1/*
2 *
3 * (C) Copyright IBM Corp. 1998-2004 - All Rights Reserved
4 *
5 */
6
7#include "LETypes.h"
8#include "LEGlyphFilter.h"
9#include "OpenTypeTables.h"
10#include "LEGlyphStorage.h"
11#include "ThaiShaping.h"
12
13U_NAMESPACE_BEGIN
14
15enum {
16    CH_SPACE        = 0x0020,
17    CH_YAMAKKAN     = 0x0E4E,
18    CH_MAI_HANAKAT  = 0x0E31,
19    CH_SARA_AA      = 0x0E32,
20    CH_SARA_AM      = 0x0E33,
21    CH_SARA_UEE     = 0x0E37,
22    CH_MAITAIKHU    = 0x0E47,
23    CH_NIKHAHIT     = 0x0E4D,
24    CH_SARA_U       = 0x0E38,
25    CH_PHINTHU      = 0x0E3A,
26    CH_YO_YING      = 0x0E0D,
27    CH_THO_THAN     = 0x0E10,
28    CH_DOTTED_CIRCLE = 0x25CC
29};
30
31    le_uint8 ThaiShaping::getCharClass(LEUnicode ch)
32{
33    le_uint8 charClass = NON;
34
35    if (ch >= 0x0E00 && ch <= 0x0E5B) {
36        charClass = classTable[ch - 0x0E00];
37    }
38
39    return charClass;
40}
41
42
43LEUnicode ThaiShaping::leftAboveVowel(LEUnicode vowel, le_uint8 glyphSet)
44{
45    static const LEUnicode leftAboveVowels[][7] = {
46        {0x0E61, 0x0E32, 0x0E33, 0x0E64, 0x0E65, 0x0E66, 0x0E67},
47        {0xF710, 0x0E32, 0x0E33, 0xF701, 0xF702, 0xF703, 0xF704},
48        {0xF884, 0x0E32, 0x0E33, 0xF885, 0xF886, 0xF887, 0xF788},
49        {0x0E31, 0x0E32, 0x0E33, 0x0E34, 0x0E35, 0x0E36, 0x0E37}
50    };
51
52    if (vowel >= CH_MAI_HANAKAT && vowel <= CH_SARA_UEE) {
53        return leftAboveVowels[glyphSet][vowel - CH_MAI_HANAKAT];
54    }
55
56    if (vowel == CH_YAMAKKAN && glyphSet == 0) {
57        return 0x0E7E;
58    }
59
60    return vowel;
61}
62
63LEUnicode ThaiShaping::lowerRightTone(LEUnicode tone, le_uint8 glyphSet)
64{
65    static const LEUnicode lowerRightTones[][7] = {
66        {0x0E68, 0x0E69, 0x0E6A, 0x0E6B, 0x0E6C, 0x0E6D, 0x0E6E},
67        {0x0E47, 0xF70A, 0xF70B, 0xF70C, 0xF70D, 0xF70E, 0x0E4D},
68        {0x0E47, 0xF88B, 0xF88E, 0xF891, 0xF894, 0xF897, 0x0E4D},
69        {0x0E47, 0x0E48, 0x0E49, 0x0E4A, 0x0E4B, 0x0E4C, 0x0E4D}
70    };
71
72    if (tone >= CH_MAITAIKHU && tone <= CH_NIKHAHIT) {
73        return lowerRightTones[glyphSet][tone - CH_MAITAIKHU];
74    }
75
76    return tone;
77}
78
79LEUnicode ThaiShaping::lowerLeftTone(LEUnicode tone, le_uint8 glyphSet)
80{
81    static const LEUnicode lowerLeftTones[][7] = {
82        {0x0E76, 0x0E77, 0x0E78, 0x0E79, 0x0E7A, 0x0E7B, 0x0E7C},
83        {0xF712, 0xF705, 0xF706, 0xF707, 0xF708, 0xF709, 0xF711},
84        {0xF889, 0xF88C, 0xF88F, 0xF892, 0xF895, 0xF898, 0xF899},
85        {0x0E47, 0x0E48, 0x0E49, 0x0E4A, 0x0E4B, 0x0E4C, 0x0E4D}
86    };
87
88    if (tone >= CH_MAITAIKHU && tone <= CH_NIKHAHIT) {
89        return lowerLeftTones[glyphSet][tone - CH_MAITAIKHU];
90    }
91
92    return tone;
93}
94
95LEUnicode ThaiShaping::upperLeftTone(LEUnicode tone, le_uint8 glyphSet)
96{
97    static const LEUnicode upperLeftTones[][7] = {
98        {0x0E6F, 0x0E70, 0x0E71, 0x0E72, 0x0E73, 0x0E74, 0x0E75},
99        {0xF712, 0xF713, 0xF714, 0xF715, 0xF716, 0xF717, 0xF711},
100        {0xF889, 0xF88A, 0xF88D, 0xF890, 0xF893, 0xF896, 0xF899},
101        {0x0E47, 0x0E48, 0x0E49, 0x0E4A, 0x0E4B, 0x0E4C, 0x0E4D}
102    };
103
104    if (tone >= CH_MAITAIKHU && tone <= CH_NIKHAHIT) {
105        return upperLeftTones[glyphSet][tone - CH_MAITAIKHU];
106    }
107
108    return tone;
109}
110
111LEUnicode ThaiShaping::lowerBelowVowel(LEUnicode vowel, le_uint8 glyphSet)
112{
113    static const LEUnicode lowerBelowVowels[][3] = {
114        {0x0E3C, 0x0E3D, 0x0E3E},
