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otvmath.c
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00001 /***************************************************************************/ 00002 /* */ 00003 /* otvmath.c */ 00004 /* */ 00005 /* OpenType MATH table validation (body). */ 00006 /* */ 00007 /* Copyright 2007, 2008 by */ 00008 /* David Turner, Robert Wilhelm, and Werner Lemberg. */ 00009 /* */ 00010 /* Written by George Williams. */ 00011 /* */ 00012 /* This file is part of the FreeType project, and may only be used, */ 00013 /* modified, and distributed under the terms of the FreeType project */ 00014 /* license, LICENSE.TXT. By continuing to use, modify, or distribute */ 00015 /* this file you indicate that you have read the license and */ 00016 /* understand and accept it fully. */ 00017 /* */ 00018 /***************************************************************************/ 00019 00020 00021 #include "otvalid.h" 00022 #include "otvcommn.h" 00023 #include "otvgpos.h" 00024 00025 00026 /*************************************************************************/ 00027 /* */ 00028 /* The macro FT_COMPONENT is used in trace mode. It is an implicit */ 00029 /* parameter of the FT_TRACE() and FT_ERROR() macros, used to print/log */ 00030 /* messages during execution. */ 00031 /* */ 00032 #undef FT_COMPONENT 00033 #define FT_COMPONENT trace_otvmath 00034 00035 00036 00037 /*************************************************************************/ 00038 /*************************************************************************/ 00039 /***** *****/ 00040 /***** MATH TYPOGRAPHIC CONSTANTS *****/ 00041 /***** *****/ 00042 /*************************************************************************/ 00043 /*************************************************************************/ 00044 00045 static void 00046 otv_MathConstants_validate( FT_Bytes table, 00047 OTV_Validator valid ) 00048 { 00049 FT_Bytes p = table; 00050 FT_UInt i; 00051 FT_UInt table_size; 00052 00053 OTV_OPTIONAL_TABLE( DeviceTableOffset ); 00054 00055 00056 OTV_NAME_ENTER( "MathConstants" ); 00057 00058 /* 56 constants, 51 have device tables */ 00059 OTV_LIMIT_CHECK( 2 * ( 56 + 51 ) ); 00060 table_size = 2 * ( 56 + 51 ); 00061 00062 p += 4 * 2; /* First 4 constants have no device tables */ 00063 for ( i = 0; i < 51; ++i ) 00064 { 00065 p += 2; /* skip the value */ 00066 OTV_OPTIONAL_OFFSET( DeviceTableOffset ); 00067 OTV_SIZE_CHECK( DeviceTableOffset ); 00068 if ( DeviceTableOffset ) 00069 otv_Device_validate( table + DeviceTableOffset, valid ); 00070 } 00071 00072 OTV_EXIT; 00073 } 00074 00075 00076 /*************************************************************************/ 00077 /*************************************************************************/ 00078 /***** *****/ 00079 /***** MATH ITALICS CORRECTION *****/ 00080 /***** MATH TOP ACCENT ATTACHMENT *****/ 00081 /***** *****/ 00082 /*************************************************************************/ 00083 /*************************************************************************/ 00084 00085 static void 00086 otv_MathItalicsCorrectionInfo_validate( FT_Bytes table, 00087 OTV_Validator valid, 00088 FT_Int isItalic ) 00089 { 00090 FT_Bytes p = table; 00091 FT_UInt i, cnt, table_size ; 00092 00093 OTV_OPTIONAL_TABLE( Coverage ); 00094 