summaryrefslogtreecommitdiffstats
path: root/src/3rdparty/harfbuzz/src/harfbuzz-thai.c
blob: 039394a5a2a9bba9323a562aea3e5b09e103274b (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
/*
 * Copyright (C) 2008 Nokia Corporation and/or its subsidiary(-ies)
 *
 * This is part of HarfBuzz, an OpenType Layout engine library.
 *
 * Permission is hereby granted, without written agreement and without
 * license or royalty fees, to use, copy, modify, and distribute this
 * software and its documentation for any purpose, provided that the
 * above copyright notice and the following two paragraphs appear in
 * all copies of this software.
 *
 * IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE TO ANY PARTY FOR
 * DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES
 * ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN
 * IF THE COPYRIGHT HOLDER HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH
 * DAMAGE.
 *
 * THE COPYRIGHT HOLDER SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING,
 * BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
 * FITNESS FOR A PARTICULAR PURPOSE.  THE SOFTWARE PROVIDED HEREUNDER IS
 * ON AN "AS IS" BASIS, AND THE COPYRIGHT HOLDER HAS NO OBLIGATION TO
 * PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
 */

#include "harfbuzz-shaper.h"
#include "harfbuzz-shaper-private.h"
#include "harfbuzz-external.h"

#include <assert.h>
#include <stdio.h>

#define LIBTHAI_MAJOR   0

/*
 * if libthai changed please update these codes too.
 */
struct thcell_t {
    unsigned char base;      /**< base character */
    unsigned char hilo;      /**< upper/lower vowel/diacritic */
    unsigned char top;       /**< top-level mark */
};
typedef int (*th_brk_def) (const unsigned char*, int*, size_t);
typedef int (*th_render_cell_tis_def) (struct thcell_t cell, unsigned char res[], size_t res_sz, int is_decomp_am);
typedef int (*th_render_cell_win_def) (struct thcell_t cell, unsigned char res[], size_t res_sz, int is_decomp_am);
typedef int (*th_render_cell_mac_def) (struct thcell_t cell, unsigned char res[], size_t res_sz, int is_decomp_am);
typedef size_t (*th_next_cell_def) (const unsigned char *, size_t, struct thcell_t *, int);

/* libthai releated function handles */
static th_brk_def th_brk = 0;
static th_next_cell_def th_next_cell = 0;
static th_render_cell_tis_def th_render_cell_tis = 0;
static th_render_cell_win_def th_render_cell_win = 0;
static th_render_cell_mac_def th_render_cell_mac = 0;

static int init_libthai() {
    static HB_Bool initialized = false;
    if (!initialized && (!th_brk || !th_next_cell || !th_render_cell_tis || !th_render_cell_win || !th_render_cell_mac)) {
        th_brk = (th_brk_def) HB_Library_Resolve("thai", (int)LIBTHAI_MAJOR, "th_brk");
        th_next_cell = (th_next_cell_def)HB_Library_Resolve("thai", LIBTHAI_MAJOR, "th_next_cell");
        th_render_cell_tis = (th_render_cell_tis_def) HB_Library_Resolve("thai", (int)LIBTHAI_MAJOR, "th_render_cell_tis");
        th_render_cell_win = (th_render_cell_win_def) HB_Library_Resolve("thai", (int)LIBTHAI_MAJOR, "th_render_cell_win");
        th_render_cell_mac = (th_render_cell_mac_def) HB_Library_Resolve("thai", (int)LIBTHAI_MAJOR, "th_render_cell_mac");
        initialized = true;
    }
    if (th_brk && th_next_cell && th_render_cell_tis && th_render_cell_win && th_render_cell_mac)
        return 1;
    else
        return 0;
}

static void to_tis620(const HB_UChar16 *string, hb_uint32 len, const char *cstr)
{
    hb_uint32 i;
    unsigned char *result = (unsigned char *)cstr;

    for (i = 0; i < len; ++i) {
        if (string[i] <= 0xa0)
            result[i] = (unsigned char)string[i];
        else if (string[i] >= 0xe01 && string[i] <= 0xe5b)
            result[i] = (unsigned char)(string[i] - 0xe00 + 0xa0);
        else
            result[i] = (unsigned char)~0; // Same encoding as libthai uses for invalid chars
    }

    result[len] = 0;
}

/*
 * ---------------------------------------------------------------------------
 * Thai Shaper / Attributes
 * ---------------------------------------------------------------------------
 */

