gfx/graphite2/src/CmapCache.cpp

   1 /*  GRAPHITE2 LICENSING
   2
   3     Copyright 2010, SIL International
   4     All rights reserved.
   5
   6     This library is free software; you can redistribute it and/or modify
   7     it under the terms of the GNU Lesser General Public License as published
   8     by the Free Software Foundation; either version 2.1 of License, or
   9     (at your option) any later version.
  10
  11     This program is distributed in the hope that it will be useful,
  12     but WITHOUT ANY WARRANTY; without even the implied warranty of
  13     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14     Lesser General Public License for more details.
  15
  16     You should also have received a copy of the GNU Lesser General Public
  17     License along with this library in the file named "LICENSE".
  18     If not, write to the Free Software Foundation, 51 Franklin Street,
  19     Suite 500, Boston, MA 02110-1335, USA or visit their web page on the
  20     internet at http://www.fsf.org/licenses/lgpl.html.
  21
  22 Alternatively, the contents of this file may be used under the terms of the
  23 Mozilla Public License (http://mozilla.org/MPL) or the GNU General Public
  24 License, as published by the Free Software Foundation, either version 2
  25 of the License or (at your option) any later version.
  26 */
  27
  28 #include "inc/Main.h"
  29 #include "inc/CmapCache.h"
  30 #include "inc/Face.h"
  31 #include "inc/TtfTypes.h"
  32 #include "inc/TtfUtil.h"
  33
  34
  35 using namespace graphite2;
  36
  37 const void * bmp_subtable(const Face::Table & cmap)
  38 {
  39     const void * stbl;
  40     if (!cmap.size()) return 0;
  41     if (TtfUtil::CheckCmapSubtable4(stbl = TtfUtil::FindCmapSubtable(cmap, 3, 1, cmap.size()), cmap + cmap.size())
  42      || TtfUtil::CheckCmapSubtable4(stbl = TtfUtil::FindCmapSubtable(cmap, 0, 3, cmap.size()), cmap + cmap.size())
  43      || TtfUtil::CheckCmapSubtable4(stbl = TtfUtil::FindCmapSubtable(cmap, 0, 2, cmap.size()), cmap + cmap.size())
  44      || TtfUtil::CheckCmapSubtable4(stbl = TtfUtil::FindCmapSubtable(cmap, 0, 1, cmap.size()), cmap + cmap.size())
  45      || TtfUtil::CheckCmapSubtable4(stbl = TtfUtil::FindCmapSubtable(cmap, 0, 0, cmap.size()), cmap + cmap.size()))
  46         return stbl;
  47     return 0;
  48 }
  49
  50 const void * smp_subtable(const Face::Table & cmap)
  51 {
  52     const void * stbl;
  53     if (!cmap.size()) return 0;
  54     if (TtfUtil::CheckCmapSubtable12(stbl = TtfUtil::FindCmapSubtable(cmap, 3, 10, cmap.size()), cmap + cmap.size())
  55      || TtfUtil::CheckCmapSubtable12(stbl = TtfUtil::FindCmapSubtable(cmap, 0, 4, cmap.size()), cmap + cmap.size()))
  56         return stbl;
  57     return 0;
  58 }
  59
  60 template <unsigned int (*NextCodePoint)(const void *, unsigned int, int *),
  61           uint16 (*LookupCodePoint)(const void *, unsigned int, int)>
  62 bool cache_subtable(uint16 * blocks[], const void * cst, const unsigned int limit)
  63 {
  64     int rangeKey = 0;
  65     uint32          codePoint = NextCodePoint(cst, 0, &rangeKey),
  66                     prevCodePoint = 0;
  67     while (codePoint < limit)
  68     {
  69         unsigned int block = codePoint >> 8;
  70         if (!blocks[block])
  71         {
  72             blocks[block] = grzeroalloc<uint16>(0x100);
  73             if (!blocks[block])
  74                 return false;
  75         }
  76         blocks[block][codePoint & 0xFF] = LookupCodePoint(cst, codePoint, rangeKey);
  77         // prevent infinite loop
  78         if (codePoint <= prevCodePoint)
  79             codePoint = prevCodePoint + 1;
  80         prevCodePoint = codePoint;
  81         codePoint =  NextCodePoint(cst, codePoint, &rangeKey);
  82     }
  83     return true;
  84 }
  85
  86
  87 CachedCmap::CachedCmap(const Face & face)
  88 : m_isBmpOnly(true),
  89   m_blocks(0)
  90 {
  91     const Face::Table cmap(face, Tag::cmap);
  92     if (!cmap)  return;
  93
  94     const void * bmp_cmap = bmp_subtable(cmap);
  95     const void * smp_cmap = smp_subtable(cmap);
  96     m_isBmpOnly = !smp_cmap;
  97
  98     m_blocks = grzeroalloc<uint16 *>(m_isBmpOnly ? 0x100 : 0x1100);
  99     if (m_blocks && smp_cmap)
 100     {
 101         if (!cache_subtable<TtfUtil::CmapSubtable12NextCodepoint, TtfUtil::CmapSubtable12Lookup>(m_blocks, smp_cmap, 0x10FFFF))
 102             return;
 103     }
 104
 105     if (m_blocks && bmp_cmap)
 106     {
 107         if (!cache_subtable<TtfUtil::CmapSubtable4NextCodepoint, TtfUtil::CmapSubtable4Lookup>(m_blocks, bmp_cmap, 0xFFFF))
 108             return;
 109     }
 110 }
 111
 112 CachedCmap::~CachedCmap() throw()
 113 {
 114     if (!m_blocks) return;
 115     unsigned int numBlocks = (m_isBmpOnly)? 0x100 : 0x1100;
 116     for (unsigned int i = 0; i < numBlocks; i++)
 117         free(m_blocks[i]);
 118     free(m_blocks);
 119 }
 120
 121 uint16 CachedCmap::operator [] (const uint32 usv) const throw()
 122 {
 123     if ((m_isBmpOnly && usv > 0xFFFF) || (usv > 0x10FFFF))
 124         return 0;
 125     const uint32 block = 0xFFFF & (usv >> 8);
 126     if (m_blocks[block])
 127         return m_blocks[block][usv & 0xFF];
 128     return 0;
 129 };
 130
 131 CachedCmap::operator bool() const throw()
 132 {
 133     return m_blocks != 0;
 134 }
 135
 136
 137 DirectCmap::DirectCmap(const Face & face)
 138 : _cmap(face, Tag::cmap),
 139   _smp(smp_subtable(_cmap)),
 140   _bmp(bmp_subtable(_cmap))
 141 {
 142 }
 143
 144 uint16 DirectCmap::operator [] (const uint32 usv) const throw()
 145 {
 146     return usv > 0xFFFF
 147             ? (_smp ? TtfUtil::CmapSubtable12Lookup(_smp, usv, 0) : 0)
 148             : TtfUtil::CmapSubtable4Lookup(_bmp, usv, 0);
 149 }
 150
 151 DirectCmap::operator bool () const throw()
 152 {
 153     return _cmap && _bmp;
 154 }
 155