1 /***************************************************************************/ 2 /* */ 3 /* aflatin.c */ 4 /* */ 5 /* Auto-fitter hinting routines for latin writing system (body). */ 6 /* */ 7 /* Copyright 2003-2015 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 <ft2build.h> 20 #include FT_ADVANCES_H 21 #include FT_INTERNAL_DEBUG_H 22 23 #include "afglobal.h" 24 #include "afpic.h" 25 #include "aflatin.h" 26 #include "aferrors.h" 27 28 29 #ifdef AF_CONFIG_OPTION_USE_WARPER 30 #include "afwarp.h" 31 #endif 32 33 34 /*************************************************************************/ 35 /* */ 36 /* The macro FT_COMPONENT is used in trace mode. It is an implicit */ 37 /* parameter of the FT_TRACE() and FT_ERROR() macros, used to print/log */ 38 /* messages during execution. */ 39 /* */ 40 #undef FT_COMPONENT 41 #define FT_COMPONENT trace_aflatin 42 43 44 /* needed for computation of round vs. flat segments */ 45 #define FLAT_THRESHOLD( x ) ( x / 14 ) 46 47 48 /*************************************************************************/ 49 /*************************************************************************/ 50 /***** *****/ 51 /***** L A T I N G L O B A L M E T R I C S *****/ 52 /***** *****/ 53 /*************************************************************************/ 54 /*************************************************************************/ 55 56 57 /* Find segments and links, compute all stem widths, and initialize */ 58 /* standard width and height for the glyph with given charcode. */ 59 60 FT_LOCAL_DEF( void ) af_latin_metrics_init_widths(AF_LatinMetrics metrics,FT_Face face)61 af_latin_metrics_init_widths( AF_LatinMetrics metrics, 62 FT_Face face ) 63 { 64 /* scan the array of segments in each direction */ 65 AF_GlyphHintsRec hints[1]; 66 67 68 FT_TRACE5(( "\n" 69 "latin standard widths computation (style `%s')\n" 70 "=====================================================\n" 71 "\n", 72 af_style_names[metrics->root.style_class->style] )); 73 74 af_glyph_hints_init( hints, face->memory ); 75 76 metrics->axis[AF_DIMENSION_HORZ].width_count = 0; 77 metrics->axis[AF_DIMENSION_VERT].width_count = 0; 78 79 { 80 FT_Error error; 81 FT_ULong glyph_index; 82 FT_Long y_offset; 83 int dim; 84 AF_LatinMetricsRec dummy[1]; 85 AF_Scaler scaler = &dummy->root.scaler; 86 87 #ifdef FT_CONFIG_OPTION_PIC 88 AF_FaceGlobals globals = metrics->root.globals; 89 #endif 90 91 AF_StyleClass style_class = metrics->root.style_class; 92 AF_ScriptClass script_class = AF_SCRIPT_CLASSES_GET 93 [style_class->script]; 94 95 FT_UInt32 standard_char; 96 97 98 /* 99 * We check more than a single standard character to catch features 100 * like `c2sc' (small caps from caps) that don't contain lowercase 101 * letters by definition, or other features that mainly operate on 102 * numerals. 103 */ 104 105 standard_char = script_class->standard_char1; 106 af_get_char_index( &metrics->root, 107 standard_char, 108 &glyph_index, 109 &y_offset ); 110 if ( !glyph_index ) 111 { 112 if ( script_class->standard_char2 ) 113 { 114 standard_char = script_class->standard_char2; 115 af_get_char_index( &metrics->root, 116 standard_char, 117 &glyph_index, 118 &y_offset ); 119 if ( !glyph_index ) 120 { 121 if ( script_class->standard_char3 ) 122 { 123 standard_char = script_class->standard_char3; 124 af_get_char_index( &metrics->root, 125 standard_char, 126 &glyph_index, 127 &y_offset ); 128 if ( !glyph_index ) 129 goto Exit; 130 } 131 else 132 goto Exit; 133 } 134 } 135 else 136 goto Exit; 137 } 138 139 FT_TRACE5(( "standard character: U+%04lX (glyph index %d)\n", 140 standard_char, glyph_index )); 141 142 error = FT_Load_Glyph( face, glyph_index, FT_LOAD_NO_SCALE ); 143 if ( error || face->glyph->outline.n_points <= 0 ) 144 goto Exit; 145 146 FT_ZERO( dummy ); 147 148 dummy->units_per_em = metrics->units_per_em; 149 150 scaler->x_scale = 0x10000L; 151 scaler->y_scale = 0x10000L; 152 scaler->x_delta = 0; 153 scaler->y_delta = 0; 154 155 scaler->face = face; 156 scaler->render_mode = FT_RENDER_MODE_NORMAL; 157 scaler->flags = 0; 158 159 af_glyph_hints_rescale( hints, (AF_StyleMetrics)dummy ); 160 161 error = af_glyph_hints_reload( hints, &face->glyph->outline ); 162 if ( error ) 163 goto Exit; 164 165 for ( dim = 0; dim < AF_DIMENSION_MAX; dim++ ) 166 { 167 AF_LatinAxis axis = &metrics->axis[dim]; 168 AF_AxisHints axhints = &hints->axis[dim]; 169 AF_Segment seg, limit, link; 170 FT_UInt num_widths = 0; 171 172 173 error = af_latin_hints_compute_segments( hints, 174 (AF_Dimension)dim ); 175 if ( error ) 176 goto Exit; 177 178 /* 179 * We assume that the glyphs selected for the stem width 180 * computation are `featureless' enough so that the linking 181 * algorithm works fine without adjustments of its scoring 182 * function. 183 */ 184 af_latin_hints_link_segments( hints, 185 0, 186 NULL, 187 (AF_Dimension)dim ); 188 189 seg = axhints->segments; 190 limit = seg + axhints->num_segments; 191 192 for ( ; seg < limit; seg++ ) 193 { 194 link = seg->link; 195 196 /* we only consider stem segments there! */ 197 if ( link && link->link == seg && link > seg ) 198 { 199 FT_Pos dist; 200 201 202 dist = seg->pos - link->pos; 203 if ( dist < 0 ) 204 dist = -dist; 205 206 if ( num_widths < AF_LATIN_MAX_WIDTHS ) 207 axis->widths[num_widths++].org = dist; 208 } 209 } 210 211 /* this also replaces multiple almost identical stem widths */ 212 /* with a single one (the value 100 is heuristic) */ 213 af_sort_and_quantize_widths( &num_widths, axis->widths, 214 dummy->units_per_em / 100 ); 215 axis->width_count = num_widths; 216 } 217 218 Exit: 219 for ( dim = 0; dim < AF_DIMENSION_MAX; dim++ ) 220 { 221 AF_LatinAxis axis = &metrics->axis[dim]; 222 FT_Pos stdw; 223 224 225 stdw = ( axis->width_count > 0 ) ? axis->widths[0].org 226 : AF_LATIN_CONSTANT( metrics, 50 ); 227 228 /* let's try 20% of the smallest width */ 229 axis->edge_distance_threshold = stdw / 5; 230 axis->standard_width = stdw; 231 axis->extra_light = 0; 232 233 #ifdef FT_DEBUG_LEVEL_TRACE 234 { 235 FT_UInt i; 236 237 238 FT_TRACE5(( "%s widths:\n", 239 dim == AF_DIMENSION_VERT ? "horizontal" 240 : "vertical" )); 241 242 FT_TRACE5(( " %d (standard)", axis->standard_width )); 243 for ( i = 1; i < axis->width_count; i++ ) 244 FT_TRACE5(( " %d", axis->widths[i].org )); 245 246 FT_TRACE5(( "\n" )); 247 } 248 #endif 249 } 250 } 251 252 FT_TRACE5(( "\n" )); 253 254 af_glyph_hints_done( hints ); 255 } 256 257 258 /* Find all blue zones. Flat segments give the reference points, */ 259 /* round segments the overshoot positions. */ 260 261 static void af_latin_metrics_init_blues(AF_LatinMetrics metrics,FT_Face face)262 af_latin_metrics_init_blues( AF_LatinMetrics metrics, 263 FT_Face face ) 264 { 265 FT_Pos flats [AF_BLUE_STRING_MAX_LEN]; 266 FT_Pos rounds[AF_BLUE_STRING_MAX_LEN]; 267 268 FT_UInt num_flats; 269 FT_UInt num_rounds; 270 271 AF_LatinBlue blue; 272 FT_Error error; 273 AF_LatinAxis axis = &metrics->axis[AF_DIMENSION_VERT]; 274 FT_Outline outline; 275 276 AF_StyleClass sc = metrics->root.style_class; 277 278 AF_Blue_Stringset bss = sc->blue_stringset; 279 const AF_Blue_StringRec* bs = &af_blue_stringsets[bss]; 280 281 