// File: crn_etc.cpp // See Copyright Notice and license at the end of inc/crnlib.h #include "crn_core.h" #include "crn_etc.h" #include "crn_radix_sort.h" #include "crn_ryg_dxt.hpp" namespace crnlib { const int g_etc1_inten_tables[cETC1IntenModifierValues][cETC1SelectorValues] = { { -8, -2, 2, 8 }, { -17, -5, 5, 17 }, { -29, -9, 9, 29 }, { -42, -13, 13, 42 }, { -60, -18, 18, 60 }, { -80, -24, 24, 80 }, { -106, -33, 33, 106 }, { -183, -47, 47, 183 } }; const uint8 g_etc1_to_selector_index[cETC1SelectorValues] = { 2, 3, 1, 0 }; const uint8 g_selector_index_to_etc1[cETC1SelectorValues] = { 3, 2, 0, 1 }; // [flip][subblock][pixel_index] const etc1_coord2 g_etc1_pixel_coords[2][2][8] = { { { { 0, 0 }, { 0, 1 }, { 0, 2 }, { 0, 3 }, { 1, 0 }, { 1, 1 }, { 1, 2 }, { 1, 3 } }, { { 2, 0 }, { 2, 1 }, { 2, 2 }, { 2, 3 }, { 3, 0 }, { 3, 1 }, { 3, 2 }, { 3, 3 } } }, { { { 0, 0 }, { 1, 0 }, { 2, 0 }, { 3, 0 }, { 0, 1 }, { 1, 1 }, { 2, 1 }, { 3, 1 } }, { { 0, 2 }, { 1, 2 }, { 2, 2 }, { 3, 2 }, { 0, 3 }, { 1, 3 }, { 2, 3 }, { 3, 3 } }, } }; // Given an ETC1 diff/inten_table/selector, and an 8-bit desired color, this table encodes the best packed_color in the low byte, and the abs error in the high byte. static uint16 g_etc1_inverse_lookup[2*8*4][256]; // [diff/inten_table/selector][desired_color] // g_color8_to_etc_block_config[color][table_index] = Supplies for each 8-bit color value a list of packed ETC1 diff/intensity table/selectors/packed_colors that map to that color. // To pack: diff | (inten << 1) | (selector << 4) | (packed_c << 8) static const uint16 g_color8_to_etc_block_config_0_255[2][33] = { { 0x0000, 0x0010, 0x0002, 0x0012, 0x0004, 0x0014, 0x0006, 0x0016, 0x0008, 0x0018, 0x000A, 0x001A, 0x000C, 0x001C, 0x000E, 0x001E, 0x0001, 0x0011, 0x0003, 0x0013, 0x0005, 0x0015, 0x0007, 0x0017, 0x0009, 0x0019, 0x000B, 0x001B, 0x000D, 0x001D, 0x000F, 0x001F, 0xFFFF }, { 0x0F20, 0x0F30, 0x0E32, 0x0F22, 0x0E34, 0x0F24, 0x0D36, 0x0F26, 0x0C38, 0x0E28, 0x0B3A, 0x0E2A, 0x093C, 0x0E2C, 0x053E, 0x0D2E, 0x1E31, 0x1F21, 0x1D33, 0x1F23, 0x1C35, 0x1E25, 0x1A37, 0x1E27, 0x1839, 0x1D29, 0x163B, 0x1C2B, 0x133D, 0x1B2D, 0x093F, 0x1A2F, 0xFFFF }, }; // Really only [254][11]. static const uint16 g_color8_to_etc_block_config_1_to_254[254][12] = { { 0x021C, 0x0D0D, 0xFFFF }, { 0x0020, 0x0021, 0x0A0B, 0x061F, 0xFFFF }, { 0x0113, 0x0217, 0xFFFF }, { 0x0116, 0x031E, 0x0B0E, 0x0405, 0xFFFF }, { 0x0022, 0x0204, 0x050A, 0x0023, 0xFFFF }, { 0x0111, 0x0319, 0x0809, 0x170F, 0xFFFF }, { 0x0303, 0x0215, 0x0607, 0xFFFF }, { 0x0030, 0x0114, 0x0408, 0x0031, 0x0201, 0x051D, 0xFFFF }, { 0x0100, 0x0024, 0x0306, 0x0025, 0x041B, 0x0E0D, 0xFFFF }, { 0x021A, 0x0121, 0x0B0B, 0x071F, 0xFFFF }, { 0x0213, 0x0317, 0xFFFF }, { 0x0112, 0x0505, 0xFFFF }, { 0x0026, 0x070C, 0x0123, 0x0027, 0xFFFF }, { 0x0211, 0x0909, 0xFFFF }, { 0x0110, 0x0315, 0x0707, 0x0419, 0x180F, 0xFFFF }, { 0x0218, 0x0131, 0x0301, 0x0403, 0x061D, 0xFFFF }, { 0x0032, 0x0202, 0x0033, 0x0125, 0x051B, 0x0F0D, 0xFFFF }, { 0x0028, 0x031C, 0x0221, 0x0029, 0xFFFF }, { 0x0120, 0x0313, 0x0C0B, 0x081F, 0xFFFF }, { 0x0605, 0x0417, 0xFFFF }, { 0x0216, 0x041E, 0x0C0E, 0x0223, 0x0127, 0xFFFF }, { 0x0122, 0x0304, 0x060A, 0x0311, 0x0A09, 0xFFFF }, { 0x0519, 0x190F, 0xFFFF }, { 0x002A, 0x0231, 0x0503, 0x0415, 0x0807, 0x002B, 0x071D, 0xFFFF }, { 0x0130, 0x0214, 0x0508, 0x0401, 0x0133, 0x0225, 0x061B, 0xFFFF }, { 0x0200, 0x0124, 0x0406, 0x0321, 0x0129, 0x100D, 0xFFFF }, { 0x031A, 0x0D0B, 0x091F, 0xFFFF }, { 0x0413, 0x0705, 0x0517, 0xFFFF }, { 0x0212, 0x0034, 0x0323, 0x0035, 0x0227, 0xFFFF }, { 0x0126, 0x080C, 0x0B09, 0xFFFF }, { 0x0411, 0x0619, 0x1A0F, 0xFFFF }, { 0x0210, 0x0331, 0x0603, 0x0515, 0x0907, 0x012B, 0xFFFF }, { 0x0318, 0x002C, 0x0501, 0x0233, 0x0325, 0x071B, 0x002D, 0x081D, 0xFFFF }, { 0x0132, 0x0302, 0x0229, 0x110D, 0xFFFF }, { 0x0128, 0x041C, 0x0421, 0x0E0B, 0x0A1F, 0xFFFF }, { 0x0220, 0x0513, 0x0617, 0xFFFF }, { 0x0135, 0x0805, 0x0327, 0xFFFF }, { 0x0316, 0x051E, 0x0D0E, 0x0423, 0xFFFF }, { 0x0222, 0x0404, 0x070A, 0x0511, 0x0719, 0x0C09, 0x1B0F, 0xFFFF }, { 0x0703, 0x0615, 0x0A07, 0x022B, 0xFFFF }, { 0x012A, 0x0431, 0x0601, 0x0333, 0x012D, 0x091D, 0xFFFF }, { 0x0230, 0x0314, 0x0036, 0x0608, 0x0425, 0x0037, 0x0329, 0x081B, 0x120D, 0xFFFF }, { 0x0300, 0x0224, 0x0506, 0x0521, 0x0F0B, 0x0B1F, 0xFFFF }, { 0x041A, 0x0613, 0x0717, 0xFFFF }, { 0x0235, 0x0905, 0xFFFF }, { 0x0312, 0x0134, 0x0523, 0x0427, 0xFFFF }, { 0x0226, 0x090C, 0x002E, 0x0611, 0x0D09, 0x002F, 0xFFFF }, { 0x0715, 0x0B07, 0x0819, 0x032B, 0x1C0F, 0xFFFF }, { 0x0310, 0x0531, 0x0701, 0x0803, 0x022D, 0x0A1D, 0xFFFF }, { 0x0418, 0x012C, 0x0433, 0x0525, 0x0137, 0x091B, 0x130D, 0xFFFF }, { 0x0232, 0x0402, 0x0621, 0x0429, 0xFFFF }, { 0x0228, 0x051C, 0x0713, 0x100B, 0x0C1F, 0xFFFF }, { 0x0320, 0x0335, 0x0A05, 0x0817, 0xFFFF }, { 0x0623, 0x0527, 0xFFFF }, { 0x0416, 0x061E, 0x0E0E, 0x0711, 0x0E09, 0x012F, 0xFFFF }, { 0x0322, 0x0504, 0x080A, 0x0919, 0x1D0F, 0xFFFF }, { 0x0631, 0x0903, 0x0815, 0x0C07, 0x042B, 0x032D, 0x0B1D, 0xFFFF }, { 0x022A, 0x0801, 0x0533, 0x0625, 0x0237, 0x0A1B, 0xFFFF }, { 0x0330, 0x0414, 0x0136, 0x0708, 0x0721, 0x0529, 0x140D, 0xFFFF }, { 0x0400, 0x0324, 0x0606, 0x0038, 0x0039, 0x110B, 0x0D1F, 0xFFFF }, { 0x051A, 0x0813, 0x0B05, 0x0917, 0xFFFF }, { 0x0723, 0x0435, 0x0627, 0xFFFF }, { 0x0412, 0x0234, 0x0F09, 0x022F, 0xFFFF }, { 0x0326, 0x0A0C, 0x012E, 0x0811, 0x0A19, 0x1E0F, 0xFFFF }, { 0x0731, 0x0A03, 0x0915, 0x0D07, 0x052B, 0xFFFF }, { 0x0410, 0x0901, 0x0633, 0x0725, 0x0337, 0x0B1B, 0x042D, 0x0C1D, 0xFFFF }, { 0x0518, 0x022C, 0x0629, 0x150D, 0xFFFF }, { 0x0332, 0x0502, 0x0821, 0x0139, 0x120B, 0x0E1F, 0xFFFF }, { 0x0328, 0x061C, 0x0913, 0x0A17, 0xFFFF }, { 0x0420, 0x0535, 0x0C05, 0x0727, 0xFFFF }, { 0x0823, 0x032F, 0xFFFF }, { 0x0516, 0x071E, 0x0F0E, 0x0911, 0x0B19, 0x1009, 0x1F0F, 0xFFFF }, { 0x0422, 0x0604, 0x090A, 0x0B03, 0x0A15, 0x0E07, 0x062B, 0xFFFF }, { 0x0831, 0x0A01, 0x0733, 0x052D, 0x0D1D, 0xFFFF }, { 0x032A, 0x0825, 0x0437, 0x0729, 0x0C1B, 0x160D, 0xFFFF }, { 0x0430, 0x0514, 0x0236, 0x0808, 0x0921, 0x0239, 0x130B, 0x0F1F, 0xFFFF }, { 0x0500, 0x0424, 0x0706, 0x0138, 0x0A13, 0x0B17, 0xFFFF }, { 0x061A, 0x0635, 0x0D05, 0xFFFF }, { 0x0923, 0x0827, 0xFFFF }, { 0x0512, 0x0334, 0x003A, 0x0A11, 0x1109, 0x003B, 0x042F, 0xFFFF }, { 0x0426, 0x0B0C, 0x022E, 0x0B15, 0x0F07, 0x0C19, 0x072B, 0xFFFF }, { 0x0931, 0x0B01, 0x0C03, 0x062D, 0x0E1D, 0xFFFF }, { 0x0510, 0x0833, 0x0925, 0x0537, 0x0D1B, 0x170D, 0xFFFF }, { 0x0618, 0x032C, 0x0A21, 0x0339, 0x0829, 0xFFFF }, { 0x0432, 0x0602, 0x0B13, 0x140B, 0x101F, 0xFFFF }, { 0x0428, 0x071C, 0x0735, 0x0E05, 0x0C17, 0xFFFF }, { 0x0520, 0x0A23, 0x0927, 0xFFFF }, { 0x0B11, 0x1209, 0x013B, 0x052F, 0xFFFF }, { 0x0616, 0x081E, 0x0D19, 0xFFFF }, { 0x0522, 0x0704, 0x0A0A, 0x0A31, 0x0D03, 0x0C15, 0x1007, 0x082B, 0x072D, 0x0F1D, 0xFFFF }, { 0x0C01, 0x0933, 0x0A25, 0x0637, 0x0E1B, 0xFFFF }, { 0x042A, 0x0B21, 0x0929, 0x180D, 