1 /***************************************************************************/ 2 /* */ 3 /* afcjk.c */ 4 /* */ 5 /* Auto-fitter hinting routines for CJK script (body). */ 6 /* */ 7 /* Copyright 2006, 2007, 2008 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 ) af_cjk_metrics_init(AF_LatinMetrics metrics,FT_Face face)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 62 /* latin's version would suffice */ 63 af_latin_metrics_init_widths( metrics, face, 0x7530 ); 64 65 FT_Set_Charmap( face, oldmap ); 66 67 return AF_Err_Ok; 68 } 69 70 71 static void af_cjk_metrics_scale_dim(AF_LatinMetrics metrics,AF_Scaler scaler,AF_Dimension dim)72 af_cjk_metrics_scale_dim( AF_LatinMetrics metrics, 73 AF_Scaler scaler, 74 AF_Dimension dim ) 75 { 76 AF_LatinAxis axis; 77 78 79 axis = &metrics->axis[dim]; 80 81 if ( dim == AF_DIMENSION_HORZ ) 82 { 83 axis->scale = scaler->x_scale; 84 axis->delta = scaler->x_delta; 85 } 86 else 87 { 88 axis->scale = scaler->y_scale; 89 axis->delta = scaler->y_delta; 90 } 91 } 92 93 94 FT_LOCAL_DEF( void ) af_cjk_metrics_scale(AF_LatinMetrics metrics,AF_Scaler scaler)95 af_cjk_metrics_scale( AF_LatinMetrics metrics, 96 AF_Scaler scaler ) 97 { 98 metrics->root.scaler = *scaler; 99 100 af_cjk_metrics_scale_dim( metrics, scaler, AF_DIMENSION_HORZ ); 101 af_cjk_metrics_scale_dim( metrics, scaler, AF_DIMENSION_VERT ); 102 } 103 104 105 /*************************************************************************/ 106 /*************************************************************************/ 107 /***** *****/ 108 /***** C J K G L Y P H A N A L Y S I S *****/ 109 /***** *****/ 110 /*************************************************************************/ 111 /*************************************************************************/ 112 113 static FT_Error af_cjk_hints_compute_segments(AF_GlyphHints hints,AF_Dimension dim)114 af_cjk_hints_compute_segments( AF_GlyphHints hints, 115 AF_Dimension dim ) 116 { 117 AF_AxisHints axis = &hints->axis[dim]; 118 AF_Segment segments = axis->segments; 119 AF_Segment segment_limit = segments + axis->num_segments; 120 FT_Error error; 121 AF_Segment seg; 122 123 124 error = af_latin_hints_compute_segments( hints, dim ); 125 if ( error ) 126 return error; 127 128 /* a segment is round if it doesn't have successive */ 129 /* on-curve points. */ 130 for ( seg = segments; seg < segment_limit; seg++ ) 131 { 132 AF_Point pt = seg->first; 133 AF_Point last = seg->last; 134 AF_Flags f0 = (AF_Flags)(pt->flags & AF_FLAG_CONTROL); 135 AF_Flags f1; 136 137 138 seg->flags &= ~AF_EDGE_ROUND; 139 140 for ( ; pt != last; f0 = f1 ) 141 { 142 pt = pt->next; 143 f1 = (AF_Flags)(pt->flags & AF_FLAG_CONTROL); 144 145 if ( !f0 && !f1 ) 146 break; 147 148 if ( pt == last ) 149 seg->flags |= AF_EDGE_ROUND; 150 } 151 } 152 153 return AF_Err_Ok; 154 } 155 156 157 static void af_cjk_hints_link_segments(AF_GlyphHints hints,AF_Dimension dim)158 af_cjk_hints_link_segments( AF_GlyphHints hints, 159 AF_Dimension dim ) 160 { 161 AF_AxisHints axis = &hints->axis[dim]; 162 AF_Segment segments = axis->segments; 163 AF_Segment segment_limit = segments + axis->num_segments; 164 AF_Direction major_dir = axis->major_dir; 165 AF_Segment seg1, seg2; 166 FT_Pos len_threshold; 167 FT_Pos dist_threshold; 168 169 170 len_threshold = AF_LATIN_CONSTANT( hints->metrics, 8 ); 171 172 dist_threshold = ( dim == AF_DIMENSION_HORZ ) ? hints->x_scale 173 : hints->y_scale; 174 dist_threshold = FT_DivFix( 64 * 3, dist_threshold ); 175 176 /* now compare each segment to the others */ 177 for ( seg1 = segments; seg1 < segment_limit; seg1++ ) 178 { 179 /* the fake segments are for metrics hinting only */ 180 if ( seg1->first == seg1->last ) 181 continue; 182 183 if ( seg1->dir != major_dir ) 184 continue; 185 186 for ( seg2 = segments; seg2 < segment_limit; seg2++ ) 187 if ( seg2 != seg1 && seg1->dir + seg2->dir == 0 ) 188 { 189 FT_Pos dist = seg2->pos - seg1->pos; 190 191 192 if ( dist < 0 ) 193 continue; 194 195 { 196 FT_Pos min = seg1->min_coord; 197 FT_Pos max = seg1->max_coord; 198 FT_Pos len; 199 200 201 if ( min < seg2->min_coord ) 202 min = seg2->min_coord; 203 204 if ( max > seg2->max_coord ) 205 max = seg2->max_coord; 206 207 len = max - min; 208 if ( len >= len_threshold ) 209 { 210 if ( dist * 8 < seg1->score * 9 && 211 ( dist * 8 < seg1->score * 7 || seg1->len < len ) ) 212 { 213 seg1->score = dist; 214 seg1->len = len; 215 seg1->link = seg2; 216 } 217 218 if ( dist * 8 < seg2->score * 9 && 219 ( dist * 8 < seg2->score * 7 || seg2->len < len ) ) 220 { 221 seg2->score = dist; 222 seg2->len = len; 223 seg2->link = seg1; 224 } 225 } 226 } 227 } 228 } 229 230 /* 231 * now compute the `serif' segments 232 * 233 * In Hanzi, some strokes are wider on one or both of the ends. 234 * We either identify the stems on the ends as serifs or remove 235 * the linkage, depending on the length of the stems. 