1 /***************************************************************************/ |
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2 /* */ |
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3 /* ftpatent.c */ |
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4 /* */ |
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5 /* FreeType API for checking patented TrueType bytecode instructions */ |
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6 /* (body). */ |
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7 /* */ |
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8 /* Copyright 2007, 2008, 2010 by David Turner. */ |
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9 /* */ |
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10 /* This file is part of the FreeType project, and may only be used, */ |
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11 /* modified, and distributed under the terms of the FreeType project */ |
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12 /* license, LICENSE.TXT. By continuing to use, modify, or distribute */ |
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13 /* this file you indicate that you have read the license and */ |
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14 /* understand and accept it fully. */ |
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15 /* */ |
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16 /***************************************************************************/ |
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17 |
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18 #include <ft2build.h> |
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19 #include FT_FREETYPE_H |
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20 #include FT_TRUETYPE_TAGS_H |
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21 #include FT_INTERNAL_OBJECTS_H |
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22 #include FT_INTERNAL_STREAM_H |
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23 #include FT_SERVICE_SFNT_H |
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24 #include FT_SERVICE_TRUETYPE_GLYF_H |
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25 |
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26 |
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27 static FT_Bool |
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28 _tt_check_patents_in_range( FT_Stream stream, |
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29 FT_ULong size ) |
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30 { |
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31 FT_Bool result = FALSE; |
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32 FT_Error error; |
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33 FT_Bytes p, end; |
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34 |
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35 |
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36 if ( FT_FRAME_ENTER( size ) ) |
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37 return 0; |
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38 |
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39 p = stream->cursor; |
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40 end = p + size; |
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41 |
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42 while ( p < end ) |
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43 { |
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44 switch (p[0]) |
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45 { |
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46 case 0x06: /* SPvTL // */ |
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47 case 0x07: /* SPvTL + */ |
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48 case 0x08: /* SFvTL // */ |
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49 case 0x09: /* SFvTL + */ |
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50 case 0x0A: /* SPvFS */ |
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51 case 0x0B: /* SFvFS */ |
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52 result = TRUE; |
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53 goto Exit; |
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54 |
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55 case 0x40: |
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56 if ( p + 1 >= end ) |
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57 goto Exit; |
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58 |
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59 p += p[1] + 2; |
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60 break; |
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61 |
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62 case 0x41: |
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63 if ( p + 1 >= end ) |
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64 goto Exit; |
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65 |
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66 p += p[1] * 2 + 2; |
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67 break; |
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68 |
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69 case 0x71: /* DELTAP2 */ |
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70 case 0x72: /* DELTAP3 */ |
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71 case 0x73: /* DELTAC0 */ |
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72 case 0x74: /* DELTAC1 */ |
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73 case 0x75: /* DELTAC2 */ |
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74 result = TRUE; |
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75 goto Exit; |
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76 |
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77 case 0xB0: |
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78 case 0xB1: |
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79 case 0xB2: |
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80 case 0xB3: |
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81 case 0xB4: |
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82 case 0xB5: |
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83 case 0xB6: |
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84 case 0xB7: |
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85 p += ( p[0] - 0xB0 ) + 2; |
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86 break; |
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87 |
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88 case 0xB8: |
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89 case 0xB9: |
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90 case 0xBA: |
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91 case 0xBB: |
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92 case 0xBC: |
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93 case 0xBD: |
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94 case 0xBE: |
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95 case 0xBF: |
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96 p += ( p[0] - 0xB8 ) * 2 + 3; |
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97 break; |
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98 |
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99 default: |
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100 p += 1; |
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101 break; |
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102 } |
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103 } |
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104 |
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105 Exit: |
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106 FT_UNUSED( error ); |
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107 FT_FRAME_EXIT(); |
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108 return result; |
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109 } |
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110 |
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111 |
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112 static FT_Bool |
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113 _tt_check_patents_in_table( FT_Face face, |
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114 FT_ULong tag ) |
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115 { |
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116 FT_Stream stream = face->stream; |
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117 FT_Error error = FT_Err_Ok; |
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118 FT_Service_SFNT_Table service; |
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119 FT_Bool result = FALSE; |
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120 |
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121 |
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122 FT_FACE_FIND_SERVICE( face, service, SFNT_TABLE ); |
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123 |
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124 if ( service ) |
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125 { |
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126 FT_UInt i = 0; |
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127 FT_ULong tag_i = 0, offset_i = 0, length_i = 0; |
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128 |
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129 |
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130 for ( i = 0; !error && tag_i != tag ; i++ ) |
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131 error = service->table_info( face, i, |
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132 &tag_i, &offset_i, &length_i ); |
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133 |
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134 if ( error || |
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135 FT_STREAM_SEEK( offset_i ) ) |
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136 goto Exit; |
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137 |
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138 result = _tt_check_patents_in_range( stream, length_i ); |
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139 } |
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140 |
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141 Exit: |
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142 return result; |
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143 } |
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144 |
