1/*
2 * Copyright © 2011,2012,2014 Google, Inc.
3 *
4 * This is part of HarfBuzz, a text shaping 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 * Google Author(s): Behdad Esfahbod
25 */
26
27#ifndef HB_UTF_HH
28#define HB_UTF_HH
29
30#include "hb.hh"
31
32#include "hb-open-type.hh"
33
34
35struct hb_utf8_t
36{
37 typedef uint8_t codepoint_t;
38
39 static const codepoint_t *
40 next (const codepoint_t *text,
41 const codepoint_t *end,
42 hb_codepoint_t *unicode,
43 hb_codepoint_t replacement)
44 {
45 /* Written to only accept well-formed sequences.
46 * Based on ideas from ICU's U8_NEXT.
47 * Generates one "replacement" for each ill-formed byte. */
48
49 hb_codepoint_t c = *text++;
50
51 if (c > 0x7Fu)
52 {
53 if (hb_in_range<hb_codepoint_t> (c, 0xC2u, 0xDFu)) /* Two-byte */
54 {
55 unsigned int t1;
56 if (likely (text < end &&
57 (t1 = text[0] - 0x80u) <= 0x3Fu))
58 {
59 c = ((c&0x1Fu)<<6) | t1;
60 text++;
61 }
62 else
63 goto error;
64 }
65 else if (hb_in_range<hb_codepoint_t> (c, 0xE0u, 0xEFu)) /* Three-byte */
66 {
67 unsigned int t1, t2;
68 if (likely (1 < end - text &&
69 (t1 = text[0] - 0x80u) <= 0x3Fu &&
70 (t2 = text[1] - 0x80u) <= 0x3Fu))
71 {
72 c = ((c&0xFu)<<12) | (t1<<6) | t2;
73 if (unlikely (c < 0x0800u || hb_in_range<hb_codepoint_t> (c, 0xD800u, 0xDFFFu)))
74 goto error;
75 text += 2;
76 }
77 else
78 goto error;
79 }
80 else if (hb_in_range<hb_codepoint_t> (c, 0xF0u, 0xF4u)) /* Four-byte */
81 {
82 unsigned int t1, t2, t3;
83 if (likely (2 < end - text &&
84 (t1 = text[0] - 0x80u) <= 0x3Fu &&
85 (t2 = text[1] - 0x80u) <= 0x3Fu &&
86 (t3 = text[2] - 0x80u) <= 0x3Fu))
87 {
88 c = ((c&0x7u)<<18) | (t1<<12) | (t2<<6) | t3;
89 if (unlikely (!hb_in_range<hb_codepoint_t> (c, 0x10000u, 0x10FFFFu)))
90 goto error;
91 text += 3;
92 }
93 else
94 goto error;
95 }
96 else
97 goto error;
98 }
99
100 *unicode = c;
101 return text;
102
103 error:
104 *unicode = replacement;
105 return text;
106 }
107
108 static const codepoint_t *
109 prev (const codepoint_t *text,
110 const codepoint_t *start,
111 hb_codepoint_t *unicode,
112 hb_codepoint_t replacement)
113 {
114 const codepoint_t *end = text--;
115 while (start < text && (*text & 0xc0) == 0x80 && end - text < 4)
116 text--;
117
118 if (likely (next (text, end, unicode, replacement) == end))
119 return text;
120
121 *unicode = replacement;
122 return end - 1;
123 }
124
125 static unsigned int
126 strlen (const codepoint_t *text)
127 { return ::strlen ((const char *) text); }
128
129 static unsigned int
130 encode_len (hb_codepoint_t unicode)
131 {
132 if (unicode < 0x0080u) return 1;
133 if (unicode < 0x0800u) return 2;
134 if (unicode < 0x10000u) return 3;
135 if (unicode < 0x110000u) return 4;
136 return 3;
137 }
138
139 static codepoint_t *
140 encode (codepoint_t *text,
141 const codepoint_t *end,
142 hb_codepoint_t unicode)
143 {
144 if (unlikely (unicode >= 0xD800u && (unicode <= 0xDFFFu || unicode > 0x10FFFFu)))
145 unicode = 0xFFFDu;
146 if (unicode < 0x0080u)
147 *text++ = unicode;
148 else if (unicode < 0x0800u)
149 {
150 if (end - text >= 2)
151 {
152 *text++ = 0xC0u + (0x1Fu & (unicode >> 6));
153 *text++ = 0x80u + (0x3Fu & (unicode ));
154 }
155 }
156 else if (unicode < 0x10000u)
157 {
158 if (end - text >= 3)
159 {
160 *text++ = 0xE0u + (0x0Fu & (unicode >> 12));
