| 1 | /***************************************************************************/ |
| 2 | /* */ |
| 3 | /* ttdriver.c */ |
| 4 | /* */ |
| 5 | /* TrueType font driver implementation (body). */ |
| 6 | /* */ |
| 7 | /* Copyright 1996-2000 by */ |
| 8 | /* David Turner, Robert Wilhelm, and Werner Lemberg. */ |
| 9 | /* */ |
| 10 | /* This file is part of the FreeType project, and may only be used, */ |
| 11 | /* modified, and distributed under the terms of the FreeType project */ |
| 12 | /* license, LICENSE.TXT. By continuing to use, modify, or distribute */ |
| 13 | /* this file you indicate that you have read the license and */ |
| 14 | /* understand and accept it fully. */ |
| 15 | /* */ |
| 16 | /***************************************************************************/ |
| 17 | |
| 18 | |
| 19 | #include <freetype/internal/ftdebug.h> |
| 20 | #include <freetype/internal/ftstream.h> |
| 21 | #include <freetype/internal/sfnt.h> |
| 22 | #include <freetype/ttnameid.h> |
| 23 | |
| 24 | |
| 25 | #ifdef FT_FLAT_COMPILE |
| 26 | |
| 27 | #include "ttdriver.h" |
| 28 | #include "ttgload.h" |
| 29 | |
| 30 | #else |
| 31 | |
| 32 | #include <truetype/ttdriver.h> |
| 33 | #include <truetype/ttgload.h> |
| 34 | |
| 35 | #endif |
| 36 | |
| 37 | |
| 38 | /*************************************************************************/ |
| 39 | /* */ |
| 40 | /* The macro FT_COMPONENT is used in trace mode. It is an implicit */ |
| 41 | /* parameter of the FT_TRACE() and FT_ERROR() macros, used to print/log */ |
| 42 | /* messages during execution. */ |
| 43 | /* */ |
| 44 | #undef FT_COMPONENT |
| 45 | #define FT_COMPONENT trace_ttdriver |
| 46 | |
| 47 | |
| 48 | /*************************************************************************/ |
| 49 | /*************************************************************************/ |
| 50 | /*************************************************************************/ |
| 51 | /**** ****/ |
| 52 | /**** ****/ |
| 53 | /**** F A C E S ****/ |
| 54 | /**** ****/ |
| 55 | /**** ****/ |
| 56 | /*************************************************************************/ |
| 57 | /*************************************************************************/ |
| 58 | /*************************************************************************/ |
| 59 | |
| 60 | |
| 61 | #undef PAIR_TAG |
| 62 | #define PAIR_TAG( left, right ) ( ( (FT_ULong)left << 16 ) | \ |
| 63 | (FT_ULong)right ) |
| 64 | |
| 65 | |
| 66 | /*************************************************************************/ |
| 67 | /* */ |
| 68 | /* <Function> */ |
| 69 | /* Get_Kerning */ |
| 70 | /* */ |
| 71 | /* <Description> */ |
| 72 | /* A driver method used to return the kerning vector between two */ |
| 73 | /* glyphs of the same face. */ |
| 74 | /* */ |
| 75 | /* <Input> */ |
| 76 | /* face :: A handle to the source face object. */ |
| 77 | /* */ |
| 78 | /* left_glyph :: The index of the left glyph in the kern pair. */ |
| 79 | /* */ |
| 80 | /* right_glyph :: The index of the right glyph in the kern pair. */ |
| 81 | /* */ |
| 82 | /* <Output> */ |
| 83 | /* kerning :: The kerning vector. This is in font units for */ |
| 84 | /* scalable formats, and in pixels for fixed-sizes */ |
| 85 | /* formats. */ |
| 86 | /* */ |
| 87 | /* <Return> */ |
| 88 | /* FreeType error code. 0 means success. */ |
| 89 | /* */ |
| 90 | /* <Note> */ |
| 91 | /* Only horizontal layouts (left-to-right & right-to-left) are */ |
| 92 | /* supported by this function. Other layouts, or more sophisticated */ |
| 93 | /* kernings, are out of scope of this method (the basic driver */ |
