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1 /* GRAPHITE2 LICENSING |
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2 |
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3 Copyright 2012, SIL International |
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4 All rights reserved. |
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5 |
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6 This library is free software; you can redistribute it and/or modify |
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7 it under the terms of the GNU Lesser General Public License as published |
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8 by the Free Software Foundation; either version 2.1 of License, or |
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9 (at your option) any later version. |
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10 |
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11 This program is distributed in the hope that it will be useful, |
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12 but WITHOUT ANY WARRANTY; without even the implied warranty of |
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13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
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14 Lesser General Public License for more details. |
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15 |
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16 You should also have received a copy of the GNU Lesser General Public |
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17 License along with this library in the file named "LICENSE". |
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18 If not, write to the Free Software Foundation, 51 Franklin Street, |
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19 Suite 500, Boston, MA 02110-1335, USA or visit their web page on the |
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20 internet at http://www.fsf.org/licenses/lgpl.html. |
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21 |
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22 Alternatively, the contents of this file may be used under the terms of the |
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23 Mozilla Public License (http://mozilla.org/MPL) or the GNU General Public |
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24 License, as published by the Free Software Foundation, either version 2 |
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25 of the License or (at your option) any later version. |
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26 */ |
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27 #include "graphite2/Font.h" |
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28 |
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29 #include "inc/Main.h" |
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30 #include "inc/Face.h" //for the tags |
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31 #include "inc/GlyphCache.h" |
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32 #include "inc/GlyphFace.h" |
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33 #include "inc/Endian.h" |
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34 |
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35 using namespace graphite2; |
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36 |
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37 namespace |
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38 { |
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39 // Iterator over version 1 or 2 glat entries which consist of a series of |
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40 // +-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+ |
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41 // v1 |k|n|v1 |v2 |...|vN | or v2 | k | n |v1 |v2 |...|vN | |
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42 // +-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+ |
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43 // variable length structures. |
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44 |
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45 template<typename W> |
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46 class _glat_iterator : public std::iterator<std::input_iterator_tag, std::pair<sparse::key_type, sparse::mapped_type> > |
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47 { |
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48 unsigned short key() const { return be::peek<W>(_e) + _n; } |
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49 unsigned int run() const { return be::peek<W>(_e+sizeof(W)); } |
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50 void advance_entry() { _n = 0; _e = _v; be::skip<W>(_v,2); } |
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51 public: |
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52 _glat_iterator(const void * glat=0) : _e(reinterpret_cast<const byte *>(glat)), _v(_e+2*sizeof(W)), _n(0) {} |
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53 |
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54 _glat_iterator<W> & operator ++ () { |
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55 ++_n; be::skip<uint16>(_v); |
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56 if (_n == run()) advance_entry(); |
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57 return *this; |
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58 } |
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59 _glat_iterator<W> operator ++ (int) { _glat_iterator<W> tmp(*this); operator++(); return tmp; } |
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60 |
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61 // This is strictly a >= operator. A true == operator could be |
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62 // implemented that test for overlap but it would be more expensive a |
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63 // test. |
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64 bool operator == (const _glat_iterator<W> & rhs) { return _v >= rhs._e; } |
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65 bool operator != (const _glat_iterator<W> & rhs) { return !operator==(rhs); } |
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66 |
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67 value_type operator * () const { |
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68 return value_type(key(), be::peek<uint16>(_v)); |
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69 } |
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70 |
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71 protected: |
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72 const byte * _e, * _v; |
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73 ptrdiff_t _n; |
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74 }; |
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75 |
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76 typedef _glat_iterator<uint8> glat_iterator; |
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77 typedef _glat_iterator<uint16> glat2_iterator; |
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78 } |
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79 |
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80 |
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81 class GlyphCache::Loader |
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82 { |
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83 public: |
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84 Loader(const Face & face, const bool dumb_font); //return result indicates success. Do not use if failed. |
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85 |
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86 operator bool () const throw(); |
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87 unsigned short int units_per_em() const throw(); |
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88 unsigned short int num_glyphs() const throw(); |
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89 unsigned short int num_attrs() const throw(); |
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90 |
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91 const GlyphFace * read_glyph(unsigned short gid, GlyphFace &) const throw(); |
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92 |
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93 CLASS_NEW_DELETE; |
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94 private: |
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95 Face::Table _head, |
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96 _hhea, |
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97 _hmtx, |
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98 _glyf, |
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99 _loca, |
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100 m_pGlat, |
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101 m_pGloc; |
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102 |
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103 bool _long_fmt; |
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104 unsigned short _num_glyphs_graphics, //i.e. boundary box and advance |
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105 _num_glyphs_attributes, |
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106 _num_attrs; // number of glyph attributes per glyph |
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107 }; |
