Edit
kc3-lang/harfbuzz/src/hb-utf.hh
Behdad Esfahbod
- src/hb-utf.hh
-
/* * Copyright © 2011,2012,2014 Google, Inc. * * This is part of HarfBuzz, a text shaping 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. * * Google Author(s): Behdad Esfahbod */ #ifndef HB_UTF_HH #define HB_UTF_HH #include "hb.hh" struct hb_utf8_t { typedef uint8_t codepoint_t; static inline const uint8_t * next (const uint8_t *text, const uint8_t *end, hb_codepoint_t *unicode, hb_codepoint_t replacement) { /* Written to only accept well-formed sequences. * Based on ideas from ICU's U8_NEXT. * Generates one "replacement" for each ill-formed byte. */ hb_codepoint_t c = *text++; if (c > 0x7Fu) { if (hb_in_range<hb_codepoint_t> (c, 0xC2u, 0xDFu)) /* Two-byte */ { unsigned int t1; if (likely (text < end && (t1 = text[0] - 0x80u) <= 0x3Fu)) { c = ((c&0x1Fu)<<6) | t1; text++; } else goto error; } else if (hb_in_range<hb_codepoint_t> (c, 0xE0u, 0xEFu)) /* Three-byte */ { unsigned int t1, t2; if (likely (1 < end - text && (t1 = text[0] - 0x80u) <= 0x3Fu && (t2 = text[1] - 0x80u) <= 0x3Fu)) { c = ((c&0xFu)<<12) | (t1<<6) | t2; if (unlikely (c < 0x0800u || hb_in_range<hb_codepoint_t> (c, 0xD800u, 0xDFFFu))) goto error; text += 2; } else goto error; } else if (hb_in_range<hb_codepoint_t> (c, 0xF0u, 0xF4u)) /* Four-byte */ { unsigned int t1, t2, t3; if (likely (2 < end - text && (t1 = text[0] - 0x80u) <= 0x3Fu && (t2 = text[1] - 0x80u) <= 0x3Fu && (t3 = text[2] - 0x80u) <= 0x3Fu)) { c = ((c&0x7u)<<18) | (t1<<12) | (t2<<6) | t3; if (unlikely (!hb_in_range<hb_codepoint_t> (c, 0x10000u, 0x10FFFFu))) goto error; text += 3; } else goto error; } else goto error; } *unicode = c; return text; error: *unicode = replacement; return text; } static inline const uint8_t * prev (const uint8_t *text, const uint8_t *start, hb_codepoint_t *unicode, hb_codepoint_t replacement) { const uint8_t *end = text--; while (start < text && (*text & 0xc0) == 0x80 && end - text < 4) text--; if (likely (next (text, end, unicode, replacement) == end)) return text; *unicode = replacement; return end - 1; } static inline unsigned int strlen (const uint8_t *text) { return ::strlen ((const char *) text); } }; struct hb_utf16_t { typedef uint16_t codepoint_t; static inline const uint16_t * next (const uint16_t *text, const uint16_t *end, hb_codepoint_t *unicode, hb_codepoint_t replacement) { hb_codepoint_t c = *text++; if (likely (!hb_in_range<hb_codepoint_t> (c, 0xD800u, 0xDFFFu))) { *unicode = c; return text; } if (likely (c <= 0xDBFFu && text < end)) { /* High-surrogate in c */ hb_codepoint_t l = *text; if (likely (hb_in_range<hb_codepoint_t> (l, 0xDC00u, 0xDFFFu))) { /* Low-surrogate in l */ *unicode = (c << 10) + l - ((0xD800u << 10) - 0x10000u + 0xDC00u); text++; return text; } } /* Lonely / out-of-order surrogate. */ *unicode = replacement; return text; } static inline const uint16_t * prev (const uint16_t *text, const uint16_t *start, hb_codepoint_t *unicode, hb_codepoint_t replacement) { hb_codepoint_t c = *--text; if (likely (!hb_in_range<hb_codepoint_t> (c, 0xD800u, 0xDFFFu))) { *unicode = c; return text; } if (likely (c >= 0xDC00u && start < text)) { /* Low-surrogate in c */ hb_codepoint_t h = text[-1]; if (likely (hb_in_range<hb_codepoint_t> (h, 0xD800u, 0xDBFFu))) { /* High-surrogate in h */ *unicode = (h << 10) + c - ((0xD800u << 10) - 0x10000u + 0xDC00u); text--; return text; } } /* Lonely / out-of-order surrogate. */ *unicode = replacement; return text; } static inline unsigned int strlen (const uint16_t *text) { unsigned int l = 0; while (*text++) l++; return l; } }; template <bool validate=true> struct hb_utf32_t { typedef uint32_t codepoint_t; static inline const uint32_t * next (const uint32_t *text, const uint32_t *end HB_UNUSED, hb_codepoint_t *unicode, hb_codepoint_t replacement) { hb_codepoint_t c = *unicode = *text++; if (validate && unlikely (c >= 0xD800u && (c <= 0xDFFFu || c > 0x10FFFFu))) *unicode = replacement; return text; } static inline const uint32_t * prev (const uint32_t *text, const uint32_t *start HB_UNUSED, hb_codepoint_t *unicode, hb_codepoint_t replacement) { hb_codepoint_t c = *unicode = *--text; if (validate && unlikely (c >= 0xD800u && (c <= 0xDFFFu || c > 0x10FFFFu))) *unicode = replacement; return text; } static inline unsigned int strlen (const uint32_t *text) { unsigned int l = 0; while (*text++) l++; return l; } }; struct hb_latin1_t { typedef uint8_t codepoint_t; static inline const uint8_t * next (const uint8_t *text, const uint8_t *end HB_UNUSED, hb_codepoint_t *unicode, hb_codepoint_t replacement HB_UNUSED) { *unicode = *text++; return text; } static inline const uint8_t * prev (const uint8_t *text, const uint8_t *start HB_UNUSED, hb_codepoint_t *unicode, hb_codepoint_t replacement) { *unicode = *--text; return text; } static inline unsigned int strlen (const uint8_t *text) { unsigned int l = 0; while (*text++) l++; return l; } }; #endif /* HB_UTF_HH */