FT_Pos flat_threshold = FLAT_THRESHOLD( metrics->units_per_em ); 282 283 284 /* we walk over the blue character strings as specified in the */ 285 /* style's entry in the `af_blue_stringset' array */ 286 287 FT_TRACE5(( "latin blue zones computation\n" 288 "============================\n" 289 "\n" )); 290 291 for ( ; bs->string != AF_BLUE_STRING_MAX; bs++ ) 292 { 293 const char* p = &af_blue_strings[bs->string]; 294 FT_Pos* blue_ref; 295 FT_Pos* blue_shoot; 296 297 298 #ifdef FT_DEBUG_LEVEL_TRACE 299 { 300 FT_Bool have_flag = 0; 301 302 303 FT_TRACE5(( "blue zone %d", axis->blue_count )); 304 305 if ( bs->properties ) 306 { 307 FT_TRACE5(( " (" )); 308 309 if ( AF_LATIN_IS_TOP_BLUE( bs ) ) 310 { 311 FT_TRACE5(( "top" )); 312 have_flag = 1; 313 } 314 315 if ( AF_LATIN_IS_NEUTRAL_BLUE( bs ) ) 316 { 317 if ( have_flag ) 318 FT_TRACE5(( ", " )); 319 FT_TRACE5(( "neutral" )); 320 have_flag = 1; 321 } 322 323 if ( AF_LATIN_IS_X_HEIGHT_BLUE( bs ) ) 324 { 325 if ( have_flag ) 326 FT_TRACE5(( ", " )); 327 FT_TRACE5(( "small top" )); 328 have_flag = 1; 329 } 330 331 if ( AF_LATIN_IS_LONG_BLUE( bs ) ) 332 { 333 if ( have_flag ) 334 FT_TRACE5(( ", " )); 335 FT_TRACE5(( "long" )); 336 } 337 338 FT_TRACE5(( ")" )); 339 } 340 341 FT_TRACE5(( ":\n" )); 342 } 343 #endif /* FT_DEBUG_LEVEL_TRACE */ 344 345 num_flats = 0; 346 num_rounds = 0; 347 348 while ( *p ) 349 { 350 FT_ULong ch; 351 FT_ULong glyph_index; 352 FT_Long y_offset; 353 FT_Pos best_y; /* same as points.y */ 354 FT_Int best_point, best_contour_first, best_contour_last; 355 FT_Vector* points; 356 FT_Bool round = 0; 357 358 359 GET_UTF8_CHAR( ch, p ); 360 361 /* load the character in the face -- skip unknown or empty ones */ 362 af_get_char_index( &metrics->root, ch, &glyph_index, &y_offset ); 363 if ( glyph_index == 0 ) 364 { 365 FT_TRACE5(( " U+%04lX unavailable\n", ch )); 366 continue; 367 } 368 369 error = FT_Load_Glyph( face, glyph_index, FT_LOAD_NO_SCALE ); 370 outline = face->glyph->outline; 371 /* reject glyphs that don't produce any rendering */ 372 if ( error || outline.n_points <= 2 ) 373 { 374 FT_TRACE5(( " U+%04lX contains no (usable) outlines\n", ch )); 375 continue; 376 } 377 378 /* now compute min or max point indices and coordinates */ 379 points = outline.points; 380 best_point = -1; 381 best_y = 0; /* make compiler happy */ 382 best_contour_first = 0; /* ditto */ 383 best_contour_last = 0; /* ditto */ 384 385 { 386 FT_Int nn; 387 FT_Int first = 0; 388 FT_Int last = -1; 389 390 391 for ( nn = 0; nn < outline.n_contours; first = last + 1, nn++ ) 392 { 393 FT_Int old_best_point = best_point; 394 FT_Int pp; 395 396 397 last = outline.contours[nn]; 398 399 /* Avoid single-point contours since they are never rasterized. */ 400 /* In some fonts, they correspond to mark attachment points */ 401 /* that are way outside of the glyph's real outline. */ 402 if ( last <= first ) 403 continue; 404 405 if ( AF_LATIN_IS_TOP_BLUE( bs ) ) 406 { 407 for ( pp = first; pp <= last; pp++ ) 408 if ( best_point < 0 || points[pp].y > best_y ) 409 { 410 best_point = pp; 411 best_y = points[pp].y; 412 } 413 } 414 else 415 { 416 for ( pp = first; pp <= last; pp++ ) 417 if ( best_point < 0 || points[pp].y < best_y ) 418 { 419 best_point = pp; 420 best_y = points[pp].y; 421 } 422 } 423 424 if ( best_point != old_best_point ) 425 { 426 best_contour_first = first; 427 best_contour_last = last; 428 } 429 } 430 } 431 432 /* now check whether the point belongs to a straight or round */ 433 /* segment; we first need to find in which contour the extremum */ 434 /* lies, then inspect its previous and next points */ 435 if ( best_point >= 0 ) 436 { 437 FT_Pos best_x = points[best_point].x; 438 FT_Int prev, next; 439 FT_Int best_segment_first, best_segment_last; 440 FT_Int best_on_point_first, best_on_point_last; 441 FT_Pos dist; 442 443 444 best_segment_first = best_point; 445 best_segment_last = best_point; 446 447 if ( FT_CURVE_TAG( outline.tags[best_point] ) == FT_CURVE_TAG_ON ) 448 { 449 best_on_point_first = best_point; 450 best_on_point_last = best_point; 451 } 452 else 453 { 454 best_on_point_first = -1; 455 best_on_point_last = -1; 456 } 457 458 /* look for the previous and next points on the contour */ 459 /* that are not on the same Y coordinate, then threshold */ 460 /* the `closeness'... */ 461 prev = best_point; 462 next = prev; 463 464 do 465 { 466 if ( prev > best_contour_first ) 467 prev--; 468 else 469 prev = best_contour_last; 470 471 dist = FT_ABS( points[prev].y - best_y ); 472 /* accept a small distance or a small angle (both values are */ 473 /* heuristic; value 20 corresponds to approx. 2.9 degrees) */ 474 if ( dist > 5 ) 475 if ( FT_ABS( points[prev].x - best_x ) <= 20 * dist ) 476 break; 477 478 best_segment_first = prev; 479 480 if ( FT_CURVE_TAG( outline.tags[prev] ) == FT_CURVE_TAG_ON ) 481 { 482 best_on_point_first = prev; 483 if ( best_on_point_last < 0 ) 484 best_on_point_last = prev; 485 } 486 487 } while ( prev != best_point ); 488 489 do 490 { 491 if ( next < best_contour_last ) 492 next++; 493 else 494 next = best_contour_first; 495 496 dist = FT_ABS( points[next].y - best_y ); 497 if ( dist > 5 ) 498 if ( FT_ABS( points[next].x - best_x ) <= 20 * dist ) 499 break; 500 501 best_segment_last = next; 502 503 if ( FT_CURVE_TAG( outline.tags[next] ) == FT_CURVE_TAG_ON ) 504 { 505 best_on_point_last = next; 506 if ( best_on_point_first < 0 ) 507 best_on_point_first = next; 508 } 509 510 } while ( next != best_point ); 511 512 if ( AF_LATIN_IS_LONG_BLUE( bs ) ) 513 { 514 /* If this flag is set, we have an additional constraint to */ 515 /* get the blue zone distance: Find a segment of the topmost */ 516 /* (or bottommost) contour that is longer than a heuristic */ 517 /* threshold. This ensures that small bumps in the outline */ 518 /* are ignored (for example, the `vertical serifs' found in */ 519 /* many Hebrew glyph designs). */ 520 521 /* If this segment is long enough, we are done. Otherwise, */ 522 /* search the segment next to the extremum that is long */ 523 /* enough, has the same direction, and a not too large */ 524 /* vertical distance from the extremum. Note that the */ 525 /* algorithm doesn't check whether the found segment is */ 526 /* actually the one (vertically) nearest to the extremum. */ 527 528 /* heuristic threshold value */ 529 FT_Pos length_threshold = metrics->units_per_em / 25; 530 531 532 dist = FT_ABS( points[best_segment_last].x - 533 points[best_segment_first].x ); 534 535 if ( dist < length_threshold && 536 best_segment_last - best_segment_first + 2 <= 537 best_contour_last - best_contour_first ) 538 { 539 /* heuristic threshold value */ 540 FT_Pos height_threshold = metrics->units_per_em / 4; 541 542 FT_Int first; 543 FT_Int last; 544 FT_Bool hit; 545 546 /* we intentionally declare these two variables */ 547 /* outside of the loop since various compilers emit */ 548 /* incorrect warning messages otherwise, talking about */ 549 /* `possibly uninitialized variables' */ 550 FT_Int p_first = 0; /* make compiler happy */ 551 FT_Int p_last = 0; 552 553 FT_Bool left2right; 554 555 556 /* compute direction */ 557 prev = best_point; 558 559 do 560 { 