1/* 2 * Copyright (C) 1999-2001 Free Software Foundation, Inc. 3 * This file is part of the GNU LIBICONV Library. 4 * 5 * The GNU LIBICONV Library is free software; you can redistribute it 6 * and/or modify it under the terms of the GNU Library General Public 7 * License as published by the Free Software Foundation; either version 2 8 * of the License, or (at your option) any later version. 9 * 10 * The GNU LIBICONV Library is distributed in the hope that it will be 11 * useful, but WITHOUT ANY WARRANTY; without even the implied warranty of 12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 13 * Library General Public License for more details. 14 * 15 * You should have received a copy of the GNU Library General Public 16 * License along with the GNU LIBICONV Library; see the file COPYING.LIB. 17 * If not, write to the Free Software Foundation, Inc., 51 Franklin Street, 18 * Fifth Floor, Boston, MA 02110-1301, USA. 19 */ 20 21/* 22 * JOHAB 23 */ 24 25/* 26 Conversion between JOHAB codes (s1,s2) and KSX1001 codes (c1,c2): 27 Example. (s1,s2) = 0xD931, (c1,c2) = 0x2121. 28 (s1,s2) = 0xDEF1, (c1,c2) = 0x2C71. 29 (s1,s2) = 0xE031, (c1,c2) = 0x4A21. 30 (s1,s2) = 0xF9FE, (c1,c2) = 0x7D7E. 31 0xD9 <= s1 <= 0xDE || 0xE0 <= s1 <= 0xF9, 32 0x31 <= s2 <= 0x7E || 0x91 <= s2 <= 0xFE, 33 0x21 <= c1 <= 0x2C || 0x4A <= c1 <= 0x7D, 34 0x21 <= c2 <= 0x7E. 35 Invariant: 36 94*(s1 < 0xE0 ? 2*s1-0x1B2 : 2*s1-0x197) + (s2 < 0x91 ? s2-0x31 : s2-0x43) 37 = 94*(c1-0x21)+(c2-0x21) 38 Conversion (s1,s2) -> (c1,c2): 39 t1 := (s1 < 0xE0 ? 2*s1-0x1B2 : 2*s1-0x197) 40 t2 := (s2 < 0x91 ? s2-0x31 : s2-0x43) 41 c1 := t1 + (t2 < 0x5E ? 0 : 1) + 0x21 42 c2 := (t2 < 0x5E ? t2 : t2-0x5E) + 0x21 43 Conversion (c1,c2) -> (s1,s2): 44 t := (c1 < 0x4A ? (c1-0x21+0x1B2) : (c1-0x21+0x197)) 45 s1 := t >> 1 46 t2 := (t & 1) * 0x5E + (c2 - 0x21) 47 s2 := (t2 < 0x4E ? t2+0x31 : t2+0x43) 48 */ 49 50static int 51johab_mbtowc (conv_t conv, ucs4_t *pwc, const unsigned char *s, size_t n) 52{ 53 unsigned char c = *s; 54 if (c < 0x80) { 55 if (c == 0x5c) 56 *pwc = (ucs4_t) 0x20a9; 57 else 58 *pwc = (ucs4_t) c; 59 return 1; 60 } else if (c < 0xd8) { 61 return johab_hangul_mbtowc(conv,pwc,s,n); 62 } else { 63 unsigned char s1, s2; 64 s1 = c; 65 if ((s1 >= 0xd9 && s1 <= 0xde) || (s1 >= 0xe0 && s1 <= 0xf9)) { 66 if (n < 2) 67 return RET_TOOFEW(0); 68 s2 = s[1]; 69 if ((s2 >= 0x31 && s2 <= 0x7e) || (s2 >= 0x91 && s2 <= 0xfe)) { 70 /* In KSC 5601, the region s1 = 0xDA, 0xA1 <= s2 <= 0xD3 contains 71 the 51 Jamo (Hangul letters). But in the Johab encoding, they 72 have been moved to the Hangul section, see johab_hangul_page31. */ 73 if (!(s1 == 0xda && (s2 >= 0xa1 && s2 <= 0xd3))) { 74 unsigned char t1 = (s1 < 0xe0 ? 2*(s1-0xd9) : 2*s1-0x197); 75 unsigned char t2 = (s2 < 0x91 ? s2-0x31 : s2-0x43); 76 unsigned char buf[2]; 77 buf[0] = t1 + (t2 < 0x5e ? 0 : 1) + 0x21; 78 buf[1] = (t2 < 0x5e ? t2 : t2-0x5e) + 0x21; 79 return ksc5601_mbtowc(conv,pwc,buf,2); 80 } 81 } 82 } 83 return RET_ILSEQ; 84 } 85} 86 87static int 88johab_wctomb (conv_t conv, unsigned char *r, ucs4_t wc, size_t n) 89{ 90 unsigned char buf[2]; 91 int ret; 92 93 /* Try ASCII variation. */ 94 if (wc < 0x0080 && wc != 0x005c) { 95 *r = wc; 96 return 1; 97 } 98 if (wc == 0x20a9) { 99 *r = 0x5c; 100 return 1; 101 } 102 103 /* Try JOHAB Hangul table before KSC5601 table, because the KSC5601 table 104 contains some (2350 out of 11172) Hangul syllables (rows 0x30XX..0x48XX), 105 and we want the search to return the JOHAB Hangul table entry. */ 106 107 /* Try JOHAB Hangul. */ 108 ret = johab_hangul_wctomb(conv,buf,wc,2); 109 if (ret != RET_ILUNI) { 110 if (ret != 2) abort(); 111 if (n < 2) 112 return RET_TOOSMALL; 113 r[0] = buf[0]; 114 r[1] = buf[1]; 115 return 2; 116 } 117 118 /* Try KSC5601. */ 119 ret = ksc5601_wctomb(conv,buf,wc,2); 120 if (ret != RET_ILUNI) { 121 unsigned char c1, c2; 122 if (ret != 2) abort(); 123 if (n < 2) 124 return RET_TOOSMALL; 125 c1 = buf[0]; 126 c2 = buf[1]; 127 if (((c1 >= 0x21 && c1 <= 0x2c) || (c1 >= 0x4a && c1 <= 0x7d)) 128 && (c2 >= 0x21 && c2 <= 0x7e)) { 129 unsigned int t = (c1 < 0x4A ? (c1-0x21+0x1B2) : (c1-0x21+0x197)); 130 unsigned char t2 = ((t & 1) ? 0x5e : 0) + (c2 - 0x21); 131 r[0] = t >> 1; 132 r[1] = (t2 < 0x4e ? t2+0x31 : t2+0x43); 133 return 2; 134 } 135 } 136 137 return RET_ILUNI; 138} 139