlen is the maximum bits that a code in the tree can have. return value is error.*/
static unsigned HuffmanTree_makeFromLengths(HuffmanTree* tree, const unsigned* bitlen, size_t numcodes, unsigned maxbitlen)
{
  unsigned i;
  if(!uivector_resize(&tree->lengths, numcodes)) return 9903;
  for(i = 0; i < numcodes; i++) tree->lengths.data[i] = bitlen[i];
  tree->numcodes = (unsigned)numcodes; /*number of symbols*/
  tree->maxbitlen = maxbitlen;
  return HuffmanTree_makeFromLengths2(tree);
}

#ifdef LODEPNG_COMPILE_ENCODER
static unsigned HuffmanTree_fillInCoins(vector* coins, const unsigned* frequencies, unsigned numcodes, size_t sum)
{
  unsigned i;
  for(i = 0; i < numcodes; i++)
  {
    Coin* coin;
    if(frequencies[i] == 0) continue; /*it's important to exclude symbols that aren't present*/
    if(!vector_resize(coins, coins->size + 1)) { vector_cleanup(coins); return 9904; }
    coin = (Coin*)(vector_get(coins, coins->size - 1));
    Coin_init(coin);
    coin->weight = frequencies[i] / (float)sum;
    uivector_push_back(&coin->symbols, i);
  }
  if(coins->size) Coin_sort((Coin*)coins->data, coins->size);
  return 0;
}

static unsigned HuffmanTree_makeFromFrequencies(HuffmanTree* tree, const unsigned* frequencies, size_t numcodes, unsigned maxbitlen)
{
  unsigned i, j;
  size_t sum = 0, numpresent = 0;
  unsigned error = 0;
  
  vector prev_row; /*type Coin, the previous row of coins*/
  vector coins; /*type Coin, the coins of the currently calculated row*/
  
  tree->maxbitlen = maxbitlen;
  
  for(i = 0; i < numcodes; i++)
  {
    if(frequencies[i] > 0)
    {
      numpresent++;
      sum += frequencies[i];
    }
  }
  
  if(numcodes == 0) return 80; /*error: a tree of 0 symbols is not supposed to be made*/
  tree->numcodes = (unsigned)numcodes; /*number of symbols*/
  uivector_resize(&tree->lengths, 0);
  if(!uivector_resizev(&tree->lengths, tree->numcodes, 0)) return 9905;
  
  if(numpresent == 0) /*there are no symbols at all, in that case add one symbol of value 0 to the tree (see RFC 1951 section 3.2.7) */
  {
    tree->lengths.data[0] = 1;
    return HuffmanTree_makeFromLengths2(tree);
  }
  else if(numpresent == 1) /*the package merge algorithm gives wrong results if there's only one symbol (theoretically 0 bits would then suffice, but we need a proper symbol for zlib)*/
  {
    for(i = 0; i < numcodes; i++) if(frequencies[i]) tree->lengths.data[i] = 1;
    return HuffmanTree_makeFromLengths2(tree);
  }
  
  vector_init(&coins, sizeof(Coin));
  vector_init(&prev_row, sizeof(Coin));

  /*Package-Merge algorithm represented by coin collector's problem
  For every symbol, maxbitlen coins will be created*/
  
  /*first row, lowest denominator*/
  error = HuffmanTree_fillInCoins(&coins, frequencies, tree->numcodes, sum);
  if(!error)
  {
    for(j = 1; j <= maxbitlen && !error; j++) /*each of the remaining rows*/
    {
      vector_swap(&coins, &prev_row); /*swap instead of copying*/
      if(!vector_resized(&coins, 0, Coin_cleanup)) { error = 9906; break; }

      for(i = 0; i + 1 < prev_row.size; i += 2)
      {
        if(!vector_resize(&coins, coins.size + 1)) { error = 9907; break; }
        Coin_init((Coin*)vector_get(&coins, coins.size - 1));
        Coin_copy((Coin*)vector_get(&coins, coins.size - 1), (Coin*)vector_get(&prev_row, i));
        addCoins((Coin*)vector_get(&coins, coins.size - 1), (Coin*)vector_get(&prev_row, i + 1)); /*merge the coins into packages*/
      }
      if(j < maxbitlen)
      {
        error = HuffmanTree_fillInCoins(&coins, frequencies, tree->numcodes, sum);
      }
    }
  }
  
  if(!error)
  {
    /*keep the coins with lowest weight, so that they add up to the amount of symbols - 1*/
    vector_resized(&coins, numpresent - 1, Coin_cleanup);
    
    /*calculate the lenghts of each symbol, as the amount of times a coin of each symbol is used*/
    for(i = 0; i < coins.size; i++)
    {
      Coin* coin = (Coin*)vector_get(&coins, i);
      for(j = 0; j < coin->symbols.size; j++) tree->lengths.data[coin->symbols.data[j]]++;
    }
    
    error = HuffmanTree_makeFromLengths2(tree);
  }

  vector_cleanupd(&coins, Coin_cleanup);
  vector_cleanupd(&prev_row, Coin_cleanup);
  
  return error;
}

static unsigned HuffmanTree_getCode(const HuffmanTree* tree, unsigned index) { return tree->tree1d.data[index]; }
static unsigned HuffmanTree_getLength(const HuffmanTree* tree, unsigned index) { return tree->lengths.data[index]; }
#endif /*LODEPNG_COMPILE_ENCODER*/

/*get the tree of a deflated block with fixed tree, as specified in the deflate specification*/
static unsigned generateFixedTree(HuffmanTree* tree)
{
  unsigned i, error = 0;
  uivector bitlen;
  uivector_init(&bitlen);
  if(!uivector_resize(&bitlen, NUM_DEFLATE_CODE_SYMBOLS)) error = 9909;
  
  if(!error)
  {
    /*288 possible codes: 0-255=literals, 256=endcode, 257-285=lengthcodes, 286-287=unused*/
    for(i =   0; i <= 143; i++) bitlen.data[i] = 8;
    for(i = 144; i <= 255; i++) bitlen.data[i] = 9;
    for(i = 256; i <= 279; i++) bitlen.data[i] = 7;
    for(i = 280; i <= 287; i++) bitlen.data[i] = 8;
    
    error = HuffmanTree_makeFromLengths(tree, bitlen.data, NUM_DEFLATE_CODE_SYMBOLS, 15);
  }
  
  uivector_cleanup(&bitlen);
  return error;
}

static unsigned generateDistanceTree(HuffmanTree* tree)
{
  unsigned i, error = 0;
  uivector bitlen;
  uivector_init(&bitlen);
  if(!uivector_resize(&bitlen, NUM_DISTANCE_SYMBOLS)) error = 9910;
  
  /*there are 32 distance codes, but 30-31 are unused*/
  if(!error)
  {
    for(i = 0; i < NUM_DISTANCE_SYMBOLS; i++) bitlen.data[i] = 5;
    error = HuffmanTree_makeFromLengths(tree, bitlen.data, NUM_DISTANCE_SYMBOLS, 15);
  }
  uivector_cleanup(&bitlen);
  return error;
}

#ifdef LODEPNG_COMPILE_DECODER
/*Decodes a symbol from the tree
if decoded is true, then result contains the symbol, otherwise it contains something unspecified (because the symbol isn't fully decoded yet)
bit is the bit that was just read from the stream
you have to decode a full symbol (let the decode function return true) before you can try to decode another one, otherwise the state isn't reset
return value is error.*/
static unsigned HuffmanTree_decode(const HuffmanTree* tree, unsigned* decoded, unsigned* result, unsigned* treepos, unsigned char bit)
{
  if((*treepos) >= tree->numcodes) return 11; /*error: it appeared outside the codetree*/
  
  (*result) = tree->tree2d.data[2 * (*treepos) + bit];
  (*decoded) = ((*result) < tree->numcodes);

  if(*decoded) (*treepos) = 0;
  else (*treepos) = (*result) - tree->numcodes;
  
  return 0;
}

static unsigned huffmanDecodeSymbol(unsigned int* error, const unsigned char* in, size_t* bp, const HuffmanTree* codetree, size_t inlength)
{
  unsigned treepos = 0, decoded, ct;
  for(;;)
  {
    unsigned char bit;
    if(((*bp) & 0x07) == 0 && ((*bp) >> 3) > inlength) { *error = 10; return 0; } /*error: end of input memory reached without endcode*/
    bit = readBitFromStream(bp, in);
    *error = HuffmanTree_decode(codetree, &decoded, &ct, &treepos, bit);
    if(*error) return 0; /*stop, an error happened*/
    if(decoded) return ct;
  }
}
#endif /*LODEPNG_COMPILE_DECODER*/

#ifdef LODEPNG_COMPILE_DECODER

/* ////////////////////////////////////////////////////////////////////////// */
/* / Inflator                                                               / */
/* ////////////////////////////////////////////////////////////////////////// */

/*get the tree of a deflated block with fixed tree, as specified in the deflate specification*/
static void getTreeInflateFixed(HuffmanTree* tree, HuffmanTree* treeD)
{
  /*error checking not done, this is fixed stuff, it works, it doesn't depend on the image*/
  generateFixedTree(tree);
  generateDistanceTree(treeD);
}

/*get the tree of a deflated block with dynamic tree, the tree itself is also Huffman compressed with a known tree*/
static unsigned getTreeInflateDynamic(HuffmanTree* codetree, HuffmanTree* codetreeD, HuffmanTree* codelengthcodetree,
                                      const unsigned char* in, size_t* bp, size_t inlength)
{
  /*make sure that length values that aren't filled in will be 0, or a wrong tree will be generated*/
  /*C-code note: use no "return" between ctor and dtor of an uivector!*/
  unsigned error = 0;
  unsigned n, HLIT, HDIST, HCLEN, i;
  uivector bitlen;
  uivector bitlenD;
  uivector codelengthcode;
  
  if((*bp) >> 3 >= inlength - 2) { return 49; } /*the bit pointer is or will go past the memory*/

  HLIT =  readBitsFromStream(bp, in, 5) + 257; /*number of literal/length codes + 257. Unlike the spec, the value 257 is added to it here already*/
  HDIST = readBitsFromStream(bp, in, 5) + 1; /*number of distance codes. Unlike the spec, the value 1 is added to it here already*/
  HCLEN = readBitsFromStream(bp, in, 4) + 4; /*number of code length codes. Unlike the spec, the value 4 is added to it here already*/
  
  /*read the code length codes out of 3 * (amount of code length codes) bits*/
  uivector_init(&codelengthcode);
  if(!uivector_resize(&codelengthcode, NUM_CODE_LENGTH_CODES)) error = 9911;
  
  if(!error)
  {
    for(i = 0; i < NUM_CODE_LENGTH_CODES; i++)
    {
      if(i < HCLEN) codelengthcode.data[CLCL[i]] = readBitsFromStream(bp, in, 3);
      else codelengthcode.data[CLCL[i]] = 0; /*if not, it must stay 0*/
    }
    
    error = HuffmanTree_makeFromLengths(codelengthcodetree, codelengthcode.data, codelengthcode.size, 7);
  }

  uivector_cleanup(&codelengthcode);
  if(error) return error;
  
  /*now we can use this tree to read the lengths for the tree that this function will return*/
  uivector_init(&bitlen);
  uivector_resizev(&bitlen, NUM_DEFLATE_CODE_SYMBOLS, 0);
  uivector_init(&bitlenD);
  uivector_resizev(&bitlenD, NUM_DISTANCE_SYMBOLS, 0);
  i = 0;
  if(!bitlen.data || !bitlenD.data) error = 9912;
  else while(i < HLIT + HDIST) /*i is the current symbol we're reading in the part that contains the code lengths of lit/len codes and dist codes*/
  {
    unsigned code = huffmanDecodeSymbol(&error, in, bp, codelengthcodetree, inlength);
    if(error) break;
    
    if(code <= 15) /*a length code*/
    {
      if(i < HLIT) bitlen.data[i] = code;
      else bitlenD.data[i - HLIT] = code;
      i++;
    }
    else if(code == 16) /*repeat previous*/
    {
      unsigned replength = 3; /*read in the 2 bits that indicate repeat length (3-6)*/
      unsigned value; /*set value to the previous code*/
      
      if((*bp) >> 3 >= inlength) { error = 50; break; } /*error, bit pointer jumps past memory*/
      
      replength += readBitsFromStream(bp, in, 2);
      
      if((i - 1) < HLIT) value = bitlen.data[i - 1];
      else value = bitlenD.data[i - HLIT - 1];
      /*repeat this value in the next lengths*/
      for(n = 0; n < replength; n++)
      {
        if(i >= HLIT + HDIST) { error = 13; break; } /*error: i is larger than the amount of codes*/
        if(i < HLIT) bitlen.data[i] = value;
        else bitlenD.data[i - HLIT] = value;
        i++;
      }
    }
    else if(code == 17) /*repeat "0" 3-10 times*/
    {
      unsigned replength = 3; /*read in the bits that indicate repeat length*/
      if((*bp) >> 3 >= inlength) { error = 50; break; } /*error, bit pointer jumps past memory*/

      replength += readBitsFromStream(bp, in, 3);
      
      /*repeat this value in the next lengths*/
      for(n = 0; n < replength; n++)
      {
        if(i >= HLIT + HDIST) { error = 14; break; } /*error: i is larger than the amount of codes*/
        if(i < HLIT) bitlen.data[i] = 0;
        else bitlenD.data[i - HLIT] = 0;
        i++;
      }
    }
    else if(code == 18) /*repeat "0" 11-138 times*/
    {
      unsigned replength = 11; /*read in the bits that indicate repeat length*/
      if((*bp) >> 3 >= inlength) { error = 50; break; } /*error, bit pointer jumps past memory*/
      replength += readBitsFromStream(bp, in, 7);
      
      /*repeat this value in the next lengths*/
      for(n = 0; n < replength; n++)
      {
        if(i >= HLIT + HDIST) { error = 15; break; } /*error: i is larger than the amount of codes*/
        if(i < HLIT) bitlen.data[i] = 0;
        else bitlenD.data[i - HLIT] = 0;
        i++;
      }
    }
    else { error = 16; break; } /*error: somehow an unexisting code appeared. This can never happen.*/
  }
  
  if(!error && bitlen.data[256] == 0) { error = 64; } /*the length of the end code 256 must be larger than 0*/
  
  /*now we've finally got HLIT and HDIST, so generate the code trees, and the function is done*/
  if(!error) error = HuffmanTree_makeFromLengths(codetree, &bitlen.data[0], bitlen.size, 15);
  if(!error) error = HuffmanTree_makeFromLengths(codetreeD, &bitlenD.data[0], bitlenD.size, 15);
  
  uivector_cleanup(&bitlen);
  uivector_cleanup(&bitlenD);
  
  return error;
}

/*inflate a block with dynamic of fixed Huffman tree*/
static unsigned inflateHuffmanBlock(ucvector* out, const unsigned char* in, size_t* bp, size_t* pos, size_t inlength, unsigned btype)
{
  unsigned endreached = 0, error = 0;
  HuffmanTree codetree; /*287, the code tree for Huffman codes*/
  HuffmanTree codetreeD; /*31, the code tree for distance codes*/
  
  HuffmanTree_init(&codetree);
  HuffmanTree_init(&codetreeD);
  
  if(btype == 1) getTreeInflateFixed(&codetree, &codetreeD);
  else if(btype == 2)
  {
    HuffmanTree codelengthcodetree; /*18, the code tree for code length codes*/
    HuffmanTree_init(&codelengthcodetree);
    error = getTreeInflateDynamic(&codetree, &codetreeD, &codelengthcodetree, in, bp, inlength);
    HuffmanTree_cleanup(&codelengthcodetree);
  }
  
  while(!endreached && !error)
  {
    unsigned code = huffmanDecodeSymbol(&error, in, bp, &codetree, inlength);
    if(error) break; /*some error happened in the above function*/
    if(code == 256) endreached = 1; /*end code*/
    else if(code <= 255) /*literal symbol*/
    {
      if((*pos) >= out->size) ucvector_resize(out, ((*pos) + 1) * 2); /*reserve more room at once*/
      if((*pos) >= out->size) { error = 9913; break; } /*not enough memory*/
      out->data[(*pos)] = (unsigned char)(code);
      (*pos)++;
    }
    else if(code >= FIRST_LENGTH_CODE_INDEX && code <= LAST_LENGTH_CODE_INDEX) /*length code*/
    {
      /*part 1: get length base*/
      size_t length = LENGTHBASE[code - FIRST_LENGTH_CODE_INDEX];
      unsigned codeD, distance, numextrabitsD;
      size_t start, forward, backward, numextrabits;
      
      /*part 2: get extra bits and add the value of that to length*/
      numextrabits = LENGTHEXTRA[code - FIRST_LENGTH_CODE_INDEX];
      if(((*bp) >> 3) >= inlength) { error = 51; break; } /*error, bit pointer will jump past memory*/
      length += readBitsFromStream(bp, in, numextrabits);
      
      /*part 3: get distance code*/
      codeD = huffmanDecodeSymbol(&error, in, bp, &codetreeD, inlength);
      if(error) break;
      if(codeD > 29) { error = 18; break; } /*error: invalid distance code (30-31 are never used)*/
      distance = DISTANCEBASE[codeD];
      
      /*part 4: get extra bits from distance*/
      numextrabitsD = DISTANCEEXTRA[codeD];
      if(((*bp) >> 3) >= inlength) { error = 51; break; } /*error, bit pointer will jump past memory*/
      distance += readBitsFromStream(bp, in, numextrabitsD);
      
      /*part 5: fill in all the out[n] values based on the length and dist*/
      start = (*pos);
      backward = start - distance;
      if((*pos) + length >= out->size) ucvector_resize(out, ((*pos) + length) * 2); /*reserve more room at once*/
      if((*pos) + length >= out->size) { error = 9914; break; } /*not enough memory*/
      
      for(forward = 0; forward < length; forward++)
      {
        out->data[(*pos)] = out->data[backward];
        (*pos)++;
        backward++;
        if(backward >= start) backward = start - distance;
      }
    }
  }
  
  HuffmanTree_cleanup(&codetree);
  HuffmanTree_cleanup(&codetreeD);
  
  return error;
}

static unsigned inflateNoCompression(ucvector* out, const unsigned char* in, size_t* bp, size_t* pos, size_t inlength)
{
  /*go to first boundary of byte*/
  size_t p;
  unsigned LEN, NLEN, n, error = 0;
  while(((*bp) & 0x7) != 0) (*bp)++;
  p = (*bp) / 8; /*byte position*/
  
  /*read LEN (2 bytes) and NLEN (2 bytes)*/
  if(p >= inlength - 4) return 52; /*error, bit pointer will jump past memory*/
  LEN = in[p] + 256 * in[p + 1]; p += 2;
  NLEN = in[p] + 256 * in[p + 1]; p += 2;
  
  /*check if 16-bit NLEN is really the one's complement of LEN*/
  if(LEN + NLEN != 65535) return 21; /*error: NLEN is not one's complement of LEN*/
  
  if((*pos) + LEN >= out->size) { if(!ucvector_resize(out, (*pos) + LEN)) return 9915; }
  
  /*read the literal data: LEN bytes are now stored in the out buffer*/
  if(p + LEN > inlength) return 23; /*error: reading outside of in buffer*/
  for(n = 0; n < LEN; n++) out->data[(*pos)++] = in[p++];
  