561 if ( prev > best_contour_first ) 562 prev--; 563 else 564 prev = best_contour_last; 565 566 if ( points[prev].x != best_x ) 567 break; 568 569 } while ( prev != best_point ); 570 571 /* skip glyph for the degenerate case */ 572 if ( prev == best_point ) 573 continue; 574 575 left2right = FT_BOOL( points[prev].x < points[best_point].x ); 576 577 first = best_segment_last; 578 last = first; 579 hit = 0; 580 581 do 582 { 583 FT_Bool l2r; 584 FT_Pos d; 585 586 587 if ( !hit ) 588 { 589 /* no hit; adjust first point */ 590 first = last; 591 592 /* also adjust first and last on point */ 593 if ( FT_CURVE_TAG( outline.tags[first] ) == 594 FT_CURVE_TAG_ON ) 595 { 596 p_first = first; 597 p_last = first; 598 } 599 else 600 { 601 p_first = -1; 602 p_last = -1; 603 } 604 605 hit = 1; 606 } 607 608 if ( last < best_contour_last ) 609 last++; 610 else 611 last = best_contour_first; 612 613 if ( FT_ABS( best_y - points[first].y ) > height_threshold ) 614 { 615 /* vertical distance too large */ 616 hit = 0; 617 continue; 618 } 619 620 /* same test as above */ 621 dist = FT_ABS( points[last].y - points[first].y ); 622 if ( dist > 5 ) 623 if ( FT_ABS( points[last].x - points[first].x ) <= 624 20 * dist ) 625 { 626 hit = 0; 627 continue; 628 } 629 630 if ( FT_CURVE_TAG( outline.tags[last] ) == FT_CURVE_TAG_ON ) 631 { 632 p_last = last; 633 if ( p_first < 0 ) 634 p_first = last; 635 } 636 637 l2r = FT_BOOL( points[first].x < points[last].x ); 638 d = FT_ABS( points[last].x - points[first].x ); 639 640 if ( l2r == left2right && 641 d >= length_threshold ) 642 { 643 /* all constraints are met; update segment after finding */ 644 /* its end */ 645 do 646 { 647 if ( last < best_contour_last ) 648 last++; 649 else 650 last = best_contour_first; 651 652 d = FT_ABS( points[last].y - points[first].y ); 653 if ( d > 5 ) 654 if ( FT_ABS( points[next].x - points[first].x ) <= 655 20 * dist ) 656 { 657 if ( last > best_contour_first ) 658 last--; 659 else 660 last = best_contour_last; 661 break; 662 } 663 664 p_last = last; 665 666 if ( FT_CURVE_TAG( outline.tags[last] ) == 667 FT_CURVE_TAG_ON ) 668 { 669 p_last = last; 670 if ( p_first < 0 ) 671 p_first = last; 672 } 673 674 } while ( last != best_segment_first ); 675 676 best_y = points[first].y; 677 678 best_segment_first = first; 679 best_segment_last = last; 680 681 best_on_point_first = p_first; 682 best_on_point_last = p_last; 683 684 break; 685 } 686 687 } while ( last != best_segment_first ); 688 } 689 } 690 691 /* for computing blue zones, we add the y offset as returned */ 692 /* by the currently used OpenType feature -- for example, */ 693 /* superscript glyphs might be identical to subscript glyphs */ 694 /* with a vertical shift */ 695 best_y += y_offset; 696 697 FT_TRACE5(( " U+%04lX: best_y = %5ld", ch, best_y )); 698 699 /* now set the `round' flag depending on the segment's kind: */ 700 /* */ 701 /* - if the horizontal distance between the first and last */ 702 /* `on' point is larger than a heuristic threshold */ 703 /* we have a flat segment */ 704 /* - if either the first or the last point of the segment is */ 705 /* an `off' point, the segment is round, otherwise it is */ 706 /* flat */ 707 if ( best_on_point_first >= 0 && 708 best_on_point_last >= 0 && 709 ( FT_ABS( points[best_on_point_last].x - 710 points[best_on_point_first].x ) ) > 711 flat_threshold ) 712 round = 0; 713 else 714 round = FT_BOOL( 715 FT_CURVE_TAG( outline.tags[best_segment_first] ) != 716 FT_CURVE_TAG_ON || 717 FT_CURVE_TAG( outline.tags[best_segment_last] ) != 718 FT_CURVE_TAG_ON ); 719 720 if ( round && AF_LATIN_IS_NEUTRAL_BLUE( bs ) ) 721 { 722 /* only use flat segments for a neutral blue zone */ 723 FT_TRACE5(( " (round, skipped)\n" )); 724 continue; 725 } 726 727 FT_TRACE5(( " (%s)\n", round ? "round" : "flat" )); 728 } 729 730 if ( round ) 731 rounds[num_rounds++] = best_y; 732 else 733 flats[num_flats++] = best_y; 734 } 735 736 if ( num_flats == 0 && num_rounds == 0 ) 737 { 738 /* 739 * we couldn't find a single glyph to compute this blue zone, 740 * we will simply ignore it then 741 */ 742 FT_TRACE5(( " empty\n" )); 743 continue; 744 } 745 746 /* we have computed the contents of the `rounds' and `flats' tables, */ 747 /* now determine the reference and overshoot position of the blue -- */ 748 /* we simply take the median value after a simple sort */ 749 af_sort_pos( num_rounds, rounds ); 750 af_sort_pos( num_flats, flats ); 751 752 blue = &axis->blues[axis->blue_count]; 753 blue_ref = &blue->ref.org; 754 blue_shoot = &blue->shoot.org; 755 756 axis->blue_count++; 757 758 if ( num_flats == 0 ) 759 { 760 *blue_ref = 761 *blue_shoot = rounds[num_rounds / 2]; 762 } 763 else if ( num_rounds == 0 ) 764 { 765 *blue_ref = 766 *blue_shoot = flats[num_flats / 2]; 767 } 768 else 769 { 770 *blue_ref = flats [num_flats / 2]; 771 *blue_shoot = rounds[num_rounds / 2]; 772 } 773 774 /* there are sometimes problems: if the overshoot position of top */ 775 /* zones is under its reference position, or the opposite for bottom */ 776 /* zones. We must thus check everything there and correct the errors */ 777 if ( *blue_shoot != *blue_ref ) 778 { 779 FT_Pos ref = *blue_ref; 780 FT_Pos shoot = *blue_shoot; 781 FT_Bool over_ref = FT_BOOL( shoot > ref ); 782 783 784 if ( AF_LATIN_IS_TOP_BLUE( bs ) ^ over_ref ) 785 { 786 *blue_ref = 787 *blue_shoot = ( shoot + ref ) / 2; 788 789 FT_TRACE5(( " [overshoot smaller than reference," 790 " taking mean value]\n" )); 791 } 792 } 793 794 blue->flags = 0; 795 if ( AF_LATIN_IS_TOP_BLUE( bs ) ) 796 blue->flags |= AF_LATIN_BLUE_TOP; 797 if ( AF_LATIN_IS_NEUTRAL_BLUE( bs ) ) 798 blue->flags |= AF_LATIN_BLUE_NEUTRAL; 799 800 /* 801 * The following flag is used later to adjust the y and x scales 802 * in order to optimize the pixel grid alignment of the top of small 803 * letters. 804 */ 805 if ( AF_LATIN_IS_X_HEIGHT_BLUE( bs ) ) 806 blue->flags |= AF_LATIN_BLUE_ADJUSTMENT; 807 808 FT_TRACE5(( " -> reference = %ld\n" 809 " overshoot = %ld\n", 810 *blue_ref, *blue_shoot )); 811 } 812 813 FT_TRACE5(( "\n" )); 814 815 return; 816 } 817 818 819 /* Check whether all ASCII digits have the same advance width. */ 820 821 FT_LOCAL_DEF( void ) af_latin_metrics_check_digits(AF_LatinMetrics metrics,FT_Face face)822 af_latin_metrics_check_digits( AF_LatinMetrics metrics, 823 FT_Face face ) 824 { 825 FT_UInt i; 826 FT_Bool started = 0, same_width = 1; 827 FT_Fixed advance, old_advance = 0; 828 829 830 /* digit `0' is 0x30 in all supported charmaps */ 831 for ( i = 0x30; i <= 0x39; i++ ) 832 { 833 FT_ULong glyph_index; 834 FT_Long y_offset; 835 836 837 af_get_char_index( &metrics->root, i, &glyph_index, &y_offset ); 838 if ( glyph_index == 0 ) 839 continue; 840 841 if ( FT_Get_Advance( face, glyph_index, 842 FT_LOAD_NO_SCALE | 843 FT_LOAD_NO_HINTING | 844 FT_LOAD_IGNORE_TRANSFORM, 845 &advance ) ) 846 continue; 847 848 if ( started ) 849 { 850 if ( advance != old_advance ) 851 { 852 same_width = 0; 853 break; 854 } 855 } 856 else 857 { 858 old_advance = advance; 859 started = 1; 860 } 861 } 862 863 metrics->root.digits_have_same_width = same_width; 864 } 865 866 867 /* Initialize global metrics. */ 868 869 