summaryrefslogtreecommitdiffstats
path: root/src/mesa/main/glformats.c
blob: 9bb341cc0e95997e3455631a999755fc609b02c3 (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
/*
 * Mesa 3-D graphics library
 *
 * Copyright (C) 1999-2008  Brian Paul   All Rights Reserved.
 * Copyright (c) 2008-2009  VMware, Inc.
 * Copyright (c) 2012 Intel Corporation
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the "Software"),
 * to deal in the Software without restriction, including without limitation
 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
 * and/or sell copies of the Software, and to permit persons to whom the
 * Software is furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included
 * in all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
 * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
 * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
 * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
 * OTHER DEALINGS IN THE SOFTWARE.
 */


#include "context.h"
#include "glformats.h"


/**
 * \return GL_TRUE if type is packed pixel type, GL_FALSE otherwise.
 */
GLboolean
_mesa_type_is_packed(GLenum type)
{
   switch (type) {
   case GL_UNSIGNED_BYTE_3_3_2:
   case GL_UNSIGNED_BYTE_2_3_3_REV:
   case MESA_UNSIGNED_BYTE_4_4:
   case GL_UNSIGNED_SHORT_5_6_5:
   case GL_UNSIGNED_SHORT_5_6_5_REV:
   case GL_UNSIGNED_SHORT_4_4_4_4:
   case GL_UNSIGNED_SHORT_4_4_4_4_REV:
   case GL_UNSIGNED_SHORT_5_5_5_1:
   case GL_UNSIGNED_SHORT_1_5_5_5_REV:
   case GL_UNSIGNED_INT_8_8_8_8:
   case GL_UNSIGNED_INT_8_8_8_8_REV:
   case GL_UNSIGNED_INT_10_10_10_2:
   case GL_UNSIGNED_INT_2_10_10_10_REV:
   case GL_UNSIGNED_SHORT_8_8_MESA:
   case GL_UNSIGNED_SHORT_8_8_REV_MESA:
   case GL_UNSIGNED_INT_24_8_EXT:
   case GL_UNSIGNED_INT_5_9_9_9_REV:
   case GL_UNSIGNED_INT_10F_11F_11F_REV:
   case GL_FLOAT_32_UNSIGNED_INT_24_8_REV:
      return GL_TRUE;
   }

   return GL_FALSE;
}


/**
 * Get the size of a GL data type.
 *
 * \param type GL data type.
 *
 * \return the size, in bytes, of the given data type, 0 if a GL_BITMAP, or -1
 * if an invalid type enum.
 */
GLint
_mesa_sizeof_type(GLenum type)
{
   switch (type) {
   case GL_BITMAP:
      return 0;
   case GL_UNSIGNED_BYTE:
      return sizeof(GLubyte);
   case GL_BYTE:
      return sizeof(GLbyte);
   case GL_UNSIGNED_SHORT:
      return sizeof(GLushort);
   case GL_SHORT:
      return sizeof(GLshort);
   case GL_UNSIGNED_INT:
      return sizeof(GLuint);
   case GL_INT:
      return sizeof(GLint);
   case GL_FLOAT:
      return sizeof(GLfloat);
   case GL_DOUBLE:
      return sizeof(GLdouble);
   case GL_HALF_FLOAT_ARB:
      return sizeof(GLhalfARB);
   case GL_FIXED:
      return sizeof(GLfixed);
   default:
      return -1;
   }
}


/**
 * Same as _mesa_sizeof_type() but also accepting the packed pixel
 * format data types.
 */
GLint
_mesa_sizeof_packed_type(GLenum type)
{
   switch (type) {
   case GL_BITMAP:
      return 0;
   case GL_UNSIGNED_BYTE:
      return sizeof(GLubyte);
   case GL_BYTE:
      return sizeof(GLbyte);
   case GL_UNSIGNED_SHORT:
      return sizeof(GLushort);
   case GL_SHORT:
      return sizeof(GLshort);
   case GL_UNSIGNED_INT:
      return sizeof(GLuint);
   case GL_INT:
      return sizeof(GLint);
   case GL_HALF_FLOAT_ARB:
      return sizeof(GLhalfARB);
   case GL_FLOAT:
      return sizeof(GLfloat);
   case GL_UNSIGNED_BYTE_3_3_2:
   case GL_UNSIGNED_BYTE_2_3_3_REV:
   case MESA_UNSIGNED_BYTE_4_4:
      return sizeof(GLubyte);
   case GL_UNSIGNED_SHORT_5_6_5:
   case GL_UNSIGNED_SHORT_5_6_5_REV:
   case GL_UNSIGNED_SHORT_4_4_4_4:
   case GL_UNSIGNED_SHORT_4_4_4_4_REV:
   case GL_UNSIGNED_SHORT_5_5_5_1:
   case GL_UNSIGNED_SHORT_1_5_5_5_REV:
   case GL_UNSIGNED_SHORT_8_8_MESA:
   case GL_UNSIGNED_SHORT_8_8_REV_MESA:
      return sizeof(GLushort);
   case GL_UNSIGNED_INT_8_8_8_8:
   case GL_UNSIGNED_INT_8_8_8_8_REV:
   case GL_UNSIGNED_INT_10_10_10_2:
   case GL_UNSIGNED_INT_2_10_10_10_REV:
   case GL_UNSIGNED_INT_24_8_EXT:
   case GL_UNSIGNED_INT_5_9_9_9_REV:
   case GL_UNSIGNED_INT_10F_11F_11F_REV:
      return sizeof(GLuint);
   case GL_FLOAT_32_UNSIGNED_INT_24_8_REV:
      return 8;
   default:
      return -1;
   }
}


/**
 * Get the number of components in a pixel format.
 *
 * \param format pixel format.
 *
 * \return the number of components in the given format, or -1 if a bad format.
 */
GLint
_mesa_components_in_format(GLenum format)
{
   switch (format) {
   case GL_COLOR_INDEX:
   case GL_STENCIL_INDEX:
   case GL_DEPTH_COMPONENT:
   case GL_RED:
   case GL_RED_INTEGER_EXT:
   case GL_GREEN:
   case GL_GREEN_INTEGER_EXT:
   case GL_BLUE:
   case GL_BLUE_INTEGER_EXT:
   case GL_ALPHA:
   case GL_ALPHA_INTEGER_EXT:
   case GL_LUMINANCE:
   case GL_LUMINANCE_INTEGER_EXT:
   case GL_INTENSITY:
      return 1;

   case GL_LUMINANCE_ALPHA:
   case GL_LUMINANCE_ALPHA_INTEGER_EXT:
   case GL_RG:
   case GL_YCBCR_MESA:
   case GL_DEPTH_STENCIL_EXT:
   case GL_DUDV_ATI:
   case GL_DU8DV8_ATI:
   case GL_RG_INTEGER:
      return 2;

   case GL_RGB:
   case GL_BGR:
   case GL_RGB_INTEGER_EXT:
   case GL_BGR_INTEGER_EXT:
      return 3;

   case GL_RGBA:
   case GL_BGRA:
   case GL_ABGR_EXT:
   case GL_RGBA_INTEGER_EXT:
   case GL_BGRA_INTEGER_EXT:
      return 4;

   default:
      return -1;
   }
}


/**
 * Get the bytes per pixel of pixel format type pair.
 *
 * \param format pixel format.
 * \param type pixel type.
 *
 * \return bytes per pixel, or -1 if a bad format or type was given.
 */
GLint
_mesa_bytes_per_pixel(GLenum format, GLenum type)
{
   GLint comps = _mesa_components_in_format(format);
   if (comps < 0)
      return -1;

