1 /**************************************************************************** 2 * 3 * aflatin.c 4 * 5 * Auto-fitter hinting routines for latin writing system (body). 6 * 7 * Copyright (C) 2003-2023 by 8 * David Turner, Robert Wilhelm, and Werner Lemberg. 9 * 10 * This file is part of the FreeType project, and may only be used, 11 * modified, and distributed under the terms of the FreeType project 12 * license, LICENSE.TXT. By continuing to use, modify, or distribute 13 * this file you indicate that you have read the license and 14 * understand and accept it fully. 15 * 16 */ 17 18 19 #include <freetype/ftadvanc.h> 20 #include <freetype/internal/ftdebug.h> 21 22 #include "afglobal.h" 23 #include "aflatin.h" 24 #include "aferrors.h" 25 26 27 /************************************************************************** 28 * 29 * The macro FT_COMPONENT is used in trace mode. It is an implicit 30 * parameter of the FT_TRACE() and FT_ERROR() macros, used to print/log 31 * messages during execution. 32 */ 33 #undef FT_COMPONENT 34 #define FT_COMPONENT aflatin 35 36 37 /* needed for computation of round vs. flat segments */ 38 #define FLAT_THRESHOLD( x ) ( x / 14 ) 39 40 41 /*************************************************************************/ 42 /*************************************************************************/ 43 /***** *****/ 44 /***** L A T I N G L O B A L M E T R I C S *****/ 45 /***** *****/ 46 /*************************************************************************/ 47 /*************************************************************************/ 48 49 50 /* Find segments and links, compute all stem widths, and initialize */ 51 /* standard width and height for the glyph with given charcode. */ 52 53 FT_LOCAL_DEF( void ) af_latin_metrics_init_widths(AF_LatinMetrics metrics,FT_Face face)54 af_latin_metrics_init_widths( AF_LatinMetrics metrics, 55 FT_Face face ) 56 { 57 /* scan the array of segments in each direction */ 58 AF_GlyphHintsRec hints[1]; 59 60 61 FT_TRACE5(( "\n" )); 62 FT_TRACE5(( "latin standard widths computation (style `%s')\n", 63 af_style_names[metrics->root.style_class->style] )); 64 FT_TRACE5(( "=====================================================\n" )); 65 FT_TRACE5(( "\n" )); 66 67 af_glyph_hints_init( hints, face->memory ); 68 69 metrics->axis[AF_DIMENSION_HORZ].width_count = 0; 70 metrics->axis[AF_DIMENSION_VERT].width_count = 0; 71 72 { 73 FT_Error error; 74 FT_ULong glyph_index; 75 int dim; 76 AF_LatinMetricsRec dummy[1]; 77 AF_Scaler scaler = &dummy->root.scaler; 78 79 AF_StyleClass style_class = metrics->root.style_class; 80 AF_ScriptClass script_class = af_script_classes[style_class->script]; 81 82 /* If HarfBuzz is not available, we need a pointer to a single */ 83 /* unsigned long value. */ 84 #ifdef FT_CONFIG_OPTION_USE_HARFBUZZ 85 void* shaper_buf; 86 #else 87 FT_ULong shaper_buf_; 88 void* shaper_buf = &shaper_buf_; 89 #endif 90 91 const char* p; 92 93 #ifdef FT_DEBUG_LEVEL_TRACE 94 FT_ULong ch = 0; 95 #endif 96 97 98 p = script_class->standard_charstring; 99 100 #ifdef FT_CONFIG_OPTION_USE_HARFBUZZ 101 shaper_buf = af_shaper_buf_create( face ); 102 #endif 103 /* 104 * We check a list of standard characters to catch features like 105 * `c2sc' (small caps from caps) that don't contain lowercase letters 106 * by definition, or other features that mainly operate on numerals. 107 * The first match wins. 108 */ 109 110 glyph_index = 0; 111 while ( *p ) 112 { 113 unsigned int num_idx; 114 115 #ifdef FT_DEBUG_LEVEL_TRACE 116 const char* p_old; 117 #endif 118 119 120 while ( *p == ' ' ) 121 p++; 122 123 #ifdef FT_DEBUG_LEVEL_TRACE 124 p_old = p; 125 GET_UTF8_CHAR( ch, p_old ); 126 #endif 127 128 /* reject input that maps to more than a single glyph */ 129 p = af_shaper_get_cluster( p, &metrics->root, shaper_buf, &num_idx ); 130 if ( num_idx > 1 ) 131 continue; 132 133 /* otherwise exit loop if we have a result */ 134 glyph_index = af_shaper_get_elem( &metrics->root, 135 shaper_buf, 136 0, 137 NULL, 138 NULL ); 139 if ( glyph_index ) 140 break; 141 } 142 143 af_shaper_buf_destroy( face, shaper_buf ); 144 145 if ( !glyph_index ) 146 { 147 FT_TRACE5(( "standard character missing;" 148 " using fallback stem widths\n" )); 149 goto Exit; 150 } 151 152 FT_TRACE5(( "standard character: U+%04lX (glyph index %ld)\n", 153 ch, glyph_index )); 154 155 error = FT_Load_Glyph( face, glyph_index, FT_LOAD_NO_SCALE ); 156 if ( error || face->glyph->outline.n_points <= 0 ) 157 goto Exit; 158 159 FT_ZERO( dummy ); 160 161 dummy->units_per_em = metrics->units_per_em; 162 163 scaler->x_scale = 0x10000L; 164 scaler->y_scale = 0x10000L; 165 scaler->x_delta = 0; 166 scaler->y_delta = 0; 167 168 scaler->face = face; 169 scaler->render_mode = FT_RENDER_MODE_NORMAL; 170 scaler->flags = 0; 171 172 af_glyph_hints_rescale( hints, (AF_StyleMetrics)dummy ); 173 174 error = af_glyph_hints_reload( hints, &face->glyph->outline ); 175 if ( error ) 176 goto Exit; 177 178 for ( dim = 0; dim < AF_DIMENSION_MAX; dim++ ) 179 { 180 AF_LatinAxis axis = &metrics->axis[dim]; 181 AF_AxisHints axhints = &hints->axis[dim]; 182 AF_Segment seg, limit, link; 183 FT_UInt num_widths = 0; 184 185 186 error = af_latin_hints_compute_segments( hints, 187 (AF_Dimension)dim ); 188 if ( error ) 189 goto Exit; 190 191 /* 192 * We assume that the glyphs selected for the stem width 193 * computation are `featureless' enough so that the linking 194 * algorithm works fine without adjustments of its scoring 195 * function. 196 */ 197 af_latin_hints_link_segments( hints, 198 0, 199 NULL, 200 (AF_Dimension)dim ); 201 202 seg = axhints->segments; 203 limit = FT_OFFSET( seg, axhints->num_segments ); 204 205 for ( ; seg < limit; seg++ ) 206 { 207 link = seg->link; 208 209 /* we only consider stem segments there! */ 210 if ( link && link->link == seg && link > seg ) 211 { 212 FT_Pos dist; 213 214 215 dist = seg->pos - link->pos; 216 if ( dist < 0 ) 217 dist = -dist; 218 219 if ( num_widths < AF_LATIN_MAX_WIDTHS ) 220 axis->widths[num_widths++].org = dist; 221 } 222 } 223 224 /* this also replaces multiple almost identical stem widths */ 225 /* with a single one (the value 100 is heuristic) */ 226 af_sort_and_quantize_widths( &num_widths, axis->widths, 227 dummy->units_per_em / 100 ); 228 axis->width_count = num_widths; 229 } 230 231 Exit: 232 for ( dim = 0; dim < AF_DIMENSION_MAX; dim++ ) 233 { 234 AF_LatinAxis axis = &metrics->axis[dim]; 235 FT_Pos stdw; 236 237 238 stdw = ( axis->width_count > 0 ) ? axis->widths[0].org 239 : AF_LATIN_CONSTANT( metrics, 50 ); 240 241 /* let's try 20% of the smallest width */ 242 axis->edge_distance_threshold = stdw / 5; 243 axis->standard_width = stdw; 244 axis->extra_light = 0; 245 246 #ifdef FT_DEBUG_LEVEL_TRACE 247 { 248 FT_UInt i; 249 250 251 FT_TRACE5(( "%s widths:\n", 252 dim == AF_DIMENSION_VERT ? "horizontal" 253 : "vertical" )); 254 255 FT_TRACE5(( " %ld (standard)", axis->standard_width )); 256 for ( i = 1; i < axis->width_count; i++ ) 257 FT_TRACE5(( " %ld", axis->widths[i].org )); 258 259 FT_TRACE5(( "\n" )); 260 } 261 #endif 262 } 263 } 264 265 FT_TRACE5(( "\n" )); 266 267 af_glyph_hints_done( hints ); 268 } 269 270 271 static void af_latin_sort_blue(FT_UInt count,AF_LatinBlue * table)272 af_latin_sort_blue( FT_UInt count, 273 AF_LatinBlue* table ) 274 { 275 FT_UInt i, j; 276 AF_LatinBlue swap; 277 278 279 /* we sort from bottom to top */ 280 for ( i = 1; i < count; i++ ) 281 { 282 for ( j = i; j > 0; j-- ) 283 { 284 FT_Pos a, b; 285 286 287 if ( table[j - 1]->flags & ( AF_LATIN_BLUE_TOP | 288 AF_LATIN_BLUE_SUB_TOP ) ) 289 a = table[j - 1]->ref.org; 290 else 291 a = table[j - 1]->shoot.org; 292 293 if ( table[j]->flags & ( AF_LATIN_BLUE_TOP | 294 AF_LATIN_BLUE_SUB_TOP ) ) 295 b = table[j]->ref.org; 296 else 297 b = table[j]->shoot.org; 298 299 if ( b >= a ) 300 break; 301 302 swap = table[j]; 303 table[j] = table[j - 1]; 304 table[j - 1] = swap; 305 } 306 } 307 } 308 309 310 /* Find all blue zones. Flat segments give the reference points, */ 311 /* round segments the overshoot positions. */ 312 313 static int af_latin_metrics_init_blues(AF_LatinMetrics metrics,FT_Face face)314 af_latin_metrics_init_blues( AF_LatinMetrics metrics, 315 FT_Face face ) 316 { 317 FT_Pos flats [AF_BLUE_STRING_MAX_LEN]; 318 FT_Pos rounds[AF_BLUE_STRING_MAX_LEN]; 319 320 FT_UInt num_flats; 321 FT_UInt num_rounds; 322 323 AF_LatinBlue blue; 324 FT_Error error; 325 AF_LatinAxis axis = &metrics->axis[AF_DIMENSION_VERT]; 326 FT_Outline outline; 327 328 AF_StyleClass sc = metrics->root.style_class; 329 330 AF_Blue_Stringset bss = sc->blue_stringset; 331 const AF_Blue_StringRec* bs = &af_blue_stringsets[bss]; 332 333 FT_Pos flat_threshold = FLAT_THRESHOLD( metrics->units_per_em ); 334 335 /* If HarfBuzz is not available, we need a pointer to a single */ 336 /* unsigned long value. */ 337 #ifdef FT_CONFIG_OPTION_USE_HARFBUZZ 338 void* shaper_buf; 339 #else 340 FT_ULong shaper_buf_; 341 void* shaper_buf = &shaper_buf_; 342 #endif 343 344 345 /* we walk over the blue character strings as specified in the */ 346 /* style's entry in the `af_blue_stringset' array */ 347 348 FT_TRACE5(( "latin blue zones computation\n" )); 349 FT_TRACE5(( "============================\n" )); 350 FT_TRACE5(( "\n" )); 351 352 #ifdef FT_CONFIG_OPTION_USE_HARFBUZZ 353 shaper_buf = af_shaper_buf_create( face ); 354 #endif 355 356 for ( ; bs->string != AF_BLUE_STRING_MAX; bs++ ) 357 { 358 const char* p = &af_blue_strings[bs->string]; 359 FT_Pos* blue_ref; 360 FT_Pos* blue_shoot; 361 FT_Pos ascender; 362 FT_Pos descender; 363 364 365 #ifdef FT_DEBUG_LEVEL_TRACE 366 { 367 FT_Bool have_flag = 0; 368 369 370 FT_TRACE5(( "blue zone %d", axis->blue_count )); 371 372 if ( bs->properties ) 373 { 374 FT_TRACE5(( " (" )); 375 376 if ( AF_LATIN_IS_TOP_BLUE( bs ) ) 377 { 378 FT_TRACE5(( "top" )); 379 have_flag = 1; 380 } 381 else if ( AF_LATIN_IS_SUB_TOP_BLUE( bs ) ) 382 { 383 FT_TRACE5(( "sub top" )); 384 have_flag = 1; 385 } 386 387 if ( AF_LATIN_IS_NEUTRAL_BLUE( bs ) ) 388 { 389 if ( have_flag ) 390 FT_TRACE5(( ", " )); 391 FT_TRACE5(( "neutral" )); 392 have_flag = 1; 393 } 394 395 if ( AF_LATIN_IS_X_HEIGHT_BLUE( bs ) ) 396 { 397 if ( have_flag ) 398 FT_TRACE5(( ", " )); 399 FT_TRACE5(( "small top" )); 400 have_flag = 1; 401 } 402 403 if ( AF_LATIN_IS_LONG_BLUE( bs ) ) 404 { 405 if ( have_flag ) 406 FT_TRACE5(( ", " )); 407 FT_TRACE5(( "long" )); 408 } 409 410 FT_TRACE5(( ")" )); 411 } 412 413 FT_TRACE5(( ":\n" )); 414 } 415 #endif /* FT_DEBUG_LEVEL_TRACE */ 416 417 num_flats = 0; 418 num_rounds = 0; 419 ascender = 0; 420 descender = 0; 421 422 while ( *p ) 423 { 424 FT_ULong glyph_index; 425 FT_Long y_offset; 426 FT_Int best_point, best_contour_first, best_contour_last; 427 FT_Vector* points; 428 429 FT_Pos best_y_extremum; /* same as points.y */ 430 FT_Bool best_round = 0; 431 432 unsigned int i, num_idx; 433 434 #ifdef FT_DEBUG_LEVEL_TRACE 435 const char* p_old; 436 FT_ULong ch; 437 #endif 438 439 440 while ( *p == ' ' ) 441 p++; 442 443 #ifdef FT_DEBUG_LEVEL_TRACE 444 p_old = p; 445 GET_UTF8_CHAR( ch, p_old ); 446 #endif 447 448 p = af_shaper_get_cluster( p, &metrics->root, shaper_buf, &num_idx ); 449 450 if ( !num_idx ) 451 { 452 FT_TRACE5(( " U+%04lX unavailable\n", ch )); 453 continue; 454 } 455 456 if ( AF_LATIN_IS_TOP_BLUE( bs ) ) 457 best_y_extremum = FT_INT_MIN; 458 else 459 best_y_extremum = FT_INT_MAX; 460 461 /* iterate over all glyph elements of the character cluster */ 462 /* and get the data of the `biggest' one */ 463 for ( i = 0; i < num_idx; i++ ) 464 { 465 FT_Pos best_y; 466 FT_Bool round = 0; 467 468 469 /* load the character in the face -- skip unknown or empty ones */ 470 glyph_index = af_shaper_get_elem( &metrics->root, 471 shaper_buf, 472 i, 473 NULL, 474 &y_offset ); 475 if ( glyph_index == 0 ) 476 { 477 FT_TRACE5(( " U+%04lX unavailable\n", ch )); 478 continue; 479 } 480 481 error = FT_Load_Glyph( face, glyph_index, FT_LOAD_NO_SCALE ); 482 outline = face->glyph->outline; 483 /* reject glyphs that don't produce any rendering */ 484 if ( error || outline.n_points <= 2 ) 485 { 486 #ifdef FT_DEBUG_LEVEL_TRACE 487 if ( num_idx == 1 ) 488 FT_TRACE5(( " U+%04lX