FT_LOCAL_DEF( FT_Error ) af_latin_metrics_init(AF_LatinMetrics metrics,FT_Face face)870 af_latin_metrics_init( AF_LatinMetrics metrics, 871 FT_Face face ) 872 { 873 FT_CharMap oldmap = face->charmap; 874 875 876 metrics->units_per_em = face->units_per_EM; 877 878 if ( !FT_Select_Charmap( face, FT_ENCODING_UNICODE ) ) 879 { 880 af_latin_metrics_init_widths( metrics, face ); 881 af_latin_metrics_init_blues( metrics, face ); 882 af_latin_metrics_check_digits( metrics, face ); 883 } 884 885 FT_Set_Charmap( face, oldmap ); 886 return FT_Err_Ok; 887 } 888 889 890 /* Adjust scaling value, then scale and shift widths */ 891 /* and blue zones (if applicable) for given dimension. */ 892 893 static void af_latin_metrics_scale_dim(AF_LatinMetrics metrics,AF_Scaler scaler,AF_Dimension dim)894 af_latin_metrics_scale_dim( AF_LatinMetrics metrics, 895 AF_Scaler scaler, 896 AF_Dimension dim ) 897 { 898 FT_Fixed scale; 899 FT_Pos delta; 900 AF_LatinAxis axis; 901 FT_UInt nn; 902 903 904 if ( dim == AF_DIMENSION_HORZ ) 905 { 906 scale = scaler->x_scale; 907 delta = scaler->x_delta; 908 } 909 else 910 { 911 scale = scaler->y_scale; 912 delta = scaler->y_delta; 913 } 914 915 axis = &metrics->axis[dim]; 916 917 if ( axis->org_scale == scale && axis->org_delta == delta ) 918 return; 919 920 axis->org_scale = scale; 921 axis->org_delta = delta; 922 923 /* 924 * correct X and Y scale to optimize the alignment of the top of small 925 * letters to the pixel grid 926 */ 927 { 928 AF_LatinAxis Axis = &metrics->axis[AF_DIMENSION_VERT]; 929 AF_LatinBlue blue = NULL; 930 931 932 for ( nn = 0; nn < Axis->blue_count; nn++ ) 933 { 934 if ( Axis->blues[nn].flags & AF_LATIN_BLUE_ADJUSTMENT ) 935 { 936 blue = &Axis->blues[nn]; 937 break; 938 } 939 } 940 941 if ( blue ) 942 { 943 FT_Pos scaled; 944 FT_Pos threshold; 945 FT_Pos fitted; 946 FT_UInt limit; 947 FT_UInt ppem; 948 949 950 scaled = FT_MulFix( blue->shoot.org, scaler->y_scale ); 951 ppem = metrics->root.scaler.face->size->metrics.x_ppem; 952 limit = metrics->root.globals->increase_x_height; 953 threshold = 40; 954 955 /* if the `increase-x-height' property is active, */ 956 /* we round up much more often */ 957 if ( limit && 958 ppem <= limit && 959 ppem >= AF_PROP_INCREASE_X_HEIGHT_MIN ) 960 threshold = 52; 961 962 fitted = ( scaled + threshold ) & ~63; 963 964 if ( scaled != fitted ) 965 { 966 #if 0 967 if ( dim == AF_DIMENSION_HORZ ) 968 { 969 if ( fitted < scaled ) 970 scale -= scale / 50; /* scale *= 0.98 */ 971 } 972 else 973 #endif 974 if ( dim == AF_DIMENSION_VERT ) 975 { 976 scale = FT_MulDiv( scale, fitted, scaled ); 977 978 FT_TRACE5(( 979 "af_latin_metrics_scale_dim:" 980 " x height alignment (style `%s'):\n" 981 " " 982 " vertical scaling changed from %.4f to %.4f (by %d%%)\n" 983 "\n", 984 af_style_names[metrics->root.style_class->style], 985 axis->org_scale / 65536.0, 986 scale / 65536.0, 987 ( fitted - scaled ) * 100 / scaled )); 988 } 989 } 990 } 991 } 992 993 axis->scale = scale; 994 axis->delta = delta; 995 996 if ( dim == AF_DIMENSION_HORZ ) 997 { 998 metrics->root.scaler.x_scale = scale; 999 metrics->root.scaler.x_delta = delta; 1000 } 1001 else 1002 { 1003 metrics->root.scaler.y_scale = scale; 1004 metrics->root.scaler.y_delta = delta; 1005 } 1006 1007 FT_TRACE5(( "%s widths (style `%s')\n", 1008 dim == AF_DIMENSION_HORZ ? "horizontal" : "vertical", 1009 af_style_names[metrics->root.style_class->style] )); 1010 1011 /* scale the widths */ 1012 for ( nn = 0; nn < axis->width_count; nn++ ) 1013 { 1014 AF_Width width = axis->widths + nn; 1015 1016 1017 width->cur = FT_MulFix( width->org, scale ); 1018 width->fit = width->cur; 1019 1020 FT_TRACE5(( " %d scaled to %.2f\n", 1021 width->org, 1022 width->cur / 64.0 )); 1023 } 1024 1025 FT_TRACE5(( "\n" )); 1026 1027 /* an extra-light axis corresponds to a standard width that is */ 1028 /* smaller than 5/8 pixels */ 1029 axis->extra_light = 1030 (FT_Bool)( FT_MulFix( axis->standard_width, scale ) < 32 + 8 ); 1031 1032 #ifdef FT_DEBUG_LEVEL_TRACE 1033 if ( axis->extra_light ) 1034 FT_TRACE5(( "`%s' style is extra light (at current resolution)\n" 1035 "\n", 1036 af_style_names[metrics->root.style_class->style] )); 1037 #endif 1038 1039 if ( dim == AF_DIMENSION_VERT ) 1040 { 1041 #ifdef FT_DEBUG_LEVEL_TRACE 1042 if ( axis->blue_count ) 1043 FT_TRACE5(( "blue zones (style `%s')\n", 1044 af_style_names[metrics->root.style_class->style] )); 1045 #endif 1046 1047 /* scale the blue zones */ 1048 for ( nn = 0; nn < axis->blue_count; nn++ ) 1049 { 1050 AF_LatinBlue blue = &axis->blues[nn]; 1051 FT_Pos dist; 1052 1053 1054 blue->ref.cur = FT_MulFix( blue->ref.org, scale ) + delta; 1055 blue->ref.fit = blue->ref.cur; 1056 blue->shoot.cur = FT_MulFix( blue->shoot.org, scale ) + delta; 1057 blue->shoot.fit = blue->shoot.cur; 1058 blue->flags &= ~AF_LATIN_BLUE_ACTIVE; 1059 1060 /* a blue zone is only active if it is less than 3/4 pixels tall */ 1061 dist = FT_MulFix( blue->ref.org - blue->shoot.org, scale ); 1062 if ( dist <= 48 && dist >= -48 ) 1063 { 1064 #if 0 1065 FT_Pos delta1; 1066 #endif 1067 FT_Pos delta2; 1068 1069 1070 /* use discrete values for blue zone widths */ 1071 1072 #if 0 1073 1074 /* generic, original code */ 1075 delta1 = blue->shoot.org - blue->ref.org; 1076 delta2 = delta1; 1077 if ( delta1 < 0 ) 1078 delta2 = -delta2; 1079 1080 delta2 = FT_MulFix( delta2, scale ); 1081 1082 if ( delta2 < 32 ) 1083 delta2 = 0; 1084 else if ( delta2 < 64 ) 1085 delta2 = 32 + ( ( ( delta2 - 32 ) + 16 ) & ~31 ); 1086 else 1087 delta2 = FT_PIX_ROUND( delta2 ); 1088 1089 if ( delta1 < 0 ) 1090 delta2 = -delta2; 1091 1092 blue->ref.fit = FT_PIX_ROUND( blue->ref.cur ); 1093 blue->shoot.fit = blue->ref.fit + delta2; 1094 1095 #else 1096 1097 /* simplified version due to abs(dist) <= 48 */ 1098 delta2 = dist; 1099 if ( dist < 0 ) 1100 delta2 = -delta2; 1101 1102 if ( delta2 < 32 ) 1103 delta2 = 0; 1104 else if ( delta2 < 48 ) 1105 delta2 = 32; 1106 else 1107 delta2 = 64; 1108 1109 if ( dist < 0 ) 1110 delta2 = -delta2; 1111 1112 blue->ref.fit = FT_PIX_ROUND( blue->ref.cur ); 1113 blue->shoot.fit = blue->ref.fit - delta2; 1114 1115 #endif 1116 1117 blue->flags |= AF_LATIN_BLUE_ACTIVE; 1118 1119 FT_TRACE5(( " reference %d: %d scaled to %.2f%s\n" 1120 " overshoot %d: %d scaled to %.2f%s\n", 1121 nn, 1122 blue->ref.org, 1123 blue->ref.fit / 64.0, 1124 blue->flags & AF_LATIN_BLUE_ACTIVE ? "" 1125 : " (inactive)", 1126 nn, 1127 blue->shoot.org, 1128 blue->shoot.fit / 64.0, 1129 blue->flags & AF_LATIN_BLUE_ACTIVE ? "" 1130 : " (inactive)" )); 1131 } 1132 } 1133 } 1134 } 1135 1136 1137 /* Scale global values in both directions. */ 1138 1139 FT_LOCAL_DEF( void ) af_latin_metrics_scale(AF_LatinMetrics metrics,AF_Scaler scaler)1140 af_latin_metrics_scale( AF_LatinMetrics metrics, 1141 AF_Scaler scaler ) 1142 { 1143 metrics->root.scaler.render_mode = scaler->render_mode; 1144 metrics->root.scaler.face = scaler->face; 1145 metrics->root.scaler.flags = scaler->flags; 1146 1147 af_latin_metrics_scale_dim( metrics, scaler, AF_DIMENSION_HORZ ); 1148 af_latin_metrics_scale_dim( metrics, scaler, AF_DIMENSION_VERT ); 1149 } 1150 1151 1152 /*************************************************************************/ 