  (*bp) = p * 8;
  
  return error;
}

/*inflate the deflated data (cfr. deflate spec); return value is the error*/
unsigned LodeFlate_inflate(ucvector* out, const unsigned char* in, size_t insize, size_t inpos)
{
  size_t bp = 0; /*bit pointer in the "in" data, current byte is bp >> 3, current bit is bp & 0x7 (from lsb to msb of the byte)*/
  unsigned BFINAL = 0;
  size_t pos = 0; /*byte position in the out buffer*/
  
  unsigned error = 0;
  
  while(!BFINAL)
  {
    unsigned BTYPE;
    if((bp >> 3) >= insize) return 52; /*error, bit pointer will jump past memory*/
    BFINAL = readBitFromStream(&bp, &in[inpos]);
    BTYPE = 1 * readBitFromStream(&bp, &in[inpos]); BTYPE += 2 * readBitFromStream(&bp, &in[inpos]);

    if(BTYPE == 3) return 20; /*error: invalid BTYPE*/
    else if(BTYPE == 0) error = inflateNoCompression(out, &in[inpos], &bp, &pos, insize); /*no compression*/
    else error = inflateHuffmanBlock(out, &in[inpos], &bp, &pos, insize, BTYPE); /*compression, BTYPE 01 or 10*/
    if(error) return error;
  }
  
  if(!ucvector_resize(out, pos)) error = 9916; /*Only now we know the true size of out, resize it to that*/
  
  return error;
}

#endif /*LODEPNG_COMPILE_DECODER*/

#ifdef LODEPNG_COMPILE_ENCODER

/* ////////////////////////////////////////////////////////////////////////// */
/* / Deflator                                                               / */
/* ////////////////////////////////////////////////////////////////////////// */

static const size_t MAX_SUPPORTED_DEFLATE_LENGTH = 258;

/*bitlen is the size in bits of the code*/
static void addHuffmanSymbol(size_t* bp, ucvector* compressed, unsigned code, unsigned bitlen)
{
  addBitsToStreamReversed(bp, compressed, code, bitlen);
}

/*search the index in the array, that has the largest value smaller than or equal to the given value, given array must be sorted (if no value is smaller, it returns the size of the given array)*/
static size_t searchCodeIndex(const unsigned* array, size_t array_size, size_t value)
{
  /*linear search implementation*/
  /*for(size_t i = 1; i < array_size; i++) if(array[i] > value) return i - 1;
  return array_size - 1;*/
  
  /*binary search implementation (not that much faster) (precondition: array_size > 0)*/
  size_t left  = 1;
  size_t right = array_size - 1;
  while(left <= right)
  {
    size_t mid = (left + right) / 2;
    if(array[mid] <= value) left = mid + 1; /*the value to find is more to the right*/
    else if(array[mid - 1] > value) right = mid - 1; /*the value to find is more to the left*/
    else return mid - 1;
  }
  return array_size - 1;
}

static void addLengthDistance(uivector* values, size_t length, size_t distance)
{
  /*values in encoded vector are those used by deflate:
  0-255: literal bytes
  256: end
  257-285: length/distance pair (length code, followed by extra length bits, distance code, extra distance bits)
  286-287: invalid*/

  unsigned length_code = (unsigned)searchCodeIndex(LENGTHBASE, 29, length);
  unsigned extra_length = (unsigned)(length - LENGTHBASE[length_code]);
  unsigned dist_code = (unsigned)searchCodeIndex(DISTANCEBASE, 30, distance);
  unsigned extra_distance = (unsigned)(distance - DISTANCEBASE[dist_code]);
  
  uivector_push_back(values, length_code + FIRST_LENGTH_CODE_INDEX);
  uivector_push_back(values, extra_length);
  uivector_push_back(values, dist_code);
  uivector_push_back(values, extra_distance);
}

#if USE_BRUTE_FORCE_ENCODING
#define encodeLZ77 encodeLZ77_brute
/*the "brute force" version of the encodeLZ7 algorithm, not used anymore, kept here for reference*/
static unsigned encodeLZ77_brute(uivector* out, const unsigned char* in, size_t size, unsigned windowSize)
{
  size_t pos;
  /*using pointer instead of vector for input makes it faster when NOT using optimization when compiling; no influence if optimization is used*/
  for(pos = 0; pos < size; pos++)
  {
    /*Phase 1: doxygen images often have long runs of the same color, try to find them*/   
    const int minLength = 4; // Minimum length for a run to make sense
    
    if(pos < size - minLength * 4)
    {
      size_t p, fp;
      size_t current_length;
      
      /*RGBA pixel run?*/
      p  = pos;
      fp = pos + 4;
      current_length = 0;
      
      while(fp < size && in[p] == in[fp] && current_length < MAX_SUPPORTED_DEFLATE_LENGTH)
      {
        ++p;
        ++fp;
        ++current_length;
      }
      
      if (current_length > (minLength - 1 ) * 4) /*worth using?*/
      {
        uivector_push_back(out, in[pos    ]);
        uivector_push_back(out, in[pos + 1]);
        uivector_push_back(out, in[pos + 2]);
        uivector_push_back(out, in[pos + 3]);
        addLengthDistance(out, current_length, 4);
        
        pos += current_length + 4 - 1; /*-1 for loop's pos++*/
        continue;
      }
      
      /*RGB pixel run?*/
      p  = pos;
      fp = pos + 3;
      current_length = 0;
      
      while(fp < size && in[p] == in[fp] && current_length < MAX_SUPPORTED_DEFLATE_LENGTH)
      {
        ++p;
        ++fp;
        ++current_length;
      }
      
      if (current_length > (minLength - 1 ) * 3) /*worth using?*/
      {
        uivector_push_back(out, in[pos    ]);
        uivector_push_back(out, in[pos + 1]);
        uivector_push_back(out, in[pos + 2]);
        addLengthDistance(out, current_length, 3);
        
        pos += current_length + 3 - 1; /*-1 for loop's pos++*/
        continue;
      }
    }

    size_t length = 0, offset = 0; /*the length and offset found for the current position*/
    size_t max_offset = pos < windowSize ? pos : windowSize; /*how far back to test*/
    size_t current_offset;
  
    /**search for the longest string**/
    for(current_offset = 1; current_offset < max_offset; current_offset++) /*search backwards through all possible distances (=offsets)*/
    {
      size_t backpos = pos - current_offset;
      if(in[backpos] == in[pos])
      {
        /*test the next characters*/
        size_t current_length = 1;
        size_t backtest = backpos + 1;
        size_t foretest = pos + 1;
        while(foretest < size && in[backtest] == in[foretest] && current_length < MAX_SUPPORTED_DEFLATE_LENGTH) /*maximum supporte length by deflate is max length*/
        {
          if(backpos >= pos) backpos -= current_offset; /*continue as if we work on the decoded bytes after pos by jumping back before pos*/
          current_length++;
          backtest++;
          foretest++;
        }
        if(current_length > length)
        {
          length = current_length; /*the longest length*/
          offset = current_offset; /*the offset that is related to this longest length*/
          if(current_length == MAX_SUPPORTED_DEFLATE_LENGTH) break; /*you can jump out of this for loop once a length of max length is found (gives significant speed gain)*/
        }
      }
    }
    
    /**encode it as length/distance pair or literal value**/
    if(length < 3) /*only lengths of 3 or higher are supported as length/distance pair*/
    {
      uivector_push_back(out, in[pos]);
    }
    else
    {
      addLengthDistance(out, length, offset);
      pos += (length - 1);
    }
  } /*end of the loop through each character of input*/

  return 0;
}
#endif

/*
static const unsigned HASH_NUM_VALUES = 65536;
static const unsigned HASH_NUM_CHARACTERS = 6;
static const unsigned HASH_SHIFT = 2;
Good and fast values: HASH_NUM_VALUES=65536, HASH_NUM_CHARACTERS=6, HASH_SHIFT=2
making HASH_NUM_CHARACTERS larger (like 8), makes the file size larger but is a bit faster
making HASH_NUM_CHARACTERS smaller (like 3), makes the file size smaller but is slower
*/

#if !defined(USE_BRUTE_FORCE_ENCODING)
static unsigned getHash(const unsigned char* data, size_t size, size_t pos)
{
  unsigned result = 0;
  size_t amount, i;
  if(pos >= size) return 0;
  amount = HASH_NUM_CHARACTERS; if(pos + amount >= size) amount = size - pos;
  for(i = 0; i < amount; i++) result ^= (data[pos + i] << (i * HASH_SHIFT));
  return result % HASH_NUM_VALUES;
}

/*LZ77-encode the data using a hash table technique to let it encode faster. Return value is error code*/
static unsigned encodeLZ77(uivector* out, const unsigned char* in, size_t size, unsigned windowSize)
{
  /**generate hash table**/
  vector table; /*HASH_NUM_VALUES uivectors; this represents what would be an std::vector<std::vector<unsigned> > in C++*/
  uivector tablepos1, tablepos2;
  unsigned pos, i, error = 0;
  
  vector_init(&table, sizeof(uivector));
  if(!vector_resize(&table, HASH_NUM_VALUES)) return 9917;
  for(i = 0; i < HASH_NUM_VALUES; i++)
  {
    uivector* v = (uivector*)vector_get(&table, i);
    uivector_init(v);
  }

  /*remember start and end positions in the tables to searching in*/
  uivector_init(&tablepos1);
  uivector_init(&tablepos2);
  if(!uivector_resizev(&tablepos1, HASH_NUM_VALUES, 0)) error = 9918;
  if(!uivector_resizev(&tablepos2, HASH_NUM_VALUES, 0)) error = 9919;
  
  if(!error)
  {
    for(pos = 0; pos < size; pos++)
    {
      unsigned length = 0, offset = 0; /*the length and offset found for the current position*/
      unsigned max_offset = pos < windowSize ? pos : windowSize; /*how far back to test*/
      unsigned tablepos;
    
      /*/search for the longest string*/
      /*first find out where in the table to start (the first value that is in the range from "pos - max_offset" to "pos")*/
      unsigned hash = getHash(in, size, pos);
      if(!uivector_push_back((uivector*)vector_get(&table, hash), pos))  { error = 9920; break; }
      
      while(((uivector*)vector_get(&table, hash))->data[tablepos1.data[hash]] < pos - max_offset) tablepos1.data[hash]++; /*it now points to the first value in the table for which the index is larger than or equal to pos - max_offset*/
      while(((uivector*)vector_get(&table, hash))->data[tablepos2.data[hash]] < pos) tablepos2.data[hash]++; /*it now points to the first value in the table for which the index is larger than or equal to pos*/

      for(tablepos = tablepos2.data[hash] - 1; tablepos >= tablepos1.data[hash] && tablepos < tablepos2.data[hash]; tablepos--)
      {
        unsigned backpos = ((uivector*)vector_get(&table, hash))->data[tablepos];
        unsigned current_offset = pos - backpos;

        /*test the next characters*/
        unsigned current_length = 0;
        unsigned backtest = backpos;
        unsigned foretest = pos;
        while(foretest < size && in[backtest] == in[foretest] && current_length < MAX_SUPPORTED_DEFLATE_LENGTH) /*maximum supporte length by deflate is max length*/
        {
          if(backpos >= pos) backpos -= current_offset; /*continue as if we work on the decoded bytes after pos by jumping back before pos*/
          current_length++;
          backtest++;
          foretest++;
        }
        if(current_length > length)
        {
          length = current_length; /*the longest length*/
          offset = current_offset; /*the offset that is related to this longest length*/
          if(current_length == MAX_SUPPORTED_DEFLATE_LENGTH) break; /*you can jump out of this for loop once a length of max length is found (gives significant speed gain)*/
        }
      }
      
      /**encode it as length/distance pair or literal value**/
      if(length < 3) /*only lengths of 3 or higher are supported as length/distance pair*/
      {
        if(!uivector_push_back(out, in[pos])) { error = 9921; break; }
      }
      else
      {
        unsigned j;
        addLengthDistance(out, length, offset);
        for(j = 0; j < length - 1; j++)
        {
          pos++;
          if(!uivector_push_back((uivector*)vector_get(&table, getHash(in, size, pos)), pos)) { error = 9922; break; }
        }
      }
    } /*end of the loop through each character of input*/
  } /*end of "if(!error)"*/
  
  /*cleanup*/
  for(i = 0; i < table.size; i++)
  {
    uivector* v = (uivector*)vector_get(&table, i);
    uivector_cleanup(v);
  }
  vector_cleanup(&table);
  uivector_cleanup(&tablepos1);
  uivector_cleanup(&tablepos2);
  return error;
}
#endif

/* /////////////////////////////////////////////////////////////////////////// */

static unsigned deflateNoCompression(ucvector* out, const unsigned char* data, size_t datasize)
{
  /*non compressed deflate block data: 1 bit BFINAL,2 bits BTYPE,(5 bits): it jumps to start of next byte, 2 bytes LEN, 2 bytes NLEN, LEN bytes literal DATA*/
  
  size_t i, j, numdeflateblocks = datasize / 65536 + 1;
  unsigned datapos = 0;
  for(i = 0; i < numdeflateblocks; i++)
  {
    unsigned BFINAL, BTYPE, LEN, NLEN;
    unsigned char firstbyte;
    
    BFINAL = (i == numdeflateblocks - 1);
    BTYPE = 0;
    
    firstbyte = (unsigned char)(BFINAL + ((BTYPE & 1) << 1) + ((BTYPE & 2) << 1));
    ucvector_push_back(out, firstbyte);
    
    LEN = 65535;
    if(datasize - datapos < 65535) LEN = (unsigned)datasize - datapos;
    NLEN = 65535 - LEN;
    
    ucvector_push_back(out, (unsigned char)(LEN % 256));
    ucvector_push_back(out, (unsigned char)(LEN / 256));
    ucvector_push_back(out, (unsigned char)(NLEN % 256));
    ucvector_push_back(out, (unsigned char)(NLEN / 256));

    /*Decompressed data*/
    for(j = 0; j < 65535 && datapos < datasize; j++)
    {
      ucvector_push_back(out, data[datapos++]);
    }
  }
  
  return 0;
}

/*write the encoded data, using lit/len as well as distance codes*/
static void writeLZ77data(size_t* bp, ucvector* out, const uivector* lz77_encoded, const HuffmanTree* codes, const HuffmanTree* codesD)
{
  size_t i = 0;
  for(i = 0; i < lz77_encoded->size; i++)
  {
    unsigned val = lz77_encoded->data[i];
    addHuffmanSymbol(bp, out, HuffmanTree_getCode(codes, val), HuffmanTree_getLength(codes, val));
    if(val > 256) /*for a length code, 3 more things have to be added*/
    {
      unsigned length_index = val - FIRST_LENGTH_CODE_INDEX;
      unsigned n_length_extra_bits = LENGTHEXTRA[length_index];
      unsigned length_extra_bits = lz77_encoded->data[++i];
      
      unsigned distance_code = lz77_encoded->data[++i];
      
      unsigned distance_index = distance_code;
      unsigned n_distance_extra_bits = DISTANCEEXTRA[distance_index];
      unsigned distance_extra_bits = lz77_encoded->data[++i];
      
      addBitsToStream(bp, out, length_extra_bits, n_length_extra_bits);
      addHuffmanSymbol(bp, out, HuffmanTree_getCode(codesD, distance_code), HuffmanTree_getLength(codesD, distance_code));
      addBitsToStream(bp, out, distance_extra_bits, n_distance_extra_bits);
    }
  }
}

static unsigned deflateDynamic(ucvector* out, const unsigned char* data, size_t datasize, const LodeZlib_DeflateSettings* settings)
{
  /*
  after the BFINAL and BTYPE, the dynamic block consists out of the following:
  - 5 bits HLIT, 5 bits HDIST, 4 bits HCLEN
  - (HCLEN+4)*3 bits code lengths of code length alphabet
  - HLIT + 257 code lenghts of lit/length alphabet (encoded using the code length alphabet, + possible repetition codes 16, 17, 18)
  - HDIST + 1 code lengths of distance alphabet (encoded using the code length alphabet, + possible repetition codes 16, 17, 18)
  - compressed data
  - 256 (end code)
  */
  
  unsigned error = 0;
  
  uivector lz77_encoded;
  HuffmanTree codes; /*tree for literal values and length codes*/
  HuffmanTree codesD; /*tree for distance codes*/
  HuffmanTree codelengthcodes;
  uivector frequencies;
  uivector frequenciesD;
  uivector amounts; /*the amounts in the "normal" order*/
  uivector lldl;
  uivector lldll; /*lit/len & dist code lenghts*/
  uivector clcls;
  
  unsigned BFINAL = 1; /*make only one block... the first and final one*/
  size_t numcodes, numcodesD, i, bp = 0; /*the bit pointer*/
  unsigned HLIT, HDIST, HCLEN;
  
  uivector_init(&lz77_encoded);
  HuffmanTree_init(&codes);
  HuffmanTree_init(&codesD);
  HuffmanTree_init(&codelengthcodes);
  uivector_init(&frequencies);
  uivector_init(&frequenciesD);
  uivector_init(&amounts);
  uivector_init(&lldl);
  uivector_init(&lldll);
  uivector_init(&clcls);
  
  while(!error) /*the goto-avoiding while construct: break out to go to the cleanup phase, a break at the end makes sure the while is never repeated*/
  {
    if(settings->useLZ77)
    {
      error = encodeLZ77(&lz77_encoded, data, datasize, settings->windowSize); /*LZ77 encoded*/
      if(error) break;
    }
    else
    {
      if(!uivector_resize(&lz77_encoded, datasize)) { error = 9923; break; }
      for(i = 0; i < datasize; i++) lz77_encoded.data[i] = data[i]; /*no LZ77, but still will be Huffman compressed*/
    }
    
    if(!uivector_resizev(&frequencies, 286, 0)) { error = 9924; break; }
    if(!uivector_resizev(&frequenciesD, 30, 0)) { error = 9925; break; }
    for(i = 0; i < lz77_encoded.size; i++)
    {
      unsigned symbol = lz77_encoded.data[i];
      frequencies.data[symbol]++;
      if(symbol > 256)
      {
        unsigned dist = lz77_encoded.data[i + 2];
        frequenciesD.data[dist]++;
        i += 3;
      }
    }
    frequencies.data[256] = 1; /*there will be exactly 1 end code, at the end of the block*/
    
    error = HuffmanTree_makeFromFrequencies(&codes, frequencies.data, frequencies.size, 15);
    if(error) break;
    error = HuffmanTree_makeFromFrequencies(&codesD, frequenciesD.data, frequenciesD.size, 15);
    if(error) break;
    
    addBitToStream(&bp, out, BFINAL);
    addBitToStream(&bp, out, 0); /*first bit of BTYPE "dynamic"*/
    addBitToStream(&bp, out, 1); /*second bit of BTYPE "dynamic"*/
  
    numcodes = codes.numcodes; if(numcodes > 286) numcodes = 286;
    numcodesD = codesD.numcodes; if(numcodesD > 30) numcodesD = 30;
    for(i = 0; i < numcodes; i++) uivector_push_back(&lldll, HuffmanTree_getLength(&codes, (unsigned)i));
    for(i = 0; i < numcodesD; i++) uivector_push_back(&lldll, HuffmanTree_getLength(&codesD, (unsigned)i));
    
    /*make lldl smaller by using repeat codes 16 (copy length 3-6 times), 17 (3-10 zeroes), 18 (11-138 zeroes)*/
    for(i = 0; i < (unsigned)lldll.size; i++)
    {
      unsigned j = 0;
      while(i + j + 1 < (unsigned)lldll.size && lldll.data[i + j + 1] == lldll.data[i]) j++;
      
      if(lldll.data[i] == 0 && j >= 2)
      {
        j++; /*include the first zero*/
        if(j <= 10) { uivector_push_back(&lldl, 17); uivector_push_back(&lldl, j - 3); }
        else
        {
          if(j > 138) j = 138;
          uivector_push_back(&lldl, 18); uivector_push_back(&lldl, j - 11);
        }
        i += (j - 1);
      }
      else if(j >= 3)
      {
        size_t k;
        unsigned num = j / 6, rest = j % 6;
        uivector_push_back(&lldl, lldll.data[i]);
        for(k = 0; k < num; k++) { uivector_push_back(&lldl, 16); uivector_push_back(&lldl,    6 - 3); }
        if(rest >= 3)            { uivector_push_back(&lldl, 16); uivector_push_back(&lldl, rest - 3); }
        else j -= rest;
        i += j;
      }
      else uivector_push_back(&lldl, lldll.data[i]);
    }
    