236 * 237 */ 238 239 { 240 AF_Segment link1, link2; 241 242 243 for ( seg1 = segments; seg1 < segment_limit; seg1++ ) 244 { 245 link1 = seg1->link; 246 if ( !link1 || link1->link != seg1 || link1->pos <= seg1->pos ) 247 continue; 248 249 if ( seg1->score >= dist_threshold ) 250 continue; 251 252 for ( seg2 = segments; seg2 < segment_limit; seg2++ ) 253 { 254 if ( seg2->pos > seg1->pos || seg1 == seg2 ) 255 continue; 256 257 link2 = seg2->link; 258 if ( !link2 || link2->link != seg2 || link2->pos < link1->pos ) 259 continue; 260 261 if ( seg1->pos == seg2->pos && link1->pos == link2->pos ) 262 continue; 263 264 if ( seg2->score <= seg1->score || seg1->score * 4 <= seg2->score ) 265 continue; 266 267 /* seg2 < seg1 < link1 < link2 */ 268 269 if ( seg1->len >= seg2->len * 3 ) 270 { 271 AF_Segment seg; 272 273 274 for ( seg = segments; seg < segment_limit; seg++ ) 275 { 276 AF_Segment link = seg->link; 277 278 279 if ( link == seg2 ) 280 { 281 seg->link = 0; 282 seg->serif = link1; 283 } 284 else if ( link == link2 ) 285 { 286 seg->link = 0; 287 seg->serif = seg1; 288 } 289 } 290 } 291 else 292 { 293 seg1->link = link1->link = 0; 294 295 break; 296 } 297 } 298 } 299 } 300 301 for ( seg1 = segments; seg1 < segment_limit; seg1++ ) 302 { 303 seg2 = seg1->link; 304 305 if ( seg2 ) 306 { 307 seg2->num_linked++; 308 if ( seg2->link != seg1 ) 309 { 310 seg1->link = 0; 311 312 if ( seg2->score < dist_threshold || seg1->score < seg2->score * 4 ) 313 seg1->serif = seg2->link; 314 else 315 seg2->num_linked--; 316 } 317 } 318 } 319 } 320 321 322 static FT_Error af_cjk_hints_compute_edges(AF_GlyphHints hints,AF_Dimension dim)323 af_cjk_hints_compute_edges( AF_GlyphHints hints, 324 AF_Dimension dim ) 325 { 326 AF_AxisHints axis = &hints->axis[dim]; 327 FT_Error error = AF_Err_Ok; 328 FT_Memory memory = hints->memory; 329 AF_LatinAxis laxis = &((AF_LatinMetrics)hints->metrics)->axis[dim]; 330 331 AF_Segment segments = axis->segments; 332 AF_Segment segment_limit = segments + axis->num_segments; 333 AF_Segment seg; 334 335 FT_Fixed scale; 336 FT_Pos edge_distance_threshold; 337 338 339 axis->num_edges = 0; 340 341 scale = ( dim == AF_DIMENSION_HORZ ) ? hints->x_scale 342 : hints->y_scale; 343 344 /*********************************************************************/ 345 /* */ 346 /* We begin by generating a sorted table of edges for the current */ 347 /* direction. To do so, we simply scan each segment and try to find */ 348 /* an edge in our table that corresponds to its position. */ 349 /* */ 350 /* If no edge is found, we create and insert a new edge in the */ 351 /* sorted table. Otherwise, we simply add the segment to the edge's */ 352 /* list which is then processed in the second step to compute the */ 353 /* edge's properties. */ 354 /* */ 355 /* Note that the edges table is sorted along the segment/edge */ 356 /* position. */ 357 /* */ 358 /*********************************************************************/ 359 360 edge_distance_threshold = FT_MulFix( laxis->edge_distance_threshold, 361 scale ); 362 if ( edge_distance_threshold > 64 / 4 ) 363 edge_distance_threshold = FT_DivFix( 64 / 4, scale ); 364 else 365 edge_distance_threshold = laxis->edge_distance_threshold; 366 367 for ( seg = segments; seg < segment_limit; seg++ ) 368 { 369 AF_Edge found = 0; 370 FT_Pos best = 0xFFFFU; 371 FT_Int ee; 372 373 374 /* look for an edge corresponding to the segment */ 375 for ( ee = 0; ee < axis->num_edges; ee++ ) 376 { 377 AF_Edge edge = axis->edges + ee; 378 FT_Pos dist; 379 380 381 if ( edge->dir != seg->dir ) 382 continue; 383 384 dist = seg->pos - edge->fpos; 385 if ( dist < 0 ) 386 dist = -dist; 387 388 if ( dist < edge_distance_threshold && dist < best ) 389 { 390 AF_Segment link = seg->link; 391 392 393 /* check whether all linked segments of the candidate edge */ 394 /* can make a single edge. */ 395 if ( link ) 396 { 397 AF_Segment seg1 = edge->first; 398 AF_Segment link1; 399 FT_Pos dist2 = 0; 400 401 402 do 403 { 404 link1 = seg1->link; 405 if ( link1 ) 406 { 407 dist2 = AF_SEGMENT_DIST( link, link1 ); 408 if ( dist2 >= edge_distance_threshold ) 409 break; 410 } 411 412 } while ( ( seg1 = seg1->edge_next ) != edge->first ); 413 414 if ( dist2 >= edge_distance_threshold ) 415 continue; 416 } 417 