0xFFFF }, { 0x0530, 0x0614, 0x0336, 0x0908, 0x0439, 0x150B, 0x111F, 0xFFFF }, { 0x0600, 0x0524, 0x0806, 0x0238, 0x0C13, 0x0F05, 0x0D17, 0xFFFF }, { 0x071A, 0x0B23, 0x0835, 0x0A27, 0xFFFF }, { 0x1309, 0x023B, 0x062F, 0xFFFF }, { 0x0612, 0x0434, 0x013A, 0x0C11, 0x0E19, 0xFFFF }, { 0x0526, 0x0C0C, 0x032E, 0x0B31, 0x0E03, 0x0D15, 0x1107, 0x092B, 0xFFFF }, { 0x0D01, 0x0A33, 0x0B25, 0x0737, 0x0F1B, 0x082D, 0x101D, 0xFFFF }, { 0x0610, 0x0A29, 0x190D, 0xFFFF }, { 0x0718, 0x042C, 0x0C21, 0x0539, 0x160B, 0x121F, 0xFFFF }, { 0x0532, 0x0702, 0x0D13, 0x0E17, 0xFFFF }, { 0x0528, 0x081C, 0x0935, 0x1005, 0x0B27, 0xFFFF }, { 0x0620, 0x0C23, 0x033B, 0x072F, 0xFFFF }, { 0x0D11, 0x0F19, 0x1409, 0xFFFF }, { 0x0716, 0x003C, 0x091E, 0x0F03, 0x0E15, 0x1207, 0x0A2B, 0x003D, 0xFFFF }, { 0x0622, 0x0804, 0x0B0A, 0x0C31, 0x0E01, 0x0B33, 0x092D, 0x111D, 0xFFFF }, { 0x0C25, 0x0837, 0x0B29, 0x101B, 0x1A0D, 0xFFFF }, { 0x052A, 0x0D21, 0x0639, 0x170B, 0x131F, 0xFFFF }, { 0x0630, 0x0714, 0x0436, 0x0A08, 0x0E13, 0x0F17, 0xFFFF }, { 0x0700, 0x0624, 0x0906, 0x0338, 0x0A35, 0x1105, 0xFFFF }, { 0x081A, 0x0D23, 0x0C27, 0xFFFF }, { 0x0E11, 0x1509, 0x043B, 0x082F, 0xFFFF }, { 0x0712, 0x0534, 0x023A, 0x0F15, 0x1307, 0x1019, 0x0B2B, 0x013D, 0xFFFF }, { 0x0626, 0x0D0C, 0x042E, 0x0D31, 0x0F01, 0x1003, 0x0A2D, 0x121D, 0xFFFF }, { 0x0C33, 0x0D25, 0x0937, 0x111B, 0x1B0D, 0xFFFF }, { 0x0710, 0x0E21, 0x0739, 0x0C29, 0xFFFF }, { 0x0818, 0x052C, 0x0F13, 0x180B, 0x141F, 0xFFFF }, { 0x0632, 0x0802, 0x0B35, 0x1205, 0x1017, 0xFFFF }, { 0x0628, 0x091C, 0x0E23, 0x0D27, 0xFFFF }, { 0x0720, 0x0F11, 0x1609, 0x053B, 0x092F, 0xFFFF }, { 0x1119, 0x023D, 0xFFFF }, { 0x0816, 0x013C, 0x0A1E, 0x0E31, 0x1103, 0x1015, 0x1407, 0x0C2B, 0x0B2D, 0x131D, 0xFFFF }, { 0x0722, 0x0904, 0x0C0A, 0x1001, 0x0D33, 0x0E25, 0x0A37, 0x121B, 0xFFFF }, { 0x0F21, 0x0D29, 0x1C0D, 0xFFFF }, { 0x062A, 0x0839, 0x190B, 0x151F, 0xFFFF }, { 0x0730, 0x0814, 0x0536, 0x0B08, 0x1013, 0x1305, 0x1117, 0xFFFF }, { 0x0800, 0x0724, 0x0A06, 0x0438, 0x0F23, 0x0C35, 0x0E27, 0xFFFF }, { 0x091A, 0x1709, 0x063B, 0x0A2F, 0xFFFF }, { 0x1011, 0x1219, 0x033D, 0xFFFF }, { 0x0812, 0x0634, 0x033A, 0x0F31, 0x1203, 0x1115, 0x1507, 0x0D2B, 0xFFFF }, { 0x0726, 0x0E0C, 0x052E, 0x1101, 0x0E33, 0x0F25, 0x0B37, 0x131B, 0x0C2D, 0x141D, 0xFFFF }, { 0x0E29, 0x1D0D, 0xFFFF }, { 0x0810, 0x1021, 0x0939, 0x1A0B, 0x161F, 0xFFFF }, { 0x0918, 0x062C, 0x1113, 0x1217, 0xFFFF }, { 0x0732, 0x0902, 0x0D35, 0x1405, 0x0F27, 0xFFFF }, { 0x0728, 0x0A1C, 0x1023, 0x073B, 0x0B2F, 0xFFFF }, { 0x0820, 0x1111, 0x1319, 0x1809, 0xFFFF }, { 0x1303, 0x1215, 0x1607, 0x0E2B, 0x043D, 0xFFFF }, { 0x0916, 0x023C, 0x0B1E, 0x1031, 0x1201, 0x0F33, 0x0D2D, 0x151D, 0xFFFF }, { 0x0822, 0x0A04, 0x0D0A, 0x1025, 0x0C37, 0x0F29, 0x141B, 0x1E0D, 0xFFFF }, { 0x1121, 0x0A39, 0x1B0B, 0x171F, 0xFFFF }, { 0x072A, 0x1213, 0x1317, 0xFFFF }, { 0x0830, 0x0914, 0x0636, 0x0C08, 0x0E35, 0x1505, 0xFFFF }, { 0x0900, 0x0824, 0x0B06, 0x0538, 0x1123, 0x1027, 0xFFFF }, { 0x0A1A, 0x1211, 0x1909, 0x083B, 0x0C2F, 0xFFFF }, { 0x1315, 0x1707, 0x1419, 0x0F2B, 0x053D, 0xFFFF }, { 0x0912, 0x0734, 0x043A, 0x1131, 0x1301, 0x1403, 0x0E2D, 0x161D, 0xFFFF }, { 0x0826, 0x0F0C, 0x062E, 0x1033, 0x1125, 0x0D37, 0x151B, 0x1F0D, 0xFFFF }, { 0x1221, 0x0B39, 0x1029, 0xFFFF }, { 0x0910, 0x1313, 0x1C0B, 0x181F, 0xFFFF }, { 0x0A18, 0x072C, 0x0F35, 0x1605, 0x1417, 0xFFFF }, { 0x0832, 0x0A02, 0x1223, 0x1127, 0xFFFF }, { 0x0828, 0x0B1C, 0x1311, 0x1A09, 0x093B, 0x0D2F, 0xFFFF }, { 0x0920, 0x1519, 0x063D, 0xFFFF }, { 0x1231, 0x1503, 0x1415, 0x1807, 0x102B, 0x0F2D, 0x171D, 0xFFFF }, { 0x0A16, 0x033C, 0x0C1E, 0x1401, 0x1133, 0x1225, 0x0E37, 0x161B, 0xFFFF }, { 0x0922, 0x0B04, 0x0E0A, 0x1321, 0x1129, 0xFFFF }, { 0x0C39, 0x1D0B, 0x191F, 0xFFFF }, { 0x082A, 0x1413, 0x1705, 0x1517, 0xFFFF }, { 0x0930, 0x0A14, 0x0736, 0x0D08, 0x1323, 0x1035, 0x1227, 0xFFFF }, { 0x0A00, 0x0924, 0x0C06, 0x0638, 0x1B09, 0x0A3B, 0x0E2F, 0xFFFF }, { 0x0B1A, 0x1411, 0x1619, 0x073D, 0xFFFF }, { 0x1331, 0x1603, 0x1515, 0x1907, 0x112B, 0xFFFF }, { 0x0A12, 0x0834, 0x053A, 0x1501, 0x1233, 0x1325, 0x0F37, 0x171B, 0x102D, 0x181D, 0xFFFF }, { 0x0926, 0x072E, 0x1229, 0xFFFF }, { 0x1421, 0x0D39, 0x1E0B, 0x1A1F, 0xFFFF }, { 0x0A10, 0x1513, 0x1617, 0xFFFF }, { 0x0B18, 0x082C, 0x1135, 0x1805, 0x1327, 0xFFFF }, { 0x0932, 0x0B02, 0x1423, 0x0B3B, 0x0F2F, 0xFFFF }, { 0x0928, 0x0C1C, 0x1511, 0x1719, 0x1C09, 0xFFFF }, { 0x0A20, 0x1703, 0x1615, 0x1A07, 0x122B, 0x083D, 0xFFFF }, { 0x1431, 0x1601, 0x1333, 0x112D, 0x191D, 0xFFFF }, { 0x0B16, 0x043C, 0x0D1E, 0x1425, 0x1037, 0x1329, 0x181B, 0xFFFF }, { 0x0A22, 0x0C04, 0x0F0A, 0x1521, 0x0E39, 0x1F0B, 0x1B1F, 0xFFFF }, { 0x1613, 0x1717, 0xFFFF }, { 0x092A, 0x1235, 0x1905, 0xFFFF }, { 0x0A30, 0x0B14, 0x0836, 0x0E08, 0x1523, 0x1427, 0xFFFF }, { 0x0B00, 0x0A24, 0x0D06, 0x0738, 0x1611, 0x1D09, 0x0C3B, 0x102F, 0xFFFF }, { 0x0C1A, 0x1715, 0x1B07, 0x1819, 0x132B, 0x093D, 0xFFFF }, { 0x1531, 0x1701, 0x1803, 0x122D, 0x1A1D, 0xFFFF }, { 0x0B12, 0x0934, 0x063A, 0x1433, 0x1525, 0x1137, 0x191B, 0xFFFF }, { 0x0A26, 0x003E, 0x082E, 0x1621, 0x0F39, 0x1429, 0x003F, 0xFFFF }, { 0x1713, 0x1C1F, 0xFFFF }, { 0x0B10, 0x1335, 0x1A05, 0x1817, 0xFFFF }, { 0x0C18, 0x092C, 0x1623, 0x1527, 0xFFFF }, { 0x0A32, 0x0C02, 0x1711, 0x1E09, 0x0D3B, 0x112F, 0xFFFF }, { 0x0A28, 0x0D1C, 0x1919, 0x0A3D, 0xFFFF }, { 0x0B20, 0x1631, 0x1903, 0x1815, 0x1C07, 0x142B, 0x132D, 0x1B1D, 0xFFFF }, { 0x1801, 0x1533, 0x1625, 0x1237, 0x1A1B, 0xFFFF }, { 0x0C16, 0x053C, 0x0E1E, 0x1721, 0x1529, 0x013F, 0xFFFF }, { 0x0B22, 0x0D04, 0x1039, 0x1D1F, 0xFFFF }, { 0x1813, 0x1B05, 0x1917, 0xFFFF }, { 0x0A2A, 0x1723, 0x1435, 0x1627, 0xFFFF }, { 0x0B30, 0x0C14, 0x0936, 0x0F08, 0x1F09, 0x0E3B, 0x122F, 0xFFFF }, { 0x0C00, 0x0B24, 0x0E06, 0x0838, 0x1811, 0x1A19, 0x0B3D, 0xFFFF }, { 0x0D1A, 0x1731, 0x1A03, 0x1915, 0x1D07, 0x152B, 0xFFFF }, { 0x1901, 0x1633, 0x1725, 0x1337, 0x1B1B, 0x142D, 0x1C1D, 0xFFFF }, { 0x0C12, 0x0A34, 0x073A, 0x1629, 0x023F, 0xFFFF }, { 0x0B26, 0x013E, 0x092E, 0x1821, 0x1139, 0x1E1F, 0xFFFF }, { 0x1913, 0x1A17, 0xFFFF }, { 0x0C10, 0x1535, 0x1C05, 0x1727, 0xFFFF }, { 0x0D18, 0x0A2C, 0x1823, 0x0F3B, 0x132F, 0xFFFF }, { 0x0B32, 0x0D02, 0x1911, 0x1B19, 0xFFFF }, { 0x0B28, 0x0E1C, 0x1B03, 0x1A15, 0x1E07, 0x162B, 0x0C3D, 0xFFFF }, { 0x0C20, 0x1831, 0x1A01, 0x1733, 0x152D, 0x1D1D, 0xFFFF }, { 0x1825, 0x1437, 0x1729, 0x1C1B, 0x033F, 0xFFFF }, { 0x0D16, 0x063C, 0x0F1E, 0x1921, 0x1239, 0x1F1F, 0xFFFF }, { 0x0C22, 0x0E04, 0x1A13, 0x1B17, 0xFFFF }, { 0x1635, 0x1D05, 0xFFFF }, { 0x0B2A, 0x1923, 0x1827, 0xFFFF }, { 0x0C30, 0x0D14, 0x0A36, 0x1A11, 0x103B, 0x142F, 0xFFFF }, { 0x0D00, 0x0C24, 0x0F06, 0x0938, 0x1B15, 0x1F07, 0x1C19, 0x172B, 0x0D3D, 0xFFFF }, { 0x0E1A, 0x1931, 0x1B01, 0x1C03, 0x162D, 0x1E1D, 0xFFFF }, { 0x1833, 0x1925, 0x1537, 0x1D1B, 0xFFFF }, { 0x0D12, 0x0B34, 0x083A, 0x1A21, 0x1339, 0x1829, 0x043F, 0xFFFF }, { 0x0C26, 0x023E, 0x0A2E, 0x1B13, 0xFFFF }, { 0x1735, 0x1E05, 0x1C17, 