OTV_OPTIONAL_TABLE( DeviceTableOffset ); 00095 00096 FT_UNUSED( isItalic ); /* only used if tracing is active */ 00097 00098 00099 OTV_NAME_ENTER( isItalic ? "MathItalicsCorrectionInfo" 00100 : "MathTopAccentAttachment" ); 00101 00102 OTV_LIMIT_CHECK( 4 ); 00103 00104 OTV_OPTIONAL_OFFSET( Coverage ); 00105 cnt = FT_NEXT_USHORT( p ); 00106 00107 OTV_LIMIT_CHECK( 4 * cnt ); 00108 table_size = 4 + 4 * cnt; 00109 00110 OTV_SIZE_CHECK( Coverage ); 00111 otv_Coverage_validate( table + Coverage, valid, cnt ); 00112 00113 for ( i = 0; i < cnt; ++i ) 00114 { 00115 p += 2; /* Skip the value */ 00116 OTV_OPTIONAL_OFFSET( DeviceTableOffset ); 00117 OTV_SIZE_CHECK( DeviceTableOffset ); 00118 if ( DeviceTableOffset ) 00119 otv_Device_validate( table + DeviceTableOffset, valid ); 00120 } 00121 00122 OTV_EXIT; 00123 } 00124 00125 00126 /*************************************************************************/ 00127 /*************************************************************************/ 00128 /***** *****/ 00129 /***** MATH KERNING *****/ 00130 /***** *****/ 00131 /*************************************************************************/ 00132 /*************************************************************************/ 00133 00134 static void 00135 otv_MathKern_validate( FT_Bytes table, 00136 OTV_Validator valid ) 00137 { 00138 FT_Bytes p = table; 00139 FT_UInt i, cnt, table_size; 00140 00141 OTV_OPTIONAL_TABLE( DeviceTableOffset ); 00142 00143 00144 /* OTV_NAME_ENTER( "MathKern" );*/ 00145 00146 OTV_LIMIT_CHECK( 2 ); 00147 00148 cnt = FT_NEXT_USHORT( p ); 00149 00150 OTV_LIMIT_CHECK( 4 * cnt + 2 ); 00151 table_size = 4 + 4 * cnt; 00152 00153 /* Heights */ 00154 for ( i = 0; i < cnt; ++i ) 00155 { 00156 p += 2; /* Skip the value */ 00157 OTV_OPTIONAL_OFFSET( DeviceTableOffset ); 00158 OTV_SIZE_CHECK( DeviceTableOffset ); 00159 if ( DeviceTableOffset ) 00160 otv_Device_validate( table + DeviceTableOffset, valid ); 00161 } 00162 00163 /* One more Kerning value */ 00164 for ( i = 0; i < cnt + 1; ++i ) 00165 { 00166 p += 2; /* Skip the value */ 00167 OTV_OPTIONAL_OFFSET( DeviceTableOffset ); 00168 OTV_SIZE_CHECK( DeviceTableOffset ); 00169 if ( DeviceTableOffset ) 00170 otv_Device_validate( table + DeviceTableOffset, valid ); 00171 } 00172 00173 OTV_EXIT; 00174 } 00175 00176 00177 static void 00178 otv_MathKernInfo_validate( FT_Bytes table, 00179 OTV_Validator valid ) 00180 { 00181 FT_Bytes p = table; 00182 FT_UInt i, j, cnt, table_size; 00183 00184 OTV_OPTIONAL_TABLE( Coverage ); 00185 OTV_OPTIONAL_TABLE( MKRecordOffset ); 00186 00187 00188 OTV_NAME_ENTER( "MathKernInfo" ); 00189 00190 OTV_LIMIT_CHECK( 4 ); 00191 00192 OTV_OPTIONAL_OFFSET( Coverage ); 00193 cnt = FT_NEXT_USHORT( p ); 00194 00195 OTV_LIMIT_CHECK( 8 * cnt ); 00196 table_size = 4 + 8 * cnt; 00197 00198 OTV_SIZE_CHECK( Coverage ); 00199 otv_Coverage_validate( table + Coverage, valid, cnt ); 00200 00201 for ( i = 0; i < cnt; ++i ) 00202 { 00203 for ( j = 0; j < 4; ++j ) 00204 { 00205 OTV_OPTIONAL_OFFSET( MKRecordOffset ); 00206 OTV_SIZE_CHECK( MKRecordOffset ); 00207 if ( MKRecordOffset ) 00208 otv_MathKern_validate( table + MKRecordOffset, valid ); 00209 } 00210 } 00211 00212 OTV_EXIT; 00213 } 00214 00215 00216 /*************************************************************************/ 00217 /*************************************************************************/ 