418 best = dist; 419 found = edge; 420 } 421 } 422 423 if ( !found ) 424 { 425 AF_Edge edge; 426 427 428 /* insert a new edge in the list and */ 429 /* sort according to the position */ 430 error = af_axis_hints_new_edge( axis, seg->pos, 431 (AF_Direction)seg->dir, 432 memory, &edge ); 433 if ( error ) 434 goto Exit; 435 436 /* add the segment to the new edge's list */ 437 FT_ZERO( edge ); 438 439 edge->first = seg; 440 edge->last = seg; 441 edge->fpos = seg->pos; 442 edge->opos = edge->pos = FT_MulFix( seg->pos, scale ); 443 seg->edge_next = seg; 444 edge->dir = seg->dir; 445 } 446 else 447 { 448 /* if an edge was found, simply add the segment to the edge's */ 449 /* list */ 450 seg->edge_next = found->first; 451 found->last->edge_next = seg; 452 found->last = seg; 453 } 454 } 455 456 /*********************************************************************/ 457 /* */ 458 /* Good, we now compute each edge's properties according to segments */ 459 /* found on its position. Basically, these are as follows. */ 460 /* */ 461 /* - edge's main direction */ 462 /* - stem edge, serif edge or both (which defaults to stem then) */ 463 /* - rounded edge, straight or both (which defaults to straight) */ 464 /* - link for edge */ 465 /* */ 466 /*********************************************************************/ 467 468 /* first of all, set the `edge' field in each segment -- this is */ 469 /* required in order to compute edge links */ 470 /* */ 471 /* Note that removing this loop and setting the `edge' field of each */ 472 /* segment directly in the code above slows down execution speed for */ 473 /* some reasons on platforms like the Sun. */ 474 475 { 476 AF_Edge edges = axis->edges; 477 AF_Edge edge_limit = edges + axis->num_edges; 478 AF_Edge edge; 479 480 481 for ( edge = edges; edge < edge_limit; edge++ ) 482 { 483 seg = edge->first; 484 if ( seg ) 485 do 486 { 487 seg->edge = edge; 488 seg = seg->edge_next; 489 490 } while ( seg != edge->first ); 491 } 492 493 /* now compute each edge properties */ 494 for ( edge = edges; edge < edge_limit; edge++ ) 495 { 496 FT_Int is_round = 0; /* does it contain round segments? */ 497 FT_Int is_straight = 0; /* does it contain straight segments? */ 498 499 500 seg = edge->first; 501 502 do 503 { 504 FT_Bool is_serif; 505 506 507 /* check for roundness of segment */ 508 if ( seg->flags & AF_EDGE_ROUND ) 509 is_round++; 510 else 511 is_straight++; 512 513 /* check for links -- if seg->serif is set, then seg->link must */ 514 /* be ignored */ 515 is_serif = (FT_Bool)( seg->serif && seg->serif->edge != edge ); 516 517 if ( seg->link || is_serif ) 518 { 519 AF_Edge edge2; 520 AF_Segment seg2; 521 522 523 edge2 = edge->link; 524 seg2 = seg->link; 525 526 if ( is_serif ) 527 { 528 seg2 = seg->serif; 529 edge2 = edge->serif; 530 } 531 532 if ( edge2 ) 533 { 534 FT_Pos edge_delta; 535 FT_Pos seg_delta; 536 537 538 edge_delta = edge->fpos - edge2->fpos; 539 if ( edge_delta < 0 ) 540 edge_delta = -edge_delta; 541 542 seg_delta = AF_SEGMENT_DIST( seg, seg2 ); 543 544 if ( seg_delta < edge_delta ) 545 edge2 = seg2->edge; 546 } 547 else 548 edge2 = seg2->edge; 549 550 if ( is_serif ) 551 { 552 edge->serif = edge2; 553 edge2->flags |= AF_EDGE_SERIF; 554 } 555 else 556 edge->link = edge2; 557 } 558 559 seg = seg->edge_next; 560 561 } while ( seg != edge->first ); 562 563 /* set the round/straight flags */ 564 edge->flags = AF_EDGE_NORMAL; 565 566 if ( is_round > 0 && is_round >= is_straight ) 567 edge->flags |= AF_EDGE_ROUND; 568 569 /* get rid of serifs if link is set */ 570 /* XXX: This gets rid of many unpleasant artefacts! */ 571 /* Example: the `c' in cour.pfa at size 13 */ 572 573 if ( edge->serif && edge->link ) 574 edge->serif = 0; 575 } 576 } 577 578 Exit: 579 return error; 580 } 581 582 583 static FT_Error af_cjk_hints_detect_features(AF_GlyphHints hints,AF_Dimension dim)584 af_cjk_hints_detect_features( AF_GlyphHints hints, 585 AF_Dimension dim ) 586 { 587 FT_Error error; 588 589 590 error = af_cjk_hints_compute_segments( hints, dim ); 591 if ( !error ) 592 { 593 af_cjk_hints_link_segments( hints, dim ); 594 595 error = af_cjk_hints_compute_edges( hints, dim ); 596 } 597 return error; 598 } 599 600 601 FT_LOCAL_DEF( FT_Error ) af_cjk_hints_init(AF_GlyphHints hints,AF_LatinMetrics metrics)602 af_cjk_hints_init( AF_GlyphHints hints, 603 AF_LatinMetrics metrics ) 604 { 605 FT_Render_Mode mode; 606 FT_UInt32 scaler_flags, other_flags; 607 608 609 af_glyph_hints_rescale( hints, (AF_ScriptMetrics)metrics ); 610 611 /* 612 * correct x_scale and y_scale when needed, since