161 *text++ = 0x80u + (0x3Fu & (unicode >> 6));
162 *text++ = 0x80u + (0x3Fu & (unicode ));
163 }
164 }
165 else
166 {
167 if (end - text >= 4)
168 {
169 *text++ = 0xF0u + (0x07u & (unicode >> 18));
170 *text++ = 0x80u + (0x3Fu & (unicode >> 12));
171 *text++ = 0x80u + (0x3Fu & (unicode >> 6));
172 *text++ = 0x80u + (0x3Fu & (unicode ));
173 }
174 }
175 return text;
176 }
177};
178
179
180template <typename TCodepoint>
181struct hb_utf16_xe_t
182{
183 static_assert (sizeof (TCodepoint) == 2, "");
184 typedef TCodepoint codepoint_t;
185
186 static const codepoint_t *
187 next (const codepoint_t *text,
188 const codepoint_t *end,
189 hb_codepoint_t *unicode,
190 hb_codepoint_t replacement)
191 {
192 hb_codepoint_t c = *text++;
193
194 if (likely (!hb_in_range<hb_codepoint_t> (c, 0xD800u, 0xDFFFu)))
195 {
196 *unicode = c;
197 return text;
198 }
199
200 if (likely (c <= 0xDBFFu && text < end))
201 {
202 /* High-surrogate in c */
203 hb_codepoint_t l = *text;
204 if (likely (hb_in_range<hb_codepoint_t> (l, 0xDC00u, 0xDFFFu)))
205 {
206 /* Low-surrogate in l */
207 *unicode = (c << 10) + l - ((0xD800u << 10) - 0x10000u + 0xDC00u);
208 text++;
209 return text;
210 }
211 }
212
213 /* Lonely / out-of-order surrogate. */
214 *unicode = replacement;
215 return text;
216 }
217
218 static const codepoint_t *
219 prev (const codepoint_t *text,
220 const codepoint_t *start,
221 hb_codepoint_t *unicode,
222 hb_codepoint_t replacement)
223 {
224 hb_codepoint_t c = *--text;
225
226 if (likely (!hb_in_range<hb_codepoint_t> (c, 0xD800u, 0xDFFFu)))
227 {
228 *unicode = c;
229 return text;
230 }
231
232 if (likely (c >= 0xDC00u && start < text))
233 {
234 /* Low-surrogate in c */
235 hb_codepoint_t h = text[-1];
236 if (likely (hb_in_range<hb_codepoint_t> (h, 0xD800u, 0xDBFFu)))
237 {
238 /* High-surrogate in h */
239 *unicode = (h << 10) + c - ((0xD800u << 10) - 0x10000u + 0xDC00u);
240 text--;
241 return text;
242 }
243 }
244
245 /* Lonely / out-of-order surrogate. */
246 *unicode = replacement;
247 return text;
248 }
249
250
251 static unsigned int
252 strlen (const codepoint_t *text)
253 {
254 unsigned int l = 0;
255 while (*text++) l++;
256 return l;
257 }
258
259 static unsigned int
260 encode_len (hb_codepoint_t unicode)
261 {
262 return unicode < 0x10000 ? 1 : 2;
263 }
264
265 static codepoint_t *
266 encode (codepoint_t *text,
267 const codepoint_t *end,
268 hb_codepoint_t unicode)
269 {
270 if (unlikely (unicode >= 0xD800u && (unicode <= 0xDFFFu || unicode > 0x10FFFFu)))
271 unicode = 0xFFFDu;
272 if (unicode < 0x10000u)
273 *text++ = unicode;
274 else if (end - text >= 2)
275 {
276 unicode -= 0x10000u;
277 *text++ = 0xD800u + (unicode >> 10);
278 *text++ = 0xDC00u + (unicode & 0x03FFu);
279 }
280 return text;
281 }
282};
283
284typedef hb_utf16_xe_t<uint16_t> hb_utf16_t;
285typedef hb_utf16_xe_t<OT::HBUINT16> hb_utf16_be_t;
286
287
288template <typename TCodepoint, bool validate=true>
289struct hb_utf32_xe_t
290{
291 static_assert (sizeof (TCodepoint) == 4, "");
292 typedef TCodepoint codepoint_t;
293
294 static const TCodepoint *
295 next (const TCodepoint *text,
296 const TCodepoint *end HB_UNUSED,
297 hb_codepoint_t *unicode,
298 hb_codepoint_t replacement)
299 {
300 hb_codepoint_t c = *unicode = *text++;