    /*generate huffmantree for the length codes of lit/len and dist codes*/
    if(!uivector_resizev(&amounts, 19, 0)) { error = 9926; break; } /*16 possible lengths (0-15) and 3 repeat codes (16, 17 and 18)*/
    for(i = 0; i < lldl.size; i++)
    {
      amounts.data[lldl.data[i]]++;
      if(lldl.data[i] >= 16) i++; /*after a repeat code come the bits that specify the amount, those don't need to be in the amounts calculation*/
    }
    
    error = HuffmanTree_makeFromFrequencies(&codelengthcodes, amounts.data, amounts.size, 7);
    if(error) break;
    
    if(!uivector_resize(&clcls, 19)) { error = 9927; break; }
    for(i = 0; i < 19; i++) clcls.data[i] = HuffmanTree_getLength(&codelengthcodes, CLCL[i]); /*lenghts of code length tree is in the order as specified by deflate*/
    while(clcls.data[clcls.size - 1] == 0 && clcls.size > 4)
    {
      if(!uivector_resize(&clcls, clcls.size - 1)) { error = 9928; break; } /*remove zeros at the end, but minimum size must be 4*/
    }
    if(error) break;
    
    /*write the HLIT, HDIST and HCLEN values*/
    HLIT = (unsigned)(numcodes - 257);
    HDIST = (unsigned)(numcodesD - 1);
    HCLEN = (unsigned)clcls.size - 4;
    addBitsToStream(&bp, out, HLIT, 5);
    addBitsToStream(&bp, out, HDIST, 5);
    addBitsToStream(&bp, out, HCLEN, 4);
    
    /*write the code lenghts of the code length alphabet*/
    for(i = 0; i < HCLEN + 4; i++) addBitsToStream(&bp, out, clcls.data[i], 3);
  
    /*write the lenghts of the lit/len AND the dist alphabet*/
    for(i = 0; i < lldl.size; i++)
    {
      addHuffmanSymbol(&bp, out, HuffmanTree_getCode(&codelengthcodes, lldl.data[i]), HuffmanTree_getLength(&codelengthcodes, lldl.data[i]));
      /*extra bits of repeat codes*/
      if(lldl.data[i] == 16) addBitsToStream(&bp, out, lldl.data[++i], 2);
      else if(lldl.data[i] == 17) addBitsToStream(&bp, out, lldl.data[++i], 3);
      else if(lldl.data[i] == 18) addBitsToStream(&bp, out, lldl.data[++i], 7);
    }
    
    /*write the compressed data symbols*/
    writeLZ77data(&bp, out, &lz77_encoded, &codes, &codesD);
    if(HuffmanTree_getLength(&codes, 256) == 0) { error = 64; break; } /*the length of the end code 256 must be larger than 0*/
    addHuffmanSymbol(&bp, out, HuffmanTree_getCode(&codes, 256), HuffmanTree_getLength(&codes, 256)); /*end code*/
    
    break; /*end of error-while*/
  }
  
  /*cleanup*/
  uivector_cleanup(&lz77_encoded);
  HuffmanTree_cleanup(&codes);
  HuffmanTree_cleanup(&codesD);
  HuffmanTree_cleanup(&codelengthcodes);
  uivector_cleanup(&frequencies);
  uivector_cleanup(&frequenciesD);
  uivector_cleanup(&amounts);
  uivector_cleanup(&lldl);
  uivector_cleanup(&lldll);
  uivector_cleanup(&clcls);
  
  return error;
}

static unsigned deflateFixed(ucvector* out, const unsigned char* data, size_t datasize, const LodeZlib_DeflateSettings* settings)
{
  HuffmanTree codes; /*tree for literal values and length codes*/
  HuffmanTree codesD; /*tree for distance codes*/
  
  unsigned BFINAL = 1; /*make only one block... the first and final one*/
  unsigned error = 0;
  size_t i, bp = 0; /*the bit pointer*/
  
  HuffmanTree_init(&codes);
  HuffmanTree_init(&codesD);
  
  generateFixedTree(&codes);
  generateDistanceTree(&codesD);
  
  addBitToStream(&bp, out, BFINAL);
  addBitToStream(&bp, out, 1); /*first bit of BTYPE*/
  addBitToStream(&bp, out, 0); /*second bit of BTYPE*/
  
  if(settings->useLZ77) /*LZ77 encoded*/
  {
    uivector lz77_encoded;
    uivector_init(&lz77_encoded);
    error = encodeLZ77(&lz77_encoded, data, datasize, settings->windowSize);
    if(!error) writeLZ77data(&bp, out, &lz77_encoded, &codes, &codesD);
    uivector_cleanup(&lz77_encoded);
  }
  else /*no LZ77, but still will be Huffman compressed*/
  {
    for(i = 0; i < datasize; i++) addHuffmanSymbol(&bp, out, HuffmanTree_getCode(&codes, data[i]), HuffmanTree_getLength(&codes, data[i]));
  }
  if(!error) addHuffmanSymbol(&bp, out, HuffmanTree_getCode(&codes, 256), HuffmanTree_getLength(&codes, 256)); /*"end" code*/
  
  /*cleanup*/
  HuffmanTree_cleanup(&codes);
  HuffmanTree_cleanup(&codesD);
  
  return error;
}

unsigned LodeFlate_deflate(ucvector* out, const unsigned char* data, size_t datasize, const LodeZlib_DeflateSettings* settings)
{
  unsigned error = 0;
  if(settings->btype == 0) error = deflateNoCompression(out, data, datasize);
  else if(settings->btype == 1) error = deflateFixed(out, data, datasize, settings);
  else if(settings->btype == 2) error = deflateDynamic(out, data, datasize, settings);
  else error = 61;
  return error;
}

#endif /*LODEPNG_COMPILE_DECODER*/

/* ////////////////////////////////////////////////////////////////////////// */
/* / Adler32                                                                  */
/* ////////////////////////////////////////////////////////////////////////// */

static unsigned update_adler32(unsigned adler, const unsigned char* data, unsigned len)
{
   unsigned s1 = adler & 0xffff;
   unsigned s2 = (adler >> 16) & 0xffff;
   
  while(len > 0)
  {
    /*at least 5550 sums can be done before the sums overflow, saving us from a lot of module divisions*/
    unsigned amount = len > 5550 ? 5550 : len;
    len -= amount;
    while(amount > 0)
    {
      s1 = (s1 + *data++);
      s2 = (s2 + s1);
      amount--;
    }
    s1 %= 65521;
    s2 %= 65521;
  }
  
  return (s2 << 16) | s1;
}

/*Return the adler32 of the bytes data[0..len-1]*/
static unsigned adler32(const unsigned char* data, unsigned len)
{
  return update_adler32(1L, data, len);
}

/* ////////////////////////////////////////////////////////////////////////// */
/* / Reading and writing single bits and bytes from/to stream for Zlib      / */
/* ////////////////////////////////////////////////////////////////////////// */

#ifdef LODEPNG_COMPILE_ENCODER
void LodeZlib_add32bitInt(ucvector* buffer, unsigned value)
{
  ucvector_push_back(buffer, (unsigned char)((value >> 24) & 0xff));
  ucvector_push_back(buffer, (unsigned char)((value >> 16) & 0xff));
  ucvector_push_back(buffer, (unsigned char)((value >>  8) & 0xff));
  ucvector_push_back(buffer, (unsigned char)((value      ) & 0xff));
}
#endif /*LODEPNG_COMPILE_ENCODER*/

unsigned LodeZlib_read32bitInt(const unsigned char* buffer)
{
  return (buffer[0] << 24) | (buffer[1] << 16) | (buffer[2] << 8) | buffer[3];
}

/* ////////////////////////////////////////////////////////////////////////// */
/* / Zlib                                                                   / */
/* ////////////////////////////////////////////////////////////////////////// */

#ifdef LODEPNG_COMPILE_DECODER

unsigned LodeZlib_decompress(unsigned char** out, size_t* outsize, const unsigned char* in, size_t insize, const LodeZlib_DecompressSettings* settings)
{
  unsigned error = 0;
  unsigned CM, CINFO, FDICT;
  ucvector outv;
  
  if(insize < 2) { error = 53; return error; } /*error, size of zlib data too small*/
  /*read information from zlib header*/
  if((in[0] * 256 + in[1]) % 31 != 0) { error = 24; return error; } /*error: 256 * in[0] + in[1] must be a multiple of 31, the FCHECK value is supposed to be made that way*/

  CM = in[0] & 15;
  CINFO = (in[0] >> 4) & 15;
  /*FCHECK = in[1] & 31; //FCHECK is already tested above*/
  FDICT = (in[1] >> 5) & 1;
  /*FLEVEL = (in[1] >> 6) & 3; //not really important, all it does it to give a compiler warning about unused variable, we don't care what encoding setting the encoder used*/
  
  if(CM != 8 || CINFO > 7) { error = 25; return error; } /*error: only compression method 8: inflate with sliding window of 32k is supported by the PNG spec*/
  if(FDICT != 0) { error = 26; return error; } /*error: the specification of PNG says about the zlib stream: "The additional flags shall not specify a preset dictionary."*/
  
  ucvector_init_buffer(&outv, *out, *outsize); /*ucvector-controlled version of the output buffer, for dynamic array*/
  error = LodeFlate_inflate(&outv, in, insize, 2);
  *out = outv.data;
  *outsize = outv.size;
  if(error) return error;
  
  if(!settings->ignoreAdler32)
  {
    unsigned ADLER32 = LodeZlib_read32bitInt(&in[insize - 4]);
    unsigned checksum = adler32(outv.data, (unsigned)outv.size);
    if(checksum != ADLER32) { error = 58; return error; }
  }
  
  return error;
}

#endif /*LODEPNG_COMPILE_DECODER*/

#ifdef LODEPNG_COMPILE_ENCODER

unsigned LodeZlib_compress(unsigned char** out, size_t* outsize, const unsigned char* in, size_t insize, const LodeZlib_DeflateSettings* settings)
{
  /*initially, *out must be NULL and outsize 0, if you just give some random *out that's pointing to a non allocated buffer, this'll crash*/
  ucvector deflatedata, outv;
  size_t i;
  unsigned error;
  
  unsigned ADLER32;
  /*zlib data: 1 byte CMF (CM+CINFO), 1 byte FLG, deflate data, 4 byte ADLER32 checksum of the Decompressed data*/
  unsigned CMF = 120; /*0b01111000: CM 8, CINFO 7. With CINFO 7, any window size up to 32768 can be used.*/
  unsigned FLEVEL = 0;
  unsigned FDICT = 0;
  unsigned CMFFLG = 256 * CMF + FDICT * 32 + FLEVEL * 64;
  unsigned FCHECK = 31 - CMFFLG % 31;
  CMFFLG += FCHECK;
  
  ucvector_init_buffer(&outv, *out, *outsize); /*ucvector-controlled version of the output buffer, for dynamic array*/
  
  ucvector_push_back(&outv, (unsigned char)(CMFFLG / 256));
  ucvector_push_back(&outv, (unsigned char)(CMFFLG % 256));
  
  ucvector_init(&deflatedata);
  error = LodeFlate_deflate(&deflatedata, in, insize, settings);
  
  if(!error)
  {
    ADLER32 = adler32(in, (unsigned)insize);
    for(i = 0; i < deflatedata.size; i++) ucvector_push_back(&outv, deflatedata.data[i]);
    ucvector_cleanup(&deflatedata);
    LodeZlib_add32bitInt(&outv, ADLER32);
  }
  
  *out = outv.data;
  *outsize = outv.size;
  
  return error;
}

#endif /*LODEPNG_COMPILE_ENCODER*/

#endif /*LODEPNG_COMPILE_ZLIB*/

/* ////////////////////////////////////////////////////////////////////////// */

#ifdef LODEPNG_COMPILE_ENCODER

void LodeZlib_DeflateSettings_init(LodeZlib_DeflateSettings* settings)
{
  settings->btype = 2; /*compress with dynamic huffman tree (not in the mathematical sense, just not the predefined one)*/
  settings->useLZ77 = 1;
  settings->windowSize = 2048; /*this is a good tradeoff between speed and compression ratio*/
}

const LodeZlib_DeflateSettings LodeZlib_defaultDeflateSettings = {2, 1, 2048};

#endif /*LODEPNG_COMPILE_ENCODER*/

#ifdef LODEPNG_COMPILE_DECODER

void LodeZlib_DecompressSettings_init(LodeZlib_DecompressSettings* settings)
{
  settings->ignoreAdler32 = 0;
}

const LodeZlib_DecompressSettings LodeZlib_defaultDecompressSettings = {0};

#endif /*LODEPNG_COMPILE_DECODER*/

/* ////////////////////////////////////////////////////////////////////////// */
/* ////////////////////////////////////////////////////////////////////////// */
/* ////////////////////////////////////////////////////////////////////////// */
/* ////////////////////////////////////////////////////////////////////////// */
/* ////////////////////////////////////////////////////////////////////////// */
/* // End of Zlib related code, now comes the PNG related code that uses it// */
/* ////////////////////////////////////////////////////////////////////////// */
/* ////////////////////////////////////////////////////////////////////////// */
/* ////////////////////////////////////////////////////////////////////////// */
/* ////////////////////////////////////////////////////////////////////////// */
/* ////////////////////////////////////////////////////////////////////////// */

#ifdef LODEPNG_COMPILE_PNG

/*
The two functions below (LodePNG_decompress and LodePNG_compress) directly call the
LodeZlib_decompress and LodeZlib_compress functions. The only purpose of the functions
below, is to provide the ability to let LodePNG use a different Zlib encoder by only
changing the two functions below, instead of changing it inside the vareous places
in the other LodePNG functions.

*out must be NULL and *outsize must be 0 initially, and after the function is done,
*out must point to the decompressed data, *outsize must be the size of it, and must
be the size of the useful data in bytes, not the alloc size.
*/

#ifdef LODEPNG_COMPILE_DECODER
static unsigned LodePNG_decompress(unsigned char** out, size_t* outsize, const unsigned char* in, size_t insize, const LodeZlib_DecompressSettings* settings)
{
  return LodeZlib_decompress(out, outsize, in, insize, settings);
}
#endif /*LODEPNG_COMPILE_DECODER*/
#ifdef LODEPNG_COMPILE_ENCODER
static unsigned LodePNG_compress(unsigned char** out, size_t* outsize, const unsigned char* in, size_t insize, const LodeZlib_DeflateSettings* settings)
{
  return LodeZlib_compress(out, outsize, in, insize, settings);
}
#endif /*LODEPNG_COMPILE_ENCODER*/

/* ////////////////////////////////////////////////////////////////////////// */
/* / CRC32                                                                  / */
/* ////////////////////////////////////////////////////////////////////////// */

static unsigned Crc32_crc_table_computed = 0;
static unsigned Crc32_crc_table[256];

/*Make the table for a fast CRC.*/
static void Crc32_make_crc_table(void)
{
  unsigned int c, k, n;
  for(n = 0; n < 256; n++)
  {
    c = n;
    for(k = 0; k < 8; k++)
    {
      if(c & 1) c = (unsigned int)(0xedb88320L ^ (c >> 1));
      else c = c >> 1;
    }
    Crc32_crc_table[n] = c;
  }
  Crc32_crc_table_computed = 1;
}

/*Update a running CRC with the bytes buf[0..len-1]--the CRC should be 
initialized to all 1's, and the transmitted value is the 1's complement of the
final running CRC (see the crc() routine below).*/
static unsigned Crc32_update_crc(const unsigned char* buf, unsigned int crc, size_t len)
{
  unsigned int c = crc;
  size_t n;

  if(!Crc32_crc_table_computed) Crc32_make_crc_table();
  for(n = 0; n < len; n++)
  {
    c = Crc32_crc_table[(c ^ buf[n]) & 0xff] ^ (c >> 8);
  }
  return c;
}

/*Return the CRC of the bytes buf[0..len-1].*/
static unsigned Crc32_crc(const unsigned char* buf, size_t len)
{
  return Crc32_update_crc(buf, 0xffffffffu, len) ^ 0xffffffffu;
}

/* ////////////////////////////////////////////////////////////////////////// */
/* / Reading and writing single bits and bytes from/to stream for LodePNG   / */
/* ////////////////////////////////////////////////////////////////////////// */

static unsigned char readBitFromReversedStream(size_t* bitpointer, const unsigned char* bitstream)
{
  unsigned char result = (unsigned char)((bitstream[(*bitpointer) >> 3] >> (7 - ((*bitpointer) & 0x7))) & 1);
  (*bitpointer)++;
  return result;
}

static unsigned readBitsFromReversedStream(size_t* bitpointer, const unsigned char* bitstream, size_t nbits)
{
  unsigned result = 0;
  size_t i;
  for(i = nbits - 1; i < nbits; i--) result += (unsigned)readBitFromReversedStream(bitpointer, bitstream) << i;
  return result;
}

#ifdef LODEPNG_COMPILE_DECODER
static void setBitOfReversedStream0(size_t* bitpointer, unsigned char* bitstream, unsigned char bit)
{
  /*the current bit in bitstream must be 0 for this to work*/
  if(bit) bitstream[(*bitpointer) >> 3] |=  (bit << (7 - ((*bitpointer) & 0x7))); /*earlier bit of huffman code is in a lesser significant bit of an earlier byte*/
  (*bitpointer)++;
}
#endif /*LODEPNG_COMPILE_DECODER*/

static void setBitOfReversedStream(size_t* bitpointer, unsigned char* bitstream, unsigned char bit)
{
  /*the current bit in bitstream may be 0 or 1 for this to work*/
  if(bit == 0) bitstream[(*bitpointer) >> 3] &=  (unsigned char)(~(1 << (7 - ((*bitpointer) & 0x7))));
  else bitstream[(*bitpointer) >> 3] |=  (1 << (7 - ((*bitpointer) & 0x7)));
  (*bitpointer)++;
}

static unsigned LodePNG_read32bitInt(const unsigned char* buffer)
{
  return (buffer[0] << 24) | (buffer[1] << 16) | (buffer[2] << 8) | buffer[3];
}

static void LodePNG_set32bitInt(unsigned char* buffer, unsigned value) /*buffer must have at least 4 allocated bytes available*/
{
  buffer[0] = (unsigned char)((value >> 24) & 0xff);
  buffer[1] = (unsigned char)((value >> 16) & 0xff);
  buffer[2] = (unsigned char)((value >>  8) & 0xff);
  buffer[3] = (unsigned char)((value      ) & 0xff);
}

#ifdef LODEPNG_COMPILE_ENCODER
static void LodePNG_add32bitInt(ucvector* buffer, unsigned value)
{
  ucvector_resize(buffer, buffer->size + 4);
  LodePNG_set32bitInt(&buffer->data[buffer->size - 4], value);
}
#endif /*LODEPNG_COMPILE_ENCODER*/

/* ////////////////////////////////////////////////////////////////////////// */
/* / PNG chunks                                                             / */
/* ////////////////////////////////////////////////////////////////////////// */

unsigned LodePNG_chunk_length(const unsigned char* chunk) /*get the length of the data of the chunk. Total chunk length has 12 bytes more.*/
{
  return LodePNG_read32bitInt(&chunk[0]);
}

void LodePNG_chunk_type(char type[5], const unsigned char* chunk) /*puts the 4-byte type in null terminated string*/
{
  unsigned i;
  for(i = 0; i < 4; i++) type[i] = chunk[4 + i];
  type[4] = 0; /*null termination char*/
}

unsigned char LodePNG_chunk_type_equals(const unsigned char* chunk, const char* type) /*check if the type is the given type*/
{
  if(strlen(type) != 4) return 0;
  return (chunk[4] == type[0] && chunk[5] == type[1] && chunk[6] == type[2] && chunk[7] == type[3]);
}