   switch (type) {
   case GL_BITMAP:
      return 0;  /* special case */
   case GL_BYTE:
   case GL_UNSIGNED_BYTE:
      return comps * sizeof(GLubyte);
   case GL_SHORT:
   case GL_UNSIGNED_SHORT:
      return comps * sizeof(GLshort);
   case GL_INT:
   case GL_UNSIGNED_INT:
      return comps * sizeof(GLint);
   case GL_FLOAT:
      return comps * sizeof(GLfloat);
   case GL_HALF_FLOAT_ARB:
      return comps * sizeof(GLhalfARB);
   case GL_UNSIGNED_BYTE_3_3_2:
   case GL_UNSIGNED_BYTE_2_3_3_REV:
      if (format == GL_RGB || format == GL_BGR ||
          format == GL_RGB_INTEGER_EXT || format == GL_BGR_INTEGER_EXT)
         return sizeof(GLubyte);
      else
         return -1;  /* error */
   case GL_UNSIGNED_SHORT_5_6_5:
   case GL_UNSIGNED_SHORT_5_6_5_REV:
      if (format == GL_RGB || format == GL_BGR ||
          format == GL_RGB_INTEGER_EXT || format == GL_BGR_INTEGER_EXT)
         return sizeof(GLushort);
      else
         return -1;  /* error */
   case GL_UNSIGNED_SHORT_4_4_4_4:
   case GL_UNSIGNED_SHORT_4_4_4_4_REV:
   case GL_UNSIGNED_SHORT_5_5_5_1:
   case GL_UNSIGNED_SHORT_1_5_5_5_REV:
      if (format == GL_RGBA || format == GL_BGRA || format == GL_ABGR_EXT ||
          format == GL_RGBA_INTEGER_EXT || format == GL_BGRA_INTEGER_EXT)
         return sizeof(GLushort);
      else
         return -1;
   case GL_UNSIGNED_INT_8_8_8_8:
   case GL_UNSIGNED_INT_8_8_8_8_REV:
   case GL_UNSIGNED_INT_10_10_10_2:
   case GL_UNSIGNED_INT_2_10_10_10_REV:
      if (format == GL_RGBA || format == GL_BGRA || format == GL_ABGR_EXT ||
          format == GL_RGBA_INTEGER_EXT || format == GL_BGRA_INTEGER_EXT ||
          format == GL_RGB)
         return sizeof(GLuint);
      else
         return -1;
   case GL_UNSIGNED_SHORT_8_8_MESA:
   case GL_UNSIGNED_SHORT_8_8_REV_MESA:
      if (format == GL_YCBCR_MESA)
         return sizeof(GLushort);
      else
         return -1;
   case GL_UNSIGNED_INT_24_8_EXT:
      if (format == GL_DEPTH_STENCIL_EXT)
         return sizeof(GLuint);
      else
         return -1;
   case GL_UNSIGNED_INT_5_9_9_9_REV:
      if (format == GL_RGB)
         return sizeof(GLuint);
      else
         return -1;
   case GL_UNSIGNED_INT_10F_11F_11F_REV:
      if (format == GL_RGB)
         return sizeof(GLuint);
      else
         return -1;
   case GL_FLOAT_32_UNSIGNED_INT_24_8_REV:
      if (format == GL_DEPTH_STENCIL)
         return 8;
      else
         return -1;
   default:
      return -1;
   }
}


/**
 * Get the number of bytes for a vertex attrib with the given number of
 * components and type.
 *
 * \param comps number of components.
 * \param type data type.
 *
 * \return bytes per attribute, or -1 if a bad comps/type combination was given.
 */
GLint
_mesa_bytes_per_vertex_attrib(GLint comps, GLenum type)
{
   switch (type) {
   case GL_BYTE:
   case GL_UNSIGNED_BYTE:
      return comps * sizeof(GLubyte);
   case GL_SHORT:
   case GL_UNSIGNED_SHORT:
      return comps * sizeof(GLshort);
   case GL_INT:
   case GL_UNSIGNED_INT:
      return comps * sizeof(GLint);
   case GL_FLOAT:
      return comps * sizeof(GLfloat);
   case GL_HALF_FLOAT_ARB:
      return comps * sizeof(GLhalfARB);
   case GL_DOUBLE:
      return comps * sizeof(GLdouble);
   case GL_FIXED:
      return comps * sizeof(GLfixed);
   case GL_INT_2_10_10_10_REV:
   case GL_UNSIGNED_INT_2_10_10_10_REV:
      if (comps == 4)
         return sizeof(GLuint);
      else
         return -1;
   case GL_UNSIGNED_INT_10F_11F_11F_REV:
      if (comps == 3)
         return sizeof(GLuint);
      else
         return -1;
   default:
      return -1;
   }
}


/**
 * Test if the given format is an integer (non-normalized) format.
 */
GLboolean
_mesa_is_enum_format_unsigned_int(GLenum format)
{
   switch (format) {
   /* specific integer formats */
   case GL_RGBA32UI_EXT:
   case GL_RGB32UI_EXT:
   case GL_RG32UI:
   case GL_R32UI:
   case GL_ALPHA32UI_EXT:
   case GL_INTENSITY32UI_EXT:
   case GL_LUMINANCE32UI_EXT:
   case GL_LUMINANCE_ALPHA32UI_EXT:
   case GL_RGBA16UI_EXT:
   case GL_RGB16UI_EXT:
   case GL_RG16UI:
   case GL_R16UI:
   case GL_ALPHA16UI_EXT:
   case GL_INTENSITY16UI_EXT:
   case GL_LUMINANCE16UI_EXT:
   case GL_LUMINANCE_ALPHA16UI_EXT:
   case GL_RGBA8UI_EXT:
   case GL_RGB8UI_EXT:
   case GL_RG8UI:
   case GL_R8UI:
   case GL_ALPHA8UI_EXT:
   case GL_INTENSITY8UI_EXT:
   case GL_LUMINANCE8UI_EXT:
   case GL_LUMINANCE_ALPHA8UI_EXT:
   case GL_RGB10_A2UI:
      return GL_TRUE;
   default:
      return GL_FALSE;
   }
}


/**
 * Test if the given format is an integer (non-normalized) format.
 */
GLboolean
_mesa_is_enum_format_signed_int(GLenum format)
{
   switch (format) {
   /* generic integer formats */
   case GL_RED_INTEGER_EXT:
   case GL_GREEN_INTEGER_EXT:
   case GL_BLUE_INTEGER_EXT:
   case GL_ALPHA_INTEGER_EXT:
   case GL_RGB_INTEGER_EXT:
   case GL_RGBA_INTEGER_EXT:
   case GL_BGR_INTEGER_EXT:
   case GL_BGRA_INTEGER_EXT:
   case GL_LUMINANCE_INTEGER_EXT:
   case GL_LUMINANCE_ALPHA_INTEGER_EXT:
   case GL_RG_INTEGER:
   /* specific integer formats */
   case GL_RGBA32I_EXT:
   case GL_RGB32I_EXT:
   case GL_RG32I:
   case GL_R32I:
   case GL_ALPHA32I_EXT:
   case GL_INTENSITY32I_EXT:
   case GL_LUMINANCE32I_EXT:
   case GL_LUMINANCE_ALPHA32I_EXT:
   case GL_RGBA16I_EXT:
   case GL_RGB16I_EXT:
   case GL_RG16I:
   case GL_R16I:
   case GL_ALPHA16I_EXT:
   case GL_INTENSITY16I_EXT:
   case GL_LUMINANCE16I_EXT:
   case GL_LUMINANCE_ALPHA16I_EXT:
   case GL_RGBA8I_EXT:
   case GL_RGB8I_EXT:
   case GL_RG8I:
   case GL_R8I:
   case GL_ALPHA8I_EXT:
   case GL_INTENSITY8I_EXT:
   case GL_LUMINANCE8I_EXT:
   case GL_LUMINANCE_ALPHA8I_EXT:
      return GL_TRUE;
   default:
      return GL_FALSE;
   }
}


/**
 * Test if the given format is an integer (non-normalized) format.
 */
GLboolean
_mesa_is_enum_format_integer(GLenum format)
{
   return _mesa_is_enum_format_unsigned_int(format) ||
          _mesa_is_enum_format_signed_int(format);
}


/**
 * Test if the given type is an integer (non-normalized) format.
 */
GLboolean
_mesa_is_type_integer(GLenum type)
{
   switch (type) {
   case GL_INT:
   case GL_UNSIGNED_INT:
   case GL_SHORT:
   case GL_UNSIGNED_SHORT:
   case GL_BYTE:
   case GL_UNSIGNED_BYTE:
      return GL_TRUE;
   default:
      return GL_FALSE;
   }
}


/**
 * Test if the given format or type is an integer (non-normalized) format.
 */
extern GLboolean
_mesa_is_enum_format_or_type_integer(GLenum format, GLenum type)
{
   return _mesa_is_enum_format_integer(format) || _mesa_is_type_integer(type);
}


GLboolean
_mesa_is_type_unsigned(GLenum type)
{
   switch (type) {
   case GL_UNSIGNED_INT:
   case GL_UNSIGNED_INT_8_8_8_8:
   case GL_UNSIGNED_INT_8_8_8_8_REV:
   case GL_UNSIGNED_INT_10_10_10_2:
   case GL_UNSIGNED_INT_2_10_10_10_REV:

   case GL_UNSIGNED_SHORT:
   case GL_UNSIGNED_SHORT_4_4_4_4:
   case GL_UNSIGNED_SHORT_5_5_5_1:
   case GL_UNSIGNED_SHORT_5_6_5:
   case GL_UNSIGNED_SHORT_5_6_5_REV:
   case GL_UNSIGNED_SHORT_4_4_4_4_REV:
   case GL_UNSIGNED_SHORT_1_5_5_5_REV:
   case GL_UNSIGNED_SHORT_8_8_MESA:
   case GL_UNSIGNED_SHORT_8_8_REV_MESA:

   case GL_UNSIGNED_BYTE:
   case GL_UNSIGNED_BYTE_3_3_2:
   case GL_UNSIGNED_BYTE_2_3_3_REV:
      return GL_TRUE;

