1 /*
2 * Copyright (C) 2015 The Qt Company Ltd
3 *
4 * This is part of HarfBuzz, an OpenType Layout engine library.
5 *
6 * Permission is hereby granted, without written agreement and without
7 * license or royalty fees, to use, copy, modify, and distribute this
8 * software and its documentation for any purpose, provided that the
9 * above copyright notice and the following two paragraphs appear in
10 * all copies of this software.
11 *
12 * IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE TO ANY PARTY FOR
13 * DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES
14 * ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN
15 * IF THE COPYRIGHT HOLDER HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH
16 * DAMAGE.
17 *
18 * THE COPYRIGHT HOLDER SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING,
19 * BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
20 * FITNESS FOR A PARTICULAR PURPOSE. THE SOFTWARE PROVIDED HEREUNDER IS
21 * ON AN "AS IS" BASIS, AND THE COPYRIGHT HOLDER HAS NO OBLIGATION TO
22 * PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
23 */
24
25 #include "harfbuzz-shaper.h"
26 #include "harfbuzz-shaper-private.h"
27
28 #include <assert.h>
29
30 /*
31 tibetan syllables are of the form:
32 head position consonant
33 first sub-joined consonant
34 ....intermediate sub-joined consonants (if any)
35 last sub-joined consonant
36 sub-joined vowel (a-chung U+0F71)
37 standard or compound vowel sign (or 'virama' for devanagari transliteration)
38 */
39
40 typedef enum {
41 TibetanOther,
42 TibetanHeadConsonant,
43 TibetanSubjoinedConsonant,
44 TibetanSubjoinedVowel,
45 TibetanVowel
46 } TibetanForm;
47
48 /* this table starts at U+0f40 */
49 static const unsigned char tibetanForm[0x80] = {
50 TibetanHeadConsonant, TibetanHeadConsonant, TibetanHeadConsonant, TibetanHeadConsonant,
51 TibetanHeadConsonant, TibetanHeadConsonant, TibetanHeadConsonant, TibetanHeadConsonant,
52 TibetanHeadConsonant, TibetanHeadConsonant, TibetanHeadConsonant, TibetanHeadConsonant,
53 TibetanHeadConsonant, TibetanHeadConsonant, TibetanHeadConsonant, TibetanHeadConsonant,
54
55 TibetanHeadConsonant, TibetanHeadConsonant, TibetanHeadConsonant, TibetanHeadConsonant,
56 TibetanHeadConsonant, TibetanHeadConsonant, TibetanHeadConsonant, TibetanHeadConsonant,
57 TibetanHeadConsonant, TibetanHeadConsonant, TibetanHeadConsonant, TibetanHeadConsonant,
58 TibetanHeadConsonant, TibetanHeadConsonant, TibetanHeadConsonant, TibetanHeadConsonant,
59
60 TibetanHeadConsonant, TibetanHeadConsonant, TibetanHeadConsonant, TibetanHeadConsonant,
61 TibetanHeadConsonant, TibetanHeadConsonant, TibetanHeadConsonant, TibetanHeadConsonant,
62 TibetanHeadConsonant, TibetanHeadConsonant, TibetanHeadConsonant, TibetanHeadConsonant,
63 TibetanOther, TibetanOther, TibetanOther, TibetanOther,
64
65 TibetanOther, TibetanVowel, TibetanVowel, TibetanVowel,
66 TibetanVowel, TibetanVowel, TibetanVowel, TibetanVowel,
67 TibetanVowel, TibetanVowel, TibetanVowel, TibetanVowel,
68 TibetanVowel, TibetanVowel, TibetanVowel, TibetanVowel,
69
70 TibetanVowel, TibetanVowel, TibetanVowel, TibetanVowel,
71 TibetanVowel, TibetanVowel, TibetanVowel, TibetanVowel,
72 TibetanOther, TibetanOther, TibetanOther, TibetanOther,
73 TibetanOther, TibetanOther, TibetanOther, TibetanOther,
74
75 TibetanSubjoinedConsonant, TibetanSubjoinedConsonant, TibetanSubjoinedConsonant, TibetanSubjoinedConsonant,