contains no (usable) outlines\n", ch )); 489 else 490 FT_TRACE5(( " component %d of cluster starting with U+%04lX" 491 " contains no (usable) outlines\n", i, ch )); 492 #endif 493 continue; 494 } 495 496 /* now compute min or max point indices and coordinates */ 497 points = outline.points; 498 best_point = -1; 499 best_contour_first = -1; 500 best_contour_last = -1; 501 best_y = 0; /* make compiler happy */ 502 503 { 504 FT_Int nn; 505 FT_Int pp, first, last; 506 507 508 last = -1; 509 for ( nn = 0; nn < outline.n_contours; nn++ ) 510 { 511 first = last + 1; 512 last = outline.contours[nn]; 513 514 /* Avoid single-point contours since they are never */ 515 /* rasterized. In some fonts, they correspond to mark */ 516 /* attachment points that are way outside of the glyph's */ 517 /* real outline. */ 518 if ( last <= first ) 519 continue; 520 521 if ( AF_LATIN_IS_TOP_BLUE( bs ) || 522 AF_LATIN_IS_SUB_TOP_BLUE( bs ) ) 523 { 524 for ( pp = first; pp <= last; pp++ ) 525 { 526 if ( best_point < 0 || points[pp].y > best_y ) 527 { 528 best_point = pp; 529 best_y = points[pp].y; 530 ascender = FT_MAX( ascender, best_y + y_offset ); 531 } 532 else 533 descender = FT_MIN( descender, points[pp].y + y_offset ); 534 } 535 } 536 else 537 { 538 for ( pp = first; pp <= last; pp++ ) 539 { 540 if ( best_point < 0 || points[pp].y < best_y ) 541 { 542 best_point = pp; 543 best_y = points[pp].y; 544 descender = FT_MIN( descender, best_y + y_offset ); 545 } 546 else 547 ascender = FT_MAX( ascender, points[pp].y + y_offset ); 548 } 549 } 550 551 if ( best_point > best_contour_last ) 552 { 553 best_contour_first = first; 554 best_contour_last = last; 555 } 556 } 557 } 558 559 /* now check whether the point belongs to a straight or round */ 560 /* segment; we first need to find in which contour the extremum */ 561 /* lies, then inspect its previous and next points */ 562 if ( best_point >= 0 ) 563 { 564 FT_Pos best_x = points[best_point].x; 565 FT_Int prev, next; 566 FT_Int best_segment_first, best_segment_last; 567 FT_Int best_on_point_first, best_on_point_last; 568 FT_Pos dist; 569 570 571 best_segment_first = best_point; 572 best_segment_last = best_point; 573 574 if ( FT_CURVE_TAG( outline.tags[best_point] ) == FT_CURVE_TAG_ON ) 575 { 576 best_on_point_first = best_point; 577 best_on_point_last = best_point; 578 } 579 else 580 { 581 best_on_point_first = -1; 582 best_on_point_last = -1; 583 } 584 585 /* look for the previous and next points on the contour */ 586 /* that are not on the same Y coordinate, then threshold */ 587 /* the `closeness'... */ 588 prev = best_point; 589 next = prev; 590 591 do 592 { 593 if ( prev > best_contour_first ) 594 prev--; 595 else 596 prev = best_contour_last; 597 598 dist = FT_ABS( points[prev].y - best_y ); 599 /* accept a small distance or a small angle (both values are */ 600 /* heuristic; value 20 corresponds to approx. 2.9 degrees) */ 601 if ( dist > 5 ) 602 if ( FT_ABS( points[prev].x - best_x ) <= 20 * dist ) 603 break; 604 605 best_segment_first = prev; 606 607 if ( FT_CURVE_TAG( outline.tags[prev] ) == FT_CURVE_TAG_ON ) 608 { 609 best_on_point_first = prev; 610 if ( best_on_point_last < 0 ) 611 best_on_point_last = prev; 612 } 613 614 } while ( prev != best_point ); 615 616 do 617 { 618 if ( next < best_contour_last ) 619 next++; 620 else 621 next = best_contour_first; 622 623 dist = FT_ABS( points[next].y - best_y ); 624 if ( dist > 5 ) 625 if ( FT_ABS( points[next].x - best_x ) <= 20 * dist ) 626 break; 627 628 best_segment_last = next; 629 630 if ( FT_CURVE_TAG( outline.tags[next] ) == FT_CURVE_TAG_ON ) 631 { 632 best_on_point_last = next; 633 if ( best_on_point_first < 0 ) 634 best_on_point_first = next; 635 } 636 637 } while ( next != best_point ); 638 639 if ( AF_LATIN_IS_LONG_BLUE( bs ) ) 640 { 641 /* If this flag is set, we have an additional constraint to */ 642 /* get the blue zone distance: Find a segment of the topmost */ 643 /* (or bottommost) contour that is longer than a heuristic */ 644 /* threshold. This ensures that small bumps in the outline */ 645 /* are ignored (for example, the `vertical serifs' found in */ 646 /* many Hebrew glyph designs). */ 647 648 /* If this segment is long enough, we are done. Otherwise, */ 649 /* search the segment next to the extremum that is long */ 650 /* enough, has the same direction, and a not too large */ 651 /* vertical distance from the extremum. Note that the */ 652 /* algorithm doesn't check whether the found segment is */ 653 /* actually the one (vertically) nearest to the extremum. */ 654 655 /* heuristic threshold value */ 656 FT_Pos length_threshold = metrics->units_per_em / 25; 657 658 659 dist = FT_ABS( points[best_segment_last].x - 660 points[best_segment_first].x ); 661 662 if ( dist < length_threshold && 663 best_segment_last - best_segment_first + 2 <= 664 best_contour_last - best_contour_first ) 665 { 666 /* heuristic threshold value */ 667 FT_Pos height_threshold = metrics->units_per_em / 4; 668 669 FT_Int first; 670 FT_Int last; 671 FT_Bool hit; 672 673 /* we intentionally declare these two variables */ 674 /* outside of the loop since various compilers emit */ 675 /* incorrect warning messages otherwise, talking about */ 676 /* `possibly uninitialized variables' */ 677 FT_Int p_first = 0; /* make compiler happy */ 678 FT_Int p_last = 0; 679 680 FT_Bool left2right; 681 682 683 /* compute direction */ 684 prev = best_point; 685 686 do 687 { 688 if ( prev > best_contour_first ) 689 prev--; 690 else 691 prev = best_contour_last; 692 693 if ( points[prev].x != best_x ) 694 break; 695 696 } while ( prev != best_point ); 697 698 /* skip glyph for the degenerate case */ 699 if ( prev == best_point ) 700 continue; 701 702 left2right = FT_BOOL( points[prev].x < points[best_point].x ); 703 704 first = best_segment_last; 705 last = first; 706 hit = 0; 707 708 do 709 { 710 FT_Bool l2r; 711 FT_Pos d; 712 713 714 if ( !hit ) 715 { 716 /* no hit; adjust first point */ 717 first = last; 718 719 /* also adjust first and last on point */ 720 if ( FT_CURVE_TAG( outline.tags[first] ) == 721 FT_CURVE_TAG_ON ) 722 { 723 p_first = first; 724 p_last = first; 725 } 726 else 727 { 728 p_first = -1; 729 p_last = -1; 730 } 731 732 hit = 1; 733 } 734 735 if ( last < best_contour_last ) 736 last++; 737 else 738 last = best_contour_first; 739 740 if ( FT_ABS( best_y - points[first].y ) > height_threshold ) 741 { 742 /* vertical distance too large */ 743 hit = 0; 744 continue; 745 } 746 747 /* same test as above */ 748 dist = FT_ABS( points[last].y - points[first].y ); 749 if ( dist > 5 ) 750 if ( FT_ABS( points[last].x - points[first].x ) <= 751 20 * dist ) 752 { 753 hit = 0; 754 continue; 755 } 756 757 if ( FT_CURVE_TAG( outline.tags[last] ) == FT_CURVE_TAG_ON ) 758 { 759 p_last = last; 760 if ( p_first < 0 ) 761 p_first = last; 762 } 763 764 l2r = FT_BOOL( points[first].x < points[last].x ); 765 d = FT_ABS( points[last].x - points[first].x ); 766 767 if ( l2r == left2right && 768 d >= length_threshold ) 769 { 770 /* all constraints are met; update segment after */ 771 /* finding its end */ 772 do 773 { 774 if ( last < best_contour_last ) 775 last++; 776 else 777 last = best_contour_first; 778 779 d = FT_ABS( points[last].y - points[first].y ); 780 if ( d > 5 ) 781 if ( FT_ABS( points[next].x - points[first].x ) <= 782 20 * dist ) 783 { 784 if ( last > best_contour_first ) 785 last--; 786 else 787 last = best_contour_last; 788 break; 789 } 790 791 p_last = last; 792 793 if ( FT_CURVE_TAG( outline.tags[last] ) == 794 FT_CURVE_TAG_ON ) 795 { 796 p_last = last; 797 if ( p_first < 0 ) 798 p_first = last; 799 } 800 801 } while ( last != best_segment_first ); 802 803 best_y = points[first].y; 804 805 best_segment_first = first; 806 best_segment_last = last; 807 808 best_on_point_first = p_first; 809 best_on_point_last = p_last; 810 811 break; 812 } 813 814 } while ( last != best_segment_first ); 815 } 816 } 817 818 /* for computing blue zones, we add the y offset as returned */ 819 /* by the currently used OpenType feature -- for example, */ 820 /* superscript glyphs might be identical to subscript glyphs */ 821 /* with a vertical shift */ 822 best_y += y_offset; 823 824 #ifdef FT_DEBUG_LEVEL_TRACE 825 if ( num_idx == 1 ) 826 FT_TRACE5(( " U+%04lX: best_y = %5ld", ch, best_y )); 827 else 828 FT_TRACE5(( " component %d of cluster starting with U+%04lX:" 829 " best_y = %5ld", i, ch, best_y )); 830 #endif 831 832 /* now set the `round' flag depending on the segment's kind: */ 833 /* */ 834 /* - if the horizontal distance between the first and last */ 835 /* `on' point is larger than a heuristic threshold */ 836 /* we have a flat segment */ 837 /* - if either the first or the last point of the segment is */ 838 /* an `off' point, the segment is round, otherwise it is */ 839 /* flat */ 840 if ( best_on_point_first >= 0 && 841 best_on_point_last >= 0 && 842 ( FT_ABS( points[best_on_point_last].x - 843 points[best_on_point_first].x ) ) > 844 flat_threshold ) 845 round = 0; 846 else 847 round = FT_BOOL( 848 FT_CURVE_TAG( outline.tags[best_segment_first] ) != 849 FT_CURVE_TAG_ON || 850 FT_CURVE_TAG( outline.tags[best_segment_last] ) != 851 FT_CURVE_TAG_ON ); 852 853 if ( round && AF_LATIN_IS_NEUTRAL_BLUE( bs ) ) 854 { 855 /* only use flat segments for a neutral blue zone */ 856 FT_TRACE5(( " (round, skipped)\n" )); 857 continue; 858 } 859 860 FT_TRACE5(( " (%s)\n", round ? "round" : "flat" )); 861 } 862 863 if ( AF_LATIN_IS_TOP_BLUE( bs ) ) 864 { 865 if ( best_y > best_y_extremum ) 866 { 867 best_y_extremum = best_y; 868 best_round = round; 869 } 870 } 871 else 872 { 873 if ( best_y < best_y_extremum ) 874 { 875 best_y_extremum = best_y; 876 best_round = round; 877 } 878 } 879 880 } /* end for loop */ 881 882 if ( !( best_y_extremum == FT_INT_MIN || 883 best_y_extremum == FT_INT_MAX ) ) 884 { 885 if ( best_round ) 886 rounds[num_rounds++] = best_y_extremum; 887 else 888 flats[num_flats++] = best_y_extremum; 889 } 890 891 } /* end while loop */ 892 893 if ( num_flats == 0 && num_rounds == 0 ) 894 { 895 /* 896 * we couldn't find a single glyph to compute this blue zone, 897 * we will simply ignore it then 898 */ 899 FT_TRACE5(( " empty\n" )); 900 continue; 901 } 902 903 /* we have computed the contents of the `rounds' and `flats' tables, */ 904 /* now determine the reference and overshoot position of the blue -- */ 905 /* we simply take the median value after a simple sort */ 906 af_sort_pos( num_rounds, rounds ); 907 af_sort_pos( num_flats, flats ); 908 909 blue = &axis->blues[axis->blue_count]; 910 blue_ref = &blue->ref.org; 911 blue_shoot = &blue->shoot.org; 912 913 axis->blue_count++; 914 915 if ( num_flats == 0 ) 916 { 917 *blue_ref = 918 *blue_shoot = rounds[num_rounds / 2]; 919 } 920 else if ( num_rounds == 0 ) 921 { 922 *blue_ref = 923 *blue_shoot = flats[num_flats / 2]; 924 } 925 else 926 { 927 *blue_ref = flats [num_flats / 2]; 928 *blue_shoot = rounds[num_rounds / 2]; 929 } 930 931 /* there are sometimes problems: if the overshoot position of top */ 932 /* zones is under its reference position, or the opposite for bottom */ 933 /* zones. We must thus check everything there and correct the errors */ 934 if ( *blue_shoot != *blue_ref ) 935 { 936 FT_Pos ref = *blue_ref; 937 FT_Pos shoot = *blue_shoot; 938 FT_Bool over_ref = FT_BOOL( shoot > ref ); 939 940 941 if ( ( AF_LATIN_IS_TOP_BLUE( bs ) || 942 AF_LATIN_IS_SUB_TOP_BLUE( bs) ) ^ over_ref ) 943 { 944 *blue_ref = 945 *blue_shoot = ( shoot + ref ) / 2; 946 947 FT_TRACE5(( " [overshoot smaller than reference," 948 " taking mean value]\n" )); 949 } 950 } 951 952 blue->ascender = ascender; 953 blue->descender = descender; 954 955 blue->flags = 0; 956 if ( AF_LATIN_IS_TOP_BLUE( bs ) ) 957 blue->flags |= AF_LATIN_BLUE_TOP; 958 if ( AF_LATIN_IS_SUB_TOP_BLUE( bs ) ) 959 blue->flags |= AF_LATIN_BLUE_SUB_TOP; 960 if ( AF_LATIN_IS_NEUTRAL_BLUE( bs ) ) 961 blue->flags |= AF_LATIN_BLUE_NEUTRAL; 962 963 /* 964 * The following flag is used later to adjust the y and x scales 965 * in order to optimize the pixel grid alignment of the top of small 966 * letters. 