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-rw-r--r--gfx/graphite2/src/inc/UtfCodec.h251
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diff --git a/gfx/graphite2/src/inc/UtfCodec.h b/gfx/graphite2/src/inc/UtfCodec.h
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+/* GRAPHITE2 LICENSING
+
+ Copyright 2011, SIL International
+ All rights reserved.
+
+ This library is free software; you can redistribute it and/or modify
+ it under the terms of the GNU Lesser General Public License as published
+ by the Free Software Foundation; either version 2.1 of License, or
+ (at your option) any later version.
+
+ This program is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ Lesser General Public License for more details.
+
+ You should also have received a copy of the GNU Lesser General Public
+ License along with this library in the file named "LICENSE".
+ If not, write to the Free Software Foundation, 51 Franklin Street,
+ Suite 500, Boston, MA 02110-1335, USA or visit their web page on the
+ internet at http://www.fsf.org/licenses/lgpl.html.
+
+Alternatively, the contents of this file may be used under the terms of the
+Mozilla Public License (http://mozilla.org/MPL) or the GNU General Public
+License, as published by the Free Software Foundation, either version 2
+of the License or (at your option) any later version.
+*/
+#pragma once
+
+#include <cstdlib>
+#include "inc/Main.h"
+
+namespace graphite2 {
+
+typedef uint32 uchar_t;
+
+template <int N>
+struct _utf_codec
+{
+ typedef uchar_t codeunit_t;
+
+ static void put(codeunit_t * cp, const uchar_t , int8 & len) throw();
+ static uchar_t get(const codeunit_t * cp, int8 & len) throw();
+ static bool validate(const codeunit_t * s, const codeunit_t * const e) throw();
+};
+
+
+template <>
+struct _utf_codec<32>
+{
+private:
+ static const uchar_t limit = 0x110000;
+public:
+ typedef uint32 codeunit_t;
+
+ inline
+ static void put(codeunit_t * cp, const uchar_t usv, int8 & l) throw()
+ {
+ *cp = usv; l = 1;
+ }
+
+ inline
+ static uchar_t get(const codeunit_t * cp, int8 & l) throw()
+ {
+ if (cp[0] < limit) { l = 1; return cp[0]; }
+ else { l = -1; return 0xFFFD; }
+ }
+
+ inline
+ static bool validate(const codeunit_t * s, const codeunit_t * const e) throw()
+ {
+ return s <= e;
+ }
+};
+
+
+template <>
+struct _utf_codec<16>
+{
+private:
+ static const int32 lead_offset = 0xD800 - (0x10000 >> 10);
+ static const int32 surrogate_offset = 0x10000 - (0xD800 << 10) - 0xDC00;
+public:
+ typedef uint16 codeunit_t;
+
+ inline
+ static void put(codeunit_t * cp, const uchar_t usv, int8 & l) throw()
+ {
+ if (usv < 0x10000) { l = 1; cp[0] = codeunit_t(usv); }
+ else
+ {
+ cp[0] = codeunit_t(lead_offset + (usv >> 10));
+ cp[1] = codeunit_t(0xDC00 + (usv & 0x3FF));
+ l = 2;
+ }
+ }
+
+ inline
+ static uchar_t get(const codeunit_t * cp, int8 & l) throw()
+ {
+ const uint32 uh = cp[0];
+ l = 1;
+
+ if (uh < 0xD800|| uh > 0xDFFF) { return uh; }
+ if (uh > 0xDBFF) { l = -1; return 0xFFFD; }
+ const uint32 ul = cp[1];
+ if (ul < 0xDC00 || ul > 0xDFFF) { l = -1; return 0xFFFD; }
+ ++l;
+ return (uh<<10) + ul + surrogate_offset;
+ }
+
+ inline
+ static bool validate(const codeunit_t * s, const codeunit_t * const e) throw()
+ {
+ const ptrdiff_t n = e-s;
+ if (n <= 0) return n == 0;
+ const uint32 u = *(e-1); // Get the last codepoint
+ return (u < 0xD800 || u > 0xDBFF);
+ }
+};
+
+
+template <>
+struct _utf_codec<8>
+{
+private:
+ static const int8 sz_lut[16];
+ static const byte mask_lut[5];
+ static const uchar_t limit = 0x110000;