/*properties of PNG chunks gotten from capitalization of chunk type name, as defined by the standard*/
unsigned char LodePNG_chunk_critical(const unsigned char* chunk) /*0: ancillary chunk, 1: it's one of the critical chunk types*/
{
  return((chunk[4] & 32) == 0);
}

unsigned char LodePNG_chunk_private(const unsigned char* chunk) /*0: public, 1: private*/
{
  return((chunk[6] & 32) != 0);
}

unsigned char LodePNG_chunk_safetocopy(const unsigned char* chunk) /*0: the chunk is unsafe to copy, 1: the chunk is safe to copy*/
{
  return((chunk[7] & 32) != 0);
}

unsigned char* LodePNG_chunk_data(unsigned char* chunk) /*get pointer to the data of the chunk*/
{
  return &chunk[8];
}

const unsigned char* LodePNG_chunk_data_const(const unsigned char* chunk) /*get pointer to the data of the chunk*/
{
  return &chunk[8];
}

unsigned LodePNG_chunk_check_crc(const unsigned char* chunk) /*returns 0 if the crc is correct, error code if it's incorrect*/
{
  unsigned length = LodePNG_chunk_length(chunk);
  unsigned CRC = LodePNG_read32bitInt(&chunk[length + 8]);
  unsigned checksum = Crc32_crc(&chunk[4], length + 4); /*the CRC is taken of the data and the 4 chunk type letters, not the length*/
  if(CRC != checksum) return 1;
  else return 0;
}

void LodePNG_chunk_generate_crc(unsigned char* chunk) /*generates the correct CRC from the data and puts it in the last 4 bytes of the chunk*/
{
  unsigned length = LodePNG_chunk_length(chunk);
  unsigned CRC = Crc32_crc(&chunk[4], length + 4);
  LodePNG_set32bitInt(chunk + 8 + length, CRC);
}

unsigned char* LodePNG_chunk_next(unsigned char* chunk) /*don't use on IEND chunk, as there is no next chunk then*/
{
  unsigned total_chunk_length = LodePNG_chunk_length(chunk) + 12;
  return &chunk[total_chunk_length];
}

const unsigned char* LodePNG_chunk_next_const(const unsigned char* chunk) /*don't use on IEND chunk, as there is no next chunk then*/
{
  unsigned total_chunk_length = LodePNG_chunk_length(chunk) + 12;
  return &chunk[total_chunk_length];
}

unsigned LodePNG_append_chunk(unsigned char** out, size_t* outlength, const unsigned char* chunk) /*appends chunk that was already created, to the data. Returns error code.*/
{
  unsigned i;
  unsigned total_chunk_length = LodePNG_chunk_length(chunk) + 12;
  unsigned char *chunk_start, *new_buffer;
  size_t new_length = (*outlength) + total_chunk_length;
  if(new_length < total_chunk_length || new_length < (*outlength)) return 77; /*integer overflow happened*/
  
  new_buffer = (unsigned char*)realloc(*out, new_length);
  if(!new_buffer) return 9929;
  (*out) = new_buffer;
  (*outlength) = new_length;
  chunk_start = &(*out)[new_length - total_chunk_length];
  
  for(i = 0; i < total_chunk_length; i++) chunk_start[i] = chunk[i];
  
  return 0;
}

unsigned LodePNG_create_chunk(unsigned char** out, size_t* outlength, unsigned length, const char* type, const unsigned char* data) /*appends new chunk to out. Returns error code; may change memory address of out buffer*/
{
  unsigned i;
  unsigned char *chunk, *new_buffer;
  size_t new_length = (*outlength) + length + 12;
  if(new_length < length + 12 || new_length < (*outlength)) return 77; /*integer overflow happened*/
  new_buffer = (unsigned char*)realloc(*out, new_length);
  if(!new_buffer) return 9930;
  (*out) = new_buffer;
  (*outlength) = new_length;
  chunk = &(*out)[(*outlength) - length - 12];
  
  /*1: length*/
  LodePNG_set32bitInt(chunk, (unsigned)length);
  
  /*2: chunk name (4 letters)*/
  chunk[4] = type[0];
  chunk[5] = type[1];
  chunk[6] = type[2];
  chunk[7] = type[3];
  
  /*3: the data*/
  for(i = 0; i < length; i++) chunk[8 + i] = data[i];
  
  /*4: CRC (of the chunkname characters and the data)*/
  LodePNG_chunk_generate_crc(chunk);
  
  return 0;
}

/* ////////////////////////////////////////////////////////////////////////// */
/* / Color types and such                                                   / */
/* ////////////////////////////////////////////////////////////////////////// */

/*return type is a LodePNG error code*/
static unsigned checkColorValidity(unsigned colorType, unsigned bd) /*bd = bitDepth*/
{
  switch(colorType)
  {
    case 0: if(!(bd == 1 || bd == 2 || bd == 4 || bd == 8 || bd == 16)) return 37; break; /*grey*/
    case 2: if(!(                                 bd == 8 || bd == 16)) return 37; break; /*RGB*/
    case 3: if(!(bd == 1 || bd == 2 || bd == 4 || bd == 8            )) return 37; break; /*palette*/
    case 4: if(!(                                 bd == 8 || bd == 16)) return 37; break; /*grey + alpha*/
    case 6: if(!(                                 bd == 8 || bd == 16)) return 37; break; /*RGBA*/
    default: return 31;
  }
  return 0; /*allowed color type / bits combination*/
}

static unsigned getNumColorChannels(unsigned colorType)
{
  switch(colorType)
  {
    case 0: return 1; /*grey*/
    case 2: return 3; /*RGB*/
    case 3: return 1; /*palette*/
    case 4: return 2; /*grey + alpha*/
    case 6: return 4; /*RGBA*/
  }
  return 0; /*unexisting color type*/
}

static unsigned getBpp(unsigned colorType, unsigned bitDepth)
{
  return getNumColorChannels(colorType) * bitDepth; /*bits per pixel is amount of channels * bits per channel*/
}

/* ////////////////////////////////////////////////////////////////////////// */

void LodePNG_InfoColor_init(LodePNG_InfoColor* info)
{
  info->key_defined = 0;
  info->key_r = info->key_g = info->key_b = 0;
  info->colorType = 6;
  info->bitDepth = 8;
  info->palette = 0;
  info->palettesize = 0;
}

void LodePNG_InfoColor_cleanup(LodePNG_InfoColor* info)
{
  LodePNG_InfoColor_clearPalette(info);
}

void LodePNG_InfoColor_clearPalette(LodePNG_InfoColor* info)
{
  if(info->palette) free(info->palette);
  info->palettesize = 0;
}

unsigned LodePNG_InfoColor_addPalette(LodePNG_InfoColor* info, unsigned char r, unsigned char g, unsigned char b, unsigned char a)
{
  unsigned char* data;
  /*the same resize technique as C++ std::vectors is used, and here it's made so that for a palette with the max of 256 colors, it'll have the exact alloc size*/
  if(!(info->palettesize & (info->palettesize - 1))) /*if palettesize is 0 or a power of two*/
  {
    /*allocated data must be at least 4* palettesize (for 4 color bytes)*/
    size_t alloc_size = info->palettesize == 0 ? 4 : info->palettesize * 4 * 2;
    data = (unsigned char*)realloc(info->palette, alloc_size);
    if(!data) return 9931;
    else info->palette = data;
  }
  info->palette[4 * info->palettesize + 0] = r;
  info->palette[4 * info->palettesize + 1] = g;
  info->palette[4 * info->palettesize + 2] = b;
  info->palette[4 * info->palettesize + 3] = a;
  info->palettesize++;
  return 0;
}

unsigned LodePNG_InfoColor_getBpp(const LodePNG_InfoColor* info) { return getBpp(info->colorType, info->bitDepth); } /*calculate bits per pixel out of colorType and bitDepth*/
unsigned LodePNG_InfoColor_getChannels(const LodePNG_InfoColor* info) { return getNumColorChannels(info->colorType); }
unsigned LodePNG_InfoColor_isGreyscaleType(const LodePNG_InfoColor* info) { return info->colorType == 0 || info->colorType == 4; }
unsigned LodePNG_InfoColor_isAlphaType(const LodePNG_InfoColor* info) { return (info->colorType & 4) != 0; }

unsigned LodePNG_InfoColor_equal(const LodePNG_InfoColor* info1, const LodePNG_InfoColor* info2)
{
  return info1->colorType == info2->colorType
      && info1->bitDepth  == info2->bitDepth; /*palette and color key not compared*/
}

#ifdef LODEPNG_COMPILE_UNKNOWN_CHUNKS

void LodePNG_UnknownChunks_init(LodePNG_UnknownChunks* chunks)
{
  unsigned i;
  for(i = 0; i < 3; i++) chunks->data[i] = 0;
  for(i = 0; i < 3; i++) chunks->datasize[i] = 0;
}

void LodePNG_UnknownChunks_cleanup(LodePNG_UnknownChunks* chunks)
{
  unsigned i;
  for(i = 0; i < 3; i++) free(chunks->data[i]);
}

unsigned LodePNG_UnknownChunks_copy(LodePNG_UnknownChunks* dest, const LodePNG_UnknownChunks* src)
{
  unsigned i;
  
  LodePNG_UnknownChunks_cleanup(dest);
  
  for(i = 0; i < 3; i++)
  {
    size_t j;
    dest->datasize[i] = src->datasize[i];
    dest->data[i] = (unsigned char*)malloc(src->datasize[i]);
    if(!dest->data[i] && dest->datasize[i]) return 9932;
    for(j = 0; j < src->datasize[i]; j++) dest->data[i][j] = src->data[i][j];
  }
  
  return 0;
}

#endif /*LODEPNG_COMPILE_UNKNOWN_CHUNKS*/

#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS

void LodePNG_Text_init(LodePNG_Text* text)
{
  text->num = 0;
  text->keys = NULL;
  text->strings = NULL;
}

void LodePNG_Text_cleanup(LodePNG_Text* text)
{
  LodePNG_Text_clear(text);
}

unsigned LodePNG_Text_copy(LodePNG_Text* dest, const LodePNG_Text* source)
{
  size_t i = 0;
  dest->keys = 0;
  dest->strings = 0;
  dest->num = 0;
  for(i = 0; i < source->num; i++)
  {
    unsigned error = LodePNG_Text_add(dest, source->keys[i], source->strings[i]);
    if(error) return error;
  }
  return 0;
}

void LodePNG_Text_clear(LodePNG_Text* text)
{
  size_t i;
  for(i = 0; i < text->num; i++)
    {
    string_cleanup(&text->keys[i]);
    string_cleanup(&text->strings[i]);
    }
  free(text->keys);
  free(text->strings);
}

unsigned LodePNG_Text_add(LodePNG_Text* text, const char* key, const char* str)
{
  char** new_keys = (char**)(realloc(text->keys, sizeof(char*) * (text->num + 1)));
  char** new_strings = (char**)(realloc(text->strings, sizeof(char*) * (text->num + 1)));
  if(!new_keys || !new_strings)
  {
    free(new_keys);
    free(new_strings);
    return 9933;
  }
  
  text->num++;
  text->keys = new_keys;
  text->strings = new_strings;
  
  string_init(&text->keys[text->num - 1]);
  string_set(&text->keys[text->num - 1], key);
  
  string_init(&text->strings[text->num - 1]);
  string_set(&text->strings[text->num - 1], str);
  
  return 0;
}

/******************************************************************************/

void LodePNG_IText_init(LodePNG_IText* text)
{
  text->num = 0;
  text->keys = NULL;
  text->langtags = NULL;
  text->transkeys = NULL;
  text->strings = NULL;
}

void LodePNG_IText_cleanup(LodePNG_IText* text)
{
  LodePNG_IText_clear(text);
}

unsigned LodePNG_IText_copy(LodePNG_IText* dest, const LodePNG_IText* source)
{
  size_t i = 0;
  dest->keys = 0;
  dest->langtags = 0;
  dest->transkeys = 0;
  dest->strings = 0;
  dest->num = 0;
  for(i = 0; i < source->num; i++)
  {
    unsigned error = LodePNG_IText_add(dest, source->keys[i], source->langtags[i], source->transkeys[i], source->strings[i]);
    if(error) return error;
  }
  return 0;
}

void LodePNG_IText_clear(LodePNG_IText* text)
{
  size_t i;
  for(i = 0; i < text->num; i++)
    {
    string_cleanup(&text->keys[i]);
    string_cleanup(&text->langtags[i]);
    string_cleanup(&text->transkeys[i]);
    string_cleanup(&text->strings[i]);
    }
  free(text->keys);
  free(text->langtags);
  free(text->transkeys);
  free(text->strings);
}

unsigned LodePNG_IText_add(LodePNG_IText* text, const char* key, const char* langtag, const char* transkey, const char* str)
{
  char** new_keys = (char**)(realloc(text->keys, sizeof(char*) * (text->num + 1)));
  char** new_langtags = (char**)(realloc(text->langtags, sizeof(char*) * (text->num + 1)));
  char** new_transkeys = (char**)(realloc(text->transkeys, sizeof(char*) * (text->num + 1)));
  char** new_strings = (char**)(realloc(text->strings, sizeof(char*) * (text->num + 1)));
  if(!new_keys || !new_langtags || !new_transkeys || !new_strings)
  {
    free(new_keys);
    free(new_langtags);
    free(new_transkeys);
    free(new_strings);
    return 9934;
  }
  
  text->num++;
  text->keys = new_keys;
  text->langtags = new_langtags;
  text->transkeys = new_transkeys;
  text->strings = new_strings;
  
  string_init(&text->keys[text->num - 1]);
  string_set(&text->keys[text->num - 1], key);
  
  string_init(&text->langtags[text->num - 1]);
  string_set(&text->langtags[text->num - 1], langtag);
  
  string_init(&text->transkeys[text->num - 1]);
  string_set(&text->transkeys[text->num - 1], transkey);
  
  string_init(&text->strings[text->num - 1]);
  string_set(&text->strings[text->num - 1], str);
  
  return 0;
}

#endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/

void LodePNG_InfoPng_init(LodePNG_InfoPng* info)
{
  info->width = info->height = 0;
  LodePNG_InfoColor_init(&info->color);
  info->interlaceMethod = 0;
  info->compressionMethod = 0;
  info->filterMethod = 0;
#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS
  info->background_defined = 0;
  info->background_r = info->background_g = info->background_b = 0;
  
  LodePNG_Text_init(&info->text);
  LodePNG_IText_init(&info->itext);
  
  info->time_defined = 0;
  info->phys_defined = 0;
#endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/
#ifdef LODEPNG_COMPILE_UNKNOWN_CHUNKS
  LodePNG_UnknownChunks_init(&info->unknown_chunks);
#endif /*LODEPNG_COMPILE_UNKNOWN_CHUNKS*/
}

void LodePNG_InfoPng_cleanup(LodePNG_InfoPng* info)
{
  LodePNG_InfoColor_cleanup(&info->color);
#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS
  LodePNG_Text_cleanup(&info->text);
  LodePNG_IText_cleanup(&info->itext);
#endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/
#ifdef LODEPNG_COMPILE_UNKNOWN_CHUNKS
  LodePNG_UnknownChunks_cleanup(&info->unknown_chunks);
#endif /*LODEPNG_COMPILE_UNKNOWN_CHUNKS*/
}

unsigned LodePNG_InfoPng_copy(LodePNG_InfoPng* dest, const LodePNG_InfoPng* source)
{
  unsigned error = 0;
  LodePNG_InfoPng_cleanup(dest);
  *dest = *source;
  LodePNG_InfoColor_init(&dest->color);
  error = LodePNG_InfoColor_copy(&dest->color, &source->color); if(error) return error;
  
#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS
  error = LodePNG_Text_copy(&dest->text, &source->text); if(error) return error;
  error = LodePNG_IText_copy(&dest->itext, &source->itext); if(error) return error;
#endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/
  
#ifdef LODEPNG_COMPILE_UNKNOWN_CHUNKS
  LodePNG_UnknownChunks_init(&dest->unknown_chunks);
  error = LodePNG_UnknownChunks_copy(&dest->unknown_chunks, &source->unknown_chunks); if(error) return error;
#endif /*LODEPNG_COMPILE_UNKNOWN_CHUNKS*/
  return error;
}

void LodePNG_InfoPng_swap(LodePNG_InfoPng* a, LodePNG_InfoPng* b)
{
  LodePNG_InfoPng temp = *a;
  *a = *b;
  *b = temp;
}

unsigned LodePNG_InfoColor_copy(LodePNG_InfoColor* dest, const LodePNG_InfoColor* source)
{
  size_t i;
  LodePNG_InfoColor_cleanup(dest);
  *dest = *source;
  dest->palette = (unsigned char*)malloc(source->palettesize * 4);
  if(!dest->palette && source->palettesize) return 9935;
  for(i = 0; i < source->palettesize * 4; i++) dest->palette[i] = source->palette[i];
  return 0;
}

void LodePNG_InfoRaw_init(LodePNG_InfoRaw* info)
{
  LodePNG_InfoColor_init(&info->color);
}

void LodePNG_InfoRaw_cleanup(LodePNG_InfoRaw* info)
{
  LodePNG_InfoColor_cleanup(&info->color);
}

unsigned LodePNG_InfoRaw_copy(LodePNG_InfoRaw* dest, const LodePNG_InfoRaw* source)
{
  unsigned error = 0;
  LodePNG_InfoRaw_cleanup(dest);
  *dest = *source;
  LodePNG_InfoColor_init(&dest->color);
  error = LodePNG_InfoColor_copy(&dest->color, &source->color); if(error) return error;
  return error;
}

/* ////////////////////////////////////////////////////////////////////////// */

/*
converts from any color type to 24-bit or 32-bit (later maybe more supported). return value = LodePNG error code
the out buffer must have (w * h * bpp + 7) / 8 bytes, where bpp is the bits per pixel of the output color type (LodePNG_InfoColor_getBpp)
for < 8 bpp images, there may _not_ be padding bits at the end of scanlines.
*/
unsigned LodePNG_convert(unsigned char* out, const unsigned char* in, LodePNG_InfoColor* infoOut, LodePNG_InfoColor* infoIn, unsigned w, unsigned h)
{
  const size_t numpixels = w * h; /*amount of pixels*/
  const unsigned OUT_BYTES = LodePNG_InfoColor_getBpp(infoOut) / 8; /*bytes per pixel in the output image*/
  const unsigned OUT_ALPHA = LodePNG_InfoColor_isAlphaType(infoOut); /*use 8-bit alpha channel*/
  size_t i, c, bp = 0; /*bitpointer, used by less-than-8-bit color types*/
  