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108 |
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109 |
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110 |
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111 GlyphCache::GlyphCache(const Face & face, const uint32 face_options) |
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112 : _glyph_loader(new Loader(face, bool(face_options & gr_face_dumbRendering))), |
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113 _glyphs(_glyph_loader && *_glyph_loader ? grzeroalloc<const GlyphFace *>(_glyph_loader->num_glyphs()) : 0), |
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114 _num_glyphs(_glyphs ? _glyph_loader->num_glyphs() : 0), |
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115 _num_attrs(_glyphs ? _glyph_loader->num_attrs() : 0), |
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116 _upem(_glyphs ? _glyph_loader->units_per_em() : 0) |
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117 { |
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118 if ((face_options & gr_face_preloadGlyphs) && _glyph_loader && _glyphs) |
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119 { |
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120 GlyphFace * const glyphs = new GlyphFace [_num_glyphs]; |
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121 if (!glyphs) |
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122 return; |
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123 |
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124 // The 0 glyph is definately required. |
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125 _glyphs[0] = _glyph_loader->read_glyph(0, glyphs[0]); |
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126 |
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127 // glyphs[0] has the same address as the glyphs array just allocated, |
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128 // thus assigning the &glyphs[0] to _glyphs[0] means _glyphs[0] points |
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129 // to the entire array. |
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130 const GlyphFace * loaded = _glyphs[0]; |
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131 for (uint16 gid = 1; loaded && gid != _num_glyphs; ++gid) |
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132 _glyphs[gid] = loaded = _glyph_loader->read_glyph(gid, glyphs[gid]); |
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133 |
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134 if (!loaded) |
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135 { |
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136 _glyphs[0] = 0; |
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137 delete [] glyphs; |
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138 } |
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139 delete _glyph_loader; |
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140 _glyph_loader = 0; |
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141 } |
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142 |
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143 if (_glyphs && glyph(0) == 0) |
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144 { |
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145 free(_glyphs); |
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146 _glyphs = 0; |
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147 _num_glyphs = _num_attrs = _upem = 0; |
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148 } |
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149 } |
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150 |
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151 |
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152 GlyphCache::~GlyphCache() |
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153 { |
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154 if (_glyphs) |
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155 { |
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156 if (_glyph_loader) |
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157 { |
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158 const GlyphFace * * g = _glyphs; |
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159 for(unsigned short n = _num_glyphs; n; --n, ++g) |
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160 delete *g; |
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161 } |
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162 else |
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163 delete [] _glyphs[0]; |
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164 free(_glyphs); |
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165 } |
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166 delete _glyph_loader; |
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167 } |
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168 |
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169 const GlyphFace *GlyphCache::glyph(unsigned short glyphid) const //result may be changed by subsequent call with a different glyphid |
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170 { |
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171 const GlyphFace * & p = _glyphs[glyphid]; |
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172 if (p == 0 && _glyph_loader) |
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173 { |
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174 GlyphFace * g = new GlyphFace(); |
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175 if (g) p = _glyph_loader->read_glyph(glyphid, *g); |
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176 if (!p) |
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177 { |
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178 delete g; |
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179 return *_glyphs; |
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180 } |
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181 } |
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182 return p; |
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183 } |
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184 |
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185 |
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186 |
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187 GlyphCache::Loader::Loader(const Face & face, const bool dumb_font) |
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188 : _head(face, Tag::head), |
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189 _hhea(face, Tag::hhea), |
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190 _hmtx(face, Tag::hmtx), |
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191 _glyf(face, Tag::glyf), |
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192 _loca(face, Tag::loca), |
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193 _long_fmt(false), |
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194 _num_glyphs_graphics(0), |
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195 _num_glyphs_attributes(0), |
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196 _num_attrs(0) |
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197 { |
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198 if (!operator bool()) |
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199 return; |
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200 |
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201 const Face::Table maxp = Face::Table(face, Tag::maxp); |
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202 if (!maxp) { _head = Face::Table(); return; } |
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203 |
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204 _num_glyphs_graphics = TtfUtil::GlyphCount(maxp); |
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205 // This will fail if the number of glyphs is wildly out of range. |
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206 if (_glyf && TtfUtil::LocaLookup(_num_glyphs_graphics-1, _loca, _loca.size(), _head) == size_t(-1)) |
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207 { |
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208 _head = Face::Table(); |
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209 return; |
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210 } |
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211 |
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212 if (!dumb_font) |
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213 { |
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214 if ((m_pGlat = Face::Table(face, Tag::Glat)) == NULL |
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215 || (m_pGloc = Face::Table(face, Tag::Gloc)) == NULL |
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216 || m_pGloc.size() < 6) |
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217 { |
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218 _head = Face::Table(); |
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219 return; |
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220 } |
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221 const byte * p = m_pGloc; |
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222 const int version = be::read<uint32>(p); |
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223 const uint16 flags = be::read<uint16>(p); |
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224 _num_attrs = be::read<uint16>(p); |
