/modules/freetype2/src/type1/t1afm.c
C | 397 lines | 258 code | 85 blank | 54 comment | 52 complexity | 7b54f6e4bead7ded59951433c4709536 MD5 | raw file
1/***************************************************************************/ 2/* */ 3/* t1afm.c */ 4/* */ 5/* AFM support for Type 1 fonts (body). */ 6/* */ 7/* Copyright 1996-2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, */ 8/* 2010 by */ 9/* David Turner, Robert Wilhelm, and Werner Lemberg. */ 10/* */ 11/* This file is part of the FreeType project, and may only be used, */ 12/* modified, and distributed under the terms of the FreeType project */ 13/* license, LICENSE.TXT. By continuing to use, modify, or distribute */ 14/* this file you indicate that you have read the license and */ 15/* understand and accept it fully. */ 16/* */ 17/***************************************************************************/ 18 19 20#include <ft2build.h> 21#include "t1afm.h" 22#include "t1errors.h" 23#include FT_INTERNAL_STREAM_H 24#include FT_INTERNAL_POSTSCRIPT_AUX_H 25 26 27 /*************************************************************************/ 28 /* */ 29 /* The macro FT_COMPONENT is used in trace mode. It is an implicit */ 30 /* parameter of the FT_TRACE() and FT_ERROR() macros, used to print/log */ 31 /* messages during execution. */ 32 /* */ 33#undef FT_COMPONENT 34#define FT_COMPONENT trace_t1afm 35 36 37 FT_LOCAL_DEF( void ) 38 T1_Done_Metrics( FT_Memory memory, 39 AFM_FontInfo fi ) 40 { 41 FT_FREE( fi->KernPairs ); 42 fi->NumKernPair = 0; 43 44 FT_FREE( fi->TrackKerns ); 45 fi->NumTrackKern = 0; 46 47 FT_FREE( fi ); 48 } 49 50 51 /* read a glyph name and return the equivalent glyph index */ 52 static FT_Int 53 t1_get_index( const char* name, 54 FT_Offset len, 55 void* user_data ) 56 { 57 T1_Font type1 = (T1_Font)user_data; 58 FT_Int n; 59 60 61 /* PS string/name length must be < 16-bit */ 62 if ( len > 0xFFFFU ) 63 return 0; 64 65 for ( n = 0; n < type1->num_glyphs; n++ ) 66 { 67 char* gname = (char*)type1->glyph_names[n]; 68 69 70 if ( gname && gname[0] == name[0] && 71 ft_strlen( gname ) == len && 72 ft_strncmp( gname, name, len ) == 0 ) 73 return n; 74 } 75 76 return 0; 77 } 78 79 80#undef KERN_INDEX 81#define KERN_INDEX( g1, g2 ) ( ( (FT_ULong)(g1) << 16 ) | (g2) ) 82 83 84 /* compare two kerning pairs */ 85 FT_CALLBACK_DEF( int ) 86 compare_kern_pairs( const void* a, 87 const void* b ) 88 { 89 AFM_KernPair pair1 = (AFM_KernPair)a; 90 AFM_KernPair pair2 = (AFM_KernPair)b; 91 92 FT_ULong index1 = KERN_INDEX( pair1->index1, pair1->index2 ); 93 FT_ULong index2 = KERN_INDEX( pair2->index1, pair2->index2 ); 94 95 96 if ( index1 > index2 ) 97 return 1; 98 else if ( index1 < index2 ) 99 return -1; 100 else 101 return 0; 102 } 103 104 105 /* parse a PFM file -- for now, only read the kerning pairs */ 106 static FT_Error 107 T1_Read_PFM( FT_Face t1_face, 108 FT_Stream stream, 109 AFM_FontInfo fi ) 110 { 111 FT_Error error = T1_Err_Ok; 112 FT_Memory memory = stream->memory; 113 FT_Byte* start; 114 FT_Byte* limit; 115 FT_Byte* p; 116 AFM_KernPair kp; 117 FT_Int width_table_length; 118 FT_CharMap oldcharmap; 119 FT_CharMap charmap; 120 FT_Int n; 121 122 123 start = (FT_Byte*)stream->cursor; 124 limit = (FT_Byte*)stream->limit; 