1 /*
2 * Copyright (C) 2008 Nokia Corporation and/or its subsidiary(-ies)
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 static const HB_OpenTypeFeature tibetan_features[] = {
96 { HB_MAKE_TAG('c', 'c', 'm', 'p'), CcmpProperty },
97 { HB_MAKE_TAG('a', 'b', 'v', 's'), AboveSubstProperty },
98 { HB_MAKE_TAG('b', 'l', 'w', 's'), BelowSubstProperty },
99 { HB_MAKE_TAG('c', 'a', 'l', 't'), CaltProperty },
100 {0, 0}
101 };
102
tibetan_shape_syllable(HB_Bool openType,HB_ShaperItem * item,HB_Bool invalid)103 static HB_Bool tibetan_shape_syllable(HB_Bool openType, HB_ShaperItem *item, HB_Bool invalid)
104 {
105 hb_uint32 i;
106 const HB_UChar16 *str = item->string + item->item.pos;
107 int len = item->item.length;
108 #ifndef NO_OPENTYPE
109 const int availableGlyphs = item->num_glyphs;
110 #endif
111 HB_Bool haveGlyphs;
112 HB_STACKARRAY(HB_UChar16, reordered, len + 4);
113
114 if (item->num_glyphs < item->item.length + 4) {
115 item->num_glyphs = item->item.length + 4;
116 return FALSE;
117 }
118
119 if (invalid) {
120 *reordered = 0x25cc;
121 memcpy(reordered+1, str, len*sizeof(HB_UChar16));
122 len++;
123 str = reordered;
124 }
125
126 haveGlyphs = item->font->klass->convertStringToGlyphIndices(item->font,
127 str, len,
128 item->glyphs, &item->num_glyphs,
129 item->item.bidiLevel % 2);
130
131 HB_FREE_STACKARRAY(reordered);
132
133 if (!haveGlyphs)
134 return FALSE;
135
136 for (i = 0; i < item->item.length; i++) {
137 item->attributes[i].mark = FALSE;
138 item->attributes[i].clusterStart = FALSE;
139 item->attributes[i].justification = 0;
140 item->attributes[i].zeroWidth = FALSE;
141 /* IDEBUG(" %d: %4x", i, str[i]); */
142 }
143
144 /* now we have the syllable in the right order, and can start running it through open type. */
145
146 #ifndef NO_OPENTYPE
147 if (openType) {
148 HB_OpenTypeShape(item, /*properties*/0);
149 if (!HB_OpenTypePosition(item, availableGlyphs, /*doLogClusters*/FALSE))
150 return FALSE;
151 } else {
152 HB_HeuristicPosition(item);
153 }
154 #endif
155
156 item->attributes[0].clusterStart = TRUE;
157 return TRUE;
158 }
159
160
tibetan_nextSyllableBoundary(const HB_UChar16 * s,int start,int end,HB_Bool * invalid)161 static int tibetan_nextSyllableBoundary(const HB_UChar16 *s, int start, int end, HB_Bool *invalid)
162 {
163 const HB_UChar16 *uc = s + start;
164
165 int pos = 0;
166 TibetanForm state = tibetan_form(*uc);
167
168 /* qDebug("state[%d]=%d (uc=%4x)", pos, state, uc[pos]);*/
169 pos++;
170
171 if (state != TibetanHeadConsonant) {
172 if (state != TibetanOther)
173 *invalid = TRUE;
174 goto finish;
175 }
176
177 while (pos < end - start) {
178 TibetanForm newState = tibetan_form(uc[pos]);
179 switch(newState) {
180 case TibetanSubjoinedConsonant:
181 case TibetanSubjoinedVowel:
182 if (state != TibetanHeadConsonant &&
183 state != TibetanSubjoinedConsonant)
184 goto finish;
185 state = newState;
186 break;
187 case TibetanVowel:
188 if (state != TibetanHeadConsonant &&
189 state != TibetanSubjoinedConsonant &&
190 state != TibetanSubjoinedVowel)
191 goto finish;
192 break;
193 case TibetanOther:
194 case TibetanHeadConsonant:
195 goto finish;
196 }
197 pos++;
198 }
199
200 finish:
201 *invalid = FALSE;
202 return start+pos;
203 }
204
HB_TibetanShape(HB_ShaperItem * item)205 HB_Bool HB_TibetanShape(HB_ShaperItem *item)
206 {
207
208 HB_Bool openType = FALSE;
209 unsigned short *logClusters = item->log_clusters;
210
211 HB_ShaperItem syllable = *item;
212 int first_glyph = 0;
213
214 int sstart = item->item.pos;
215 int end = sstart + item->item.length;
216
217 assert(item->item.script == HB_Script_Tibetan);
218
219 #ifndef QT_NO_OPENTYPE
220 openType = HB_SelectScript(item, tibetan_features);
221 #endif
222
223 while (sstart < end) {
224 HB_Bool invalid;
225 int i;
226 int send = tibetan_nextSyllableBoundary(item->string, sstart, end, &invalid);
227 /* IDEBUG("syllable from %d, length %d, invalid=%s", sstart, send-sstart,
228 invalid ? "TRUE" : "FALSE"); */
229 syllable.item.pos = sstart;
230 syllable.item.length = send-sstart;
231 syllable.glyphs = item->glyphs + first_glyph;
232 syllable.attributes = item->attributes + first_glyph;
233 syllable.offsets = item->offsets + first_glyph;
234 syllable.advances = item->advances + first_glyph;
235 syllable.num_glyphs = item->num_glyphs - first_glyph;
236 if (!tibetan_shape_syllable(openType, &syllable, invalid)) {
237 item->num_glyphs += syllable.num_glyphs;
238 return FALSE;
239 }
240 /* fix logcluster array */
241 for (i = sstart; i < send; ++i)
242 logClusters[i-item->item.pos] = first_glyph;
243 sstart = send;
244 first_glyph += syllable.num_glyphs;
245 }
246 item->num_glyphs = first_glyph;
247 return TRUE;
248 }
249
HB_TibetanAttributes(HB_Script script,const HB_UChar16 * text,hb_uint32 from,hb_uint32 len,HB_CharAttributes * attributes)250 void HB_TibetanAttributes(HB_Script script, const HB_UChar16 *text, hb_uint32 from, hb_uint32 len, HB_CharAttributes *attributes)
251 {
252 int end = from + len;
253 const HB_UChar16 *uc = text + from;
254 hb_uint32 i = 0;
255 HB_UNUSED(script);
256 attributes += from;
257 while (i < len) {
258 HB_Bool invalid;
259 hb_uint32 boundary = tibetan_nextSyllableBoundary(text, from+i, end, &invalid) - from;
260
261 attributes[i].charStop = TRUE;
262
263 if (boundary > len-1) boundary = len;
264 i++;
265 while (i < boundary) {
266 attributes[i].charStop = FALSE;
267 ++uc;
268 ++i;
269 }
270 assert(i == boundary);
271 }
272 }
273
274
275