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Diffstat (limited to '')
-rw-r--r-- | gfx/harfbuzz/src/hb-utf.hh | 481 |
1 files changed, 481 insertions, 0 deletions
diff --git a/gfx/harfbuzz/src/hb-utf.hh b/gfx/harfbuzz/src/hb-utf.hh new file mode 100644 index 0000000000..1120bd1ccc --- /dev/null +++ b/gfx/harfbuzz/src/hb-utf.hh @@ -0,0 +1,481 @@ +/* + * 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" + +#include "hb-open-type.hh" + + +struct hb_utf8_t +{ + typedef uint8_t codepoint_t; + static constexpr unsigned max_len = 4; + + static const codepoint_t * + next (const codepoint_t *text, + const codepoint_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 const codepoint_t * + prev (const codepoint_t *text, + const codepoint_t *start, + hb_codepoint_t *unicode, + hb_codepoint_t replacement) + { + const codepoint_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 unsigned int + strlen (const codepoint_t *text) + { return ::strlen ((const char *) text); } + + static unsigned int + encode_len (hb_codepoint_t unicode) + { + if (unicode < 0x0080u) return 1; + if (unicode < 0x0800u) return 2; + if (unicode < 0x10000u) return 3; + if (unicode < 0x110000u) return 4; + return 3; + } + + static codepoint_t * + encode (codepoint_t *text, + const codepoint_t *end, + hb_codepoint_t unicode) + { + if (unlikely (unicode >= 0xD800u && (unicode <= 0xDFFFu || unicode > 0x10FFFFu))) + unicode = 0xFFFDu; + if (unicode < 0x0080u) + *text++ = unicode; + else if (unicode < 0x0800u) + { + if (end - text >= 2) + { + *text++ = 0xC0u + (0x1Fu & (unicode >> 6)); + *text++ = 0x80u + (0x3Fu & (unicode )); + } + } + else if (unicode < 0x10000u) + { + if (end - text >= 3) + { + *text++ = 0xE0u + (0x0Fu & (unicode >> 12)); + *text++ = 0x80u + (0x3Fu & (unicode >> 6)); + *text++ = 0x80u + (0x3Fu & (unicode )); + } + } + else + { + if (end - text >= 4) + { + *text++ = 0xF0u + (0x07u & (unicode >> 18)); + *text++ = 0x80u + (0x3Fu & (unicode >> 12)); + *text++ = 0x80u + (0x3Fu & (unicode >> 6)); + *text++ = 0x80u + (0x3Fu & (unicode )); + } + } + return text; + } +}; + + +template <typename TCodepoint> +struct hb_utf16_xe_t +{ + static_assert (sizeof (TCodepoint) == 2, ""); + typedef TCodepoint codepoint_t; + static constexpr unsigned max_len = 2; + + static const codepoint_t * + next (const codepoint_t *text, + const codepoint_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 const codepoint_t * + prev (const codepoint_t *text, + const codepoint_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 unsigned int + strlen (const codepoint_t *text) + { + unsigned int l = 0; + while (*text++) l++; + return l; + } + + static unsigned int + encode_len (hb_codepoint_t unicode) + { + return unicode < 0x10000 ? 1 : 2; + } + + static codepoint_t * + encode (codepoint_t *text, + const codepoint_t *end, + hb_codepoint_t unicode) + { + if (unlikely (unicode >= 0xD800u && (unicode <= 0xDFFFu || unicode > 0x10FFFFu))) + unicode = 0xFFFDu; + if (unicode < 0x10000u) + *text++ = unicode; + else if (end - text >= 2) + { + unicode -= 0x10000u; + *text++ = 0xD800u + (unicode >> 10); + *text++ = 0xDC00u + (unicode & 0x03FFu); + } + return text; + } +}; + +typedef hb_utf16_xe_t<uint16_t> hb_utf16_t; +typedef hb_utf16_xe_t<OT::HBUINT16> hb_utf16_be_t; + + +template <typename TCodepoint, bool validate=true> +struct hb_utf32_xe_t +{ + static_assert (sizeof (TCodepoint) == 4, ""); + typedef TCodepoint