1 /***************************************************************************/ 2 /* */ 3 /* afcjk.c */ 4 /* */ 5 /* Auto-fitter hinting routines for CJK script (body). */ 6 /* */ 7 /* Copyright 2006, 2007, 2008, 2009, 2010 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 * The algorithm is based on akito's autohint patch, available here: 20 * 21 * http://www.kde.gr.jp/~akito/patch/freetype2/ 22 * 23 */ 24 25 #include "aftypes.h" 26 #include "aflatin.h" 27 28 29 #ifdef AF_CONFIG_OPTION_CJK 30 31 #include "afcjk.h" 32 #include "aferrors.h" 33 34 35 #ifdef AF_USE_WARPER 36 #include "afwarp.h" 37 #endif 38 39 40 /*************************************************************************/ 41 /*************************************************************************/ 42 /***** *****/ 43 /***** C J K G L O B A L M E T R I C S *****/ 44 /***** *****/ 45 /*************************************************************************/ 46 /*************************************************************************/ 47 48 FT_LOCAL_DEF( FT_Error ) 49 af_cjk_metrics_init( AF_LatinMetrics metrics, 50 FT_Face face ) 51 { 52 FT_CharMap oldmap = face->charmap; 53 54 55 metrics->units_per_em = face->units_per_EM; 56 57 /* TODO are there blues? */ 58 59 if ( FT_Select_Charmap( face, FT_ENCODING_UNICODE ) ) 60 face->charmap = NULL; 61 else 62 { 63 /* latin's version would suffice */ 64 af_latin_metrics_init_widths( metrics, face, 0x7530 ); 65 af_latin_metrics_check_digits( metrics, face ); 66 } 67 68 FT_Set_Charmap( face, oldmap ); 69 70 return AF_Err_Ok; 71 } 72 73 74 static void 75 af_cjk_metrics_scale_dim( AF_LatinMetrics metrics, 76 AF_Scaler scaler, 77 AF_Dimension dim ) 78 { 79 AF_LatinAxis axis; 80 81 82 axis = &metrics->axis[dim]; 83 84 if ( dim == AF_DIMENSION_HORZ ) 85 { 86 axis->scale = scaler->x_scale; 87 axis->delta = scaler->x_delta; 88 } 89 else 90 { 91 axis->scale = scaler->y_scale; 92 axis->delta = scaler->y_delta; 93 } 94 } 95 96 97 FT_LOCAL_DEF( void ) 98 af_cjk_metrics_scale( AF_LatinMetrics metrics, 99 AF_Scaler scaler ) 100 { 101 metrics->root.scaler = *scaler; 102 103 af_cjk_metrics_scale_dim( metrics, scaler, AF_DIMENSION_HORZ ); 104 af_cjk_metrics_scale_dim( metrics, scaler, AF_DIMENSION_VERT ); 105 } 106 107 108 /*************************************************************************/ 109 /*************************************************************************/ 110 /***** *****/ 111 /***** C J K G L Y P H A N A L Y S I S *****/ 112 /***** *****/ 113 /*************************************************************************/ 114 /*************************************************************************/ 115 116 static FT_Error 117 af_cjk_hints_compute_segments( AF_GlyphHints hints, 118 AF_Dimension dim ) 119 { 120 AF_AxisHints axis = &hints->axis[dim]; 121 AF_Segment segments = axis->segments; 122 AF_Segment segment_limit = segments + axis->num_segments; 123 FT_Error error; 124 AF_Segment seg; 125 126 127 error = af_latin_hints_compute_segments( hints, dim ); 128 if ( error ) 129 return error; 130 131 /* a segment is round if it doesn't have successive */ 132 /* on-curve points. */ 133 for ( seg = segments; seg < segment_limit; seg++ ) 134 { 135 AF_Point pt = seg->first; 136 AF_Point last = seg->last; 137 AF_Flags f0 = (AF_Flags)(pt->flags & AF_FLAG_CONTROL); 138 AF_Flags f1; 139 140 141 seg->flags &= ~AF_EDGE_ROUND; 142 143 for ( ; pt != last; f0 = f1 ) 144 { 145 pt = pt->next; 146 f1 = (AF_Flags)(pt->flags & AF_FLAG_CONTROL); 147 148 if ( !f0 && !f1 ) 149 break; 150 151 if ( pt == last ) 152 seg->flags |= AF_EDGE_ROUND; 153 } 154 } 155 156 return AF_Err_Ok; 157 } 158 159 160 static void 161 af_cjk_hints_link_segments( AF_GlyphHints hints, 162 AF_Dimension dim ) 163 { 164 AF_AxisHints axis = &hints->axis[dim]; 165 AF_Segment segments = axis->segments; 166 AF_Segment segment_limit = segments + axis->num_segments; 167 AF_Direction major_dir = axis->major_dir; 168 AF_Segment seg1, seg2; 169 FT_Pos len_threshold; 170 FT_Pos dist_threshold; 171 172 173 len_threshold = AF_LATIN_CONSTANT( hints->metrics, 8 ); 174 175 dist_threshold = ( dim == AF_DIMENSION_HORZ ) ? hints->x_scale 176 : hints->y_scale; 177 dist_threshold = FT_DivFix( 64 * 3, dist_threshold ); 178 179 /* now compare each segment to the others */ 180 for ( seg1 = segments; seg1 < segment_limit; seg1++ ) 181 { 182 /* the fake segments are for metrics hinting only */ 183 if ( seg1->first == seg1->last ) 184 continue; 185 186 if ( seg1->dir != major_dir ) 187 continue; 188 189 for ( seg2 = segments; seg2 < segment_limit; seg2++ ) 190 if ( seg2 != seg1 && seg1->dir + seg2->dir == 0 ) 191 { 192 FT_Pos dist = seg2->pos - seg1->pos; 193 194 195 if ( dist < 0 ) 196 continue; 197 198 { 199 FT_Pos min = seg1->min_coord; 200 FT_Pos max = seg1->max_coord; 201 FT_Pos len; 202 203 204 if ( min < seg2->min_coord ) 205 min = seg2->min_coord; 206 207 if ( max > seg2->max_coord ) 208 max = seg2->max_coord; 209 210 len = max - min; 211 if ( len >= len_threshold ) 212 { 213 if ( dist * 8 < seg1->score * 9 && 214 ( dist * 8 < seg1->score * 7 || seg1->len < len ) ) 215 { 216 seg1->score = dist; 217 seg1->len = len; 218 seg1->link = seg2; 219 } 220 221 if ( dist * 8 < seg2->score * 9 && 222 ( dist * 8 < seg2->score * 7 || seg2->len < len ) ) 223 { 224 seg2->score = dist; 225 seg2->len = len; 226 seg2->link = seg1; 227 } 228 } 229 } 230 } 231 } 232 233 /* 234 * now compute the `serif' segments 235 * 236 * In Hanzi, some strokes are wider on one or both of the ends. 237 * We either identify the stems on the ends as serifs or remove 238 * the linkage, depending on the length of the stems. 239 * 240 */ 241 242 { 243 AF_Segment link1, link2; 244 245 246 for ( seg1 = segments; seg1 < segment_limit; seg1++ ) 247 { 248 link1 = seg1->link; 249 if ( !link1 || link1->link != seg1 || link1->pos <= seg1->pos ) 250 continue; 251 252 if ( seg1->score >= dist_threshold ) 253 continue; 254 255 for ( seg2 = segments; seg2 < segment_limit; seg2++ ) 256 { 257 if ( seg2->pos > seg1->pos || seg1 == seg2 ) 258 continue; 259 260 link2 = seg2->link; 261 if ( !link2 || link2->link != seg2 || link2->pos < link1->pos ) 262 continue; 263 264 if ( seg1->pos == seg2->pos && link1->pos == link2->pos ) 265 continue; 266 267 if ( seg2->score <= seg1->score || seg1->score * 4 <= seg2->score ) 268 continue; 269 270 /* seg2 < seg1 < link1 < link2 */ 271 272 if ( seg1->len >= seg2->len * 3 ) 273 { 274 AF_Segment seg; 275 276 277 for ( seg = segments; seg < segment_limit; seg++ ) 278 { 279 AF_Segment link = seg->link; 280 281 282 if ( link == seg2 ) 283 { 284 seg->link = 0; 285 seg->serif = link1; 286 } 287 else if ( link == link2 ) 288 { 289 seg->link = 0; 290 seg->serif = seg1; 291 } 292 } 293 } 294 else 295 { 296 seg1->link = link1->link = 0; 297 298 break; 299 } 300 } 301 } 302 } 303 304 for ( seg1 = segments; seg1 < segment_limit; seg1++ ) 305 { 306 seg2 = seg1->link; 307 308 if ( seg2 ) 309 { 310 seg2->num_linked++; 311 if ( seg2->link != seg1 ) 312 { 313 seg1->link = 0; 314 315 if ( seg2->score < dist_threshold || seg1->score < seg2->score * 4 ) 316 seg1->serif = seg2->link; 317 else 318 seg2->num_linked--; 319 } 320 } 321 } 322 } 323 324 325 static FT_Error 326 af_cjk_hints_compute_edges( AF_GlyphHints hints, 327 AF_Dimension dim ) 328 { 329 AF_AxisHints axis = &hints->axis[dim]; 330 FT_Error error = AF_Err_Ok; 331 FT_Memory memory = hints->memory; 332 AF_LatinAxis laxis = &((AF_LatinMetrics)hints->metrics)->axis[dim]; 333 334 AF_Segment segments = axis->segments; 335 AF_Segment segment_limit = segments + axis->num_segments; 336 AF_Segment seg; 337 338 FT_Fixed scale; 339 FT_Pos edge_distance_threshold; 340 341 342 axis->num_edges = 0; 343 344 scale = ( dim == AF_DIMENSION_HORZ ) ? hints->x_scale 345 : hints->y_scale; 346 347 /*********************************************************************/ 348 /* */ 349 /* We begin by generating a sorted table of edges for the current */ 350 /* direction. To do so, we simply scan each segment and try to find */ 351 /* an edge in our table that corresponds to its position. */ 352 /* */ 353 /* If no edge is found, we create and insert a new edge in the */ 354 /* sorted table. Otherwise, we simply add the segment to the edge's */ 355 /* list which is then processed in the second step to compute the */ 356 /* edge's properties. */ 357 /* */ 358 /* Note that the edges table is sorted along the segment/edge */ 359 /* position. */ 360 /* */ 361 /*********************************************************************/ 362 363 edge_distance_threshold = FT_MulFix( laxis->edge_distance_threshold, 364 scale ); 365 if ( edge_distance_threshold > 64 / 4 ) 366 edge_distance_threshold = FT_DivFix( 64 / 4, scale ); 367 else 368 edge_distance_threshold = laxis->edge_distance_threshold; 369 370 for ( seg = segments; seg < segment_limit; seg++ ) 371 { 372 AF_Edge found = 0; 373 FT_Pos best = 0xFFFFU; 374 FT_Int ee; 375 376 377 /* look for an edge corresponding to the segment */ 378 for ( ee = 0; ee < axis->num_edges; ee++ ) 379 { 380 AF_Edge edge = axis->edges + ee; 381 FT_Pos dist; 382 383 384 if ( edge->dir != seg->dir ) 385 continue; 386 387 dist = seg->pos - edge->fpos; 388 if ( dist < 0 ) 389 dist = -dist; 390 391 if ( dist < edge_distance_threshold && dist < best ) 392 { 393 AF_Segment link = seg->link; 394 395 396 /* check whether all linked segments of the candidate edge */ 397 /* can make a single edge. */ 398 if ( link ) 399 { 400 AF_Segment seg1 = edge->first; 401 AF_Segment link1; 402 FT_Pos dist2 = 0; 403 404 405 do 406 { 407 link1 = seg1->link; 408 if ( link1 ) 409 { 410 dist2 = AF_SEGMENT_DIST( link, link1 ); 411 if ( dist2 >= edge_distance_threshold ) 412 break; 413 } 414 415 } while ( ( seg1 = seg1->edge_next ) != edge->first ); 416 417 if ( dist2 >= edge_distance_threshold ) 418 continue; 419 } 420 421 best = dist; 422 found = edge; 423 } 424 } 425 426 if ( !found ) 427 { 428 AF_Edge edge; 429 430 431 /* insert a new edge in the list and */ 432 /* sort according to the position */ 433 error = af_axis_hints_new_edge( axis, seg->pos, 434 (AF_Direction)seg->dir, 435 memory, &edge ); 436 if ( error ) 437 goto Exit; 438 439 /* add the segment to the new edge's list */ 440 FT_ZERO( edge ); 441 442 edge->first = seg; 443 edge->last = seg; 444 edge->fpos = seg->pos; 445 edge->opos = edge->pos = FT_MulFix( seg->pos, scale ); 446 seg->edge_next = seg; 447 edge->dir = seg->dir; 448 } 449 else 450 { 451 /* if an edge was found, simply add the segment to the edge's */ 452 /* list */ 453 seg->edge_next = found->first; 454 found->last->edge_next = seg; 455 found->last = seg; 456 } 457 } 458 459 /*********************************************************************/ 460 /* */ 461 /* Good, we now compute each edge's properties according to segments */ 462 /* found on its position. Basically, these are as follows. */ 463 /* */ 464 /* - edge's main direction */ 465 /* - stem edge, serif edge or both (which defaults to stem then) */ 466 /* - rounded edge, straight or both (which defaults to straight) */ 467 /* - link for edge */ 468 /* */ 469 /*********************************************************************/ 470 471 /* first of all, set the `edge' field in each segment -- this is */ 472 /* required in order to compute edge links */ 473 /* */ 474 /* Note that removing this loop and setting the `edge' field of each */ 475 /* segment directly in the code above slows down execution speed for */ 476 /* some reasons on platforms like the Sun. */ 477 478 { 479 AF_Edge edges = axis->edges; 480 AF_Edge edge_limit = edges + axis->num_edges; 481 AF_Edge edge; 482 483 484 for ( edge = edges; edge < edge_limit; edge++ ) 485 { 486 seg = edge->first; 487 if ( seg ) 488 do 489 { 490 seg->edge = edge; 491 seg = seg->edge_next; 492 493 } while ( seg != edge->first ); 494 } 495 496 /* now compute each edge properties */ 497 for ( edge = edges; edge < edge_limit; edge++ ) 498 { 499 FT_Int is_round = 0; /* does it contain round segments? */ 500 FT_Int is_straight = 0; /* does it contain straight segments? */ 501 502 503 seg = edge->first; 504 505 do 506 { 507 FT_Bool is_serif; 508 509 510 /* check for roundness of segment */ 511 if ( seg->flags & AF_EDGE_ROUND ) 512 is_round++; 513 else 514 is_straight++; 515 516 /* check for links -- if seg->serif is set, then seg->link must */ 517 /* be ignored */ 518 is_serif = (FT_Bool)( seg->serif && seg->serif->edge != edge ); 519 520 if ( seg->link || is_serif ) 521 { 522 AF_Edge edge2; 523 AF_Segment seg2; 524 525 526 edge2 = edge->link; 527 seg2 = seg->link; 528 529 if ( is_serif ) 530 { 531 seg2 = seg->serif; 532 edge2 = edge->serif; 533 } 534 535 if ( edge2 ) 536 { 537 FT_Pos edge_delta; 538 FT_Pos seg_delta; 539 540 541 edge_delta = edge->fpos - edge2->fpos; 542 if ( edge_delta < 0 ) 543 edge_delta = -edge_delta; 544 545 seg_delta = AF_SEGMENT_DIST( seg, seg2 ); 546 547 if ( seg_delta < edge_delta ) 548 edge2 = seg2->edge; 549 } 550 else 551 edge2 = seg2->edge; 552 553 if ( is_serif ) 554 { 555 edge->serif = edge2; 556 edge2->flags |= AF_EDGE_SERIF; 557 } 558 else 559 edge->link = edge2; 560 } 561 562 seg = seg->edge_next; 563 564 } while ( seg != edge->first ); 565 566 /* set the round/straight flags */ 567 edge->flags = AF_EDGE_NORMAL; 568 569 if ( is_round > 0 && is_round >= is_straight ) 570 edge->flags |= AF_EDGE_ROUND; 571 572 /* get rid of serifs if link is set */ 573 /* XXX: This gets rid of many unpleasant artefacts! */ 574 /* Example: the `c' in cour.pfa at size 13 */ 575 576 if ( edge->serif && edge->link ) 577 edge->serif = 0; 578 } 579 } 580 581 Exit: 582 return error; 583 } 584 585 586 static FT_Error 587 af_cjk_hints_detect_features( AF_GlyphHints hints, 588 AF_Dimension dim ) 589 { 590 FT_Error error; 591 592 593 error = af_cjk_hints_compute_segments( hints, dim ); 594 if ( !error ) 595 { 596 af_cjk_hints_link_segments( hints, dim ); 597 598 error = af_cjk_hints_compute_edges( hints, dim ); 599 } 600 return error; 601 } 602 603 604 FT_LOCAL_DEF( FT_Error ) 605 af_cjk_hints_init( AF_GlyphHints hints, 606 AF_LatinMetrics metrics ) 607 { 608 FT_Render_Mode mode; 609 FT_UInt32 scaler_flags, other_flags; 610 611 612 af_glyph_hints_rescale( hints, (AF_ScriptMetrics)metrics ); 613 614 /* 615 * correct x_scale and y_scale when needed, since they may have 616 * been modified af_cjk_scale_dim above 617 */ 618 hints->x_scale = metrics->axis[AF_DIMENSION_HORZ].scale; 619 hints->x_delta = metrics->axis[AF_DIMENSION_HORZ].delta; 620 hints->y_scale = metrics->axis[AF_DIMENSION_VERT].scale; 621 hints->y_delta = metrics->axis[AF_DIMENSION_VERT].delta; 622 623 /* compute flags depending on render mode, etc. */ 624 mode = metrics->root.scaler.render_mode; 625 626 #ifdef AF_USE_WARPER 627 if ( mode == FT_RENDER_MODE_LCD || mode == FT_RENDER_MODE_LCD_V ) 628 metrics->root.scaler.render_mode = mode = FT_RENDER_MODE_NORMAL; 629 #endif 630 631 scaler_flags = hints->scaler_flags; 632 other_flags = 0; 633 634 /* 635 * We snap the width of vertical stems for the monochrome and 636 * horizontal LCD rendering targets only. 637 */ 638 if ( mode == FT_RENDER_MODE_MONO || mode == FT_RENDER_MODE_LCD ) 639 other_flags |= AF_LATIN_HINTS_HORZ_SNAP; 640 641 /* 642 * We snap the width of horizontal stems for the monochrome and 643 * vertical LCD rendering targets only. 644 */ 645 if ( mode == FT_RENDER_MODE_MONO || mode == FT_RENDER_MODE_LCD_V ) 646 other_flags |= AF_LATIN_HINTS_VERT_SNAP; 647 648 /* 649 * We adjust stems to full pixels only if we don't use the `light' mode. 650 */ 651 if ( mode != FT_RENDER_MODE_LIGHT ) 652 other_flags |= AF_LATIN_HINTS_STEM_ADJUST; 653 654 if ( mode == FT_RENDER_MODE_MONO ) 655 other_flags |= AF_LATIN_HINTS_MONO; 656 657 scaler_flags |= AF_SCALER_FLAG_NO_ADVANCE; 658 659 hints->scaler_flags = scaler_flags; 660 hints->other_flags = other_flags; 661 662 return 0; 663 } 664 665 666 /*************************************************************************/ 667 /*************************************************************************/ 668 /***** *****/ 669 /***** C J K G L Y P H G R I D - F I T T I N G *****/ 670 /***** *****/ 671 /*************************************************************************/ 672 /*************************************************************************/ 673 674 /* snap a given width in scaled coordinates to one of the */ 675 /* current standard widths */ 676 677 static FT_Pos 678 af_cjk_snap_width( AF_Width widths, 679 FT_Int count, 680 FT_Pos width ) 681 { 682 int n; 683 FT_Pos best = 64 + 32 + 2; 684 FT_Pos reference = width; 685 FT_Pos scaled; 686 687 688 for ( n = 0; n < count; n++ ) 689 { 690 FT_Pos w; 691 FT_Pos dist; 692 693 694 w = widths[n].cur; 695 dist = width - w; 696 if ( dist < 0 ) 697 dist = -dist; 698 if ( dist < best ) 699 { 700 best = dist; 701 reference = w; 702 } 703 } 704 705 scaled = FT_PIX_ROUND( reference ); 706 707 if ( width >= reference ) 708 { 709 if ( width < scaled + 48 ) 710 width = reference; 711 } 712 else 713 { 714 if ( width > scaled - 48 ) 715 width = reference; 716 } 717 718 return width; 719 } 720 721 722 /* compute the snapped width of a given stem */ 723 724 static FT_Pos 725 af_cjk_compute_stem_width( AF_GlyphHints hints, 726 AF_Dimension dim, 727 FT_Pos width, 728 AF_Edge_Flags base_flags, 729 AF_Edge_Flags stem_flags ) 730 { 731 AF_LatinMetrics metrics = (AF_LatinMetrics) hints->metrics; 732 AF_LatinAxis axis = & metrics->axis[dim]; 733 FT_Pos dist = width; 734 FT_Int sign = 0; 735 FT_Int vertical = ( dim == AF_DIMENSION_VERT ); 736 737 FT_UNUSED( base_flags ); 738 FT_UNUSED( stem_flags ); 739 740 741 if ( !AF_LATIN_HINTS_DO_STEM_ADJUST( hints ) ) 742 return width; 743 744 if ( dist < 0 ) 745 { 746 dist = -width; 747 sign = 1; 748 } 749 750 if ( ( vertical && !AF_LATIN_HINTS_DO_VERT_SNAP( hints ) ) || 751 ( !vertical && !AF_LATIN_HINTS_DO_HORZ_SNAP( hints ) ) ) 752 { 753 /* smooth hinting process: very lightly quantize the stem width */ 754 755 if ( axis->width_count > 0 ) 756 { 757 if ( FT_ABS( dist - axis->widths[0].cur ) < 40 ) 758 { 759 dist = axis->widths[0].cur; 760 if ( dist < 48 ) 761 dist = 48; 762 763 goto Done_Width; 764 } 765 } 766 767 if ( dist < 54 ) 768 dist += ( 54 - dist ) / 2 ; 769 else if ( dist < 3 * 64 ) 770 { 771 FT_Pos delta; 772 773 774 delta = dist & 63; 775 dist &= -64; 776 777 if ( delta < 10 ) 778 dist += delta; 779 else if ( delta < 22 ) 780 dist += 10; 781 else if ( delta < 42 ) 782 dist += delta; 783 else if ( delta < 54 ) 784 dist += 54; 785 else 786 dist += delta; 787 } 788 } 789 else 790 { 791 /* strong hinting process: snap the stem width to integer pixels */ 792 793 dist = af_cjk_snap_width( axis->widths, axis->width_count, dist ); 794 795 if ( vertical ) 796 { 797 /* in the case of vertical hinting, always round */ 798 /* the stem heights to integer pixels */ 799 800 if ( dist >= 64 ) 801 dist = ( dist + 16 ) & ~63; 802 else 803 dist = 64; 804 } 805 else 806 { 807 if ( AF_LATIN_HINTS_DO_MONO( hints ) ) 808 { 809 /* monochrome horizontal hinting: snap widths to integer pixels */ 810 /* with a different threshold */ 811 812 if ( dist < 64 ) 813 dist = 64; 814 else 815 dist = ( dist + 32 ) & ~63; 816 } 817 else 818 { 819 /* for horizontal anti-aliased hinting, we adopt a more subtle */ 820 /* approach: we strengthen small stems, round stems whose size */ 821 /* is between 1 and 2 pixels to an integer, otherwise nothing */ 822 823 if ( dist < 48 ) 824 dist = ( dist + 64 ) >> 1; 825 826 else if ( dist < 128 ) 827 dist = ( dist + 22 ) & ~63; 828 else 829 /* round otherwise to prevent color fringes in LCD mode */ 830 dist = ( dist + 32 ) & ~63; 831 } 832 } 833 } 834 835 Done_Width: 836 if ( sign ) 837 dist = -dist; 838 839 return dist; 840 } 841 842 843 /* align one stem edge relative to the previous stem edge */ 844 845 static void 846 af_cjk_align_linked_edge( AF_GlyphHints hints, 847 AF_Dimension dim, 848 AF_Edge base_edge, 849 AF_Edge stem_edge ) 850 { 851 FT_Pos dist = stem_edge->opos - base_edge->opos; 852 853 FT_Pos fitted_width = af_cjk_compute_stem_width( 854 hints, dim, dist, 855 (AF_Edge_Flags)base_edge->flags, 856 (AF_Edge_Flags)stem_edge->flags ); 857 858 859 stem_edge->pos = base_edge->pos + fitted_width; 860 } 861 862 863 static void 864 af_cjk_align_serif_edge( AF_GlyphHints hints, 865 AF_Edge base, 866 AF_Edge serif ) 867 { 868 FT_UNUSED( hints ); 869 870 serif->pos = base->pos + ( serif->opos - base->opos ); 871 } 872 873 874 /*************************************************************************/ 875 /*************************************************************************/ 876 /*************************************************************************/ 877 /**** ****/ 878 /**** E D G E H I N T I N G ****/ 879 /**** ****/ 880 /*************************************************************************/ 881 /*************************************************************************/ 882 /*************************************************************************/ 883 884 885 #define AF_LIGHT_MODE_MAX_HORZ_GAP 9 886 #define AF_LIGHT_MODE_MAX_VERT_GAP 15 887 #define AF_LIGHT_MODE_MAX_DELTA_ABS 14 888 889 890 static FT_Pos 891 af_hint_normal_stem( AF_GlyphHints hints, 892 AF_Edge edge, 893 AF_Edge edge2, 894 FT_Pos anchor, 895 AF_Dimension dim ) 896 { 897 FT_Pos org_len, cur_len, org_center; 898 FT_Pos cur_pos1, cur_pos2; 899 FT_Pos d_off1, u_off1, d_off2, u_off2, delta; 900 FT_Pos offset; 901 FT_Pos threshold = 64; 902 903 904 if ( !AF_LATIN_HINTS_DO_STEM_ADJUST( hints ) ) 905 { 906 if ( ( edge->flags & AF_EDGE_ROUND ) && 907 ( edge2->flags & AF_EDGE_ROUND ) ) 908 { 909 if ( dim == AF_DIMENSION_VERT ) 910 threshold = 64 - AF_LIGHT_MODE_MAX_HORZ_GAP; 911 else 912 threshold = 64 - AF_LIGHT_MODE_MAX_VERT_GAP; 913 } 914 else 915 { 916 if ( dim == AF_DIMENSION_VERT ) 917 threshold = 64 - AF_LIGHT_MODE_MAX_HORZ_GAP / 3; 918 else 919 threshold = 64 - AF_LIGHT_MODE_MAX_VERT_GAP / 3; 920 } 921 } 922 923 org_len = edge2->opos - edge->opos; 924 cur_len = af_cjk_compute_stem_width( hints, dim, org_len, 925 (AF_Edge_Flags)edge->flags, 926 (AF_Edge_Flags)edge2->flags ); 927 928 org_center = ( edge->opos + edge2->opos ) / 2 + anchor; 929 cur_pos1 = org_center - cur_len / 2; 930 cur_pos2 = cur_pos1 + cur_len; 931 d_off1 = cur_pos1 - FT_PIX_FLOOR( cur_pos1 ); 932 d_off2 = cur_pos2 - FT_PIX_FLOOR( cur_pos2 ); 933 u_off1 = 64 - d_off1; 934 u_off2 = 64 - d_off2; 935 delta = 0; 936 937 938 if ( d_off1 == 0 || d_off2 == 0 ) 939 goto Exit; 940 941 if ( cur_len <= threshold ) 942 { 943 if ( d_off2 < cur_len ) 944 { 945 if ( u_off1 <= d_off2 ) 946 delta = u_off1; 947 else 948 delta = -d_off2; 949 } 950 951 goto Exit; 952 } 953 954 if ( threshold < 64 ) 955 { 956 if ( d_off1 >= threshold || u_off1 >= threshold || 957 d_off2 >= threshold || u_off2 >= threshold ) 958 goto Exit; 959 } 960 961 offset = cur_len % 64; 962 963 if ( offset < 32 ) 964 { 965 if ( u_off1 <= offset || d_off2 <= offset ) 966 goto Exit; 967 } 968 else 969 offset = 64 - threshold; 970 971 d_off1 = threshold - u_off1; 