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145 |
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146 static FT_Bool |
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147 _tt_face_check_patents( FT_Face face ) |
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148 { |
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149 FT_Stream stream = face->stream; |
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150 FT_UInt gindex; |
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151 FT_Error error; |
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152 FT_Bool result; |
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153 |
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154 FT_Service_TTGlyf service; |
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155 |
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156 |
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157 result = _tt_check_patents_in_table( face, TTAG_fpgm ); |
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158 if ( result ) |
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159 goto Exit; |
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160 |
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161 result = _tt_check_patents_in_table( face, TTAG_prep ); |
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162 if ( result ) |
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163 goto Exit; |
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164 |
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165 FT_FACE_FIND_SERVICE( face, service, TT_GLYF ); |
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166 if ( service == NULL ) |
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167 goto Exit; |
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168 |
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169 for ( gindex = 0; gindex < (FT_UInt)face->num_glyphs; gindex++ ) |
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170 { |
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171 FT_ULong offset, num_ins, size; |
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172 FT_Int num_contours; |
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173 |
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174 |
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175 offset = service->get_location( face, gindex, &size ); |
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176 if ( size == 0 ) |
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177 continue; |
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178 |
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179 if ( FT_STREAM_SEEK( offset ) || |
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180 FT_READ_SHORT( num_contours ) ) |
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181 continue; |
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182 |
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183 if ( num_contours >= 0 ) /* simple glyph */ |
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184 { |
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185 if ( FT_STREAM_SKIP( 8 + num_contours * 2 ) ) |
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186 continue; |
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187 } |
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188 else /* compound glyph */ |
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189 { |
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190 FT_Bool has_instr = 0; |
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191 |
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192 |
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193 if ( FT_STREAM_SKIP( 8 ) ) |
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194 continue; |
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195 |
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196 /* now read each component */ |
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197 for (;;) |
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198 { |
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199 FT_UInt flags, toskip; |
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200 |
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201 |
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202 if( FT_READ_USHORT( flags ) ) |
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203 break; |
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204 |
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205 toskip = 2 + 1 + 1; |
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206 |
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207 if ( ( flags & ( 1 << 0 ) ) != 0 ) /* ARGS_ARE_WORDS */ |
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208 toskip += 2; |
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209 |
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210 if ( ( flags & ( 1 << 3 ) ) != 0 ) /* WE_HAVE_A_SCALE */ |
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211 toskip += 2; |
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212 else if ( ( flags & ( 1 << 6 ) ) != 0 ) /* WE_HAVE_X_Y_SCALE */ |
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213 toskip += 4; |
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214 else if ( ( flags & ( 1 << 7 ) ) != 0 ) /* WE_HAVE_A_2x2 */ |
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215 toskip += 8; |
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216 |
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217 if ( ( flags & ( 1 << 8 ) ) != 0 ) /* WE_HAVE_INSTRUCTIONS */ |
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218 has_instr = 1; |
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219 |
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220 if ( FT_STREAM_SKIP( toskip ) ) |
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221 goto NextGlyph; |
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222 |
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223 if ( ( flags & ( 1 << 5 ) ) == 0 ) /* MORE_COMPONENTS */ |
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224 break; |
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225 } |
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226 |
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227 if ( !has_instr ) |
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228 goto NextGlyph; |
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229 } |
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230 |
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231 if ( FT_READ_USHORT( num_ins ) ) |
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232 continue; |
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233 |
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234 result = _tt_check_patents_in_range( stream, num_ins ); |
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235 if ( result ) |
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236 goto Exit; |
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237 |
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238 NextGlyph: |
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239 ; |
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240 } |
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241 |
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242 Exit: |
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243 return result; |
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244 } |
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245 |
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246 |
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247 /* documentation is in freetype.h */ |
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248 |
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249 FT_EXPORT_DEF( FT_Bool ) |
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250 FT_Face_CheckTrueTypePatents( FT_Face face ) |
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251 { |
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252 FT_Bool result = FALSE; |
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253 |
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254 |
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255 if ( face && FT_IS_SFNT( face ) ) |
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256 result = _tt_face_check_patents( face ); |
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257 |
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258 return result; |
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259 } |
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260 |
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261 |
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262 /* documentation is in freetype.h */ |
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263 |
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264 FT_EXPORT_DEF( FT_Bool ) |
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265 FT_Face_SetUnpatentedHinting( FT_Face face, |
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266 FT_Bool value ) |
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267 { |
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268 FT_Bool result = FALSE; |
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269 |
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270 |
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271 #if defined( TT_CONFIG_OPTION_UNPATENTED_HINTING ) && \ |
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272 !defined( TT_CONFIG_OPTION_BYTECODE_INTEPRETER ) |
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273 if ( face && FT_IS_SFNT( face ) ) |
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274 { |
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275 result = !face->internal->ignore_unpatented_hinter; |
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276 face->internal->ignore_unpatented_hinter = !value; |
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277 } |
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278 #else |
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279 FT_UNUSED( face ); |
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280 FT_UNUSED( value ); |
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281 #endif |
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282 |
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283 return result; |
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284 } |
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285 |
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286 /* END */ |
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