+
+public:
+ typedef uint8 codeunit_t;
+
+ inline
+ static void put(codeunit_t * cp, const uchar_t usv, int8 & l) throw()
+ {
+ if (usv < 0x80) {l = 1; cp[0] = usv; return; }
+ if (usv < 0x0800) {l = 2; cp[0] = 0xC0 + (usv >> 6); cp[1] = 0x80 + (usv & 0x3F); return; }
+ if (usv < 0x10000) {l = 3; cp[0] = 0xE0 + (usv >> 12); cp[1] = 0x80 + ((usv >> 6) & 0x3F); cp[2] = 0x80 + (usv & 0x3F); return; }
+ else {l = 4; cp[0] = 0xF0 + (usv >> 18); cp[1] = 0x80 + ((usv >> 12) & 0x3F); cp[2] = 0x80 + ((usv >> 6) & 0x3F); cp[3] = 0x80 + (usv & 0x3F); return; }
+ }
+
+ inline
+ static uchar_t get(const codeunit_t * cp, int8 & l) throw()
+ {
+ const int8 seq_sz = sz_lut[*cp >> 4];
+ uchar_t u = *cp & mask_lut[seq_sz];
+ l = 1;
+ bool toolong = false;
+
+ switch(seq_sz) {
+ case 4: u <<= 6; u |= *++cp & 0x3F; if (*cp >> 6 != 2) break; ++l; toolong = (u < 0x10); GR_FALLTHROUGH;
+ // no break
+ case 3: u <<= 6; u |= *++cp & 0x3F; if (*cp >> 6 != 2) break; ++l; toolong |= (u < 0x20); GR_FALLTHROUGH;
+ // no break
+ case 2: u <<= 6; u |= *++cp & 0x3F; if (*cp >> 6 != 2) break; ++l; toolong |= (u < 0x80); GR_FALLTHROUGH;
+ // no break
+ case 1: break;
+ case 0: l = -1; return 0xFFFD;
+ }
+
+ if (l != seq_sz || toolong || u >= limit)
+ {
+ l = -l;
+ return 0xFFFD;
+ }
+ return u;
+ }
+
+ inline
+ static bool validate(const codeunit_t * s, const codeunit_t * const e) throw()
+ {
+ const ptrdiff_t n = e-s;
+ if (n <= 0) return n == 0;
+ s += (n-1);
+ if (*s < 0x80) return true;
+ if (*s >= 0xC0) return false;
+ if (n == 1) return true;
+ if (*--s < 0x80) return true;
+ if (*s >= 0xE0) return false;
+ if (n == 2 || *s >= 0xC0) return true;
+ if (*--s < 0x80) return true;
+ if (*s >= 0xF0) return false;
+ return true;
+ }
+
+};
+
+
+template <typename C>
+class _utf_iterator
+{
+ typedef _utf_codec<sizeof(C)*8> codec;
+
+ C * cp;
+ mutable int8 sl;
+
+public:
+ typedef C codeunit_type;
+ typedef uchar_t value_type;
+ typedef uchar_t * pointer;
+
+ class reference
+ {
+ const _utf_iterator & _i;
+
+ reference(const _utf_iterator & i): _i(i) {}
+ public:
+ operator value_type () const throw () { return codec::get(_i.cp, _i.sl); }
+ reference & operator = (const value_type usv) throw() { codec::put(_i.cp, usv, _i.sl); return *this; }
+
+ friend class _utf_iterator;
+ };
+
+
+ _utf_iterator(const void * us=0) : cp(reinterpret_cast<C *>(const_cast<void *>(us))), sl(1) { }
+
+ _utf_iterator & operator ++ () { cp += abs(sl); return *this; }
+ _utf_iterator operator ++ (int) { _utf_iterator tmp(*this); operator++(); return tmp; }
+
+ bool operator == (const _utf_iterator & rhs) const throw() { return cp >= rhs.cp; }
+ bool operator != (const _utf_iterator & rhs) const throw() { return !operator==(rhs); }
+
+ reference operator * () const throw() { return *this; }
+ pointer operator ->() const throw() { return &operator *(); }
+
+ operator codeunit_type * () const throw() { return cp; }
+
+ bool error() const throw() { return sl < 1; }
+ bool validate(const _utf_iterator & e) { return codec::validate(cp, e.cp); }
+};
+
+template <typename C>
+struct utf
+{
+ typedef typename _utf_codec<sizeof(C)*8>::codeunit_t codeunit_t;
+
+ typedef _utf_iterator<C> iterator;
+ typedef _utf_iterator<const C> const_iterator;
+
+ inline
+ static bool validate(codeunit_t * s, codeunit_t * e) throw() {
+ return _utf_codec<sizeof(C)*8>::validate(s,e);
+ }
+};
+
+
+typedef utf<uint32> utf32;
+typedef utf<uint16> utf16;
+typedef utf<uint8> utf8;
+
+} // namespace graphite2
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