| 94 | /* interface is meant to be simple). */ |
| 95 | /* */ |
| 96 | /* They can be implemented by format-specific interfaces. */ |
| 97 | /* */ |
| 98 | static |
| 99 | FT_Error Get_Kerning( TT_Face face, |
| 100 | FT_UInt left_glyph, |
| 101 | FT_UInt right_glyph, |
| 102 | FT_Vector* kerning ) |
| 103 | { |
| 104 | TT_Kern_0_Pair* pair; |
| 105 | |
| 106 | |
| 107 | if ( !face ) |
| 108 | return TT_Err_Invalid_Face_Handle; |
| 109 | |
| 110 | kerning->x = 0; |
| 111 | kerning->y = 0; |
| 112 | |
| 113 | if ( face->kern_pairs ) |
| 114 | { |
| 115 | /* there are some kerning pairs in this font file! */ |
| 116 | FT_ULong search_tag = PAIR_TAG( left_glyph, right_glyph ); |
| 117 | FT_Long left, right; |
| 118 | |
| 119 | |
| 120 | left = 0; |
| 121 | right = face->num_kern_pairs - 1; |
| 122 | |
| 123 | while ( left <= right ) |
| 124 | { |
| 125 | FT_Int middle = left + ( ( right - left ) >> 1 ); |
| 126 | FT_ULong cur_pair; |
| 127 | |
| 128 | |
| 129 | pair = face->kern_pairs + middle; |
| 130 | cur_pair = PAIR_TAG( pair->left, pair->right ); |
| 131 | |
| 132 | if ( cur_pair == search_tag ) |
| 133 | goto Found; |
| 134 | |
| 135 | if ( cur_pair < search_tag ) |
| 136 | left = middle + 1; |
| 137 | else |
| 138 | right = middle - 1; |
| 139 | } |
| 140 | } |
| 141 | |
| 142 | Exit: |
| 143 | return TT_Err_Ok; |
| 144 | |
| 145 | Found: |
| 146 | kerning->x = pair->value; |
| 147 | goto Exit; |
| 148 | } |
| 149 | |
| 150 | |
| 151 | #undef PAIR_TAG |
| 152 | |
| 153 | |
| 154 | /*************************************************************************/ |
| 155 | /*************************************************************************/ |
| 156 | /*************************************************************************/ |
| 157 | /**** ****/ |
| 158 | /**** ****/ |
| 159 | /**** S I Z E S ****/ |
| 160 | /**** ****/ |
| 161 | /**** ****/ |
| 162 | /*************************************************************************/ |
| 163 | /*************************************************************************/ |
| 164 | /*************************************************************************/ |
| 165 | |
| 166 | |
| 167 | /*************************************************************************/ |
| 168 | /* */ |
| 169 | /* <Function> */ |
| 170 | /* Set_Char_Sizes */ |
| 171 | /* */ |
| 172 | /* <Description> */ |
| 173 | /* A driver method used to reset a size's character sizes (horizontal */ |
| 174 | /* and vertical) expressed in fractional points. */ |
| 175 | /* */ |
| 176 | /* <Input> */ |
| 177 | /* char_width :: The character width expressed in 26.6 */ |
| 178 | /* fractional points. */ |
| 179 | /* */ |
| 180 | /* char_height :: The character height expressed in 26.6 */ |
| 181 | /* fractional points. */ |
| 182 | /* */ |
| 183 | /* horz_resolution :: The horizontal resolution of the output device. */ |
| 184 | /* */ |
| 185 | /* vert_resolution :: The vertical resolution of the output device. */ |
| 186 | /* */ |
| 187 | /* <InOut> */ |
| 188 | /* size :: A handle to the target size object. */ |
| 189 | /* */ |
| 190 | /* <Return> */ |
| 191 | /* FreeType error code. 0 means success. */ |
| 192 | /* */ |
| 193 | static |
| 194 | FT_Error Set_Char_Sizes( TT_Size size, |
| 195 | FT_F26Dot6 char_width, |
| 196 | FT_F26Dot6 char_height, |
| 197 | FT_UInt horz_resolution, |
| 198 | FT_UInt vert_resolution ) |
| 199 | { |
| 200 | FT_Size_Metrics* metrics = &size->root.metrics; |
| 201 | TT_Face face = (TT_Face)size->root.face; |
| 202 | FT_Long dim_x, dim_y; |
| 203 | |
| 204 | |