codepoint_t; + static constexpr unsigned max_len = 1; + + static const TCodepoint * + next (const TCodepoint *text, + const TCodepoint *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 const TCodepoint * + prev (const TCodepoint *text, + const TCodepoint *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 unsigned int + strlen (const TCodepoint *text) + { + unsigned int l = 0; + while (*text++) l++; + return l; + } + + static unsigned int + encode_len (hb_codepoint_t unicode HB_UNUSED) + { + return 1; + } + + static codepoint_t * + encode (codepoint_t *text, + const codepoint_t *end HB_UNUSED, + hb_codepoint_t unicode) + { + if (validate && unlikely (unicode >= 0xD800u && (unicode <= 0xDFFFu || unicode > 0x10FFFFu))) + unicode = 0xFFFDu; + *text++ = unicode; + return text; + } +}; + +typedef hb_utf32_xe_t<uint32_t> hb_utf32_t; +typedef hb_utf32_xe_t<uint32_t, false> hb_utf32_novalidate_t; + + +struct hb_latin1_t +{ + typedef uint8_t codepoint_t; + static constexpr unsigned max_len = 1; + + static const codepoint_t * + next (const codepoint_t *text, + const codepoint_t *end HB_UNUSED, + hb_codepoint_t *unicode, + hb_codepoint_t replacement HB_UNUSED) + { + *unicode = *text++; + return text; + } + + static const codepoint_t * + prev (const codepoint_t *text, + const codepoint_t *start HB_UNUSED, + hb_codepoint_t *unicode, + hb_codepoint_t replacement HB_UNUSED) + { + *unicode = *--text; + return text; + } + + static unsigned int + strlen (const codepoint_t *text) + { + unsigned int l = 0; + while (*text++) l++; + return l; + } + + static unsigned int + encode_len (hb_codepoint_t unicode HB_UNUSED) + { + return 1; + } + + static codepoint_t * + encode (codepoint_t *text, + const codepoint_t *end HB_UNUSED, + hb_codepoint_t unicode) + { + if (unlikely (unicode >= 0x0100u)) + unicode = '?'; + *text++ = unicode; + return text; + } +}; + + +struct hb_ascii_t +{ + typedef uint8_t codepoint_t; + static constexpr unsigned max_len = 1; + + static const codepoint_t * + next (const codepoint_t *text, + const codepoint_t *end HB_UNUSED, + hb_codepoint_t *unicode, + hb_codepoint_t replacement) + { + *unicode = *text++; + if (*unicode >= 0x0080u) + *unicode = replacement; + return text; + } + + static const codepoint_t * + prev (const codepoint_t *text, + const codepoint_t *start HB_UNUSED, + hb_codepoint_t *unicode, + hb_codepoint_t replacement) + { + *unicode = *--text; + if (*unicode >= 0x0080u) + *unicode = replacement; + return text; + } + + static unsigned int + strlen (const codepoint_t *text) + { + unsigned int l = 0; + while (*text++) l++; + return l; + } + + static unsigned int + encode_len (hb_codepoint_t unicode HB_UNUSED) + { + return 1; + } + + static codepoint_t * + encode (codepoint_t *text, + const codepoint_t *end HB_UNUSED, + hb_codepoint_t unicode) + { + if (unlikely (unicode >= 0x0080u)) + unicode = '?'; + *text++ = unicode; + return text; + } +}; + +template <typename utf_t> +static inline const typename utf_t::codepoint_t * +hb_utf_offset_to_pointer (const typename utf_t::codepoint_t *start, + signed offset) +{ + hb_codepoint_t unicode; + + while (offset-- > 0) + start = utf_t::next (start, + start + utf_t::max_len, + &unicode, + HB_BUFFER_REPLACEMENT_CODEPOINT_DEFAULT); + + while (offset++ < 0) + start = utf_t::prev (start, + start - utf_t::max_len, + &unicode, + HB_BUFFER_REPLACEMENT_CODEPOINT_DEFAULT); + + return start; +} + + +#endif /* HB_UTF_HH */ |