1153 /*************************************************************************/ 1154 /***** *****/ 1155 /***** L A T I N G L Y P H A N A L Y S I S *****/ 1156 /***** *****/ 1157 /*************************************************************************/ 1158 /*************************************************************************/ 1159 1160 1161 /* Walk over all contours and compute its segments. */ 1162 1163 FT_LOCAL_DEF( FT_Error ) af_latin_hints_compute_segments(AF_GlyphHints hints,AF_Dimension dim)1164 af_latin_hints_compute_segments( AF_GlyphHints hints, 1165 AF_Dimension dim ) 1166 { 1167 AF_LatinMetrics metrics = (AF_LatinMetrics)hints->metrics; 1168 AF_AxisHints axis = &hints->axis[dim]; 1169 FT_Memory memory = hints->memory; 1170 FT_Error error = FT_Err_Ok; 1171 AF_Segment segment = NULL; 1172 AF_SegmentRec seg0; 1173 AF_Point* contour = hints->contours; 1174 AF_Point* contour_limit = contour + hints->num_contours; 1175 AF_Direction major_dir, segment_dir; 1176 1177 FT_Pos flat_threshold = FLAT_THRESHOLD( metrics->units_per_em ); 1178 1179 1180 FT_ZERO( &seg0 ); 1181 seg0.score = 32000; 1182 seg0.flags = AF_EDGE_NORMAL; 1183 1184 major_dir = (AF_Direction)FT_ABS( axis->major_dir ); 1185 segment_dir = major_dir; 1186 1187 axis->num_segments = 0; 1188 1189 /* set up (u,v) in each point */ 1190 if ( dim == AF_DIMENSION_HORZ ) 1191 { 1192 AF_Point point = hints->points; 1193 AF_Point limit = point + hints->num_points; 1194 1195 1196 for ( ; point < limit; point++ ) 1197 { 1198 point->u = point->fx; 1199 point->v = point->fy; 1200 } 1201 } 1202 else 1203 { 1204 AF_Point point = hints->points; 1205 AF_Point limit = point + hints->num_points; 1206 1207 1208 for ( ; point < limit; point++ ) 1209 { 1210 point->u = point->fy; 1211 point->v = point->fx; 1212 } 1213 } 1214 1215 /* do each contour separately */ 1216 for ( ; contour < contour_limit; contour++ ) 1217 { 1218 AF_Point point = contour[0]; 1219 AF_Point last = point->prev; 1220 int on_edge = 0; 1221 FT_Pos min_pos = 32000; /* minimum segment pos != min_coord */ 1222 FT_Pos max_pos = -32000; /* maximum segment pos != max_coord */ 1223 FT_Pos min_on_pos = 32000; 1224 FT_Pos max_on_pos = -32000; 1225 FT_Bool passed; 1226 1227 1228 if ( point == last ) /* skip singletons -- just in case */ 1229 continue; 1230 1231 if ( FT_ABS( last->out_dir ) == major_dir && 1232 FT_ABS( point->out_dir ) == major_dir ) 1233 { 1234 /* we are already on an edge, try to locate its start */ 1235 last = point; 1236 1237 for (;;) 1238 { 1239 point = point->prev; 1240 if ( FT_ABS( point->out_dir ) != major_dir ) 1241 { 1242 point = point->next; 1243 break; 1244 } 1245 if ( point == last ) 1246 break; 1247 } 1248 } 1249 1250 last = point; 1251 passed = 0; 1252 1253 for (;;) 1254 { 1255 FT_Pos u, v; 1256 1257 1258 if ( on_edge ) 1259 { 1260 u = point->u; 1261 if ( u < min_pos ) 1262 min_pos = u; 1263 if ( u > max_pos ) 1264 max_pos = u; 1265 1266 /* get minimum and maximum coordinate of on points */ 1267 if ( !( point->flags & AF_FLAG_CONTROL ) ) 1268 { 1269 v = point->v; 1270 if ( v < min_on_pos ) 1271 min_on_pos = v; 1272 if ( v > max_on_pos ) 1273 max_on_pos = v; 1274 } 1275 1276 if ( point->out_dir != segment_dir || point == last ) 1277 { 1278 /* we are just leaving an edge; record a new segment! */ 1279 segment->last = point; 1280 segment->pos = (FT_Short)( ( min_pos + max_pos ) >> 1 ); 1281 1282 /* a segment is round if either its first or last point */ 1283 /* is a control point, and the length of the on points */ 1284 /* inbetween doesn't exceed a heuristic limit */ 1285 if ( ( segment->first->flags | point->flags ) & AF_FLAG_CONTROL && 1286 ( max_on_pos - min_on_pos ) < flat_threshold ) 1287 segment->flags |= AF_EDGE_ROUND; 1288 1289 /* compute segment size */ 1290 min_pos = max_pos = point->v; 1291 1292 v = segment->first->v; 1293 if ( v < min_pos ) 1294 min_pos = v; 1295 if ( v > max_pos ) 1296 max_pos = v; 1297 1298 segment->min_coord = (FT_Short)min_pos; 1299 segment->max_coord = (FT_Short)max_pos; 1300 segment->height = (FT_Short)( segment->max_coord - 1301 segment->min_coord ); 1302 1303 on_edge = 0; 1304 segment = NULL; 1305 /* fall through */ 1306 } 1307 } 1308 1309 /* now exit if we are at the start/end point */ 1310 if ( point == last ) 1311 { 1312 if ( passed ) 1313 break; 1314 passed = 1; 1315 } 1316 1317 if ( !on_edge && FT_ABS( point->out_dir ) == major_dir ) 1318 { 1319 /* this is the start of a new segment! */ 1320 segment_dir = (AF_Direction)point->out_dir; 1321 1322 error = af_axis_hints_new_segment( axis, memory, &segment ); 1323 if ( error ) 1324 goto Exit; 1325 1326 /* clear all segment fields */ 1327 segment[0] = seg0; 1328 1329 segment->dir = (FT_Char)segment_dir; 1330 segment->first = point; 1331 segment->last = point; 1332 1333 min_pos = max_pos = point->u; 1334 1335 if ( point->flags & AF_FLAG_CONTROL ) 1336 { 1337 min_on_pos = 32000; 1338 max_on_pos = -32000; 1339 } 1340 else 1341 min_on_pos = max_on_pos = point->v; 1342 1343 on_edge = 1; 1344 } 1345 1346 point = point->next; 1347 } 1348 1349 } /* contours */ 1350 1351 1352 /* now slightly increase the height of segments if this makes */ 1353 /* sense -- this is used to better detect and ignore serifs */ 1354 { 1355 AF_Segment segments = axis->segments; 1356 AF_Segment segments_end = segments + axis->num_segments; 1357 1358 1359 for ( segment = segments; segment < segments_end; segment++ ) 1360 { 1361 AF_Point first = segment->first; 1362 AF_Point last = segment->last; 1363 FT_Pos first_v = first->v; 1364 FT_Pos last_v = last->v; 1365 1366 1367 if ( first_v < last_v ) 1368 { 1369 AF_Point p; 1370 1371 1372 p = first->prev; 1373 if ( p->v < first_v ) 1374 segment->height = (FT_Short)( segment->height + 1375 ( ( first_v - p->v ) >> 1 ) ); 1376 1377 p = last->next; 1378 if ( p->v > last_v ) 1379 segment->height = (FT_Short)( segment->height + 1380 ( ( p->v - last_v ) >> 1 ) ); 1381 } 1382 else 1383 { 1384 AF_Point p; 1385 1386 1387 p = first->prev; 1388 if ( p->v > first_v ) 1389 segment->height = (FT_Short)( segment->height + 1390 ( ( p->v - first_v ) >> 1 ) ); 1391 1392 p = last->next; 1393 if ( p->v < last_v ) 1394 segment->height = (FT_Short)( segment->height + 1395 ( ( last_v - p->v ) >> 1 ) ); 1396 } 1397 } 1398 } 1399 1400 Exit: 1401 return error; 1402 } 1403 1404 1405 /* Link segments to form stems and serifs. If `width_count' and */ 1406 /* `widths' are non-zero, use them to fine-tune the scoring function. */ 1407 1408 FT_LOCAL_DEF( void ) af_latin_hints_link_segments(AF_GlyphHints hints,FT_UInt width_count,AF_WidthRec * widths,AF_Dimension dim)1409 af_latin_hints_link_segments( AF_GlyphHints hints, 1410 FT_UInt width_count, 1411 AF_WidthRec* widths, 1412 AF_Dimension dim ) 1413 { 1414 AF_AxisHints axis = &hints->axis[dim]; 1415 AF_Segment segments = axis->segments; 1416 AF_Segment segment_limit = segments + axis->num_segments; 1417 FT_Pos len_threshold, len_score, dist_score, max_width; 1418 AF_Segment seg1, seg2; 1419 1420 1421 if ( width_count ) 1422 max_width = widths[width_count - 1].org; 1423 else 1424 max_width = 0; 1425 1426 /* a heuristic value to set up a minimum