| 205 | /* This bit flag, when set, indicates that the pixel size must be */ |
| 206 | /* truncated to an integer. Nearly all TrueType fonts have this */ |
| 207 | /* bit set, as hinting won't work really well otherwise. */ |
| 208 | /* */ |
| 209 | /* However, for those rare fonts who do not set it, we override */ |
| 210 | /* the default computations performed by the base layer. I */ |
| 211 | /* really don't know whether this is useful, but hey, that's the */ |
| 212 | /* spec :-) */ |
| 213 | /* */ |
| 214 | if ( ( face->header.Flags & 8 ) == 0 ) |
| 215 | { |
| 216 | /* Compute pixel sizes in 26.6 units */ |
| 217 | dim_x = ( char_width * horz_resolution ) / 72; |
| 218 | dim_y = ( char_height * vert_resolution ) / 72; |
| 219 | |
| 220 | metrics->x_scale = FT_DivFix( dim_x, face->root.units_per_EM ); |
| 221 | metrics->y_scale = FT_DivFix( dim_y, face->root.units_per_EM ); |
| 222 | |
| 223 | metrics->x_ppem = (FT_UShort)( dim_x >> 6 ); |
| 224 | metrics->y_ppem = (FT_UShort)( dim_y >> 6 ); |
| 225 | } |
| 226 | |
| 227 | size->ttmetrics.valid = FALSE; |
| 228 | |
| 229 | return TT_Reset_Size( size ); |
| 230 | } |
| 231 | |
| 232 | |
| 233 | /*************************************************************************/ |
| 234 | /* */ |
| 235 | /* <Function> */ |
| 236 | /* Set_Pixel_Sizes */ |
| 237 | /* */ |
| 238 | /* <Description> */ |
| 239 | /* A driver method used to reset a size's character sizes (horizontal */ |
| 240 | /* and vertical) expressed in integer pixels. */ |
| 241 | /* */ |
| 242 | /* <Input> */ |
| 243 | /* pixel_width :: The character width expressed in integer pixels. */ |
| 244 | /* */ |
| 245 | /* pixel_height :: The character height expressed in integer pixels. */ |
| 246 | /* */ |
| 247 | /* <InOut> */ |
| 248 | /* size :: A handle to the target size object. */ |
| 249 | /* */ |
| 250 | /* <Return> */ |
| 251 | /* FreeType error code. 0 means success. */ |
| 252 | /* */ |
| 253 | static |
| 254 | FT_Error Set_Pixel_Sizes( TT_Size size, |
| 255 | FT_UInt pixel_width, |
| 256 | FT_UInt pixel_height ) |
| 257 | { |
| 258 | FT_UNUSED( pixel_width ); |
| 259 | FT_UNUSED( pixel_height ); |
| 260 | |
| 261 | /* many things have been pre-computed by the base layer */ |
| 262 | |
| 263 | size->ttmetrics.valid = FALSE; |
| 264 | |
| 265 | return TT_Reset_Size( size ); |
| 266 | } |
| 267 | |
| 268 | |
| 269 | /*************************************************************************/ |
| 270 | /* */ |
| 271 | /* <Function> */ |
| 272 | /* Load_Glyph */ |
| 273 | /* */ |
| 274 | /* <Description> */ |
| 275 | /* A driver method used to load a glyph within a given glyph slot. */ |
| 276 | /* */ |
| 277 | /* <Input> */ |
| 278 | /* slot :: A handle to the target slot object where the glyph */ |
| 279 | /* will be loaded. */ |
| 280 | /* */ |
| 281 | /* size :: A handle to the source face size at which the glyph */ |
| 282 | /* must be scaled, loaded, etc. */ |
| 283 | /* */ |
| 284 | /* glyph_index :: The index of the glyph in the font file. */ |
| 285 | /* */ |
| 286 | /* load_flags :: A flag indicating what to load for this glyph. The */ |
| 287 | /* FTLOAD_??? constants can be used to control the */ |
| 288 | /* glyph loading process (e.g., whether the outline */ |
| 289 | /* should be scaled, whether to load bitmaps or not, */ |
| 290 | /* whether to hint the outline, etc). */ |
| 291 | /* */ |
| 292 | /* <Return> */ |
| 293 | /* FreeType error code. 0 means success. */ |
| 294 | /* */ |
| 295 | static |
| 296 | FT_Error Load_Glyph( TT_GlyphSlot slot, |
| 297 | TT_Size size, |
| 298 | FT_UShort glyph_index, |
| 299 | FT_UInt load_flags ) |