967 */ 968 if ( AF_LATIN_IS_X_HEIGHT_BLUE( bs ) ) 969 blue->flags |= AF_LATIN_BLUE_ADJUSTMENT; 970 971 FT_TRACE5(( " -> reference = %ld\n", *blue_ref )); 972 FT_TRACE5(( " overshoot = %ld\n", *blue_shoot )); 973 974 } /* end for loop */ 975 976 af_shaper_buf_destroy( face, shaper_buf ); 977 978 if ( axis->blue_count ) 979 { 980 /* we finally check whether blue zones are ordered; */ 981 /* `ref' and `shoot' values of two blue zones must not overlap */ 982 983 FT_UInt i; 984 AF_LatinBlue blue_sorted[AF_BLUE_STRINGSET_MAX_LEN + 2]; 985 986 987 for ( i = 0; i < axis->blue_count; i++ ) 988 blue_sorted[i] = &axis->blues[i]; 989 990 /* sort bottoms of blue zones... */ 991 af_latin_sort_blue( axis->blue_count, blue_sorted ); 992 993 /* ...and adjust top values if necessary */ 994 for ( i = 0; i < axis->blue_count - 1; i++ ) 995 { 996 FT_Pos* a; 997 FT_Pos* b; 998 999 #ifdef FT_DEBUG_LEVEL_TRACE 1000 FT_Bool a_is_top = 0; 1001 #endif 1002 1003 1004 if ( blue_sorted[i]->flags & ( AF_LATIN_BLUE_TOP | 1005 AF_LATIN_BLUE_SUB_TOP ) ) 1006 { 1007 a = &blue_sorted[i]->shoot.org; 1008 #ifdef FT_DEBUG_LEVEL_TRACE 1009 a_is_top = 1; 1010 #endif 1011 } 1012 else 1013 a = &blue_sorted[i]->ref.org; 1014 1015 if ( blue_sorted[i + 1]->flags & ( AF_LATIN_BLUE_TOP | 1016 AF_LATIN_BLUE_SUB_TOP ) ) 1017 b = &blue_sorted[i + 1]->shoot.org; 1018 else 1019 b = &blue_sorted[i + 1]->ref.org; 1020 1021 if ( *a > *b ) 1022 { 1023 *a = *b; 1024 FT_TRACE5(( "blue zone overlap:" 1025 " adjusting %s %td to %ld\n", 1026 a_is_top ? "overshoot" : "reference", 1027 blue_sorted[i] - axis->blues, 1028 *a )); 1029 } 1030 } 1031 1032 FT_TRACE5(( "\n" )); 1033 1034 return 0; 1035 } 1036 else 1037 { 1038 /* disable hinting for the current style if there are no blue zones */ 1039 1040 AF_FaceGlobals globals = metrics->root.globals; 1041 FT_UShort* gstyles = globals->glyph_styles; 1042 1043 FT_UInt i; 1044 1045 1046 FT_TRACE5(( "no blue zones found:" 1047 " hinting disabled for this style\n" )); 1048 1049 for ( i = 0; i < globals->glyph_count; i++ ) 1050 { 1051 if ( ( gstyles[i] & AF_STYLE_MASK ) == sc->style ) 1052 gstyles[i] = AF_STYLE_NONE_DFLT; 1053 } 1054 1055 FT_TRACE5(( "\n" )); 1056 1057 return 1; 1058 } 1059 } 1060 1061 1062 /* Check whether all ASCII digits have the same advance width. */ 1063 1064 FT_LOCAL_DEF( void ) af_latin_metrics_check_digits(AF_LatinMetrics metrics,FT_Face face)1065 af_latin_metrics_check_digits( AF_LatinMetrics metrics, 1066 FT_Face face ) 1067 { 1068 FT_Bool started = 0, same_width = 1; 1069 FT_Long advance = 0, old_advance = 0; 1070 1071 /* If HarfBuzz is not available, we need a pointer to a single */ 1072 /* unsigned long value. */ 1073 #ifdef FT_CONFIG_OPTION_USE_HARFBUZZ 1074 void* shaper_buf; 1075 #else 1076 FT_ULong shaper_buf_; 1077 void* shaper_buf = &shaper_buf_; 1078 #endif 1079 1080 /* in all supported charmaps, digits have character codes 0x30-0x39 */ 1081 const char digits[] = "0 1 2 3 4 5 6 7 8 9"; 1082 const char* p; 1083 1084 1085 p = digits; 1086 1087 #ifdef FT_CONFIG_OPTION_USE_HARFBUZZ 1088 shaper_buf = af_shaper_buf_create( face ); 1089 #endif 1090 1091 while ( *p ) 1092 { 1093 FT_ULong glyph_index; 1094 unsigned int num_idx; 1095 1096 1097 /* reject input that maps to more than a single glyph */ 1098 p = af_shaper_get_cluster( p, &metrics->root, shaper_buf, &num_idx ); 1099 if ( num_idx > 1 ) 1100 continue; 1101 1102 glyph_index = af_shaper_get_elem( &metrics->root, 1103 shaper_buf, 1104 0, 1105 &advance, 1106 NULL ); 1107 if ( !glyph_index ) 1108 continue; 1109 1110 if ( started ) 1111 { 1112 if ( advance != old_advance ) 1113 { 1114 same_width = 0; 1115 break; 1116 } 1117 } 1118 else 1119 { 1120 old_advance = advance; 1121 started = 1; 1122 } 1123 } 1124 1125 af_shaper_buf_destroy( face, shaper_buf ); 1126 1127 metrics->root.digits_have_same_width = same_width; 1128 } 1129 1130 1131 /* Initialize global metrics. */ 1132 1133 FT_LOCAL_DEF( FT_Error ) af_latin_metrics_init(AF_StyleMetrics metrics_,FT_Face face)1134 af_latin_metrics_init( AF_StyleMetrics metrics_, /* AF_LatinMetrics */ 1135 FT_Face face ) 1136 { 1137 AF_LatinMetrics metrics = (AF_LatinMetrics)metrics_; 1138 1139 FT_Error error = FT_Err_Ok; 1140 1141 FT_CharMap oldmap = face->charmap; 1142 1143 1144 metrics->units_per_em = face->units_per_EM; 1145 1146 if ( !FT_Select_Charmap( face, FT_ENCODING_UNICODE ) ) 1147 { 1148 af_latin_metrics_init_widths( metrics, face ); 1149 if ( af_latin_metrics_init_blues( metrics, face ) ) 1150 { 1151 /* use internal error code to indicate missing blue zones */ 1152 error = -1; 1153 goto Exit; 1154 } 1155 af_latin_metrics_check_digits( metrics, face ); 1156 } 1157 1158 Exit: 1159 face->charmap = oldmap; 1160 return error; 1161 } 1162 1163 1164 /* Adjust scaling value, then scale and shift widths */ 1165 /* and blue zones (if applicable) for given dimension. */ 1166 1167 static void af_latin_metrics_scale_dim(AF_LatinMetrics metrics,AF_Scaler scaler,AF_Dimension dim)1168 af_latin_metrics_scale_dim( AF_LatinMetrics metrics, 1169 AF_Scaler scaler, 1170 AF_Dimension dim ) 1171 { 1172 FT_Fixed scale; 1173 FT_Pos delta; 1174 AF_LatinAxis axis; 1175 FT_UInt nn; 1176 1177 1178 if ( dim == AF_DIMENSION_HORZ ) 1179 { 1180 scale = scaler->x_scale; 1181 delta = scaler->x_delta; 1182 } 1183 else 1184 { 1185 scale = scaler->y_scale; 1186 delta = scaler->y_delta; 1187 } 1188 1189 axis = &metrics->axis[dim]; 1190 1191 if ( axis->org_scale == scale && axis->org_delta == delta ) 1192 return; 1193 1194 axis->org_scale = scale; 1195 axis->org_delta = delta; 1196 1197 /* 1198 * correct X and Y scale to optimize the alignment of the top of small 1199 * letters to the pixel grid 1200 */ 1201 { 1202 AF_LatinAxis Axis = &metrics->axis[AF_DIMENSION_VERT]; 1203 AF_LatinBlue blue = NULL; 1204 1205 1206 for ( nn = 0; nn < Axis->blue_count; nn++ ) 1207 { 1208 if ( Axis->blues[nn].flags & AF_LATIN_BLUE_ADJUSTMENT ) 1209 { 1210 blue = &Axis->blues[nn]; 1211 break; 1212 } 1213 } 1214 1215 if ( blue ) 1216 { 1217 FT_Pos scaled; 1218 FT_Pos threshold; 1219 FT_Pos fitted; 1220 FT_UInt limit; 1221 FT_UInt ppem; 1222 1223 1224 scaled = FT_MulFix( blue->shoot.org, scale ); 1225 ppem = metrics->root.scaler.face->size->metrics.x_ppem; 1226 limit = metrics->root.globals->increase_x_height; 1227 threshold = 40; 1228 1229 /* if the `increase-x-height' property is active, */ 1230 /* we round up much more often */ 1231 if ( limit && 1232 ppem <= limit && 1233 ppem >= AF_PROP_INCREASE_X_HEIGHT_MIN ) 1234 threshold = 52; 1235 1236 fitted = ( scaled + threshold ) & ~63; 1237 1238 if ( scaled != fitted ) 1239 { 1240 #if 0 1241 if ( dim == AF_DIMENSION_HORZ ) 1242 { 1243 if ( fitted < scaled ) 1244 scale -= scale / 50; /* scale *= 0.98 */ 1245 } 1246 else 1247 #endif 1248 if ( dim == AF_DIMENSION_VERT ) 1249 { 1250 FT_Pos max_height; 1251 FT_Pos dist; 1252 FT_Fixed new_scale; 1253 1254 1255 new_scale = FT_MulDiv( scale, fitted, scaled ); 1256 1257 /* the scaling should not change the result by more than two pixels */ 1258 max_height = metrics->units_per_em; 1259 1260 for ( nn = 0; nn < Axis->blue_count; nn++ ) 1261 { 1262 max_height = FT_MAX( max_height, Axis->blues[nn].ascender ); 1263 max_height = FT_MAX( max_height, -Axis->blues[nn].descender ); 1264 } 1265 1266 dist = FT_ABS( FT_MulFix( max_height, new_scale - scale ) ); 1267 dist &= ~127; 1268 1269 if ( dist == 0 ) 1270 { 1271 FT_TRACE5(( "af_latin_metrics_scale_dim:" 1272 " x height alignment (style `%s'):\n", 1273 af_style_names[metrics->root.style_class->style] )); 1274 FT_TRACE5(( " " 1275 " vertical scaling changed" 1276 " from %.5f to %.5f (by %ld%%)\n", 1277 (double)scale / 65536, 1278 (double)new_scale / 65536, 1279 ( fitted - scaled ) * 100 / scaled )); 1280 FT_TRACE5(( "\n" )); 1281 1282 scale = new_scale; 1283 } 1284 #ifdef FT_DEBUG_LEVEL_TRACE 1285 else 1286 { 1287 FT_TRACE5(( "af_latin_metrics_scale_dim:" 1288 " x height alignment (style `%s'):\n", 1289 af_style_names[metrics->root.style_class->style] )); 1290 FT_TRACE5(( " " 1291 " excessive vertical scaling abandoned\n" )); 1292 FT_TRACE5(( "\n" )); 1293 } 1294 #endif 1295 } 1296 } 1297 } 1298 } 1299 1300 axis->scale = scale; 1301 axis->delta = delta; 1302 1303 if ( dim == AF_DIMENSION_HORZ ) 1304 { 1305 metrics->root.scaler.x_scale = scale; 1306 metrics->root.scaler.x_delta = delta; 1307 } 1308 else 1309 { 1310 metrics->root.scaler.y_scale = scale; 1311 metrics->root.scaler.y_delta = delta; 1312 } 1313 1314 FT_TRACE5(( "%s widths (style `%s')\n", 1315 dim == AF_DIMENSION_HORZ ? "horizontal" : "vertical", 1316 af_style_names[metrics->root.style_class->style] )); 1317 1318 /* scale the widths */ 1319 for ( nn = 0; nn < axis->width_count; nn++ ) 1320 { 1321 AF_Width width = axis->widths + nn; 1322 1323 1324 width->cur = FT_MulFix( width->org, scale ); 1325 width->fit = width->cur; 1326 1327 FT_TRACE5(( " %ld scaled to %.2f\n", 1328 width->org, 1329 (double)width->cur / 64 )); 1330 } 1331 1332 FT_TRACE5(( "\n" )); 1333 1334 /* an extra-light axis corresponds to a standard width that is */ 1335 /* smaller than 5/8 pixels */ 1336 axis->extra_light = 1337 FT_BOOL( FT_MulFix( axis->standard_width, scale ) < 32 + 8 ); 1338 1339 #ifdef FT_DEBUG_LEVEL_TRACE 1340 if ( axis->extra_light ) 1341 { 1342 FT_TRACE5(( "`%s' style is extra light (at current resolution)\n", 1343 af_style_names[metrics->root.style_class->style] )); 1344 FT_TRACE5(( "\n" )); 1345 } 1346 #endif 1347 1348 if ( dim == AF_DIMENSION_VERT ) 1349 { 1350 #ifdef FT_DEBUG_LEVEL_TRACE 1351 if ( axis->blue_count ) 1352 FT_TRACE5(( "blue zones (style `%s')\n", 1353 af_style_names[metrics->root.style_class->style] )); 1354 #endif 1355 1356 /* scale the blue zones */ 1357 for ( nn = 0; nn < axis->blue_count; nn++ ) 1358 { 1359 AF_LatinBlue blue = &axis->blues[nn]; 1360 FT_Pos dist; 1361 1362 1363 blue->ref.cur = FT_MulFix( blue->ref.org, scale ) + delta; 1364 blue->ref.fit = blue->ref.cur; 1365 blue->shoot.cur = FT_MulFix( blue->shoot.org, scale ) + delta; 1366 blue->shoot.fit = blue->shoot.cur; 1367 blue->flags &= ~AF_LATIN_BLUE_ACTIVE; 1368 1369 /* a blue zone is only active if it is less than 3/4 pixels tall */ 1370 dist = FT_MulFix( blue->ref.org - blue->shoot.org, scale ); 1371 if ( dist <= 48 && dist >= -48 ) 1372 { 1373 #if 0 1374 FT_Pos delta1; 1375 #endif 1376 FT_Pos delta2; 1377 1378 1379 /* use discrete values for blue zone widths */ 1380 1381 #if 0 1382 1383 /* generic, original code */ 1384 delta1 = blue->shoot.org - blue->ref.org; 1385 delta2 = delta1; 1386 if ( delta1 < 0 ) 1387 delta2 = -delta2; 1388 1389 delta2 = FT_MulFix( delta2, scale ); 1390 1391 if ( delta2 < 32 ) 1392 delta2 = 0; 1393 else if ( delta2 < 64 ) 1394 delta2 = 32 + ( ( ( delta2 - 32 ) + 16 ) & ~31 ); 1395 else 1396 delta2 = FT_PIX_ROUND( delta2 ); 1397 1398 if ( delta1 < 0 ) 1399 delta2 = -delta2; 1400 1401 blue->ref.fit = FT_PIX_ROUND( blue->ref.cur ); 1402 blue->shoot.fit = blue->ref.fit + delta2; 1403 1404 #else 1405 1406 /* simplified version due to abs(dist) <= 48 */ 1407 delta2 = dist; 1408 if ( dist < 0 ) 1409 delta2 = -delta2; 1410 1411 if ( delta2 < 32 ) 1412 delta2 = 0; 1413 else if ( delta2 < 48 ) 1414 delta2 = 32; 1415 else 1416 delta2 = 64; 1417 1418 if ( dist < 0 ) 1419 delta2 = -delta2; 1420 1421 blue->ref.fit = FT_PIX_ROUND( blue->ref.cur ); 1422 blue->shoot.fit = blue->ref.fit - delta2; 1423 1424 #endif 1425 1426 blue->flags |= AF_LATIN_BLUE_ACTIVE; 1427 } 1428 } 1429 1430 /* use sub-top blue zone only if it doesn't overlap with */ 1431 /* another (non-sup-top) blue zone; otherwise, the */ 1432 /* effect would be similar to a neutral blue zone, which */ 1433 /* is not desired here */ 1434 for ( nn = 0; nn < axis->blue_count; nn++ ) 1435 { 1436 AF_LatinBlue blue = &axis->blues[nn]; 1437 FT_UInt i; 1438 1439 1440 if ( !( blue->flags & AF_LATIN_BLUE_SUB_TOP ) ) 1441 continue; 1442 if ( !( blue->flags & AF_LATIN_BLUE_ACTIVE ) ) 1443 continue; 1444 1445 for ( i = 0; i < axis->blue_count; i++ ) 1446 { 1447 AF_LatinBlue b = &axis->blues[i]; 1448 1449 1450 if ( b->flags & AF_LATIN_BLUE_SUB_TOP ) 1451 continue; 1452 if ( !