0xFFFF }, { 0x0D10, 0x1A23, 0x1927, 0xFFFF }, { 0x0E18, 0x0B2C, 0x1B11, 0x113B, 0x152F, 0xFFFF }, { 0x0C32, 0x0E02, 0x1D19, 0x0E3D, 0xFFFF }, { 0x0C28, 0x0F1C, 0x1A31, 0x1D03, 0x1C15, 0x182B, 0x172D, 0x1F1D, 0xFFFF }, { 0x0D20, 0x1C01, 0x1933, 0x1A25, 0x1637, 0x1E1B, 0xFFFF }, { 0x1B21, 0x1929, 0x053F, 0xFFFF }, { 0x0E16, 0x073C, 0x1439, 0xFFFF }, { 0x0D22, 0x0F04, 0x1C13, 0x1F05, 0x1D17, 0xFFFF }, { 0x1B23, 0x1835, 0x1A27, 0xFFFF }, { 0x0C2A, 0x123B, 0x162F, 0xFFFF }, { 0x0D30, 0x0E14, 0x0B36, 0x1C11, 0x1E19, 0x0F3D, 0xFFFF }, { 0x0E00, 0x0D24, 0x0A38, 0x1B31, 0x1E03, 0x1D15, 0x192B, 0xFFFF }, { 0x0F1A, 0x1D01, 0x1A33, 0x1B25, 0x1737, 0x1F1B, 0x182D, 0xFFFF }, { 0x1A29, 0x063F, 0xFFFF }, { 0x0E12, 0x0C34, 0x093A, 0x1C21, 0x1539, 0xFFFF }, { 0x0D26, 0x033E, 0x0B2E, 0x1D13, 0x1E17, 0xFFFF }, { 0x1935, 0x1B27, 0xFFFF }, { 0x0E10, 0x1C23, 0x133B, 0x172F, 0xFFFF }, { 0x0F18, 0x0C2C, 0x1D11, 0x1F19, 0xFFFF }, { 0x0D32, 0x0F02, 0x1F03, 0x1E15, 0x1A2B, 0x103D, 0xFFFF }, { 0x0D28, 0x1C31, 0x1E01, 0x1B33, 0x192D, 0xFFFF }, { 0x0E20, 0x1C25, 0x1837, 0x1B29, 0x073F, 0xFFFF }, { 0x1D21, 0x1639, 0xFFFF }, { 0x0F16, 0x083C, 0x1E13, 0x1F17, 0xFFFF }, { 0x0E22, 0x1A35, 0xFFFF }, { 0x1D23, 0x1C27, 0xFFFF }, { 0x0D2A, 0x1E11, 0x143B, 0x182F, 0xFFFF }, { 0x0E30, 0x0F14, 0x0C36, 0x1F15, 0x1B2B, 0x113D, 0xFFFF }, { 0x0F00, 0x0E24, 0x0B38, 0x1D31, 0x1F01, 0x1A2D, 0xFFFF }, { 0x1C33, 0x1D25, 0x1937, 0xFFFF }, { 0x1E21, 0x1739, 0x1C29, 0x083F, 0xFFFF }, { 0x0F12, 0x0D34, 0x0A3A, 0x1F13, 0xFFFF }, { 0x0E26, 0x043E, 0x0C2E, 0x1B35, 0xFFFF }, { 0x1E23, 0x1D27, 0xFFFF }, { 0x0F10, 0x1F11, 0x153B, 0x192F, 0xFFFF }, { 0x0D2C, 0x123D, 0xFFFF }, }; uint16 etc1_block::pack_color5(const color_quad_u8& color, bool scaled, uint bias) { return pack_color5(color.r, color.g, color.b, scaled, bias); } uint16 etc1_block::pack_color5(uint r, uint g, uint b, bool scaled, uint bias) { if (scaled) { r = (r * 31U + bias) / 255U; g = (g * 31U + bias) / 255U; b = (b * 31U + bias) / 255U; } r = math::minimum(r, 31U); g = math::minimum(g, 31U); b = math::minimum(b, 31U); return static_cast(b | (g << 5U) | (r << 10U)); } color_quad_u8 etc1_block::unpack_color5(uint16 packed_color5, bool scaled, uint alpha) { uint b = packed_color5 & 31U; uint g = (packed_color5 >> 5U) & 31U; uint r = (packed_color5 >> 10U) & 31U; if (scaled) { b = (b << 3U) | (b >> 2U); g = (g << 3U) | (g >> 2U); r = (r << 3U) | (r >> 2U); } return color_quad_u8(cNoClamp, r, g, b, math::minimum(alpha, 255U)); } void etc1_block::unpack_color5(uint& r, uint& g, uint& b, uint16 packed_color5, bool scaled) { color_quad_u8 c(unpack_color5(packed_color5, scaled, 0)); r = c.r; g = c.g; b = c.b; } bool etc1_block::unpack_color5(color_quad_u8& result, uint16 packed_color5, uint16 packed_delta3, bool scaled, uint alpha) { color_quad_i16 dc(unpack_delta3(packed_delta3)); int b = (packed_color5 & 31U) + dc.b; int g = ((packed_color5 >> 5U) & 31U) + dc.g; int r = ((packed_color5 >> 10U) & 31U) + dc.r; bool success = true; if (static_cast(r | g | b) > 31U) { success = false; r = math::clamp(r, 0, 31); g = math::clamp(g, 0, 31); b = math::clamp(b, 0, 31); } if (scaled) { b = (b << 3U) | (b >> 2U); g = (g << 3U) | (g >> 2U); r = (r << 3U) | (r >> 2U); } result.set_noclamp_rgba(r, g, b, math::minimum(alpha, 255U)); return success; } bool etc1_block::unpack_color5(uint& r, uint& g, uint& b, uint16 packed_color5, uint16 packed_delta3, bool scaled, uint alpha) { color_quad_u8 result; const bool success = unpack_color5(result, packed_color5, packed_delta3, scaled, alpha); r = result.r; g = result.g; b = result.b; return success; } uint16 etc1_block::pack_delta3(const color_quad_i16& color) { return pack_delta3(color.r, color.g, color.b); } uint16 etc1_block::pack_delta3(int r, int g, int b) { CRNLIB_ASSERT((r >= cETC1ColorDeltaMin) && (r <= cETC1ColorDeltaMax)); CRNLIB_ASSERT((g >= cETC1ColorDeltaMin) && (g <= cETC1ColorDeltaMax)); CRNLIB_ASSERT((b >= cETC1ColorDeltaMin) && (b <= cETC1ColorDeltaMax)); if (r < 0) r += 8; if (g < 0) g += 8; if (b < 0) b += 8; return static_cast(b | (g << 3) | (r << 6)); } color_quad_i16 etc1_block::unpack_delta3(uint16 packed_delta3) { int r = (packed_delta3 >> 6) & 7; int g = (packed_delta3 >> 3) & 7; int b = packed_delta3 & 7; if (r >= 4) r -= 8; if (g >= 4) g -= 8; if (b >= 4) b -= 8; return color_quad_i16(r, g, b, 0); } void etc1_block::unpack_delta3(int& r, int& g, int& b, uint16 packed_delta3) { r = (packed_delta3 >> 6) & 7; g = (packed_delta3 >> 3) & 7; b = packed_delta3 & 7; if (r >= 4) r -= 8; if (g >= 4) g -= 8; if (b >= 4) b -= 8; } uint16 etc1_block::pack_color4(const color_quad_u8& color, bool scaled, uint bias) { return pack_color4(color.r, color.g, color.b, scaled, bias); } uint16 etc1_block::pack_color4(uint r, uint g, uint b, bool scaled, uint bias) { if (scaled) { r = (r * 15U + bias) / 255U; g = (g * 15U + bias) / 255U; b = (b * 15U + bias) / 255U; } r = math::minimum(r, 15U); g = math::minimum(g, 15U); b = math::minimum(b, 15U); return static_cast(b | (g << 4U) | (r << 8U)); } color_quad_u8 etc1_block::unpack_color4(uint16 packed_color4, bool scaled, uint alpha) { uint b = packed_color4 & 15U; uint g = (packed_color4 >> 4U) & 15U; uint r = (packed_color4 >> 8U) & 15U; if (scaled) { b = (b << 4U) | b; g = (g << 4U) | g; r = (r << 4U) | r; } return color_quad_u8(cNoClamp, r, g, b, math::minimum(alpha, 255U)); } void etc1_block::unpack_color4(uint& r, uint& g, uint& b, uint16 packed_color4, bool scaled) { color_quad_u8 c(unpack_color4(packed_color4, scaled, 0)); r = c.r; g = c.g; b = c.b; } void etc1_block::get_diff_subblock_colors(color_quad_u8* pDst, uint16 packed_color5, uint table_idx) { CRNLIB_ASSERT(table_idx < cETC1IntenModifierValues); const int *pInten_modifer_table = &g_etc1_inten_tables[table_idx][0]; uint r, g, b; unpack_color5(r, g, b, packed_color5, true); const int ir = static_cast(r), ig = static_cast(g), ib = static_cast(b); const int y0 = pInten_modifer_table[0]; pDst[0].set(ir + y0, ig + y0, ib + y0); const int y1 = pInten_modifer_table[1]; pDst[1].set(ir + y1, ig + y1, ib + y1); const int y2 = pInten_modifer_table[2]; pDst[2].set(ir + y2, ig + y2, ib + y2); const int y3 = pInten_modifer_table[3]; pDst[3].set(ir + y3, ig + y3, ib + y3); } bool etc1_block::get_diff_subblock_colors(color_quad_u8* pDst, uint16 packed_color5, uint16 packed_delta3, uint table_idx) { CRNLIB_ASSERT(table_idx < cETC1IntenModifierValues); const int *pInten_modifer_table = &g_etc1_inten_tables[table_idx][0]; uint r, g, b; bool success = unpack_color5(r, g, b, packed_color5, packed_delta3, true); const int ir = static_cast(r), ig = static_cast(g), ib = static_cast(b); const int y0 = pInten_modifer_table[0]; pDst[0].set(ir + y0, ig + y0, ib + y0); const int y1 = pInten_modifer_table[1]; pDst[1].set(ir + y1, ig + y1, ib + y1); const int y2 = pInten_modifer_table[2]; pDst[2].set(ir + y2, ig + y2, ib + y2); const int y3 = pInten_modifer_table[3]; pDst[3].set(ir + y3, ig + y3, ib + y3); return success; } void etc1_block::get_abs_subblock_colors(color_quad_u8* pDst, uint16 packed_color4, uint table_idx) { CRNLIB_ASSERT(table_idx < cETC1IntenModifierValues); const int *pInten_modifer_table = &g_etc1_inten_tables[table_idx][0]; uint r, g, b; unpack_color4(r, g, b, packed_color4, true); const int ir = static_cast(r), ig = static_cast(g), ib = static_cast(b); const int y0 = pInten_modifer_table[0]; pDst[0].set(ir + y0, ig + y0, ib + y0); const int y1 = pInten_modifer_table[1]; pDst[1].set(ir + y1, ig + y1, ib + y1); const int y2 = pInten_modifer_table[2]; pDst[2].set(ir + y2, ig + y2, ib + y2); const int y3 = pInten_modifer_table[3]; pDst[3].set(ir + y3, ig + y3, ib + y3); } bool unpack_etc1(const etc1_block& block, color_quad_u8 *pDst, bool preserve_alpha) { const bool diff_flag = block.get_diff_bit(); const bool flip_flag = block.get_flip_bit(); const uint table_index0 = block.get_inten_table(0); const uint table_index1 = block.get_inten_table(1); color_quad_u8 subblock_colors0[4]; color_quad_u8 subblock_colors1[4]; bool success = true; if (diff_flag) { const uint16 base_color5 = block.get_base5_color(); const uint16 delta_color3 = block.get_delta3_color(); etc1_block::get_diff_subblock_colors(subblock_colors0, base_color5, table_index0); if (!etc1_block::get_diff_subblock_colors(subblock_colors1, base_color5, delta_color3, table_index1)) success = false; } else { const uint16 base_color4_0 = block.get_base4_color(0); etc1_block::get_abs_subblock_colors(subblock_colors0, base_color4_0, table_index0); const uint16 base_color4_1 = block.get_base4_color(1); etc1_block::get_abs_subblock_colors(subblock_colors1, base_color4_1, table_index1); } if (preserve_alpha) { if (flip_flag) { for (uint y = 0; y < 2; y++) { pDst[0].set_rgb(subblock_colors0[block.get_selector(0, y)]); pDst[1].set_rgb(subblock_colors0[block.get_selector(1, y)]); pDst[2].set_rgb(subblock_colors0[block.get_selector(2, y)]); pDst[3].set_rgb(subblock_colors0[block.get_selector(3, y)]); pDst += 4; } for (uint y = 2; y < 4; y++) { pDst[0].set_rgb(subblock_colors1[block.get_selector(0, y)]); pDst[1].set_rgb(subblock_colors1[block.get_selector(1, y)]); pDst[2].set_rgb(subblock_colors1[block.get_selector(2, y)]); pDst[3].set_rgb(subblock_colors1[block.get_selector(3, y)]); pDst += 4; } } else { for (uint y = 0; y < 4; y++) { pDst[0].set_rgb(subblock_colors0[block.get_selector(0, y)]); pDst[1].set_rgb(subblock_colors0[block.get_selector(1, y)]); pDst[2].set_rgb(subblock_colors1[block.get_selector(2, y)]); pDst[3].set_rgb(subblock_colors1[block.get_selector(3, y)]); pDst += 4; } } } else { if (flip_flag) { // 0000 // 0000 // 1111 // 1111 for (uint y = 0; y < 2; y++) { pDst[0] = subblock_colors0[block.get_selector(0, y)]; pDst[1] = subblock_colors0[block.get_selector(1, y)]; pDst[2] = subblock_colors0[block.get_selector(2, y)]; pDst[3] = subblock_colors0[block.get_selector(3, y)]; pDst += 4; } for (uint y = 2; y < 4; y++) { pDst[0] = subblock_colors1[block.get_selector(0, y)]; pDst[1] = subblock_colors1[block.get_selector(1, y)]; pDst[2] = subblock_colors1[block.get_selector(2, y)]; pDst[3] = subblock_colors1[block.get_selector(3, y)]; pDst += 4; } } else { // 0011 // 0011 // 0011 // 0011 for (uint y = 0; y < 4; y++) { pDst[0] = subblock_colors0[block.get_selector(0, y)]; pDst[1] = subblock_colors0[block.get_selector(1, y)]; pDst[2] = subblock_colors1[block.get_selector(2, y)]; pDst[3] = subblock_colors1[block.get_selector(3, y)]; pDst += 4; } } } return success; } bool etc1_optimizer::compute() { const uint n = m_pParams->m_num_src_pixels; const int scan_delta_size = m_pParams->m_scan_delta_size; // Scan through a subset of the 3D lattice centered around the avg block color trying each 3D (555 or 444) lattice point as a potential block color. // Each time a better solution is found try to refine the current solution's block color based of the current selectors and intensity table index. for (int zdi = 0; zdi < scan_delta_size; zdi++) { const int zd = m_pParams->m_pScan_deltas[zdi]; const int mbb = m_bb + zd; if (mbb < 0) continue; else if (mbb > m_limit) break; for (int ydi = 0; ydi < scan_delta_size; ydi++) { const int yd = m_pParams->m_pScan_deltas[ydi]; const int mbg = m_bg + yd; if (mbg < 0) continue; else if (mbg > m_limit) break; for (int xdi = 0; xdi < scan_delta_size; xdi++) { const int xd = m_pParams->m_pScan_deltas[xdi]; const int mbr = m_br + xd; if (mbr < 0) continue; else if (mbr > m_limit) break; etc1_solution_coordinates coords(mbr, mbg, mbb, 0, m_pParams->m_use_color4); if (m_pParams->m_quality == cCRNETCQualitySlow) { if (!evaluate_solution(coords, m_trial_solution, &m_best_solution)) continue; } else { if (!evaluate_solution_fast(coords, m_trial_solution, &m_best_solution)) continue; } // Now we have the input block, the avg. color of the input pixels, a set of trial selector indices, and the block color+intensity index. // Now, for each component, attempt to refine the current solution by solving a simple linear equation. For example, for 4 colors: // The goal is: // pixel0 - (block_color+inten_table[selector0]) + pixel1 - (block_color+inten_table[selector1]) + pixel2 - (block_color+inten_table[selector2]) + pixel3 - (block_color+inten_table[selector3]) = 0 // Rearranging this: // (pixel0 + pixel1 + pixel2 + pixel3) - (block_color+inten_table[selector0]) - (block_color+inten_table[selector1]) - (block_color+inten_table[selector2]) - (block_color+inten_table[selector3]) = 0 // (pixel0 + pixel1 + pixel2 + pixel3) - block_color - inten_table[selector0] - block_color-inten_table[selector1] - block_color-inten_table[selector2] - block_color-inten_table[selector3] = 0 // (pixel0 + pixel1 + pixel2 + pixel3) - 4*block_color - inten_table[selector0] - inten_table[selector1] - inten_table[selector2] - inten_table[selector3] = 0 // (pixel0 + pixel1 + pixel2 + pixel3) - 4*block_color - (inten_table[selector0] + inten_table[selector1] + inten_table[selector2] + inten_table[selector3]) = 0 // (pixel0 + pixel1 + pixel2 + pixel3)/4 - block_color - (inten_table[selector0] + inten_table[selector1] + inten_table[selector2] + inten_table[selector3])/4 = 0 // block_color = (pixel0 + pixel1 + pixel2 + pixel3)/4 - (inten_table[selector0] + inten_table[selector1] + inten_table[selector2] + inten_table[selector3])/4 // So what this means: // optimal_block_color = avg_input - avg_inten_delta // So the optimal block color can be computed by taking the average block color and subtracting the current average of the intensity delta. // Unfortunately, optimal_block_color must then be quantized to 555 or 444 so it's not always possible to improve matters using this formula. // Also, the above formula is for unclamped intensity deltas. The actual implementation takes into account clamping. const uint max_refinement_trials = (m_pParams->m_quality == cCRNETCQualityFast) ? 