  /*cases where in and out already have the same format*/
  if(LodePNG_InfoColor_equal(infoIn, infoOut))
  {
    size_t i, size = (w * h * LodePNG_InfoColor_getBpp(infoIn) + 7) / 8;
    for(i = 0; i < size; i++) out[i] = in[i];
    return 0;
  }

  if((infoOut->colorType == 2 || infoOut->colorType == 6) && infoOut->bitDepth == 8)
  {
    if(infoIn->bitDepth == 8)
    {
      switch(infoIn->colorType)
      {
        case 0: /*greyscale color*/
          for(i = 0; i < numpixels; i++)
          {
            if(OUT_ALPHA) out[OUT_BYTES * i + 3] = 255;
            out[OUT_BYTES * i + 0] = out[OUT_BYTES * i + 1] = out[OUT_BYTES * i + 2] = in[i];
            if(OUT_ALPHA && infoIn->key_defined && in[i] == infoIn->key_r) out[OUT_BYTES * i + 3] = 0;
          }
        break;
        case 2: /*RGB color*/
          for(i = 0; i < numpixels; i++)
          {
            if(OUT_ALPHA) out[OUT_BYTES * i + 3] = 255;
            for(c = 0; c < 3; c++) out[OUT_BYTES * i + c] = in[3 * i + c];
            if(OUT_ALPHA && infoIn->key_defined == 1 && in[3 * i + 0] == infoIn->key_r && in[3 * i + 1] == infoIn->key_g && in[3 * i + 2] == infoIn->key_b) out[OUT_BYTES * i + 3] = 0;
          }
        break;
        case 3: /*indexed color (palette)*/
          for(i = 0; i < numpixels; i++)
          {
            if(OUT_ALPHA) out[OUT_BYTES * i + 3] = 255;
            if(in[i] >= infoIn->palettesize) return 46;
            for(c = 0; c < OUT_BYTES; c++) out[OUT_BYTES * i + c] = infoIn->palette[4 * in[i] + c]; /*get rgb colors from the palette*/
          }
        break;
        case 4: /*greyscale with alpha*/
          for(i = 0; i < numpixels; i++)
          {
            out[OUT_BYTES * i + 0] = out[OUT_BYTES * i + 1] = out[OUT_BYTES * i + 2] = in[2 * i + 0];
            if(OUT_ALPHA) out[OUT_BYTES * i + 3] = in[2 * i + 1];
          }
        break;
        case 6: /*RGB with alpha*/
          for(i = 0; i < numpixels; i++)
          {
            for(c = 0; c < OUT_BYTES; c++) out[OUT_BYTES * i + c] = in[4 * i + c];
          }
        break;
        default: break;
      }
    }
    else if(infoIn->bitDepth == 16)
    {
      switch(infoIn->colorType)
      {
        case 0: /*greyscale color*/
          for(i = 0; i < numpixels; i++)
          {
            if(OUT_ALPHA) out[OUT_BYTES * i + 3] = 255;
            out[OUT_BYTES * i + 0] = out[OUT_BYTES * i + 1] = out[OUT_BYTES * i + 2] = in[2 * i];
            if(OUT_ALPHA && infoIn->key_defined && 256U * in[i] + in[i + 1] == infoIn->key_r) out[OUT_BYTES * i + 3] = 0;
          }
        break;
        case 2: /*RGB color*/
          for(i = 0; i < numpixels; i++)
          {
            if(OUT_ALPHA) out[OUT_BYTES * i + 3] = 255;
            for(c = 0; c < 3; c++) out[OUT_BYTES * i + c] = in[6 * i + 2 * c];
            if(OUT_ALPHA && infoIn->key_defined && 256U * in[6 * i + 0] + in[6 * i + 1] == infoIn->key_r && 256U * in[6 * i + 2] + in[6 * i + 3] == infoIn->key_g && 256U * in[6 * i + 4] + in[6 * i + 5] == infoIn->key_b) out[OUT_BYTES * i + 3] = 0;
          }
        break;
        case 4: /*greyscale with alpha*/
          for(i = 0; i < numpixels; i++)
          {
            out[OUT_BYTES * i + 0] = out[OUT_BYTES * i + 1] = out[OUT_BYTES * i + 2] = in[4 * i]; /*most significant byte*/
            if(OUT_ALPHA) out[OUT_BYTES * i + 3] = in[4 * i + 2];
          }
        break;
        case 6: /*RGB with alpha*/
          for(i = 0; i < numpixels; i++)
          {
            for(c = 0; c < OUT_BYTES; c++) out[OUT_BYTES * i + c] = in[8 * i + 2 * c];
          }
          break;
        default: break;
      }
    }
    else /*infoIn->bitDepth is less than 8 bit per channel*/
    {
      switch(infoIn->colorType)
      {
        case 0: /*greyscale color*/
          for(i = 0; i < numpixels; i++)
          {
            unsigned value = readBitsFromReversedStream(&bp, in, infoIn->bitDepth);
            if(OUT_ALPHA) out[OUT_BYTES * i + 3] = 255;
            if(OUT_ALPHA && infoIn->key_defined && value && ((1U << infoIn->bitDepth) - 1U) == infoIn->key_r && ((1U << infoIn->bitDepth) - 1U)) out[OUT_BYTES * i + 3] = 0;
            value = (value * 255) / ((1 << infoIn->bitDepth) - 1); /*scale value from 0 to 255*/
            out[OUT_BYTES * i + 0] = out[OUT_BYTES * i + 1] = out[OUT_BYTES * i + 2] = (unsigned char)(value);
          }
        break;
        case 3: /*indexed color (palette)*/
          for(i = 0; i < numpixels; i++)
          {
            unsigned value = readBitsFromReversedStream(&bp, in, infoIn->bitDepth);
            if(OUT_ALPHA) out[OUT_BYTES * i + 3] = 255;
            if(value >= infoIn->palettesize) return 47;
            for(c = 0; c < OUT_BYTES; c++) out[OUT_BYTES * i + c] = infoIn->palette[4 * value + c]; /*get rgb colors from the palette*/
          }
        break;
        default: break;
      }
    }
  }
  else if(LodePNG_InfoColor_isGreyscaleType(infoOut) && infoOut->bitDepth == 8) /*conversion from greyscale to greyscale*/
  {
    if(!LodePNG_InfoColor_isGreyscaleType(infoIn)) return 62;
    if(infoIn->bitDepth == 8)
    {
      switch(infoIn->colorType)
      {
        case 0: /*greyscale color*/
          for(i = 0; i < numpixels; i++)
          {
            if(OUT_ALPHA) out[OUT_BYTES * i + 1] = 255;
            out[OUT_BYTES * i] = in[i];
            if(OUT_ALPHA && infoIn->key_defined && in[i] == infoIn->key_r) out[OUT_BYTES * i + 1] = 0;
          }
        break;
        case 4: /*greyscale with alpha*/
          for(i = 0; i < numpixels; i++)
          {
            out[OUT_BYTES * i + 0] = in[2 * i + 0];
            if(OUT_ALPHA) out[OUT_BYTES * i + 1] = in[2 * i + 1];
          }
        break;
        default: return 31;
      }
    }
    else if(infoIn->bitDepth == 16)
    {
      switch(infoIn->colorType)
      {
        case 0: /*greyscale color*/
          for(i = 0; i < numpixels; i++)
          {
            if(OUT_ALPHA) out[OUT_BYTES * i + 1] = 255;
            out[OUT_BYTES * i] = in[2 * i];
            if(OUT_ALPHA && infoIn->key_defined && 256U * in[i] + in[i + 1] == infoIn->key_r) out[OUT_BYTES * i + 1] = 0;
          }
        break;
        case 4: /*greyscale with alpha*/
          for(i = 0; i < numpixels; i++)
          {
            out[OUT_BYTES * i] = in[4 * i]; /*most significant byte*/
            if(OUT_ALPHA) out[OUT_BYTES * i + 1] = in[4 * i + 2]; /*most significant byte*/
          }
        break;
        default: return 31;
      }
    }
    else /*infoIn->bitDepth is less than 8 bit per channel*/
    {
      if(infoIn->colorType != 0) return 31; /*colorType 0 is the only greyscale type with < 8 bits per channel*/
      for(i = 0; i < numpixels; i++)
      {
        unsigned value = readBitsFromReversedStream(&bp, in, infoIn->bitDepth);
        if(OUT_ALPHA) out[OUT_BYTES * i + 1] = 255;
        if(OUT_ALPHA && infoIn->key_defined && value && ((1U << infoIn->bitDepth) - 1U) == infoIn->key_r && ((1U << infoIn->bitDepth) - 1U)) out[OUT_BYTES * i + 1] = 0;
        value = (value * 255) / ((1 << infoIn->bitDepth) - 1); /*scale value from 0 to 255*/
        out[OUT_BYTES * i] = (unsigned char)(value);
      }
    }
  }
  else return 59;
  
  return 0;
}

/*Paeth predicter, used by PNG filter type 4*/
static int paethPredictor(int a, int b, int c)
{
  int p = a + b - c;
  int pa = p > a ? p - a : a - p;
  int pb = p > b ? p - b : b - p;
  int pc = p > c ? p - c : c - p;
  
  if(pa <= pb && pa <= pc) return a;
  else if(pb <= pc) return b;
  else return c;
}

/*shared values used by multiple Adam7 related functions*/

static const unsigned ADAM7_IX[7] = { 0, 4, 0, 2, 0, 1, 0 }; /*x start values*/
static const unsigned ADAM7_IY[7] = { 0, 0, 4, 0, 2, 0, 1 }; /*y start values*/
static const unsigned ADAM7_DX[7] = { 8, 8, 4, 4, 2, 2, 1 }; /*x delta values*/
static const unsigned ADAM7_DY[7] = { 8, 8, 8, 4, 4, 2, 2 }; /*y delta values*/

static void Adam7_getpassvalues(unsigned passw[7], unsigned passh[7], size_t filter_passstart[8], size_t padded_passstart[8], size_t passstart[8], unsigned w, unsigned h, unsigned bpp)
{
  /*the passstart values have 8 values: the 8th one actually indicates the byte after the end of the 7th (= last) pass*/
  unsigned i;
  
  /*calculate width and height in pixels of each pass*/
  for(i = 0; i < 7; i++)
  {
    passw[i] = (w + ADAM7_DX[i] - ADAM7_IX[i] - 1) / ADAM7_DX[i];
    passh[i] = (h + ADAM7_DY[i] - ADAM7_IY[i] - 1) / ADAM7_DY[i];
    if(passw[i] == 0) passh[i] = 0;
    if(passh[i] == 0) passw[i] = 0;
  }
  
  filter_passstart[0] = padded_passstart[0] = passstart[0] = 0;
  for(i = 0; i < 7; i++)
  {
    filter_passstart[i + 1] = filter_passstart[i] + ((passw[i] && passh[i]) ? passh[i] * (1 + (passw[i] * bpp + 7) / 8) : 0); /*if passw[i] is 0, it's 0 bytes, not 1 (no filtertype-byte)*/
    padded_passstart[i + 1] = padded_passstart[i] + passh[i] * ((passw[i] * bpp + 7) / 8); /*bits padded if needed to fill full byte at end of each scanline*/
    passstart[i + 1] = passstart[i] + (passh[i] * passw[i] * bpp + 7) / 8; /*only padded at end of reduced image*/
  }
}

#ifdef LODEPNG_COMPILE_DECODER

/* ////////////////////////////////////////////////////////////////////////// */
/* / PNG Decoder                                                            / */
/* ////////////////////////////////////////////////////////////////////////// */

/*read the information from the header and store it in the LodePNG_Info. return value is error*/
void LodePNG_inspect(LodePNG_Decoder* decoder, const unsigned char* in, size_t inlength)
{
  if(inlength == 0 || in == 0) { decoder->error = 48; return; } /*the given data is empty*/
  if(inlength < 29) { decoder->error = 27; return; } /*error: the data length is smaller than the length of the header*/
  
  /*when decoding a new PNG image, make sure all parameters created after previous decoding are reset*/
  LodePNG_InfoPng_cleanup(&decoder->infoPng);
  LodePNG_InfoPng_init(&decoder->infoPng);
  decoder->error = 0;

  if(in[0] != 137 || in[1] != 80 || in[2] != 78 || in[3] != 71 || in[4] != 13 || in[5] != 10 || in[6] != 26 || in[7] != 10) { decoder->error = 28; return; } /*error: the first 8 bytes are not the correct PNG signature*/
  if(in[12] != 'I' || in[13] != 'H' || in[14] != 'D' || in[15] != 'R') { decoder->error = 29; return; } /*error: it doesn't start with a IHDR chunk!*/
  
  /*read the values given in the header*/
  decoder->infoPng.width = LodePNG_read32bitInt(&in[16]);
  decoder->infoPng.height = LodePNG_read32bitInt(&in[20]);
  decoder->infoPng.color.bitDepth = in[24];
  decoder->infoPng.color.colorType = in[25];
  decoder->infoPng.compressionMethod = in[26];
  decoder->infoPng.filterMethod = in[27];
  decoder->infoPng.interlaceMethod = in[28];

  if(!decoder->settings.ignoreCrc)
  {
    unsigned CRC = LodePNG_read32bitInt(&in[29]);
    unsigned checksum = Crc32_crc(&in[12], 17);
    if(CRC != checksum) { decoder->error = 57; return; }
  }
  
  if(decoder->infoPng.compressionMethod != 0) { decoder->error = 32; return; } /*error: only compression method 0 is allowed in the specification*/
  if(decoder->infoPng.filterMethod != 0)      { decoder->error = 33; return; } /*error: only filter method 0 is allowed in the specification*/
  if(decoder->infoPng.interlaceMethod > 1)    { decoder->error = 34; return; } /*error: only interlace methods 0 and 1 exist in the specification*/
  
  decoder->error = checkColorValidity(decoder->infoPng.color.colorType, decoder->infoPng.color.bitDepth);
}

static unsigned unfilterScanline(unsigned char* recon, const unsigned char* scanline, const unsigned char* precon, size_t bytewidth, unsigned char filterType, size_t length)
{
  /*
  For PNG filter method 0
  unfilter a PNG image scanline by scanline. when the pixels are smaller than 1 byte, the filter works byte per byte (bytewidth = 1)
  precon is the previous unfiltered scanline, recon the result, scanline the current one
  the incoming scanlines do NOT include the filtertype byte, that one is given in the parameter filterType instead
  recon and scanline MAY be the same memory address! precon must be disjoint.
  */
  
  size_t i;
  switch(filterType)
  {
    case 0:
      for(i = 0; i < length; i++) recon[i] = scanline[i];
      break;
    case 1:
      for(i =         0; i < bytewidth; i++) recon[i] = scanline[i];
      for(i = bytewidth; i <    length; i++) recon[i] = scanline[i] + recon[i - bytewidth];
      break;
    case 2: 
      if(precon) for(i = 0; i < length; i++) recon[i] = scanline[i] + precon[i];
      else       for(i = 0; i < length; i++) recon[i] = scanline[i];
      break;
    case 3:
      if(precon)
      {
        for(i =         0; i < bytewidth; i++) recon[i] = scanline[i] + precon[i] / 2;
        for(i = bytewidth; i <    length; i++) recon[i] = scanline[i] + ((recon[i - bytewidth] + precon[i]) / 2);
      }
      else
      {
        for(i =         0; i < bytewidth; i++) recon[i] = scanline[i];
        for(i = bytewidth; i <    length; i++) recon[i] = scanline[i] + recon[i - bytewidth] / 2;
      }
      break;
    case 4:
      if(precon)
      {
        for(i =         0; i < bytewidth; i++) recon[i] = (unsigned char)(scanline[i] + paethPredictor(0, precon[i], 0));
        for(i = bytewidth; i <    length; i++) recon[i] = (unsigned char)(scanline[i] + paethPredictor(recon[i - bytewidth], precon[i], precon[i - bytewidth]));
      }
      else
      {
        for(i =         0; i < bytewidth; i++) recon[i] = scanline[i];
        for(i = bytewidth; i <    length; i++) recon[i] = (unsigned char)(scanline[i] + paethPredictor(recon[i - bytewidth], 0, 0));
      }
      break;
    default: return 36; /*error: unexisting filter type given*/
  }
  return 0;
}

static unsigned unfilter(unsigned char* out, const unsigned char* in, unsigned w, unsigned h, unsigned bpp)
{
  /*
  For PNG filter method 0
  this function unfilters a single image (e.g. without interlacing this is called once, with Adam7 it's called 7 times)
  out must have enough bytes allocated already, in must have the scanlines + 1 filtertype byte per scanline
  w and h are image dimensions or dimensions of reduced image, bpp is bits per pixel
  in and out are allowed to be the same memory address!
  */
  
  unsigned y;
  unsigned char* prevline = 0;
  
  size_t bytewidth = (bpp + 7) / 8; /*bytewidth is used for filtering, is 1 when bpp < 8, number of bytes per pixel otherwise*/
  size_t linebytes = (w * bpp + 7) / 8;
  
  for(y = 0; y < h; y++)
  {
    size_t outindex = linebytes * y;
    size_t inindex = (1 + linebytes) * y; /*the extra filterbyte added to each row*/
    unsigned char filterType = in[inindex];
    
    unsigned error = unfilterScanline(&out[outindex], &in[inindex + 1], prevline, bytewidth, filterType, linebytes);
    if(error) return error;
    
    prevline = &out[outindex];
  }
  
  return 0;
}

static void Adam7_deinterlace(unsigned char* out, const unsigned char* in, unsigned w, unsigned h, unsigned bpp)
{
  /*Note: this function works on image buffers WITHOUT padding bits at end of scanlines with non-multiple-of-8 bit amounts, only between reduced images is padding
  out must be big enough AND must be 0 everywhere if bpp < 8 in the current implementation (because that's likely a little bit faster)*/
  unsigned passw[7], passh[7]; size_t filter_passstart[8], padded_passstart[8], passstart[8];
  unsigned i;

  Adam7_getpassvalues(passw, passh, filter_passstart, padded_passstart, passstart, w, h, bpp);
  
  if(bpp >= 8)
  {
    for(i = 0; i < 7; i++)
    {
      unsigned x, y, b;
      size_t bytewidth = bpp / 8;
      for(y = 0; y < passh[i]; y++)
      for(x = 0; x < passw[i]; x++)
      {
        size_t pixelinstart = passstart[i] + (y * passw[i] + x) * bytewidth;
        size_t pixeloutstart = ((ADAM7_IY[i] + y * ADAM7_DY[i]) * w + ADAM7_IX[i] + x * ADAM7_DX[i]) * bytewidth;
        for(b = 0; b < bytewidth; b++)
        {
          out[pixeloutstart + b] = in[pixelinstart + b];
        }
      }
    }
  }
  else /*bpp < 8: Adam7 with pixels < 8 bit is a bit trickier: with bit pointers*/
  {
    for(i = 0; i < 7; i++)
    {
      unsigned x, y, b;
      unsigned ilinebits = bpp * passw[i];
      unsigned olinebits = bpp * w;
      size_t obp, ibp; /*bit pointers (for out and in buffer)*/
      for(y = 0; y < passh[i]; y++)
      for(x = 0; x < passw[i]; x++)
      {
        ibp = (8 * passstart[i]) + (y * ilinebits + x * bpp);
        obp = (ADAM7_IY[i] + y * ADAM7_DY[i]) * olinebits + (ADAM7_IX[i] + x * ADAM7_DX[i]) * bpp;
        for(b = 0; b < bpp; b++)
        {
          unsigned char bit = readBitFromReversedStream(&ibp, in);
          setBitOfReversedStream0(&obp, out, bit); /*note that this function assumes the out buffer is completely 0, use setBitOfReversedStream otherwise*/
        }
      }
    }
  }
}

static void removePaddingBits(unsigned char* out, const unsigned char* in, size_t olinebits, size_t ilinebits, unsigned h)
{
  /*
  After filtering there are still padding bits if scanlines have non multiple of 8 bit amounts. They need to be removed (except at last scanline of (Adam7-reduced) image) before working with pure image buffers for the Adam7 code, the color convert code and the output to the user.
  in and out are allowed to be the same buffer, in may also be higher but still overlapping; in must have >= ilinebits*h bits, out must have >= olinebits*h bits, olinebits must be <= ilinebits
  also used to move bits after earlier such operations happened, e.g. in a sequence of reduced images from Adam7
  only useful if (ilinebits - olinebits) is a value in the range 1..7
  */
  unsigned y;
  size_t diff = ilinebits - olinebits;
  size_t obp = 0, ibp = 0; /*bit pointers*/
  for(y = 0; y < h; y++)
  {
    size_t x;
    for(x = 0; x < olinebits; x++)
    {
      unsigned char bit = readBitFromReversedStream(&ibp, in);
      setBitOfReversedStream(&obp, out, bit);
    }
    ibp += diff;
  }
}