( b->flags & AF_LATIN_BLUE_ACTIVE ) ) 1453 continue; 1454 1455 if ( b->ref.fit <= blue->shoot.fit && 1456 b->shoot.fit >= blue->ref.fit ) 1457 { 1458 blue->flags &= ~AF_LATIN_BLUE_ACTIVE; 1459 break; 1460 } 1461 } 1462 } 1463 1464 #ifdef FT_DEBUG_LEVEL_TRACE 1465 for ( nn = 0; nn < axis->blue_count; nn++ ) 1466 { 1467 AF_LatinBlue blue = &axis->blues[nn]; 1468 1469 1470 FT_TRACE5(( " reference %d: %ld scaled to %.2f%s\n", 1471 nn, 1472 blue->ref.org, 1473 (double)blue->ref.fit / 64, 1474 ( blue->flags & AF_LATIN_BLUE_ACTIVE ) ? "" 1475 : " (inactive)" )); 1476 FT_TRACE5(( " overshoot %d: %ld scaled to %.2f%s\n", 1477 nn, 1478 blue->shoot.org, 1479 (double)blue->shoot.fit / 64, 1480 ( blue->flags & AF_LATIN_BLUE_ACTIVE ) ? "" 1481 : " (inactive)" )); 1482 } 1483 #endif 1484 } 1485 } 1486 1487 1488 /* Scale global values in both directions. */ 1489 1490 FT_LOCAL_DEF( void ) af_latin_metrics_scale(AF_StyleMetrics metrics_,AF_Scaler scaler)1491 af_latin_metrics_scale( AF_StyleMetrics metrics_, /* AF_LatinMetrics */ 1492 AF_Scaler scaler ) 1493 { 1494 AF_LatinMetrics metrics = (AF_LatinMetrics)metrics_; 1495 1496 1497 metrics->root.scaler.render_mode = scaler->render_mode; 1498 metrics->root.scaler.face = scaler->face; 1499 metrics->root.scaler.flags = scaler->flags; 1500 1501 af_latin_metrics_scale_dim( metrics, scaler, AF_DIMENSION_HORZ ); 1502 af_latin_metrics_scale_dim( metrics, scaler, AF_DIMENSION_VERT ); 1503 } 1504 1505 1506 /* Extract standard_width from writing system/script specific */ 1507 /* metrics class. */ 1508 1509 FT_CALLBACK_DEF( void ) af_latin_get_standard_widths(AF_StyleMetrics metrics_,FT_Pos * stdHW,FT_Pos * stdVW)1510 af_latin_get_standard_widths( AF_StyleMetrics metrics_, /* AF_LatinMetrics */ 1511 FT_Pos* stdHW, 1512 FT_Pos* stdVW ) 1513 { 1514 AF_LatinMetrics metrics = (AF_LatinMetrics)metrics_; 1515 1516 1517 if ( stdHW ) 1518 *stdHW = metrics->axis[AF_DIMENSION_VERT].standard_width; 1519 1520 if ( stdVW ) 1521 *stdVW = metrics->axis[AF_DIMENSION_HORZ].standard_width; 1522 } 1523 1524 1525 /*************************************************************************/ 1526 /*************************************************************************/ 1527 /***** *****/ 1528 /***** L A T I N G L Y P H A N A L Y S I S *****/ 1529 /***** *****/ 1530 /*************************************************************************/ 1531 /*************************************************************************/ 1532 1533 1534 /* Walk over all contours and compute its segments. */ 1535 1536 FT_LOCAL_DEF( FT_Error ) af_latin_hints_compute_segments(AF_GlyphHints hints,AF_Dimension dim)1537 af_latin_hints_compute_segments( AF_GlyphHints hints, 1538 AF_Dimension dim ) 1539 { 1540 AF_LatinMetrics metrics = (AF_LatinMetrics)hints->metrics; 1541 AF_AxisHints axis = &hints->axis[dim]; 1542 FT_Memory memory = hints->memory; 1543 FT_Error error = FT_Err_Ok; 1544 AF_Segment segment = NULL; 1545 AF_SegmentRec seg0; 1546 AF_Point* contour = hints->contours; 1547 AF_Point* contour_limit = contour + hints->num_contours; 1548 AF_Direction major_dir, segment_dir; 1549 1550 FT_Pos flat_threshold = FLAT_THRESHOLD( metrics->units_per_em ); 1551 1552 1553 FT_ZERO( &seg0 ); 1554 seg0.score = 32000; 1555 seg0.flags = AF_EDGE_NORMAL; 1556 1557 major_dir = (AF_Direction)FT_ABS( axis->major_dir ); 1558 segment_dir = major_dir; 1559 1560 axis->num_segments = 0; 1561 1562 /* set up (u,v) in each point */ 1563 if ( dim == AF_DIMENSION_HORZ ) 1564 { 1565 AF_Point point = hints->points; 1566 AF_Point limit = point + hints->num_points; 1567 1568 1569 for ( ; point < limit; point++ ) 1570 { 1571 point->u = point->fx; 1572 point->v = point->fy; 1573 } 1574 } 1575 else 1576 { 1577 AF_Point point = hints->points; 1578 AF_Point limit = point + hints->num_points; 1579 1580 1581 for ( ; point < limit; point++ ) 1582 { 1583 point->u = point->fy; 1584 point->v = point->fx; 1585 } 1586 } 1587 1588 /* do each contour separately */ 1589 for ( ; contour < contour_limit; contour++ ) 1590 { 1591 AF_Point point = contour[0]; 1592 AF_Point last = point->prev; 1593 int on_edge = 0; 1594 1595 /* we call values measured along a segment (point->v) */ 1596 /* `coordinates', and values orthogonal to it (point->u) */ 1597 /* `positions' */ 1598 FT_Pos min_pos = 32000; 1599 FT_Pos max_pos = -32000; 1600 FT_Pos min_coord = 32000; 1601 FT_Pos max_coord = -32000; 1602 FT_UShort min_flags = AF_FLAG_NONE; 1603 FT_UShort max_flags = AF_FLAG_NONE; 1604 FT_Pos min_on_coord = 32000; 1605 FT_Pos max_on_coord = -32000; 1606 1607 FT_Bool passed; 1608 1609 AF_Segment prev_segment = NULL; 1610 1611 FT_Pos prev_min_pos = min_pos; 1612 FT_Pos prev_max_pos = max_pos; 1613 FT_Pos prev_min_coord = min_coord; 1614 FT_Pos prev_max_coord = max_coord; 1615 FT_UShort prev_min_flags = min_flags; 1616 FT_UShort prev_max_flags = max_flags; 1617 FT_Pos prev_min_on_coord = min_on_coord; 1618 FT_Pos prev_max_on_coord = max_on_coord; 1619 1620 1621 if ( FT_ABS( last->out_dir ) == major_dir && 1622 FT_ABS( point->out_dir ) == major_dir ) 1623 { 1624 /* we are already on an edge, try to locate its start */ 1625 last = point; 1626 1627 for (;;) 1628 { 1629 point = point->prev; 1630 if ( FT_ABS( point->out_dir ) != major_dir ) 1631 { 1632 point = point->next; 1633 break; 1634 } 1635 if ( point == last ) 1636 break; 1637 } 1638 } 1639 1640 last = point; 1641 passed = 0; 1642 1643 for (;;) 1644 { 1645 FT_Pos u, v; 1646 1647 1648 if ( on_edge ) 1649 { 1650 /* get minimum and maximum position */ 1651 u = point->u; 1652 if ( u < min_pos ) 1653 min_pos = u; 1654 if ( u > max_pos ) 1655 max_pos = u; 1656 1657 /* get minimum and maximum coordinate together with flags */ 1658 v = point->v; 1659 if ( v < min_coord ) 1660 { 1661 min_coord = v; 1662 min_flags = point->flags; 1663 } 1664 if ( v > max_coord ) 1665 { 1666 max_coord = v; 1667 max_flags = point->flags; 1668 } 1669 1670 /* get minimum and maximum coordinate of `on' points */ 1671 if ( !( point->flags & AF_FLAG_CONTROL ) ) 1672 { 1673 v = point->v; 1674 if ( v < min_on_coord ) 1675 min_on_coord = v; 1676 if ( v > max_on_coord ) 1677 max_on_coord = v; 1678 } 1679 1680 if ( point->out_dir != segment_dir || point == last ) 1681 { 1682 /* check whether the new segment's start point is identical to */ 1683 /* the previous segment's end point; for example, this might */ 1684 /* happen for spikes */ 1685 1686 if ( !prev_segment || segment->first != prev_segment->last ) 1687 { 1688 /* points are different: we are just leaving an edge, thus */ 1689 /* record a new segment */ 1690 1691 segment->last = point; 1692 segment->pos = (FT_Short)( ( min_pos + max_pos ) >> 1 ); 1693 segment->delta = (FT_Short)( ( max_pos - min_pos ) >> 1 ); 1694 1695 /* a segment is round if either its first or last point */ 1696 /* is a control point, and the length of the on points */ 1697 /* inbetween doesn't exceed a heuristic limit */ 1698 if ( ( min_flags | max_flags ) & AF_FLAG_CONTROL && 1699 ( max_on_coord - min_on_coord ) < flat_threshold ) 1700 segment->flags |= AF_EDGE_ROUND; 1701 1702 segment->min_coord = (FT_Short)min_coord; 1703 segment->max_coord = (FT_Short)max_coord; 1704 segment->height = segment->max_coord - segment->min_coord; 1705 1706 prev_segment = segment; 1707 prev_min_pos = min_pos; 1708 prev_max_pos = max_pos; 1709 prev_min_coord = min_coord; 1710 prev_max_coord = max_coord; 1711 prev_min_flags = min_flags; 1712 prev_max_flags = max_flags; 1713 prev_min_on_coord = min_on_coord; 1714 prev_max_on_coord = max_on_coord; 1715 } 1716 else 1717 { 1718 /* points are the same: we don't create a new segment but */ 1719 /* merge the current segment with the previous one */ 1720 1721 if ( prev_segment->last->in_dir == point->in_dir ) 1722 { 1723 /* we have identical directions (this can happen for */ 1724 /* degenerate outlines that move zig-zag along the main */ 1725 /* axis without changing the coordinate value of the other */ 1726 /* axis, and where the segments have just been merged): */ 1727 /* unify segments */ 1728 1729 /* update constraints */ 1730 1731 if ( prev_min_pos < min_pos ) 1732 min_pos = prev_min_pos; 1733 if ( prev_max_pos > max_pos ) 1734 max_pos = prev_max_pos; 1735 1736 if ( prev_min_coord < min_coord ) 1737 { 1738 min_coord = prev_min_coord; 1739 min_flags = prev_min_flags; 1740 } 1741 if ( prev_max_coord > max_coord ) 1742 { 1743 max_coord = prev_max_coord; 1744 max_flags = prev_max_flags; 1745 } 1746 1747 if ( prev_min_on_coord < min_on_coord ) 1748 min_on_coord = prev_min_on_coord; 1749 if ( prev_max_on_coord > max_on_coord ) 1750 max_on_coord = prev_max_on_coord; 1751 1752 prev_segment->last = point; 1753 prev_segment->pos = (FT_Short)( ( min_pos + 1754 max_pos ) >> 1 ); 1755 prev_segment->delta = (FT_Short)( ( max_pos - 1756 min_pos ) >> 1 ); 1757 1758 if ( ( min_flags | max_flags ) & AF_FLAG_CONTROL && 1759 ( max_on_coord - min_on_coord ) < flat_threshold ) 1760 prev_segment->flags |= AF_EDGE_ROUND; 1761 else 1762 prev_segment->flags &= ~AF_EDGE_ROUND; 1763 1764 prev_segment->min_coord = (FT_Short)min_coord; 1765 prev_segment->max_coord = (FT_Short)max_coord; 1766 prev_segment->height = prev_segment->max_coord - 1767 prev_segment->min_coord; 1768 } 1769 else 1770 { 1771 /* we have different directions; use the properties of the */ 1772 /* longer segment and discard the other one */ 1773 1774 if ( FT_ABS( prev_max_coord - prev_min_coord ) > 1775 FT_ABS( max_coord - min_coord ) ) 1776 { 1777 /* discard current segment */ 1778 1779 if ( min_pos < prev_min_pos ) 1780 prev_min_pos = min_pos; 1781 if ( max_pos > prev_max_pos ) 1782 prev_max_pos = max_pos; 1783 1784 prev_segment->last = point; 1785 prev_segment->pos = (FT_Short)( ( prev_min_pos + 1786 prev_max_pos ) >> 1 ); 1787 prev_segment->delta = (FT_Short)( ( prev_max_pos - 1788 prev_min_pos ) >> 1 ); 1789 } 1790 else 1791 { 1792 /* discard previous segment */ 1793 1794 if ( prev_min_pos < min_pos ) 1795 min_pos = prev_min_pos; 1796 if ( prev_max_pos > max_pos ) 1797 max_pos = prev_max_pos; 1798 1799 segment->last = point; 1800 segment->pos = (FT_Short)( ( min_pos + max_pos ) >> 1 ); 1801 segment->delta = (FT_Short)( ( max_pos - min_pos ) >> 1 ); 1802 1803 if ( ( min_flags | max_flags ) & AF_FLAG_CONTROL && 1804 ( max_on_coord - min_on_coord ) < flat_threshold ) 1805 segment->flags |= AF_EDGE_ROUND; 1806 1807 segment->min_coord = (FT_Short)min_coord; 1808 segment->max_coord = (FT_Short)max_coord; 1809 segment->height = segment->max_coord - 1810 segment->min_coord; 1811 1812 *prev_segment = *segment; 1813 1814 prev_min_pos = min_pos; 1815 prev_max_pos = max_pos; 1816 prev_min_coord = min_coord; 1817 prev_max_coord = max_coord; 1818 prev_min_flags = min_flags; 1819 prev_max_flags = max_flags; 1820 prev_min_on_coord = min_on_coord; 1821 prev_max_on_coord = max_on_coord; 1822 } 1823 } 1824 1825 axis->num_segments--; 1826 } 1827 1828 on_edge = 0; 1829 segment = NULL; 1830 1831 /* fall through */ 1832 } 1833 } 1834 1835 /* now exit if we are at the start/end point */ 1836 if ( point == last ) 1837 { 1838 if ( passed ) 1839 break; 1840 passed = 1; 1841 } 1842 1843 /* if we are not on an edge, check whether the major direction */ 1844 /* coincides with the current point's `out' direction, or */ 1845 /* whether we have a single-point contour */ 1846 if ( !on_edge && 1847 ( FT_ABS( point->out_dir ) == major_dir || 1848 point == point->prev ) ) 1849 { 1850 /* 1851 * For efficiency, we restrict the number of segments to 1000, 1852 * which is a heuristic value: it is very unlikely that a glyph 1853 * with so many segments can be hinted in a sensible way. 1854 * Reasons: 1855 * 1856 * - The glyph has really 1000 segments; this implies that it has 1857 * at least 2000 outline points. Assuming 'normal' fonts that 1858 * have superfluous points optimized away, viewing such a glyph 1859 * only makes sense at large magnifications where hinting 1860 * isn't applied anyway. 1861 * 1862 * - We have a broken glyph. Hinting doesn't make sense in this 1863 * case either. 