972 u_off1 = u_off1 - offset; 973 u_off2 = threshold - d_off2; 974 d_off2 = d_off2 - offset; 975 976 if ( d_off1 <= u_off1 ) 977 u_off1 = -d_off1; 978 979 if ( d_off2 <= u_off2 ) 980 u_off2 = -d_off2; 981 982 if ( FT_ABS( u_off1 ) <= FT_ABS( u_off2 ) ) 983 delta = u_off1; 984 else 985 delta = u_off2; 986 987 Exit: 988 989 #if 1 990 if ( !AF_LATIN_HINTS_DO_STEM_ADJUST( hints ) ) 991 { 992 if ( delta > AF_LIGHT_MODE_MAX_DELTA_ABS ) 993 delta = AF_LIGHT_MODE_MAX_DELTA_ABS; 994 else if ( delta < -AF_LIGHT_MODE_MAX_DELTA_ABS ) 995 delta = -AF_LIGHT_MODE_MAX_DELTA_ABS; 996 } 997 #endif 998 999 cur_pos1 += delta; 1000 1001 if ( edge->opos < edge2->opos ) 1002 { 1003 edge->pos = cur_pos1; 1004 edge2->pos = cur_pos1 + cur_len; 1005 } 1006 else 1007 { 1008 edge->pos = cur_pos1 + cur_len; 1009 edge2->pos = cur_pos1; 1010 } 1011 1012 return delta; 1013 } 1014 1015 1016 static void 1017 af_cjk_hint_edges( AF_GlyphHints hints, 1018 AF_Dimension dim ) 1019 { 1020 AF_AxisHints axis = &hints->axis[dim]; 1021 AF_Edge edges = axis->edges; 1022 AF_Edge edge_limit = edges + axis->num_edges; 1023 FT_PtrDist n_edges; 1024 AF_Edge edge; 1025 AF_Edge anchor = 0; 1026 FT_Pos delta = 0; 1027 FT_Int skipped = 0; 1028 1029 1030 /* now we align all stem edges. */ 1031 for ( edge = edges; edge < edge_limit; edge++ ) 1032 { 1033 AF_Edge edge2; 1034 1035 1036 if ( edge->flags & AF_EDGE_DONE ) 1037 continue; 1038 1039 /* skip all non-stem edges */ 1040 edge2 = edge->link; 1041 if ( !edge2 ) 1042 { 1043 skipped++; 1044 continue; 1045 } 1046 1047 /* now align the stem */ 1048 1049 if ( edge2 < edge ) 1050 { 1051 af_cjk_align_linked_edge( hints, dim, edge2, edge ); 1052 edge->flags |= AF_EDGE_DONE; 1053 continue; 1054 } 1055 1056 if ( dim != AF_DIMENSION_VERT && !anchor ) 1057 { 1058 1059 #if 0 1060 if ( fixedpitch ) 1061 { 1062 AF_Edge left = edge; 1063 AF_Edge right = edge_limit - 1; 1064 AF_EdgeRec left1, left2, right1, right2; 1065 FT_Pos target, center1, center2; 1066 FT_Pos delta1, delta2, d1, d2; 1067 1068 1069 while ( right > left && !right->link ) 1070 right--; 1071 1072 left1 = *left; 1073 left2 = *left->link; 1074 right1 = *right->link; 1075 right2 = *right; 1076 1077 delta = ( ( ( hinter->pp2.x + 32 ) & -64 ) - hinter->pp2.x ) / 2; 1078 target = left->opos + ( right->opos - left->opos ) / 2 + delta - 16; 1079 1080 delta1 = delta; 1081 delta1 += af_hint_normal_stem( hints, left, left->link, 1082 delta1, 0 ); 1083 1084 if ( left->link != right ) 1085 af_hint_normal_stem( hints, right->link, right, delta1, 0 ); 1086 1087 center1 = left->pos + ( right->pos - left->pos ) / 2; 1088 1089 if ( center1 >= target ) 1090 delta2 = delta - 32; 1091 else 1092 delta2 = delta + 32; 1093 1094 delta2 += af_hint_normal_stem( hints, &left1, &left2, delta2, 0 ); 1095 1096 if ( delta1 != delta2 ) 1097 { 1098 if ( left->link != right ) 1099 af_hint_normal_stem( hints, &right1, &right2, delta2, 0 ); 1100 1101 center2 = left1.pos + ( right2.pos - left1.pos ) / 2; 1102 1103 d1 = center1 - target; 1104 d2 = center2 - target; 1105 1106 if ( FT_ABS( d2 ) < FT_ABS( d1 ) ) 1107 { 1108 left->pos = left1.pos; 1109 left->link->pos = left2.pos; 1110 1111 if ( left->link != right ) 1112 { 1113 right->link->pos = right1.pos; 1114 right->pos = right2.pos; 1115 } 1116 1117 delta1 = delta2; 1118 } 1119 } 1120 1121 delta = delta1; 1122 right->link->flags |= AF_EDGE_DONE; 1123 right->flags |= AF_EDGE_DONE; 1124 } 1125 else 1126 1127 #endif /* 0 */ 1128 1129 delta = af_hint_normal_stem( hints, edge, edge2, 0, 1130 AF_DIMENSION_HORZ ); 1131 } 1132 else 1133 af_hint_normal_stem( hints, edge, edge2, delta, dim ); 1134 1135 #if 0 1136 printf( "stem (%d,%d) adjusted (%.1f,%.1f)\n", 1137 edge - edges, edge2 - edges, 1138 ( edge->pos - edge->opos ) / 64.0, 1139 ( edge2->pos - edge2->opos ) / 64.0 ); 1140 #endif 1141 1142 anchor = edge; 1143 edge->flags |= AF_EDGE_DONE; 1144 edge2->flags |= AF_EDGE_DONE; 1145 } 1146 1147 /* make sure that lowercase m's maintain their symmetry */ 1148 1149 /* In general, lowercase m's have six vertical edges if they are sans */ 1150 /* serif, or twelve if they are with serifs. This implementation is */ 1151 /* based on that assumption, and seems to work very well with most */ 1152 /* faces. However, if for a certain face this assumption is not */ 1153 /* true, the m is just rendered like before. In addition, any stem */ 1154 /* correction will only be applied to symmetrical glyphs (even if the */ 1155 /* glyph is not an m), so the potential for unwanted distortion is */ 1156 /* relatively low. */ 1157 1158 /* We don't handle horizontal edges since we