76 TibetanSubjoinedConsonant, TibetanSubjoinedConsonant, TibetanSubjoinedConsonant, TibetanSubjoinedConsonant,
77 TibetanSubjoinedConsonant, TibetanSubjoinedConsonant, TibetanSubjoinedConsonant, TibetanSubjoinedConsonant,
78 TibetanSubjoinedConsonant, TibetanSubjoinedConsonant, TibetanSubjoinedConsonant, TibetanSubjoinedConsonant,
79
80 TibetanSubjoinedConsonant, TibetanSubjoinedConsonant, TibetanSubjoinedConsonant, TibetanSubjoinedConsonant,
81 TibetanSubjoinedConsonant, TibetanSubjoinedConsonant, TibetanSubjoinedConsonant, TibetanSubjoinedConsonant,
82 TibetanSubjoinedConsonant, TibetanSubjoinedConsonant, TibetanSubjoinedConsonant, TibetanSubjoinedConsonant,
83 TibetanSubjoinedConsonant, TibetanSubjoinedConsonant, TibetanSubjoinedConsonant, TibetanSubjoinedConsonant,
84
85 TibetanSubjoinedConsonant, TibetanSubjoinedConsonant, TibetanSubjoinedConsonant, TibetanSubjoinedConsonant,
86 TibetanSubjoinedConsonant, TibetanSubjoinedConsonant, TibetanSubjoinedConsonant, TibetanSubjoinedConsonant,
87 TibetanSubjoinedConsonant, TibetanSubjoinedConsonant, TibetanSubjoinedConsonant, TibetanSubjoinedConsonant,
88 TibetanSubjoinedConsonant, TibetanOther, TibetanOther, TibetanOther
89 };
90
91
92 #define tibetan_form(c) \
93 ((c) >= 0x0f40 && (c) < 0x0fc0 ? (TibetanForm)tibetanForm[(c) - 0x0f40] : TibetanOther)
94
95 #ifndef NO_OPENTYPE
96 static const HB_OpenTypeFeature tibetan_features[] = {
97 { HB_MAKE_TAG('c', 'c', 'm', 'p'), CcmpProperty },
98 { HB_MAKE_TAG('a', 'b', 'v', 's'), AboveSubstProperty },
99 { HB_MAKE_TAG('b', 'l', 'w', 's'), BelowSubstProperty },
100 { HB_MAKE_TAG('c', 'a', 'l', 't'), CaltProperty },
101 {0, 0}
102 };
103 #endif
104
tibetan_shape_syllable(HB_Bool openType,HB_ShaperItem * item,HB_Bool invalid)105 static HB_Bool tibetan_shape_syllable(HB_Bool openType, HB_ShaperItem *item, HB_Bool invalid)
106 {
107 hb_uint32 i;
108 const HB_UChar16 *str = item->string + item->item.pos;
109 int len = item->item.length;
110 #ifndef NO_OPENTYPE
111 const int availableGlyphs = item->num_glyphs;
112 #endif
113 HB_Bool haveGlyphs;
114 HB_STACKARRAY(HB_UChar16, reordered, len + 4);
115
116 if (item->num_glyphs < item->item.length + 4) {
117 item->num_glyphs = item->item.length + 4;
118 HB_FREE_STACKARRAY(reordered);
119 return FALSE;
120 }
121
122 if (invalid) {
123 *reordered = 0x25cc;
124 memcpy(reordered+1, str, len*sizeof(HB_UChar16));
125 len++;
126 str = reordered;
127 }
128
129 haveGlyphs = item->font->klass->convertStringToGlyphIndices(item->font,
130 str, len,
131 item->glyphs, &item->num_glyphs,
132 item->item.bidiLevel % 2);
133
134 HB_FREE_STACKARRAY(reordered);
135
136 if (!haveGlyphs)
137 return FALSE;
138
139 for (i = 0; i < item->item.length; i++) {
140 item->attributes[i].mark = FALSE;
141 item->attributes[i].clusterStart = FALSE;
142 item->attributes[i].justification = 0;
143 item->attributes[i].zeroWidth = FALSE;
144 /* IDEBUG(" %d: %4x", i, str[i]); */
145 }
146
147 /* now we have the syllable in the right order, and can start running it through open type. */
148
149 #ifndef NO_OPENTYPE
150 if (openType) {
151 HB_OpenTypeShape(item, /*properties*/0);
152 if (!HB_OpenTypePosition(item, availableGlyphs, /*doLogClusters*/FALSE))
153 return FALSE;
154 } else {
155 HB_HeuristicPosition(item);
156 }
157 #endif
158
159 item->attributes[0].clusterStart = TRUE;
160 return TRUE;
161 }