1864 */ 1865 if ( axis->num_segments > 1000 ) 1866 { 1867 FT_TRACE0(( "af_latin_hints_compute_segments:" 1868 " more than 1000 segments in this glyph;\n" )); 1869 FT_TRACE0(( " " 1870 " hinting is suppressed\n" )); 1871 axis->num_segments = 0; 1872 return FT_Err_Ok; 1873 } 1874 1875 /* this is the start of a new segment! */ 1876 segment_dir = (AF_Direction)point->out_dir; 1877 1878 error = af_axis_hints_new_segment( axis, memory, &segment ); 1879 if ( error ) 1880 goto Exit; 1881 1882 /* clear all segment fields */ 1883 segment[0] = seg0; 1884 1885 segment->dir = (FT_Char)segment_dir; 1886 segment->first = point; 1887 segment->last = point; 1888 1889 /* `af_axis_hints_new_segment' reallocates memory, */ 1890 /* thus we have to refresh the `prev_segment' pointer */ 1891 if ( prev_segment ) 1892 prev_segment = segment - 1; 1893 1894 min_pos = max_pos = point->u; 1895 min_coord = max_coord = point->v; 1896 min_flags = max_flags = point->flags; 1897 1898 if ( point->flags & AF_FLAG_CONTROL ) 1899 { 1900 min_on_coord = 32000; 1901 max_on_coord = -32000; 1902 } 1903 else 1904 min_on_coord = max_on_coord = point->v; 1905 1906 on_edge = 1; 1907 1908 if ( point == point->prev ) 1909 { 1910 /* we have a one-point segment: this is a one-point */ 1911 /* contour with `in' and `out' direction set to */ 1912 /* AF_DIR_NONE */ 1913 segment->pos = (FT_Short)min_pos; 1914 1915 if (point->flags & AF_FLAG_CONTROL) 1916 segment->flags |= AF_EDGE_ROUND; 1917 1918 segment->min_coord = (FT_Short)point->v; 1919 segment->max_coord = (FT_Short)point->v; 1920 segment->height = 0; 1921 1922 on_edge = 0; 1923 segment = NULL; 1924 } 1925 } 1926 1927 point = point->next; 1928 } 1929 1930 } /* contours */ 1931 1932 1933 /* now slightly increase the height of segments if this makes */ 1934 /* sense -- this is used to better detect and ignore serifs */ 1935 { 1936 AF_Segment segments = axis->segments; 1937 AF_Segment segments_end = FT_OFFSET( segments, axis->num_segments ); 1938 1939 1940 for ( segment = segments; segment < segments_end; segment++ ) 1941 { 1942 AF_Point first = segment->first; 1943 AF_Point last = segment->last; 1944 FT_Pos first_v = first->v; 1945 FT_Pos last_v = last->v; 1946 1947 1948 if ( first_v < last_v ) 1949 { 1950 AF_Point p; 1951 1952 1953 p = first->prev; 1954 if ( p->v < first_v ) 1955 segment->height = (FT_Short)( segment->height + 1956 ( ( first_v - p->v ) >> 1 ) ); 1957 1958 p = last->next; 1959 if ( p->v > last_v ) 1960 segment->height = (FT_Short)( segment->height + 1961 ( ( p->v - last_v ) >> 1 ) ); 1962 } 1963 else 1964 { 1965 AF_Point p; 1966 1967 1968 p = first->prev; 1969 if ( p->v > first_v ) 1970 segment->height = (FT_Short)( segment->height + 1971 ( ( p->v - first_v ) >> 1 ) ); 1972 1973 p = last->next; 1974 if ( p->v < last_v ) 1975 segment->height = (FT_Short)( segment->height + 1976 ( ( last_v - p->v ) >> 1 ) ); 1977 } 1978 } 1979 } 1980 1981 Exit: 1982 return error; 1983 } 1984 1985 1986 /* Link segments to form stems and serifs. If `width_count' and */ 1987 /* `widths' are non-zero, use them to fine-tune the scoring function. */ 1988 1989 FT_LOCAL_DEF( void ) af_latin_hints_link_segments(AF_GlyphHints hints,FT_UInt width_count,AF_WidthRec * widths,AF_Dimension dim)1990 af_latin_hints_link_segments( AF_GlyphHints hints, 1991 FT_UInt width_count, 1992 AF_WidthRec* widths, 1993 AF_Dimension dim ) 1994 { 1995 AF_AxisHints axis = &hints->axis[dim]; 1996 AF_Segment segments = axis->segments; 1997 AF_Segment segment_limit = FT_OFFSET( segments, axis->num_segments ); 1998 FT_Pos len_threshold, len_score, dist_score, max_width; 1999 AF_Segment seg1, seg2; 2000 2001 2002 if ( width_count ) 2003 max_width = widths[width_count - 1].org; 2004 else 2005 max_width = 0; 2006 2007 /* a heuristic value to set up a minimum value for overlapping */ 2008 len_threshold = AF_LATIN_CONSTANT( hints->metrics, 8 ); 2009 if ( len_threshold == 0 ) 2010 len_threshold = 1; 2011 2012 /* a heuristic value to weight lengths */ 2013 len_score = AF_LATIN_CONSTANT( hints->metrics, 6000 ); 2014 2015 /* a heuristic value to weight distances (no call to */ 2016 /* AF_LATIN_CONSTANT needed, since we work on multiples */ 2017 /* of the stem width) */ 2018 dist_score = 3000; 2019 2020 /* now compare each segment to the others */ 2021 for ( seg1 = segments; seg1 < segment_limit; seg1++ ) 2022 { 2023 if ( seg1->dir != axis->major_dir ) 2024 continue; 2025 2026 /* search for stems having opposite directions, */ 2027 /* with seg1 to the `left' of seg2 */ 2028 for ( seg2 = segments; seg2 < segment_limit; seg2++ ) 2029 { 2030 FT_Pos pos1 = seg1->pos; 2031 FT_Pos pos2 = seg2->pos; 2032 2033 2034 if ( seg1->dir + seg2->dir == 0 && pos2 > pos1 ) 2035 { 2036 /* compute distance between the two segments */ 2037 FT_Pos min = seg1->min_coord; 2038 FT_Pos max = seg1->max_coord; 2039 FT_Pos len; 2040 2041 2042 if ( min < seg2->min_coord ) 2043 min = seg2->min_coord; 2044 2045 if ( max > seg2->max_coord ) 2046 max = seg2->max_coord; 2047 2048 /* compute maximum coordinate difference of the two segments */ 2049 /* (that is, how much they overlap) */ 2050 len = max - min; 2051 if ( len >= len_threshold ) 2052 { 2053 /* 2054 * The score is the sum of two demerits indicating the 2055 * `badness' of a fit, measured along the segments' main axis 2056 * and orthogonal to it, respectively. 2057 * 2058 * - The less overlapping along the main axis, the worse it 2059 * is, causing a larger demerit. 2060 * 2061 * - The nearer the orthogonal distance to a stem width, the 2062 * better it is, causing a smaller demerit. For simplicity, 2063 * however, we only increase the demerit for values that 2064 * exceed the largest stem width. 2065 */ 2066 2067 FT_Pos dist = pos2 - pos1; 2068 2069 FT_Pos dist_demerit, score; 2070 2071 2072 if ( max_width ) 2073 { 2074 /* distance demerits are based on multiples of `max_width'; */ 2075 /* we scale by 1024 for getting more precision */ 2076 FT_Pos delta = ( dist << 10 ) / max_width - ( 1 << 10 ); 2077 2078 2079 if ( delta > 10000 ) 2080 dist_demerit = 32000; 2081 else if ( delta > 0 ) 2082 dist_demerit = delta * delta / dist_score; 2083 else 2084 dist_demerit = 0; 2085 } 2086 else 2087 dist_demerit = dist; /* default if no widths available */ 2088 2089 score = dist_demerit + len_score / len; 2090 2091 /* and we search for the smallest score */ 2092 if ( score < seg1->score ) 2093 { 2094 seg1->score = score; 2095 seg1->link = seg2; 2096 } 2097 2098 if ( score < seg2->score ) 2099 { 2100 seg2->score = score; 2101 seg2->link = seg1; 2102 } 2103 } 2104 } 2105 } 2106 } 2107 2108 /* now compute the `serif' segments, cf. explanations in `afhints.h' */ 2109 for ( seg1 = segments; seg1 < segment_limit; seg1++ ) 2110 { 2111 seg2 = seg1->link; 2112 2113 if ( seg2 ) 2114 { 2115 if ( seg2->link != seg1 ) 2116 { 2117 seg1->link = NULL; 2118 seg1->serif = seg2->link; 2119 } 2120 } 2121 } 2122 } 2123 2124 2125 /* Link segments to edges, using feature analysis for selection. */ 2126 2127 FT_LOCAL_DEF( FT_Error ) af_latin_hints_compute_edges(AF_GlyphHints hints,AF_Dimension dim)2128 af_latin_hints_compute_edges( AF_GlyphHints hints, 2129 AF_Dimension dim ) 2130 { 2131 AF_AxisHints axis = &hints->axis[dim]; 2132 FT_Error error = FT_Err_Ok; 2133 FT_Memory memory = hints->memory; 2134 AF_LatinAxis laxis = &((AF_LatinMetrics)hints->metrics)->axis[dim]; 2135 2136 AF_StyleClass style_class = hints->metrics->style_class; 2137 AF_ScriptClass script_class = af_script_classes[style_class->script]; 2138 2139 FT_Bool top_to_bottom_hinting = 0; 2140 2141 AF_Segment segments = axis->segments; 2142 AF_Segment segment_limit = FT_OFFSET( segments, axis->num_segments ); 2143 AF_Segment seg; 2144 2145 #if 0 2146 AF_Direction up_dir; 2147 #endif 2148 FT_Fixed scale; 2149 FT_Pos edge_distance_threshold; 2150 FT_Pos segment_length_threshold; 2151 FT_Pos segment_width_threshold; 2152 2153 2154 axis->num_edges = 0; 2155 2156 scale = ( dim == AF_DIMENSION_HORZ ) ? hints->x_scale 2157 : hints->y_scale; 2158 2159 #if 0 2160 up_dir = ( dim == AF_DIMENSION_HORZ ) ? AF_DIR_UP 2161 : AF_DIR_RIGHT; 2162 #endif 2163 2164 if ( dim == AF_DIMENSION_VERT ) 2165 top_to_bottom_hinting = script_class->top_to_bottom_hinting; 2166 2167 /* 2168 * We ignore all segments that are less than 1 pixel in length 2169 * to avoid many problems with serif fonts. We compute the 2170 * corresponding threshold in font units. 2171 */ 2172 if ( dim == AF_DIMENSION_HORZ ) 2173 segment_length_threshold = FT_DivFix( 64, hints->y_scale ); 2174 else 2175 segment_length_threshold = 0; 2176 2177 /* 2178 * Similarly, we ignore segments that have a width delta 2179 * larger than 0.5px (i.e., a width larger than 1px). 2180 */ 2181 segment_width_threshold = FT_DivFix( 32, scale ); 2182 2183 /********************************************************************** 2184 * 2185 * We begin by generating a sorted table of edges for the current 2186 * direction. To do so, we simply scan each segment and try to find 2187 * an edge in our table that corresponds to its position. 2188 * 2189 * If no edge is found, we create and insert a new edge in the 2190 * sorted table. Otherwise, we simply add the segment to the edge's 2191 * list which gets processed in the second step to compute the 2192 * edge's properties. 2193 * 2194 * Note that the table of edges is sorted along the segment/edge 2195 * position. 2196 * 2197 */ 2198 2199 /* assure that edge distance threshold is at most 0.25px */ 2200 edge_distance_threshold = FT_MulFix( laxis->edge_distance_threshold, 2201 scale ); 2202 if ( edge_distance_threshold > 64 / 4 ) 2203 edge_distance_threshold = 64 / 4; 2204 2205 edge_distance_threshold = FT_DivFix( edge_distance_threshold, 2206 scale ); 2207 2208 for ( seg = segments; seg < segment_limit; seg++ ) 2209 { 2210 AF_Edge found = NULL; 2211 FT_UInt ee; 2212 2213 2214 /* ignore too short segments, too wide ones, and, in this loop, */ 2215 /* one-point segments without a direction */ 2216 if ( seg->height < segment_length_threshold || 2217 seg->delta > segment_width_threshold || 2218 seg->dir == AF_DIR_NONE ) 2219 continue; 2220 2221 /* A special case for serif edges: If they are smaller than */ 2222 /* 1.5 pixels we ignore them. */ 2223 if ( seg->serif && 2224 2 * seg->height < 3 * segment_length_threshold ) 2225 continue; 2226 2227 /* look for an edge corresponding to the segment */ 2228 for ( ee = 0; ee < axis->num_edges; ee++ ) 2229 { 2230 AF_Edge edge = axis->edges + ee; 2231 FT_Pos dist; 2232 2233 2234 dist = seg->pos - edge->fpos; 2235 if ( dist < 0 ) 2236 dist = -dist; 2237 2238 if ( dist < edge_distance_threshold && edge->dir == seg->dir ) 2239 { 2240 found = edge; 2241 break; 2242 } 2243 } 2244 2245 if ( !found ) 2246 { 2247 AF_Edge edge; 2248 2249 2250 /* insert a new edge in the list and */ 2251 /* sort according to the position */ 2252 error = af_axis_hints_new_edge( axis, seg->pos, 2253 (AF_Direction)seg->dir, 2254 top_to_bottom_hinting, 2255 memory, &edge ); 2256 if ( error ) 2257 goto Exit; 2258 2259 /* add the segment to the new edge's list */ 2260 FT_ZERO( edge ); 2261 2262 edge->first = seg; 2263 edge->last = seg; 2264 edge->dir = seg->dir; 2265 edge->fpos = seg->pos; 2266 edge->opos = FT_MulFix( seg->pos, scale ); 2267 edge->pos = edge->opos; 2268 seg->edge_next = seg; 2269 } 2270 else 2271 { 2272 /* if an edge was found, simply add the segment to the edge's */ 2273 /* list */ 2274 seg->edge_next = found->first; 2275 found->last->edge_next = seg; 2276 found->last = seg; 2277 } 2278 } 2279 2280 /* we loop again over all segments to catch one-point segments */ 2281 /* without a direction: if possible, link them to existing edges */ 2282 for ( seg = segments; seg < segment_limit; seg++ ) 2283 { 2284 AF_Edge found = NULL; 2285 FT_UInt ee; 2286 2287 2288 if ( seg->dir != AF_DIR_NONE ) 2289 continue; 2290 2291 /* look for an edge corresponding to the segment */ 2292 for ( ee = 0; ee < axis->num_edges; ee++ ) 2293 { 2294 AF_Edge edge = axis->edges + ee; 2295 FT_Pos dist; 2296 2297 2298 dist = seg->pos - edge->fpos; 2299 if ( dist < 0 ) 2300 dist = -dist; 2301 2302 if ( dist < edge_distance_threshold ) 2303 { 2304 found = edge; 2305 break; 2306 } 2307 } 2308 2309 /* one-point segments without a match are ignored */ 2310 if ( found ) 2311 { 2312 seg->edge_next = found->first; 2313 found->last->edge_next = seg; 2314 found->last = seg; 2315 } 2316 } 2317 2318 2319 /******************************************************************* 2320 * 2321 * Good, we