2 : (((xd | yd | zd) == 0) ? 4 : 2); for (uint refinement_trial = 0; refinement_trial < max_refinement_trials; refinement_trial++) { const uint8* pSelectors = m_best_solution.m_selectors.get_ptr(); const int* pInten_table = g_etc1_inten_tables[m_best_solution.m_coords.m_inten_table]; int delta_sum_r = 0, delta_sum_g = 0, delta_sum_b = 0; const color_quad_u8 base_color(m_best_solution.m_coords.get_scaled_color()); for (uint r = 0; r < n; r++) { const uint s = *pSelectors++; const int yd = pInten_table[s]; // Compute actual delta being applied to each pixel, taking into account clamping. delta_sum_r += math::clamp(base_color.r + yd, 0, 255) - base_color.r; delta_sum_g += math::clamp(base_color.g + yd, 0, 255) - base_color.g; delta_sum_b += math::clamp(base_color.b + yd, 0, 255) - base_color.b; } if ((!delta_sum_r) && (!delta_sum_g) && (!delta_sum_b)) break; const float avg_delta_r_f = static_cast(delta_sum_r) / n; const float avg_delta_g_f = static_cast(delta_sum_g) / n; const float avg_delta_b_f = static_cast(delta_sum_b) / n; const int br1 = math::clamp(static_cast((m_avg_color[0] - avg_delta_r_f) * m_limit / 255.0f + .5f), 0, m_limit); const int bg1 = math::clamp(static_cast((m_avg_color[1] - avg_delta_g_f) * m_limit / 255.0f + .5f), 0, m_limit); const int bb1 = math::clamp(static_cast((m_avg_color[2] - avg_delta_b_f) * m_limit / 255.0f + .5f), 0, m_limit); bool skip = false; if ((mbr == br1) && (mbg == bg1) && (mbb == bb1)) skip = true; else if ((br1 == m_best_solution.m_coords.m_unscaled_color.r) && (bg1 == m_best_solution.m_coords.m_unscaled_color.g) && (bb1 == m_best_solution.m_coords.m_unscaled_color.b)) skip = true; else if ((m_br == br1) && (m_bg == bg1) && (m_bb == bb1)) skip = true; if (skip) break; etc1_solution_coordinates coords1(br1, bg1, bb1, 0, m_pParams->m_use_color4); if (m_pParams->m_quality == cCRNETCQualitySlow) { if (!evaluate_solution(coords1, m_trial_solution, &m_best_solution)) break; } else { if (!evaluate_solution_fast(coords1, m_trial_solution, &m_best_solution)) break; } } // refinement_trial } // xdi } // ydi } // zdi if (!m_best_solution.m_valid) { m_pResult->m_error = cUINT32_MAX; return false; } const uint8* pSelectors = m_best_solution.m_selectors.get_ptr(); #ifdef CRNLIB_BUILD_DEBUG { color_quad_u8 block_colors[4]; m_best_solution.m_coords.get_block_colors(block_colors); const color_quad_u8* pSrc_pixels = m_pParams->m_pSrc_pixels; uint64 actual_error = 0; for (uint i = 0; i < n; i++) actual_error += color::elucidian_distance(pSrc_pixels[i], block_colors[pSelectors[i]], false); CRNLIB_ASSERT(actual_error == m_best_solution.m_error); } #endif m_pResult->m_error = m_best_solution.m_error; m_pResult->m_block_color_unscaled = m_best_solution.m_coords.m_unscaled_color; m_pResult->m_block_color4 = m_best_solution.m_coords.m_color4; m_pResult->m_block_inten_table = m_best_solution.m_coords.m_inten_table; memcpy(m_pResult->m_pSelectors, pSelectors, n); m_pResult->m_n = n; return true; } void etc1_optimizer::init(const params& params, results& result) { m_pParams = ¶ms; m_pResult = &result; const uint n = m_pParams->m_num_src_pixels; m_selectors.resize(n); m_best_selectors.resize(n); m_temp_selectors.resize(n); m_trial_solution.m_selectors.resize(n); m_best_solution.m_selectors.resize(n); m_limit = m_pParams->m_use_color4 ? 15 : 31; vec3F avg_color(0.0f); m_luma.resize(n); m_sorted_luma[0].resize(n); m_sorted_luma[1].resize(n); for (uint i = 0; i < n; i++) { const color_quad_u8& c = m_pParams->m_pSrc_pixels[i]; const vec3F fc(c.r, c.g, c.b); avg_color += fc; m_luma[i] = static_cast(c.r + c.g + c.b); m_sorted_luma[0][i] = i; } avg_color /= static_cast(n); m_avg_color = avg_color; m_br = math::clamp(static_cast(m_avg_color[0] * m_limit / 255.0f + .5f), 0, m_limit); m_bg = math::clamp(static_cast(m_avg_color[1] * m_limit / 255.0f + .5f), 0, m_limit); m_bb = math::clamp(static_cast(m_avg_color[2] * m_limit / 255.0f + .5f), 0, m_limit); if (m_pParams->m_quality <= cCRNETCQualityMedium) { m_pSorted_luma_indices = indirect_radix_sort(n, m_sorted_luma[0].get_ptr(), m_sorted_luma[1].get_ptr(), m_luma.get_ptr(), 0, sizeof(m_luma[0]), false); m_pSorted_luma = m_sorted_luma[0].get_ptr(); if (m_pSorted_luma_indices == m_sorted_luma[0].get_ptr()) m_pSorted_luma = m_sorted_luma[1].get_ptr(); for (uint i = 0; i < n; i++) m_pSorted_luma[i] = m_luma[m_pSorted_luma_indices[i]]; } m_best_solution.m_coords.clear(); m_best_solution.m_valid = false; m_best_solution.m_error = cUINT64_MAX; } bool etc1_optimizer::evaluate_solution(const etc1_solution_coordinates& coords, potential_solution& trial_solution, potential_solution* pBest_solution) { trial_solution.m_valid = false; if (m_pParams->m_constrain_against_base_color5) { const int dr = coords.m_unscaled_color.r - m_pParams->m_base_color5.r; const int dg = coords.m_unscaled_color.g - m_pParams->m_base_color5.g; const int db = coords.m_unscaled_color.b - m_pParams->m_base_color5.b; if ((math::minimum(dr, dg, db) < cETC1ColorDeltaMin) || (math::maximum(dr, dg, db) > cETC1ColorDeltaMax)) return false; } const color_quad_u8 base_color(coords.get_scaled_color()); const uint n = m_pParams->m_num_src_pixels; CRNLIB_ASSERT(trial_solution.m_selectors.size() == n); trial_solution.m_error = cUINT64_MAX; for (uint inten_table = 0; inten_table < cETC1IntenModifierValues; inten_table++) { const int* pInten_table = g_etc1_inten_tables[inten_table]; color_quad_u8 block_colors[4]; for (uint s = 0; s < 4; s++) { const int yd = pInten_table[s]; block_colors[s].set(base_color.r + yd, base_color.g + yd, base_color.b + yd, 0); } uint64 total_error = 0; const color_quad_u8* pSrc_pixels = m_pParams->m_pSrc_pixels; for (uint c = 0; c < n; c++) { const color_quad_u8& src_pixel = *pSrc_pixels++; uint best_selector_index = 0; uint best_error = math::square(src_pixel.r - block_colors[0].r) + math::square(src_pixel.g - block_colors[0].g) + math::square(src_pixel.b - block_colors[0].b); uint trial_error = math::square(src_pixel.r - block_colors[1].r) + math::square(src_pixel.g - block_colors[1].g) + math::square(src_pixel.b - block_colors[1].b); if (trial_error < best_error) { best_error = trial_error; best_selector_index = 1; } trial_error = math::square(src_pixel.r - block_colors[2].r) + math::square(src_pixel.g - block_colors[2].g) + math::square(src_pixel.b - block_colors[2].b); if (trial_error < best_error) { best_error = trial_error; best_selector_index = 2; } trial_error = math::square(src_pixel.r - block_colors[3].r) + math::square(src_pixel.g - block_colors[3].g) + math::square(src_pixel.b - block_colors[3].b); if (trial_error < best_error) { best_error = trial_error; best_selector_index = 3; } m_temp_selectors[c] = static_cast(best_selector_index); total_error += best_error; if (total_error >= trial_solution.m_error) break; } if (total_error < trial_solution.m_error) { trial_solution.m_error = total_error; trial_solution.m_coords.m_inten_table = inten_table; trial_solution.m_selectors.swap(m_temp_selectors); trial_solution.m_valid = true; } } trial_solution.m_coords.m_unscaled_color = coords.m_unscaled_color; trial_solution.m_coords.m_color4 = m_pParams->m_use_color4; bool success = false; if (pBest_solution) { if (trial_solution.m_error < pBest_solution->m_error) { *pBest_solution = trial_solution; success = true; } } return success; } bool etc1_optimizer::evaluate_solution_fast(const etc1_solution_coordinates& coords, potential_solution& trial_solution, potential_solution* pBest_solution) { if (m_pParams->m_constrain_against_base_color5) { const int dr = coords.m_unscaled_color.r - m_pParams->m_base_color5.r; const int dg = coords.m_unscaled_color.g - m_pParams->m_base_color5.g; const int db = coords.m_unscaled_color.b - m_pParams->m_base_color5.b; if ((math::minimum(dr, dg, db) < cETC1ColorDeltaMin) || (math::maximum(dr, dg, db) > cETC1ColorDeltaMax)) { trial_solution.m_valid = false; return false; } } const color_quad_u8 base_color(coords.get_scaled_color()); const uint n = m_pParams->m_num_src_pixels; CRNLIB_ASSERT(trial_solution.m_selectors.size() == n); trial_solution.m_error = cUINT64_MAX; for (int inten_table = cETC1IntenModifierValues - 1; inten_table >= 0; --inten_table) { const int* pInten_table = g_etc1_inten_tables[inten_table]; uint block_inten[4]; color_quad_u8 block_colors[4]; for (uint s = 0; s < 4; s++) { const int yd = pInten_table[s]; color_quad_u8 block_color(base_color.r + yd, base_color.g + yd, base_color.b + yd, 0); block_colors[s] = block_color; block_inten[s] = block_color.r + block_color.g + block_color.b; } // evaluate_solution_fast() enforces/assumesd a total ordering of the input colors along the intensity (1,1,1) axis to more quickly classify the inputs to selectors. // The inputs colors have been presorted along the projection onto this axis, and ETC1 block colors are always ordered along the intensity axis, so this classification is fast. // 0 1 2 3 // 01 12 23 const uint block_inten_midpoints[3] = { block_inten[0] + block_inten[1], block_inten[1] + block_inten[2], block_inten[2] + block_inten[3] }; uint64 total_error = 0; const color_quad_u8* pSrc_pixels = m_pParams->m_pSrc_pixels; if ((m_pSorted_luma[n - 1] * 2) < block_inten_midpoints[0]) { if (block_inten[0] > m_pSorted_luma[n - 1]) { const uint min_error = labs(block_inten[0] - m_pSorted_luma[n - 1]); if (min_error >= trial_solution.m_error) continue; } memset(&m_temp_selectors[0], 0, n); for (uint c = 0; c < n; c++) total_error += color::elucidian_distance(block_colors[0], pSrc_pixels[c], false); } else if ((m_pSorted_luma[0] * 2) >= block_inten_midpoints[2]) { if (m_pSorted_luma[0] > block_inten[3]) { const uint min_error = labs(m_pSorted_luma[0] - block_inten[3]); if (min_error >= trial_solution.m_error) continue; } memset(&m_temp_selectors[0], 3, n); for (uint c = 0; c < n; c++) total_error += color::elucidian_distance(block_colors[3], pSrc_pixels[c], false); } else { uint cur_selector = 0, c; for (c = 0; c < n; c++) { const uint y = m_pSorted_luma[c]; while ((y * 2) >= block_inten_midpoints[cur_selector]) if (++cur_selector > 2) goto done; const uint sorted_pixel_index = m_pSorted_luma_indices[c]; m_temp_selectors[sorted_pixel_index] = static_cast(cur_selector); total_error += color::elucidian_distance(block_colors[cur_selector], pSrc_pixels[sorted_pixel_index], false); } done: while (c < n) { const uint sorted_pixel_index = m_pSorted_luma_indices[c]; m_temp_selectors[sorted_pixel_index] = 3; total_error += color::elucidian_distance(block_colors[3], pSrc_pixels[sorted_pixel_index], false); ++c; } } if (total_error < trial_solution.m_error) { trial_solution.m_error = total_error; trial_solution.m_coords.m_inten_table = inten_table; trial_solution.m_selectors.swap(m_temp_selectors); trial_solution.m_valid = true; if (!total_error) break; } } trial_solution.m_coords.m_unscaled_color = coords.m_unscaled_color; trial_solution.m_coords.m_color4 = m_pParams->m_use_color4; bool success = false; if (pBest_solution) { if (trial_solution.m_error < pBest_solution->m_error) { *pBest_solution = trial_solution; success = true; } } return success; } // Dither function from RYG's public domain real-time DXT1 compressor, modified for 555. static void DitherBlock(color_quad_u8 *dest, const color_quad_u8 *block) { int err[8],*ep1 = err,*ep2 = err+4; uint8 *quant = ryg_dxt::QuantRBTab+8; // process channels seperately for(int ch=0;ch<3;ch++) { uint8 *bp = (uint8 *) block; uint8 *dp = (uint8 *) dest; bp += ch; dp += ch; memset(err,0,sizeof(err)); for(int y=0;y<4;y++) { // pixel 0 dp[ 0] = quant[bp[ 0] + ((3*ep2[1] + 5*ep2[0]) >> 4)]; ep1[0] = bp[ 0] - dp[ 0]; // pixel 1 dp[ 4] = quant[bp[ 4] + ((7*ep1[0] + 3*ep2[2] + 5*ep2[1] + ep2[0]) >> 4)]; ep1[1] = bp[ 4] - dp[ 4]; // pixel 2 dp[ 8] = quant[bp[ 8] + ((7*ep1[1] + 3*ep2[3] + 5*ep2[2] + ep2[1]) >> 4)]; ep1[2] = bp[ 8] - dp[ 8]; // pixel 3 dp[12] = quant[bp[12] + ((7*ep1[2] + 5*ep2[3] + ep2[2]) >> 4)]; ep1[3] = bp[12] - dp[12]; // advance to next line std::swap(ep1,ep2); bp += 16; dp += 16; } } } static uint etc1_decode_value(uint diff, uint inten, uint selector, uint packed_c) { const uint limit = diff ? 32 : 16; limit; CRNLIB_ASSERT((diff < 2) && (inten < 8) && (selector < 4) && (packed_c < limit)); int c; if (diff) c = (packed_c >> 2) | (packed_c << 3); else c = packed_c | (packed_c << 4); c += g_etc1_inten_tables[inten][selector]; c = math::clamp(c, 0, 255); return c; } void pack_etc1_block_init() { for (uint diff = 0; diff < 2; diff++) { const uint limit = diff ? 32 : 16; for (uint inten = 0; inten < 8; inten++) { for (uint selector = 0; selector < 4; selector++) { const uint inverse_table_index = diff + (inten << 1) + (selector << 4); for (uint color = 0; color < 256; color++) { uint best_error = cUINT32_MAX, best_packed_c = 0; for (uint packed_c = 0; packed_c < limit; packed_c++) { int v = etc1_decode_value(diff, inten, selector, packed_c); uint err = labs(v - color); if (err < best_error) { best_error = err; best_packed_c = packed_c; if (!best_error) break; } } CRNLIB_ASSERT(best_error <= 255); g_etc1_inverse_lookup[inverse_table_index][color] = static_cast(best_packed_c | (best_error << 8)); } } } } } // Packs solid color blocks efficiently using a set of small precomputed tables. // For random 888 inputs, MSE results are better than Erricson's ETC1 packer in "slow" mode ~9.5% of the time, is slightly worse only ~.01% of the time, and is equal the rest of the time. static uint64 pack_etc1_block_solid_color(etc1_block& block, const uint8* pColor, crn_etc1_pack_params& pack_params, pack_etc1_block_context& context) { CRNLIB_ASSERT(g_etc1_inverse_lookup[0][255]); context, pack_params; static