| 300 | { |
| 301 | FT_Error error; |
| 302 | |
| 303 | |
| 304 | if ( !slot ) |
| 305 | return TT_Err_Invalid_Glyph_Handle; |
| 306 | |
| 307 | /* check whether we want a scaled outline or bitmap */ |
| 308 | if ( !size ) |
| 309 | load_flags |= FT_LOAD_NO_SCALE | FT_LOAD_NO_HINTING; |
| 310 | |
| 311 | if ( load_flags & FT_LOAD_NO_SCALE ) |
| 312 | size = NULL; |
| 313 | |
| 314 | /* reset the size object if necessary */ |
| 315 | if ( size ) |
| 316 | { |
| 317 | /* these two object must have the same parent */ |
| 318 | if ( size->root.face != slot->face ) |
| 319 | return TT_Err_Invalid_Face_Handle; |
| 320 | |
| 321 | if ( !size->ttmetrics.valid ) |
| 322 | { |
| 323 | if ( FT_SET_ERROR( TT_Reset_Size( size ) ) ) |
| 324 | return error; |
| 325 | } |
| 326 | } |
| 327 | |
| 328 | /* now load the glyph outline if necessary */ |
| 329 | error = TT_Load_Glyph( size, slot, glyph_index, load_flags ); |
| 330 | |
| 331 | /* force drop-out mode to 2 - irrelevant now */ |
| 332 | /* slot->outline.dropout_mode = 2; */ |
| 333 | |
| 334 | return error; |
| 335 | } |
| 336 | |
| 337 | |
| 338 | /*************************************************************************/ |
| 339 | /*************************************************************************/ |
| 340 | /*************************************************************************/ |
| 341 | /**** ****/ |
| 342 | /**** ****/ |
| 343 | /**** C H A R A C T E R M A P P I N G S ****/ |
| 344 | /**** ****/ |
| 345 | /**** ****/ |
| 346 | /*************************************************************************/ |
| 347 | /*************************************************************************/ |
| 348 | /*************************************************************************/ |
| 349 | |
| 350 | /*************************************************************************/ |
| 351 | /* */ |
| 352 | /* <Function> */ |
| 353 | /* Get_Char_Index */ |
| 354 | /* */ |
| 355 | /* <Description> */ |
| 356 | /* Uses a charmap to return a given character code's glyph index. */ |
| 357 | /* */ |
| 358 | /* <Input> */ |
| 359 | /* charmap :: A handle to the source charmap object. */ |
| 360 | /* charcode :: The character code. */ |
| 361 | /* */ |
| 362 | /* <Return> */ |
| 363 | /* Glyph index. 0 means `undefined character code'. */ |
| 364 | /* */ |
| 365 | static |
| 366 | FT_UInt Get_Char_Index( TT_CharMap charmap, |
| 367 | FT_Long charcode ) |
| 368 | { |
| 369 | FT_Error error; |
| 370 | TT_Face face; |
| 371 | TT_CMapTable* cmap; |
| 372 | |
| 373 | |
| 374 | cmap = &charmap->cmap; |
| 375 | face = (TT_Face)charmap->root.face; |
| 376 | |
| 377 | /* Load table if needed */ |
| 378 | if ( !cmap->loaded ) |
| 379 | { |
| 380 | SFNT_Interface* sfnt = (SFNT_Interface*)face->sfnt; |
| 381 | |
| 382 | |
| 383 | error = sfnt->load_charmap( face, cmap, face->root.stream ); |
| 384 | if ( error ) |
| 385 | return 0; |
| 386 | |
| 387 | cmap->loaded = TRUE; |
| 388 | } |
| 389 | |
| 390 | if ( cmap->get_index ) |
| 391 | return cmap->get_index( cmap, charcode ); |
| 392 | else |
| 393 | return 0; |
| 394 | } |
| 395 | |
| 396 | |
| 397 | /*************************************************************************/ |
| 398 | /*************************************************************************/ |
| 399 | /*************************************************************************/ |
| 400 | /**** ****/ |
| 401 | /**** ****/ |
| 402 | /**** D R I V E R I N T E R F A C E ****/ |
| 403 | /**** ****/ |
| 404 | /**** ****/ |
| 405 | /*************************************************************************/ |