now compute each edge's properties according to the 2322 * segments found on its position. Basically, these are 2323 * 2324 * - the edge's main direction 2325 * - stem edge, serif edge or both (which defaults to stem then) 2326 * - rounded edge, straight or both (which defaults to straight) 2327 * - link for edge 2328 * 2329 */ 2330 2331 /* first of all, set the `edge' field in each segment -- this is */ 2332 /* required in order to compute edge links */ 2333 2334 /* 2335 * Note that removing this loop and setting the `edge' field of each 2336 * segment directly in the code above slows down execution speed for 2337 * some reasons on platforms like the Sun. 2338 */ 2339 { 2340 AF_Edge edges = axis->edges; 2341 AF_Edge edge_limit = FT_OFFSET( edges, axis->num_edges ); 2342 AF_Edge edge; 2343 2344 2345 for ( edge = edges; edge < edge_limit; edge++ ) 2346 { 2347 seg = edge->first; 2348 if ( seg ) 2349 do 2350 { 2351 seg->edge = edge; 2352 seg = seg->edge_next; 2353 2354 } while ( seg != edge->first ); 2355 } 2356 2357 /* now compute each edge properties */ 2358 for ( edge = edges; edge < edge_limit; edge++ ) 2359 { 2360 FT_Int is_round = 0; /* does it contain round segments? */ 2361 FT_Int is_straight = 0; /* does it contain straight segments? */ 2362 #if 0 2363 FT_Pos ups = 0; /* number of upwards segments */ 2364 FT_Pos downs = 0; /* number of downwards segments */ 2365 #endif 2366 2367 2368 seg = edge->first; 2369 2370 do 2371 { 2372 FT_Bool is_serif; 2373 2374 2375 /* check for roundness of segment */ 2376 if ( seg->flags & AF_EDGE_ROUND ) 2377 is_round++; 2378 else 2379 is_straight++; 2380 2381 #if 0 2382 /* check for segment direction */ 2383 if ( seg->dir == up_dir ) 2384 ups += seg->max_coord - seg->min_coord; 2385 else 2386 downs += seg->max_coord - seg->min_coord; 2387 #endif 2388 2389 /* check for links -- if seg->serif is set, then seg->link must */ 2390 /* be ignored */ 2391 is_serif = FT_BOOL( seg->serif && 2392 seg->serif->edge && 2393 seg->serif->edge != edge ); 2394 2395 if ( ( seg->link && seg->link->edge ) || is_serif ) 2396 { 2397 AF_Edge edge2; 2398 AF_Segment seg2; 2399 2400 2401 edge2 = edge->link; 2402 seg2 = seg->link; 2403 2404 if ( is_serif ) 2405 { 2406 seg2 = seg->serif; 2407 edge2 = edge->serif; 2408 } 2409 2410 if ( edge2 ) 2411 { 2412 FT_Pos edge_delta; 2413 FT_Pos seg_delta; 2414 2415 2416 edge_delta = edge->fpos - edge2->fpos; 2417 if ( edge_delta < 0 ) 2418 edge_delta = -edge_delta; 2419 2420 seg_delta = seg->pos - seg2->pos; 2421 if ( seg_delta < 0 ) 2422 seg_delta = -seg_delta; 2423 2424 if ( seg_delta < edge_delta ) 2425 edge2 = seg2->edge; 2426 } 2427 else 2428 edge2 = seg2->edge; 2429 2430 if ( is_serif ) 2431 { 2432 edge->serif = edge2; 2433 edge2->flags |= AF_EDGE_SERIF; 2434 } 2435 else 2436 edge->link = edge2; 2437 } 2438 2439 seg = seg->edge_next; 2440 2441 } while ( seg != edge->first ); 2442 2443 /* set the round/straight flags */ 2444 edge->flags = AF_EDGE_NORMAL; 2445 2446 if ( is_round > 0 && is_round >= is_straight ) 2447 edge->flags |= AF_EDGE_ROUND; 2448 2449 #if 0 2450 /* set the edge's main direction */ 2451 edge->dir = AF_DIR_NONE; 2452 2453 if ( ups > downs ) 2454 edge->dir = (FT_Char)up_dir; 2455 2456 else if ( ups < downs ) 2457 edge->dir = (FT_Char)-up_dir; 2458 2459 else if ( ups == downs ) 2460 edge->dir = 0; /* both up and down! */ 2461 #endif 2462 2463 /* get rid of serifs if link is set */ 2464 /* XXX: This gets rid of many unpleasant artefacts! */ 2465 /* Example: the `c' in cour.pfa at size 13 */ 2466 2467 if ( edge->serif && edge->link ) 2468 edge->serif = NULL; 2469 } 2470 } 2471 2472 Exit: 2473 return error; 2474 } 2475 2476 2477 /* Detect segments and edges for given dimension. */ 2478 2479 FT_LOCAL_DEF( FT_Error ) af_latin_hints_detect_features(AF_GlyphHints hints,FT_UInt width_count,AF_WidthRec * widths,AF_Dimension dim)2480 af_latin_hints_detect_features( AF_GlyphHints hints, 2481 FT_UInt width_count, 2482 AF_WidthRec* widths, 2483 AF_Dimension dim ) 2484 { 2485 FT_Error error; 2486 2487 2488 error = af_latin_hints_compute_segments( hints, dim ); 2489 if ( !error ) 2490 { 2491 af_latin_hints_link_segments( hints, width_count, widths, dim ); 2492 2493 error = af_latin_hints_compute_edges( hints, dim ); 2494 } 2495 2496 return error; 2497 } 2498 2499 2500 /* Compute all edges which lie within blue zones. */ 2501 2502 static void af_latin_hints_compute_blue_edges(AF_GlyphHints hints,AF_LatinMetrics metrics)2503 af_latin_hints_compute_blue_edges( AF_GlyphHints hints, 2504 AF_LatinMetrics metrics ) 2505 { 2506 AF_AxisHints axis = &hints->axis[AF_DIMENSION_VERT]; 2507 AF_Edge edge = axis->edges; 2508 AF_Edge edge_limit = FT_OFFSET( edge, axis->num_edges ); 2509 AF_LatinAxis latin = &metrics->axis[AF_DIMENSION_VERT]; 2510 FT_Fixed scale = latin->scale; 2511 2512 2513 /* compute which blue zones are active, i.e. have their scaled */ 2514 /* size < 3/4 pixels */ 2515 2516 /* for each horizontal edge search the blue zone which is closest */ 2517 for ( ; edge < edge_limit; edge++ ) 2518 { 2519 FT_UInt bb; 2520 AF_Width best_blue = NULL; 2521 FT_Bool best_blue_is_neutral = 0; 2522 FT_Pos best_dist; /* initial threshold */ 2523 2524 2525 /* compute the initial threshold as a fraction of the EM size */ 2526 /* (the value 40 is heuristic) */ 2527 best_dist = FT_MulFix( metrics->units_per_em / 40, scale ); 2528 2529 /* assure a minimum distance of 0.5px */ 2530 if ( best_dist > 64 / 2 ) 2531 best_dist = 64 / 2; 2532 2533 for ( bb = 0; bb < latin->blue_count; bb++ ) 2534 { 2535 AF_LatinBlue blue = latin->blues + bb; 2536 FT_Bool is_top_blue, is_neutral_blue, is_major_dir; 2537 2538 2539 /* skip inactive blue zones (i.e., those that are too large) */ 2540 if ( !( blue->flags & AF_LATIN_BLUE_ACTIVE ) ) 2541 continue; 2542 2543 /* if it is a top zone, check for right edges (against the major */ 2544 /* direction); if it is a bottom zone, check for left edges (in */ 2545 /* the major direction) -- this assumes the TrueType convention */ 2546 /* for the orientation of contours */ 2547 is_top_blue = 2548 (FT_Byte)( ( blue->flags & ( AF_LATIN_BLUE_TOP | 2549 AF_LATIN_BLUE_SUB_TOP ) ) != 0 ); 2550 is_neutral_blue = 2551 (FT_Byte)( ( blue->flags & AF_LATIN_BLUE_NEUTRAL ) != 0); 2552 is_major_dir = 2553 FT_BOOL( edge->dir == axis->major_dir ); 2554 2555 /* neutral blue zones are handled for both directions */ 2556 if ( is_top_blue ^ is_major_dir || is_neutral_blue ) 2557 { 2558 FT_Pos dist; 2559 2560 2561 /* first of all, compare it to the reference position */ 2562 dist = edge->fpos - blue->ref.org; 2563 if ( dist < 0 ) 2564 dist = -dist; 2565 2566 dist = FT_MulFix( dist, scale ); 2567 if ( dist < best_dist ) 2568 { 2569 best_dist = dist; 2570 best_blue = &blue->ref; 2571 best_blue_is_neutral = is_neutral_blue; 2572 } 2573 2574 /* now compare it to the overshoot position and check whether */ 2575 /* the edge is rounded, and whether the edge is over the */ 2576 /* reference position of a top zone, or under the reference */ 2577 /* position of a bottom zone (provided we don't have a */ 2578 /* neutral blue zone) */ 2579 if ( edge->flags & AF_EDGE_ROUND && 2580 dist != 0 && 2581 !is_neutral_blue ) 2582 { 2583 FT_Bool is_under_ref = FT_BOOL( edge->fpos < blue->ref.org ); 2584 2585 2586 if ( is_top_blue ^ is_under_ref ) 2587 { 2588 dist = edge->fpos - blue->shoot.org; 2589 if ( dist < 0 ) 2590 dist = -dist; 2591 2592 dist = FT_MulFix( dist, scale ); 2593 if ( dist < best_dist ) 2594 { 2595 best_dist = dist; 2596 best_blue = &blue->shoot; 2597 best_blue_is_neutral = is_neutral_blue; 2598 } 2599 } 2600 } 2601 } 2602 } 2603 2604 if ( best_blue ) 2605 { 2606 edge->blue_edge = best_blue; 2607 if ( best_blue_is_neutral ) 2608 edge->flags |= AF_EDGE_NEUTRAL; 2609 } 2610 } 2611 } 2612 2613 2614 /* Initalize hinting engine. */ 2615 2616 static FT_Error af_latin_hints_init(AF_GlyphHints hints,AF_StyleMetrics metrics_)2617 af_latin_hints_init( AF_GlyphHints hints, 2618 AF_StyleMetrics metrics_ ) /* AF_LatinMetrics */ 2619 { 2620 AF_LatinMetrics metrics = (AF_LatinMetrics)metrics_; 2621 2622 FT_Render_Mode mode; 2623 FT_UInt32 scaler_flags, other_flags; 2624 FT_Face face = metrics->root.scaler.face; 2625 2626 2627 af_glyph_hints_rescale( hints, (AF_StyleMetrics)metrics ); 2628 2629 /* 2630 * correct x_scale and y_scale if needed, since they may have 2631 * been modified by `af_latin_metrics_scale_dim' above 2632 */ 2633 hints->x_scale = metrics->axis[AF_DIMENSION_HORZ].scale; 2634 hints->x_delta = metrics->axis[AF_DIMENSION_HORZ].delta; 2635 hints->y_scale = metrics->axis[AF_DIMENSION_VERT].scale; 2636 hints->y_delta = metrics->axis[AF_DIMENSION_VERT].delta; 2637 2638 /* compute flags depending on render mode, etc. */ 2639 mode = metrics->root.scaler.render_mode; 2640 2641 scaler_flags = hints->scaler_flags; 2642 other_flags = 0; 2643 2644 /* 2645 * We snap the width of vertical stems for the monochrome and 2646 * horizontal LCD rendering targets only. 2647 */ 2648 if ( mode == FT_RENDER_MODE_MONO || mode == FT_RENDER_MODE_LCD ) 2649 other_flags |= AF_LATIN_HINTS_HORZ_SNAP; 2650 2651 /* 2652 * We snap the width of horizontal stems for the monochrome and 2653 * vertical LCD rendering targets only. 2654 */ 2655 if ( mode == FT_RENDER_MODE_MONO || mode == FT_RENDER_MODE_LCD_V ) 2656 other_flags |= AF_LATIN_HINTS_VERT_SNAP; 2657 2658 /* 2659 * We adjust stems to full pixels unless in `light' or `lcd' mode. 2660 */ 2661 if ( mode != FT_RENDER_MODE_LIGHT && mode != FT_RENDER_MODE_LCD ) 2662 other_flags |= AF_LATIN_HINTS_STEM_ADJUST; 2663 2664 if ( mode == FT_RENDER_MODE_MONO ) 2665 other_flags |= AF_LATIN_HINTS_MONO; 2666 2667 /* 2668 * In `light' or `lcd' mode we disable horizontal hinting completely. 2669 * We also do it if the face is italic. 2670 * 2671 * However, if warping is enabled (which only works in `light' hinting 2672 * mode), advance widths get adjusted, too. 2673 */ 2674 if ( mode == FT_RENDER_MODE_LIGHT || mode == FT_RENDER_MODE_LCD || 2675 ( face->style_flags & FT_STYLE_FLAG_ITALIC ) != 0 ) 2676 scaler_flags |= AF_SCALER_FLAG_NO_HORIZONTAL; 2677 2678 hints->scaler_flags = scaler_flags; 2679 hints->other_flags = other_flags; 2680 2681 return FT_Err_Ok; 2682 } 2683 2684 2685 /*************************************************************************/ 2686 /*************************************************************************/ 2687 /***** *****/ 2688 /***** L A T I N G L Y P H G R I D - F I T T I N G *****/ 2689 /***** *****/ 2690 /*************************************************************************/ 2691 /*************************************************************************/ 2692 2693 /* Snap a given width in scaled coordinates to one of the */ 2694 /* current standard widths. */ 2695 2696 static FT_Pos af_latin_snap_width(AF_Width widths,FT_UInt count,FT_Pos width)2697 af_latin_snap_width( AF_Width widths, 2698 FT_UInt count, 2699 FT_Pos width ) 2700 { 2701 FT_UInt n; 2702 FT_Pos best = 64 + 32 + 2; 2703 FT_Pos reference = width; 2704 FT_Pos scaled; 2705 2706 2707 for ( n = 0; n < count; n++ ) 2708 { 2709 FT_Pos w; 2710 FT_Pos dist; 2711 2712 2713 w = widths[n].cur; 2714 dist = width - w; 2715 if ( dist < 0 ) 2716 dist = -dist; 2717 if ( dist < best ) 2718 { 2719 best = dist; 2720 reference = w; 2721 } 2722 } 2723 2724 scaled = FT_PIX_ROUND( reference ); 2725 2726 if ( width >= reference ) 2727 { 2728 if ( width < scaled + 48 ) 2729 width = reference; 2730 } 2731 else 2732 { 2733 if ( width > scaled - 48 ) 2734 width = reference; 2735 } 2736 2737 return width; 2738 } 2739 2740 2741 /* Compute the snapped width of a given stem, ignoring very thin ones. */ 2742 /* There is a lot of voodoo in this function; changing the hard-coded */ 2743 /* parameters influence the whole hinting process. */ 2744 2745 static FT_Pos af_latin_compute_stem_width(AF_GlyphHints hints,AF_Dimension dim,FT_Pos width,FT_Pos base_delta,FT_UInt base_flags,FT_UInt stem_flags)2746 af_latin_compute_stem_width( AF_GlyphHints hints, 2747 AF_Dimension dim, 2748 FT_Pos width, 2749 FT_Pos base_delta, 2750 FT_UInt base_flags, 2751 FT_UInt stem_flags ) 2752 { 2753 AF_LatinMetrics metrics = (AF_LatinMetrics)hints->metrics; 