they may have 613 * been modified af_cjk_scale_dim above 614 */ 615 hints->x_scale = metrics->axis[AF_DIMENSION_HORZ].scale; 616 hints->x_delta = metrics->axis[AF_DIMENSION_HORZ].delta; 617 hints->y_scale = metrics->axis[AF_DIMENSION_VERT].scale; 618 hints->y_delta = metrics->axis[AF_DIMENSION_VERT].delta; 619 620 /* compute flags depending on render mode, etc. */ 621 mode = metrics->root.scaler.render_mode; 622 623 #ifdef AF_USE_WARPER 624 if ( mode == FT_RENDER_MODE_LCD || mode == FT_RENDER_MODE_LCD_V ) 625 metrics->root.scaler.render_mode = mode = FT_RENDER_MODE_NORMAL; 626 #endif 627 628 scaler_flags = hints->scaler_flags; 629 other_flags = 0; 630 631 /* 632 * We snap the width of vertical stems for the monochrome and 633 * horizontal LCD rendering targets only. 634 */ 635 if ( mode == FT_RENDER_MODE_MONO || mode == FT_RENDER_MODE_LCD ) 636 other_flags |= AF_LATIN_HINTS_HORZ_SNAP; 637 638 /* 639 * We snap the width of horizontal stems for the monochrome and 640 * vertical LCD rendering targets only. 641 */ 642 if ( mode == FT_RENDER_MODE_MONO || mode == FT_RENDER_MODE_LCD_V ) 643 other_flags |= AF_LATIN_HINTS_VERT_SNAP; 644 645 /* 646 * We adjust stems to full pixels only if we don't use the `light' mode. 647 */ 648 if ( mode != FT_RENDER_MODE_LIGHT ) 649 other_flags |= AF_LATIN_HINTS_STEM_ADJUST; 650 651 if ( mode == FT_RENDER_MODE_MONO ) 652 other_flags |= AF_LATIN_HINTS_MONO; 653 654 scaler_flags |= AF_SCALER_FLAG_NO_ADVANCE; 655 656 hints->scaler_flags = scaler_flags; 657 hints->other_flags = other_flags; 658 659 return 0; 660 } 661 662 663 /*************************************************************************/ 664 /*************************************************************************/ 665 /***** *****/ 666 /***** C J K G L Y P H G R I D - F I T T I N G *****/ 667 /***** *****/ 668 /*************************************************************************/ 669 /*************************************************************************/ 670 671 /* snap a given width in scaled coordinates to one of the */ 672 /* current standard widths */ 673 674 static FT_Pos af_cjk_snap_width(AF_Width widths,FT_Int count,FT_Pos width)675 af_cjk_snap_width( AF_Width widths, 676 FT_Int count, 677 FT_Pos width ) 678 { 679 int n; 680 FT_Pos best = 64 + 32 + 2; 681 FT_Pos reference = width; 682 FT_Pos scaled; 683 684 685 for ( n = 0; n < count; n++ ) 686 { 687 FT_Pos w; 688 FT_Pos dist; 689 690 691 w = widths[n].cur; 692 dist = width - w; 693 if ( dist < 0 ) 694 dist = -dist; 695 if ( dist < best ) 696 { 697 best = dist; 698 reference = w; 699 } 700 } 701 702 scaled = FT_PIX_ROUND( reference ); 703 704 if ( width >= reference ) 705 { 706 if ( width < scaled + 48 ) 707 width = reference; 708 } 709 else 710 { 711 if ( width > scaled - 48 ) 712 width = reference; 713 } 714 715 return width; 716 } 717 718 719 /* compute the snapped width of a given stem */ 720 721 static FT_Pos af_cjk_compute_stem_width(AF_GlyphHints hints,AF_Dimension dim,FT_Pos width,AF_Edge_Flags base_flags,AF_Edge_Flags stem_flags)722 af_cjk_compute_stem_width( AF_GlyphHints hints, 723 AF_Dimension dim, 724 FT_Pos width, 725 AF_Edge_Flags base_flags, 726 AF_Edge_Flags stem_flags ) 727 { 728 AF_LatinMetrics metrics = (AF_LatinMetrics) hints->metrics; 729 AF_LatinAxis axis = & metrics->axis[dim]; 730 FT_Pos dist = width; 731 FT_Int sign = 0; 732 FT_Int vertical = ( dim == AF_DIMENSION_VERT ); 733 734 FT_UNUSED( base_flags ); 735 FT_UNUSED( stem_flags ); 736 737 738 if ( !AF_LATIN_HINTS_DO_STEM_ADJUST( hints ) ) 739 return width; 740 741 if ( dist < 0 ) 742 { 743 dist = -width; 744 sign = 1; 745 } 746 747 if ( ( vertical && !AF_LATIN_HINTS_DO_VERT_SNAP( hints ) ) || 748 ( !vertical && !AF_LATIN_HINTS_DO_HORZ_SNAP( hints ) ) ) 749 { 750 /* smooth hinting process: very lightly quantize the stem width */ 751 752 if ( axis->width_count > 0 ) 753 { 754 if ( FT_ABS( dist - axis->widths[0].cur ) < 40 ) 755 { 756 dist = axis->widths[0].cur; 757 if ( dist < 48 ) 758 dist = 48; 759 760 goto Done_Width; 761 } 762 } 763 764 if ( dist < 54 ) 765 dist += ( 54 - dist ) / 2 ; 766 else if ( dist < 3 * 64 ) 767 { 768 FT_Pos delta; 769 770 771 delta = dist & 63; 772 dist &= -64; 773 774 if ( delta < 10 ) 775 dist += delta; 776 else if ( delta < 22 ) 777 dist += 10; 778 else if ( delta < 42 ) 779 dist += delta; 780 else if ( delta < 54 ) 781 dist += 54; 782 else 783 dist += delta; 784 } 785 } 786 else 787 { 788 /* strong hinting process: snap the stem width to integer pixels */ 789 790 dist = af_cjk_snap_width( axis->widths, axis->width_count, dist ); 