uint s_next_comp[4] = { 1, 2, 0, 1 }; uint best_error = cUINT32_MAX, best_i = 0; int best_x = 0, best_packed_c1 = 0, best_packed_c2 = 0; // For each possible 8-bit value, there is a precomputed list of diff/inten/selector configurations that allow that 8-bit value to be encoded with no error. for (uint i = 0; i < 3; i++) { const uint c1 = pColor[s_next_comp[i]], c2 = pColor[s_next_comp[i + 1]]; const int delta_range = 1; for (int delta = -delta_range; delta <= delta_range; delta++) { const int c_plus_delta = math::clamp(pColor[i] + delta, 0, 255); const uint16* pTable; if (!c_plus_delta) pTable = g_color8_to_etc_block_config_0_255[0]; else if (c_plus_delta == 255) pTable = g_color8_to_etc_block_config_0_255[1]; else pTable = g_color8_to_etc_block_config_1_to_254[c_plus_delta - 1]; do { const uint x = *pTable++; #ifdef CRNLIB_BUILD_DEBUG const uint diff = x & 1; const uint inten = (x >> 1) & 7; const uint selector = (x >> 4) & 3; const uint p0 = (x >> 8) & 255; CRNLIB_ASSERT(etc1_decode_value(diff, inten, selector, p0) == (uint)c_plus_delta); #endif const uint16* pInverse_table = g_etc1_inverse_lookup[x & 0xFF]; uint16 p1 = pInverse_table[c1]; uint16 p2 = pInverse_table[c2]; const uint trial_error = math::square(c_plus_delta - pColor[i]) + math::square(p1 >> 8) + math::square(p2 >> 8); if (trial_error < best_error) { best_error = trial_error; best_x = x; best_packed_c1 = p1 & 0xFF; best_packed_c2 = p2 & 0xFF; best_i = i; if (!best_error) goto found_perfect_match; } } while (*pTable != 0xFFFF); } } found_perfect_match: const uint diff = best_x & 1; const uint inten = (best_x >> 1) & 7; block.m_bytes[3] = static_cast(((inten | (inten << 3)) << 2) | (diff << 1)); const uint etc1_selector = g_selector_index_to_etc1[(best_x >> 4) & 3]; *reinterpret_cast(&block.m_bytes[4]) = (etc1_selector & 2) ? 0xFFFF : 0; *reinterpret_cast(&block.m_bytes[6]) = (etc1_selector & 1) ? 0xFFFF : 0; const uint best_packed_c0 = (best_x >> 8) & 255; if (diff) { block.m_bytes[best_i] = static_cast(best_packed_c0 << 3); block.m_bytes[s_next_comp[best_i]] = static_cast(best_packed_c1 << 3); block.m_bytes[s_next_comp[best_i+1]] = static_cast(best_packed_c2 << 3); } else { block.m_bytes[best_i] = static_cast(best_packed_c0 | (best_packed_c0 << 4)); block.m_bytes[s_next_comp[best_i]] = static_cast(best_packed_c1 | (best_packed_c1 << 4)); block.m_bytes[s_next_comp[best_i+1]] = static_cast(best_packed_c2 | (best_packed_c2 << 4)); } return best_error; } static uint pack_etc1_block_solid_color_constrained( etc1_optimizer::results& results, uint num_colors, const uint8 *pColor, crn_etc1_pack_params& pack_params, pack_etc1_block_context& context, bool use_diff, const color_quad_u8* pBase_color5_unscaled) { CRNLIB_ASSERT(g_etc1_inverse_lookup[0][255]); context, pack_params; static uint s_next_comp[4] = { 1, 2, 0, 1 }; uint best_error = cUINT32_MAX, best_i = 0; int best_x = 0, best_packed_c1 = 0, best_packed_c2 = 0; // For each possible 8-bit value, there is a precomputed list of diff/inten/selector configurations that allow that 8-bit value to be encoded with no error. for (uint i = 0; i < 3; i++) { const uint c1 = pColor[s_next_comp[i]], c2 = pColor[s_next_comp[i + 1]]; const int delta_range = 1; for (int delta = -delta_range; delta <= delta_range; delta++) { const int c_plus_delta = math::clamp(pColor[i] + delta, 0, 255); const uint16* pTable; if (!c_plus_delta) pTable = g_color8_to_etc_block_config_0_255[0]; else if (c_plus_delta == 255) pTable = g_color8_to_etc_block_config_0_255[1]; else pTable = g_color8_to_etc_block_config_1_to_254[c_plus_delta - 1]; do { const uint x = *pTable++; const uint diff = x & 1; if (static_cast(use_diff) != diff) { if (*pTable == 0xFFFF) break; continue; } if ((diff) && (pBase_color5_unscaled)) { const int p0 = (x >> 8) & 255; int delta = p0 - static_cast(pBase_color5_unscaled->c[i]); if ((delta < cETC1ColorDeltaMin) || (delta > cETC1ColorDeltaMax)) { if (*pTable == 0xFFFF) break; continue; } } #ifdef CRNLIB_BUILD_DEBUG { const uint inten = (x >> 1) & 7; const uint selector = (x >> 4) & 3; const uint p0 = (x >> 8) & 255; CRNLIB_ASSERT(etc1_decode_value(diff, inten, selector, p0) == (uint)c_plus_delta); } #endif const uint16* pInverse_table = g_etc1_inverse_lookup[x & 0xFF]; uint16 p1 = pInverse_table[c1]; uint16 p2 = pInverse_table[c2]; if ((diff) && (pBase_color5_unscaled)) { int delta1 = (p1 & 0xFF) - static_cast(pBase_color5_unscaled->c[s_next_comp[i]]); int delta2 = (p2 & 0xFF) - static_cast(pBase_color5_unscaled->c[s_next_comp[i + 1]]); if ((delta1 < cETC1ColorDeltaMin) || (delta1 > cETC1ColorDeltaMax) || (delta2 < cETC1ColorDeltaMin) || (delta2 > cETC1ColorDeltaMax)) { if (*pTable == 0xFFFF) break; continue; } } const uint trial_error = math::square(c_plus_delta - pColor[i]) + math::square(p1 >> 8) + math::square(p2 >> 8); if (trial_error < best_error) { best_error = trial_error; best_x = x; best_packed_c1 = p1 & 0xFF; best_packed_c2 = p2 & 0xFF; best_i = i; if (!best_error) goto found_perfect_match; } } while (*pTable != 0xFFFF); } } found_perfect_match: if (best_error == cUINT32_MAX) return best_error; best_error *= num_colors; results.m_n = num_colors; results.m_block_color4 = !(best_x & 1); results.m_block_inten_table = (best_x >> 1) & 7; memset(results.m_pSelectors, (best_x >> 4) & 3, num_colors); const uint best_packed_c0 = (best_x >> 8) & 255; results.m_block_color_unscaled[best_i] = static_cast(best_packed_c0); results.m_block_color_unscaled[s_next_comp[best_i]] = static_cast(best_packed_c1); results.m_block_color_unscaled[s_next_comp[best_i + 1]] = static_cast(best_packed_c2); results.m_error = best_error; return best_error; } uint64 pack_etc1_block(etc1_block& dst_block, const color_quad_u8* pSrc_pixels, crn_etc1_pack_params& pack_params, pack_etc1_block_context& context) { color_quad_u8 src_pixel0(pSrc_pixels[0]); int r; for (r = 15; r >= 1; --r) if ((pSrc_pixels[r].r != src_pixel0.r) || (pSrc_pixels[r].g != src_pixel0.g) || (pSrc_pixels[r].b != src_pixel0.b)) break; if (!r) return 16 * pack_etc1_block_solid_color(dst_block, &pSrc_pixels[0].r, pack_params, context); color_quad_u8 dithered_pixels[16]; if (pack_params.m_dithering) { DitherBlock(dithered_pixels, pSrc_pixels); pSrc_pixels = dithered_pixels; } uint64 best_error = cUINT64_MAX; uint best_flip = false, best_use_color4 = false; uint8 best_selectors[2][8]; etc1_optimizer::results best_results[2]; for (uint i = 0; i < 2; i++) { best_results[i].m_n = 8; best_results[i].m_pSelectors = best_selectors[i]; } uint8 selectors[3][8]; etc1_optimizer::results results[3]; for (uint i = 0; i < 3; i++) { results[i].m_n = 8; results[i].m_pSelectors = selectors[i]; } color_quad_u8 subblock_pixels[8]; etc1_optimizer::params params(pack_params); params.m_num_src_pixels = 8; params.m_pSrc_pixels = subblock_pixels; for (uint flip = 0; flip < 