2754 AF_LatinAxis axis = &metrics->axis[dim]; 2755 FT_Pos dist = width; 2756 FT_Int sign = 0; 2757 FT_Int vertical = ( dim == AF_DIMENSION_VERT ); 2758 2759 2760 if ( !AF_LATIN_HINTS_DO_STEM_ADJUST( hints ) || 2761 axis->extra_light ) 2762 return width; 2763 2764 if ( dist < 0 ) 2765 { 2766 dist = -width; 2767 sign = 1; 2768 } 2769 2770 if ( ( vertical && !AF_LATIN_HINTS_DO_VERT_SNAP( hints ) ) || 2771 ( !vertical && !AF_LATIN_HINTS_DO_HORZ_SNAP( hints ) ) ) 2772 { 2773 /* smooth hinting process: very lightly quantize the stem width */ 2774 2775 /* leave the widths of serifs alone */ 2776 if ( ( stem_flags & AF_EDGE_SERIF ) && 2777 vertical && 2778 ( dist < 3 * 64 ) ) 2779 goto Done_Width; 2780 2781 else if ( base_flags & AF_EDGE_ROUND ) 2782 { 2783 if ( dist < 80 ) 2784 dist = 64; 2785 } 2786 else if ( dist < 56 ) 2787 dist = 56; 2788 2789 if ( axis->width_count > 0 ) 2790 { 2791 FT_Pos delta; 2792 2793 2794 /* compare to standard width */ 2795 delta = dist - axis->widths[0].cur; 2796 2797 if ( delta < 0 ) 2798 delta = -delta; 2799 2800 if ( delta < 40 ) 2801 { 2802 dist = axis->widths[0].cur; 2803 if ( dist < 48 ) 2804 dist = 48; 2805 2806 goto Done_Width; 2807 } 2808 2809 if ( dist < 3 * 64 ) 2810 { 2811 delta = dist & 63; 2812 dist &= -64; 2813 2814 if ( delta < 10 ) 2815 dist += delta; 2816 2817 else if ( delta < 32 ) 2818 dist += 10; 2819 2820 else if ( delta < 54 ) 2821 dist += 54; 2822 2823 else 2824 dist += delta; 2825 } 2826 else 2827 { 2828 /* A stem's end position depends on two values: the start */ 2829 /* position and the stem length. The former gets usually */ 2830 /* rounded to the grid, while the latter gets rounded also if it */ 2831 /* exceeds a certain length (see below in this function). This */ 2832 /* `double rounding' can lead to a great difference to the */ 2833 /* original, unhinted position; this normally doesn't matter for */ 2834 /* large PPEM values, but for small sizes it can easily make */ 2835 /* outlines collide. For this reason, we adjust the stem length */ 2836 /* by a small amount depending on the PPEM value in case the */ 2837 /* former and latter rounding both point into the same */ 2838 /* direction. */ 2839 2840 FT_Pos bdelta = 0; 2841 2842 2843 if ( ( ( width > 0 ) && ( base_delta > 0 ) ) || 2844 ( ( width < 0 ) && ( base_delta < 0 ) ) ) 2845 { 2846 FT_UInt ppem = metrics->root.scaler.face->size->metrics.x_ppem; 2847 2848 2849 if ( ppem < 10 ) 2850 bdelta = base_delta; 2851 else if ( ppem < 30 ) 2852 bdelta = ( base_delta * (FT_Pos)( 30 - ppem ) ) / 20; 2853 2854 if ( bdelta < 0 ) 2855 bdelta = -bdelta; 2856 } 2857 2858 dist = ( dist - bdelta + 32 ) & ~63; 2859 } 2860 } 2861 } 2862 else 2863 { 2864 /* strong hinting process: snap the stem width to integer pixels */ 2865 2866 FT_Pos org_dist = dist; 2867 2868 2869 dist = af_latin_snap_width( axis->widths, axis->width_count, dist ); 2870 2871 if ( vertical ) 2872 { 2873 /* in the case of vertical hinting, always round */ 2874 /* the stem heights to integer pixels */ 2875 2876 if ( dist >= 64 ) 2877 dist = ( dist + 16 ) & ~63; 2878 else 2879 dist = 64; 2880 } 2881 else 2882 { 2883 if ( AF_LATIN_HINTS_DO_MONO( hints ) ) 2884 { 2885 /* monochrome horizontal hinting: snap widths to integer pixels */ 2886 /* with a different threshold */ 2887 2888 if ( dist < 64 ) 2889 dist = 64; 2890 else 2891 dist = ( dist + 32 ) & ~63; 2892 } 2893 else 2894 { 2895 /* for horizontal anti-aliased hinting, we adopt a more subtle */ 2896 /* approach: we strengthen small stems, round stems whose size */ 2897 /* is between 1 and 2 pixels to an integer, otherwise nothing */ 2898 2899 if ( dist < 48 ) 2900 dist = ( dist + 64 ) >> 1; 2901 2902 else if ( dist < 128 ) 2903 { 2904 /* We only round to an integer width if the corresponding */ 2905 /* distortion is less than 1/4 pixel. Otherwise this */ 2906 /* makes everything worse since the diagonals, which are */ 2907 /* not hinted, appear a lot bolder or thinner than the */ 2908 /* vertical stems. */ 2909 2910 FT_Pos delta; 2911 2912 2913 dist = ( dist + 22 ) & ~63; 2914 delta = dist - org_dist; 2915 if ( delta < 0 ) 2916 delta = -delta; 2917 2918 if ( delta >= 16 ) 2919 { 2920 dist = org_dist; 2921 if ( dist < 48 ) 2922 dist = ( dist + 64 ) >> 1; 2923 } 2924 } 2925 else 2926 /* round otherwise to prevent color fringes in LCD mode */ 2927 dist = ( dist + 32 ) & ~63; 2928 } 2929 } 2930 } 2931 2932 Done_Width: 2933 if ( sign ) 2934 dist = -dist; 2935 2936 return dist; 2937 } 2938 2939 2940 /* Align one stem edge relative to the previous stem edge. */ 2941 2942 static void af_latin_align_linked_edge(AF_GlyphHints hints,AF_Dimension dim,AF_Edge base_edge,AF_Edge stem_edge)2943 af_latin_align_linked_edge( AF_GlyphHints hints, 2944 AF_Dimension dim, 2945 AF_Edge base_edge, 2946 AF_Edge stem_edge ) 2947 { 2948 FT_Pos dist, base_delta; 2949 FT_Pos fitted_width; 2950 2951 2952 dist = stem_edge->opos - base_edge->opos; 2953 base_delta = base_edge->pos - base_edge->opos; 2954 2955 fitted_width = af_latin_compute_stem_width( hints, dim, 2956 dist, base_delta, 2957 base_edge->flags, 2958 stem_edge->flags ); 2959 2960 2961 stem_edge->pos = base_edge->pos + fitted_width; 2962 2963 FT_TRACE5(( " LINK: edge %td (opos=%.2f) linked to %.2f," 2964 " dist was %.2f, now %.2f\n", 2965 stem_edge - hints->axis[dim].edges, 2966 (double)stem_edge->opos / 64, (double)stem_edge->pos / 64, 2967 (double)dist / 64, (double)fitted_width / 64 )); 2968 } 2969 2970 2971 /* Shift the coordinates of the `serif' edge by the same amount */ 2972 /* as the corresponding `base' edge has been moved already. */ 2973 2974 static void af_latin_align_serif_edge(AF_GlyphHints hints,AF_Edge base,AF_Edge serif)2975 af_latin_align_serif_edge( AF_GlyphHints hints, 2976 AF_Edge base, 2977 AF_Edge serif ) 2978 { 2979 FT_UNUSED( hints ); 2980 2981 serif->pos = base->pos + ( serif->opos - base->opos ); 2982 } 2983 2984 2985 /*************************************************************************/ 2986 /*************************************************************************/ 2987 /*************************************************************************/ 2988 /**** ****/ 2989 /**** E D G E H I N T I N G ****/ 2990 /**** ****/ 2991 /*************************************************************************/ 2992 /*************************************************************************/ 2993 /*************************************************************************/ 2994 2995 2996 /* The main grid-fitting routine. */ 2997 2998 static void af_latin_hint_edges(AF_GlyphHints hints,AF_Dimension dim)2999 af_latin_hint_edges( AF_GlyphHints hints, 3000 AF_Dimension dim ) 3001 { 3002 AF_AxisHints axis = &hints->axis[dim]; 3003 AF_Edge edges = axis->edges; 3004 AF_Edge edge_limit = FT_OFFSET( edges, axis->num_edges ); 3005 FT_PtrDist n_edges; 3006 AF_Edge edge; 3007 AF_Edge anchor = NULL; 3008 FT_Int has_serifs = 0; 3009 3010 AF_StyleClass style_class = hints->metrics->style_class; 3011 AF_ScriptClass script_class = af_script_classes[style_class->script]; 3012 3013 FT_Bool top_to_bottom_hinting = 0; 3014 3015 #ifdef FT_DEBUG_LEVEL_TRACE 3016 FT_UInt num_actions = 0; 3017 #endif 3018 3019 3020 FT_TRACE5(( "latin %s edge hinting (style `%s')\n", 3021 dim == AF_DIMENSION_VERT ? "horizontal" : "vertical", 3022 af_style_names[hints->metrics->style_class->style] )); 3023 3024 if ( dim == AF_DIMENSION_VERT ) 3025 top_to_bottom_hinting = script_class->top_to_bottom_hinting; 3026 3027 /* we begin by aligning all stems relative to the blue zone */ 3028 /* if needed -- that's only for horizontal edges */ 3029 3030 if ( dim == AF_DIMENSION_VERT && AF_HINTS_DO_BLUES( hints ) ) 3031 { 3032 for ( edge = edges; edge < edge_limit; edge++ ) 3033 { 3034 AF_Width blue; 3035 AF_Edge edge1, edge2; /* these edges form the stem to check */ 3036 3037 3038 if ( edge->flags & AF_EDGE_DONE ) 3039 continue; 3040 3041 edge1 = NULL; 3042 edge2 = edge->link; 3043 3044 /* 3045 * If a stem contains both a neutral and a non-neutral blue zone, 3046 * skip the neutral one. Otherwise, outlines with different 3047 * directions might be incorrectly aligned at the same vertical 3048 * position. 3049 * 3050 * If we have two neutral blue zones, skip one of them. 3051 * 3052 */ 3053 if ( edge->blue_edge && edge2 && edge2->blue_edge ) 3054 { 3055 FT_Byte neutral = edge->flags & AF_EDGE_NEUTRAL; 3056 FT_Byte neutral2 = edge2->flags & AF_EDGE_NEUTRAL; 3057 3058 3059 if ( neutral2 ) 3060 { 3061 edge2->blue_edge = NULL; 3062 edge2->flags &= ~AF_EDGE_NEUTRAL; 3063 } 3064 else if ( neutral ) 3065 { 3066 edge->blue_edge = NULL; 3067 edge->flags &= ~AF_EDGE_NEUTRAL; 3068 } 3069 } 3070 3071 blue = edge->blue_edge; 3072 if ( blue ) 3073 edge1 = edge; 3074 3075 /* flip edges if the other edge is aligned to a blue zone */ 3076 else if ( edge2 && edge2->blue_edge ) 3077 { 3078 blue = edge2->blue_edge; 3079 edge1 = edge2; 3080 edge2 = edge; 3081 } 3082 3083 if ( !edge1 ) 3084 continue; 3085 3086 #ifdef FT_DEBUG_LEVEL_TRACE 3087 if ( !anchor ) 3088 FT_TRACE5(( " BLUE_ANCHOR: edge %td (opos=%.2f) snapped to %.2f," 3089 " was %.2f (anchor=edge %td)\n", 3090 edge1 - edges, 3091 (double)edge1->opos / 64, (double)blue->fit / 64, 3092 (double)edge1->pos / 64, edge - edges )); 3093 else 3094 FT_TRACE5(( " BLUE: edge %td (opos=%.2f) snapped to %.2f," 3095 " was %.2f\n", 3096 edge1 - edges, 3097 (double)edge1->opos / 64, (double)blue->fit / 64, 3098 (double)edge1->pos / 64 )); 3099 3100 num_actions++; 3101 #endif 3102 3103 edge1->pos = blue->fit; 3104 edge1->flags |= AF_EDGE_DONE; 3105 3106 if ( edge2 && !edge2->blue_edge ) 3107 { 3108 af_latin_align_linked_edge( hints, dim, edge1, edge2 ); 3109 edge2->flags |= AF_EDGE_DONE; 3110 3111 #ifdef FT_DEBUG_LEVEL_TRACE 3112 num_actions++; 3113 #endif 3114 } 3115 3116 if ( !anchor ) 3117 anchor = edge; 3118 } 3119 } 3120 3121 /* now we align all other stem edges, trying to maintain the */ 3122 /* relative order of stems in the glyph */ 3123 for ( edge = edges; edge < edge_limit; edge++ ) 3124 { 3125 AF_Edge edge2; 3126 3127 3128 if ( edge->flags & AF_EDGE_DONE ) 3129 continue; 3130 3131 /* skip all non-stem edges */ 3132 edge2 = edge->link; 3133 if ( !edge2 ) 3134 { 3135 has_serifs++; 3136 continue; 3137 } 3138 3139 /* now align the stem */ 3140 3141 /* this should not happen, but it's better to be safe */ 3142 if ( edge2->blue_edge ) 3143 { 3144 FT_TRACE5(( " ASSERTION FAILED for edge %td\n", edge2 - edges )); 3145 3146 af_latin_align_linked_edge( hints, dim, edge2, edge ); 3147 edge->flags |= AF_EDGE_DONE; 3148 3149 #ifdef FT_DEBUG_LEVEL_TRACE 3150 num_actions++; 3151 #endif 3152 continue; 3153 } 3154 3155 if ( !anchor ) 3156 { 3157 /* if we reach this if clause, no stem has been aligned yet */ 3158 3159 FT_Pos org_len, org_center, cur_len; 3160 FT_Pos cur_pos1, error1, error2, u_off, d_off; 3161 3162 3163 org_len = edge2->opos - edge->opos; 3164 cur_len = af_latin_compute_stem_width( hints, dim, 3165 org_len, 0, 3166 edge->flags, 3167 edge2->flags ); 3168 3169 /* some voodoo to specially round edges for small stem widths; */ 3170 /* the idea is to align the center of a stem, then shifting */ 3171 /* the stem edges to suitable positions */ 3172 if ( cur_len <= 64 ) 3173 { 3174 /* width <= 1px */ 3175 u_off = 32; 3176 d_off = 32; 3177 } 3178 else 3179 { 3180 /* 1px < width < 1.5px */ 3181 u_off = 38; 3182 d_off = 26; 3183 } 3184 3185 if ( cur_len < 96 ) 3186 { 3187 org_center = edge->opos + ( org_len >> 1 ); 3188 cur_pos1 = FT_PIX_ROUND( org_center ); 3189 3190 error1 = org_center - ( cur_pos1 - u_off ); 3191 if ( error1 < 0 ) 3192 error1 = -error1; 3193 3194 error2 = org_center - ( cur_pos1 + d_off ); 3195 if ( error2 < 0 ) 3196 error2 = -error2; 3197 3198 if ( error1 < error2 ) 3199 cur_pos1 -= u_off; 3200 else 3201 cur_pos1 += d_off; 3202 3203 edge->pos = cur_pos1 - cur_len / 2; 3204 edge2->pos = edge->pos + cur_len; 3205 } 3206 else 3207 edge->pos = FT_PIX_ROUND( edge->opos ); 3208 3209 anchor = edge; 3210 edge->flags |= AF_EDGE_DONE; 3211 3212 FT_TRACE5(( " ANCHOR: edge %td (opos=%.2f) and %td (opos=%.2f)" 3213 " snapped to %.2f and %.2f\n", 3214 edge - edges, (double)edge->opos / 64, 