   default:
      return GL_FALSE;
   }
}


/**
 * Test if the given image format is a color/RGBA format (i.e., not color
 * index, depth, stencil, etc).
 * \param format  the image format value (may by an internal texture format)
 * \return GL_TRUE if its a color/RGBA format, GL_FALSE otherwise.
 */
GLboolean
_mesa_is_color_format(GLenum format)
{
   switch (format) {
      case GL_RED:
      case GL_GREEN:
      case GL_BLUE:
      case GL_ALPHA:
      case GL_ALPHA4:
      case GL_ALPHA8:
      case GL_ALPHA12:
      case GL_ALPHA16:
      case 1:
      case GL_LUMINANCE:
      case GL_LUMINANCE4:
      case GL_LUMINANCE8:
      case GL_LUMINANCE12:
      case GL_LUMINANCE16:
      case 2:
      case GL_LUMINANCE_ALPHA:
      case GL_LUMINANCE4_ALPHA4:
      case GL_LUMINANCE6_ALPHA2:
      case GL_LUMINANCE8_ALPHA8:
      case GL_LUMINANCE12_ALPHA4:
      case GL_LUMINANCE12_ALPHA12:
      case GL_LUMINANCE16_ALPHA16:
      case GL_INTENSITY:
      case GL_INTENSITY4:
      case GL_INTENSITY8:
      case GL_INTENSITY12:
      case GL_INTENSITY16:
      case GL_R8:
      case GL_R16:
      case GL_RG:
      case GL_RG8:
      case GL_RG16:
      case 3:
      case GL_RGB:
      case GL_BGR:
      case GL_R3_G3_B2:
      case GL_RGB4:
      case GL_RGB5:
      case GL_RGB565:
      case GL_RGB8:
      case GL_RGB10:
      case GL_RGB12:
      case GL_RGB16:
      case 4:
      case GL_ABGR_EXT:
      case GL_RGBA:
      case GL_BGRA:
      case GL_RGBA2:
      case GL_RGBA4:
      case GL_RGB5_A1:
      case GL_RGBA8:
      case GL_RGB10_A2:
      case GL_RGBA12:
      case GL_RGBA16:
      /* float texture formats */
      case GL_ALPHA16F_ARB:
      case GL_ALPHA32F_ARB:
      case GL_LUMINANCE16F_ARB:
      case GL_LUMINANCE32F_ARB:
      case GL_LUMINANCE_ALPHA16F_ARB:
      case GL_LUMINANCE_ALPHA32F_ARB:
      case GL_INTENSITY16F_ARB:
      case GL_INTENSITY32F_ARB:
      case GL_R16F:
      case GL_R32F:
      case GL_RG16F:
      case GL_RG32F:
      case GL_RGB16F_ARB:
      case GL_RGB32F_ARB:
      case GL_RGBA16F_ARB:
      case GL_RGBA32F_ARB:
      /* compressed formats */
      case GL_COMPRESSED_ALPHA:
      case GL_COMPRESSED_LUMINANCE:
      case GL_COMPRESSED_LUMINANCE_ALPHA:
      case GL_COMPRESSED_INTENSITY:
      case GL_COMPRESSED_RED:
      case GL_COMPRESSED_RG:
      case GL_COMPRESSED_RGB:
      case GL_COMPRESSED_RGBA:
      case GL_RGB_S3TC:
      case GL_RGB4_S3TC:
      case GL_RGBA_S3TC:
      case GL_RGBA4_S3TC:
      case GL_COMPRESSED_RGB_S3TC_DXT1_EXT:
      case GL_COMPRESSED_RGBA_S3TC_DXT1_EXT:
      case GL_COMPRESSED_RGBA_S3TC_DXT3_EXT:
      case GL_COMPRESSED_RGBA_S3TC_DXT5_EXT:
      case GL_COMPRESSED_RGB_FXT1_3DFX:
      case GL_COMPRESSED_RGBA_FXT1_3DFX:
      case GL_SRGB_EXT:
      case GL_SRGB8_EXT:
      case GL_SRGB_ALPHA_EXT:
      case GL_SRGB8_ALPHA8_EXT:
      case GL_SLUMINANCE_ALPHA_EXT:
      case GL_SLUMINANCE8_ALPHA8_EXT:
      case GL_SLUMINANCE_EXT:
      case GL_SLUMINANCE8_EXT:
      case GL_COMPRESSED_SRGB_EXT:
      case GL_COMPRESSED_SRGB_S3TC_DXT1_EXT:
      case GL_COMPRESSED_SRGB_ALPHA_EXT:
      case GL_COMPRESSED_SRGB_ALPHA_S3TC_DXT1_EXT:
      case GL_COMPRESSED_SRGB_ALPHA_S3TC_DXT3_EXT:
      case GL_COMPRESSED_SRGB_ALPHA_S3TC_DXT5_EXT:
      case GL_COMPRESSED_SLUMINANCE_EXT:
      case GL_COMPRESSED_SLUMINANCE_ALPHA_EXT:
      case GL_COMPRESSED_RED_RGTC1:
      case GL_COMPRESSED_SIGNED_RED_RGTC1:
      case GL_COMPRESSED_RG_RGTC2:
      case GL_COMPRESSED_SIGNED_RG_RGTC2:
      case GL_COMPRESSED_LUMINANCE_LATC1_EXT:
      case GL_COMPRESSED_SIGNED_LUMINANCE_LATC1_EXT:
      case GL_COMPRESSED_LUMINANCE_ALPHA_LATC2_EXT:
      case GL_COMPRESSED_SIGNED_LUMINANCE_ALPHA_LATC2_EXT:
      case GL_COMPRESSED_LUMINANCE_ALPHA_3DC_ATI:
      case GL_ETC1_RGB8_OES:
      case GL_COMPRESSED_RGB8_ETC2:
      case GL_COMPRESSED_SRGB8_ETC2:
      case GL_COMPRESSED_RGBA8_ETC2_EAC:
      case GL_COMPRESSED_SRGB8_ALPHA8_ETC2_EAC:
      case GL_COMPRESSED_R11_EAC:
      case GL_COMPRESSED_RG11_EAC:
      case GL_COMPRESSED_SIGNED_R11_EAC:
      case GL_COMPRESSED_SIGNED_RG11_EAC:
      case GL_COMPRESSED_RGB8_PUNCHTHROUGH_ALPHA1_ETC2:
      case GL_COMPRESSED_SRGB8_PUNCHTHROUGH_ALPHA1_ETC2:
      /* generic integer formats */
      case GL_RED_INTEGER_EXT:
      case GL_GREEN_INTEGER_EXT:
      case GL_BLUE_INTEGER_EXT:
      case GL_ALPHA_INTEGER_EXT:
      case GL_RGB_INTEGER_EXT:
      case GL_RGBA_INTEGER_EXT:
      case GL_BGR_INTEGER_EXT:
      case GL_BGRA_INTEGER_EXT:
      case GL_RG_INTEGER:
      case GL_LUMINANCE_INTEGER_EXT:
      case GL_LUMINANCE_ALPHA_INTEGER_EXT:
      /* sized integer formats */
      case GL_RGBA32UI_EXT:
      case GL_RGB32UI_EXT:
      case GL_RG32UI:
      case GL_R32UI:
      case GL_ALPHA32UI_EXT:
      case GL_INTENSITY32UI_EXT:
      case GL_LUMINANCE32UI_EXT:
      case GL_LUMINANCE_ALPHA32UI_EXT:
      case GL_RGBA16UI_EXT:
      case GL_RGB16UI_EXT:
      case GL_RG16UI:
      case GL_R16UI:
      case GL_ALPHA16UI_EXT:
      case GL_INTENSITY16UI_EXT:
      case GL_LUMINANCE16UI_EXT:
      case GL_LUMINANCE_ALPHA16UI_EXT:
      case GL_RGBA8UI_EXT:
      case GL_RGB8UI_EXT:
      case GL_RG8UI:
      case GL_R8UI:
      case GL_ALPHA8UI_EXT:
      case GL_INTENSITY8UI_EXT:
      case GL_LUMINANCE8UI_EXT:
      case GL_LUMINANCE_ALPHA8UI_EXT:
      case GL_RGBA32I_EXT:
      case GL_RGB32I_EXT:
      case GL_RG32I:
      case GL_R32I:
      case GL_ALPHA32I_EXT:
      case GL_INTENSITY32I_EXT:
      case GL_LUMINANCE32I_EXT:
      case GL_LUMINANCE_ALPHA32I_EXT:
      case GL_RGBA16I_EXT:
      case GL_RGB16I_EXT:
      case GL_RG16I:
      case GL_R16I:
      case GL_ALPHA16I_EXT:
      case GL_INTENSITY16I_EXT:
      case GL_LUMINANCE16I_EXT:
      case GL_LUMINANCE_ALPHA16I_EXT:
      case GL_RGBA8I_EXT:
      case GL_RGB8I_EXT:
      case GL_RG8I:
      case GL_R8I:
      case GL_ALPHA8I_EXT:
      case GL_INTENSITY8I_EXT:
      case GL_LUMINANCE8I_EXT:
      case GL_LUMINANCE_ALPHA8I_EXT:
      /* signed, normalized texture formats */
      case GL_RED_SNORM:
      case GL_R8_SNORM:
      case GL_R16_SNORM:
      case GL_RG_SNORM:
      case GL_RG8_SNORM:
      case GL_RG16_SNORM:
      case GL_RGB_SNORM:
      case GL_RGB8_SNORM:
      case GL_RGB16_SNORM:
      case GL_RGBA_SNORM:
      case GL_RGBA8_SNORM:
      case GL_RGBA16_SNORM:
      case GL_ALPHA_SNORM:
      case GL_ALPHA8_SNORM:
      case GL_ALPHA16_SNORM:
      case GL_LUMINANCE_SNORM:
      case GL_LUMINANCE8_SNORM:
      case GL_LUMINANCE16_SNORM:
      case GL_LUMINANCE_ALPHA_SNORM:
      case GL_LUMINANCE8_ALPHA8_SNORM:
      case GL_LUMINANCE16_ALPHA16_SNORM:
      case GL_INTENSITY_SNORM:
      case GL_INTENSITY8_SNORM:
      case GL_INTENSITY16_SNORM:
      case GL_RGB9_E5:
      case GL_R11F_G11F_B10F:
      case GL_RGB10_A2UI:
         return GL_TRUE;
      case GL_YCBCR_MESA:  /* not considered to be RGB */
         /* fall-through */
      default:
         return GL_FALSE;
   }
}