/*
 * USe basic_features prepare for future adding.
 */
#ifndef NO_OPENTYPE
static const HB_OpenTypeFeature thai_features[] = {
    { HB_MAKE_TAG('c', 'c', 'm', 'p'), CcmpProperty },
    { HB_MAKE_TAG('l', 'i', 'g', 'a'), CcmpProperty },
    { HB_MAKE_TAG('c', 'l', 'i', 'g'), CcmpProperty },
    {0, 0}
};
#endif

/* TIS-to-Unicode glyph maps for characters 0x80-0xff */
static int tis620_0[128] = {
    /**/ 0,      0,      0,      0,      0,      0,      0,      0,
    /**/ 0,      0,      0,      0,      0,      0,      0,      0,
    /**/ 0,      0,      0,      0,      0,      0,      0,      0,
    /**/ 0,      0,      0,      0,      0,      0,      0,      0,
    0x0020, 0x0e01, 0x0e02, 0x0e03, 0x0e04, 0x0e05, 0x0e06, 0x0e07,
    0x0e08, 0x0e09, 0x0e0a, 0x0e0b, 0x0e0c, 0x0e0d, 0x0e0e, 0x0e0f,
    0x0e10, 0x0e11, 0x0e12, 0x0e13, 0x0e14, 0x0e15, 0x0e16, 0x0e17,
    0x0e18, 0x0e19, 0x0e1a, 0x0e1b, 0x0e1c, 0x0e1d, 0x0e1e, 0x0e1f,
    0x0e20, 0x0e21, 0x0e22, 0x0e23, 0x0e24, 0x0e25, 0x0e26, 0x0e27,
    0x0e28, 0x0e29, 0x0e2a, 0x0e2b, 0x0e2c, 0x0e2d, 0x0e2e, 0x0e2f,
    0x0e30, 0x0e31, 0x0e32, 0x0e33, 0x0e34, 0x0e35, 0x0e36, 0x0e37,
    0x0e38, 0x0e39, 0x0e3a,      0,      0,      0,      0, 0x0e3f,
    0x0e40, 0x0e41, 0x0e42, 0x0e43, 0x0e44, 0x0e45, 0x0e46, 0x0e47,
    0x0e48, 0x0e49, 0x0e4a, 0x0e4b, 0x0e4c, 0x0e4d, 0x0e4e, 0x0e4f,
    0x0e50, 0x0e51, 0x0e52, 0x0e53, 0x0e54, 0x0e55, 0x0e56, 0x0e57,
    0x0e58, 0x0e59, 0x0e5a, 0x0e5b,      0,      0,      0,      0
};

static int tis620_1[128] = {
    0xf89e,      0,      0, 0xf88c, 0xf88f, 0xf892, 0xf895, 0xf898,
    0xf88b, 0xf88e, 0xf891, 0xf894, 0xf897,      0,      0, 0xf899,
    0xf89a,      0, 0xf884, 0xf889, 0xf885, 0xf886, 0xf887, 0xf888,
    0xf88a, 0xf88d, 0xf890, 0xf893, 0xf896,      0,      0,      0,
    /**/ 0, 0x0e01, 0x0e02, 0x0e03, 0x0e04, 0x0e05, 0x0e06, 0x0e07,
    0x0e08, 0x0e09, 0x0e0a, 0x0e0b, 0x0e0c, 0x0e0d, 0x0e0e, 0x0e0f,
    0x0e10, 0x0e11, 0x0e12, 0x0e13, 0x0e14, 0x0e15, 0x0e16, 0x0e17,
    0x0e18, 0x0e19, 0x0e1a, 0x0e1b, 0x0e1c, 0x0e1d, 0x0e1e, 0x0e1f,
    0x0e20, 0x0e21, 0x0e22, 0x0e23, 0x0e24, 0x0e25, 0x0e26, 0x0e27,
    0x0e28, 0x0e29, 0x0e2a, 0x0e2b, 0x0e2c, 0x0e2d, 0x0e2e, 0x0e2f,
    0x0e30, 0x0e31, 0x0e32, 0x0e33, 0x0e34, 0x0e35, 0x0e36, 0x0e37,
    0x0e38, 0x0e39, 0x0e3a,      0,      0,      0,      0, 0x0e3f,
    0x0e40, 0x0e41, 0x0e42, 0x0e43, 0x0e44, 0x0e45, 0x0e46, 0x0e47,
    0x0e48, 0x0e49, 0x0e4a, 0x0e4b, 0x0e4c, 0x0e4d,      0, 0x0e4f,
    0x0e50, 0x0e51, 0x0e52, 0x0e53, 0x0e54, 0x0e55, 0x0e56, 0x0e57,
    0x0e58, 0x0e59,      0,      0, 0xf89b, 0xf89c, 0xf89d,      0
};