3215 edge2 - edges, (double)edge2->opos / 64, 3216 (double)edge->pos / 64, (double)edge2->pos / 64 )); 3217 3218 af_latin_align_linked_edge( hints, dim, edge, edge2 ); 3219 3220 #ifdef FT_DEBUG_LEVEL_TRACE 3221 num_actions += 2; 3222 #endif 3223 } 3224 else 3225 { 3226 FT_Pos org_pos, org_len, org_center, cur_len; 3227 FT_Pos cur_pos1, cur_pos2, delta1, delta2; 3228 3229 3230 org_pos = anchor->pos + ( edge->opos - anchor->opos ); 3231 org_len = edge2->opos - edge->opos; 3232 org_center = org_pos + ( org_len >> 1 ); 3233 3234 cur_len = af_latin_compute_stem_width( hints, dim, 3235 org_len, 0, 3236 edge->flags, 3237 edge2->flags ); 3238 3239 if ( edge2->flags & AF_EDGE_DONE ) 3240 { 3241 FT_TRACE5(( " ADJUST: edge %td (pos=%.2f) moved to %.2f\n", 3242 edge - edges, (double)edge->pos / 64, 3243 (double)( edge2->pos - cur_len ) / 64 )); 3244 3245 edge->pos = edge2->pos - cur_len; 3246 } 3247 3248 else if ( cur_len < 96 ) 3249 { 3250 FT_Pos u_off, d_off; 3251 3252 3253 cur_pos1 = FT_PIX_ROUND( org_center ); 3254 3255 if ( cur_len <= 64 ) 3256 { 3257 u_off = 32; 3258 d_off = 32; 3259 } 3260 else 3261 { 3262 u_off = 38; 3263 d_off = 26; 3264 } 3265 3266 delta1 = org_center - ( cur_pos1 - u_off ); 3267 if ( delta1 < 0 ) 3268 delta1 = -delta1; 3269 3270 delta2 = org_center - ( cur_pos1 + d_off ); 3271 if ( delta2 < 0 ) 3272 delta2 = -delta2; 3273 3274 if ( delta1 < delta2 ) 3275 cur_pos1 -= u_off; 3276 else 3277 cur_pos1 += d_off; 3278 3279 edge->pos = cur_pos1 - cur_len / 2; 3280 edge2->pos = cur_pos1 + cur_len / 2; 3281 3282 FT_TRACE5(( " STEM: edge %td (opos=%.2f) linked to %td (opos=%.2f)" 3283 " snapped to %.2f and %.2f\n", 3284 edge - edges, (double)edge->opos / 64, 3285 edge2 - edges, (double)edge2->opos / 64, 3286 (double)edge->pos / 64, (double)edge2->pos / 64 )); 3287 } 3288 3289 else 3290 { 3291 org_pos = anchor->pos + ( edge->opos - anchor->opos ); 3292 org_len = edge2->opos - edge->opos; 3293 org_center = org_pos + ( org_len >> 1 ); 3294 3295 cur_len = af_latin_compute_stem_width( hints, dim, 3296 org_len, 0, 3297 edge->flags, 3298 edge2->flags ); 3299 3300 cur_pos1 = FT_PIX_ROUND( org_pos ); 3301 delta1 = cur_pos1 + ( cur_len >> 1 ) - org_center; 3302 if ( delta1 < 0 ) 3303 delta1 = -delta1; 3304 3305 cur_pos2 = FT_PIX_ROUND( org_pos + org_len ) - cur_len; 3306 delta2 = cur_pos2 + ( cur_len >> 1 ) - org_center; 3307 if ( delta2 < 0 ) 3308 delta2 = -delta2; 3309 3310 edge->pos = ( delta1 < delta2 ) ? cur_pos1 : cur_pos2; 3311 edge2->pos = edge->pos + cur_len; 3312 3313 FT_TRACE5(( " STEM: edge %td (opos=%.2f) linked to %td (opos=%.2f)" 3314 " snapped to %.2f and %.2f\n", 3315 edge - edges, (double)edge->opos / 64, 3316 edge2 - edges, (double)edge2->opos / 64, 3317 (double)edge->pos / 64, (double)edge2->pos / 64 )); 3318 } 3319 3320 #ifdef FT_DEBUG_LEVEL_TRACE 3321 num_actions++; 3322 #endif 3323 3324 edge->flags |= AF_EDGE_DONE; 3325 edge2->flags |= AF_EDGE_DONE; 3326 3327 if ( edge > edges && 3328 ( top_to_bottom_hinting ? ( edge->pos > edge[-1].pos ) 3329 : ( edge->pos < edge[-1].pos ) ) ) 3330 { 3331 /* don't move if stem would (almost) disappear otherwise; */ 3332 /* the ad-hoc value 16 corresponds to 1/4px */ 3333 if ( edge->link && FT_ABS( edge->link->pos - edge[-1].pos ) > 16 ) 3334 { 3335 #ifdef FT_DEBUG_LEVEL_TRACE 3336 FT_TRACE5(( " BOUND: edge %td (pos=%.2f) moved to %.2f\n", 3337 edge - edges, 3338 (double)edge->pos / 64, 3339 (double)edge[-1].pos / 64 )); 3340 3341 num_actions++; 3342 #endif 3343 3344 edge->pos = edge[-1].pos; 3345 } 3346 } 3347 } 3348 } 3349 3350 /* make sure that lowercase m's maintain their symmetry */ 3351 3352 /* In general, lowercase m's have six vertical edges if they are sans */ 3353 /* serif, or twelve if they are with serifs. This implementation is */ 3354 /* based on that assumption, and seems to work very well with most */ 3355 /* faces. However, if for a certain face this assumption is not */ 3356 /* true, the m is just rendered like before. In addition, any stem */ 3357 /* correction will only be applied to symmetrical glyphs (even if the */ 3358 /* glyph is not an m), so the potential for unwanted distortion is */ 3359 /* relatively low. */ 3360 3361 /* We don't handle horizontal edges since we can't easily assure that */ 3362 /* the third (lowest) stem aligns with the base line; it might end up */ 3363 /* one pixel higher or lower. */ 3364 3365 n_edges = edge_limit - edges; 3366 if ( dim == AF_DIMENSION_HORZ && ( n_edges == 6 || n_edges == 12 ) ) 3367 { 3368 AF_Edge edge1, edge2, edge3; 3369 FT_Pos dist1, dist2, span, delta; 3370 3371 3372 if ( n_edges == 6 ) 3373 { 3374 edge1 = edges; 3375 edge2 = edges + 2; 3376 edge3 = edges + 4; 3377 } 3378 else 3379 { 3380 edge1 = edges + 1; 3381 edge2 = edges + 5; 3382 edge3 = edges + 9; 3383 } 3384 3385 dist1 = edge2->opos - edge1->opos; 3386 dist2 = edge3->opos - edge2->opos; 3387 3388 span = dist1 - dist2; 3389 if ( span < 0 ) 3390 span = -span; 3391 3392 if ( span < 8 ) 3393 { 3394 delta = edge3->pos - ( 2 * edge2->pos - edge1->pos ); 3395 edge3->pos -= delta; 3396 if ( edge3->link ) 3397 edge3->link->pos -= delta; 3398 3399 /* move the serifs along with the stem */ 3400 if ( n_edges == 12 ) 3401 { 3402 ( edges + 8 )->pos -= delta; 3403 ( edges + 11 )->pos -= delta; 3404 } 3405 3406 edge3->flags |= AF_EDGE_DONE; 3407 if ( edge3->link ) 3408 edge3->link->flags |= AF_EDGE_DONE; 3409 } 3410 } 3411 3412 if ( has_serifs || !anchor ) 3413 { 3414 /* 3415 * now hint the remaining edges (serifs and single) in order 3416 * to complete our processing 3417 */ 3418 for ( edge = edges; edge < edge_limit; edge++ ) 3419 { 3420 FT_Pos delta; 3421 3422 3423 if ( edge->flags & AF_EDGE_DONE ) 3424 continue; 3425 3426 delta = 1000; 3427 3428 if ( edge->serif ) 3429 { 3430 delta = edge->serif->opos - edge->opos; 3431 if ( delta < 0 ) 3432 delta = -delta; 3433 } 3434 3435 if ( delta < 64 + 16 ) 3436 { 3437 af_latin_align_serif_edge( hints, edge->serif, edge ); 3438 FT_TRACE5(( " SERIF: edge %td (opos=%.2f) serif to %td (opos=%.2f)" 3439 " aligned to %.2f\n", 3440 edge - edges, (double)edge->opos / 64, 3441 edge->serif - edges, (double)edge->serif->opos / 64, 3442 (double)edge->pos / 64 )); 3443 } 3444 else if ( !anchor ) 3445 { 3446 edge->pos = FT_PIX_ROUND( edge->opos ); 3447 anchor = edge; 3448 FT_TRACE5(( " SERIF_ANCHOR: edge %td (opos=%.2f)" 3449 " snapped to %.2f\n", 3450 edge - edges, 3451 (double)edge->opos / 64, (double)edge->pos / 64 )); 3452 } 3453 else 3454 { 3455 AF_Edge before, after; 3456 3457 3458 for ( before = edge - 1; before >= edges; before-- ) 3459 if ( before->flags & AF_EDGE_DONE ) 3460 break; 3461 3462 for ( after = edge + 1; after < edge_limit; after++ ) 3463 if ( after->flags & AF_EDGE_DONE ) 3464 break; 3465 3466 if ( before >= edges && before < edge && 3467 after < edge_limit && after > edge ) 3468 { 3469 if ( after->opos == before->opos ) 3470 edge->pos = before->pos; 3471 else 3472 edge->pos = before->pos + 3473 FT_MulDiv( edge->opos - before->opos, 3474 after->pos - before->pos, 3475 after->opos - before->opos ); 3476 3477 FT_TRACE5(( " SERIF_LINK1: edge %td (opos=%.2f) snapped to %.2f" 3478 " from %td (opos=%.2f)\n", 3479 edge - edges, (double)edge->opos / 64, 3480 (double)edge->pos / 64, 3481 before - edges, (double)before->opos / 64 )); 3482 } 3483 else 3484 { 3485 edge->pos = anchor->pos + 3486 ( ( edge->opos - anchor->opos + 16 ) & ~31 ); 3487 FT_TRACE5(( " SERIF_LINK2: edge %td (opos=%.2f)" 3488 " snapped to %.2f\n", 3489 edge - edges, 3490 (double)edge->opos / 64, (double)edge->pos / 64 )); 3491 } 3492 } 3493 3494 #ifdef FT_DEBUG_LEVEL_TRACE 3495 num_actions++; 3496 #endif 3497 edge->flags |= AF_EDGE_DONE; 3498 3499 if ( edge > edges && 3500 ( top_to_bottom_hinting ? ( edge->pos > edge[-1].pos ) 3501 : ( edge->pos < edge[-1].pos ) ) ) 3502 { 3503 /* don't move if stem would (almost) disappear otherwise; */ 3504 /* the ad-hoc value 16 corresponds to 1/4px */ 3505 if ( edge->link && FT_ABS( edge->link->pos - edge[-1].pos ) > 16 ) 3506 { 3507 #ifdef FT_DEBUG_LEVEL_TRACE 3508 FT_TRACE5(( " BOUND: edge %td (pos=%.2f) moved to %.2f\n", 3509 edge - edges, 3510 (double)edge->pos / 64, 3511 (double)edge[-1].pos / 64 )); 3512 3513 num_actions++; 3514 #endif 3515 edge->pos = edge[-1].pos; 3516 } 3517 } 3518 3519 if ( edge + 1 < edge_limit && 3520 edge[1].flags & AF_EDGE_DONE && 3521 ( top_to_bottom_hinting ? ( edge->pos < edge[1].pos ) 3522 : ( edge->pos > edge[1].pos ) ) ) 3523 { 3524 /* don't move if stem would (almost) disappear otherwise; */ 3525 /* the ad-hoc value 16 corresponds to 1/4px */ 3526 if ( edge->link && FT_ABS( edge->link->pos - edge[-1].pos ) > 16 ) 3527 { 3528 #ifdef FT_DEBUG_LEVEL_TRACE 3529 FT_TRACE5(( " BOUND: edge %td (pos=%.2f) moved to %.2f\n", 3530 edge - edges, 3531 (double)edge->pos / 64, 3532 (double)edge[1].pos / 64 )); 3533 3534 num_actions++; 3535 #endif 3536 3537 edge->pos = edge[1].pos; 3538 } 3539 } 3540 } 3541 } 3542 3543 #ifdef FT_DEBUG_LEVEL_TRACE 3544 if ( !num_actions ) 3545 FT_TRACE5(( " (none)\n" )); 3546 FT_TRACE5(( "\n" )); 3547 #endif 3548 } 3549 3550 3551 /* Apply the complete hinting algorithm to a latin glyph. */ 3552 3553 static FT_Error af_latin_hints_apply(FT_UInt glyph_index,AF_GlyphHints hints,FT_Outline * outline,AF_StyleMetrics metrics_)3554 af_latin_hints_apply( FT_UInt glyph_index, 3555 AF_GlyphHints hints, 3556 FT_Outline* outline, 3557 AF_StyleMetrics metrics_ ) /* AF_LatinMetrics */ 3558 { 3559 AF_LatinMetrics metrics = (AF_LatinMetrics)metrics_; 3560 3561 FT_Error error; 3562 int dim; 3563 3564 AF_LatinAxis axis; 3565 3566 3567 error = af_glyph_hints_reload( hints, outline ); 3568 if ( error ) 3569 goto Exit; 3570 3571 /* analyze glyph outline */ 3572 if ( AF_HINTS_DO_HORIZONTAL( hints ) ) 3573 { 3574 axis = &metrics->axis[AF_DIMENSION_HORZ]; 3575 error = af_latin_hints_detect_features( hints, 3576 axis->width_count, 3577 axis->widths, 3578 AF_DIMENSION_HORZ ); 3579 if ( error ) 3580 goto Exit; 3581 } 3582 3583 if ( AF_HINTS_DO_VERTICAL( hints ) ) 3584 { 3585 axis = &metrics->axis[AF_DIMENSION_VERT]; 3586 error = af_latin_hints_detect_features( hints, 3587 axis->width_count, 3588 axis->widths, 3589 AF_DIMENSION_VERT ); 3590 if ( error ) 3591 goto Exit; 3592 3593 /* apply blue zones to base characters only */ 3594 if ( !( metrics->root.globals->glyph_styles[glyph_index] & AF_NONBASE ) ) 3595 af_latin_hints_compute_blue_edges( hints, metrics ); 3596 } 3597 3598 /* grid-fit the outline */ 3599 for ( dim = 0; dim < AF_DIMENSION_MAX; dim++ ) 3600 { 3601 if ( ( dim == AF_DIMENSION_HORZ && AF_HINTS_DO_HORIZONTAL( hints ) ) || 3602 ( dim == AF_DIMENSION_VERT && AF_HINTS_DO_VERTICAL( hints ) ) ) 3603 { 3604 af_latin_hint_edges( hints, (AF_Dimension)dim ); 3605 af_glyph_hints_align_edge_points( hints, (AF_Dimension)dim ); 3606 af_glyph_hints_align_strong_points( hints, (AF_Dimension)dim ); 3607 af_glyph_hints_align_weak_points( hints, (AF_Dimension)dim ); 3608 } 3609 } 3610 3611 af_glyph_hints_save( hints, outline ); 3612 3613 Exit: 3614 return error; 3615 } 3616 3617 3618 /*************************************************************************/ 3619 /*************************************************************************/ 3620 /***** *****/ 3621 /***** L A T I N S C R I P T C L A S S *****/ 3622 /***** *****/ 3623 /*************************************************************************/ 3624 /*************************************************************************/ 3625 3626 3627 AF_DEFINE_WRITING_SYSTEM_CLASS( 3628 af_latin_writing_system_class, 3629 3630 AF_WRITING_SYSTEM_LATIN, 3631 3632 sizeof ( AF_LatinMetricsRec ), 3633 3634 (AF_WritingSystem_InitMetricsFunc) af_latin_metrics_init, /* style_metrics_init */ 3635 (AF_WritingSystem_ScaleMetricsFunc)af_latin_metrics_scale, /* style_metrics_scale */ 3636 (AF_WritingSystem_DoneMetricsFunc) NULL, /* style_metrics_done */ 3637 (AF_WritingSystem_GetStdWidthsFunc)af_latin_get_standard_widths, /* style_metrics_getstdw */ 3638 3639 (AF_WritingSystem_InitHintsFunc) af_latin_hints_init, /* style_hints_init */ 3640 (AF_WritingSystem_ApplyHintsFunc) af_latin_hints_apply /* style_hints_apply */ 3641 ) 3642 3643 3644 /* END */ 3645