791 792 if ( vertical ) 793 { 794 /* in the case of vertical hinting, always round */ 795 /* the stem heights to integer pixels */ 796 797 if ( dist >= 64 ) 798 dist = ( dist + 16 ) & ~63; 799 else 800 dist = 64; 801 } 802 else 803 { 804 if ( AF_LATIN_HINTS_DO_MONO( hints ) ) 805 { 806 /* monochrome horizontal hinting: snap widths to integer pixels */ 807 /* with a different threshold */ 808 809 if ( dist < 64 ) 810 dist = 64; 811 else 812 dist = ( dist + 32 ) & ~63; 813 } 814 else 815 { 816 /* for horizontal anti-aliased hinting, we adopt a more subtle */ 817 /* approach: we strengthen small stems, round stems whose size */ 818 /* is between 1 and 2 pixels to an integer, otherwise nothing */ 819 820 if ( dist < 48 ) 821 dist = ( dist + 64 ) >> 1; 822 823 else if ( dist < 128 ) 824 dist = ( dist + 22 ) & ~63; 825 else 826 /* round otherwise to prevent color fringes in LCD mode */ 827 dist = ( dist + 32 ) & ~63; 828 } 829 } 830 } 831 832 Done_Width: 833 if ( sign ) 834 dist = -dist; 835 836 return dist; 837 } 838 839 840 /* align one stem edge relative to the previous stem edge */ 841 842 static void af_cjk_align_linked_edge(AF_GlyphHints hints,AF_Dimension dim,AF_Edge base_edge,AF_Edge stem_edge)843 af_cjk_align_linked_edge( AF_GlyphHints hints, 844 AF_Dimension dim, 845 AF_Edge base_edge, 846 AF_Edge stem_edge ) 847 { 848 FT_Pos dist = stem_edge->opos - base_edge->opos; 849 850 FT_Pos fitted_width = af_cjk_compute_stem_width( 851 hints, dim, dist, 852 (AF_Edge_Flags)base_edge->flags, 853 (AF_Edge_Flags)stem_edge->flags ); 854 855 856 stem_edge->pos = base_edge->pos + fitted_width; 857 } 858 859 860 static void af_cjk_align_serif_edge(AF_GlyphHints hints,AF_Edge base,AF_Edge serif)861 af_cjk_align_serif_edge( AF_GlyphHints hints, 862 AF_Edge base, 863 AF_Edge serif ) 864 { 865 FT_UNUSED( hints ); 866 867 serif->pos = base->pos + ( serif->opos - base->opos ); 868 } 869 870 871 /*************************************************************************/ 872 /*************************************************************************/ 873 /*************************************************************************/ 874 /**** ****/ 875 /**** E D G E H I N T I N G ****/ 876 /**** ****/ 877 /*************************************************************************/ 878 /*************************************************************************/ 879 /*************************************************************************/ 880 881 882 #define AF_LIGHT_MODE_MAX_HORZ_GAP 9 883 #define AF_LIGHT_MODE_MAX_VERT_GAP 15 884 #define AF_LIGHT_MODE_MAX_DELTA_ABS 14 885 886 887 static FT_Pos af_hint_normal_stem(AF_GlyphHints hints,AF_Edge edge,AF_Edge edge2,FT_Pos anchor,AF_Dimension dim)888 af_hint_normal_stem( AF_GlyphHints hints, 889 AF_Edge edge, 890 AF_Edge edge2, 891 FT_Pos anchor, 892 AF_Dimension dim ) 893 { 894 FT_Pos org_len, cur_len, org_center; 895 FT_Pos cur_pos1, cur_pos2; 896 FT_Pos d_off1, u_off1, d_off2, u_off2, delta; 897 FT_Pos offset; 898 FT_Pos threshold = 64; 899 900 901 if ( !AF_LATIN_HINTS_DO_STEM_ADJUST( hints ) ) 902 { 903 if ( ( edge->flags & AF_EDGE_ROUND ) && 904 ( edge2->flags & AF_EDGE_ROUND ) ) 905 { 906 if ( dim == AF_DIMENSION_VERT ) 907 threshold = 64 - AF_LIGHT_MODE_MAX_HORZ_GAP; 908 else 909 threshold = 64 - AF_LIGHT_MODE_MAX_VERT_GAP; 910 } 911 else 912 { 913 if ( dim == AF_DIMENSION_VERT ) 914 threshold = 64 - AF_LIGHT_MODE_MAX_HORZ_GAP / 3; 915 else 916 threshold = 64 - AF_LIGHT_MODE_MAX_VERT_GAP / 3; 917 } 918 } 919 920 org_len = edge2->opos - edge->opos; 921 cur_len = af_cjk_compute_stem_width( hints, dim, org_len, 922 (AF_Edge_Flags)edge->flags, 923 (AF_Edge_Flags)edge2->flags ); 924 925 org_center = ( edge->opos + edge2->opos ) / 2 + anchor; 926 cur_pos1 = org_center - cur_len / 2; 927 cur_pos2 = cur_pos1 + cur_len; 928 d_off1 = cur_pos1 - FT_PIX_FLOOR( cur_pos1 ); 929 d_off2 = cur_pos2 - FT_PIX_FLOOR( cur_pos2 ); 930 u_off1 = 64 - d_off1; 931 u_off2 = 64 - d_off2; 932 delta = 0; 933 934 935 if ( d_off1 == 0 || d_off2 == 0 ) 936 goto Exit; 937 938 if ( cur_len <= threshold ) 939 { 940 if ( d_off2 < cur_len ) 941 { 942 if ( u_off1 <= d_off2 ) 943 delta = u_off1; 944 else 945 delta = -d_off2; 946 } 947 948 goto Exit; 949 } 950 951 if ( threshold < 64 ) 952 { 953 if ( d_off1 >= threshold || u_off1 >= threshold || 954 d_off2 >= threshold || u_off2 >= threshold ) 955 goto Exit; 956 } 957 958 offset = cur_len % 64; 959 960 if ( offset < 32 ) 961 { 962 if ( u_off1 <= offset || d_off2 <= offset ) 963 goto Exit; 964 } 965 else 966 offset = 64 - threshold; 967 968 d_off1 = threshold - u_off1; 969 u_off1 = u_off1 - offset; 970 u_off2 = threshold - d_off2; 971 d_off2 = d_off2 - offset; 972 973 if ( d_off1 <= u_off1 ) 974 u_off1 = -d_off1; 975 976 if ( d_off2 <= u_off2 ) 977 u_off2 = -d_off2; 978 979 if ( FT_ABS( u_off1 ) <= FT_ABS( u_off2 ) ) 980 delta = u_off1; 981 else 982 delta = u_off2; 983 984 Exit: 985 986 #if 1 987 if ( !AF_LATIN_HINTS_DO_STEM_ADJUST( hints ) ) 988 { 989 if ( delta > AF_LIGHT_MODE_MAX_DELTA_ABS ) 990 delta = AF_LIGHT_MODE_MAX_DELTA_ABS; 991 else if ( delta < -AF_LIGHT_MODE_MAX_DELTA_ABS ) 992 delta = -AF_LIGHT_MODE_MAX_DELTA_ABS; 993 } 994 #endif 995 996 cur_pos1 += delta; 997 998 if ( edge->opos < edge2->opos ) 999 { 1000 edge->pos = cur_pos1; 1001 edge2->pos = cur_pos1 + cur_len; 1002 } 1003 else 1004 { 1005 edge->pos = cur_pos1 + cur_len; 1006 edge2->pos = cur_pos1; 1007 } 1008 1009 return delta; 1010 } 1011 1012 1013 static void af_cjk_hint_edges(AF_GlyphHints hints,AF_Dimension dim)1014 af_cjk_hint_edges( AF_GlyphHints hints, 1015 AF_Dimension dim ) 1016 { 1017 AF_AxisHints axis = &hints->axis[dim]; 1018 AF_Edge edges = axis->edges; 1019 AF_Edge edge_limit = edges + axis->num_edges; 1020 FT_Int n_edges; 1021 AF_Edge edge; 1022 AF_Edge anchor = 0; 1023 FT_Pos delta = 0; 1024 FT_Int skipped = 0; 1025 1026 1027 /* now we align all stem edges. */ 1028 for ( edge = edges; edge < edge_limit; edge++ ) 1029 { 1030 AF_Edge edge2; 1031 1032 1033 if ( edge->flags & AF_EDGE_DONE ) 1034 continue; 1035 1036 /* skip all non-stem edges */ 1037 edge2 = edge->link; 1038 if ( !edge2 ) 1039 { 1040 skipped++; 1041 continue; 1042 } 1043 1044 /* now align the stem */ 1045 1046 if ( edge2 < edge ) 1047 { 1048 af_cjk_align_linked_edge( hints, dim, edge2, edge ); 1049 edge->flags |= AF_EDGE_DONE; 1050 continue; 1051 } 1052 1053 if ( dim != AF_DIMENSION_VERT && !anchor ) 1054 { 1055 1056 #if 0 1057 if ( fixedpitch ) 1058 { 1059 AF_Edge left = edge; 1060 AF_Edge right = edge_limit - 1; 1061 AF_EdgeRec left1, left2, right1, right2; 1062 FT_Pos target, center1, center2; 1063 FT_Pos delta1, delta2, d1, d2; 1064 1065 1066 while ( right > left && !right->link ) 1067 right--; 1068 1069 left1 = *left; 1070 left2 = *left->link; 1071 right1 = *right->link; 1072 right2 = *right; 1073 1074 delta = ( ( ( hinter->pp2.x + 32 ) & -64 ) - hinter->pp2.x ) / 2; 1075 target = left->opos + ( right->opos - left->opos ) / 2 + delta - 16; 1076 1077 delta1 = delta; 1078 delta1 += af_hint_normal_stem( hints, left, left->link, 1079 delta1, 0 ); 1080 1081 if ( left->link != right ) 1082 af_hint_normal_stem( hints, right->link, right, delta1, 0 ); 1083 1084 center1 = left->pos + ( right->pos - left->pos ) / 2; 1085 1086 if ( center1 >= target ) 1087 delta2 = delta - 32; 1088 else 1089 delta2 = delta + 32; 1090 1091 delta2 += af_hint_normal_stem( hints, &left1, &left2, delta2, 0 ); 1092 1093 if ( delta1 != delta2 ) 1094 { 1095 if ( left->link != right ) 1096 af_hint_normal_stem( hints, &right1, &right2, delta2, 0 ); 1097 1098 center2 = left1.pos + ( right2.pos - left1.pos ) / 2; 1099 1100 d1 = center1 - target; 1101 d2 = center2 - target; 1102 1103 if ( FT_ABS( d2 ) < FT_ABS( d1 ) ) 1104 { 1105 left->pos = left1.pos; 1106 left->link->pos = left2.pos; 1107 1108 if ( left->link != right ) 1109 { 1110 right->link->pos = right1.pos; 1111 right->pos = right2.pos; 1112 } 1113 1114 delta1 = delta2; 1115 } 1116 } 1117 1118 delta = delta1; 1119 right->link->flags |= AF_EDGE_DONE; 1120 right->flags |= AF_EDGE_DONE; 1121 } 1122 else 1123 1124 #endif /* 0 */ 1125 1126 delta = af_hint_normal_stem( hints, edge, edge2, 0, 1127 AF_DIMENSION_HORZ ); 1128 } 1129 else 1130 af_hint_normal_stem( hints, edge, edge2, delta, dim ); 1131 1132 #if 0 1133 printf( "stem (%d,%d) adjusted (%.1f,%.1f)\n", 1134 edge - edges, edge2 - edges, 1135 ( edge->pos - edge->opos ) / 64.0, 1136 ( edge2->pos - edge2->opos ) / 64.0 ); 1137 #endif 1138 1139 anchor = edge; 1140 edge->flags |= AF_EDGE_DONE; 1141 edge2->flags |= AF_EDGE_DONE; 1142 } 1143 1144 /* make sure that lowercase m's maintain their symmetry */ 1145 1146 /* In general, lowercase m's have six vertical edges if they are sans */ 1147 /* serif, or twelve if they are with serifs. This implementation is */ 1148 /* based on that assumption, and seems to work very well with most */ 1149 /* faces. However, if for a certain face this assumption is not */ 1150 /* true, the m is just rendered like before. In addition, any stem */ 1151 /* correction will only be applied to symmetrical glyphs (even if the */ 1152 /* glyph is not an m), so the potential for unwanted distortion is */ 1153 /* relatively low. */ 1154 1155 /* We don't handle horizontal edges since we can't easily assure that */ 1156 /* the third (lowest) stem aligns with the base line; it might end up */ 1157 /* one pixel higher or lower. */ 1158 1159 n_edges = edge_limit - edges; 1160 if ( dim == AF_DIMENSION_HORZ && ( n_edges == 6 || n_edges == 12 ) ) 1161 { 1162 AF_Edge edge1, edge2, edge3; 1163 FT_Pos dist1, dist2, span; 1164 1165 1166 if ( n_edges == 6 ) 1167 { 1168 edge1 = edges; 1169 edge2 = edges + 2; 1170 edge3 = edges + 4; 1171 } 1172 else 1173 { 1174 edge1 = edges + 1; 1175 edge2 = edges + 5; 1176 edge3 = edges + 9; 1177 } 1178 1179 dist1 = edge2->opos - edge1->opos; 1180 dist2 = edge3->opos - edge2->opos; 1181 1182 span = dist1 - dist2; 1183 if ( span < 0 ) 1184 span = -span; 1185 1186 if ( edge1->link == edge1 + 1 && 1187 edge2->link == edge2 + 1 && 1188 edge3->link == edge3 + 1 && span < 8 ) 1189 { 1190 delta = edge3->pos - ( 2 * edge2->pos - edge1->pos ); 1191 edge3->pos -= delta; 1192 if ( edge3->link ) 1193 edge3->link->pos -= delta; 1194 1195 /* move the serifs along with the stem */ 1196 if ( n_edges == 12 ) 1197 { 1198 ( edges + 8 )->pos -= delta; 1199 ( edges + 11 )->pos -= delta; 1200 } 1201 1202 edge3->flags |= AF_EDGE_DONE; 1203 if ( edge3->link ) 1204 edge3->link->flags |= AF_EDGE_DONE; 1205 } 1206 } 1207 1208 if ( !skipped ) 1209 return; 1210 1211 /* 1212 * now hint the remaining edges (serifs and single) in order 1213 * to complete our processing 1214 */ 1215 for ( edge = edges; edge < edge_limit; edge++ ) 1216 { 1217 if ( edge->flags & AF_EDGE_DONE ) 1218 continue; 1219 1220 if ( edge->serif ) 1221 { 1222 af_cjk_align_serif_edge( hints, edge->serif, edge ); 1223 edge->flags |= AF_EDGE_DONE; 1224 skipped--; 1225 } 1226 } 1227 1228 if ( !skipped ) 1229 return; 1230 1231 for ( edge = edges; edge < edge_limit; edge++ ) 1232 { 1233 AF_Edge before, after; 1234 1235 1236 if ( edge->flags & AF_EDGE_DONE ) 1237 continue; 1238 1239 before = after = edge; 1240 1241 while ( --before >= edges ) 1242 if ( before->flags & AF_EDGE_DONE ) 1243 break; 1244 1245 while ( ++after < edge_limit ) 1246 if ( after->flags & AF_EDGE_DONE ) 1247 break; 1248 1249 if ( before >= edges || after < edge_limit ) 1250 { 1251 if ( before < edges ) 1252 af_cjk_align_serif_edge( hints, after, edge ); 1253 else if ( after >= edge_limit ) 1254 af_cjk_align_serif_edge( hints, before, edge ); 1255 else 1256 { 1257 if ( after->fpos == before->fpos ) 1258 edge->pos = before->pos; 1259 else 1260 edge->pos = before->pos + 1261 FT_MulDiv( edge->fpos - before->fpos, 1262 after->pos - before->pos, 1263 after->fpos - before->fpos ); 1264 } 1265 } 1266 } 1267 } 1268 1269 1270 static void af_cjk_align_edge_points(AF_GlyphHints hints,AF_Dimension dim)1271 af_cjk_align_edge_points( AF_GlyphHints hints, 1272 AF_Dimension dim ) 1273 { 1274 AF_AxisHints axis = & hints->axis[dim]; 1275 AF_Edge edges = axis->edges; 1276 AF_Edge edge_limit = edges + axis->num_edges; 1277 AF_Edge edge; 1278 FT_Bool snapping; 1279 1280 1281 snapping = FT_BOOL( ( dim == AF_DIMENSION_HORZ && 1282 AF_LATIN_HINTS_DO_HORZ_SNAP( hints ) ) || 1283 ( dim == AF_DIMENSION_VERT && 1284 AF_LATIN_HINTS_DO_VERT_SNAP( hints ) ) ); 1285 1286 for ( edge = edges; edge < edge_limit; edge++ ) 1287 { 1288 /* move the points of each segment */ 1289 /* in each edge to the edge's position */ 1290 AF_Segment seg = edge->first; 1291 1292 1293 if ( snapping ) 1294 { 1295 do 1296 { 1297 AF_Point point = seg->first; 1298 1299 1300 for (;;) 1301 { 1302 if ( dim == AF_DIMENSION_HORZ ) 1303 { 1304 point->x = edge->pos; 1305 point->flags |= AF_FLAG_TOUCH_X; 1306 } 1307 else 1308 { 1309 point->y = edge->pos; 1310 point->flags |= AF_FLAG_TOUCH_Y; 1311 } 1312 1313 if ( point == seg->last ) 1314 break; 1315 1316 point = point->next; 1317 } 1318 1319 seg = seg->edge_next; 1320 1321 } while ( seg != edge->first ); 1322 } 1323 else 1324 { 1325 FT_Pos delta = edge->pos - edge->opos; 1326 1327 1328 do 1329 { 1330 AF_Point point = seg->first; 1331 1332 1333 for (;;) 1334 { 1335 if ( dim == AF_DIMENSION_HORZ ) 1336 { 1337 point->x += delta; 1338 point->flags |= AF_FLAG_TOUCH_X; 1339 } 1340 else 1341 { 1342 point->y += delta; 1343 point->flags |= AF_FLAG_TOUCH_Y; 1344 } 1345 1346 if ( point == seg->last ) 1347 break; 1348 1349 point = point->next; 1350 } 1351 1352 seg = seg->edge_next; 1353 1354 } while ( seg != edge->first ); 1355 } 1356 } 1357 } 1358 1359 1360 FT_LOCAL_DEF( FT_Error ) af_cjk_hints_apply(AF_GlyphHints hints,FT_Outline * outline,AF_LatinMetrics metrics)1361 af_cjk_hints_apply( AF_GlyphHints