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 Hangul
23: *
24: * Ken Lunde writes in his "CJKV Information Processing" book, p. 114:
25: * "Hangul can be composed of two or three jamo (some jamo are considered
26: * compound). Johab uses 19 initial jamo (consonants), 21 medial jamo (vowels)
27: * and 27 final jamo (consonants; 28 when you include the "fill" character
28: * for Hangul containing only two jamo). Multiplying these numbers results in
29: * 11172."
30: *
31: * Structure of the Johab encoding (see p. 181-184):
32: * bit 15 = 1
33: * bit 14..10 = initial jamo, only 19+1 out of 32 possible values are used
34: * bit 9..5 = medial jamo, only 21+1 out of 32 possible values are used
35: * bit 4..0 = final jamo, only 27+1 out of 32 possible values are used
36: *
37: * Structure of the Unicode encoding:
38: * grep '^0x\([8-C]...\|D[0-7]..\)' unicode.org-mappings/EASTASIA/KSC/JOHAB.TXT
39: * You see that all characters there are marked "HANGUL LETTER" or "HANGUL
40: * SYLLABLE". If you eliminate the "HANGUL LETTER"s, the table is sorted
41: * in ascending order according to Johab encoding and according to the Unicode
42: * encoding. Now look a little more carefully, and you see that the following
43: * formula holds:
44: * unicode == 0xAC00
45: * + 21 * 28 * (jamo_initial_index[(johab >> 10) & 31] - 1)
46: * + 28 * (jamo_medial_index[(johab >> 5) & 31] - 1)
47: * + jamo_final_index[johab & 31]
48: * where the index tables are defined as below.
49: */
50:
51: /* Tables mapping 5-bit groups to jamo letters. */
52: /* Note that Jamo XX = UHC 0xA4A0+XX = Unicode 0x3130+XX */
53: #define NONE 0xfd
54: #define FILL 0xff
55: static const unsigned char jamo_initial[32] = {
56: NONE, FILL, 0x01, 0x02, 0x04, 0x07, 0x08, 0x09,
57: 0x11, 0x12, 0x13, 0x15, 0x16, 0x17, 0x18, 0x19,
58: 0x1a, 0x1b, 0x1c, 0x1d, 0x1e, NONE, NONE, NONE,
59: NONE, NONE, NONE, NONE, NONE, NONE, NONE, NONE,
60: };
61: static const unsigned char jamo_medial[32] = {
62: NONE, NONE, FILL, 0x1f, 0x20, 0x21, 0x22, 0x23,
63: NONE, NONE, 0x24, 0x25, 0x26, 0x27, 0x28, 0x29,
64: NONE, NONE, 0x2a, 0x2b, 0x2c, 0x2d, 0x2e, 0x2f,
65: NONE, NONE, 0x30, 0x31, 0x32, 0x33, NONE, NONE,
66: };
67: static const unsigned char jamo_final[32] = {
68: NONE, FILL, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06,
69: 0x07, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f,
70: 0x10, 0x11, NONE, 0x12, 0x14, 0x15, 0x16, 0x17,
71: 0x18, 0x1a, 0x1b, 0x1c, 0x1d, 0x1e, NONE, NONE,
72: };
73: /* Same as jamo_final, except that it excludes characters already
74: contained in jamo_initial. 11 characters instead of 27. */
75: static const unsigned char jamo_final_notinitial[32] = {
76: NONE, NONE, NONE, NONE, 0x03, NONE, 0x05, 0x06,
77: NONE, NONE, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f,
78: 0x10, NONE, NONE, NONE, 0x14, NONE, NONE, NONE,
79: NONE, NONE, NONE, NONE, NONE, NONE, NONE, NONE,
80: };
81:
82: /* Tables mapping 5-bit groups to packed indices. */
83: #define none -1
84: #define fill 0
85: static const signed char jamo_initial_index[32] = {
86: none, fill, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06,
87: 0x07, 0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e,
