| /* Decomposition of Unicode characters. |
| Copyright (C) 2009-2020 Free Software Foundation, Inc. |
| Written by Bruno Haible <bruno@clisp.org>, 2009. |
| |
| This program is free software: you can redistribute it and/or modify it |
| under the terms of the GNU Lesser General Public License as published |
| by the Free Software Foundation; either version 3 of the License, or |
| (at your option) any later version. |
| |
| This program is distributed in the hope that it will be useful, |
| but WITHOUT ANY WARRANTY; without even the implied warranty of |
| MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| Lesser General Public License for more details. |
| |
| You should have received a copy of the GNU Lesser General Public License |
| along with this program. If not, see <https://www.gnu.org/licenses/>. */ |
| |
| #include <config.h> |
| |
| /* Specification. */ |
| #include "uninorm.h" |
| |
| #include "uninorm/decomposition-table.h" |
| |
| int |
| uc_decomposition (ucs4_t uc, int *decomp_tag, ucs4_t *decomposition) |
| { |
| if (uc >= 0xAC00 && uc < 0xD7A4) |
| { |
| /* Hangul syllable. See Unicode standard, chapter 3, section |
| "Hangul Syllable Decomposition", See also the clarification at |
| <https://www.unicode.org/versions/Unicode5.1.0/>, section |
| "Clarification of Hangul Jamo Handling". */ |
| unsigned int t; |
| |
| uc -= 0xAC00; |
| t = uc % 28; |
| |
| *decomp_tag = UC_DECOMP_CANONICAL; |
| if (t == 0) |
| { |
| unsigned int v, l; |
| |
| uc = uc / 28; |
| v = uc % 21; |
| l = uc / 21; |
| |
| decomposition[0] = 0x1100 + l; |
| decomposition[1] = 0x1161 + v; |
| return 2; |
| } |
| else |
| { |
| #if 1 /* Return the pairwise decomposition, not the full decomposition. */ |
| decomposition[0] = 0xAC00 + uc - t; /* = 0xAC00 + (l * 21 + v) * 28; */ |
| decomposition[1] = 0x11A7 + t; |
| return 2; |
| #else |
| unsigned int v, l; |
| |
| uc = uc / 28; |
| v = uc % 21; |
| l = uc / 21; |
| |
| decomposition[0] = 0x1100 + l; |
| decomposition[1] = 0x1161 + v; |
| decomposition[2] = 0x11A7 + t; |
| return 3; |
| #endif |
| } |
| } |
| else if (uc < 0x110000) |
| { |
| unsigned short entry = decomp_index (uc); |
| if (entry != (unsigned short)(-1)) |
| { |
| const unsigned char *p; |
| unsigned int element; |
| unsigned int length; |
| |
| p = &gl_uninorm_decomp_chars_table[3 * (entry & 0x7FFF)]; |
| element = (p[0] << 16) | (p[1] << 8) | p[2]; |
| /* The first element has 5 bits for the decomposition type. */ |
| *decomp_tag = (element >> 18) & 0x1f; |
| length = 1; |
| for (;;) |
| { |
| /* Every element has an 18 bits wide Unicode code point. */ |
| *decomposition = element & 0x3ffff; |
| /* Bit 23 tells whether there are more elements, */ |
| if ((element & (1 << 23)) == 0) |
| break; |
| p += 3; |
| element = (p[0] << 16) | (p[1] << 8) | p[2]; |
| decomposition++; |
| length++; |
| } |
| return length; |
| } |
| } |
| return -1; |
| } |