ttsbit.c revision 77f63d23f7d380b0ff02c18fd6a154ab9063128a
1/***************************************************************************/ 2/* */ 3/* ttsbit.c */ 4/* */ 5/* TrueType and OpenType embedded bitmap support (body). */ 6/* */ 7/* Copyright 1996-2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009 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#include <ft2build.h> 19#include FT_INTERNAL_DEBUG_H 20#include FT_INTERNAL_STREAM_H 21#include FT_TRUETYPE_TAGS_H 22 23 /* 24 * Alas, the memory-optimized sbit loader can't be used when implementing 25 * the `old internals' hack 26 */ 27#ifndef FT_CONFIG_OPTION_OLD_INTERNALS 28 29#include "ttsbit0.c" 30 31#else /* FT_CONFIG_OPTION_OLD_INTERNALS */ 32 33#include <ft2build.h> 34#include FT_INTERNAL_DEBUG_H 35#include FT_INTERNAL_STREAM_H 36#include FT_TRUETYPE_TAGS_H 37#include "ttsbit.h" 38 39#include "sferrors.h" 40 41 42 /*************************************************************************/ 43 /* */ 44 /* The macro FT_COMPONENT is used in trace mode. It is an implicit */ 45 /* parameter of the FT_TRACE() and FT_ERROR() macros, used to print/log */ 46 /* messages during execution. */ 47 /* */ 48#undef FT_COMPONENT 49#define FT_COMPONENT trace_ttsbit 50 51 52 /*************************************************************************/ 53 /* */ 54 /* <Function> */ 55 /* blit_sbit */ 56 /* */ 57 /* <Description> */ 58 /* Blits a bitmap from an input stream into a given target. Supports */ 59 /* x and y offsets as well as byte padded lines. */ 60 /* */ 61 /* <Input> */ 62 /* target :: The target bitmap/pixmap. */ 63 /* */ 64 /* source :: The input packed bitmap data. */ 65 /* */ 66 /* line_bits :: The number of bits per line. */ 67 /* */ 68 /* byte_padded :: A flag which is true if lines are byte-padded. */ 69 /* */ 70 /* x_offset :: The horizontal offset. */ 71 /* */ 72 /* y_offset :: The vertical offset. */ 73 /* */ 74 /* <Note> */ 75 /* IMPORTANT: The x and y offsets are relative to the top corner of */ 76 /* the target bitmap (unlike the normal TrueType */ 77 /* convention). A positive y offset indicates a downwards */ 78 /* direction! */ 79 /* */ 80 static void 81 blit_sbit( FT_Bitmap* target, 82 FT_Byte* source, 83 FT_Int line_bits, 84 FT_Bool byte_padded, 85 FT_Int x_offset, 86 FT_Int y_offset, 87 FT_Int source_height ) 88 { 89 FT_Byte* line_buff; 90 FT_Int line_incr; 91 FT_Int height; 92 93 FT_UShort acc; 94 FT_UInt loaded; 95 96 97 /* first of all, compute starting write position */ 98 line_incr = target->pitch; 99 line_buff = target->buffer; 100 101 if ( line_incr < 0 ) 102 line_buff -= line_incr * ( target->rows - 1 ); 103 104 line_buff += ( x_offset >> 3 ) + y_offset * line_incr; 105 106 /***********************************************************************/ 107 /* */ 108 /* We use the extra-classic `accumulator' trick to extract the bits */ 109 /* from the source byte stream. */ 110 /* */ 111 /* Namely, the variable `acc' is a 16-bit accumulator containing the */ 112 /* last `loaded' bits from the input stream. The bits are shifted to */ 113 /* the upmost position in `acc'. */ 114 /* */ 115 /***********************************************************************/ 116 117 acc = 0; /* clear accumulator */ 118 loaded = 0; /* no bits were loaded */ 119 120 for ( height = source_height; height > 0; height-- ) 121 { 122 FT_Byte* cur = line_buff; /* current write cursor */ 123 FT_Int count = line_bits; /* # of bits to extract per line */ 124 FT_Byte shift = (FT_Byte)( x_offset & 7 ); /* current write shift */ 125 FT_Byte space = (FT_Byte)( 8 - shift ); 126 127 128 /* first of all, read individual source bytes */ 129 if ( count >= 8 ) 130 { 131 count -= 8; 132 { 133 do 134 { 135 FT_Byte val; 136 137 138 /* ensure that there are at least 8 bits in the accumulator */ 139 if ( loaded < 8 ) 140 { 141 acc |= (FT_UShort)((FT_UShort)*source++ << ( 8 - loaded )); 142 loaded += 8; 143 } 144 145 /* now write one byte */ 146 val = (FT_Byte)( acc >> 8 ); 147 if ( shift ) 148 { 149 cur[0] |= (FT_Byte)( val >> shift ); 150 cur[1] |= (FT_Byte)( val << space ); 151 } 152 else 153 cur[0] |= val; 154 155 cur++; 156 acc <<= 8; /* remove bits from accumulator */ 157 loaded -= 8; 158 count -= 8; 159 160 } while ( count >= 0 ); 161 } 162 163 /* restore `count' to correct value */ 164 count += 8; 165 } 166 167 /* now write remaining bits (count < 8) */ 168 if ( count > 0 ) 169 { 170 FT_Byte val; 171 172 173 /* ensure that there are at least `count' bits in the accumulator */ 174 if ( (FT_Int)loaded < count ) 175 { 176 acc |= (FT_UShort)((FT_UShort)*source++ << ( 8 - loaded )); 177 