/*out must be buffer big enough to contain full image, and in must contain the full decompressed data from the IDAT chunks*/
static unsigned postProcessScanlines(unsigned char* out, unsigned char* in, const LodePNG_InfoPng* infoPng) /*return value is error*/
{
  /*
  This function converts the filtered-padded-interlaced data into pure 2D image buffer with the PNG's colortype. Steps:
  *) if no Adam7: 1) unfilter 2) remove padding bits (= posible extra bits per scanline if bpp < 8)
  *) if adam7: 1) 7x unfilter 2) 7x remove padding bits 3) Adam7_deinterlace
  NOTE: the in buffer will be overwritten with intermediate data!
  */
  unsigned bpp = LodePNG_InfoColor_getBpp(&infoPng->color);
  unsigned w = infoPng->width;
  unsigned h = infoPng->height;
  unsigned error = 0;
  if(bpp == 0) return 31; /*error: invalid colortype*/
  
  if(infoPng->interlaceMethod == 0)
  {
    if(bpp < 8 && w * bpp != ((w * bpp + 7) / 8) * 8)
    {
      error = unfilter(in, in, w, h, bpp);
      if(error) return error;
      removePaddingBits(out, in, w * bpp, ((w * bpp + 7) / 8) * 8, h);
    }
    else error = unfilter(out, in, w, h, bpp); /*we can immediatly filter into the out buffer, no other steps needed*/
  }
  else /*interlaceMethod is 1 (Adam7)*/
  {
    unsigned passw[7], passh[7]; size_t filter_passstart[8], padded_passstart[8], passstart[8];
    unsigned i;
    
    Adam7_getpassvalues(passw, passh, filter_passstart, padded_passstart, passstart, w, h, bpp);
    
    for(i = 0; i < 7; i++)
    {
      error = unfilter(&in[padded_passstart[i]], &in[filter_passstart[i]], passw[i], passh[i], bpp);
      if(error) return error;
      if(bpp < 8) /*TODO: possible efficiency improvement: if in this reduced image the bits fit nicely in 1 scanline, move bytes instead of bits or move not at all*/
      {
        /*remove padding bits in scanlines; after this there still may be padding bits between the different reduced images: each reduced image still starts nicely at a byte*/
        removePaddingBits(&in[passstart[i]], &in[padded_passstart[i]], passw[i] * bpp, ((passw[i] * bpp + 7) / 8) * 8, passh[i]);
      }
    }
    
    Adam7_deinterlace(out, in, w, h, bpp);
  }
  
  return error;
}

/*read a PNG, the result will be in the same color type as the PNG (hence "generic")*/
static void decodeGeneric(LodePNG_Decoder* decoder, unsigned char** out, size_t* outsize, const unsigned char* in, size_t size)
{
  unsigned char IEND = 0;
  const unsigned char* chunk;
  size_t i;
  ucvector idat; /*the data from idat chunks*/
  
  /*for unknown chunk order*/
  unsigned unknown = 0;
  unsigned critical_pos = 1; /*1 = after IHDR, 2 = after PLTE, 3 = after IDAT*/
  
  /*provide some proper output values if error will happen*/
  *out = 0;
  *outsize = 0;
  
  if(size == 0 || in == 0) { decoder->error = 48; return; } /*the given data is empty*/

  LodePNG_inspect(decoder, in, size); /*reads header and resets other parameters in decoder->infoPng*/
  if(decoder->error) return;

  ucvector_init(&idat);
  
  chunk = &in[33]; /*first byte of the first chunk after the header*/
  
  while(!IEND) /*loop through the chunks, ignoring unknown chunks and stopping at IEND chunk. IDAT data is put at the start of the in buffer*/
  {
    unsigned chunkLength;
    const unsigned char* data; /*the data in the chunk*/
    
    if((size_t)((chunk - in) + 12) > size || chunk < in) { decoder->error = 30; break; } /*error: size of the in buffer too small to contain next chunk*/
    chunkLength = LodePNG_chunk_length(chunk); /*length of the data of the chunk, excluding the length bytes, chunk type and CRC bytes*/
    if(chunkLength > 2147483647) { decoder->error = 63; break; }
    if((size_t)((chunk - in) + chunkLength + 12) > size || (chunk + chunkLength + 12) < in) { decoder->error = 35; break; } /*error: size of the in buffer too small to contain next chunk*/
    data = LodePNG_chunk_data_const(chunk);
    
    /*IDAT chunk, containing compressed image data*/
    if(LodePNG_chunk_type_equals(chunk, "IDAT"))
    {
      size_t oldsize = idat.size;
      if(!ucvector_resize(&idat, oldsize + chunkLength)) { decoder->error = 9936; break; }
      for(i = 0; i < chunkLength; i++) idat.data[oldsize + i] = data[i];
      critical_pos = 3;
    }
    /*IEND chunk*/
    else if(LodePNG_chunk_type_equals(chunk, "IEND"))
    {
      IEND = 1;
    }
    /*palette chunk (PLTE)*/
    else if(LodePNG_chunk_type_equals(chunk, "PLTE"))
    {
      unsigned pos = 0;
      if(decoder->infoPng.color.palette) free(decoder->infoPng.color.palette);
      decoder->infoPng.color.palettesize = chunkLength / 3;
      decoder->infoPng.color.palette = (unsigned char*)malloc(4 * decoder->infoPng.color.palettesize);
      if(!decoder->infoPng.color.palette && decoder->infoPng.color.palettesize) { decoder->error = 9937; break; }
      if(!decoder->infoPng.color.palette) decoder->infoPng.color.palettesize = 0; /*malloc failed...*/
      if(decoder->infoPng.color.palettesize > 256) { decoder->error = 38; break; } /*error: palette too big*/
      for(i = 0; i < decoder->infoPng.color.palettesize; i++)
      {
        decoder->infoPng.color.palette[4 * i + 0] = data[pos++]; /*R*/
        decoder->infoPng.color.palette[4 * i + 1] = data[pos++]; /*G*/
        decoder->infoPng.color.palette[4 * i + 2] = data[pos++]; /*B*/
        decoder->infoPng.color.palette[4 * i + 3] = 255; /*alpha*/
      }
      critical_pos = 2;
    }
    /*palette transparency chunk (tRNS)*/
    else if(LodePNG_chunk_type_equals(chunk, "tRNS"))
    {
      if(decoder->infoPng.color.colorType == 3)
      {
        if(chunkLength > decoder->infoPng.color.palettesize) { decoder->error = 39; break; } /*error: more alpha values given than there are palette entries*/
        for(i = 0; i < chunkLength; i++) decoder->infoPng.color.palette[4 * i + 3] = data[i];
      }
      else if(decoder->infoPng.color.colorType == 0)
      {
        if(chunkLength != 2) { decoder->error = 40; break; } /*error: this chunk must be 2 bytes for greyscale image*/
        decoder->infoPng.color.key_defined = 1;
        decoder->infoPng.color.key_r = decoder->infoPng.color.key_g = decoder->infoPng.color.key_b = 256 * data[0] + data[1];
      }
      else if(decoder->infoPng.color.colorType == 2)
      {
        if(chunkLength != 6) { decoder->error = 41; break; } /*error: this chunk must be 6 bytes for RGB image*/
        decoder->infoPng.color.key_defined = 1;
        decoder->infoPng.color.key_r = 256 * data[0] + data[1];
        decoder->infoPng.color.key_g = 256 * data[2] + data[3];
        decoder->infoPng.color.key_b = 256 * data[4] + data[5];
      }
      else { decoder->error = 42; break; } /*error: tRNS chunk not allowed for other color models*/
    }
#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS
    /*background color chunk (bKGD)*/
    else if(LodePNG_chunk_type_equals(chunk, "bKGD"))
    {
      if(decoder->infoPng.color.colorType == 3)
      {
        if(chunkLength != 1) { decoder->error = 43; break; } /*error: this chunk must be 1 byte for indexed color image*/
        decoder->infoPng.background_defined = 1;
        decoder->infoPng.background_r = decoder->infoPng.background_g = decoder->infoPng.background_g = data[0];
      }
      else if(decoder->infoPng.color.colorType == 0 || decoder->infoPng.color.colorType == 4)
      {
        if(chunkLength != 2) { decoder->error = 44; break; } /*error: this chunk must be 2 bytes for greyscale image*/
        decoder->infoPng.background_defined = 1;
        decoder->infoPng.background_r = decoder->infoPng.background_g = decoder->infoPng.background_b = 256 * data[0] + data[1];
      }
      else if(decoder->infoPng.color.colorType == 2 || decoder->infoPng.color.colorType == 6)
      {
        if(chunkLength != 6) { decoder->error = 45; break; } /*error: this chunk must be 6 bytes for greyscale image*/
        decoder->infoPng.background_defined = 1;
        decoder->infoPng.background_r = 256 * data[0] + data[1];
        decoder->infoPng.background_g = 256 * data[2] + data[3];
        decoder->infoPng.background_b = 256 * data[4] + data[5];
      }
    }
    /*text chunk (tEXt)*/
    else if(LodePNG_chunk_type_equals(chunk, "tEXt"))
    {
      if(decoder->settings.readTextChunks)
      {
        char *key = 0, *str = 0;
        
        while(!decoder->error) /*not really a while loop, only used to break on error*/
        {
          unsigned length, string2_begin;
          
          for(length = 0; length < chunkLength && data[length] != 0; length++) ;
          if(length + 1 >= chunkLength) { decoder->error = 75; break; }
          key = (char*)malloc(length + 1);
          if(!key) { decoder->error = 9938; break; }
          key[length] = 0;
          for(i = 0; i < length; i++) key[i] = data[i];
  
          string2_begin = length + 1;
          if(string2_begin > chunkLength)  { decoder->error = 75; break; }
          length = chunkLength - string2_begin;
          str = (char*)malloc(length + 1);
          if(!str) { decoder->error = 9939; break; }
          str[length] = 0;
          for(i = 0; i < length; i++) str[i] = data[string2_begin + i];
  
          decoder->error = LodePNG_Text_add(&decoder->infoPng.text, key, str);
          
          break;
        }

        free(key);
        free(str);
      }
    }
    /*compressed text chunk (zTXt)*/
    else if(LodePNG_chunk_type_equals(chunk, "zTXt"))
    {
      if(decoder->settings.readTextChunks)
      {
        unsigned length, string2_begin;
        char *key = 0;
        ucvector decoded;
        
        ucvector_init(&decoded);
        
        while(!decoder->error) /*not really a while loop, only used to break on error*/
        {
          for(length = 0; length < chunkLength && data[length] != 0; length++) ;
          if(length + 2 >= chunkLength) { decoder->error = 75; break; }
          key = (char*)malloc(length + 1);
          if(!key) { decoder->error = 9940; break; }
          key[length] = 0;
          for(i = 0; i < length; i++) key[i] = data[i];
          
          if(data[length + 1] != 0) { decoder->error = 72; break; } /*the 0 byte indicating compression must be 0*/
          
          string2_begin = length + 2;
          if(string2_begin > chunkLength)  { decoder->error = 75; break; }
          length = chunkLength - string2_begin;
          decoder->error = LodePNG_decompress(&decoded.data, &decoded.size, (unsigned char*)(&data[string2_begin]), length, &decoder->settings.zlibsettings);
          if(decoder->error) break;
          ucvector_push_back(&decoded, 0);

          decoder->error = LodePNG_Text_add(&decoder->infoPng.text, key, (char*)decoded.data);
          
          break;
        }

        free(key);
        ucvector_cleanup(&decoded);
        if(decoder->error) break;
      }
    }
    /*international text chunk (iTXt)*/
    else if(LodePNG_chunk_type_equals(chunk, "iTXt"))
    {
      if(decoder->settings.readTextChunks)
      {
        unsigned length, begin, compressed;
        char *key = 0, *langtag = 0, *transkey = 0;
        ucvector decoded;
        ucvector_init(&decoded);
        
        while(!decoder->error) /*not really a while loop, only used to break on error*/
        {
          if(chunkLength < 5) { decoder->error = 76; break; }
          for(length = 0; length < chunkLength && data[length] != 0; length++) ;
          if(length + 2 >= chunkLength) { decoder->error = 75; break; }
          key = (char*)malloc(length + 1);
          if(!key) { decoder->error = 9941; break; }
          key[length] = 0;
          for(i = 0; i < length; i++) key[i] = data[i];
          
          compressed = data[length + 1];
          if(data[length + 2] != 0) { decoder->error = 72; break; } /*the 0 byte indicating compression must be 0*/
          
          begin = length + 3;
          length = 0;
          for(i = begin; i < chunkLength && data[i] != 0; i++) length++;
          if(begin + length + 1 >= chunkLength) { decoder->error = 75; break; }
          langtag = (char*)malloc(length + 1);
          if(!langtag) { decoder->error = 9942; break; }
          langtag[length] = 0;
          for(i = 0; i < length; i++) langtag[i] = data[begin + i];
          
          begin += length + 1;
          length = 0;
          for(i = begin; i < chunkLength && data[i] != 0; i++) length++;
          if(begin + length + 1 >= chunkLength) { decoder->error = 75; break; }
          transkey = (char*)malloc(length + 1);
          if(!transkey) { decoder->error = 9943; break; }
          transkey[length] = 0;
          for(i = 0; i < length; i++) transkey[i] = data[begin + i];

          begin += length + 1;
          if(begin > chunkLength)  { decoder->error = 75; break; }
          length = chunkLength - begin;
          
          if(compressed)
          {
            decoder->error = LodePNG_decompress(&decoded.data, &decoded.size, (unsigned char*)(&data[begin]), length, &decoder->settings.zlibsettings);
            if(decoder->error) break;
            ucvector_push_back(&decoded, 0);
          }
          else
          {
            if(!ucvector_resize(&decoded, length + 1)) { decoder->error = 9944; break; }
            decoded.data[length] = 0;
            for(i = 0; i < length; i++) decoded.data[i] = data[begin + i];
          }
          
          decoder->error = LodePNG_IText_add(&decoder->infoPng.itext, key, langtag, transkey, (char*)decoded.data);
          
          break;
        }

        free(key);
        free(langtag);
        free(transkey);
        ucvector_cleanup(&decoded);
        if(decoder->error) break;
      }
    }
    else if(LodePNG_chunk_type_equals(chunk, "tIME"))
    {
      if(chunkLength != 7) { decoder->error = 73; break; }
      decoder->infoPng.time_defined = 1;
      decoder->infoPng.time.year = 256 * data[0] + data[+ 1];
      decoder->infoPng.time.month = data[2];
      decoder->infoPng.time.day = data[3];
      decoder->infoPng.time.hour = data[4];
      decoder->infoPng.time.minute = data[5];
      decoder->infoPng.time.second = data[6];
    }
    else if(LodePNG_chunk_type_equals(chunk, "pHYs"))
    {
      if(chunkLength != 9) { decoder->error = 74; break; }
      decoder->infoPng.phys_defined = 1;
      decoder->infoPng.phys_x = 16777216 * data[0] + 65536 * data[1] + 256 * data[2] + data[3];
      decoder->infoPng.phys_y = 16777216 * data[4] + 65536 * data[5] + 256 * data[6] + data[7];
      decoder->infoPng.phys_unit = data[8];
    }
#endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/
    else /*it's not an implemented chunk type, so ignore it: skip over the data*/
    {
      if(LodePNG_chunk_critical(chunk)) { decoder->error = 69; break; } /*error: unknown critical chunk (5th bit of first byte of chunk type is 0)*/
      unknown = 1;
#ifdef LODEPNG_COMPILE_UNKNOWN_CHUNKS
      if(decoder->settings.rememberUnknownChunks)
      {
        LodePNG_UnknownChunks* unknown = &decoder->infoPng.unknown_chunks;
        decoder->error = LodePNG_append_chunk(&unknown->data[critical_pos - 1], &unknown->datasize[critical_pos - 1], chunk);
        if(decoder->error) break;
      }
#endif /*LODEPNG_COMPILE_UNKNOWN_CHUNKS*/
    }
    
    if(!decoder->settings.ignoreCrc && !unknown) /*check CRC if wanted, only on known chunk types*/
    {
      if(LodePNG_chunk_check_crc(chunk)) { decoder->error = 57; break; }
    }
    
    if(!IEND) chunk = LodePNG_chunk_next_const(chunk);
  }
  
  if(!decoder->error)
  {
    ucvector scanlines;
    ucvector_init(&scanlines);
    if(!ucvector_resize(&scanlines, ((decoder->infoPng.width * (decoder->infoPng.height * LodePNG_InfoColor_getBpp(&decoder->infoPng.color) + 7)) / 8) + decoder->infoPng.height)) decoder->error = 9945; /*maximum final image length is already reserved in the vector's length - this is not really necessary*/
    if(!decoder->error) decoder->error = LodePNG_decompress(&scanlines.data, &scanlines.size, idat.data, idat.size, &decoder->settings.zlibsettings); /*decompress with the Zlib decompressor*/
    
    if(!decoder->error)
    {
      ucvector outv;
      ucvector_init(&outv);
      if(!ucvector_resizev(&outv, (decoder->infoPng.height * decoder->infoPng.width * LodePNG_InfoColor_getBpp(&decoder->infoPng.color) + 7) / 8, 0)) decoder->error = 9946;
      if(!decoder->error) decoder->error = postProcessScanlines(outv.data, scanlines.data, &decoder->infoPng);
      *out = outv.data;
      *outsize = outv.size;
    }
    ucvector_cleanup(&scanlines);
  }
  
  ucvector_cleanup(&idat);
}

void LodePNG_decode(LodePNG_Decoder* decoder, unsigned char** out, size_t* outsize, const unsigned char* in, size_t insize)
{
  *out = 0;
  *outsize = 0;
  decodeGeneric(decoder, out, outsize, in, insize);
  if(decoder->error) return;
  if(!decoder->settings.color_convert || LodePNG_InfoColor_equal(&decoder->infoRaw.color, &decoder->infoPng.color))
  {
    /*same color type, no copying or converting of data needed*/
    /*store the infoPng color settings on the infoRaw so that the infoRaw still reflects what colorType
    the raw image has to the end user*/
    if(!decoder->settings.color_convert)
    {
      decoder->error = LodePNG_InfoColor_copy(&decoder->infoRaw.color, &decoder->infoPng.color);
      if(decoder->error) return;
    }
  }
  else
  {
    /*color conversion needed; sort of copy of the data*/
    unsigned char* data = *out;

    /*TODO: check if this works according to the statement in the documentation: "The converter can convert from greyscale input color type, to 8-bit greyscale or greyscale with alpha"*/
    if(!(decoder->infoRaw.color.colorType == 2 || decoder->infoRaw.color.colorType == 6) && !(decoder->infoRaw.color.bitDepth == 8)) { decoder->error = 56; return; }

    *outsize = (decoder->infoPng.width * decoder->infoPng.height * LodePNG_InfoColor_getBpp(&decoder->infoRaw.color) + 7) / 8;
    *out = (unsigned char*)malloc(*outsize);
    if(!(*out))
    {
      decoder->error = 9947;
      *outsize = 0;
    }
    else decoder->error = LodePNG_convert(*out, data, &decoder->infoRaw.color, &decoder->infoPng.color, decoder->infoPng.width, decoder->infoPng.height);
    free(data);
  }
}

unsigned LodePNG_decode32(unsigned char** out, unsigned* w, unsigned* h, const unsigned char* in, size_t insize)
{
  unsigned error;
  size_t dummy_size;
  LodePNG_Decoder decoder;
  LodePNG_Decoder_init(&decoder);
  LodePNG_decode(&decoder, out, &dummy_size, in, insize);
  error = decoder.error;
  *w = decoder.infoPng.width;
  *h = decoder.infoPng.height;
  LodePNG_Decoder_cleanup(&decoder);
  return error;
}