2; flip++) { for (uint use_color4 = 0; use_color4 < 2; use_color4++) { uint64 trial_error = 0; uint subblock; for (subblock = 0; subblock < 2; subblock++) { if (flip) memcpy(subblock_pixels, pSrc_pixels + subblock * 8, sizeof(color_quad_u8) * 8); else { const color_quad_u8* pSrc_col = pSrc_pixels + subblock * 2; subblock_pixels[0] = pSrc_col[0]; subblock_pixels[1] = pSrc_col[4]; subblock_pixels[2] = pSrc_col[8]; subblock_pixels[3] = pSrc_col[12]; subblock_pixels[4] = pSrc_col[1]; subblock_pixels[5] = pSrc_col[5]; subblock_pixels[6] = pSrc_col[9]; subblock_pixels[7] = pSrc_col[13]; } results[2].m_error = cUINT64_MAX; if ((params.m_quality >= cCRNETCQualityMedium) && ((subblock) || (use_color4))) { color_quad_u8 subblock_pixel0(subblock_pixels[0]); for (r = 7; r >= 1; --r) if ((subblock_pixels[r].r != subblock_pixel0.r) || (subblock_pixels[r].g != subblock_pixel0.g) || (subblock_pixels[r].b != subblock_pixel0.b)) break; if (!r) { pack_etc1_block_solid_color_constrained(results[2], 8, &subblock_pixel0.r, pack_params, context, !use_color4, (subblock && !use_color4) ? &results[0].m_block_color_unscaled : NULL); } } params.m_use_color4 = (use_color4 != 0); params.m_constrain_against_base_color5 = false; if ((!use_color4) && (subblock)) { params.m_constrain_against_base_color5 = true; params.m_base_color5 = results[0].m_block_color_unscaled; } if (params.m_quality == cCRNETCQualitySlow) { static const int s_scan_delta_0_to_4[] = { -4, -3, -2, -1, 0, 1, 2, 3, 4 }; params.m_scan_delta_size = CRNLIB_ARRAY_SIZE(s_scan_delta_0_to_4); params.m_pScan_deltas = s_scan_delta_0_to_4; } else if (params.m_quality == cCRNETCQualityMedium) { static const int s_scan_delta_0_to_1[] = { -1, 0, 1 }; params.m_scan_delta_size = CRNLIB_ARRAY_SIZE(s_scan_delta_0_to_1); params.m_pScan_deltas = s_scan_delta_0_to_1; } else { static const int s_scan_delta_0[] = { 0 }; params.m_scan_delta_size = CRNLIB_ARRAY_SIZE(s_scan_delta_0); params.m_pScan_deltas = s_scan_delta_0; } context.m_optimizer.init(params, results[subblock]); if (!context.m_optimizer.compute()) break; // Fairly arbitrary/unrefined thresholds that control how far away to scan for potentially better solutions. const uint refinement_error_thresh0 = 3000; const uint refinement_error_thresh1 = 6000; if ((params.m_quality >= cCRNETCQualityMedium) && (results[subblock].m_error > refinement_error_thresh0)) { if (params.m_quality == cCRNETCQualityMedium) { static const int s_scan_delta_2_to_3[] = { -3, -2, 2, 3 }; params.m_scan_delta_size = CRNLIB_ARRAY_SIZE(s_scan_delta_2_to_3); params.m_pScan_deltas = s_scan_delta_2_to_3; } else { static const int s_scan_delta_5_to_5[] = { -5, 5 }; static const int s_scan_delta_5_to_8[] = { -8, -7, -6, -5, 5, 6, 7, 8 }; if (results[subblock].m_error > refinement_error_thresh1) { params.m_scan_delta_size = CRNLIB_ARRAY_SIZE(s_scan_delta_5_to_8); params.m_pScan_deltas = s_scan_delta_5_to_8; } else { params.m_scan_delta_size = CRNLIB_ARRAY_SIZE(s_scan_delta_5_to_5); params.m_pScan_deltas = s_scan_delta_5_to_5; } } if (!context.m_optimizer.compute()) break; } if (results[2].m_error < results[subblock].m_error) results[subblock] = results[2]; trial_error += results[subblock].m_error; if (trial_error >= best_error) break; } if (subblock < 2) continue; best_error = trial_error; best_results[0] = results[0]; best_results[1] = results[1]; best_flip = flip; best_use_color4 = use_color4; } // use_color4 } // flip int dr = best_results[1].m_block_color_unscaled.r - best_results[0].m_block_color_unscaled.r; int dg = best_results[1].m_block_color_unscaled.g - best_results[0].m_block_color_unscaled.g; int db = best_results[1].m_block_color_unscaled.b - best_results[0].m_block_color_unscaled.b; if (!best_use_color4) { if ((math::minimum(dr, dg, db) < cETC1ColorDeltaMin) || (math::maximum(dr, dg, db) > cETC1ColorDeltaMax)) { // Shouldn't ever happen CRNLIB_VERIFY(0); } } if (best_use_color4) { dst_block.m_bytes[0] = static_cast(best_results[1].m_block_color_unscaled.r | (best_results[0].m_block_color_unscaled.r << 4)); dst_block.m_bytes[1] = static_cast(best_results[1].m_block_color_unscaled.g | (best_results[0].m_block_color_unscaled.g << 4)); dst_block.m_bytes[2] = static_cast(best_results[1].m_block_color_unscaled.b | (best_results[0].m_block_color_unscaled.b << 4)); } else { if (dr < 0) dr += 8; if (dg < 0) dg += 8; if (db < 0) db += 8; dst_block.m_bytes[0] = static_cast((best_results[0].m_block_color_unscaled.r << 3) | dr); dst_block.m_bytes[1] = static_cast((best_results[0].m_block_color_unscaled.g << 3) | dg); dst_block.m_bytes[2] = static_cast((best_results[0].m_block_color_unscaled.b << 3) | db); } dst_block.m_bytes[3] = static_cast( (best_results[1].m_block_inten_table << 2) | (best_results[0].m_block_inten_table << 5) | ((~best_use_color4 & 1) << 1) | best_flip ); uint selector0 = 0, selector1 = 0; if (best_flip) { // flipped: // { 0, 0 }, { 1, 0 }, { 2, 0 }, { 3, 0 }, // { 0, 1 }, { 1, 1 }, { 2, 1 }, { 3, 1 } // // { 0, 2 }, { 1, 2 }, { 2, 2 }, { 3, 2 }, // { 0, 3 }, { 1, 3 }, { 2, 3 }, { 3, 3 } const uint8* pSelectors0 = best_results[0].m_pSelectors; const uint8* pSelectors1 = best_results[1].m_pSelectors; for (int x = 3; x >= 0; --x) { uint b; b = g_selector_index_to_etc1[pSelectors1[4 + x]]; selector0 = (selector0 << 1) | (b & 1); selector1 = (selector1 << 1) | (b >> 1); b = g_selector_index_to_etc1[pSelectors1[x]]; selector0 = (selector0 << 1) | (b & 1); selector1 = (selector1 << 1) | (b >> 1); b = g_selector_index_to_etc1[pSelectors0[4 + x]]; selector0 = (selector0 << 1) | (b & 1); selector1 = (selector1 << 1) | (b >> 1); b = g_selector_index_to_etc1[pSelectors0[x]]; selector0 = (selector0 << 1) | (b & 1); selector1 = (selector1 << 1) | (b >> 1); } } else { // non-flipped: // { 0, 0 }, { 0, 1 }, { 0, 2 }, { 0, 3 }, // { 1, 0 }, { 1, 1 }, { 1, 2 }, { 1, 3 } // // { 2, 0 }, { 2, 1 }, { 2, 2 }, { 2, 3 }, // { 3, 0 }, { 3, 1 }, { 3, 2 }, { 3, 3 } for (int subblock = 1; subblock >= 0; --subblock) { const uint8* pSelectors = best_results[subblock].m_pSelectors + 4; for (uint i = 0; i < 2; i++) { uint b; b = g_selector_index_to_etc1[pSelectors[3]]; selector0 = (selector0 << 1) | (b & 1); selector1 = (selector1 << 1) | (b >> 1); b = g_selector_index_to_etc1[pSelectors[2]]; selector0 = (selector0 << 1) | (b & 1); selector1 = (selector1 << 1) | (b >> 1); b = g_selector_index_to_etc1[pSelectors[1]]; selector0 = (selector0 << 1) | (b & 1); selector1 = (selector1 << 1) | (b >> 1); b = g_selector_index_to_etc1[pSelectors[0]]; selector0 = (selector0 << 1) | (b & 1);selector1 = (selector1 << 1) | (b >> 1); pSelectors -= 4; } } } dst_block.m_bytes[4] = static_cast(selector1 >> 8); dst_block.m_bytes[5] = static_cast(selector1 & 0xFF); dst_block.m_bytes[6] = static_cast(selector0 >> 8); dst_block.m_bytes[7] = static_cast(selector0 & 0xFF); return best_error; } } // namespace crnlib