115        {0xF718, 0xF719, 0xF71A},
116        {0x0E38, 0x0E39, 0x0E3A},
117        {0x0E38, 0x0E39, 0x0E3A}
118
119    };
120
121    if (vowel >= CH_SARA_U && vowel <= CH_PHINTHU) {
122        return lowerBelowVowels[glyphSet][vowel - CH_SARA_U];
123    }
124
125    return vowel;
126}
127
128LEUnicode ThaiShaping::noDescenderCOD(LEUnicode cod, le_uint8 glyphSet)
129{
130    static const LEUnicode noDescenderCODs[][4] = {
131        {0x0E60, 0x0E0E, 0x0E0F, 0x0E63},
132        {0xF70F, 0x0E0E, 0x0E0F, 0xF700},
133        {0x0E0D, 0x0E0E, 0x0E0F, 0x0E10},
134        {0x0E0D, 0x0E0E, 0x0E0F, 0x0E10}
135
136    };
137
138    if (cod >= CH_YO_YING && cod <= CH_THO_THAN) {
139        return noDescenderCODs[glyphSet][cod - CH_YO_YING];
140    }
141
142    return cod;
143}
144
145le_uint8 ThaiShaping::doTransition (StateTransition transition, LEUnicode currChar, le_int32 inputIndex, le_uint8 glyphSet,
146        LEUnicode errorChar, LEUnicode *outputBuffer, LEGlyphStorage &glyphStorage, le_int32 &outputIndex)
147{
148    LEErrorCode success = LE_NO_ERROR;
149
150    switch (transition.action) {
151    case tA:
152        glyphStorage.setCharIndex(outputIndex, inputIndex, success);
153        outputBuffer[outputIndex++] = currChar;
154        break;
155
156    case tC:
157        glyphStorage.setCharIndex(outputIndex, inputIndex, success);
158        outputBuffer[outputIndex++] = currChar;
159        break;
160
161    case tD:
162        glyphStorage.setCharIndex(outputIndex, inputIndex, success);
163        outputBuffer[outputIndex++] = leftAboveVowel(currChar, glyphSet);
164        break;
165
166    case tE:
167        glyphStorage.setCharIndex(outputIndex, inputIndex, success);
168        outputBuffer[outputIndex++] = lowerRightTone(currChar, glyphSet);
169        break;
170
171    case tF:
172        glyphStorage.setCharIndex(outputIndex, inputIndex, success);
173        outputBuffer[outputIndex++] = lowerLeftTone(currChar, glyphSet);
174        break;
175
176    case tG:
177        glyphStorage.setCharIndex(outputIndex, inputIndex, success);
178        outputBuffer[outputIndex++] = upperLeftTone(currChar, glyphSet);
179        break;
180
181    case tH:
182    {
183        LEUnicode cod = outputBuffer[outputIndex - 1];
184        LEUnicode coa = noDescenderCOD(cod, glyphSet);
185
186        if (cod != coa) {
187            outputBuffer[outputIndex - 1] = coa;
188
189            glyphStorage.setCharIndex(outputIndex, inputIndex, success);
190            outputBuffer[outputIndex++] = currChar;
191            break;
192        }
193
194        glyphStorage.setCharIndex(outputIndex, inputIndex, success);
195        outputBuffer[outputIndex++] = lowerBelowVowel(currChar, glyphSet);
196        break;
197    }
198
199    case tR:
200        glyphStorage.setCharIndex(outputIndex, inputIndex, success);
201        outputBuffer[outputIndex++] = errorChar;
202
203        glyphStorage.setCharIndex(outputIndex, inputIndex, success);
204        outputBuffer[outputIndex++] = currChar;
205        break;
206
207    case tS:
208        if (currChar == CH_SARA_AM) {
209            glyphStorage.setCharIndex(outputIndex, inputIndex, success);
210            outputBuffer[outputIndex++] = errorChar;
211        }
212
213        glyphStorage.setCharIndex(outputIndex, inputIndex, success);
214        outputBuffer[outputIndex++] = currChar;
215        break;
216
217    default:
218        // FIXME: if we get here, there's an error
219        // in the state table!
