1 /* 2 * Copyright (C) 1999-2001, 2007 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 50 static int 51 johab_mbtowc (conv_t conv, ucs4_t *pwc, const unsigned char *s, int 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, now KS X 1001, the region s1 = 0xDA, 0xA1 <= s2 <= 0xD3 71 contains the 51 Jamo (Hangul letters). But in the Johab encoding, 72 they have been moved to the Hangul section, see 73 johab_hangul_page31. */ 74 if (!(s1 == 0xda && (s2 >= 0xa1 && s2 <= 0xd3))) { 75 unsigned char t1 = (s1 < 0xe0 ? 2*(s1-0xd9) : 2*s1-0x197); 76 unsigned char t2 = (s2 < 0x91 ? s2-0x31 : s2-0x43); 77 unsigned char buf[2]; 78 buf[0] = t1 + (t2 < 0x5e ? 0 : 1) + 0x21; 79 buf[1] = (t2 < 0x5e ? t2 : t2-0x5e) + 0x21; 80 return ksc5601_mbtowc(conv,pwc,buf,2); 81 } 82 } 83 } 84 return RET_ILSEQ; 85 } 86 } 87 88 static int 89 johab_wctomb (conv_t conv, unsigned char *r, ucs4_t wc, int n) 90 { 91 unsigned char buf[2]; 92 int ret; 93 94 /* Try ASCII variation. */ 95 if (wc < 0x0080 && wc != 0x005c) { 96 *r = wc; 97 return 1; 98 } 99 if (wc == 0x20a9) { 100 *r = 0x5c; 101 return 1; 102 } 103 104 /* Try JOHAB Hangul table before KSC5601 table, because the KSC5601 table 105 contains some (2350 out of 11172) Hangul syllables (rows 0x30XX..0x48XX), 106 and we want the search to return the JOHAB Hangul table entry. */ 107 108 /* Try JOHAB Hangul. */ 109 ret = johab_hangul_wctomb(conv,buf,wc,2); 110 if (ret != RET_ILUNI) { 111 if (ret != 2) abort(); 112 if (n < 2) 113 return RET_TOOSMALL; 114 r[0] = buf[0]; 115 r[1] = buf[1]; 116 return 2; 117 } 118 119 /* Try KSC5601, now KS X 1001. */ 120 ret = ksc5601_wctomb(conv,buf,wc,2); 121 if (ret != RET_ILUNI) { 122 unsigned char c1, c2; 123 if (ret != 2) abort(); 124 if (n < 2) 125 return RET_TOOSMALL; 126 c1 = buf[0]; 127 c2 = buf[1]; 128 if (((c1 >= 0x21 && c1 <= 0x2c) || (c1 >= 0x4a && c1 <= 0x7d)) 129 && (c2 >= 0x21 && c2 <= 0x7e)) { 130 unsigned int t = (c1 < 0x4A ? (c1-0x21+0x1B2) : (c1-0x21+0x197)); 131 unsigned char t2 = ((t & 1) ? 0x5e : 0) + (c2 - 0x21); 132 r[0] = t >> 1; 133 r[1] = (t2 < 0x4e ? t2+0x31 : t2+0x43); 134 return 2; 135 } 136 } 137 138 return RET_ILUNI; 139 } 140