static int tis620_2[128] = {
    0xf700, 0xf701, 0xf702, 0xf703, 0xf704, 0x2026, 0xf705, 0xf706,
    0xf707, 0xf708, 0xf709, 0xf70a, 0xf70b, 0xf70c, 0xf70d, 0xf70e,
    0xf70f, 0x2018, 0x2019, 0x201c, 0x201d, 0x2022, 0x2013, 0x2014,
    0xf710, 0xf711, 0xf712, 0xf713, 0xf714, 0xf715, 0xf716, 0xf717,
    0x00a0, 0x0e01, 0x0e02, 0x0e03, 0x0e04, 0x0e05, 0x0e06, 0x0e07,
    0x0e08, 0x0e09, 0x0e0a, 0x0e0b, 0x0e0c, 0x0e0d, 0x0e0e, 0x0e0f,
    0x0e10, 0x0e11, 0x0e12, 0x0e13, 0x0e14, 0x0e15, 0x0e16, 0x0e17,
    0x0e18, 0x0e19, 0x0e1a, 0x0e1b, 0x0e1c, 0x0e1d, 0x0e1e, 0x0e1f,
    0x0e20, 0x0e21, 0x0e22, 0x0e23, 0x0e24, 0x0e25, 0x0e26, 0x0e27,
    0x0e28, 0x0e29, 0x0e2a, 0x0e2b, 0x0e2c, 0x0e2d, 0x0e2e, 0x0e2f,
    0x0e30, 0x0e31, 0x0e32, 0x0e33, 0x0e34, 0x0e35, 0x0e36, 0x0e37,
    0x0e38, 0x0e39, 0x0e3a,      0,      0,      0,      0, 0x0e3f,
    0x0e40, 0x0e41, 0x0e42, 0x0e43, 0x0e44, 0x0e45, 0x0e46, 0x0e47,
    0x0e48, 0x0e49, 0x0e4a, 0x0e4b, 0x0e4c, 0x0e4d, 0x0e4e, 0x0e4f,
    0x0e50, 0x0e51, 0x0e52, 0x0e53, 0x0e54, 0x0e55, 0x0e56, 0x0e57,
    0x0e58, 0x0e59, 0x0e5a, 0x0e5b, 0xf718, 0xf719, 0xf71a,      0
};

enum ThaiFontType {
    TIS,
    WIN,
    MAC,
};

static int thai_get_glyph_index (ThaiFontType font_type, unsigned char c)
{
    switch (font_type){
        case TIS: return (c & 0x80) ? tis620_0[c & 0x7f] : c;
        case WIN: return (c & 0x80) ? tis620_1[c & 0x7f] : c;
        case MAC: return (c & 0x80) ? tis620_2[c & 0x7f] : c;
        default:  return 0;
    }
}

static int thai_contain_glyphs (HB_ShaperItem *shaper_item, const int glyph_map[128])
{
    unsigned char c;

    for (c = 0; c < 0x80; c++) {
        if ( glyph_map[c] ) {
            if ( !shaper_item->font->klass->canRender (shaper_item->font, (HB_UChar16 *) &glyph_map[c], 1) )
                return 0;
        }
    }
    return 1;
}

static ThaiFontType getThaiFontType(HB_ShaperItem *shaper_item)
{
    if ( thai_contain_glyphs (shaper_item, tis620_2) )
        return MAC;
    else if ( thai_contain_glyphs (shaper_item, tis620_1) )
        return WIN;
    else
        return TIS;
}

/*
 * convert to the correct display level of THAI vowels and marks.
 */
static HB_Bool HB_ThaiConvertStringToGlyphIndices (HB_ShaperItem *item)
{
    char s[128];
    char *cstr = s;
    const HB_UChar16 *string = item->string + item->item.pos;
    const hb_uint32 len = item->item.length;
    unsigned short *logClusters = item->log_clusters;
    hb_uint32 i = 0, slen = 0;

    if (!init_libthai())
        return HB_BasicShape (item);

    if (len >= 128)
        cstr = (char *)malloc(len*sizeof(char) + 1);

    if (!cstr)
        return HB_BasicShape (item);

    to_tis620(string, len, cstr);