/**
 * Test if the given image format is a depth component format.
 */
GLboolean
_mesa_is_depth_format(GLenum format)
{
   switch (format) {
      case GL_DEPTH_COMPONENT:
      case GL_DEPTH_COMPONENT16:
      case GL_DEPTH_COMPONENT24:
      case GL_DEPTH_COMPONENT32:
      case GL_DEPTH_COMPONENT32F:
         return GL_TRUE;
      default:
         return GL_FALSE;
   }
}


/**
 * Test if the given image format is a stencil format.
 */
GLboolean
_mesa_is_stencil_format(GLenum format)
{
   switch (format) {
      case GL_STENCIL_INDEX:
         return GL_TRUE;
      default:
         return GL_FALSE;
   }
}


/**
 * Test if the given image format is a YCbCr format.
 */
GLboolean
_mesa_is_ycbcr_format(GLenum format)
{
   switch (format) {
      case GL_YCBCR_MESA:
         return GL_TRUE;
      default:
         return GL_FALSE;
   }
}


/**
 * Test if the given image format is a depth+stencil format.
 */
GLboolean
_mesa_is_depthstencil_format(GLenum format)
{
   switch (format) {
      case GL_DEPTH24_STENCIL8_EXT:
      case GL_DEPTH_STENCIL_EXT:
      case GL_DEPTH32F_STENCIL8:
         return GL_TRUE;
      default:
         return GL_FALSE;
   }
}


/**
 * Test if the given image format is a depth or stencil format.
 */
GLboolean
_mesa_is_depth_or_stencil_format(GLenum format)
{
   switch (format) {
      case GL_DEPTH_COMPONENT:
      case GL_DEPTH_COMPONENT16:
      case GL_DEPTH_COMPONENT24:
      case GL_DEPTH_COMPONENT32:
      case GL_STENCIL_INDEX:
      case GL_STENCIL_INDEX1_EXT:
      case GL_STENCIL_INDEX4_EXT:
      case GL_STENCIL_INDEX8_EXT:
      case GL_STENCIL_INDEX16_EXT:
      case GL_DEPTH_STENCIL_EXT:
      case GL_DEPTH24_STENCIL8_EXT:
      case GL_DEPTH_COMPONENT32F:
      case GL_DEPTH32F_STENCIL8:
         return GL_TRUE;
      default:
         return GL_FALSE;
   }
}


/**
 * Test if the given image format is a dudv format.
 */
GLboolean
_mesa_is_dudv_format(GLenum format)
{
   switch (format) {
      case GL_DUDV_ATI:
      case GL_DU8DV8_ATI:
         return GL_TRUE;
      default:
         return GL_FALSE;
   }
}


/**
 * Test if an image format is a supported compressed format.
 * \param format the internal format token provided by the user.
 * \return GL_TRUE if compressed, GL_FALSE if uncompressed
 */
GLboolean
_mesa_is_compressed_format(struct gl_context *ctx, GLenum format)
{
   switch (format) {
   case GL_COMPRESSED_RGB_S3TC_DXT1_EXT:
   case GL_COMPRESSED_RGBA_S3TC_DXT1_EXT:
   case GL_COMPRESSED_RGBA_S3TC_DXT3_EXT:
   case GL_COMPRESSED_RGBA_S3TC_DXT5_EXT:
      /* Assume that the ANGLE flag will always be set if the EXT flag is set.
       */
      return ctx->Extensions.ANGLE_texture_compression_dxt;
   case GL_RGB_S3TC:
   case GL_RGB4_S3TC:
   case GL_RGBA_S3TC:
   case GL_RGBA4_S3TC:
      return _mesa_is_desktop_gl(ctx) &&
         ctx->Extensions.ANGLE_texture_compression_dxt;
   case GL_COMPRESSED_SRGB_S3TC_DXT1_EXT:
   case GL_COMPRESSED_SRGB_ALPHA_S3TC_DXT1_EXT:
   case GL_COMPRESSED_SRGB_ALPHA_S3TC_DXT3_EXT:
   case GL_COMPRESSED_SRGB_ALPHA_S3TC_DXT5_EXT:
      return _mesa_is_desktop_gl(ctx)
         && ctx->Extensions.EXT_texture_sRGB
         && ctx->Extensions.EXT_texture_compression_s3tc;
   case GL_COMPRESSED_RGB_FXT1_3DFX:
   case GL_COMPRESSED_RGBA_FXT1_3DFX:
      return _mesa_is_desktop_gl(ctx)
         && ctx->Extensions.TDFX_texture_compression_FXT1;
   case GL_COMPRESSED_RED_RGTC1:
   case GL_COMPRESSED_SIGNED_RED_RGTC1:
   case GL_COMPRESSED_RG_RGTC2:
   case GL_COMPRESSED_SIGNED_RG_RGTC2:
      return _mesa_is_desktop_gl(ctx)
         && ctx->Extensions.ARB_texture_compression_rgtc;
   case GL_COMPRESSED_LUMINANCE_LATC1_EXT:
   case GL_COMPRESSED_SIGNED_LUMINANCE_LATC1_EXT:
   case GL_COMPRESSED_LUMINANCE_ALPHA_LATC2_EXT:
   case GL_COMPRESSED_SIGNED_LUMINANCE_ALPHA_LATC2_EXT:
      return ctx->API == API_OPENGL_COMPAT
         && ctx->Extensions.EXT_texture_compression_latc;
   case GL_COMPRESSED_LUMINANCE_ALPHA_3DC_ATI:
      return ctx->API == API_OPENGL_COMPAT
         && ctx->Extensions.ATI_texture_compression_3dc;
   case GL_ETC1_RGB8_OES:
      return _mesa_is_gles(ctx)
         && ctx->Extensions.OES_compressed_ETC1_RGB8_texture;
   case GL_COMPRESSED_RGB8_ETC2:
   case GL_COMPRESSED_SRGB8_ETC2:
   case GL_COMPRESSED_RGBA8_ETC2_EAC:
   case GL_COMPRESSED_SRGB8_ALPHA8_ETC2_EAC:
   case GL_COMPRESSED_R11_EAC:
   case GL_COMPRESSED_RG11_EAC:
   case GL_COMPRESSED_SIGNED_R11_EAC:
   case GL_COMPRESSED_SIGNED_RG11_EAC:
   case GL_COMPRESSED_RGB8_PUNCHTHROUGH_ALPHA1_ETC2:
   case GL_COMPRESSED_SRGB8_PUNCHTHROUGH_ALPHA1_ETC2:
      return _mesa_is_gles3(ctx) || ctx->Extensions.ARB_ES3_compatibility;
   case GL_PALETTE4_RGB8_OES:
   case GL_PALETTE4_RGBA8_OES:
   case GL_PALETTE4_R5_G6_B5_OES:
   case GL_PALETTE4_RGBA4_OES:
   case GL_PALETTE4_RGB5_A1_OES:
   case GL_PALETTE8_RGB8_OES:
   case GL_PALETTE8_RGBA8_OES:
   case GL_PALETTE8_R5_G6_B5_OES:
   case GL_PALETTE8_RGBA4_OES:
   case GL_PALETTE8_RGB5_A1_OES:
      return ctx->API == API_OPENGLES;
   default:
      return GL_FALSE;
   }
}