125 p = start; 126 127 /* Figure out how long the width table is. */ 128 /* This info is a little-endian short at offset 99. */ 129 p = start + 99; 130 if ( p + 2 > limit ) 131 { 132 error = T1_Err_Unknown_File_Format; 133 goto Exit; 134 } 135 width_table_length = FT_PEEK_USHORT_LE( p ); 136 137 p += 18 + width_table_length; 138 if ( p + 0x12 > limit || FT_PEEK_USHORT_LE( p ) < 0x12 ) 139 /* extension table is probably optional */ 140 goto Exit; 141 142 /* Kerning offset is 14 bytes from start of extensions table. */ 143 p += 14; 144 p = start + FT_PEEK_ULONG_LE( p ); 145 146 if ( p == start ) 147 /* zero offset means no table */ 148 goto Exit; 149 150 if ( p + 2 > limit ) 151 { 152 error = T1_Err_Unknown_File_Format; 153 goto Exit; 154 } 155 156 fi->NumKernPair = FT_PEEK_USHORT_LE( p ); 157 p += 2; 158 if ( p + 4 * fi->NumKernPair > limit ) 159 { 160 error = T1_Err_Unknown_File_Format; 161 goto Exit; 162 } 163 164 /* Actually, kerning pairs are simply optional! */ 165 if ( fi->NumKernPair == 0 ) 166 goto Exit; 167 168 /* allocate the pairs */ 169 if ( FT_QNEW_ARRAY( fi->KernPairs, fi->NumKernPair ) ) 170 goto Exit; 171 172 /* now, read each kern pair */ 173 kp = fi->KernPairs; 174 limit = p + 4 * fi->NumKernPair; 175 176 /* PFM kerning data are stored by encoding rather than glyph index, */ 177 /* so find the PostScript charmap of this font and install it */ 178 /* temporarily. If we find no PostScript charmap, then just use */ 179 /* the default and hope it is the right one. */ 180 oldcharmap = t1_face->charmap; 181 charmap = NULL; 182 183 for ( n = 0; n < t1_face->num_charmaps; n++ ) 184 { 185 charmap = t1_face->charmaps[n]; 186 /* check against PostScript pseudo platform */ 187 if ( charmap->platform_id == 7 ) 188 { 189 error = FT_Set_Charmap( t1_face, charmap ); 190 if ( error ) 191 goto Exit; 192 break; 193 } 194 } 195 196 /* Kerning info is stored as: */ 197 /* */ 198 /* encoding of first glyph (1 byte) */ 199 /* encoding of second glyph (1 byte) */ 200 /* offset (little-endian short) */ 201 for ( ; p < limit ; p += 4 ) 202 { 203 kp->index1 = FT_Get_Char_Index( t1_face, p[0] ); 204 kp->index2 = FT_Get_Char_Index( t1_face, p[1] ); 205 206 kp->x = (FT_Int)FT_PEEK_SHORT_LE(p + 2); 207 kp->y = 0; 208 209 kp++; 210 } 211 212 if ( oldcharmap != NULL ) 213 error = FT_Set_Charmap( t1_face, oldcharmap ); 214 if ( error ) 215 goto Exit; 216 217 /* now, sort the kern pairs according to their glyph indices */ 218 ft_qsort( fi->KernPairs, fi->NumKernPair, sizeof ( AFM_KernPairRec ), 219 compare_kern_pairs ); 220 221 Exit: 222 if ( error ) 223 { 224 FT_FREE( fi->KernPairs ); 225 fi->NumKernPair = 0; 226 } 227 228 return error; 229 } 230 231 232 /* parse a metrics file -- either AFM or PFM depending on what */ 233 /* it turns out to be */ 234 FT_LOCAL_DEF( FT_Error ) 235 T1_Read_Metrics( FT_Face t1_face, 236 FT_Stream stream ) 237 { 238 PSAux_Service psaux; 239 FT_Memory memory = stream->memory; 240 AFM_ParserRec parser; 241 AFM_FontInfo fi = NULL; 242 FT_Error error = T1_Err_Unknown_File_Format; 243 T1_Font t1_font = &( (T1_Face)t1_face )->type1; 244 245 246 if ( FT_NEW( fi ) || 247 FT_FRAME_ENTER( stream->size ) ) 248 goto Exit; 249 250 fi->FontBBox = t1_font->font_bbox; 