88: 0x0f, 0x10, 0x11, 0x12, 0x13, none, none, none,
89: none, none, none, none, none, none, none, none,
90: };
91: static const signed char jamo_medial_index[32] = {
92: none, none, fill, 0x01, 0x02, 0x03, 0x04, 0x05,
93: none, none, 0x06, 0x07, 0x08, 0x09, 0x0a, 0x0b,
94: none, none, 0x0c, 0x0d, 0x0e, 0x0f, 0x10, 0x11,
95: none, none, 0x12, 0x13, 0x14, 0x15, none, none,
96: };
97: static const signed char jamo_final_index[32] = {
98: none, fill, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06,
99: 0x07, 0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e,
100: 0x0f, 0x10, none, 0x11, 0x12, 0x13, 0x14, 0x15,
101: 0x16, 0x17, 0x18, 0x19, 0x1a, 0x1b, none, none,
102: };
103:
104: static int
105: johab_hangul_mbtowc (conv_t conv, ucs4_t *pwc, const unsigned char *s, int n)
106: {
107: unsigned char c1 = s[0];
108: if ((c1 >= 0x84 && c1 <= 0xd3)) {
109: if (n >= 2) {
110: unsigned char c2 = s[1];
111: if ((c2 >= 0x41 && c2 < 0x7f) || (c2 >= 0x81 && c2 < 0xff)) {
112: unsigned int johab = (c1 << 8) | c2;
113: unsigned int bitspart1 = (johab >> 10) & 31;
114: unsigned int bitspart2 = (johab >> 5) & 31;
115: unsigned int bitspart3 = johab & 31;
116: int index1 = jamo_initial_index[bitspart1];
117: int index2 = jamo_medial_index[bitspart2];
118: int index3 = jamo_final_index[bitspart3];
119: /* Exclude "none" values. */
120: if (index1 >= 0 && index2 >= 0 && index3 >= 0) {
121: /* Deal with "fill" values in initial or medial position. */
122: if (index1 == fill) {
123: if (index2 == fill) {
124: unsigned char jamo3 = jamo_final_notinitial[bitspart3];
125: if (jamo3 != NONE) {
126: *pwc = (ucs4_t) 0x3130 + jamo3;
127: return 2;
128: }
129: } else if (index3 == fill) {
130: unsigned char jamo2 = jamo_medial[bitspart2];
131: if (jamo2 != NONE && jamo2 != FILL) {
132: *pwc = (ucs4_t) 0x3130 + jamo2;
133: return 2;
134: }
135: }
136: /* Syllables composed only of medial and final don't exist. */
137: } else if (index2 == fill) {
138: if (index3 == fill) {
139: unsigned char jamo1 = jamo_initial[bitspart1];
140: if (jamo1 != NONE && jamo1 != FILL) {
141: *pwc = (ucs4_t) 0x3130 + jamo1;
142: return 2;
143: }
144: }
145: /* Syllables composed only of initial and final don't exist. */
146: } else {
147: /* index1 and index2 are not fill, but index3 may be fill. */
148: /* Nothing more to exclude. All 11172 code points are valid. */
149: *pwc = 0xac00 + ((index1 - 1) * 21 + (index2 - 1)) * 28 + index3;
150: return 2;
151: }
152: }
153: }
154: return RET_ILSEQ;
155: }
156: return RET_TOOFEW(0);
157: }
158: return RET_ILSEQ;
159: }
160:
161: /* 51 Jamo: 19 initial, 21 medial, 11 final not initial. */
162: static const unsigned short johab_hangul_page31[51] = {
163: 0x8841, 0x8c41, 0x8444, 0x9041, 0x8446, 0x8447, 0x9441, /*0x30-0x37*/
164: 0x9841, 0x9c41, 0x844a, 0x844b, 0x844c, 0x844d, 0x844e, 0x844f, /*0x38-0x3f*/
165: 0x8450, 0xa041, 0xa441, 0xa841, 0x8454, 0xac41, 0xb041, 0xb441, /*0x40-0x47*/
166: 0xb841, 0xbc41, 0xc041, 0xc441, 0xc841, 0xcc41, 0xd041, 0x8461, /*0x48-0x4f*/
167: 0x8481, 0x84a1, 0x84c1, 0x84e1, 0x8541, 0x8561, 0x8581, 0x85a1, /*0x50-0x57*/
168: 0x85c1, 0x85e1, 0x8641, 0x8661, 0x8681, 0x86a1, 0x86c1, 0x86e1, /*0x58-0x5f*/
169: 0x8741, 0x8761, 0x8781, 0x87a1, /*0x60-0x67*/
