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+/*
+ * 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 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 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 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 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 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++;
+ 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;
+ }
+};
+
+#endif /* HB_UTF_HH */
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