251 fi->Ascender = t1_font->font_bbox.yMax; 252 fi->Descender = t1_font->font_bbox.yMin; 253 254 psaux = (PSAux_Service)( (T1_Face)t1_face )->psaux; 255 if ( psaux && psaux->afm_parser_funcs ) 256 { 257 error = psaux->afm_parser_funcs->init( &parser, 258 stream->memory, 259 stream->cursor, 260 stream->limit ); 261 262 if ( !error ) 263 { 264 parser.FontInfo = fi; 265 parser.get_index = t1_get_index; 266 parser.user_data = t1_font; 267 268 error = psaux->afm_parser_funcs->parse( &parser ); 269 psaux->afm_parser_funcs->done( &parser ); 270 } 271 } 272 273 if ( error == T1_Err_Unknown_File_Format ) 274 { 275 FT_Byte* start = stream->cursor; 276 277 278 /* MS Windows allows versions up to 0x3FF without complaining */ 279 if ( stream->size > 6 && 280 start[1] < 4 && 281 FT_PEEK_ULONG_LE( start + 2 ) == stream->size ) 282 error = T1_Read_PFM( t1_face, stream, fi ); 283 } 284 285 if ( !error ) 286 { 287 t1_font->font_bbox = fi->FontBBox; 288 289 t1_face->bbox.xMin = fi->FontBBox.xMin >> 16; 290 t1_face->bbox.yMin = fi->FontBBox.yMin >> 16; 291 /* no `U' suffix here to 0xFFFF! */ 292 t1_face->bbox.xMax = ( fi->FontBBox.xMax + 0xFFFF ) >> 16; 293 t1_face->bbox.yMax = ( fi->FontBBox.yMax + 0xFFFF ) >> 16; 294 295 /* no `U' suffix here to 0x8000! */ 296 t1_face->ascender = (FT_Short)( ( fi->Ascender + 0x8000 ) >> 16 ); 297 t1_face->descender = (FT_Short)( ( fi->Descender + 0x8000 ) >> 16 ); 298 299 if ( fi->NumKernPair ) 300 { 301 t1_face->face_flags |= FT_FACE_FLAG_KERNING; 302 ( (T1_Face)t1_face )->afm_data = fi; 303 fi = NULL; 304 } 305 } 306 307 FT_FRAME_EXIT(); 308 309 Exit: 310 if ( fi != NULL ) 311 T1_Done_Metrics( memory, fi ); 312 313 return error; 314 } 315 316 317 /* find the kerning for a given glyph pair */ 318 FT_LOCAL_DEF( void ) 319 T1_Get_Kerning( AFM_FontInfo fi, 320 FT_UInt glyph1, 321 FT_UInt glyph2, 322 FT_Vector* kerning ) 323 { 324 AFM_KernPair min, mid, max; 325 FT_ULong idx = KERN_INDEX( glyph1, glyph2 ); 326 327 328 /* simple binary search */ 329 min = fi->KernPairs; 330 max = min + fi->NumKernPair - 1; 331 332 while ( min <= max ) 333 { 334 FT_ULong midi; 335 336 337 mid = min + ( max - min ) / 2; 338 midi = KERN_INDEX( mid->index1, mid->index2 ); 339 340 if ( midi == idx ) 341 { 342 kerning->x = mid->x; 343 kerning->y = mid->y; 344 345 return; 346 } 347 348 if ( midi < idx ) 349 min = mid + 1; 350 else 351 max = mid - 1; 352 } 353 354 kerning->x = 0; 355 kerning->y = 0; 356 } 357 358 359 FT_LOCAL_DEF( FT_Error ) 360 T1_Get_Track_Kerning( FT_Face face, 361 FT_Fixed ptsize, 362 FT_Int degree, 363 FT_Fixed* kerning ) 364 { 365 AFM_FontInfo fi = (AFM_FontInfo)( (T1_Face)face )->afm_data; 366 FT_Int i; 367 368 369 if ( !fi ) 370 return T1_Err_Invalid_Argument; 371 372 for ( i = 0; i < fi->NumTrackKern; i++ ) 373 { 374 AFM_TrackKern tk = fi->TrackKerns + i; 375 376 377 if ( tk->degree != degree ) 378 continue; 379 380 if ( ptsize < tk->min_ptsize ) 381 *kerning = tk->min_kern; 382 else if ( ptsize > tk->max_ptsize ) 383 *kerning = tk->max_kern; 384 else 385 { 386 *kerning = FT_MulDiv( ptsize - tk->min_ptsize, 387 tk->max_kern - tk->min_kern, 388 tk->max_ptsize - tk->min_ptsize ) + 389 tk->min_kern; 390 } 391 } 392 393 return T1_Err_Ok; 394 } 395 396 397/* END */