loaded += 8; 178 } 179 180 /* now write remaining bits */ 181 val = (FT_Byte)( ( (FT_Byte)( acc >> 8 ) ) & ~( 0xFF >> count ) ); 182 cur[0] |= (FT_Byte)( val >> shift ); 183 184 if ( count > space ) 185 cur[1] |= (FT_Byte)( val << space ); 186 187 acc <<= count; 188 loaded -= count; 189 } 190 191 /* now, skip to next line */ 192 if ( byte_padded ) 193 { 194 acc = 0; 195 loaded = 0; /* clear accumulator on byte-padded lines */ 196 } 197 198 line_buff += line_incr; 199 } 200 } 201 202 203 static const FT_Frame_Field sbit_metrics_fields[] = 204 { 205#undef FT_STRUCTURE 206#define FT_STRUCTURE TT_SBit_MetricsRec 207 208 FT_FRAME_START( 8 ), 209 FT_FRAME_BYTE( height ), 210 FT_FRAME_BYTE( width ), 211 212 FT_FRAME_CHAR( horiBearingX ), 213 FT_FRAME_CHAR( horiBearingY ), 214 FT_FRAME_BYTE( horiAdvance ), 215 216 FT_FRAME_CHAR( vertBearingX ), 217 FT_FRAME_CHAR( vertBearingY ), 218 FT_FRAME_BYTE( vertAdvance ), 219 FT_FRAME_END 220 }; 221 222 223 /*************************************************************************/ 224 /* */ 225 /* <Function> */ 226 /* Load_SBit_Const_Metrics */ 227 /* */ 228 /* <Description> */ 229 /* Loads the metrics for `EBLC' index tables format 2 and 5. */ 230 /* */ 231 /* <Input> */ 232 /* range :: The target range. */ 233 /* */ 234 /* stream :: The input stream. */ 235 /* */ 236 /* <Return> */ 237 /* FreeType error code. 0 means success. */ 238 /* */ 239 static FT_Error 240 Load_SBit_Const_Metrics( TT_SBit_Range range, 241 FT_Stream stream ) 242 { 243 FT_Error error; 244 245 246 if ( FT_READ_ULONG( range->image_size ) ) 247 return error; 248 249 return FT_STREAM_READ_FIELDS( sbit_metrics_fields, &range->metrics ); 250 } 251 252 253 /*************************************************************************/ 254 /* */ 255 /* <Function> */ 256 /* Load_SBit_Range_Codes */ 257 /* */ 258 /* <Description> */ 259 /* Loads the range codes for `EBLC' index tables format 4 and 5. */ 260 /* */ 261 /* <Input> */ 262 /* range :: The target range. */ 263 /* */ 264 /* stream :: The input stream. */ 265 /* */ 266 /* load_offsets :: A flag whether to load the glyph offset table. */ 267 /* */ 268 /* <Return> */ 269 /* FreeType error code. 0 means success. */ 270 /* */ 271 static FT_Error 272 Load_SBit_Range_Codes( TT_SBit_Range range, 273 FT_Stream stream, 274 FT_Bool load_offsets ) 275 { 276 FT_Error error; 277 FT_ULong count, n, size; 278 FT_Memory memory = stream->memory; 279 280 281 if ( FT_READ_ULONG( count ) ) 282 goto Exit; 283 284 range->num_glyphs = count; 285 286 /* Allocate glyph offsets table if needed */ 287 if ( load_offsets ) 288 { 289 if ( FT_NEW_ARRAY( range->glyph_offsets, count ) ) 290 goto Exit; 291 292 size = count * 4L; 293 } 294 else 295 size = count * 2L; 296 297 /* Allocate glyph codes table and access frame */ 298 if ( FT_NEW_ARRAY ( range->glyph_codes, count ) || 299 FT_FRAME_ENTER( size ) ) 300 goto Exit; 301 302 for ( n = 0; n < count; n++ ) 303 { 304 range->glyph_codes[n] = FT_GET_USHORT(); 305 306 if ( load_offsets ) 307 range->glyph_offsets[n] = (FT_ULong)range->image_offset + 308 FT_GET_USHORT(); 309 } 310 311 FT_FRAME_EXIT(); 312 313 Exit: 314 return error; 315 } 316 317 318 /*************************************************************************/ 319 /* */ 320 /* <Function> */ 321 /* Load_SBit_Range */ 322 /* */ 323 /* <Description> */ 324 /* Loads a given `EBLC' index/range table. */ 325 /* */ 326 /* <Input> */ 327 /* range :: The target range. */ 328 /* */ 329 /* stream :: The input stream. */ 330 /* */ 331 /* <Return> */ 332 /* FreeType error code. 0 means success. */ 333 /* */ 334 static FT_Error 335 Load_SBit_Range( TT_SBit_Range range, 336 FT_Stream stream ) 337 { 338 FT_Error error; 339 FT_Memory memory = stream->memory; 340 341 342 switch( range->index_format ) 343 { 344 case 1: /* variable metrics with 4-byte offsets */ 345 case 3: /* variable metrics with 2-byte offsets */ 346 { 347 FT_ULong num_glyphs, n; 348 FT_Int size_elem; 349 FT_Bool large = FT_BOOL( range->index_format == 1 ); 350 351 352 353 if ( range->last_glyph < range->first_glyph ) 354 { 355 error = SFNT_Err_Invalid_File_Format; 356 goto Exit; 357 } 358 359 num_glyphs = range->last_glyph - range->first_glyph + 1L; 360 range->num_glyphs = num_glyphs; 361 num_glyphs++; /* XXX: BEWARE - see spec */ 362 363 size_elem = large ? 