/**
 * Convert various base formats to the cooresponding integer format.
 */
GLenum
_mesa_base_format_to_integer_format(GLenum format)
{
   switch(format) {
   case GL_RED:
      return GL_RED_INTEGER;
   case GL_GREEN:
      return GL_GREEN_INTEGER;
   case GL_BLUE:
      return GL_BLUE_INTEGER;
   case GL_RG:
      return GL_RG_INTEGER;
   case GL_RGB:
      return GL_RGB_INTEGER;
   case GL_RGBA:
      return GL_RGBA_INTEGER;
   case GL_BGR:
      return GL_BGR_INTEGER;
   case GL_BGRA:
      return GL_BGRA_INTEGER;
   case GL_ALPHA:
      return GL_ALPHA_INTEGER;
   case GL_LUMINANCE:
      return GL_LUMINANCE_INTEGER_EXT;
   case GL_LUMINANCE_ALPHA:
      return GL_LUMINANCE_ALPHA_INTEGER_EXT;
   }

   return format;
}


/**
 * Does the given base texture/renderbuffer format have the channel
 * named by 'pname'?
 */
GLboolean
_mesa_base_format_has_channel(GLenum base_format, GLenum pname)
{
   switch (pname) {
   case GL_TEXTURE_RED_SIZE:
   case GL_TEXTURE_RED_TYPE:
   case GL_RENDERBUFFER_RED_SIZE_EXT:
   case GL_FRAMEBUFFER_ATTACHMENT_RED_SIZE:
      if (base_format == GL_RED ||
	  base_format == GL_RG ||
	  base_format == GL_RGB ||
	  base_format == GL_RGBA) {
	 return GL_TRUE;
      }
      return GL_FALSE;
   case GL_TEXTURE_GREEN_SIZE:
   case GL_TEXTURE_GREEN_TYPE:
   case GL_RENDERBUFFER_GREEN_SIZE_EXT:
   case GL_FRAMEBUFFER_ATTACHMENT_GREEN_SIZE:
      if (base_format == GL_RG ||
	  base_format == GL_RGB ||
	  base_format == GL_RGBA) {
	 return GL_TRUE;
      }
      return GL_FALSE;
   case GL_TEXTURE_BLUE_SIZE:
   case GL_TEXTURE_BLUE_TYPE:
   case GL_RENDERBUFFER_BLUE_SIZE_EXT:
   case GL_FRAMEBUFFER_ATTACHMENT_BLUE_SIZE:
      if (base_format == GL_RGB ||
	  base_format == GL_RGBA) {
	 return GL_TRUE;
      }
      return GL_FALSE;
   case GL_TEXTURE_ALPHA_SIZE:
   case GL_TEXTURE_ALPHA_TYPE:
   case GL_RENDERBUFFER_ALPHA_SIZE_EXT:
   case GL_FRAMEBUFFER_ATTACHMENT_ALPHA_SIZE:
      if (base_format == GL_RGBA ||
	  base_format == GL_ALPHA ||
	  base_format == GL_LUMINANCE_ALPHA) {
	 return GL_TRUE;
      }
      return GL_FALSE;
   case GL_TEXTURE_LUMINANCE_SIZE:
   case GL_TEXTURE_LUMINANCE_TYPE:
      if (base_format == GL_LUMINANCE ||
	  base_format == GL_LUMINANCE_ALPHA) {
	 return GL_TRUE;
      }
      return GL_FALSE;
   case GL_TEXTURE_INTENSITY_SIZE:
   case GL_TEXTURE_INTENSITY_TYPE:
      if (base_format == GL_INTENSITY) {
	 return GL_TRUE;
      }
      return GL_FALSE;
   case GL_TEXTURE_DEPTH_SIZE:
   case GL_TEXTURE_DEPTH_TYPE:
   case GL_RENDERBUFFER_DEPTH_SIZE_EXT:
   case GL_FRAMEBUFFER_ATTACHMENT_DEPTH_SIZE:
      if (base_format == GL_DEPTH_STENCIL ||
	  base_format == GL_DEPTH_COMPONENT) {
	 return GL_TRUE;
      }
      return GL_FALSE;
   case GL_RENDERBUFFER_STENCIL_SIZE_EXT:
   case GL_FRAMEBUFFER_ATTACHMENT_STENCIL_SIZE:
      if (base_format == GL_DEPTH_STENCIL ||
	  base_format == GL_STENCIL_INDEX) {
	 return GL_TRUE;
      }
      return GL_FALSE;
   default:
      _mesa_warning(NULL, "%s: Unexpected channel token 0x%x\n",
		    __FUNCTION__, pname);
      return GL_FALSE;
   }

   return GL_FALSE;
}


/**
 * Returns the number of channels/components for a base format.
 */
GLint
_mesa_base_format_component_count(GLenum base_format)
{
   switch (base_format) {
   case GL_RED:
   case GL_ALPHA:
   case GL_INTENSITY:
   case GL_DEPTH_COMPONENT:
      return 1;
   case GL_RG:
   case GL_LUMINANCE_ALPHA:
   case GL_DEPTH_STENCIL:
      return 2;
   case GL_RGB:
      return 3;
   case GL_RGBA:
      return 4;
   default:
      return -1;
   }
}


/**
 * If format is a generic compressed format, return the corresponding
 * non-compressed format.  For other formats, return the format as-is.
 */
GLenum
_mesa_generic_compressed_format_to_uncompressed_format(GLenum format)
{
   switch (format) {
   case GL_COMPRESSED_RED:
      return GL_RED;
   case GL_COMPRESSED_RG:
      return GL_RG;
   case GL_COMPRESSED_RGB:
      return GL_RGB;
   case GL_COMPRESSED_RGBA:
      return GL_RGBA;
   case GL_COMPRESSED_ALPHA:
      return GL_ALPHA;
   case GL_COMPRESSED_LUMINANCE:
      return GL_LUMINANCE;
   case GL_COMPRESSED_LUMINANCE_ALPHA:
      return GL_LUMINANCE_ALPHA;
   case GL_COMPRESSED_INTENSITY:
      return GL_INTENSITY;
   /* sRGB formats */
   case GL_COMPRESSED_SRGB:
      return GL_SRGB;
   case GL_COMPRESSED_SRGB_ALPHA:
      return GL_SRGB_ALPHA;
   case GL_COMPRESSED_SLUMINANCE:
      return GL_SLUMINANCE;
   case GL_COMPRESSED_SLUMINANCE_ALPHA:
      return GL_SLUMINANCE_ALPHA;
   default:
      return format;
   }
}


/**
 * Return the equivalent non-generic internal format.
 * This is useful for comparing whether two internal formats are equivalent.
 */
GLenum
_mesa_get_nongeneric_internalformat(GLenum format)
{
   switch (format) {
   /* GL 1.1 formats. */
   case 4:
   case GL_RGBA:
      return GL_RGBA8;
   case 3:
   case GL_RGB:
      return GL_RGB8;
   case 2:
   case GL_LUMINANCE_ALPHA:
      return GL_LUMINANCE8_ALPHA8;
   case 1:
   case GL_LUMINANCE:
      return GL_LUMINANCE8;
   case GL_ALPHA:
      return GL_ALPHA8;
   case GL_INTENSITY:
      return GL_INTENSITY8;

   /* GL_ARB_texture_rg */
   case GL_RED:
      return GL_R8;
   case GL_RG:
      return GL_RG8;

   /* GL_EXT_texture_sRGB */
   case GL_SRGB:
      return GL_SRGB8;
   case GL_SRGB_ALPHA:
      return GL_SRGB8_ALPHA8;
   case GL_SLUMINANCE:
      return GL_SLUMINANCE8;
   case GL_SLUMINANCE_ALPHA:
      return GL_SLUMINANCE8_ALPHA8;

   /* GL_EXT_texture_snorm */
   case GL_RGBA_SNORM:
      return GL_RGBA8_SNORM;
   case GL_RGB_SNORM:
      return GL_RGB8_SNORM;
   case GL_RG_SNORM:
      return GL_RG8_SNORM;
   case GL_RED_SNORM:
      return GL_R8_SNORM;
   case GL_LUMINANCE_ALPHA_SNORM:
      return GL_LUMINANCE8_ALPHA8_SNORM;
   case GL_LUMINANCE_SNORM:
      return GL_LUMINANCE8_SNORM;
   case GL_ALPHA_SNORM:
      return GL_ALPHA8_SNORM;
   case GL_INTENSITY_SNORM:
      return GL_INTENSITY8_SNORM;

   default:
      return format;
   }
}


/**
 * Convert an sRGB internal format to linear.
 */
GLenum
_mesa_get_linear_internalformat(GLenum format)
{
   switch (format) {
   case GL_SRGB:
      return GL_RGB;
   case GL_SRGB_ALPHA:
      return GL_RGBA;
   case GL_SRGB8:
      return GL_RGB8;
   case GL_SRGB8_ALPHA8:
      return GL_RGBA8;
   case GL_SLUMINANCE8:
      return GL_LUMINANCE8;
   case GL_SLUMINANCE:
      return GL_LUMINANCE;
   case GL_SLUMINANCE_ALPHA:
      return GL_LUMINANCE_ALPHA;
   case GL_SLUMINANCE8_ALPHA8:
      return GL_LUMINANCE8_ALPHA8;
   default:
      return format;
   }
}