220        glyphStorage.setCharIndex(outputIndex, inputIndex, success);
221        outputBuffer[outputIndex++] = currChar;
222        break;
223     }
224
225     return transition.nextState;
226}
227
228le_uint8 ThaiShaping::getNextState(LEUnicode ch, le_uint8 prevState, le_int32 inputIndex, le_uint8 glyphSet, LEUnicode errorChar,
229                              le_uint8 &charClass, LEUnicode *output, LEGlyphStorage &glyphStorage, le_int32 &outputIndex)
230{
231    StateTransition transition;
232
233    charClass = getCharClass(ch);
234    transition = getTransition(prevState, charClass);
235
236    return doTransition(transition, ch, inputIndex, glyphSet, errorChar, output, glyphStorage, outputIndex);
237}
238
239le_bool ThaiShaping::isLegalHere(LEUnicode ch, le_uint8 prevState)
240{
241    le_uint8 charClass = getCharClass(ch);
242    StateTransition transition = getTransition(prevState, charClass);
243
244    switch (transition.action) {
245    case tA:
246    case tC:
247    case tD:
248    case tE:
249    case tF:
250    case tG:
251    case tH:
252        return TRUE;
253
254    case tR:
255    case tS:
256        return FALSE;
257
258    default:
259        // FIXME: if we get here, there's an error
260        // in the state table!
261        return FALSE;
262    }
263}
264
265le_int32 ThaiShaping::compose(const LEUnicode *input, le_int32 offset, le_int32 charCount, le_uint8 glyphSet,
266                          LEUnicode errorChar, LEUnicode *output, LEGlyphStorage &glyphStorage)
267{
268    le_uint8 state = 0;
269    le_int32 inputIndex;
270    le_int32 outputIndex = 0;
271    le_uint8 conState = 0xFF;
272    le_int32 conInput = -1;
273    le_int32 conOutput = -1;
274
275    for (inputIndex = 0; inputIndex < charCount; inputIndex += 1) {
276        LEUnicode ch = input[inputIndex + offset];
277        le_uint8 charClass;
278
279        // Decompose SARA AM into NIKHAHIT + SARA AA
280        if (ch == CH_SARA_AM && isLegalHere(ch, state)) {
281            outputIndex = conOutput;
282            state = getNextState(CH_NIKHAHIT, conState, inputIndex, glyphSet, errorChar, charClass,
283                output, glyphStorage, outputIndex);
284
285            for (int j = conInput + 1; j < inputIndex; j += 1) {
286                ch = input[j + offset];
287                state = getNextState(ch, state, j, glyphSet, errorChar, charClass,
288                    output, glyphStorage, outputIndex);
289            }
290
291            ch = CH_SARA_AA;
292        }
293
294        state = getNextState(ch, state, inputIndex, glyphSet, errorChar, charClass,
295            output, glyphStorage, outputIndex);
296
297        if (charClass >= CON && charClass <= COD) {
298            conState = state;
299            conInput = inputIndex;
300            conOutput = outputIndex;
301        }
302    }
303
304    return outputIndex;
305}
306
307U_NAMESPACE_END
308