00218 /***** *****/ 00219 /***** MATH GLYPH INFO *****/ 00220 /***** *****/ 00221 /*************************************************************************/ 00222 /*************************************************************************/ 00223 00224 static void 00225 otv_MathGlyphInfo_validate( FT_Bytes table, 00226 OTV_Validator valid ) 00227 { 00228 FT_Bytes p = table; 00229 FT_UInt MathItalicsCorrectionInfo, MathTopAccentAttachment; 00230 FT_UInt ExtendedShapeCoverage, MathKernInfo; 00231 00232 00233 OTV_NAME_ENTER( "MathGlyphInfo" ); 00234 00235 OTV_LIMIT_CHECK( 8 ); 00236 00237 MathItalicsCorrectionInfo = FT_NEXT_USHORT( p ); 00238 MathTopAccentAttachment = FT_NEXT_USHORT( p ); 00239 ExtendedShapeCoverage = FT_NEXT_USHORT( p ); 00240 MathKernInfo = FT_NEXT_USHORT( p ); 00241 00242 if ( MathItalicsCorrectionInfo ) 00243 otv_MathItalicsCorrectionInfo_validate( 00244 table + MathItalicsCorrectionInfo, valid, TRUE ); 00245 00246 /* Italic correction and Top Accent Attachment have the same format */ 00247 if ( MathTopAccentAttachment ) 00248 otv_MathItalicsCorrectionInfo_validate( 00249 table + MathTopAccentAttachment, valid, FALSE ); 00250 00251 if ( ExtendedShapeCoverage ) 00252 { 00253 OTV_NAME_ENTER( "ExtendedShapeCoverage" ); 00254 otv_Coverage_validate( table + ExtendedShapeCoverage, valid, -1 ); 00255 OTV_EXIT; 00256 } 00257 00258 if ( MathKernInfo ) 00259 otv_MathKernInfo_validate( table + MathKernInfo, valid ); 00260 00261 OTV_EXIT; 00262 } 00263 00264 00265 /*************************************************************************/ 00266 /*************************************************************************/ 00267 /***** *****/ 00268 /***** MATH GLYPH CONSTRUCTION *****/ 00269 /***** *****/ 00270 /*************************************************************************/ 00271 /*************************************************************************/ 00272 00273 static void 00274 otv_GlyphAssembly_validate( FT_Bytes table, 00275 OTV_Validator valid ) 00276 { 00277 FT_Bytes p = table; 00278 FT_UInt pcnt, table_size; 00279 FT_UInt i; 00280 00281 OTV_OPTIONAL_TABLE( DeviceTableOffset ); 00282 00283 00284 /* OTV_NAME_ENTER( "GlyphAssembly" ); */ 00285 00286 OTV_LIMIT_CHECK( 6 ); 00287 00288 p += 2; /* Skip the Italics Correction value */ 00289 OTV_OPTIONAL_OFFSET( DeviceTableOffset ); 00290 pcnt = FT_NEXT_USHORT( p ); 00291 00292 OTV_LIMIT_CHECK( 8 * pcnt ); 00293 table_size = 6 + 8 * pcnt; 00294 00295 OTV_SIZE_CHECK( DeviceTableOffset ); 00296 if ( DeviceTableOffset ) 00297 otv_Device_validate( table + DeviceTableOffset, valid ); 00298 00299 for ( i = 0; i < pcnt; ++i ) 00300 { 00301 FT_UInt gid; 00302 00303 00304 gid = FT_NEXT_USHORT( p ); 00305 if ( gid >= valid->glyph_count ) 00306 FT_INVALID_GLYPH_ID; 00307 p += 2*4; /* skip the Start, End, Full, and Flags fields */ 00308 } 00309 00310 /* OTV_EXIT; */ 00311 } 00312 00313 00314 static void 00315 otv_MathGlyphConstruction_validate( FT_Bytes table, 00316 OTV_Validator valid ) 00317 { 00318 FT_Bytes p = table; 00319 FT_UInt vcnt, table_size; 00320 FT_UInt i; 00321 00322 OTV_OPTIONAL_TABLE( GlyphAssembly ); 00323 00324 00325 /* OTV_NAME_ENTER( "MathGlyphConstruction" ); */ 00326 00327 OTV_LIMIT_CHECK( 4 ); 00328 00329 OTV_OPTIONAL_OFFSET( GlyphAssembly ); 00330 vcnt = FT_NEXT_USHORT( p ); 