4 : 2; 364 365 if ( FT_NEW_ARRAY( range->glyph_offsets, num_glyphs ) || 366 FT_FRAME_ENTER( num_glyphs * size_elem ) ) 367 goto Exit; 368 369 for ( n = 0; n < num_glyphs; n++ ) 370 range->glyph_offsets[n] = (FT_ULong)( range->image_offset + 371 ( large ? FT_GET_ULONG() 372 : FT_GET_USHORT() ) ); 373 FT_FRAME_EXIT(); 374 } 375 break; 376 377 case 2: /* all glyphs have identical metrics */ 378 error = Load_SBit_Const_Metrics( range, stream ); 379 break; 380 381 case 4: 382 error = Load_SBit_Range_Codes( range, stream, 1 ); 383 break; 384 385 case 5: 386 error = Load_SBit_Const_Metrics( range, stream ); 387 if ( !error ) 388 error = Load_SBit_Range_Codes( range, stream, 0 ); 389 break; 390 391 default: 392 error = SFNT_Err_Invalid_File_Format; 393 } 394 395 Exit: 396 return error; 397 } 398 399 400 /*************************************************************************/ 401 /* */ 402 /* <Function> */ 403 /* tt_face_load_eblc */ 404 /* */ 405 /* <Description> */ 406 /* Loads the table of embedded bitmap sizes for this face. */ 407 /* */ 408 /* <Input> */ 409 /* face :: The target face object. */ 410 /* */ 411 /* stream :: The input stream. */ 412 /* */ 413 /* <Return> */ 414 /* FreeType error code. 0 means success. */ 415 /* */ 416 FT_LOCAL_DEF( FT_Error ) 417 tt_face_load_eblc( TT_Face face, 418 FT_Stream stream ) 419 { 420 FT_Error error = 0; 421 FT_Memory memory = stream->memory; 422 FT_Fixed version; 423 FT_ULong num_strikes; 424 FT_ULong table_base; 425 426 static const FT_Frame_Field sbit_line_metrics_fields[] = 427 { 428#undef FT_STRUCTURE 429#define FT_STRUCTURE TT_SBit_LineMetricsRec 430 431 /* no FT_FRAME_START */ 432 FT_FRAME_CHAR( ascender ), 433 FT_FRAME_CHAR( descender ), 434 FT_FRAME_BYTE( max_width ), 435 436 FT_FRAME_CHAR( caret_slope_numerator ), 437 FT_FRAME_CHAR( caret_slope_denominator ), 438 FT_FRAME_CHAR( caret_offset ), 439 440 FT_FRAME_CHAR( min_origin_SB ), 441 FT_FRAME_CHAR( min_advance_SB ), 442 FT_FRAME_CHAR( max_before_BL ), 443 FT_FRAME_CHAR( min_after_BL ), 444 FT_FRAME_CHAR( pads[0] ), 445 FT_FRAME_CHAR( pads[1] ), 446 FT_FRAME_END 447 }; 448 449 static const FT_Frame_Field strike_start_fields[] = 450 { 451#undef FT_STRUCTURE 452#define FT_STRUCTURE TT_SBit_StrikeRec 453 454 /* no FT_FRAME_START */ 455 FT_FRAME_ULONG( ranges_offset ), 456 FT_FRAME_SKIP_LONG, 457 FT_FRAME_ULONG( num_ranges ), 458 FT_FRAME_ULONG( color_ref ), 459 FT_FRAME_END 460 }; 461 462 static const FT_Frame_Field strike_end_fields[] = 463 { 464 /* no FT_FRAME_START */ 465 FT_FRAME_USHORT( start_glyph ), 466 FT_FRAME_USHORT( end_glyph ), 467 FT_FRAME_BYTE ( x_ppem ), 468 FT_FRAME_BYTE ( y_ppem ), 469 FT_FRAME_BYTE ( bit_depth ), 470 FT_FRAME_CHAR ( flags ), 471 FT_FRAME_END 472 }; 473 474 475 face->num_sbit_strikes = 0; 476 477 /* this table is optional */ 478 error = face->goto_table( face, TTAG_EBLC, stream, 0 ); 479 if ( error ) 480 error = face->goto_table( face, TTAG_bloc, stream, 0 ); 481 if ( error ) 482 goto Exit; 483 484 table_base = FT_STREAM_POS(); 485 if ( FT_FRAME_ENTER( 8L ) ) 486 goto Exit; 487 488 version = FT_GET_LONG(); 489 num_strikes = FT_GET_ULONG(); 490 491 FT_FRAME_EXIT(); 492 493 /* check version number and strike count */ 494 if ( version != 0x00020000L || 495 num_strikes >= 0x10000L ) 496 { 497 FT_ERROR(( "tt_face_load_sbit_strikes: invalid table version!\n" )); 498 error = SFNT_Err_Invalid_File_Format; 499 500 goto Exit; 501 } 502 503 /* allocate the strikes table */ 504 if ( FT_NEW_ARRAY( face->sbit_strikes, num_strikes ) ) 505 goto Exit; 506 507 face->num_sbit_strikes = num_strikes; 508 509 /* now read each strike table separately */ 510 { 511 TT_SBit_Strike strike = face->sbit_strikes; 512 FT_ULong count = num_strikes; 513 514 515 if ( FT_FRAME_ENTER( 48L * num_strikes ) ) 516 goto Exit; 517 518 while ( count > 0 ) 519 { 520 if ( FT_STREAM_READ_FIELDS( strike_start_fields, strike ) || 521 FT_STREAM_READ_FIELDS( sbit_line_metrics_fields, &strike->hori ) || 522 FT_STREAM_READ_FIELDS( sbit_line_metrics_fields, &strike->vert ) || 523 FT_STREAM_READ_FIELDS( strike_end_fields, strike ) ) 524 break; 525 526 count--; 527 strike++; 528 } 529 530 FT_FRAME_EXIT(); 531 } 532 533 /* allocate the index ranges for each strike table */ 534 { 535 TT_SBit_Strike strike = face->sbit_strikes; 536 FT_ULong count = num_strikes; 537 538 539 while ( count > 0 ) 540 { 541 TT_SBit_Range range; 542 FT_ULong count2 = strike->num_ranges; 543 544 545 /* read each range */ 546 if ( FT_STREAM_SEEK( table_base + strike->ranges_offset ) || 547 FT_FRAME_ENTER( strike->num_ranges * 8L ) ) 548 goto Exit; 549 550 if ( FT_NEW_ARRAY( strike->sbit_ranges, strike->num_ranges ) ) 551 goto Exit; 552 553 range = strike->sbit_ranges; 554 while ( count2 > 0 ) 555 { 556 range->first_glyph = FT_GET_USHORT(); 557 range->last_glyph = FT_GET_USHORT(); 558 range->table_offset = table_base + strike->ranges_offset + 559 FT_GET_ULONG(); 560 