    /* Get font type */
    static ThaiFontType font_type;
    static HB_Font itemFont;
    if (itemFont != item->font) {
        font_type = getThaiFontType (item);
        itemFont = item->font;
    }

    /* allocate temporary glyphs buffers */
    HB_STACKARRAY (HB_UChar16, glyphString, (item->item.length * 2));

    while (i < item->item.length) {
        struct thcell_t tis_cell;
        unsigned char rglyphs[4];
        int cell_length;
        int lgn = 0;
        HB_Bool haveSaraAm = false;

        cell_length = th_next_cell ((const unsigned char *)cstr + i, len - i, &tis_cell, true); /* !item->fixedPitch); */
        haveSaraAm  = (cstr[i + cell_length - 1] == (char)0xd3);

        /* set shaper item's log_clusters */
        logClusters[i] = slen;
        for (int j = 1; j < cell_length; j++) {
            logClusters[i + j] = logClusters[i];
        }

        /* Find Logical Glyphs by font type */
        switch (font_type) {
            case TIS: lgn = th_render_cell_tis (tis_cell, rglyphs, sizeof(rglyphs) / sizeof(rglyphs[0]), true); break;
            case WIN: lgn = th_render_cell_mac (tis_cell, rglyphs, sizeof(rglyphs) / sizeof(rglyphs[0]), true); break;
            case MAC: lgn = th_render_cell_win (tis_cell, rglyphs, sizeof(rglyphs) / sizeof(rglyphs[0]), true); break;
        }

        /* Add glyphs to glyphs string and setting some attributes */
        for (int lgi = 0; lgi < lgn; lgi++) {
            if ( rglyphs[lgi] == 0xdd/*TH_BLANK_BASE_GLYPH*/ ) {
                glyphString[slen++] = C_DOTTED_CIRCLE;
            } else if (cstr[i] == (signed char)~0) {
                // The only glyphs that should be passed to this function that cannot be mapped to
                // tis620 are the ones of type Inherited class.  Pass these glyphs untouched.
                glyphString[slen++] = string[i];
                if (string[i] == 0x200D || string[i] == 0x200C) {
                    // Check that we do not run out of bounds when setting item->attributes.  If we do
                    // run out of bounds then this function will return false, the necessary amount of
                    // memory is reallocated, and this function will then be called again.
                    if (slen <= item->num_glyphs)
                        item->attributes[slen-1].dontPrint = true; // Hide ZWJ and ZWNJ characters
                }
            } else {
                glyphString[slen++] = (HB_UChar16) thai_get_glyph_index (font_type, rglyphs[lgi]);
            }
        }

        /* Special case to handle U+0E33 (SARA AM, ำ): SARA AM is normally written at the end of a
         * word with a base character and an optional top character before it. For example, U+0E0B
         * (base), U+0E49 (top), U+0E33 (SARA AM). The sequence should be converted to 4 glyphs:
         * base, hilo (the little circle in the top left part of SARA AM, NIKHAHIT), top, then the
         * right part of SARA AM (SARA AA).
         *
         * The painting process finds out the starting glyph and ending glyph of a character
         * sequence by checking the logClusters array. In this case, logClusters array should
         * ideally be [ 0, 1, 3 ] so that glyphsStart = 0 and glyphsEnd = 3 (slen - 1) to paint out
         * all the glyphs generated.
         *
         * A special case in this special case is when we have no base character. When an isolated
         * SARA AM is processed (cell_length = 1), libthai will produce 3 glyphs: dotted circle
         * (indicates that the base is empty), NIKHAHIT then SARA AA. If logClusters[0] = 1, it will
         * paint from the second glyph in the glyphs array. So in this case logClusters[0] should
         * point to the first glyph it produces, aka. the dotted circle. */
        if (haveSaraAm) {
            logClusters[i + cell_length - 1] = cell_length == 1 ? slen - 3 : slen - 1;
            if (tis_cell.top != 0) {
                if (cell_length > 1) {
                    /* set the logClusters[top character] to slen - 2 as it points to the second to
                     * lastglyph (slen - 2) */
                    logClusters[i + cell_length - 2] = slen - 2;
                }
            }
            /* check for overflow */
            if (logClusters[i + cell_length - 1] > slen)
                logClusters[i + cell_length - 1] = 0;
        }

        i += cell_length;
    }
    glyphString[slen] = (HB_UChar16) '\0';