00331 00332 OTV_LIMIT_CHECK( 4 * vcnt ); 00333 table_size = 4 + 4 * vcnt; 00334 00335 for ( i = 0; i < vcnt; ++i ) 00336 { 00337 FT_UInt gid; 00338 00339 00340 gid = FT_NEXT_USHORT( p ); 00341 if ( gid >= valid->glyph_count ) 00342 FT_INVALID_GLYPH_ID; 00343 p += 2; /* skip the size */ 00344 } 00345 00346 OTV_SIZE_CHECK( GlyphAssembly ); 00347 if ( GlyphAssembly ) 00348 otv_GlyphAssembly_validate( table+GlyphAssembly, valid ); 00349 00350 /* OTV_EXIT; */ 00351 } 00352 00353 00354 static void 00355 otv_MathVariants_validate( FT_Bytes table, 00356 OTV_Validator valid ) 00357 { 00358 FT_Bytes p = table; 00359 FT_UInt vcnt, hcnt, i, table_size; 00360 00361 OTV_OPTIONAL_TABLE( VCoverage ); 00362 OTV_OPTIONAL_TABLE( HCoverage ); 00363 OTV_OPTIONAL_TABLE( Offset ); 00364 00365 00366 OTV_NAME_ENTER( "MathVariants" ); 00367 00368 OTV_LIMIT_CHECK( 10 ); 00369 00370 p += 2; /* Skip the MinConnectorOverlap constant */ 00371 OTV_OPTIONAL_OFFSET( VCoverage ); 00372 OTV_OPTIONAL_OFFSET( HCoverage ); 00373 vcnt = FT_NEXT_USHORT( p ); 00374 hcnt = FT_NEXT_USHORT( p ); 00375 00376 OTV_LIMIT_CHECK( 2 * vcnt + 2 * hcnt ); 00377 table_size = 10 + 2 * vcnt + 2 * hcnt; 00378 00379 OTV_SIZE_CHECK( VCoverage ); 00380 if ( VCoverage ) 00381 otv_Coverage_validate( table + VCoverage, valid, vcnt ); 00382 00383 OTV_SIZE_CHECK( HCoverage ); 00384 if ( HCoverage ) 00385 otv_Coverage_validate( table + HCoverage, valid, hcnt ); 00386 00387 for ( i = 0; i < vcnt; ++i ) 00388 { 00389 OTV_OPTIONAL_OFFSET( Offset ); 00390 OTV_SIZE_CHECK( Offset ); 00391 otv_MathGlyphConstruction_validate( table + Offset, valid ); 00392 } 00393 00394 for ( i = 0; i < hcnt; ++i ) 00395 { 00396 OTV_OPTIONAL_OFFSET( Offset ); 00397 OTV_SIZE_CHECK( Offset ); 00398 otv_MathGlyphConstruction_validate( table + Offset, valid ); 00399 } 00400 00401 OTV_EXIT; 00402 } 00403 00404 00405 /*************************************************************************/ 00406 /*************************************************************************/ 00407 /***** *****/ 00408 /***** MATH TABLE *****/ 00409 /***** *****/ 00410 /*************************************************************************/ 00411 /*************************************************************************/ 00412 00413 /* sets valid->glyph_count */ 00414 00415 FT_LOCAL_DEF( void ) 00416 otv_MATH_validate( FT_Bytes table, 00417 FT_UInt glyph_count, 00418 FT_Validator ftvalid ) 00419 { 00420 OTV_ValidatorRec validrec; 00421 OTV_Validator valid = &validrec; 00422 FT_Bytes p = table; 00423 FT_UInt MathConstants, MathGlyphInfo, MathVariants; 00424 00425 00426 valid->root = ftvalid; 00427 00428 FT_TRACE3(( "validating MATH table\n" )); 00429 OTV_INIT; 00430 00431 OTV_LIMIT_CHECK( 10 ); 00432 00433 if ( FT_NEXT_ULONG( p ) != 0x10000UL ) /* Version */ 00434 FT_INVALID_FORMAT; 00435 00436 MathConstants = FT_NEXT_USHORT( p ); 00437 MathGlyphInfo = FT_NEXT_USHORT( p ); 00438 MathVariants = FT_NEXT_USHORT( p ); 00439 00440 valid->glyph_count = glyph_count; 00441 00442 otv_MathConstants_validate( table + MathConstants, 00443 valid ); 00444 otv_MathGlyphInfo_validate( table + MathGlyphInfo, 00445 valid ); 00446 otv_MathVariants_validate ( table + MathVariants, 00447 valid ); 00448 00449 FT_TRACE4(( "\n" )); 00450 } 00451 00452 00453 /* END */
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