/**
 * Do error checking of format/type combinations for glReadPixels,
 * glDrawPixels and glTex[Sub]Image.  Note that depending on the format
 * and type values, we may either generate GL_INVALID_OPERATION or
 * GL_INVALID_ENUM.
 *
 * \param format pixel format.
 * \param type pixel type.
 *
 * \return GL_INVALID_ENUM, GL_INVALID_OPERATION or GL_NO_ERROR
 */
GLenum
_mesa_error_check_format_and_type(const struct gl_context *ctx,
                                  GLenum format, GLenum type)
{
   /* From OpenGL 3.3 spec, page 220:
    *    "If the format is DEPTH_STENCIL, then values are taken from
    *    both the depth buffer and the stencil buffer. If there is no
    *    depth buffer or if there is no stencil buffer, then the error
    *    INVALID_OPERATION occurs. If the type parameter is not
    *    UNSIGNED_INT_24_8 or FLOAT_32_UNSIGNED_INT_24_8_REV, then the
    *    error INVALID_ENUM occurs."
    *
    * OpenGL ES still generates GL_INVALID_OPERATION because glReadPixels
    * cannot be used to read depth or stencil in that API.
    */
   if (_mesa_is_desktop_gl(ctx) && format == GL_DEPTH_STENCIL
       && type != GL_UNSIGNED_INT_24_8
       && type != GL_FLOAT_32_UNSIGNED_INT_24_8_REV)
      return GL_INVALID_ENUM;

   /* special type-based checks (see glReadPixels, glDrawPixels error lists) */
   switch (type) {
   case GL_BITMAP:
      if (format != GL_COLOR_INDEX && format != GL_STENCIL_INDEX) {
         return GL_INVALID_ENUM;
      }
      break;

   case GL_UNSIGNED_BYTE_3_3_2:
   case GL_UNSIGNED_BYTE_2_3_3_REV:
   case GL_UNSIGNED_SHORT_5_6_5:
   case GL_UNSIGNED_SHORT_5_6_5_REV:
      if (format == GL_RGB) {
         break; /* OK */
      }
      if (format == GL_RGB_INTEGER_EXT &&
          ctx->Extensions.ARB_texture_rgb10_a2ui) {
         break; /* OK */
      }
      return GL_INVALID_OPERATION;

   case GL_UNSIGNED_SHORT_4_4_4_4:
   case GL_UNSIGNED_SHORT_4_4_4_4_REV:
   case GL_UNSIGNED_SHORT_5_5_5_1:
   case GL_UNSIGNED_SHORT_1_5_5_5_REV:
   case GL_UNSIGNED_INT_8_8_8_8:
   case GL_UNSIGNED_INT_8_8_8_8_REV:
   case GL_UNSIGNED_INT_10_10_10_2:
   case GL_UNSIGNED_INT_2_10_10_10_REV:
      if (format == GL_RGBA ||
          format == GL_BGRA ||
          format == GL_ABGR_EXT) {
         break; /* OK */
      }
      if ((format == GL_RGBA_INTEGER_EXT || format == GL_BGRA_INTEGER_EXT) &&
          ctx->Extensions.ARB_texture_rgb10_a2ui) {
         break; /* OK */
      }
      if (type == GL_UNSIGNED_INT_2_10_10_10_REV && format == GL_RGB &&
          ctx->API == API_OPENGLES2) {
         break; /* OK by GL_EXT_texture_type_2_10_10_10_REV */
      }
      return GL_INVALID_OPERATION;

   case GL_UNSIGNED_INT_24_8:
      if (format != GL_DEPTH_STENCIL) {
         return GL_INVALID_OPERATION;
      }
      return GL_NO_ERROR;

   case GL_FLOAT_32_UNSIGNED_INT_24_8_REV:
      if (!ctx->Extensions.ARB_depth_buffer_float) {
         return GL_INVALID_ENUM;
      }
      if (format != GL_DEPTH_STENCIL) {
         return GL_INVALID_OPERATION;
      }
      return GL_NO_ERROR;

   case GL_UNSIGNED_INT_10F_11F_11F_REV:
      if (!ctx->Extensions.EXT_packed_float) {
         return GL_INVALID_ENUM;
      }
      if (format != GL_RGB) {
         return GL_INVALID_OPERATION;
      }
      return GL_NO_ERROR;

   default:
      ; /* fall-through */
   }

   /* now, for each format, check the type for compatibility */
   switch (format) {
      case GL_COLOR_INDEX:
      case GL_STENCIL_INDEX:
         switch (type) {
            case GL_BITMAP:
            case GL_BYTE:
            case GL_UNSIGNED_BYTE:
            case GL_SHORT:
            case GL_UNSIGNED_SHORT:
            case GL_INT:
            case GL_UNSIGNED_INT:
            case GL_FLOAT:
            case GL_HALF_FLOAT:
               return GL_NO_ERROR;
            default:
               return GL_INVALID_ENUM;
         }

      case GL_RED:
      case GL_GREEN:
      case GL_BLUE:
      case GL_ALPHA:
#if 0 /* not legal!  see table 3.6 of the 1.5 spec */
      case GL_INTENSITY:
#endif
      case GL_LUMINANCE:
      case GL_LUMINANCE_ALPHA:
      case GL_DEPTH_COMPONENT:
         switch (type) {
            case GL_BYTE:
            case GL_UNSIGNED_BYTE:
            case GL_SHORT:
            case GL_UNSIGNED_SHORT:
            case GL_INT:
            case GL_UNSIGNED_INT:
            case GL_FLOAT:
            case GL_HALF_FLOAT:
               return GL_NO_ERROR;
            default:
               return GL_INVALID_ENUM;
         }

      case GL_RG:
	 if (!ctx->Extensions.ARB_texture_rg)
	    return GL_INVALID_ENUM;
         switch (type) {
            case GL_BYTE:
            case GL_UNSIGNED_BYTE:
            case GL_SHORT:
            case GL_UNSIGNED_SHORT:
            case GL_INT:
            case GL_UNSIGNED_INT:
            case GL_FLOAT:
            case GL_HALF_FLOAT:
               return GL_NO_ERROR;
            default:
               return GL_INVALID_ENUM;
         }

      case GL_RGB:
         switch (type) {
            case GL_BYTE:
            case GL_UNSIGNED_BYTE:
            case GL_SHORT:
            case GL_UNSIGNED_SHORT:
            case GL_INT:
            case GL_UNSIGNED_INT:
            case GL_FLOAT:
            case GL_UNSIGNED_BYTE_3_3_2:
            case GL_UNSIGNED_BYTE_2_3_3_REV:
            case GL_UNSIGNED_SHORT_5_6_5:
            case GL_UNSIGNED_SHORT_5_6_5_REV:
            case GL_HALF_FLOAT:
               return GL_NO_ERROR;
            case GL_UNSIGNED_INT_2_10_10_10_REV:
               /* OK by GL_EXT_texture_type_2_10_10_10_REV */
               return (ctx->API == API_OPENGLES2)
                  ? GL_NO_ERROR : GL_INVALID_ENUM;
            case GL_UNSIGNED_INT_5_9_9_9_REV:
               return ctx->Extensions.EXT_texture_shared_exponent
                  ? GL_NO_ERROR : GL_INVALID_ENUM;
            case GL_UNSIGNED_INT_10F_11F_11F_REV:
               return ctx->Extensions.EXT_packed_float
                  ? GL_NO_ERROR : GL_INVALID_ENUM;
            default:
               return GL_INVALID_ENUM;
         }

      case GL_BGR:
         switch (type) {
            /* NOTE: no packed types are supported with BGR.  That's
             * intentional, according to the GL spec.
             */
            case GL_BYTE:
            case GL_UNSIGNED_BYTE:
            case GL_SHORT:
            case GL_UNSIGNED_SHORT:
            case GL_INT:
            case GL_UNSIGNED_INT:
            case GL_FLOAT:
            case GL_HALF_FLOAT:
               return GL_NO_ERROR;
            default:
               return GL_INVALID_ENUM;
         }

      case GL_RGBA:
      case GL_BGRA:
      case GL_ABGR_EXT:
         switch (type) {
            case GL_BYTE:
            case GL_UNSIGNED_BYTE:
            case GL_SHORT:
            case GL_UNSIGNED_SHORT:
            case GL_INT:
            case GL_UNSIGNED_INT:
            case GL_FLOAT:
            case GL_UNSIGNED_SHORT_4_4_4_4:
            case GL_UNSIGNED_SHORT_4_4_4_4_REV:
            case GL_UNSIGNED_SHORT_5_5_5_1:
            case GL_UNSIGNED_SHORT_1_5_5_5_REV:
            case GL_UNSIGNED_INT_8_8_8_8:
            case GL_UNSIGNED_INT_8_8_8_8_REV:
            case GL_UNSIGNED_INT_10_10_10_2:
            case GL_UNSIGNED_INT_2_10_10_10_REV:
            case GL_HALF_FLOAT:
               return GL_NO_ERROR;
            default:
               return GL_INVALID_ENUM;
         }

      case GL_YCBCR_MESA:
         if (!ctx->Extensions.MESA_ycbcr_texture)
            return GL_INVALID_ENUM;
         if (type == GL_UNSIGNED_SHORT_8_8_MESA ||
             type == GL_UNSIGNED_SHORT_8_8_REV_MESA)
            return GL_NO_ERROR;
         else
            return GL_INVALID_OPERATION;

      case GL_DEPTH_STENCIL:
         if (type == GL_UNSIGNED_INT_24_8)
            return GL_NO_ERROR;
         else if (ctx->Extensions.ARB_depth_buffer_float &&
             type == GL_FLOAT_32_UNSIGNED_INT_24_8_REV)
            return GL_NO_ERROR;
         else
            return GL_INVALID_ENUM;

      case GL_DUDV_ATI:
      case GL_DU8DV8_ATI:
         if (!ctx->Extensions.ATI_envmap_bumpmap)
            return GL_INVALID_ENUM;
         switch (type) {
            case GL_BYTE:
            case GL_UNSIGNED_BYTE:
            case GL_SHORT:
            case GL_UNSIGNED_SHORT:
            case GL_INT:
            case GL_UNSIGNED_INT:
            case GL_FLOAT:
               return GL_NO_ERROR;
            default:
               return GL_INVALID_ENUM;
         }

