2 * Copyright © 2011,2012,2014 Google, Inc.
4 * This is part of HarfBuzz, a text shaping library.
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.
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
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.
24 * Google Author(s): Behdad Esfahbod
27 #ifndef HB_UTF_PRIVATE_HH
28 #define HB_UTF_PRIVATE_HH
30 #include "hb-private.hh"
35 typedef uint8_t codepoint_t;
37 static inline const uint8_t *
38 next (const uint8_t *text,
40 hb_codepoint_t *unicode,
41 hb_codepoint_t replacement)
43 /* Written to only accept well-formed sequences.
44 * Based on ideas from ICU's U8_NEXT.
45 * Generates one "replacement" for each ill-formed byte. */
47 hb_codepoint_t c = *text++;
51 if (hb_in_range (c, 0xC2u, 0xDFu)) /* Two-byte */
54 if (likely (text < end &&
55 (t1 = text[0] - 0x80u) <= 0x3Fu))
57 c = ((c&0x1Fu)<<6) | t1;
63 else if (hb_in_range (c, 0xE0u, 0xEFu)) /* Three-byte */
66 if (likely (1 < end - text &&
67 (t1 = text[0] - 0x80u) <= 0x3Fu &&
68 (t2 = text[1] - 0x80u) <= 0x3Fu))
70 c = ((c&0xFu)<<12) | (t1<<6) | t2;
71 if (unlikely (c < 0x0800u || hb_in_range (c, 0xD800u, 0xDFFFu)))
78 else if (hb_in_range (c, 0xF0u, 0xF4u)) /* Four-byte */
80 unsigned int t1, t2, t3;
81 if (likely (2 < end - text &&
82 (t1 = text[0] - 0x80u) <= 0x3Fu &&
83 (t2 = text[1] - 0x80u) <= 0x3Fu &&
84 (t3 = text[2] - 0x80u) <= 0x3Fu))
86 c = ((c&0x7u)<<18) | (t1<<12) | (t2<<6) | t3;
87 if (unlikely (!hb_in_range (c, 0x10000u, 0x10FFFFu)))
102 *unicode = replacement;
106 static inline const uint8_t *
107 prev (const uint8_t *text,
108 const uint8_t *start,
109 hb_codepoint_t *unicode,
110 hb_codepoint_t replacement)
112 const uint8_t *end = text--;
113 while (start < text && (*text & 0xc0) == 0x80 && end - text < 4)
116 if (likely (next (text, end, unicode, replacement) == end))
119 *unicode = replacement;
123 static inline unsigned int
124 strlen (const uint8_t *text)
126 return ::strlen ((const char *) text);
133 typedef uint16_t codepoint_t;
135 static inline const uint16_t *
136 next (const uint16_t *text,
138 hb_codepoint_t *unicode,
139 hb_codepoint_t replacement)
141 hb_codepoint_t c = *text++;
143 if (likely (!hb_in_range (c, 0xD800u, 0xDFFFu)))
149 if (likely (hb_in_range (c, 0xD800u, 0xDBFFu)))
151 /* High-surrogate in c */
153 if (text < end && ((l = *text), likely (hb_in_range (l, 0xDC00u, 0xDFFFu))))
155 /* Low-surrogate in l */
156 *unicode = (c << 10) + l - ((0xD800u << 10) - 0x10000u + 0xDC00u);
162 /* Lonely / out-of-order surrogate. */
163 *unicode = replacement;
167 static inline const uint16_t *
168 prev (const uint16_t *text,
169 const uint16_t *start,
170 hb_codepoint_t *unicode,
171 hb_codepoint_t replacement)
173 const uint16_t *end = text--;
174 hb_codepoint_t c = *text;
176 if (likely (!hb_in_range (c, 0xD800u, 0xDFFFu)))
182 if (likely (start < text && hb_in_range (c, 0xDC00u, 0xDFFFu)))
185 if (likely (next (text, end, unicode, replacement) == end))
188 *unicode = replacement;
193 static inline unsigned int
194 strlen (const uint16_t *text)
203 template <bool validate=true>
206 typedef uint32_t codepoint_t;
208 static inline const uint32_t *
209 next (const uint32_t *text,
210 const uint32_t *end HB_UNUSED,
211 hb_codepoint_t *unicode,
212 hb_codepoint_t replacement)
214 hb_codepoint_t c = *text++;
215 if (validate && unlikely (c > 0x10FFFFu || hb_in_range (c, 0xD800u, 0xDFFFu)))
221 *unicode = replacement;
225 static inline const uint32_t *
226 prev (const uint32_t *text,
227 const uint32_t *start HB_UNUSED,
228 hb_codepoint_t *unicode,
229 hb_codepoint_t replacement)
231 next (text - 1, text, unicode, replacement);
235 static inline unsigned int
236 strlen (const uint32_t *text)
247 typedef uint8_t codepoint_t;
249 static inline const uint8_t *
250 next (const uint8_t *text,
251 const uint8_t *end HB_UNUSED,
252 hb_codepoint_t *unicode,
253 hb_codepoint_t replacement HB_UNUSED)
259 static inline const uint8_t *
260 prev (const uint8_t *text,
261 const uint8_t *start HB_UNUSED,
262 hb_codepoint_t *unicode,
263 hb_codepoint_t replacement)
269 static inline unsigned int
270 strlen (const uint8_t *text)
278 #endif /* HB_UTF_PRIVATE_HH */