| 406 | /*************************************************************************/ |
| 407 | /*************************************************************************/ |
| 408 | |
| 409 | |
| 410 | static |
| 411 | FT_Module_Interface tt_get_interface( TT_Driver driver, |
| 412 | const char* interface ) |
| 413 | { |
| 414 | FT_Module sfntd = FT_Get_Module( driver->root.root.library, |
| 415 | "sfnt" ); |
| 416 | SFNT_Interface* sfnt; |
| 417 | |
| 418 | |
| 419 | /* only return the default interface from the SFNT module */ |
| 420 | if ( sfntd ) |
| 421 | { |
| 422 | sfnt = (SFNT_Interface*)( sfntd->clazz->module_interface ); |
| 423 | if ( sfnt ) |
| 424 | return sfnt->get_interface( FT_MODULE( driver ), interface ); |
| 425 | } |
| 426 | |
| 427 | return 0; |
| 428 | } |
| 429 | |
| 430 | |
| 431 | /* The FT_DriverInterface structure is defined in ftdriver.h. */ |
| 432 | |
| 433 | const FT_Driver_Class tt_driver_class = |
| 434 | { |
| 435 | { |
| 436 | ft_module_font_driver | |
| 437 | ft_module_driver_scalable | |
| 438 | #ifdef TT_CONFIG_OPTION_BYTECODE_INTERPRETER |
| 439 | ft_module_driver_has_hinter, |
| 440 | #else |
| 441 | 0, |
| 442 | #endif |
| 443 | |
| 444 | sizeof ( TT_DriverRec ), |
| 445 | |
| 446 | "truetype", /* driver name */ |
| 447 | 0x10000L, /* driver version == 1.0 */ |
| 448 | 0x20000L, /* driver requires FreeType 2.0 or above */ |
| 449 | |
| 450 | (void*)0, /* driver specific interface */ |
| 451 | |
| 452 | (FT_Module_Constructor)TT_Init_Driver, |
| 453 | (FT_Module_Destructor) TT_Done_Driver, |
| 454 | (FT_Module_Requester) tt_get_interface, |
| 455 | }, |
| 456 | |
| 457 | sizeof ( TT_FaceRec ), |
| 458 | sizeof ( TT_SizeRec ), |
| 459 | sizeof ( FT_GlyphSlotRec ), |
| 460 | |
| 461 | |
| 462 | (FTDriver_initFace) TT_Init_Face, |
| 463 | (FTDriver_doneFace) TT_Done_Face, |
| 464 | (FTDriver_initSize) TT_Init_Size, |
| 465 | (FTDriver_doneSize) TT_Done_Size, |
| 466 | (FTDriver_initGlyphSlot)0, |
| 467 | (FTDriver_doneGlyphSlot)0, |
| 468 | |
| 469 | (FTDriver_setCharSizes) Set_Char_Sizes, |
| 470 | (FTDriver_setPixelSizes)Set_Pixel_Sizes, |
| 471 | (FTDriver_loadGlyph) Load_Glyph, |
| 472 | (FTDriver_getCharIndex) Get_Char_Index, |
| 473 | |
| 474 | (FTDriver_getKerning) Get_Kerning, |
| 475 | (FTDriver_attachFile) 0, |
| 476 | (FTDriver_getAdvances) 0 |
| 477 | }; |
| 478 | |
| 479 | |
| 480 | #ifdef FT_CONFIG_OPTION_DYNAMIC_DRIVERS |
| 481 | |
| 482 | |
| 483 | /*************************************************************************/ |
| 484 | /* */ |
| 485 | /* <Function> */ |
| 486 | /* getDriverInterface */ |
| 487 | /* */ |
| 488 | /* <Description> */ |
| 489 | /* This function is used when compiling the TrueType driver as a */ |
| 490 | /* shared library (`.DLL' or `.so'). It will be used by the */ |
| 491 | /* high-level library of FreeType to retrieve the address of the */ |
| 492 | /* driver's generic interface. */ |
| 493 | /* */ |
| 494 | /* It shouldn't be implemented in a static build, as each driver must */ |
| 495 | /* have the same function as an exported entry point. */ |
| 496 | /* */ |
| 497 | /* <Return> */ |
| 498 | /* The address of the TrueType's driver generic interface. The */ |
| 499 | /* format-specific interface can then be retrieved through the method */ |
| 500 | /* interface->get_format_interface. */ |
| 501 | /* */ |
| 502 | EXPORT_FUNC( const FT_Driver_Class* ) getDriverClass( void ) |
| 503 | { |
| 504 | return &tt_driver_class; |
| 505 | } |
| 506 | |
| 507 | |
| 508 | #endif /* CONFIG_OPTION_DYNAMIC_DRIVERS */ |
| 509 | |
| 510 | |
| 511 | /* END */ |