      /* integer-valued formats */
      case GL_RED_INTEGER_EXT:
      case GL_GREEN_INTEGER_EXT:
      case GL_BLUE_INTEGER_EXT:
      case GL_ALPHA_INTEGER_EXT:
      case GL_RG_INTEGER:
         switch (type) {
            case GL_BYTE:
            case GL_UNSIGNED_BYTE:
            case GL_SHORT:
            case GL_UNSIGNED_SHORT:
            case GL_INT:
            case GL_UNSIGNED_INT:
               return (ctx->Version >= 30 ||
                       ctx->Extensions.EXT_texture_integer)
                  ? GL_NO_ERROR : GL_INVALID_ENUM;
            default:
               return GL_INVALID_ENUM;
         }

      case GL_RGB_INTEGER_EXT:
         switch (type) {
            case GL_BYTE:
            case GL_UNSIGNED_BYTE:
            case GL_SHORT:
            case GL_UNSIGNED_SHORT:
            case GL_INT:
            case GL_UNSIGNED_INT:
               return (ctx->Version >= 30 ||
                       ctx->Extensions.EXT_texture_integer)
                  ? GL_NO_ERROR : GL_INVALID_ENUM;
            case GL_UNSIGNED_BYTE_3_3_2:
            case GL_UNSIGNED_BYTE_2_3_3_REV:
            case GL_UNSIGNED_SHORT_5_6_5:
            case GL_UNSIGNED_SHORT_5_6_5_REV:
               return ctx->Extensions.ARB_texture_rgb10_a2ui
                  ? GL_NO_ERROR : GL_INVALID_ENUM;
            default:
               return GL_INVALID_ENUM;
         }

      case GL_BGR_INTEGER_EXT:
         switch (type) {
            case GL_BYTE:
            case GL_UNSIGNED_BYTE:
            case GL_SHORT:
            case GL_UNSIGNED_SHORT:
            case GL_INT:
            case GL_UNSIGNED_INT:
            /* NOTE: no packed formats w/ BGR format */
               return (ctx->Version >= 30 ||
                       ctx->Extensions.EXT_texture_integer)
                  ? GL_NO_ERROR : GL_INVALID_ENUM;
            default:
               return GL_INVALID_ENUM;
         }

      case GL_RGBA_INTEGER_EXT:
      case GL_BGRA_INTEGER_EXT:
         switch (type) {
            case GL_BYTE:
            case GL_UNSIGNED_BYTE:
            case GL_SHORT:
            case GL_UNSIGNED_SHORT:
            case GL_INT:
            case GL_UNSIGNED_INT:
               return (ctx->Version >= 30 ||
                       ctx->Extensions.EXT_texture_integer)
                  ? GL_NO_ERROR : GL_INVALID_ENUM;
            case GL_UNSIGNED_SHORT_4_4_4_4:
            case GL_UNSIGNED_SHORT_4_4_4_4_REV:
            case GL_UNSIGNED_SHORT_5_5_5_1:
            case GL_UNSIGNED_SHORT_1_5_5_5_REV:
            case GL_UNSIGNED_INT_8_8_8_8:
            case GL_UNSIGNED_INT_8_8_8_8_REV:
            case GL_UNSIGNED_INT_10_10_10_2:
            case GL_UNSIGNED_INT_2_10_10_10_REV:
               return ctx->Extensions.ARB_texture_rgb10_a2ui
                  ? GL_NO_ERROR : GL_INVALID_ENUM;
            default:
               return GL_INVALID_ENUM;
         }

      case GL_LUMINANCE_INTEGER_EXT:
      case GL_LUMINANCE_ALPHA_INTEGER_EXT:
         switch (type) {
            case GL_BYTE:
            case GL_UNSIGNED_BYTE:
            case GL_SHORT:
            case GL_UNSIGNED_SHORT:
            case GL_INT:
            case GL_UNSIGNED_INT:
               return ctx->Extensions.EXT_texture_integer
                  ? GL_NO_ERROR : GL_INVALID_ENUM;
            default:
               return GL_INVALID_ENUM;
         }

      default:
         return GL_INVALID_ENUM;
   }
   return GL_NO_ERROR;
}


/**
 * Do error checking of format/type combinations for OpenGL ES glReadPixels
 * and glTex[Sub]Image.
 * \return error code, or GL_NO_ERROR.
 */
GLenum
_mesa_es_error_check_format_and_type(GLenum format, GLenum type,
                                     unsigned dimensions)
{
   GLboolean type_valid = GL_TRUE;

   switch (format) {
   case GL_ALPHA:
   case GL_LUMINANCE:
   case GL_LUMINANCE_ALPHA:
      type_valid = (type == GL_UNSIGNED_BYTE
                    || type == GL_FLOAT
                    || type == GL_HALF_FLOAT_OES);
      break;

   case GL_RGB:
      type_valid = (type == GL_UNSIGNED_BYTE
                    || type == GL_UNSIGNED_SHORT_5_6_5
                    || type == GL_FLOAT
                    || type == GL_HALF_FLOAT_OES);
      break;

   case GL_RGBA:
      type_valid = (type == GL_UNSIGNED_BYTE
                    || type == GL_UNSIGNED_SHORT_4_4_4_4
                    || type == GL_UNSIGNED_SHORT_5_5_5_1
                    || type == GL_FLOAT
                    || type == GL_HALF_FLOAT_OES
                    || type == GL_UNSIGNED_INT_2_10_10_10_REV);
      break;

   case GL_DEPTH_COMPONENT:
      /* This format is filtered against invalid dimensionalities elsewhere.
       */
      type_valid = (type == GL_UNSIGNED_SHORT
                    || type == GL_UNSIGNED_INT);
      break;

   case GL_DEPTH_STENCIL:
      /* This format is filtered against invalid dimensionalities elsewhere.
       */
      type_valid = (type == GL_UNSIGNED_INT_24_8);
      break;

   case GL_BGRA_EXT:
      type_valid = (type == GL_UNSIGNED_BYTE);

      /* This feels like a bug in the EXT_texture_format_BGRA8888 spec, but
       * the format does not appear to be allowed for 3D textures in OpenGL
       * ES.
       */
      if (dimensions != 2)
         return GL_INVALID_VALUE;

      break;

   default:
      return GL_INVALID_VALUE;
   }

   return type_valid ? GL_NO_ERROR : GL_INVALID_OPERATION;
}


/**
 * Do error checking of format/type combinations for OpenGL ES 3
 * glTex[Sub]Image.
 * \return error code, or GL_NO_ERROR.
 */
GLenum
_mesa_es3_error_check_format_and_type(GLenum format, GLenum type,
                                      GLenum internalFormat)
{
   switch (format) {
   case GL_RGBA:
      switch (type) {
      case GL_UNSIGNED_BYTE:
         switch (internalFormat) {
         case GL_RGBA:
         case GL_RGBA8:
         case GL_RGB5_A1:
         case GL_RGBA4:
         case GL_SRGB8_ALPHA8_EXT:
            break;
         default:
            return GL_INVALID_OPERATION;
         }
         break;

      case GL_BYTE:
         if (internalFormat != GL_RGBA8_SNORM)
            return GL_INVALID_OPERATION;
         break;

      case GL_UNSIGNED_SHORT_4_4_4_4:
         switch (internalFormat) {
         case GL_RGBA:
         case GL_RGBA4:
            break;
         default:
            return GL_INVALID_OPERATION;
         }
         break;

      case GL_UNSIGNED_SHORT_5_5_5_1:
         switch (internalFormat) {
         case GL_RGBA:
         case GL_RGB5_A1:
            break;
         default:
            return GL_INVALID_OPERATION;
         }
         break;

      case GL_UNSIGNED_INT_2_10_10_10_REV:
         switch (internalFormat) {
         case GL_RGBA: /* GL_EXT_texture_type_2_10_10_10_REV */
         case GL_RGB10_A2:
         case GL_RGB5_A1:
            break;
         default:
            return GL_INVALID_OPERATION;
         }
         break;

      case GL_HALF_FLOAT:
         if (internalFormat != GL_RGBA16F)
            return GL_INVALID_OPERATION;
         break;

      case GL_FLOAT:
         switch (internalFormat) {
         case GL_RGBA16F:
         case GL_RGBA32F:
            break;
         default:
            return GL_INVALID_OPERATION;
         }
         break;