301 if (validate && unlikely (c >= 0xD800u && (c <= 0xDFFFu || c > 0x10FFFFu)))
302 *unicode = replacement;
303 return text;
304 }
305
306 static const TCodepoint *
307 prev (const TCodepoint *text,
308 const TCodepoint *start HB_UNUSED,
309 hb_codepoint_t *unicode,
310 hb_codepoint_t replacement)
311 {
312 hb_codepoint_t c = *unicode = *--text;
313 if (validate && unlikely (c >= 0xD800u && (c <= 0xDFFFu || c > 0x10FFFFu)))
314 *unicode = replacement;
315 return text;
316 }
317
318 static unsigned int
319 strlen (const TCodepoint *text)
320 {
321 unsigned int l = 0;
322 while (*text++) l++;
323 return l;
324 }
325
326 static unsigned int
327 encode_len (hb_codepoint_t unicode HB_UNUSED)
328 {
329 return 1;
330 }
331
332 static codepoint_t *
333 encode (codepoint_t *text,
334 const codepoint_t *end HB_UNUSED,
335 hb_codepoint_t unicode)
336 {
337 if (validate && unlikely (unicode >= 0xD800u && (unicode <= 0xDFFFu || unicode > 0x10FFFFu)))
338 unicode = 0xFFFDu;
339 *text++ = unicode;
340 return text;
341 }
342};
343
344typedef hb_utf32_xe_t<uint32_t> hb_utf32_t;
345typedef hb_utf32_xe_t<uint32_t, false> hb_utf32_novalidate_t;
346
347
348struct hb_latin1_t
349{
350 typedef uint8_t codepoint_t;
351
352 static const codepoint_t *
353 next (const codepoint_t *text,
354 const codepoint_t *end HB_UNUSED,
355 hb_codepoint_t *unicode,
356 hb_codepoint_t replacement HB_UNUSED)
357 {
358 *unicode = *text++;
359 return text;
360 }
361
362 static const codepoint_t *
363 prev (const codepoint_t *text,
364 const codepoint_t *start HB_UNUSED,
365 hb_codepoint_t *unicode,
366 hb_codepoint_t replacement HB_UNUSED)
367 {
368 *unicode = *--text;
369 return text;
370 }
371
372 static unsigned int
373 strlen (const codepoint_t *text)
374 {
375 unsigned int l = 0;
376 while (*text++) l++;
377 return l;
378 }
379
380 static unsigned int
381 encode_len (hb_codepoint_t unicode HB_UNUSED)
382 {
383 return 1;
384 }
385
386 static codepoint_t *
387 encode (codepoint_t *text,
388 const codepoint_t *end HB_UNUSED,
389 hb_codepoint_t unicode)
390 {
391 if (unlikely (unicode >= 0x0100u))
392 unicode = '?';
393 *text++ = unicode;
394 return text;
395 }
396};
397
398
399struct hb_ascii_t
400{
401 typedef uint8_t codepoint_t;
402
403 static const codepoint_t *
404 next (const codepoint_t *text,
405 const codepoint_t *end HB_UNUSED,
406 hb_codepoint_t *unicode,
407 hb_codepoint_t replacement HB_UNUSED)
408 {
409 *unicode = *text++;
410 if (*unicode >= 0x0080u)
411 *unicode = replacement;
412 return text;
413 }
414
415 static const codepoint_t *
416 prev (const codepoint_t *text,
417 const codepoint_t *start HB_UNUSED,
418 hb_codepoint_t *unicode,
419 hb_codepoint_t replacement)
420 {
421 *unicode = *--text;
422 if (*unicode >= 0x0080u)
423 *unicode = replacement;
424 return text;
425 }
426
427 static unsigned int
428 strlen (const codepoint_t *text)
429 {
430 unsigned int l = 0;
431 while (*text++) l++;
432 return l;
433 }
434
435 static unsigned int
436 encode_len (hb_codepoint_t unicode HB_UNUSED)
437 {
438 return 1;
439 }
440
441 static codepoint_t *
442 encode (codepoint_t *text,
443 const codepoint_t *end HB_UNUSED,
444 hb_codepoint_t unicode)
445 {
446 if (unlikely (unicode >= 0x0080u))
447 unicode = '?';
448 *text++ = unicode;
449 return text;
450 }
451};
452
453#endif /* HB_UTF_HH */
454