count2--; 561 range++; 562 } 563 564 FT_FRAME_EXIT(); 565 566 /* Now, read each index table */ 567 count2 = strike->num_ranges; 568 range = strike->sbit_ranges; 569 while ( count2 > 0 ) 570 { 571 /* Read the header */ 572 if ( FT_STREAM_SEEK( range->table_offset ) || 573 FT_FRAME_ENTER( 8L ) ) 574 goto Exit; 575 576 range->index_format = FT_GET_USHORT(); 577 range->image_format = FT_GET_USHORT(); 578 range->image_offset = FT_GET_ULONG(); 579 580 FT_FRAME_EXIT(); 581 582 error = Load_SBit_Range( range, stream ); 583 if ( error ) 584 goto Exit; 585 586 count2--; 587 range++; 588 } 589 590 count--; 591 strike++; 592 } 593 } 594 595 Exit: 596 return error; 597 } 598 599 600 /*************************************************************************/ 601 /* */ 602 /* <Function> */ 603 /* tt_face_free_eblc */ 604 /* */ 605 /* <Description> */ 606 /* Releases the embedded bitmap tables. */ 607 /* */ 608 /* <Input> */ 609 /* face :: The target face object. */ 610 /* */ 611 FT_LOCAL_DEF( void ) 612 tt_face_free_eblc( TT_Face face ) 613 { 614 FT_Memory memory = face->root.memory; 615 TT_SBit_Strike strike = face->sbit_strikes; 616 TT_SBit_Strike strike_limit = strike + face->num_sbit_strikes; 617 618 619 if ( strike ) 620 { 621 for ( ; strike < strike_limit; strike++ ) 622 { 623 TT_SBit_Range range = strike->sbit_ranges; 624 TT_SBit_Range range_limit = range + strike->num_ranges; 625 626 627 if ( range ) 628 { 629 for ( ; range < range_limit; range++ ) 630 { 631 /* release the glyph offsets and codes tables */ 632 /* where appropriate */ 633 FT_FREE( range->glyph_offsets ); 634 FT_FREE( range->glyph_codes ); 635 } 636 } 637 FT_FREE( strike->sbit_ranges ); 638 strike->num_ranges = 0; 639 } 640 FT_FREE( face->sbit_strikes ); 641 } 642 face->num_sbit_strikes = 0; 643 } 644 645 646 FT_LOCAL_DEF( FT_Error ) 647 tt_face_set_sbit_strike( TT_Face face, 648 FT_Size_Request req, 649 FT_ULong* astrike_index ) 650 { 651 return FT_Match_Size( (FT_Face)face, req, 0, astrike_index ); 652 } 653 654 655 FT_LOCAL_DEF( FT_Error ) 656 tt_face_load_strike_metrics( TT_Face face, 657 FT_ULong strike_index, 658 FT_Size_Metrics* metrics ) 659 { 660 TT_SBit_Strike strike; 661 662 663 if ( strike_index >= face->num_sbit_strikes ) 664 return SFNT_Err_Invalid_Argument; 665 666 strike = face->sbit_strikes + strike_index; 667 668 metrics->x_ppem = strike->x_ppem; 669 metrics->y_ppem = strike->y_ppem; 670 671 metrics->ascender = strike->hori.ascender << 6; 672 metrics->descender = strike->hori.descender << 6; 673 674 /* XXX: Is this correct? */ 675 metrics->max_advance = ( strike->hori.min_origin_SB + 676 strike->hori.max_width + 677 strike->hori.min_advance_SB ) << 6; 678 679 metrics->height = metrics->ascender - metrics->descender; 680 681 return SFNT_Err_Ok; 682 } 683 684 685 /*************************************************************************/ 686 /* */ 687 /* <Function> */ 688 /* find_sbit_range */ 689 /* */ 690 /* <Description> */ 691 /* Scans a given strike's ranges and return, for a given glyph */ 692 /* index, the corresponding sbit range, and `EBDT' offset. */ 693 /* */ 694 /* <Input> */ 695 /* glyph_index :: The glyph index. */ 696 /* */ 697 /* strike :: The source/current sbit strike. */ 698 /* */ 699 /* <Output> */ 700 /* arange :: The sbit range containing the glyph index. */ 701 /* */ 702 /* aglyph_offset :: The offset of the glyph data in `EBDT' table. */ 703 /* */ 704 /* <Return> */ 705 /* FreeType error code. 0 means the glyph index was found. */ 706 /* */ 707 static FT_Error 708 find_sbit_range( FT_UInt glyph_index, 709 TT_SBit_Strike strike, 710 TT_SBit_Range *arange, 711 FT_ULong *aglyph_offset ) 712 { 713 TT_SBit_RangeRec *range, *range_limit; 714 715 716 /* check whether the glyph index is within this strike's */ 717 /* glyph range */ 718 if ( glyph_index < (FT_UInt)strike->start_glyph || 719 glyph_index > (FT_UInt)strike->end_glyph ) 720 goto Fail; 721 722 /* scan all ranges in strike */ 723 range = strike->sbit_ranges; 724 range_limit = range + strike->num_ranges; 725 if ( !range ) 726 goto Fail; 727 728 for ( ; range < range_limit; range++ ) 729 { 730 if ( glyph_index >= (FT_UInt)range->first_glyph && 731 glyph_index <= (FT_UInt)range->last_glyph ) 732 { 733 FT_UShort delta = (FT_UShort)( glyph_index - range->first_glyph ); 734 735 736 switch ( range->index_format ) 737 { 738 case 1: 739 case 3: 740 *aglyph_offset = range->glyph_offsets[delta]; 741 break; 742 743 case 2: 744 *aglyph_offset = range->image_offset + 745 range->image_size * delta; 746 break; 747 748 case 4: 749 case 5: 750 { 751 FT_ULong n; 752 753 754 for ( n = 0; n < range->num_glyphs; n++ ) 755 { 756 if ( (FT_UInt)range->glyph_codes[n] == glyph_index ) 757 { 758 if ( range->index_format == 4 ) 759 *aglyph_offset = range->glyph_offsets[n]; 760 else 761 *aglyph_offset = range->image_offset + 762 n * range->image_size; 763 goto Found; 764 } 765 } 766 } 767 768 /* fall-through */ 769 default: 770 goto Fail; 771 } 772 773 Found: 774 /* return successfully! */ 775 *arange = range; 776 return SFNT_Err_Ok; 777 } 778 } 779 780 Fail: 781 *arange = 0; 782 *aglyph_offset = 0; 783 784 return SFNT_Err_Invalid_Argument; 785 } 786 787 788 /*************************************************************************/ 789 /* */ 790 /* <Function> */ 791 /* tt_find_sbit_image */ 792 /* */ 793 /* <Description> */ 794 /* Checks whether an embedded bitmap (an `sbit') exists for a given */ 795 /* glyph, at a given strike. */ 796 /* */ 797 /* <Input> */ 798 /* face :: The target face object. */ 799 /* */ 800 /* glyph_index :: The glyph index. */ 801 /* */ 802 /* strike_index :: The current strike index. */ 803 /* */ 804 /* <Output> */ 805 /* arange :: The SBit range containing the glyph index. */ 806 /* */ 807 /* astrike :: The SBit strike containing the glyph index. */ 808 /* */ 809 /* aglyph_offset :: The offset of the glyph data in `EBDT' table. */ 810 /* */ 811 /* <Return> */ 812 /* FreeType error code. 0 means success. Returns */ 813 /* SFNT_Err_Invalid_Argument if no sbit exists for the requested */ 814 /* glyph. */ 815 /* */ 816 FT_LOCAL( FT_Error ) 817 tt_find_sbit_image( TT_Face face, 818 FT_UInt glyph_index, 819 FT_ULong strike_index, 820 TT_SBit_Range *arange, 821 TT_SBit_Strike *astrike, 822 FT_ULong *aglyph_offset ) 823 { 824 FT_Error error; 825 TT_SBit_Strike strike; 826 827 828 if ( !face->sbit_strikes || 829 ( face->num_sbit_strikes <= strike_index ) ) 830 goto Fail; 831 832 strike = &face->sbit_strikes[strike_index]; 833 834 error = find_sbit_range( glyph_index, strike, 835 arange, aglyph_offset ); 836 if ( error ) 837 goto Fail; 838 839 *astrike = strike; 840 841 return SFNT_Err_Ok; 842 843 Fail: 844 /* no embedded bitmap for this glyph in face */ 845 *arange = 0; 846 *astrike = 0; 847 *aglyph_offset = 0; 848 849 return SFNT_Err_Invalid_Argument; 850 } 851 852 853 /*************************************************************************/ 854 /* */ 855 /* <Function> */ 856 /* tt_load_sbit_metrics */ 857 /* */ 858 /* <Description> */ 859 /* Gets the big metrics for a given SBit. */ 860 /* */ 861 /* <Input> */ 862 /* stream :: The input stream. */ 863 /* */ 864 /* range :: The SBit range containing the glyph. */ 865 /* */ 866 /* <Output> */ 867 /* big_metrics :: A big SBit metrics structure for the glyph. */ 868 /* */ 869 /* <Return> */ 870 /* FreeType error code. 0 means success. */ 871 /* */ 872 /* <Note> */ 873 /* The stream cursor must be positioned at the glyph's offset within */ 874 /* the `EBDT' table before the call. */ 875 /* */ 876 /* If the image format uses variable metrics, the stream cursor is */ 877 /* positioned just after the metrics header in the `EBDT' table on */ 878 /* function exit. */ 879 /* */ 880 FT_LOCAL( FT_Error ) 881 tt_load_sbit_metrics( FT_Stream stream, 882 TT_SBit_Range range, 883 TT_SBit_Metrics metrics ) 884 { 885 FT_Error error = SFNT_Err_Ok; 886 887 888 switch ( range->image_format ) 889 { 890 case 1: 891 case 2: 892 case 8: 893 /* variable small metrics */ 894 { 895 TT_SBit_SmallMetricsRec smetrics; 896 897 static const FT_Frame_Field sbit_small_metrics_fields[] = 898 { 899#undef FT_STRUCTURE 900#define FT_STRUCTURE TT_SBit_SmallMetricsRec 901 902 FT_FRAME_START( 5 ), 903 FT_FRAME_BYTE( height ), 904 FT_FRAME_BYTE( width ), 905 FT_FRAME_CHAR( bearingX ), 906 FT_FRAME_CHAR( bearingY ), 907 FT_FRAME_BYTE( advance ), 908 FT_FRAME_END 909 }; 910 911 912 /* read small metrics */ 913 if ( FT_STREAM_READ_FIELDS( sbit_small_metrics_fields, &smetrics ) ) 914 goto Exit; 915 916 /* convert it to a big metrics */ 917 metrics->height = smetrics.height; 918 metrics->width = smetrics.width; 919 metrics->horiBearingX = smetrics.bearingX; 920 metrics->horiBearingY = smetrics.bearingY; 921 metrics->horiAdvance = smetrics.advance; 922 923 /* these metrics are made up at a higher level when */ 924 /* needed. */ 925 metrics->vertBearingX = 0; 926 metrics->vertBearingY = 0; 927 metrics->vertAdvance = 0; 928 } 929 break; 930 931 case 6: 932 case 7: 933 case 9: 934 /* variable big metrics */ 935 if ( FT_STREAM_READ_FIELDS( sbit_metrics_fields, metrics ) ) 936 goto Exit; 937 break; 938 939 case 5: 940 default: /* constant metrics */ 941 if ( range->index_format == 2 || range->index_format == 5 ) 942 *metrics = range->metrics; 943 else 944 return SFNT_Err_Invalid_File_Format; 945 } 946 947 Exit: 948 return error; 949 } 950 951 952 /*************************************************************************/ 953 /* */ 954 /* <Function> */ 955 /* crop_bitmap */ 956 /* */ 957 /* <Description> */ 958 /* Crops a bitmap to its tightest bounding box, and adjusts its */ 959 /* metrics. */ 960 /* */ 961 /* <InOut> */ 962 /* map :: The bitmap. */ 963 /* */ 964 /* metrics :: The corresponding metrics structure. */ 965 /* */ 966 static void 967 crop_bitmap( FT_Bitmap* map, 968 TT_SBit_Metrics metrics ) 969 { 970 /***********************************************************************/ 971 /* */ 972 /* In this situation, some bounding boxes of embedded bitmaps are too */ 973 /* large. We need to crop it to a reasonable size. */ 974 /* */ 975 /* --------- */ 976 /* | | ----- */ 977 /* | *** | |***| */ 978 /* | * | | * | */ 979 /* | * | ------> | * | */ 980 /* | * | | * | */ 981 /* | * | | * | */ 982 /* | *** | |***| */ 983 /* --------- ----- */ 984 /* */ 985 /***********************************************************************/ 986 987 FT_Int rows, count; 988 FT_Long line_len; 989 FT_Byte* line; 990 991 992 /***********************************************************************/ 993 /* */ 994 /* first of all, check the top-most lines of the bitmap, and remove */ 995 /* them if they're empty. */ 996 /* */ 997 { 998 line = (FT_Byte*)map->buffer; 999 rows = map->rows; 1000 line_len = map->pitch; 1001 1002 1003 for ( count = 0; count < rows; count++ ) 1004 { 1005 FT_Byte* cur = line; 1006 FT_Byte* limit = line + line_len; 1007 1008 1009 for ( ; cur < limit; cur++ ) 1010 if ( cur[0] ) 1011 goto Found_Top; 1012 1013 /* the current line was empty - skip to next one */ 1014 line = limit; 1015 } 1016 1017 Found_Top: 1018 /* check that we have at least one filled line */ 1019 if ( count >= rows ) 1020 goto Empty_Bitmap; 1021 1022 /* now, crop the empty upper lines */ 1023 if ( count > 0 ) 1024 { 1025 line = (FT_Byte*)map->buffer; 1026 1027 FT_MEM_MOVE( line, line + count * line_len, 1028 ( rows - count ) * line_len ); 1029 1030 metrics->height = (FT_Byte)( metrics->height - count ); 1031 metrics->horiBearingY = (FT_Char)( metrics->horiBearingY - count ); 1032 metrics->vertBearingY = (FT_Char)( metrics->vertBearingY - count ); 1033 1034 map->rows -= count; 1035 rows -= count; 1036 } 1037 } 1038 1039 /***********************************************************************/ 1040 /* */ 1041 /* second, crop the lower lines */ 1042 /* */ 1043 { 1044 line = (FT_Byte*)map->buffer + ( rows - 1 ) * line_len; 1045 1046 for ( count = 0; count < rows; count++ ) 1047 { 1048 FT_Byte* cur = line; 1049 FT_Byte* limit = line + line_len; 1050 1051 1052 for ( ; cur < limit; cur++ ) 1053 if ( cur[0] ) 1054 goto Found_Bottom; 1055 1056 /* the current line was empty - skip to previous one */ 1057 line -= line_len; 1058 } 1059 1060 Found_Bottom: 1061 if ( count > 0 ) 1062 { 1063 metrics->height = (FT_Byte)( metrics->height - count ); 1064 rows -= count; 1065 map->rows -= count; 1066 } 1067 } 1068 1069 /***********************************************************************/ 1070 /* */ 1071 /* third, get rid of the space on the left side of the glyph */ 1072 /* */ 1073 do 1074 { 1075 FT_Byte* limit; 1076 1077 1078 line = (FT_Byte*)map->buffer; 1079 limit = line + rows * line_len; 1080 1081 for ( ; line < limit; line += line_len ) 1082 if ( line[0] & 0x80 ) 1083 goto Found_Left; 1084 1085 /* shift the whole glyph one pixel to the left */ 1086 line = (FT_Byte*)map->buffer; 1087 limit = line + rows * line_len; 1088 1089 for ( ; line < limit; line += line_len ) 1090 { 1091 FT_Int n, width = map->width; 1092 FT_Byte old; 1093 FT_Byte* cur = line; 1094 1095 1096 old = (FT_Byte)(cur[0] << 1); 1097 for ( n = 8; n < width; n += 8 ) 1098 { 1099 FT_Byte val; 1100 1101 1102 val = cur[1]; 1103 cur[0] = (FT_Byte)( old | ( val >> 7 ) ); 1104 old = (FT_Byte)( val << 1 ); 1105 cur++; 1106 } 1107 cur[0] = old; 1108 } 1109 1110 map->width--; 1111 metrics->horiBearingX++; 1112 metrics->vertBearingX++; 1113 metrics->width--; 1114 1115 } while ( map->width > 0 ); 1116 1117 Found_Left: 1118 1119 /***********************************************************************/ 1120 /* */ 1121 /* finally, crop the bitmap width to get rid of the space on the right */ 1122 /* side of the glyph. */ 1123 /* */ 1124 do 1125 { 1126 FT_Int right = map->width - 1; 1127 FT_Byte* limit; 1128 FT_Byte mask; 1129 1130 1131 line = (FT_Byte*)map->buffer + ( right >> 3 ); 1132 limit = line + rows * line_len; 1133 mask = (FT_Byte)( 0x80 >> ( right & 7 ) ); 1134 1135 for ( ; line < limit; line += line_len ) 1136 if ( line[0] & mask ) 1137 goto Found_Right; 1138 1139 /* crop the whole glyph to the right */ 1140 map->width--; 1141 metrics->width--; 1142 1143 } while ( map->width > 0 ); 1144 1145 Found_Right: 1146 /* all right, the bitmap was cropped */ 1147 return; 1148 1149 Empty_Bitmap: 1150 map->width = 0; 1151 map->rows = 0; 1152 map->pitch = 0; 1153 map->pixel_mode = FT_PIXEL_MODE_MONO; 1154 } 1155 1156 1157 static FT_Error 1158 Load_SBit_Single( FT_Bitmap* map, 1159 FT_Int x_offset, 1160 FT_Int y_offset, 1161 FT_Int pix_bits, 1162 FT_UShort image_format, 1163 TT_SBit_Metrics metrics, 1164 FT_Stream stream ) 1165 { 1166 FT_Error error; 1167 1168 1169 /* check that the source bitmap fits into the target pixmap */ 1170 if ( x_offset < 0 || x_offset + metrics->width > map->width || 1171 y_offset < 0 || y_offset + metrics->height > map->rows ) 1172 { 1173 error = SFNT_Err_Invalid_Argument; 1174 1175 goto Exit; 1176 } 1177 1178 { 1179 FT_Int glyph_width = metrics->width; 1180 FT_Int glyph_height = metrics->height; 1181 FT_Int glyph_size; 1182 FT_Int line_bits = pix_bits * glyph_width; 1183 FT_Bool pad_bytes = 0; 1184 1185 1186 /* compute size of glyph image */ 1187 switch ( image_format ) 1188 { 1189 case 1: /* byte-padded formats */ 1190 case 6: 1191 { 1192 FT_Int line_length; 1193 1194 1195 switch ( pix_bits ) 1196 { 1197 case 1: 1198 line_length = ( glyph_width + 7 ) >> 3; 1199 break; 1200 case 2: 1201 line_length = ( glyph_width + 3 ) >> 2; 1202 break; 1203 case 4: 1204 line_length = ( glyph_width + 1 ) >> 1; 1205 break; 1206 default: 1207 line_length = glyph_width; 1208 } 1209 1210 glyph_size = glyph_height * line_length; 1211 pad_bytes = 1; 1212 } 1213 break; 1214 1215 case 2: 1216 case 5: 1217 case 7: 1218 line_bits = glyph_width * pix_bits; 1219 glyph_size = ( glyph_height * line_bits + 7 ) >> 3; 1220 break; 1221 1222 default: /* invalid format */ 1223 return SFNT_Err_Invalid_File_Format; 1224 } 1225 1226 /* Now read data and draw glyph into target pixmap */ 1227 if ( FT_FRAME_ENTER( glyph_size ) ) 1228 goto Exit; 1229 1230 /* don't forget to multiply `x_offset' by `map->pix_bits' as */ 1231 /* the sbit blitter doesn't make a difference between pixmap */ 1232 /* depths. */ 1233 blit_sbit( map, (FT_Byte*)stream->cursor, line_bits, pad_bytes, 1234 x_offset * pix_bits, y_offset, metrics->height ); 1235 1236 FT_FRAME_EXIT(); 1237 } 1238 1239 Exit: 1240 return error; 1241 } 1242 1243 1244 static FT_Error 1245 Load_SBit_Image( TT_SBit_Strike strike, 1246 TT_SBit_Range range, 1247 FT_ULong ebdt_pos, 1248 FT_ULong glyph_offset, 1249 FT_GlyphSlot slot, 1250 FT_Int x_offset, 1251 FT_Int y_offset, 1252 FT_Stream stream, 1253 TT_SBit_Metrics metrics, 1254 FT_Int depth ) 1255 { 1256 FT_Memory memory = stream->memory; 1257 FT_Bitmap* map = &slot->bitmap; 1258 FT_Error error; 1259 1260 1261 /* place stream at beginning of glyph data and read metrics */ 1262 if ( FT_STREAM_SEEK( ebdt_pos + glyph_offset ) ) 1263 goto Exit; 1264 1265 error = tt_load_sbit_metrics( stream, range, metrics ); 1266 if ( error ) 1267 goto Exit; 1268 1269 /* This function is recursive. At the top-level call, we */ 1270 /* compute the dimensions of the higher-level glyph to */ 1271 /* allocate the final pixmap buffer. */ 1272 if ( depth == 0 ) 1273 { 1274 FT_Long size; 1275 1276 1277 map->width = metrics->width; 1278 map->rows = metrics->height; 1279 1280 switch ( strike->bit_depth ) 1281 { 1282 case 1: 1283 map->pixel_mode = FT_PIXEL_MODE_MONO; 1284 map->pitch = ( map->width + 7 ) >> 3; 1285 break; 1286 1287 case 2: 1288 map->pixel_mode = FT_PIXEL_MODE_GRAY2; 1289 map->pitch = ( map->width + 3 ) >> 2; 1290 break; 1291 1292 case 4: 1293 map->pixel_mode = FT_PIXEL_MODE_GRAY4; 1294 map->pitch = ( map->width + 1 ) >> 1; 1295 break; 1296 1297 case 8: 1298 map->pixel_mode = FT_PIXEL_MODE_GRAY; 1299 map->pitch = map->width; 1300 break; 1301 1302 default: 1303 return SFNT_Err_Invalid_File_Format; 1304 } 1305 1306 size = map->rows * map->pitch; 1307 1308 /* check that there is no empty image */ 1309 if ( size == 0 ) 1310 goto Exit; /* exit successfully! */ 1311 1312 error = ft_glyphslot_alloc_bitmap( slot, size ); 1313 if (error) 1314 goto Exit; 1315 } 1316 1317 switch ( range->image_format ) 1318 { 1319 case 1: /* single sbit image - load it */ 1320 case 2: 1321 case 5: 1322 case 6: 1323 case 7: 1324 return Load_SBit_Single( map, x_offset, y_offset, strike->bit_depth, 1325 range->image_format, metrics, stream ); 1326 1327 case 8: /* compound format */ 1328 if ( FT_STREAM_SKIP( 1L ) ) 