      default:
         return GL_INVALID_OPERATION;
      }
      break;

   case GL_RGBA_INTEGER:
      switch (type) {
      case GL_UNSIGNED_BYTE:
         if (internalFormat != GL_RGBA8UI)
            return GL_INVALID_OPERATION;
         break;

      case GL_BYTE:
         if (internalFormat != GL_RGBA8I)
            return GL_INVALID_OPERATION;
         break;

      case GL_UNSIGNED_SHORT:
         if (internalFormat != GL_RGBA16UI)
            return GL_INVALID_OPERATION;
         break;

      case GL_SHORT:
         if (internalFormat != GL_RGBA16I)
            return GL_INVALID_OPERATION;
         break;

      case GL_UNSIGNED_INT:
         if (internalFormat != GL_RGBA32UI)
            return GL_INVALID_OPERATION;
         break;

      case GL_INT:
         if (internalFormat != GL_RGBA32I)
            return GL_INVALID_OPERATION;
         break;

      case GL_UNSIGNED_INT_2_10_10_10_REV:
         if (internalFormat != GL_RGB10_A2UI)
            return GL_INVALID_OPERATION;
         break;

      default:
         return GL_INVALID_OPERATION;
      }
      break;

   case GL_RGB:
      switch (type) {
      case GL_UNSIGNED_BYTE:
         switch (internalFormat) {
         case GL_RGB:
         case GL_RGB8:
         case GL_RGB565:
         case GL_SRGB8:
            break;
         default:
            return GL_INVALID_OPERATION;
         }
         break;

      case GL_BYTE:
         if (internalFormat != GL_RGB8_SNORM)
            return GL_INVALID_OPERATION;
         break;

      case GL_UNSIGNED_SHORT_5_6_5:
         switch (internalFormat) {
         case GL_RGB:
         case GL_RGB565:
            break;
         default:
            return GL_INVALID_OPERATION;
         }
         break;

      case GL_UNSIGNED_INT_10F_11F_11F_REV:
         if (internalFormat != GL_R11F_G11F_B10F)
            return GL_INVALID_OPERATION;
         break;

      case GL_UNSIGNED_INT_5_9_9_9_REV:
         if (internalFormat != GL_RGB9_E5)
            return GL_INVALID_OPERATION;
         break;

      case GL_HALF_FLOAT:
         switch (internalFormat) {
         case GL_RGB16F:
         case GL_R11F_G11F_B10F:
         case GL_RGB9_E5:
            break;
         default:
            return GL_INVALID_OPERATION;
         }
         break;

      case GL_FLOAT:
         switch (internalFormat) {
         case GL_RGB16F:
         case GL_RGB32F:
         case GL_R11F_G11F_B10F:
         case GL_RGB9_E5:
            break;
         default:
            return GL_INVALID_OPERATION;
         }
         break;

      case GL_UNSIGNED_INT_2_10_10_10_REV:
         switch (internalFormat) {
         case GL_RGB: /* GL_EXT_texture_type_2_10_10_10_REV */
            break;
         default:
            return GL_INVALID_OPERATION;
         }
         break;

      default:
         return GL_INVALID_OPERATION;
      }
      break;

   case GL_RGB_INTEGER:
      switch (type) {
      case GL_UNSIGNED_BYTE:
         if (internalFormat != GL_RGB8UI)
            return GL_INVALID_OPERATION;
         break;

      case GL_BYTE:
         if (internalFormat != GL_RGB8I)
            return GL_INVALID_OPERATION;
         break;

      case GL_UNSIGNED_SHORT:
         if (internalFormat != GL_RGB16UI)
            return GL_INVALID_OPERATION;
         break;

      case GL_SHORT:
         if (internalFormat != GL_RGB16I)
            return GL_INVALID_OPERATION;
         break;

      case GL_UNSIGNED_INT:
         if (internalFormat != GL_RGB32UI)
            return GL_INVALID_OPERATION;
         break;

      case GL_INT:
         if (internalFormat != GL_RGB32I)
            return GL_INVALID_OPERATION;
         break;

      default:
         return GL_INVALID_OPERATION;
      }
      break;

   case GL_RG:
      switch (type) {
      case GL_UNSIGNED_BYTE:
         if (internalFormat != GL_RG8)
            return GL_INVALID_OPERATION;
         break;

      case GL_BYTE:
         if (internalFormat != GL_RG8_SNORM)
            return GL_INVALID_OPERATION;
         break;

      case GL_HALF_FLOAT:
         if (internalFormat != GL_RG16F)
            return GL_INVALID_OPERATION;
         break;

      case GL_FLOAT:
         switch (internalFormat) {
         case GL_RG16F:
         case GL_RG32F:
            break;
         default:
            return GL_INVALID_OPERATION;
         }
         break;

      default:
         return GL_INVALID_OPERATION;
      }
      break;

   case GL_RG_INTEGER:
      switch (type) {
      case GL_UNSIGNED_BYTE:
         if (internalFormat != GL_RG8UI)
            return GL_INVALID_OPERATION;
         break;

      case GL_BYTE:
         if (internalFormat != GL_RG8I)
            return GL_INVALID_OPERATION;
         break;

      case GL_UNSIGNED_SHORT:
         if (internalFormat != GL_RG16UI)
            return GL_INVALID_OPERATION;
         break;

      case GL_SHORT:
         if (internalFormat != GL_RG16I)
            return GL_INVALID_OPERATION;
         break;

      case GL_UNSIGNED_INT:
         if (internalFormat != GL_RG32UI)
            return GL_INVALID_OPERATION;
         break;

      case GL_INT:
         if (internalFormat != GL_RG32I)
            return GL_INVALID_OPERATION;
         break;

      default:
         return GL_INVALID_OPERATION;
      }
      break;

   case GL_RED:
      switch (type) {
      case GL_UNSIGNED_BYTE:
         if (internalFormat != GL_R8)
            return GL_INVALID_OPERATION;
         break;

      case GL_BYTE:
         if (internalFormat != GL_R8_SNORM)
            return GL_INVALID_OPERATION;
         break;

      case GL_HALF_FLOAT:
         if (internalFormat != GL_R16F)
            return GL_INVALID_OPERATION;
         break;

      case GL_FLOAT:
         switch (internalFormat) {
         case GL_R16F:
         case GL_R32F:
            break;
         default:
            return GL_INVALID_OPERATION;
         }
         break;

      default:
         return GL_INVALID_OPERATION;
      }
      break;

   case GL_RED_INTEGER:
      switch (type) {
      case GL_UNSIGNED_BYTE:
         if (internalFormat != GL_R8UI)
            return GL_INVALID_OPERATION;
         break;

      case GL_BYTE:
         if (internalFormat != GL_R8I)
            return GL_INVALID_OPERATION;
         break;

      case GL_UNSIGNED_SHORT:
         if (internalFormat != GL_R16UI)
            return GL_INVALID_OPERATION;
         break;

      case GL_SHORT:
         if (internalFormat != GL_R16I)
            return GL_INVALID_OPERATION;
         break;

      case GL_UNSIGNED_INT:
         if (internalFormat != GL_R32UI)
            return GL_INVALID_OPERATION;
         break;

      case GL_INT:
         if (internalFormat != GL_R32I)
            return GL_INVALID_OPERATION;
         break;

      default:
         return GL_INVALID_OPERATION;
      }
      break;

   case GL_DEPTH_COMPONENT:
      switch (type) {
      case GL_UNSIGNED_SHORT:
         if (internalFormat != GL_DEPTH_COMPONENT
             && internalFormat != GL_DEPTH_COMPONENT16)
            return GL_INVALID_OPERATION;
         break;

      case GL_UNSIGNED_INT:
         switch (internalFormat) {
         case GL_DEPTH_COMPONENT:
         case GL_DEPTH_COMPONENT16:
         case GL_DEPTH_COMPONENT24:
            break;
         default:
            return GL_INVALID_OPERATION;
         }
         break;

      case GL_FLOAT:
         if (internalFormat != GL_DEPTH_COMPONENT32F)
            return GL_INVALID_OPERATION;
         break;

      default:
         return GL_INVALID_OPERATION;
      }
      break;

   case GL_DEPTH_STENCIL:
      switch (type) {
      case GL_UNSIGNED_INT_24_8:
         if (internalFormat != GL_DEPTH_STENCIL
             && internalFormat != GL_DEPTH24_STENCIL8)
            return GL_INVALID_OPERATION;
         break;

      case GL_FLOAT_32_UNSIGNED_INT_24_8_REV:
         if (internalFormat != GL_DEPTH32F_STENCIL8)
            return GL_INVALID_OPERATION;
         break;

      default:
         return GL_INVALID_OPERATION;
      }
      break;

   case GL_ALPHA:
   case GL_LUMINANCE:
   case GL_LUMINANCE_ALPHA:
      if (type != GL_UNSIGNED_BYTE || format != internalFormat)
         return GL_INVALID_OPERATION;
      break;
   }

   return GL_NO_ERROR;
}