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225 // We can accurately calculate the number of attributed glyphs by |
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226 // subtracting the length of the attribids array (numAttribs long if present) |
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227 // and dividing by either 2 or 4 depending on shor or lonf format |
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228 _long_fmt = flags & 1; |
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229 _num_glyphs_attributes = (m_pGloc.size() |
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230 - (p - m_pGloc) |
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231 - sizeof(uint16)*(flags & 0x2 ? _num_attrs : 0)) |
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232 / (_long_fmt ? sizeof(uint32) : sizeof(uint16)) - 1; |
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233 |
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234 if (version != 0x00010000 |
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235 || _num_attrs == 0 || _num_attrs > 0x3000 // is this hard limit appropriate? |
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236 || _num_glyphs_graphics > _num_glyphs_attributes) |
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237 { |
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238 _head = Face::Table(); |
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239 return; |
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240 } |
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241 } |
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242 } |
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243 |
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244 inline |
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245 GlyphCache::Loader::operator bool () const throw() |
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246 { |
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247 return _head && _hhea && _hmtx && !(bool(_glyf) != bool(_loca)); |
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248 } |
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249 |
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250 inline |
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251 unsigned short int GlyphCache::Loader::units_per_em() const throw() |
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252 { |
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253 return _head ? TtfUtil::DesignUnits(_head) : 0; |
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254 } |
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255 |
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256 inline |
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257 unsigned short int GlyphCache::Loader::num_glyphs() const throw() |
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258 { |
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259 return max(_num_glyphs_graphics, _num_glyphs_attributes); |
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260 } |
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261 |
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262 inline |
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263 unsigned short int GlyphCache::Loader::num_attrs() const throw() |
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264 { |
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265 return _num_attrs; |
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266 } |
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267 |
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268 const GlyphFace * GlyphCache::Loader::read_glyph(unsigned short glyphid, GlyphFace & glyph) const throw() |
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269 { |
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270 Rect bbox; |
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271 Position advance; |
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272 |
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273 if (glyphid < _num_glyphs_graphics) |
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274 { |
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275 int nLsb; |
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276 unsigned int nAdvWid; |
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277 if (_glyf) |
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278 { |
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279 int xMin, yMin, xMax, yMax; |
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280 size_t locidx = TtfUtil::LocaLookup(glyphid, _loca, _loca.size(), _head); |
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281 void *pGlyph = TtfUtil::GlyfLookup(_glyf, locidx, _glyf.size()); |
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282 |
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283 if (pGlyph && TtfUtil::GlyfBox(pGlyph, xMin, yMin, xMax, yMax)) |
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284 bbox = Rect(Position(static_cast<float>(xMin), static_cast<float>(yMin)), |
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285 Position(static_cast<float>(xMax), static_cast<float>(yMax))); |
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286 } |
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287 if (TtfUtil::HorMetrics(glyphid, _hmtx, _hmtx.size(), _hhea, nLsb, nAdvWid)) |
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288 advance = Position(static_cast<float>(nAdvWid), 0); |
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289 } |
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290 |
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291 if (glyphid < _num_glyphs_attributes) |
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292 { |
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293 const byte * gloc = m_pGloc; |
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294 size_t glocs = 0, gloce = 0; |
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295 |
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296 be::skip<uint32>(gloc); |
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297 be::skip<uint16>(gloc,2); |
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298 if (_long_fmt) |
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299 { |
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300 be::skip<uint32>(gloc, glyphid); |
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301 glocs = be::read<uint32>(gloc); |
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302 gloce = be::peek<uint32>(gloc); |
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303 } |
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304 else |
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305 { |
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306 be::skip<uint16>(gloc, glyphid); |
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307 glocs = be::read<uint16>(gloc); |
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308 gloce = be::peek<uint16>(gloc); |
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309 } |
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310 |
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311 if (glocs >= m_pGlat.size() || gloce > m_pGlat.size()) |
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312 return 0; |
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313 |
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314 const uint32 glat_version = be::peek<uint32>(m_pGlat); |
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315 if (glat_version < 0x00020000) |
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316 { |
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317 if (gloce - glocs < 2*sizeof(byte)+sizeof(uint16) |
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318 || gloce - glocs > _num_attrs*(2*sizeof(byte)+sizeof(uint16))) |
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319 { |
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320 return 0; |
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321 } |
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322 |
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323 new (&glyph) GlyphFace(bbox, advance, glat_iterator(m_pGlat + glocs), glat_iterator(m_pGlat + gloce)); |
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324 } |
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325 else |
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326 { |
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327 if (gloce - glocs < 3*sizeof(uint16) |
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328 || gloce - glocs > _num_attrs*3*sizeof(uint16)) |
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329 { |
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330 return 0; |
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331 } |
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332 |
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333 new (&glyph) GlyphFace(bbox, advance, glat2_iterator(m_pGlat + glocs), glat2_iterator(m_pGlat + gloce)); |
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334 } |
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335 |
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336 if (!glyph.attrs() || glyph.attrs().capacity() > _num_attrs) |
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337 return 0; |
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338 } |
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339 |
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340 return &glyph; |
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341 } |