1/* Decomposition of Unicode characters. 2 Copyright (C) 2009-2010 Free Software Foundation, Inc. 3 Written by Bruno Haible <bruno@clisp.org>, 2009. 4 5 This program is free software: you can redistribute it and/or modify it 6 under the terms of the GNU Lesser General Public License as published 7 by the Free Software Foundation; either version 3 of the License, or 8 (at your option) any later version. 9 10 This program is distributed in the hope that it will be useful, 11 but WITHOUT ANY WARRANTY; without even the implied warranty of 12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 13 Lesser General Public License for more details. 14 15 You should have received a copy of the GNU Lesser General Public License 16 along with this program. If not, see <http://www.gnu.org/licenses/>. */ 17 18#include <config.h> 19 20/* Specification. */ 21#include "uninorm.h" 22 23#include "decomposition-table.h" 24 25int 26uc_decomposition (ucs4_t uc, int *decomp_tag, ucs4_t *decomposition) 27{ 28 if (uc >= 0xAC00 && uc < 0xD7A4) 29 { 30 /* Hangul syllable. See Unicode standard, chapter 3, section 31 "Hangul Syllable Decomposition", See also the clarification at 32 <http://www.unicode.org/versions/Unicode5.1.0/>, section 33 "Clarification of Hangul Jamo Handling". */ 34 unsigned int t; 35 36 uc -= 0xAC00; 37 t = uc % 28; 38 39 *decomp_tag = UC_DECOMP_CANONICAL; 40 if (t == 0) 41 { 42 unsigned int v, l; 43 44 uc = uc / 28; 45 v = uc % 21; 46 l = uc / 21; 47 48 decomposition[0] = 0x1100 + l; 49 decomposition[1] = 0x1161 + v; 50 return 2; 51 } 52 else 53 { 54#if 1 /* Return the pairwise decomposition, not the full decomposition. */ 55 decomposition[0] = 0xAC00 + uc - t; /* = 0xAC00 + (l * 21 + v) * 28; */ 56 decomposition[1] = 0x11A7 + t; 57 return 2; 58#else 59 unsigned int v, l; 60 61 uc = uc / 28; 62 v = uc % 21; 63 l = uc / 21; 64 65 decomposition[0] = 0x1100 + l; 66 decomposition[1] = 0x1161 + v; 67 decomposition[2] = 0x11A7 + t; 68 return 3; 69#endif 70 } 71 } 72 else if (uc < 0x110000) 73 { 74 unsigned short entry = decomp_index (uc); 75 if (entry != (unsigned short)(-1)) 76 { 77 const unsigned char *p; 78 unsigned int element; 79 unsigned int length; 80 81 p = &gl_uninorm_decomp_chars_table[3 * (entry & 0x7FFF)]; 82 element = (p[0] << 16) | (p[1] << 8) | p[2]; 83 /* The first element has 5 bits for the decomposition type. */ 84 *decomp_tag = (element >> 18) & 0x1f; 85 length = 1; 86 for (;;) 87 { 88 /* Every element has an 18 bits wide Unicode code point. */ 89 *decomposition = element & 0x3ffff; 90 /* Bit 23 tells whether there are more elements, */ 91 if ((element & (1 << 23)) == 0) 92 break; 93 p += 3; 94 element = (p[0] << 16) | (p[1] << 8) | p[2]; 95 decomposition++; 96 length++; 97 } 98 return length; 99 } 100 } 101 return -1; 102} 103