1329 { 1330 error = SFNT_Err_Invalid_Stream_Skip; 1331 goto Exit; 1332 } 1333 /* fallthrough */ 1334 1335 case 9: 1336 break; 1337 1338 default: /* invalid image format */ 1339 return SFNT_Err_Invalid_File_Format; 1340 } 1341 1342 /* All right, we have a compound format. First of all, read */ 1343 /* the array of elements. */ 1344 { 1345 TT_SBit_Component components; 1346 TT_SBit_Component comp; 1347 FT_UShort num_components, count; 1348 1349 1350 if ( FT_READ_USHORT( num_components ) || 1351 FT_NEW_ARRAY( components, num_components ) ) 1352 goto Exit; 1353 1354 count = num_components; 1355 1356 if ( FT_FRAME_ENTER( 4L * num_components ) ) 1357 goto Fail_Memory; 1358 1359 for ( comp = components; count > 0; count--, comp++ ) 1360 { 1361 comp->glyph_code = FT_GET_USHORT(); 1362 comp->x_offset = FT_GET_CHAR(); 1363 comp->y_offset = FT_GET_CHAR(); 1364 } 1365 1366 FT_FRAME_EXIT(); 1367 1368 /* Now recursively load each element glyph */ 1369 count = num_components; 1370 comp = components; 1371 for ( ; count > 0; count--, comp++ ) 1372 { 1373 TT_SBit_Range elem_range; 1374 TT_SBit_MetricsRec elem_metrics; 1375 FT_ULong elem_offset; 1376 1377 1378 /* find the range for this element */ 1379 error = find_sbit_range( comp->glyph_code, 1380 strike, 1381 &elem_range, 1382 &elem_offset ); 1383 if ( error ) 1384 goto Fail_Memory; 1385 1386 /* now load the element, recursively */ 1387 error = Load_SBit_Image( strike, 1388 elem_range, 1389 ebdt_pos, 1390 elem_offset, 1391 slot, 1392 x_offset + comp->x_offset, 1393 y_offset + comp->y_offset, 1394 stream, 1395 &elem_metrics, 1396 depth + 1 ); 1397 if ( error ) 1398 goto Fail_Memory; 1399 } 1400 1401 Fail_Memory: 1402 FT_FREE( components ); 1403 } 1404 1405 Exit: 1406 return error; 1407 } 1408 1409 1410 /*************************************************************************/ 1411 /* */ 1412 /* <Function> */ 1413 /* tt_face_load_sbit_image */ 1414 /* */ 1415 /* <Description> */ 1416 /* Loads a given glyph sbit image from the font resource. This also */ 1417 /* returns its metrics. */ 1418 /* */ 1419 /* <Input> */ 1420 /* face :: The target face object. */ 1421 /* */ 1422 /* strike_index :: The current strike index. */ 1423 /* */ 1424 /* glyph_index :: The current glyph index. */ 1425 /* */ 1426 /* load_flags :: The glyph load flags (the code checks for the flag */ 1427 /* FT_LOAD_CROP_BITMAP). */ 1428 /* */ 1429 /* stream :: The input stream. */ 1430 /* */ 1431 /* <Output> */ 1432 /* map :: The target pixmap. */ 1433 /* */ 1434 /* metrics :: A big sbit metrics structure for the glyph image. */ 1435 /* */ 1436 /* <Return> */ 1437 /* FreeType error code. 0 means success. Returns an error if no */ 1438 /* glyph sbit exists for the index. */ 1439 /* */ 1440 /* <Note> */ 1441 /* The `map.buffer' field is always freed before the glyph is loaded. */ 1442 /* */ 1443 FT_LOCAL_DEF( FT_Error ) 1444 tt_face_load_sbit_image( TT_Face face, 1445 FT_ULong strike_index, 1446 FT_UInt glyph_index, 1447 FT_UInt load_flags, 1448 FT_Stream stream, 1449 FT_Bitmap *map, 1450 TT_SBit_MetricsRec *metrics ) 1451 { 1452 FT_Error error; 1453 FT_ULong ebdt_pos, glyph_offset; 1454 1455 TT_SBit_Strike strike; 1456 TT_SBit_Range range; 1457 1458 1459 /* Check whether there is a glyph sbit for the current index */ 1460 error = tt_find_sbit_image( face, glyph_index, strike_index, 1461 &range, &strike, &glyph_offset ); 1462 if ( error ) 1463 goto Exit; 1464 1465 /* now, find the location of the `EBDT' table in */ 1466 /* the font file */ 1467 error = face->goto_table( face, TTAG_EBDT, stream, 0 ); 1468 if ( error ) 1469 error = face->goto_table( face, TTAG_bdat, stream, 0 ); 1470 if ( error ) 1471 goto Exit; 1472 1473 ebdt_pos = FT_STREAM_POS(); 1474 1475 error = Load_SBit_Image( strike, range, ebdt_pos, glyph_offset, 1476 face->root.glyph, 0, 0, stream, metrics, 0 ); 1477 if ( error ) 1478 goto Exit; 1479 1480 /* setup vertical metrics if needed */ 1481 if ( strike->flags & 1 ) 1482 { 1483 /* in case of a horizontal strike only */ 1484 FT_Int advance; 1485 1486 1487 advance = strike->hori.ascender - strike->hori.descender; 1488 1489 /* some heuristic values */ 1490 1491 metrics->vertBearingX = (FT_Char)(-metrics->width / 2 ); 1492 metrics->vertBearingY = (FT_Char)( ( advance - metrics->height ) / 2 ); 1493 metrics->vertAdvance = (FT_Char)( advance * 12 / 10 ); 1494 } 1495 1496 /* Crop the bitmap now, unless specified otherwise */ 1497 if ( load_flags & FT_LOAD_CROP_BITMAP ) 1498 crop_bitmap( map, metrics ); 1499 1500 Exit: 1501 return error; 1502 } 1503 1504#endif /* FT_CONFIG_OPTION_OLD_INTERNALS */ 1505 1506 1507/* END */ 1508