#ifdef LODEPNG_COMPILE_DISK
unsigned LodePNG_decode32f(unsigned char** out, unsigned* w, unsigned* h, const char* filename)
{
  unsigned char* buffer;
  size_t buffersize;
  unsigned error;
  error = LodePNG_loadFile(&buffer, &buffersize, filename);
  if(!error) error = LodePNG_decode32(out, w, h, buffer, buffersize);
  free(buffer);
  return error;
}
#endif /*LODEPNG_COMPILE_DISK*/

void LodePNG_DecodeSettings_init(LodePNG_DecodeSettings* settings)
{
  settings->color_convert = 1;
#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS
  settings->readTextChunks = 1;
#endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/
  settings->ignoreCrc = 0;
#ifdef LODEPNG_COMPILE_UNKNOWN_CHUNKS
  settings->rememberUnknownChunks = 0;
#endif /*LODEPNG_COMPILE_UNKNOWN_CHUNKS*/
  LodeZlib_DecompressSettings_init(&settings->zlibsettings);
}

void LodePNG_Decoder_init(LodePNG_Decoder* decoder)
{
  LodePNG_DecodeSettings_init(&decoder->settings);
  LodePNG_InfoRaw_init(&decoder->infoRaw);
  LodePNG_InfoPng_init(&decoder->infoPng);
  decoder->error = 1;
}

void LodePNG_Decoder_cleanup(LodePNG_Decoder* decoder)
{
  LodePNG_InfoRaw_cleanup(&decoder->infoRaw);
  LodePNG_InfoPng_cleanup(&decoder->infoPng);
}

void LodePNG_Decoder_copy(LodePNG_Decoder* dest, const LodePNG_Decoder* source)
{
  LodePNG_Decoder_cleanup(dest);
  *dest = *source;
  LodePNG_InfoRaw_init(&dest->infoRaw);
  LodePNG_InfoPng_init(&dest->infoPng);
  dest->error = LodePNG_InfoRaw_copy(&dest->infoRaw, &source->infoRaw); if(dest->error) return;
  dest->error = LodePNG_InfoPng_copy(&dest->infoPng, &source->infoPng); if(dest->error) return;
}

#endif /*LODEPNG_COMPILE_DECODER*/

#ifdef LODEPNG_COMPILE_ENCODER

/* ////////////////////////////////////////////////////////////////////////// */
/* / PNG Encoder                                                            / */
/* ////////////////////////////////////////////////////////////////////////// */

/*chunkName must be string of 4 characters*/
static unsigned addChunk(ucvector* out, const char* chunkName, const unsigned char* data, size_t length)
{
  unsigned error = LodePNG_create_chunk(&out->data, &out->size, (unsigned)length, chunkName, data);
  if(error) return error;
  out->allocsize = out->size; /*fix the allocsize again*/
  return 0;
}

static void writeSignature(ucvector* out)
{
  /*8 bytes PNG signature*/
  ucvector_push_back(out, 137);
  ucvector_push_back(out, 80);
  ucvector_push_back(out, 78);
  ucvector_push_back(out, 71);
  ucvector_push_back(out, 13);
  ucvector_push_back(out, 10);
  ucvector_push_back(out, 26);
  ucvector_push_back(out, 10);
}

static unsigned addChunk_IHDR(ucvector* out, unsigned w, unsigned h, unsigned bitDepth, unsigned colorType, unsigned interlaceMethod)
{
  unsigned error = 0;
  ucvector header;
  ucvector_init(&header);
  
  LodePNG_add32bitInt(&header, w); /*width*/
  LodePNG_add32bitInt(&header, h); /*height*/
  ucvector_push_back(&header, (unsigned char)bitDepth); /*bit depth*/
  ucvector_push_back(&header, (unsigned char)colorType); /*color type*/
  ucvector_push_back(&header, 0); /*compression method*/
  ucvector_push_back(&header, 0); /*filter method*/
  ucvector_push_back(&header, interlaceMethod); /*interlace method*/
  
  error = addChunk(out, "IHDR", header.data, header.size);
  ucvector_cleanup(&header);
  
  return error;
}

static unsigned addChunk_PLTE(ucvector* out, const LodePNG_InfoColor* info)
{
  unsigned error = 0;
  size_t i;
  ucvector PLTE;
  ucvector_init(&PLTE);
  for(i = 0; i < info->palettesize * 4; i++) if(i % 4 != 3) ucvector_push_back(&PLTE, info->palette[i]); /*add all channels except alpha channel*/
  error = addChunk(out, "PLTE", PLTE.data, PLTE.size);
  ucvector_cleanup(&PLTE);
  
  return error;
}

static unsigned addChunk_tRNS(ucvector* out, const LodePNG_InfoColor* info)
{
  unsigned error = 0;
  size_t i;
  ucvector tRNS;
  ucvector_init(&tRNS);
  if(info->colorType == 3)
  {
    for(i = 0; i < info->palettesize; i++) ucvector_push_back(&tRNS, info->palette[4 * i + 3]); /*add only alpha channel*/
  }
  else if(info->colorType == 0)
  {
    if(info->key_defined)
    {
      ucvector_push_back(&tRNS, (unsigned char)(info->key_r / 256));
      ucvector_push_back(&tRNS, (unsigned char)(info->key_r % 256));
    }
  }
  else if(info->colorType == 2)
  {
    if(info->key_defined)
    {
      ucvector_push_back(&tRNS, (unsigned char)(info->key_r / 256));
      ucvector_push_back(&tRNS, (unsigned char)(info->key_r % 256));
      ucvector_push_back(&tRNS, (unsigned char)(info->key_g / 256));
      ucvector_push_back(&tRNS, (unsigned char)(info->key_g % 256));
      ucvector_push_back(&tRNS, (unsigned char)(info->key_b / 256));
      ucvector_push_back(&tRNS, (unsigned char)(info->key_b % 256));
    }
  }
  
  error = addChunk(out, "tRNS", tRNS.data, tRNS.size);
  ucvector_cleanup(&tRNS);
  
  return error;
}

static unsigned addChunk_IDAT(ucvector* out, const unsigned char* data, size_t datasize, LodeZlib_DeflateSettings* zlibsettings)
{
  ucvector zlibdata;
  unsigned error = 0;
  
  /*compress with the Zlib compressor*/
  ucvector_init(&zlibdata);
  error = LodePNG_compress(&zlibdata.data, &zlibdata.size, data, datasize, zlibsettings);
  if(!error) error = addChunk(out, "IDAT", zlibdata.data, zlibdata.size);
  ucvector_cleanup(&zlibdata);
  
  return error;
}

static unsigned addChunk_IEND(ucvector* out)
{
  unsigned error = 0;
  error = addChunk(out, "IEND", 0, 0);
  return error;
}

#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS

static unsigned addChunk_tEXt(ucvector* out, const char* keyword, const char* textstring) /*add text chunk*/
{
  unsigned error = 0;
  size_t i;
  ucvector text;
  ucvector_init(&text);
  for(i = 0; keyword[i] != 0; i++) ucvector_push_back(&text, (unsigned char)keyword[i]);
  ucvector_push_back(&text, 0);
  for(i = 0; textstring[i] != 0; i++) ucvector_push_back(&text, (unsigned char)textstring[i]);
  error = addChunk(out, "tEXt", text.data, text.size);
  ucvector_cleanup(&text);
  
  return error;
}

static unsigned addChunk_zTXt(ucvector* out, const char* keyword, const char* textstring, LodeZlib_DeflateSettings* zlibsettings)
{
  unsigned error = 0;
  ucvector data, compressed;
  size_t i, textsize = strlen(textstring);
  
  ucvector_init(&data);
  ucvector_init(&compressed);
  for(i = 0; keyword[i] != 0; i++) ucvector_push_back(&data, (unsigned char)keyword[i]);
  ucvector_push_back(&data, 0); /* 0 termination char*/
  ucvector_push_back(&data, 0); /*compression method: 0*/
  
  error = LodePNG_compress(&compressed.data, &compressed.size, (unsigned char*)textstring, textsize, zlibsettings);
  if(!error)
  {
    for(i = 0; i < compressed.size; i++) ucvector_push_back(&data, compressed.data[i]);
    error = addChunk(out, "zTXt", data.data, data.size);
  }
  
  ucvector_cleanup(&compressed);
  ucvector_cleanup(&data);
  return error;
}

static unsigned addChunk_iTXt(ucvector* out, unsigned compressed, const char* keyword, const char* langtag, const char* transkey, const char* textstring, LodeZlib_DeflateSettings* zlibsettings)
{
  unsigned error = 0;
  ucvector data, compressed_data;
  size_t i, textsize = strlen(textstring);
  
  ucvector_init(&data);
  
  for(i = 0; keyword[i] != 0; i++) ucvector_push_back(&data, (unsigned char)keyword[i]);
  ucvector_push_back(&data, 0); /*null termination char*/
  ucvector_push_back(&data, compressed ? 1 : 0); /*compression flag*/
  ucvector_push_back(&data, 0); /*compression method*/
  for(i = 0; langtag[i] != 0; i++) ucvector_push_back(&data, (unsigned char)langtag[i]);
  ucvector_push_back(&data, 0); /*null termination char*/
  for(i = 0; transkey[i] != 0; i++) ucvector_push_back(&data, (unsigned char)transkey[i]);
  ucvector_push_back(&data, 0); /*null termination char*/
    
  if(compressed)
  {
    ucvector_init(&compressed_data);
    error = LodePNG_compress(&compressed_data.data, &compressed_data.size, (unsigned char*)textstring, textsize, zlibsettings);
    if(!error)
    {
      for(i = 0; i < compressed_data.size; i++) ucvector_push_back(&data, compressed_data.data[i]);
      for(i = 0; textstring[i] != 0; i++) ucvector_push_back(&data, (unsigned char)textstring[i]);
    }
  }
  else /*not compressed*/
  {
    for(i = 0; textstring[i] != 0; i++) ucvector_push_back(&data, (unsigned char)textstring[i]);
  }
  
  if(!error) error = addChunk(out, "iTXt", data.data, data.size);
  ucvector_cleanup(&data);
  return error;
}

static unsigned addChunk_bKGD(ucvector* out, const LodePNG_InfoPng* info)
{
  unsigned error = 0;
  ucvector bKGD;
  ucvector_init(&bKGD);
  if(info->color.colorType == 0 || info->color.colorType == 4)
  {
    ucvector_push_back(&bKGD, (unsigned char)(info->background_r / 256));
    ucvector_push_back(&bKGD, (unsigned char)(info->background_r % 256));
  }
  else if(info->color.colorType == 2 || info->color.colorType == 6)
  {
    ucvector_push_back(&bKGD, (unsigned char)(info->background_r / 256));
    ucvector_push_back(&bKGD, (unsigned char)(info->background_r % 256));
    ucvector_push_back(&bKGD, (unsigned char)(info->background_g / 256));
    ucvector_push_back(&bKGD, (unsigned char)(info->background_g % 256));
    ucvector_push_back(&bKGD, (unsigned char)(info->background_b / 256));
    ucvector_push_back(&bKGD, (unsigned char)(info->background_b % 256));
  }
  else if(info->color.colorType == 3)
  {
    ucvector_push_back(&bKGD, (unsigned char)(info->background_r % 256)); /*palette index*/
  }
  
  error = addChunk(out, "bKGD", bKGD.data, bKGD.size);
  ucvector_cleanup(&bKGD);
  
  return error;
}

static unsigned addChunk_tIME(ucvector* out, const LodePNG_Time* time)
{
  unsigned error = 0;
  unsigned char* data = (unsigned char*)malloc(7);
  if(!data) return 9948;
  data[0] = (unsigned char)(time->year / 256);
  data[1] = (unsigned char)(time->year % 256);
  data[2] = time->month;
  data[3] = time->day;
  data[4] = time->hour;
  data[5] = time->minute;
  data[6] = time->second;
  error = addChunk(out, "tIME", data, 7);
  free(data);
  return error;
}

static unsigned addChunk_pHYs(ucvector* out, const LodePNG_InfoPng* info)
{
  unsigned error = 0;
  ucvector data;
  ucvector_init(&data);
  
  LodePNG_add32bitInt(&data, info->phys_x);
  LodePNG_add32bitInt(&data, info->phys_y);
  ucvector_push_back(&data, info->phys_unit);
  
  error = addChunk(out, "pHYs", data.data, data.size);
  ucvector_cleanup(&data);
  
  return error;
}

#endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/

static void filterScanline(unsigned char* out, const unsigned char* scanline, const unsigned char* prevline, size_t length, size_t bytewidth, unsigned char filterType)
{
  size_t i;
  switch(filterType)
  {
    case 0:
      for(i = 0; i < length; i++) out[i] = scanline[i];
      break;
    case 1:
      for(i =         0; i < bytewidth; i++) out[i] = scanline[i];
      for(i = bytewidth; i <    length; i++) out[i] = scanline[i] - scanline[i - bytewidth];
      break;
    case 2:
      if(prevline) for(i = 0; i < length; i++) out[i] = scanline[i] - prevline[i];
      else         for(i = 0; i < length; i++) out[i] = scanline[i];
      break;
    case 3:
      if(prevline)
      {
        for(i =         0; i < bytewidth; i++) out[i] = scanline[i] - prevline[i] / 2;
        for(i = bytewidth; i <    length; i++) out[i] = scanline[i] - ((scanline[i - bytewidth] + prevline[i]) / 2);
      }
      else
      {
        for(i =         0; i < length; i++) out[i] = scanline[i];
        for(i = bytewidth; i < length; i++) out[i] = scanline[i] - scanline[i - bytewidth] / 2;
      }
      break;
    case 4:
      if(prevline)
      {
        for(i =         0; i < bytewidth; i++) out[i] = (unsigned char)(scanline[i] - paethPredictor(0, prevline[i], 0));
        for(i = bytewidth; i <    length; i++) out[i] = (unsigned char)(scanline[i] - paethPredictor(scanline[i - bytewidth], prevline[i], prevline[i - bytewidth]));
      }
      else
      {
        for(i =         0; i < bytewidth; i++) out[i] = scanline[i];
        for(i = bytewidth; i <    length; i++) out[i] = (unsigned char)(scanline[i] - paethPredictor(scanline[i - bytewidth], 0, 0));
      }
      break;
  default: return; /*unexisting filter type given*/
  }
}

static unsigned filter(unsigned char* out, const unsigned char* in, unsigned w, unsigned h, const LodePNG_InfoColor* info)
{
  /*
  For PNG filter method 0
  out must be a buffer with as size: h + (w * h * bpp + 7) / 8, because there are the scanlines with 1 extra byte per scanline
  
  There is a nice heuristic described here: http://www.cs.toronto.edu/~cosmin/pngtech/optipng.html. It says:
   *  If the image type is Palette, or the bit depth is smaller than 8, then do not filter the image (i.e. use fixed filtering, with the filter None).
   * (The other case) If the image type is Grayscale or RGB (with or without Alpha), and the bit depth is not smaller than 8, then use adaptive filtering heuristic as follows: independently for each row, apply all five filters and select the filter that produces the smallest sum of absolute values per row.
  
  Here the above method is used mostly. Note though that it appears to be better to use the adaptive filtering on the plasma 8-bit palette example, but that image isn't the best reference for palette images in general.
  */
  
  unsigned bpp = LodePNG_InfoColor_getBpp(info);
  size_t linebytes = (w * bpp + 7) / 8; /*the width of a scanline in bytes, not including the filter type*/
  size_t bytewidth = (bpp + 7) / 8; /*bytewidth is used for filtering, is 1 when bpp < 8, number of bytes per pixel otherwise*/
  const unsigned char* prevline = 0;
  unsigned x, y;
  unsigned heuristic;
  unsigned error = 0;
  
  if(bpp == 0) return 31; /*invalid color type*/
  
  /*choose heuristic as described above*/
  if(info->colorType == 3 || info->bitDepth < 8) heuristic = 0;
  else heuristic = 1;
  
  if(heuristic == 0) /*None filtertype for everything*/
  {
    for(y = 0; y < h; y++)
    {
      size_t outindex = (1 + linebytes) * y; /*the extra filterbyte added to each row*/
      size_t inindex = linebytes * y;
      const unsigned TYPE = 0;
      out[outindex] = TYPE; /*filter type byte*/
      filterScanline(&out[outindex + 1], &in[inindex], prevline, linebytes, bytewidth, TYPE);
      prevline = &in[inindex];
    }
  }
  else if(heuristic == 1) /*adaptive filtering*/
  {
    size_t sum[5];
    ucvector attempt[5]; /*five filtering attempts, one for each filter type*/
    size_t smallest = 0;
    unsigned type, bestType = 0;
    
    for(type = 0; type < 5; type++) ucvector_init(&attempt[type]);
    for(type = 0; type < 5; type++)
    {
      if(!ucvector_resize(&attempt[type], linebytes)) { error = 9949; break; }
    }
    
    if(!error)
    {
      for(y = 0; y < h; y++)
      {
        /*try the 5 filter types*/
        for(type = 0; type < 5; type++)
        {
          filterScanline(attempt[type].data, &in[y * linebytes], prevline, linebytes, bytewidth, type);
          
          /*calculate the sum of the result*/
          sum[type] = 0;
          for(x = 0; x < attempt[type].size; x+=3) sum[type] += attempt[type].data[x]; /*note that not all pixels are checked to speed this up while still having probably the best choice*/
        
          /*check if this is smallest sum (or if type == 0 it's the first case so always store the values)*/
          if(type == 0 || sum[type] < smallest)
          {
            bestType = type;
            smallest = sum[type];
          }
        }
        
        prevline = &in[y * linebytes];
    
        /*now fill the out values*/
        out[y * (linebytes + 1)] = bestType; /*the first byte of a scanline will be the filter type*/
        for(x = 0; x < linebytes; x++) out[y * (linebytes + 1) + 1 + x] = attempt[bestType].data[x];
      }
    }
    
    for(type = 0; type < 5; type++) ucvector_cleanup(&attempt[type]);
  }
  #if 0 /*deflate the scanline with a fixed tree after every filter attempt to see which one deflates best. This is slow, and _does not work as expected_: the heuristic gives smaller result!*/
  else if(heuristic == 2) /*adaptive filtering by using deflate*/
  {
    size_t size[5];
    ucvector attempt[5]; /*five filtering attempts, one for each filter type*/
    size_t smallest;
    unsigned type = 0, bestType = 0;
    unsigned char* dummy;
    LodeZlib_DeflateSettings deflatesettings = LodeZlib_defaultDeflateSettings;
    deflatesettings.btype = 1; /*use fixed tree on the attempts so that the tree is not adapted to the filtertype on purpose, to simulate the true case where the tree is the same for the whole image*/
    for(type = 0; type < 5; type++) { ucvector_init(&attempt[type]); ucvector_resize(&attempt[type], linebytes); }
    for(y = 0; y < h; y++) /*try the 5 filter types*/
    {
      for(type = 0; type < 5; type++)
      {
        filterScanline(attempt[type].data, &in[y * linebytes], prevline, linebytes, bytewidth, type);
        size[type] = 0; dummy = 0;
        LodePNG_compress(&dummy, &size[type], attempt[type].data, attempt[type].size, &deflatesettings);
        free(dummy);
        /*check if this is smallest size (or if type == 0 it's the first case so always store the values)*/
        if(type == 0 || size[type] < smallest) { bestType = type; smallest = size[type]; }
      }
      prevline = &in[y * linebytes];
      out[y * (linebytes + 1)] = bestType; /*the first byte of a scanline will be the filter type*/
      for(x = 0; x < linebytes; x++) out[y * (linebytes + 1) + 1 + x] = attempt[bestType].data[x];
    }
    for(type = 0; type < 5; type++) ucvector_cleanup(&attempt[type]);
  }
  #endif
  
  return error;
}

static void addPaddingBits(unsigned char* out, const unsigned char* in, size_t olinebits, size_t ilinebits, unsigned h)
{
  /*The opposite of the removePaddingBits function
  olinebits must be >= ilinebits*/
  unsigned y;
  size_t diff = olinebits - ilinebits;
  size_t obp = 0, ibp = 0; /*bit pointers*/
  for(y = 0; y < h; y++)
  {
    size_t x;
    for(x = 0; x < ilinebits; x++)
    {
      unsigned char bit = readBitFromReversedStream(&ibp, in);
      setBitOfReversedStream(&obp, out, bit);
    }
    /*obp += diff; --> no, fill in some value in the padding bits too, to avoid "Use of uninitialised value of size ###" warning from valgrind*/
    for(x = 0; x < diff; x++) setBitOfReversedStream(&obp, out, 0);
  }
}

static void Adam7_interlace(unsigned char* out, const unsigned char* in, unsigned w, unsigned h, unsigned bpp)
{
  /*Note: this function works on image buffers WITHOUT padding bits at end of scanlines with non-multiple-of-8 bit amounts, only between reduced images is padding*/
  unsigned passw[7], passh[7]; size_t filter_passstart[8], padded_passstart[8], passstart[8];
  unsigned i;