    /* for check, should reallocate space or not */
    HB_Bool spaceOK = (item->num_glyphs >= slen);

    /* Convert to Glyph indices */
    HB_Bool haveGlyphs = item->font->klass->convertStringToGlyphIndices (
                                          item->font,
                                          glyphString, slen,
                                          item->glyphs, &item->num_glyphs,
                                          item->shaperFlags);

    HB_FREE_STACKARRAY (glyphString);

    if (len >= 128)
        free(cstr);

    return (haveGlyphs && spaceOK);
}

/*
 * set the glyph attributes heuristically.
 */
static void HB_ThaiHeuristicSetGlyphAttributes (HB_ShaperItem *item)
{
    /* Set Glyph Attributes */
    hb_uint32 iCluster = 0;
    hb_uint32 length = item->item.length;
    while (iCluster < length) {
        int cluster_start = item->log_clusters[iCluster];
        ++iCluster;
        while (iCluster < length && item->log_clusters[iCluster] == cluster_start) {
            ++iCluster;
        }
        int cluster_end = (iCluster < length) ? item->log_clusters[iCluster] : item->num_glyphs;
        item->attributes[cluster_start].clusterStart = true;
        for (int i = cluster_start + 1; i < cluster_end; i++) {
            item->attributes[i].clusterStart = false;
        }
    }
}

/*
 * THAI Shaping.
 */
HB_Bool HB_ThaiShape (HB_ShaperItem *shaper_item)
{
    if ( !HB_ThaiConvertStringToGlyphIndices (shaper_item) )
        return false;

    HB_ThaiHeuristicSetGlyphAttributes (shaper_item);

#ifndef NO_OPENTYPE
    const int availableGlyphs = shaper_item->num_glyphs;
    if ( HB_SelectScript (shaper_item, thai_features) ) {
        HB_OpenTypeShape (shaper_item, /*properties*/0);
        return HB_OpenTypePosition (shaper_item, availableGlyphs, /*doLogClusters*/true);
    }
#endif

    HB_HeuristicPosition (shaper_item);
    return true;
}

/*
 * Thai Attributes: computes Word Break, Word Boundary and Char stop for THAI.
 */
static void HB_ThaiAssignAttributes(const HB_UChar16 *string, hb_uint32 len, HB_CharAttributes *attributes)
{
    char s[128];
    char *cstr = s;
    int *break_positions = 0;
    int brp[128];
    int brp_size = 0;
    hb_uint32 numbreaks, i, j, cell_length;
    struct thcell_t tis_cell;

    if (!init_libthai())
        return ;

    if (len >= 128)
        cstr = (char *)malloc(len*sizeof(char) + 1);

    to_tis620(string, len, cstr);

    for (i = 0; i < len; ++i) {
        attributes[i].lineBreakType = HB_NoBreak;
        attributes[i].wordBoundary = FALSE;
    }

    if (len > 128) {
        break_positions = (int*) malloc (sizeof(int) * len);
        memset (break_positions, 0, sizeof(int) * len);
        brp_size = len;
    }
    else {
        break_positions = brp;
        brp_size = 128;
    }

    if (break_positions) {
        attributes[0].wordBoundary = TRUE;
        numbreaks = th_brk((const unsigned char *)cstr, break_positions, brp_size);
        for (i = 0; i < numbreaks; ++i) {
            attributes[break_positions[i]].wordBoundary = TRUE;
            if (break_positions[i] > 0)
                attributes[break_positions[i]-1].lineBreakType = HB_Break;
        }

        if (break_positions != brp)
            free(break_positions);
    }

    /* manage charStop */
    i = 0;
    while (i < len) {
        cell_length = th_next_cell((const unsigned char *)cstr + i, len - i, &tis_cell, true);

        attributes[i].charStop = true;
        for (j = 1; j < cell_length; j++)
            attributes[i + j].charStop = false;

        /* Set charStop for SARA AM */
        if (cstr[i + cell_length - 1] == (char)0xd3)
            attributes[i + cell_length - 1].charStop = true;

        i += cell_length;
    }

    if (len >= 128)
        free(cstr);
}

void HB_ThaiAttributes(HB_Script script, const HB_UChar16 *text, hb_uint32 from, hb_uint32 len, HB_CharAttributes *attributes)
{
    assert(script == HB_Script_Thai);
    const HB_UChar16 *uc = text + from;
    attributes += from;
    HB_UNUSED(script);
    HB_ThaiAssignAttributes(uc, len, attributes);
}