hints, 1362 FT_Outline* outline, 1363 AF_LatinMetrics metrics ) 1364 { 1365 FT_Error error; 1366 int dim; 1367 1368 FT_UNUSED( metrics ); 1369 1370 1371 error = af_glyph_hints_reload( hints, outline, 0 ); 1372 if ( error ) 1373 goto Exit; 1374 1375 /* analyze glyph outline */ 1376 if ( AF_HINTS_DO_HORIZONTAL( hints ) ) 1377 { 1378 error = af_cjk_hints_detect_features( hints, AF_DIMENSION_HORZ ); 1379 if ( error ) 1380 goto Exit; 1381 } 1382 1383 if ( AF_HINTS_DO_VERTICAL( hints ) ) 1384 { 1385 error = af_cjk_hints_detect_features( hints, AF_DIMENSION_VERT ); 1386 if ( error ) 1387 goto Exit; 1388 } 1389 1390 /* grid-fit the outline */ 1391 for ( dim = 0; dim < AF_DIMENSION_MAX; dim++ ) 1392 { 1393 if ( ( dim == AF_DIMENSION_HORZ && AF_HINTS_DO_HORIZONTAL( hints ) ) || 1394 ( dim == AF_DIMENSION_VERT && AF_HINTS_DO_VERTICAL( hints ) ) ) 1395 { 1396 1397 #ifdef AF_USE_WARPER 1398 if ( dim == AF_DIMENSION_HORZ && 1399 metrics->root.scaler.render_mode == FT_RENDER_MODE_NORMAL ) 1400 { 1401 AF_WarperRec warper; 1402 FT_Fixed scale; 1403 FT_Pos delta; 1404 1405 1406 af_warper_compute( &warper, hints, dim, &scale, &delta ); 1407 af_glyph_hints_scale_dim( hints, dim, scale, delta ); 1408 continue; 1409 } 1410 #endif /* AF_USE_WARPER */ 1411 1412 af_cjk_hint_edges( hints, (AF_Dimension)dim ); 1413 af_cjk_align_edge_points( hints, (AF_Dimension)dim ); 1414 af_glyph_hints_align_strong_points( hints, (AF_Dimension)dim ); 1415 af_glyph_hints_align_weak_points( hints, (AF_Dimension)dim ); 1416 } 1417 } 1418 1419 #if 0 1420 af_glyph_hints_dump_points( hints ); 1421 af_glyph_hints_dump_segments( hints ); 1422 af_glyph_hints_dump_edges( hints ); 1423 #endif 1424 1425 af_glyph_hints_save( hints, outline ); 1426 1427 Exit: 1428 return error; 1429 } 1430 1431 1432 /*************************************************************************/ 1433 /*************************************************************************/ 1434 /***** *****/ 1435 /***** C J K S C R I P T C L A S S *****/ 1436 /***** *****/ 1437 /*************************************************************************/ 1438 /*************************************************************************/ 1439 1440 1441 static const AF_Script_UniRangeRec af_cjk_uniranges[] = 1442 { 1443 #if 0 1444 { 0x0100UL, 0xFFFFUL }, /* why this? */ 1445 #endif 1446 { 0x2E80UL, 0x2EFFUL }, /* CJK Radicals Supplement */ 1447 { 0x2F00UL, 0x2FDFUL }, /* Kangxi Radicals */ 1448 { 0x3000UL, 0x303FUL }, /* CJK Symbols and Punctuation */ 1449 { 0x3040UL, 0x309FUL }, /* Hiragana */ 1450 { 0x30A0UL, 0x30FFUL }, /* Katakana */ 1451 { 0x3100UL, 0x312FUL }, /* Bopomofo */ 1452 { 0x3130UL, 0x318FUL }, /* Hangul Compatibility Jamo */ 1453 { 0x31A0UL, 0x31BFUL }, /* Bopomofo Extended */ 1454 { 0x31C0UL, 0x31EFUL }, /* CJK Strokes */ 1455 { 0x31F0UL, 0x31FFUL }, /* Katakana Phonetic Extensions */ 1456 { 0x3200UL, 0x32FFUL }, /* Enclosed CJK Letters and Months */ 1457 { 0x3300UL, 0x33FFUL }, /* CJK Compatibility */ 1458 { 0x3400UL, 0x4DBFUL }, /* CJK Unified Ideographs Extension A */ 1459 { 0x4DC0UL, 0x4DFFUL }, /* Yijing Hexagram Symbols */ 1460 { 0x4E00UL, 0x9FFFUL }, /* CJK Unified Ideographs */ 1461 { 0xF900UL, 0xFAFFUL }, /* CJK Compatibility Ideographs */ 1462 { 0xFE30UL, 0xFE4FUL }, /* CJK Compatibility Forms */ 1463 { 0xFF00UL, 0xFFEFUL }, /* Halfwidth and Fullwidth Forms */ 1464 { 0x20000UL, 0x2A6DFUL }, /* CJK Unified Ideographs Extension B */ 1465 { 0x2F800UL, 0x2FA1FUL }, /* CJK Compatibility Ideographs Supplement */ 1466 { 0UL, 0UL } 1467 }; 1468 1469 1470 FT_CALLBACK_TABLE_DEF const AF_ScriptClassRec 1471 af_cjk_script_class = 1472 { 1473 AF_SCRIPT_CJK, 1474 af_cjk_uniranges, 1475 1476 sizeof( AF_LatinMetricsRec ), 1477 1478 (AF_Script_InitMetricsFunc) af_cjk_metrics_init, 1479 (AF_Script_ScaleMetricsFunc)af_cjk_metrics_scale, 1480 (AF_Script_DoneMetricsFunc) NULL, 1481 1482 (AF_Script_InitHintsFunc) af_cjk_hints_init, 1483 (AF_Script_ApplyHintsFunc) af_cjk_hints_apply 1484 }; 1485 1486 #else /* !AF_CONFIG_OPTION_CJK */ 1487 1488 static const AF_Script_UniRangeRec af_cjk_uniranges[] = 1489 { 1490 { 0, 0 } 1491 }; 1492 1493 1494 FT_CALLBACK_TABLE_DEF const AF_ScriptClassRec 1495 af_cjk_script_class = 1496 { 1497 AF_SCRIPT_CJK, 1498 af_cjk_uniranges, 1499 1500 sizeof( AF_LatinMetricsRec ), 1501 1502 (AF_Script_InitMetricsFunc) NULL, 1503 (AF_Script_ScaleMetricsFunc)NULL, 1504 (AF_Script_DoneMetricsFunc) NULL, 1505 1506 (AF_Script_InitHintsFunc) NULL, 1507 (AF_Script_ApplyHintsFunc) NULL 1508 }; 1509 1510 #endif /* !AF_CONFIG_OPTION_CJK */ 1511 1512 1513 /* END */ 1514