170: };
171:
172: /* Tables mapping packed indices to 5-bit groups. */
173: /* index1+1 = jamo_initial_index[bitspart1] <==>
174: bitspart1 = jamo_initial_index_inverse[index1] */
175: static const char jamo_initial_index_inverse[19] = {
176: 0x02, 0x03, 0x04, 0x05, 0x06, 0x07,
177: 0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f,
178: 0x10, 0x11, 0x12, 0x13, 0x14,
179: };
180: /* index2+1 = jamo_medial_index[bitspart2] <==>
181: bitspart2 = jamo_medial_index_inverse[index2] */
182: static const char jamo_medial_index_inverse[21] = {
183: 0x03, 0x04, 0x05, 0x06, 0x07,
184: 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f,
185: 0x12, 0x13, 0x14, 0x15, 0x16, 0x17,
186: 0x1a, 0x1b, 0x1c, 0x1d,
187: };
188: /* index3 = jamo_final_index[bitspart3] <==>
189: bitspart3 = jamo_final_index_inverse[index3] */
190: static const char jamo_final_index_inverse[28] = {
191: 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07,
192: 0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f,
193: 0x10, 0x11, 0x13, 0x14, 0x15, 0x16, 0x17,
194: 0x18, 0x19, 0x1a, 0x1b, 0x1c, 0x1d,
195: };
196:
197: static int
198: johab_hangul_wctomb (conv_t conv, unsigned char *r, ucs4_t wc, int n)
199: {
200: if (n >= 2) {
201: if (wc >= 0x3131 && wc < 0x3164) {
202: unsigned short c = johab_hangul_page31[wc-0x3131];
203: r[0] = (c >> 8); r[1] = (c & 0xff);
204: return 2;
205: } else if (wc >= 0xac00 && wc < 0xd7a4) {
206: unsigned int index1;
207: unsigned int index2;
208: unsigned int index3;
209: unsigned short c;
210: unsigned int tmp = wc - 0xac00;
211: index3 = tmp % 28; tmp = tmp / 28;
212: index2 = tmp % 21; tmp = tmp / 21;
213: index1 = tmp;
214: c = (((((1 << 5)
215: | jamo_initial_index_inverse[index1]) << 5)
216: | jamo_medial_index_inverse[index2]) << 5)
217: | jamo_final_index_inverse[index3];
218: r[0] = (c >> 8); r[1] = (c & 0xff);
219: return 2;
220: }
221: return RET_ILUNI;
222: }
223: return RET_TOOSMALL;
224: }
225:
226: /*
227: * Decomposition of JOHAB Hangul in one to three Johab Jamo elements.
228: */
229:
230: /* Decompose wc into r[0..2], and return the number of resulting Jamo elements.
231: Return RET_ILUNI if decomposition is not possible. */
232:
233: static int johab_hangul_decompose (conv_t conv, ucs4_t* r, ucs4_t wc)
234: {
235: unsigned char buf[2];
236: int ret = johab_hangul_wctomb(conv,buf,wc,2);
237: if (ret != RET_ILUNI) {
238: unsigned int hangul = (buf[0] << 8) | buf[1];
239: unsigned char jamo1 = jamo_initial[(hangul >> 10) & 31];
240: unsigned char jamo2 = jamo_medial[(hangul >> 5) & 31];
241: unsigned char jamo3 = jamo_final[hangul & 31];
242: if ((hangul >> 15) != 1) abort();
243: if (jamo1 != NONE && jamo2 != NONE && jamo3 != NONE) {
244: /* They are not all three == FILL because that would correspond to
245: johab = 0x8441, which doesn't exist. */
246: ucs4_t* p = r;
247: if (jamo1 != FILL)
248: *p++ = 0x3130 + jamo1;
249: if (jamo2 != FILL)
250: *p++ = 0x3130 + jamo2;
251: if (jamo3 != FILL)
252: *p++ = 0x3130 + jamo3;
253: return p-r;
254: }
255: }
256: return RET_ILUNI;
257: }
258:
259: #undef fill
260: #undef none
261: #undef FILL
262: #undef NONE
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