162
163
tibetan_nextSyllableBoundary(const HB_UChar16 * s,int start,int end,HB_Bool * invalid)164 static int tibetan_nextSyllableBoundary(const HB_UChar16 *s, int start, int end, HB_Bool *invalid)
165 {
166 const HB_UChar16 *uc = s + start;
167
168 int pos = 0;
169 TibetanForm state = tibetan_form(*uc);
170
171 /* qDebug("state[%d]=%d (uc=%4x)", pos, state, uc[pos]);*/
172 pos++;
173
174 if (state != TibetanHeadConsonant) {
175 if (state != TibetanOther)
176 *invalid = TRUE;
177 goto finish;
178 }
179
180 while (pos < end - start) {
181 TibetanForm newState = tibetan_form(uc[pos]);
182 switch(newState) {
183 case TibetanSubjoinedConsonant:
184 case TibetanSubjoinedVowel:
185 if (state != TibetanHeadConsonant &&
186 state != TibetanSubjoinedConsonant)
187 goto finish;
188 state = newState;
189 break;
190 case TibetanVowel:
191 if (state != TibetanHeadConsonant &&
192 state != TibetanSubjoinedConsonant &&
193 state != TibetanSubjoinedVowel)
194 goto finish;
195 break;
196 case TibetanOther:
197 case TibetanHeadConsonant:
198 goto finish;
199 }
200 pos++;
201 }
202
203 finish:
204 *invalid = FALSE;
205 return start+pos;
206 }
207
HB_TibetanShape(HB_ShaperItem * item)208 HB_Bool HB_TibetanShape(HB_ShaperItem *item)
209 {
210
211 HB_Bool openType = FALSE;
212 unsigned short *logClusters = item->log_clusters;
213
214 HB_ShaperItem syllable = *item;
215 int first_glyph = 0;
216
217 int sstart = item->item.pos;
218 int end = sstart + item->item.length;
219
220 assert(item->item.script == HB_Script_Tibetan);
221
222 #ifndef NO_OPENTYPE
223 openType = HB_SelectScript(item, tibetan_features);
224 #endif
225
226 while (sstart < end) {
227 HB_Bool invalid;
228 int i;
229 int send = tibetan_nextSyllableBoundary(item->string, sstart, end, &invalid);
230 /* IDEBUG("syllable from %d, length %d, invalid=%s", sstart, send-sstart,
231 invalid ? "TRUE" : "FALSE"); */
232 syllable.item.pos = sstart;
233 syllable.item.length = send-sstart;
234 syllable.glyphs = item->glyphs + first_glyph;
235 syllable.attributes = item->attributes + first_glyph;
236 syllable.offsets = item->offsets + first_glyph;
237 syllable.advances = item->advances + first_glyph;
238 syllable.num_glyphs = item->num_glyphs - first_glyph;
239 if (!tibetan_shape_syllable(openType, &syllable, invalid)) {
240 item->num_glyphs += syllable.num_glyphs;
241 return FALSE;
242 }
243 /* fix logcluster array */
244 for (i = sstart; i < send; ++i)
245 logClusters[i-item->item.pos] = first_glyph;
246 sstart = send;
247 first_glyph += syllable.num_glyphs;
248 }
249 item->num_glyphs = first_glyph;
250 return TRUE;
251 }
252
HB_TibetanAttributes(HB_Script script,const HB_UChar16 * text,hb_uint32 from,hb_uint32 len,HB_CharAttributes * attributes)253 void HB_TibetanAttributes(HB_Script script, const HB_UChar16 *text, hb_uint32 from, hb_uint32 len, HB_CharAttributes *attributes)
254 {
255 int end = from + len;
256 const HB_UChar16 *uc = text + from;
257 hb_uint32 i = 0;
258 HB_UNUSED(script);
259 attributes += from;
260 while (i < len) {
261 HB_Bool invalid;
262 hb_uint32 boundary = tibetan_nextSyllableBoundary(text, from+i, end, &invalid) - from;
263
264 attributes[i].graphemeBoundary = TRUE;
265
266 if (boundary > len-1) boundary = len;
267 i++;
268 while (i < boundary) {
269 attributes[i].graphemeBoundary = FALSE;
270 ++uc;
271 ++i;
272 }
273 assert(i == boundary);
274 }
275 }
276
277
278