  Adam7_getpassvalues(passw, passh, filter_passstart, padded_passstart, passstart, w, h, bpp);
  
  if(bpp >= 8)
  {
    for(i = 0; i < 7; i++)
    {
      unsigned x, y, b;
      size_t bytewidth = bpp / 8;
      for(y = 0; y < passh[i]; y++)
      for(x = 0; x < passw[i]; x++)
      {
        size_t pixelinstart = ((ADAM7_IY[i] + y * ADAM7_DY[i]) * w + ADAM7_IX[i] + x * ADAM7_DX[i]) * bytewidth;
        size_t pixeloutstart = passstart[i] + (y * passw[i] + x) * bytewidth;
        for(b = 0; b < bytewidth; b++)
        {
          out[pixeloutstart + b] = in[pixelinstart + b];
        }
      }
    }
  }
  else /*bpp < 8: Adam7 with pixels < 8 bit is a bit trickier: with bit pointers*/
  {
    for(i = 0; i < 7; i++)
    {
      unsigned x, y, b;
      unsigned ilinebits = bpp * passw[i];
      unsigned olinebits = bpp * w;
      size_t obp, ibp; /*bit pointers (for out and in buffer)*/
      for(y = 0; y < passh[i]; y++)
      for(x = 0; x < passw[i]; x++)
      {
        ibp = (ADAM7_IY[i] + y * ADAM7_DY[i]) * olinebits + (ADAM7_IX[i] + x * ADAM7_DX[i]) * bpp;
        obp = (8 * passstart[i]) + (y * ilinebits + x * bpp);
        for(b = 0; b < bpp; b++)
        {
          unsigned char bit = readBitFromReversedStream(&ibp, in);
          setBitOfReversedStream(&obp, out, bit);
        }
      }
    }
  }
}

/*out must be buffer big enough to contain uncompressed IDAT chunk data, and in must contain the full image*/
static unsigned preProcessScanlines(unsigned char** out, size_t* outsize, const unsigned char* in, const LodePNG_InfoPng* infoPng) /*return value is error*/
{
  /*
  This function converts the pure 2D image with the PNG's colortype, into filtered-padded-interlaced data. Steps:
  *) if no Adam7: 1) add padding bits (= posible extra bits per scanline if bpp < 8) 2) filter
  *) if adam7: 1) Adam7_interlace 2) 7x add padding bits 3) 7x filter
  */
  unsigned bpp = LodePNG_InfoColor_getBpp(&infoPng->color);
  unsigned w = infoPng->width;
  unsigned h = infoPng->height;
  unsigned error = 0;
  
  if(infoPng->interlaceMethod == 0)
  {
    *outsize = h + (h * ((w * bpp + 7) / 8)); /*image size plus an extra byte per scanline + possible padding bits*/
    *out = (unsigned char*)malloc(*outsize);
    if(!(*out) && (*outsize)) error = 9950;

    if(!error)
    {
      if(bpp < 8 && w * bpp != ((w * bpp + 7) / 8) * 8) /*non multiple of 8 bits per scanline, padding bits needed per scanline*/
      {
        ucvector padded;
        ucvector_init(&padded);
        if(!ucvector_resize(&padded, h * ((w * bpp + 7) / 8))) error = 9951;
        if(!error)
        {
          addPaddingBits(padded.data, in, ((w * bpp + 7) / 8) * 8, w * bpp, h);
          error = filter(*out, padded.data, w, h, &infoPng->color);
        }
        ucvector_cleanup(&padded);
      }
      else error = filter(*out, in, w, h, &infoPng->color); /*we can immediatly filter into the out buffer, no other steps needed*/
    }
  }
  else /*interlaceMethod is 1 (Adam7)*/
  {
    unsigned char* adam7 = (unsigned char*)malloc((h * w * bpp + 7) / 8);
    if(!adam7 && ((h * w * bpp + 7) / 8)) error = 9952; /*malloc failed*/
    
    while(!error) /*not a real while loop, used to break out to cleanup to avoid a goto*/
    {
      unsigned passw[7], passh[7]; size_t filter_passstart[8], padded_passstart[8], passstart[8];
      unsigned i;
      
      Adam7_getpassvalues(passw, passh, filter_passstart, padded_passstart, passstart, w, h, bpp);
      
      *outsize = filter_passstart[7]; /*image size plus an extra byte per scanline + possible padding bits*/
      *out = (unsigned char*)malloc(*outsize);
      if(!(*out) && (*outsize)) { error = 9953; break; }
      
      Adam7_interlace(adam7, in, w, h, bpp);
      
      for(i = 0; i < 7; i++)
      {
        if(bpp < 8)
        {
          ucvector padded;
          ucvector_init(&padded);
          if(!ucvector_resize(&padded, h * ((w * bpp + 7) / 8))) error = 9954;
          if(!error)
          {
            addPaddingBits(&padded.data[padded_passstart[i]], &adam7[passstart[i]], ((passw[i] * bpp + 7) / 8) * 8, passw[i] * bpp, passh[i]);
            error = filter(&(*out)[filter_passstart[i]], &padded.data[padded_passstart[i]], passw[i], passh[i], &infoPng->color);
          }
          
          ucvector_cleanup(&padded);
        }
        else
        {
          error = filter(&(*out)[filter_passstart[i]], &adam7[padded_passstart[i]], passw[i], passh[i], &infoPng->color);
        }
      }
      
      break;
    }

    free(adam7);
  }
  
  return error;
}

/*palette must have 4 * palettesize bytes allocated*/
static unsigned isPaletteFullyOpaque(const unsigned char* palette, size_t palettesize) /*palette given in format RGBARGBARGBARGBA...*/
{
  size_t i;
  for(i = 0; i < palettesize; i++)
  {
    if(palette[4 * i + 3] != 255) return 0;
  }
  return 1;
}

/*this function checks if the input image given by the user has no transparent pixels*/
static unsigned isFullyOpaque(const unsigned char* image, unsigned w, unsigned h, const LodePNG_InfoColor* info)
{
  /*TODO: When the user specified a color key for the input image, then this function must also check for pixels that are the same as the color key and treat those as transparent.*/

  unsigned i, numpixels = w * h;
  if(info->colorType == 6)
  {
    if(info->bitDepth == 8)
    {
      for(i = 0; i < numpixels; i++) if(image[i * 4 + 3] != 255) return 0;
    }
    else
    {
      for(i = 0; i < numpixels; i++) if(image[i * 8 + 6] != 255 || image[i * 8 + 7] != 255) return 0;
    }
    return 1; /*no single pixel with alpha channel other than 255 found*/
  }
  else if(info->colorType == 4)
  {
    if(info->bitDepth == 8)
    {
      for(i = 0; i < numpixels; i++) if(image[i * 2 + 1] != 255) return 0;
    }
    else
    {
      for(i = 0; i < numpixels; i++) if(image[i * 4 + 2] != 255 || image[i * 4 + 3] != 255) return 0;
    }
    return 1; /*no single pixel with alpha channel other than 255 found*/
  }
  else if(info->colorType == 3)
  {
    /*when there's a palette, we could check every pixel for translucency, but much quicker is to just check the palette*/
    return(isPaletteFullyOpaque(info->palette, info->palettesize));
  }

  return 0; /*color type that isn't supported by this function yet, so assume there is transparency to be safe*/
}

#ifdef LODEPNG_COMPILE_UNKNOWN_CHUNKS
static unsigned addUnknownChunks(ucvector* out, unsigned char* data, size_t datasize)
{
  unsigned char* inchunk = data;
  while((size_t)(inchunk - data) < datasize)
  {
    unsigned error = LodePNG_append_chunk(&out->data, &out->size, inchunk);
    if(error) return error; /*error: not enough memory*/
    out->allocsize = out->size; /*fix the allocsize again*/
    inchunk = LodePNG_chunk_next(inchunk);
  }
  return 0;
}
#endif /*LODEPNG_COMPILE_UNKNOWN_CHUNKS*/

void LodePNG_encode(LodePNG_Encoder* encoder, unsigned char** out, size_t* outsize, const unsigned char* image, unsigned w, unsigned h)
{
  LodePNG_InfoPng info;
  ucvector outv;
  unsigned char* data = 0; /*uncompressed version of the IDAT chunk data*/
  size_t datasize = 0;
  
  /*provide some proper output values if error will happen*/
  *out = 0;
  *outsize = 0;
  encoder->error = 0;
  
  info = encoder->infoPng; /*UNSAFE copy to avoid having to cleanup! but we will only change primitive parameters, and not invoke the cleanup function nor touch the palette's buffer so we use it safely*/
  info.width = w;
  info.height = h;
  
  if(encoder->settings.autoLeaveOutAlphaChannel && isFullyOpaque(image, w, h, &encoder->infoRaw.color))
  {
    /*go to a color type without alpha channel*/
    if(info.color.colorType == 6) info.color.colorType = 2;
    else if(info.color.colorType == 4) info.color.colorType = 0;
  }
  
  if(encoder->settings.zlibsettings.windowSize > 32768) { encoder->error = 60; return; } /*error: windowsize larger than allowed*/
  if(encoder->settings.zlibsettings.btype > 2) { encoder->error = 61; return; } /*error: unexisting btype*/
  if(encoder->infoPng.interlaceMethod > 1) { encoder->error = 71; return; } /*error: unexisting interlace mode*/
  if((encoder->error = checkColorValidity(info.color.colorType, info.color.bitDepth))) return; /*error: unexisting color type given*/
  if((encoder->error = checkColorValidity(encoder->infoRaw.color.colorType, encoder->infoRaw.color.bitDepth))) return; /*error: unexisting color type given*/
  
  if(!LodePNG_InfoColor_equal(&encoder->infoRaw.color, &info.color))
  {
    unsigned char* converted;
    size_t size = (w * h * LodePNG_InfoColor_getBpp(&info.color) + 7) / 8;
    
    if((info.color.colorType != 6 && info.color.colorType != 2) || (info.color.bitDepth != 8)) { encoder->error = 59; return; } /*for the output image, only these types are supported*/
    converted = (unsigned char*)malloc(size);
    if(!converted && size) encoder->error = 9955; /*error: malloc failed*/
    if(!encoder->error) encoder->error = LodePNG_convert(converted, image, &info.color, &encoder->infoRaw.color, w, h);
    if(!encoder->error) preProcessScanlines(&data, &datasize, converted, &info);/*filter(data.data, converted.data, w, h, LodePNG_InfoColor_getBpp(&info.color));*/
    free(converted);
  }
  else preProcessScanlines(&data, &datasize, image, &info);/*filter(data.data, image, w, h, LodePNG_InfoColor_getBpp(&info.color));*/
  
  ucvector_init(&outv);
  while(!encoder->error) /*not really a while loop, this is only used to break out if an error happens to avoid goto's to do the ucvector cleanup*/
  {
#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS
    size_t i;
#endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/
    /*write signature and chunks*/
    writeSignature(&outv);
    /*IHDR*/
    addChunk_IHDR(&outv, w, h, info.color.bitDepth, info.color.colorType, info.interlaceMethod);
#ifdef LODEPNG_COMPILE_UNKNOWN_CHUNKS
    /*unknown chunks between IHDR and PLTE*/
    if(info.unknown_chunks.data[0]) { encoder->error = addUnknownChunks(&outv, info.unknown_chunks.data[0], info.unknown_chunks.datasize[0]); if(encoder->error) break; }
#endif /*LODEPNG_COMPILE_UNKNOWN_CHUNKS*/
    /*PLTE*/
    if(info.color.colorType == 3)
    {
      if(info.color.palettesize == 0 || info.color.palettesize > 256) { encoder->error = 68; break; }
      addChunk_PLTE(&outv, &info.color);
    }
    if(encoder->settings.force_palette && (info.color.colorType == 2 || info.color.colorType == 6))
    {
      if(info.color.palettesize == 0 || info.color.palettesize > 256) { encoder->error = 68; break; }
      addChunk_PLTE(&outv, &info.color);
    }
    /*tRNS*/
    if(info.color.colorType == 3 && !isPaletteFullyOpaque(info.color.palette, info.color.palettesize)) addChunk_tRNS(&outv, &info.color);
    if((info.color.colorType == 0 || info.color.colorType == 2) && info.color.key_defined) addChunk_tRNS(&outv, &info.color);
#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS
    /*bKGD (must come between PLTE and the IDAt chunks*/
    if(info.background_defined) addChunk_bKGD(&outv, &info);
    /*pHYs (must come before the IDAT chunks)*/
    if(info.phys_defined) addChunk_pHYs(&outv, &info);
#endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/
#ifdef LODEPNG_COMPILE_UNKNOWN_CHUNKS
    /*unknown chunks between PLTE and IDAT*/
    if(info.unknown_chunks.data[1]) { encoder->error = addUnknownChunks(&outv, info.unknown_chunks.data[1], info.unknown_chunks.datasize[1]); if(encoder->error) break; }
#endif /*LODEPNG_COMPILE_UNKNOWN_CHUNKS*/
    /*IDAT (multiple IDAT chunks must be consecutive)*/
    encoder->error = addChunk_IDAT(&outv, data, datasize, &encoder->settings.zlibsettings);
    if(encoder->error) break;
#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS
    /*tIME*/
    if(info.time_defined) addChunk_tIME(&outv, &info.time);
    /*tEXt and/or zTXt*/
    for(i = 0; i < info.text.num; i++)
    {
      if(strlen(info.text.keys[i]) > 79) { encoder->error = 66; break; }
      if(strlen(info.text.keys[i]) < 1) { encoder->error = 67; break; }
      if(encoder->settings.text_compression)
        addChunk_zTXt(&outv, info.text.keys[i], info.text.strings[i], &encoder->settings.zlibsettings);
      else
        addChunk_tEXt(&outv, info.text.keys[i], info.text.strings[i]);
    }
    /*LodePNG version id in text chunk*/
    if(encoder->settings.add_id)
    {
      unsigned alread_added_id_text = 0;
      for(i = 0; i < info.text.num; i++)
        if(!strcmp(info.text.keys[i], "LodePNG")) { alread_added_id_text = 1; break; }
      if(alread_added_id_text == 0)
        addChunk_tEXt(&outv, "LodePNG", VERSION_STRING); /*it's shorter as tEXt than as zTXt chunk*/
    }
    /*iTXt*/
    for(i = 0; i < info.itext.num; i++)
    {
      if(strlen(info.itext.keys[i]) > 79) { encoder->error = 66; break; }
      if(strlen(info.itext.keys[i]) < 1) { encoder->error = 67; break; }
      addChunk_iTXt(&outv, encoder->settings.text_compression,
                    info.itext.keys[i], info.itext.langtags[i], info.itext.transkeys[i], info.itext.strings[i], 
                    &encoder->settings.zlibsettings);
    }
#endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/
#ifdef LODEPNG_COMPILE_UNKNOWN_CHUNKS
    /*unknown chunks between IDAT and IEND*/
    if(info.unknown_chunks.data[2]) { encoder->error = addUnknownChunks(&outv, info.unknown_chunks.data[2], info.unknown_chunks.datasize[2]); if(encoder->error) break; }
#endif /*LODEPNG_COMPILE_UNKNOWN_CHUNKS*/
    /*IEND*/
    addChunk_IEND(&outv);
    
    break; /*this isn't really a while loop; no error happened so break out now!*/
  }
  
  free(data);
  /*instead of cleaning the vector up, give it to the output*/
  *out = outv.data;
  *outsize = outv.size;
}

unsigned LodePNG_encode32(unsigned char** out, size_t* outsize, const unsigned char* image, unsigned w, unsigned h)
{
  unsigned error;
  LodePNG_Encoder encoder;
  LodePNG_Encoder_init(&encoder);
  LodePNG_encode(&encoder, out, outsize, image, w, h);
  error = encoder.error;
  LodePNG_Encoder_cleanup(&encoder);
  return error;
}

#ifdef LODEPNG_COMPILE_DISK
unsigned LodePNG_encode32f(const char* filename, const unsigned char* image, unsigned w, unsigned h)
{
  unsigned char* buffer;
  size_t buffersize;
  unsigned error = LodePNG_encode32(&buffer, &buffersize, image, w, h);
  LodePNG_saveFile(buffer, buffersize, filename);
  free(buffer);
  return error;
}
#endif /*LODEPNG_COMPILE_DISK*/

void LodePNG_EncodeSettings_init(LodePNG_EncodeSettings* settings)
{
  LodeZlib_DeflateSettings_init(&settings->zlibsettings);
  settings->autoLeaveOutAlphaChannel = 1;
  settings->force_palette = 0;
#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS
  settings->add_id = 1;
  settings->text_compression = 0;
#endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/
}

void LodePNG_Encoder_init(LodePNG_Encoder* encoder)
{
  LodePNG_EncodeSettings_init(&encoder->settings);
  LodePNG_InfoPng_init(&encoder->infoPng);
  LodePNG_InfoRaw_init(&encoder->infoRaw);
  encoder->error = 1;
}

void LodePNG_Encoder_cleanup(LodePNG_Encoder* encoder)
{
  LodePNG_InfoPng_cleanup(&encoder->infoPng);
  LodePNG_InfoRaw_cleanup(&encoder->infoRaw);
}

void LodePNG_Encoder_copy(LodePNG_Encoder* dest, const LodePNG_Encoder* source)
{
  LodePNG_Encoder_cleanup(dest);
  *dest = *source;
  LodePNG_InfoPng_init(&dest->infoPng);
  LodePNG_InfoRaw_init(&dest->infoRaw);
  dest->error = LodePNG_InfoPng_copy(&dest->infoPng, &source->infoPng); if(dest->error) return;
  dest->error = LodePNG_InfoRaw_copy(&dest->infoRaw, &source->infoRaw); if(dest->error) return;
}

#endif /*LODEPNG_COMPILE_ENCODER*/

#endif /*LODEPNG_COMPILE_PNG*/

/* ////////////////////////////////////////////////////////////////////////// */
/* / File IO                                                                / */
/* ////////////////////////////////////////////////////////////////////////// */

#ifdef LODEPNG_COMPILE_DISK

unsigned LodePNG_loadFile(unsigned char** out, size_t* outsize, const char* filename) /*designed for loading files from hard disk in a dynamically allocated buffer*/
{
  FILE* file;
  long size;
  
  /*provide some proper output values if error will happen*/
  *out = 0;
  *outsize = 0;

  file = portable_fopen(filename, "rb");
  if(!file) return 78;

  /*get filesize:*/
  fseek(file , 0 , SEEK_END);
  size = ftell(file);
  rewind(file);
  
  /*read contents of the file into the vector*/
  if (size>0)
  {
    *outsize = 0;
    *out = (unsigned char*)malloc((size_t)size);
    if(size && (*out)) (*outsize) = fread(*out, 1, (size_t)size, file);
  }

  fclose(file);
  if(!(*out) && size) return 80; /*the above malloc failed*/
  return 0;
}

/*write given buffer to the file, overwriting the file, it doesn't append to it.*/
unsigned LodePNG_saveFile(const unsigned char* buffer, size_t buffersize, const char* filename)
{
  FILE* file;
  file = portable_fopen(filename, "wb" );
  if(!file) return 79;
  fwrite((char*)buffer , 1 , buffersize, file);
  fclose(file);
  return 0;
}

#endif /*LODEPNG_COMPILE_DISK*/