can't easily assure that */ 1159 /* the third (lowest) stem aligns with the base line; it might end up */ 1160 /* one pixel higher or lower. */ 1161 1162 n_edges = edge_limit - edges; 1163 if ( dim == AF_DIMENSION_HORZ && ( n_edges == 6 || n_edges == 12 ) ) 1164 { 1165 AF_Edge edge1, edge2, edge3; 1166 FT_Pos dist1, dist2, span; 1167 1168 1169 if ( n_edges == 6 ) 1170 { 1171 edge1 = edges; 1172 edge2 = edges + 2; 1173 edge3 = edges + 4; 1174 } 1175 else 1176 { 1177 edge1 = edges + 1; 1178 edge2 = edges + 5; 1179 edge3 = edges + 9; 1180 } 1181 1182 dist1 = edge2->opos - edge1->opos; 1183 dist2 = edge3->opos - edge2->opos; 1184 1185 span = dist1 - dist2; 1186 if ( span < 0 ) 1187 span = -span; 1188 1189 if ( edge1->link == edge1 + 1 && 1190 edge2->link == edge2 + 1 && 1191 edge3->link == edge3 + 1 && span < 8 ) 1192 { 1193 delta = edge3->pos - ( 2 * edge2->pos - edge1->pos ); 1194 edge3->pos -= delta; 1195 if ( edge3->link ) 1196 edge3->link->pos -= delta; 1197 1198 /* move the serifs along with the stem */ 1199 if ( n_edges == 12 ) 1200 { 1201 ( edges + 8 )->pos -= delta; 1202 ( edges + 11 )->pos -= delta; 1203 } 1204 1205 edge3->flags |= AF_EDGE_DONE; 1206 if ( edge3->link ) 1207 edge3->link->flags |= AF_EDGE_DONE; 1208 } 1209 } 1210 1211 if ( !skipped ) 1212 return; 1213 1214 /* 1215 * now hint the remaining edges (serifs and single) in order 1216 * to complete our processing 1217 */ 1218 for ( edge = edges; edge < edge_limit; edge++ ) 1219 { 1220 if ( edge->flags & AF_EDGE_DONE ) 1221 continue; 1222 1223 if ( edge->serif ) 1224 { 1225 af_cjk_align_serif_edge( hints, edge->serif, edge ); 1226 edge->flags |= AF_EDGE_DONE; 1227 skipped--; 1228 } 1229 } 1230 1231 if ( !skipped ) 1232 return; 1233 1234 for ( edge = edges; edge < edge_limit; edge++ ) 1235 { 1236 AF_Edge before, after; 1237 1238 1239 if ( edge->flags & AF_EDGE_DONE ) 1240 continue; 1241 1242 before = after = edge; 1243 1244 while ( --before >= edges ) 1245 if ( before->flags & AF_EDGE_DONE ) 1246 break; 1247 1248 while ( ++after < edge_limit ) 1249 if ( after->flags & AF_EDGE_DONE ) 1250 break; 1251 1252 if ( before >= edges || after < edge_limit ) 1253 { 1254 if ( before < edges ) 1255 af_cjk_align_serif_edge( hints, after, edge ); 1256 else if ( after >= edge_limit ) 1257 af_cjk_align_serif_edge( hints, before, edge ); 1258 else 1259 { 1260 if ( after->fpos == before->fpos ) 1261 edge->pos = before->pos; 1262 else 1263 edge->pos = before->pos + 1264 FT_MulDiv( edge->fpos - before->fpos, 1265 after->pos - before->pos, 1266 after->fpos - before->fpos ); 1267 } 1268 } 1269 } 1270 } 1271 1272 1273 static void 1274 af_cjk_align_edge_points( AF_GlyphHints hints, 1275 AF_Dimension dim ) 1276 { 1277 AF_AxisHints axis = & hints->axis[dim]; 1278 AF_Edge edges = axis->edges; 1279 AF_Edge edge_limit = edges + axis->num_edges; 1280 AF_Edge edge; 1281 FT_Bool snapping; 1282 1283 1284 snapping = FT_BOOL( ( dim == AF_DIMENSION_HORZ && 1285 AF_LATIN_HINTS_DO_HORZ_SNAP( hints ) ) || 1286 ( dim == AF_DIMENSION_VERT && 1287 AF_LATIN_HINTS_DO_VERT_SNAP( hints ) ) ); 1288 1289 for ( edge = edges; edge < edge_limit; edge++ ) 1290 { 1291 /* move the points of each segment */ 1292 /* in each edge to the edge's position */ 1293 AF_Segment seg = edge->first; 1294 1295 1296 if ( snapping ) 1297 { 1298 do 1299 { 1300 AF_Point point = seg->first; 1301 1302 1303 for (;;) 1304 { 1305 if ( dim == AF_DIMENSION_HORZ ) 1306 { 1307 point->x = edge->pos; 1308 point->flags |= AF_FLAG_TOUCH_X; 1309 } 1310 else 1311 { 1312 point->y = edge->pos; 1313 point->flags |= AF_FLAG_TOUCH_Y; 1314 } 1315 1316 if ( point == seg->last ) 1317 break; 1318 1319 point = point->next; 1320 } 1321 1322 seg = seg->edge_next; 1323 1324 } while ( seg != edge->first ); 1325 } 1326 else 1327 { 1328 FT_Pos delta = edge->pos - edge->opos; 1329 1330 1331 do 1332 { 1333 AF_Point point = seg->first; 1334 1335 1336 for (;;) 1337 { 1338 if ( dim == AF_DIMENSION_HORZ ) 1339 { 1340 point->x += delta; 1341 point->flags |= AF_FLAG_TOUCH_X; 1342 } 1343 else 1344 { 1345 point->y += delta; 1346 point->flags |= AF_FLAG_TOUCH_Y; 1347 } 1348 1349 if ( point == seg->last ) 1350 break; 1351 1352 point = point->next; 1353 } 1354 1355 seg = seg->edge_next; 1356 1357 } while ( seg != edge->first ); 1358 } 1359 } 1360 } 1361 1362 1363 FT_LOCAL_DEF( FT_Error ) 1364 af_cjk_hints_apply( AF_GlyphHints hints, 1365 FT_Outline* outline, 1366 AF_LatinMetrics metrics ) 1367 { 1368 FT_Error error; 1369 int dim; 1370 1371 FT_UNUSED( metrics ); 1372 1373 1374 error = af_glyph_hints_reload( hints, outline ); 1375 if ( error ) 1376 goto Exit; 1377 1378 /* analyze glyph outline */ 1379 if ( AF_HINTS_DO_HORIZONTAL( hints ) ) 1380 { 1381 error = af_cjk_hints_detect_features( hints, AF_DIMENSION_HORZ ); 1382 if ( error ) 1383 goto Exit; 1384 } 1385 1386 if ( AF_HINTS_DO_VERTICAL( hints ) ) 1387 { 1388 error = af_cjk_hints_detect_features( hints, AF_DIMENSION_VERT ); 1389 if ( error ) 1390 goto Exit; 1391 } 1392 1393 /* grid-fit the outline */ 1394 for ( dim = 0; dim < AF_DIMENSION_MAX; dim++ ) 1395 { 1396 if ( ( dim == AF_DIMENSION_HORZ && AF_HINTS_DO_HORIZONTAL( hints ) ) || 1397 ( dim == AF_DIMENSION_VERT && AF_HINTS_DO_VERTICAL( hints ) ) ) 1398 { 1399 1400 #ifdef AF_USE_WARPER 1401 if ( dim == AF_DIMENSION_HORZ && 1402 metrics->root.scaler.render_mode == FT_RENDER_MODE_NORMAL ) 1403 { 1404 AF_WarperRec warper; 1405 FT_Fixed scale; 1406 FT_Pos delta; 1407 1408 1409 af_warper_compute( &warper, hints, dim, &scale, &delta ); 1410 af_glyph_hints_scale_dim( hints, dim, scale, delta ); 1411 continue; 1412 } 1413 #endif /* AF_USE_WARPER */ 1414 1415 af_cjk_hint_edges( hints, (AF_Dimension)dim ); 1416 af_cjk_align_edge_points( hints, (AF_Dimension)dim ); 1417 af_glyph_hints_align_strong_points( hints, (AF_Dimension)dim ); 1418 af_glyph_hints_align_weak_points( hints, (AF_Dimension)dim ); 1419 } 1420 } 1421 1422 #if 0 1423 af_glyph_hints_dump_points( hints ); 1424 af_glyph_hints_dump_segments( hints ); 1425 af_glyph_hints_dump_edges( hints ); 1426 #endif 1427 1428 af_glyph_hints_save( hints, outline ); 1429 1430 Exit: 1431 return error; 1432 } 1433 1434 1435 /*************************************************************************/ 1436 /*************************************************************************/ 1437 /***** *****/ 1438 /***** C J K S C R I P T C L A S S *****/ 1439 /***** *****/ 1440 /*************************************************************************/ 1441 /*************************************************************************/ 1442 1443 1444 static const AF_Script_UniRangeRec af_cjk_uniranges[] = 1445 { 1446 #if 0 1447 AF_UNIRANGE_REC( 0x0100UL, 0xFFFFUL ), /* why this? */ 1448 #endif 1449 AF_UNIRANGE_REC( 0x2E80UL, 0x2EFFUL ), /* CJK Radicals Supplement */ 1450 AF_UNIRANGE_REC( 0x2F00UL, 0x2FDFUL ), /* Kangxi Radicals */ 1451 AF_UNIRANGE_REC( 0x3000UL, 0x303FUL ), /* CJK Symbols and Punctuation */ 1452 AF_UNIRANGE_REC( 0x3040UL, 0x309FUL ), /* Hiragana */ 1453 AF_UNIRANGE_REC( 0x30A0UL, 0x30FFUL ), /* Katakana */ 1454 AF_UNIRANGE_REC( 0x3100UL, 0x312FUL ), /* Bopomofo */ 1455 AF_UNIRANGE_REC( 0x3130UL, 0x318FUL ), /* Hangul Compatibility Jamo */ 1456 AF_UNIRANGE_REC( 0x31A0UL, 0x31BFUL ), /* Bopomofo Extended */ 1457 AF_UNIRANGE_REC( 0x31C0UL, 0x31EFUL ), /* CJK Strokes */ 1458 AF_UNIRANGE_REC( 0x31F0UL, 0x31FFUL ), /* Katakana Phonetic Extensions */ 1459 AF_UNIRANGE_REC( 0x3200UL, 0x32FFUL ), /* Enclosed CJK Letters and Months */ 1460 AF_UNIRANGE_REC( 0x3300UL, 0x33FFUL ), /* CJK Compatibility */ 1461 AF_UNIRANGE_REC( 0x3400UL, 0x4DBFUL ), /* CJK Unified Ideographs Extension A */ 1462 AF_UNIRANGE_REC( 0x4DC0UL, 0x4DFFUL ), /* Yijing Hexagram Symbols */ 1463 AF_UNIRANGE_REC( 0x4E00UL, 0x9FFFUL ), /* CJK Unified Ideographs */ 1464 AF_UNIRANGE_REC( 0xF900UL, 0xFAFFUL ), /* CJK Compatibility Ideographs */ 1465 AF_UNIRANGE_REC( 0xFE30UL, 0xFE4FUL ), /* CJK Compatibility Forms */ 1466 AF_UNIRANGE_REC( 0xFF00UL, 0xFFEFUL ), /* Halfwidth and Fullwidth Forms */ 1467 AF_UNIRANGE_REC( 0x20000UL, 0x2A6DFUL ), /* CJK Unified Ideographs Extension B */ 1468 AF_UNIRANGE_REC( 0x2F800UL, 0x2FA1FUL ), /* CJK Compatibility Ideographs Supplement */ 1469 AF_UNIRANGE_REC( 0UL, 0UL ) 1470 }; 1471 1472 1473 AF_DEFINE_SCRIPT_CLASS(af_cjk_script_class, 1474 AF_SCRIPT_CJK, 1475 af_cjk_uniranges, 1476 1477 sizeof( AF_LatinMetricsRec ), 1478 1479 (AF_Script_InitMetricsFunc) af_cjk_metrics_init, 1480 (AF_Script_ScaleMetricsFunc)af_cjk_metrics_scale, 1481 (AF_Script_DoneMetricsFunc) NULL, 1482 1483 (AF_Script_InitHintsFunc) af_cjk_hints_init, 1484 (AF_Script_ApplyHintsFunc) af_cjk_hints_apply 1485 ) 1486 1487 #else /* !AF_CONFIG_OPTION_CJK */ 1488 1489 static const AF_Script_UniRangeRec af_cjk_uniranges[] = 1490 { 1491 AF_UNIRANGE_REC( 0UL, 0UL ) 1492 }; 1493 1494 1495 AF_DEFINE_SCRIPT_CLASS(af_cjk_script_class, 1496 AF_SCRIPT_CJK, 1497 af_cjk_uniranges, 1498 1499 sizeof( AF_LatinMetricsRec ), 1500 1501 (AF_Script_InitMetricsFunc) NULL, 1502 (AF_Script_ScaleMetricsFunc)NULL, 1503 (AF_Script_DoneMetricsFunc) NULL, 1504 1505 (AF_Script_InitHintsFunc) NULL, 1506 (AF_Script_ApplyHintsFunc) NULL 1507 ) 1508 1509 #endif /* !AF_CONFIG_OPTION_CJK */ 1510 1511 1512 /* END */ 1513