value for overlapping */ 1427 len_threshold = AF_LATIN_CONSTANT( hints->metrics, 8 ); 1428 if ( len_threshold == 0 ) 1429 len_threshold = 1; 1430 1431 /* a heuristic value to weight lengths */ 1432 len_score = AF_LATIN_CONSTANT( hints->metrics, 6000 ); 1433 1434 /* a heuristic value to weight distances (no call to */ 1435 /* AF_LATIN_CONSTANT needed, since we work on multiples */ 1436 /* of the stem width) */ 1437 dist_score = 3000; 1438 1439 /* now compare each segment to the others */ 1440 for ( seg1 = segments; seg1 < segment_limit; seg1++ ) 1441 { 1442 if ( seg1->dir != axis->major_dir ) 1443 continue; 1444 1445 /* search for stems having opposite directions, */ 1446 /* with seg1 to the `left' of seg2 */ 1447 for ( seg2 = segments; seg2 < segment_limit; seg2++ ) 1448 { 1449 FT_Pos pos1 = seg1->pos; 1450 FT_Pos pos2 = seg2->pos; 1451 1452 1453 if ( seg1->dir + seg2->dir == 0 && pos2 > pos1 ) 1454 { 1455 /* compute distance between the two segments */ 1456 FT_Pos min = seg1->min_coord; 1457 FT_Pos max = seg1->max_coord; 1458 FT_Pos len; 1459 1460 1461 if ( min < seg2->min_coord ) 1462 min = seg2->min_coord; 1463 1464 if ( max > seg2->max_coord ) 1465 max = seg2->max_coord; 1466 1467 /* compute maximum coordinate difference of the two segments */ 1468 /* (this is, how much they overlap) */ 1469 len = max - min; 1470 if ( len >= len_threshold ) 1471 { 1472 /* 1473 * The score is the sum of two demerits indicating the 1474 * `badness' of a fit, measured along the segments' main axis 1475 * and orthogonal to it, respectively. 1476 * 1477 * o The less overlapping along the main axis, the worse it 1478 * is, causing a larger demerit. 1479 * 1480 * o The nearer the orthogonal distance to a stem width, the 1481 * better it is, causing a smaller demerit. For simplicity, 1482 * however, we only increase the demerit for values that 1483 * exceed the largest stem width. 1484 */ 1485 1486 FT_Pos dist = pos2 - pos1; 1487 1488 FT_Pos dist_demerit, score; 1489 1490 1491 if ( max_width ) 1492 { 1493 /* distance demerits are based on multiples of `max_width'; */ 1494 /* we scale by 1024 for getting more precision */ 1495 FT_Pos delta = ( dist << 10 ) / max_width - ( 1 << 10 ); 1496 1497 1498 if ( delta > 10000 ) 1499 dist_demerit = 32000; 1500 else if ( delta > 0 ) 1501 dist_demerit = delta * delta / dist_score; 1502 else 1503 dist_demerit = 0; 1504 } 1505 else 1506 dist_demerit = dist; /* default if no widths available */ 1507 1508 score = dist_demerit + len_score / len; 1509 1510 /* and we search for the smallest score */ 1511 if ( score < seg1->score ) 1512 { 1513 seg1->score = score; 1514 seg1->link = seg2; 1515 } 1516 1517 if ( score < seg2->score ) 1518 { 1519 seg2->score = score; 1520 seg2->link = seg1; 1521 } 1522 } 1523 } 1524 } 1525 } 1526 1527 /* now compute the `serif' segments, cf. explanations in `afhints.h' */ 1528 for ( seg1 = segments; seg1 < segment_limit; seg1++ ) 1529 { 1530 seg2 = seg1->link; 1531 1532 if ( seg2 ) 1533 { 1534 if ( seg2->link != seg1 ) 1535 { 1536 seg1->link = 0; 1537 seg1->serif = seg2->link; 1538 } 1539 } 1540 } 1541 } 1542 1543 1544 /* Link segments to edges, using feature analysis for selection. */ 1545 1546 FT_LOCAL_DEF( FT_Error ) af_latin_hints_compute_edges(AF_GlyphHints hints,AF_Dimension dim)1547 af_latin_hints_compute_edges( AF_GlyphHints hints, 1548 AF_Dimension dim ) 1549 { 1550 AF_AxisHints axis = &hints->axis[dim]; 1551 FT_Error error = FT_Err_Ok; 1552 FT_Memory memory = hints->memory; 1553 AF_LatinAxis laxis = &((AF_LatinMetrics)hints->metrics)->axis[dim]; 1554 1555 AF_Segment segments = axis->segments; 1556 AF_Segment segment_limit = segments + axis->num_segments; 1557 AF_Segment seg; 1558 1559 #if 0 1560 AF_Direction up_dir; 1561 #endif 1562 FT_Fixed scale; 1563 FT_Pos edge_distance_threshold; 1564 FT_Pos segment_length_threshold; 1565 1566 1567 axis->num_edges = 0; 1568 1569 scale = ( dim == AF_DIMENSION_HORZ ) ? hints->x_scale 1570 : hints->y_scale; 1571 1572 #if 0 1573 up_dir = ( dim == AF_DIMENSION_HORZ ) ? AF_DIR_UP 1574 : AF_DIR_RIGHT; 1575 #endif 1576 1577 /* 1578 * We ignore all segments that are less than 1 pixel in length 1579 * to avoid many problems with serif fonts. We compute the 1580 * corresponding threshold in font units. 1581 */ 1582 if ( dim == AF_DIMENSION_HORZ ) 1583 segment_length_threshold = FT_DivFix( 64, hints->y_scale ); 1584 else 1585 segment_length_threshold = 0; 1586 1587 /*********************************************************************/ 1588 /* */ 1589 /* We begin by generating a sorted table of edges for the current */ 1590 /* direction. To do so, we simply scan each segment and try to find */ 1591 /* an edge in our table that corresponds to its position. */ 1592 /* */ 1593 /* If no edge is found, we create and insert a new edge in the */ 1594 /* sorted table. Otherwise, we simply add the segment to the edge's */ 1595 /* list which gets processed in the second step to compute the */ 1596 /* edge's properties. */ 1597 /* */ 1598 /* Note that the table of edges is sorted along the segment/edge */ 1599 /* position. */ 1600 /* */ 1601 /*********************************************************************/ 1602 1603 /* assure that edge distance threshold is at most 0.25px */ 1604 edge_distance_threshold = FT_MulFix( laxis->edge_distance_threshold, 1605 scale ); 1606 if ( edge_distance_threshold > 64 / 4 ) 1607 edge_distance_threshold = 64 / 4; 1608 1609 edge_distance_threshold = FT_DivFix( edge_distance_threshold, 1610 scale ); 1611 1612 for ( seg = segments; seg < segment_limit; seg++ ) 1613 { 1614 AF_Edge found = NULL; 1615 FT_Int ee; 1616 1617 1618 if ( seg->height < segment_length_threshold ) 1619 continue; 1620 1621 /* A special case for serif edges: If they are smaller than */ 1622 /* 1.5 pixels we ignore them. */ 1623 if ( seg->serif && 1624 2 * seg->height < 3 * segment_length_threshold ) 1625 continue; 1626 1627 /* look for an edge corresponding to the segment */ 1628 for ( ee = 0; ee < axis->num_edges; ee++ ) 1629 { 1630 AF_Edge edge = axis->edges + ee; 1631 FT_Pos dist; 1632 1633 1634 dist = seg->pos - edge->fpos; 1635 if ( dist < 0 ) 1636 dist = -dist; 1637 1638 if ( dist < edge_distance_threshold && edge->dir == seg->dir ) 1639 { 1640 found = edge; 1641 break; 1642 } 1643 } 1644 1645 if ( !found ) 1646 { 1647 AF_Edge edge; 1648 1649 1650 /* insert a new edge in the list and */ 1651 /* sort according to the position */ 1652 error = af_axis_hints_new_edge( axis, seg->pos, 1653 (AF_Direction)seg->dir, 1654 memory, &edge ); 1655 if ( error ) 1656 goto Exit; 1657 1658 /* add the segment to the new edge's list */ 1659 FT_ZERO( edge ); 1660 1661 edge->first = seg; 1662 edge->last = seg; 1663 edge->dir = seg->dir; 1664 edge->fpos = seg->pos; 1665 edge->opos = FT_MulFix( seg->pos, scale ); 1666 edge->pos = edge->opos; 1667 seg->edge_next = seg; 1668 } 1669 else 1670 { 1671 /* if an edge was found, simply add the segment to the edge's */ 1672 /* list */ 1673 seg->edge_next = found->first; 1674 found->last->edge_next = seg; 1675 found->last = seg; 1676 } 1677 } 1678 1679 1680 /******************************************************************/ 1681 /* */ 1682 /* Good, we now compute each edge's properties according to the */ 1683 /* segments found on its position. Basically, these are */ 1684 /* */ 1685 /* - the edge's main direction */ 1686 /* - stem edge, serif edge or both (which defaults to stem then) */ 1687 /* - rounded edge, straight or both (which defaults to straight) */ 1688 /* - link for edge */ 1689 /* */ 1690 /******************************************************************/ 1691 1692 /* first of all, set the `edge' field in each segment -- this is */ 1693 /* required in order to compute edge links */ 1694 1695 /* 1696 * Note that removing this loop and setting the `edge' field of each 1697 * segment directly in the code above slows down execution speed for 1698 * some reasons on platforms like the Sun. 1699 */ 1700 { 1701 AF_Edge edges = axis->edges; 1702 AF_Edge edge_limit = edges + axis->num_edges; 1703 AF_Edge edge; 1704 1705 1706 for ( edge = edges; edge < edge_limit; edge++ ) 1707 { 1708 seg = edge->first; 1709 if ( seg ) 1710 do 1711 { 1712 seg->edge = edge; 1713 seg = seg->edge_next; 1714 1715 } while ( seg != edge->first ); 1716 } 1717 1718 /* now compute each edge properties */ 1719 for ( edge = edges; edge < edge_limit; edge++ ) 1720 { 1721 FT_Int is_round = 0; /* does it contain round segments? */ 1722 FT_Int is_straight = 0; /* does it contain straight segments? */ 1723 #if 0 1724 FT_Pos ups = 0; /* number of upwards segments */ 1725 FT_Pos downs = 0; /* number of downwards segments */ 1726 #endif 1727 1728 1729 seg = edge->first; 1730 1731 do 1732 { 1733 FT_Bool is_serif; 1734 1735 1736 /* check for roundness of segment */ 1737 if ( seg->flags & AF_EDGE_ROUND ) 1738 is_round++; 1739 else 1740 is_straight++; 1741 1742 #if 0 1743 /* check for segment direction */ 1744 if ( seg->dir == up_dir ) 1745 ups += seg->max_coord - seg->min_coord; 1746 else 1747 downs += seg->max_coord - seg->min_coord; 1748 #endif 1749 1750 /* check for links -- if seg->serif is set, then seg->link must */ 1751 /* be ignored */ 1752 is_serif = (FT_Bool)( seg->serif && 1753 seg->serif->edge && 1754 seg->serif->edge != edge ); 1755 1756 if ( ( seg->link && seg->link->edge != NULL ) || is_serif ) 1757 { 1758 AF_Edge edge2; 1759 AF_Segment seg2; 1760 1761 1762 edge2 = edge->link; 1763 seg2 = seg->link; 1764 1765 if ( is_serif ) 1766 { 1767 seg2 = seg->serif; 1768 edge2 = edge->serif; 1769 } 1770 1771 if ( edge2 ) 1772 { 1773 FT_Pos edge_delta; 1774 FT_Pos seg_delta; 1775 1776 1777 edge_delta = edge->fpos - edge2->fpos; 1778 if ( edge_delta < 0 ) 1779 edge_delta = -edge_delta; 1780 1781 seg_delta = seg->pos - seg2->pos; 1782 if ( seg_delta < 0 ) 1783 seg_delta = -seg_delta; 1784 1785 if ( seg_delta < edge_delta ) 1786 edge2 = seg2->edge; 1787 } 1788 else 1789 edge2 = seg2->edge; 1790 1791 if ( is_serif ) 1792 { 1793 edge->serif = edge2; 1794 edge2->flags |= AF_EDGE_SERIF; 1795 } 1796 else 1797 edge->link = edge2; 1798 } 1799 1800 seg = seg->edge_next; 1801 1802 } while ( seg != edge->first ); 1803 1804 /* set the round/straight flags */ 1805 edge->flags = AF_EDGE_NORMAL; 1806 1807 if ( is_round > 0 && is_round >= is_straight ) 1808 edge->flags |= AF_EDGE_ROUND; 1809 1810 #if 0 1811 /* set the edge's main direction */ 1812 edge->dir = AF_DIR_NONE; 1813 1814 if ( ups > downs ) 1815 edge->dir = (FT_Char)up_dir; 1816 1817 else if ( ups < downs ) 1818 edge->dir = (FT_Char)-up_dir; 1819 1820 else if ( ups == downs ) 1821 edge->dir = 0; /* both up and down! */ 1822 #endif 1823 1824 /* get rid of serifs if link is set */ 1825 /* XXX: This gets rid of many unpleasant artefacts! */ 1826 /* Example: the `c' in cour.pfa at size 13 */ 1827 1828 if ( edge->serif && edge->link ) 1829 edge->serif = NULL; 1830 } 1831 } 1832 1833 Exit: 1834 return error; 1835 } 1836 1837 1838 /* Detect segments and edges for given dimension. */ 1839 1840 FT_LOCAL_DEF( FT_Error ) af_latin_hints_detect_features(AF_GlyphHints hints,FT_UInt width_count,AF_WidthRec * widths,AF_Dimension dim)1841 af_latin_hints_detect_features( AF_GlyphHints hints, 1842 FT_UInt width_count, 1843 AF_WidthRec* widths, 1844 AF_Dimension dim ) 1845 { 1846 FT_Error error; 1847 1848 1849 error = af_latin_hints_compute_segments( hints, dim ); 1850 if ( !error ) 1851 { 1852 af_latin_hints_link_segments( hints, width_count, widths, dim ); 1853 1854 error = af_latin_hints_compute_edges( hints, dim ); 1855 } 1856 1857 return error; 1858 } 1859 1860 1861 /* Compute all edges which lie within blue zones. */ 1862 1863 static void af_latin_hints_compute_blue_edges(AF_GlyphHints hints,AF_LatinMetrics metrics)1864 af_latin_hints_compute_blue_edges( AF_GlyphHints hints, 1865 AF_LatinMetrics metrics ) 1866 { 1867 AF_AxisHints axis = &hints->axis[AF_DIMENSION_VERT]; 1868 AF_Edge edge = axis->edges; 1869 AF_Edge edge_limit = edge + axis->num_edges; 1870 AF_LatinAxis latin = &metrics->axis[AF_DIMENSION_VERT]; 1871 FT_Fixed scale = latin->scale; 1872 1873 1874 /* compute which blue zones are active, i.e. have their scaled */ 1875 /* size < 3/4 pixels */ 1876 1877 /* for each horizontal edge search the blue zone which is closest */ 1878 for ( ; edge < edge_limit; edge++ ) 1879 { 1880 FT_UInt bb; 1881 AF_Width best_blue = NULL; 1882 FT_Bool best_blue_is_neutral = 0; 1883 FT_Pos best_dist; /* initial threshold */ 1884 1885 1886 /* compute the initial threshold as a fraction of the EM size */ 1887 /* (the value 40 is heuristic) */ 1888 best_dist = FT_MulFix( metrics->units_per_em / 40, scale ); 1889 1890 /* assure a minimum distance of 0.5px */ 1891 if ( best_dist > 64 / 2 ) 1892 best_dist = 64 / 2; 1893 1894 for ( bb = 0; bb < latin->blue_count; bb++ ) 1895 { 1896 AF_LatinBlue blue = latin->blues + bb; 1897 FT_Bool is_top_blue, is_neutral_blue, is_major_dir; 1898 1899 1900 /* skip inactive blue zones (i.e., those that are too large) */ 1901 if ( !( blue->flags & AF_LATIN_BLUE_ACTIVE ) ) 1902 continue; 1903 1904 /* if it is a top zone, check for right edges (against the major */ 1905 /* direction); if it is a bottom zone, check for left edges (in */ 1906 /* the major direction) -- this assumes the TrueType convention */ 1907 /* for the orientation of contours */ 1908 is_top_blue = 1909 (FT_Byte)( ( blue->flags & AF_LATIN_BLUE_TOP ) != 0 ); 1910 is_neutral_blue = 1911 (FT_Byte)( ( blue->flags & AF_LATIN_BLUE_NEUTRAL ) != 0); 1912 is_major_dir = 1913 FT_BOOL( edge->dir == axis->major_dir ); 1914 1915 /* neutral blue zones are handled for both directions */ 1916 if ( is_top_blue ^ is_major_dir || is_neutral_blue ) 1917 { 1918 FT_Pos dist; 1919 1920 1921 /* first of all, compare it to the reference position */ 1922 dist = edge->fpos - blue->ref.org; 1923 if ( dist < 0 ) 1924 dist = -dist; 1925 1926 dist = FT_MulFix( dist, scale ); 1927 if ( dist < best_dist ) 1928 { 1929 best_dist = dist; 1930 best_blue = &blue->ref; 1931 best_blue_is_neutral = is_neutral_blue; 1932 } 1933 1934 /* now compare it to the overshoot position and check whether */ 1935 /* the edge is rounded, and whether the edge is over the */ 1936 /* reference position of a top zone, or under the reference */ 1937 /* position of a bottom zone (provided we don't have a */ 1938 /* neutral blue zone) */ 1939 if ( edge->flags & AF_EDGE_ROUND && 1940 dist != 0 && 1941 !is_neutral_blue ) 1942 { 1943 FT_Bool is_under_ref = FT_BOOL( edge->fpos < blue->ref.org ); 1944 1945 1946 if ( is_top_blue ^ is_under_ref ) 1947 { 1948 dist = edge->fpos - blue->shoot.org; 1949 if ( dist < 0 ) 1950 dist = -dist; 1951 1952 dist = FT_MulFix( dist, scale ); 1953 if ( dist < best_dist ) 1954 { 1955 best_dist = dist; 1956 best_blue = &blue->shoot; 1957 best_blue_is_neutral = is_neutral_blue; 1958 } 1959 } 1960 } 1961 } 1962 } 1963 1964 if ( best_blue ) 1965 { 1966 edge->blue_edge = best_blue; 1967 if ( best_blue_is_neutral ) 1968 edge->flags |= AF_EDGE_NEUTRAL; 1969 } 1970 } 1971 } 1972 1973 1974 /* Initalize hinting engine. */ 1975 1976 static FT_Error af_latin_hints_init(AF_GlyphHints hints,AF_LatinMetrics metrics)1977 af_latin_hints_init( AF_GlyphHints hints, 1978 AF_LatinMetrics metrics ) 1979 { 1980 FT_Render_Mode mode; 1981 FT_UInt32 scaler_flags, other_flags; 1982 FT_Face face = metrics->root.scaler.face; 1983 1984 1985 af_glyph_hints_rescale( hints, (AF_StyleMetrics)metrics ); 1986 1987 /* 1988 * correct x_scale and y_scale if needed, since they may have 1989 * been modified by `af_latin_metrics_scale_dim' above 1990 */ 1991 hints->x_scale = metrics->axis[AF_DIMENSION_HORZ].scale; 1992 hints->x_delta = metrics->axis[AF_DIMENSION_HORZ].delta; 1993 hints->y_scale = metrics->axis[AF_DIMENSION_VERT].scale; 1994 hints->y_delta = metrics->axis[AF_DIMENSION_VERT].delta; 1995 1996 /* compute flags depending on render mode, etc. */ 1997 mode = metrics->root.scaler.render_mode; 1998 1999 #if 0 /* #ifdef AF_CONFIG_OPTION_USE_WARPER */ 2000 if ( mode == FT_RENDER_MODE_LCD || mode == FT_RENDER_MODE_LCD_V ) 2001 metrics->root.scaler.render_mode = mode = FT_RENDER_MODE_NORMAL; 2002 #endif 2003 2004 scaler_flags = hints->scaler_flags; 2005 other_flags = 0; 2006 2007 /* 2008 * We snap the width of vertical stems for the monochrome and 2009 * horizontal LCD rendering targets only. 2010 */ 2011 if ( mode == FT_RENDER_MODE_MONO || mode == FT_RENDER_MODE_LCD ) 2012 other_flags |= AF_LATIN_HINTS_HORZ_SNAP; 2013 2014 /* 2015 * We snap the width of horizontal stems for the monochrome and 2016 * vertical LCD rendering targets only. 2017 */ 2018 if ( mode == FT_RENDER_MODE_MONO || mode == FT_RENDER_MODE_LCD_V ) 2019 other_flags |= AF_LATIN_HINTS_VERT_SNAP; 2020 2021 /* 2022 * We adjust stems to full pixels only if we don't use the `light' mode. 2023 */ 2024 if ( mode != FT_RENDER_MODE_LIGHT ) 2025 other_flags |= AF_LATIN_HINTS_STEM_ADJUST; 2026 2027 if ( mode == FT_RENDER_MODE_MONO ) 2028 other_flags |= AF_LATIN_HINTS_MONO; 2029 2030 /* 2031 * In `light' hinting mode we disable horizontal hinting completely. 2032 * We also do it if the face is italic. 2033 * 2034 * However, if warping is enabled (which only works in `light' hinting 2035 * mode), advance widths get adjusted, too. 2036 */ 2037 if ( mode == FT_RENDER_MODE_LIGHT || 2038 ( face->style_flags & FT_STYLE_FLAG_ITALIC ) != 0 ) 2039 scaler_flags |= AF_SCALER_FLAG_NO_HORIZONTAL; 2040 2041 #ifdef AF_CONFIG_OPTION_USE_WARPER 2042 /* get (global) warper flag */ 2043 if ( !metrics->root.globals->module->warping ) 2044 scaler_flags |= AF_SCALER_FLAG_NO_WARPER; 2045 #endif 2046 2047 hints->scaler_flags = scaler_flags; 2048 hints->other_flags = other_flags; 2049 2050 return FT_Err_Ok; 2051 } 2052 2053 2054 /*************************************************************************/ 2055 /*************************************************************************/ 2056 /***** *****/ 2057 /***** L A T I N G L Y P H G R I D - F I T T I N G *****/ 2058 /***** *****/ 2059 /*************************************************************************/ 2060 /*************************************************************************/ 2061 2062 /* Snap a given width in scaled coordinates to one of the */ 2063 /* current standard widths. */ 2064 2065 static FT_Pos af_latin_snap_width(AF_Width widths,FT_UInt count,FT_Pos width)2066 af_latin_snap_width( AF_Width widths, 2067 FT_UInt count, 2068 FT_Pos width ) 2069 { 2070 FT_UInt n; 2071 FT_Pos best = 64 + 32 + 2; 2072 FT_Pos reference = width; 2073 FT_Pos scaled; 2074 2075 2076 for ( n = 0; n < count; n++ ) 2077 { 2078 FT_Pos w; 2079 FT_Pos dist; 2080 2081 2082 w = widths[n].cur; 2083 dist = width - w; 2084 if ( dist < 0 ) 2085 dist = -dist; 2086 if ( dist < best ) 2087 { 2088 best = dist; 2089 reference = w; 2090 } 2091 } 2092 2093 scaled = FT_PIX_ROUND( reference ); 2094 2095 if ( width >= reference ) 2096 { 2097 if ( width < scaled + 48 ) 2098 width = reference; 2099 } 2100 else 2101 { 2102 if ( width > scaled - 48 ) 2103 width = reference; 2104 } 2105 2106 return width; 2107 } 2108 2109 2110 /* Compute the snapped width of a given stem, ignoring very thin ones. */ 2111 /* There is a lot of voodoo in this function; changing the hard-coded */ 2112 /* parameters influence the whole hinting process. */ 2113 2114 static FT_Pos af_latin_compute_stem_width(AF_GlyphHints hints,AF_Dimension dim,FT_Pos width,FT_UInt base_flags,FT_UInt stem_flags)2115 af_latin_compute_stem_width( AF_GlyphHints hints, 2116 AF_Dimension dim, 2117 FT_Pos width, 2118 FT_UInt base_flags, 2119 FT_UInt stem_flags ) 2120 { 2121 AF_LatinMetrics metrics = (AF_LatinMetrics)hints->metrics; 2122 AF_LatinAxis axis = &metrics->axis[dim]; 2123 FT_Pos dist = width; 2124 FT_Int sign = 0; 2125 FT_Int vertical = ( dim == AF_DIMENSION_VERT ); 2126 2127 2128 if ( !AF_LATIN_HINTS_DO_STEM_ADJUST( hints ) || 2129 axis->extra_light ) 2130 return width; 2131 2132 if ( dist < 0 ) 2133 { 2134 dist = -width; 2135 sign = 1; 2136 } 2137 2138 if ( ( vertical && !AF_LATIN_HINTS_DO_VERT_SNAP( hints ) ) || 2139 ( !vertical && !AF_LATIN_HINTS_DO_HORZ_SNAP( hints ) ) ) 2140 { 2141 /* smooth hinting process: very lightly quantize the stem width */ 2142 2143 /* leave the widths of serifs alone */ 2144 if ( ( stem_flags & AF_EDGE_SERIF ) && 2145 vertical && 2146 ( dist < 3 * 64 ) ) 2147 goto Done_Width; 2148 2149 else if ( base_flags & AF_EDGE_ROUND ) 2150 { 2151 if ( dist < 80 ) 2152 dist = 64; 2153 } 2154 else if ( dist < 56 ) 2155 dist = 56; 2156 2157 if ( axis->width_count > 0 ) 2158 { 2159 FT_Pos delta; 2160 2161 2162 /* compare to standard width */ 2163 delta = dist - axis->widths[0].cur; 2164 2165 if ( delta < 0 ) 2166 delta = -delta; 2167 2168 if ( delta < 40 ) 2169 { 2170 dist = axis->widths[0].cur; 2171 if ( dist < 48 ) 2172 dist = 48; 2173 2174 goto Done_Width; 2175 } 2176 2177 if ( dist < 3 * 64 ) 2178 { 2179 delta = dist & 63; 2180 dist &= -64; 2181 2182 if ( delta < 10 ) 2183 dist += delta; 2184 2185 else if ( delta < 32 ) 2186 dist += 10; 2187 2188 else if ( delta < 54 ) 2189 dist += 54; 2190 2191 else 2192 dist += delta; 2193 } 2194 else 2195 dist = ( dist + 32 ) & ~63; 2196 } 2197 } 2198 else 2199 { 2200 /* strong hinting process: snap the stem width to integer pixels */ 2201 2202 FT_Pos org_dist = dist; 2203 2204 2205 dist = af_latin_snap_width( axis->widths, axis->width_count, dist ); 2206 2207 if ( vertical ) 2208 { 2209 /* in the case of vertical hinting, always round */ 2210 /* the stem heights to integer pixels */ 2211 2212 if ( dist >= 64 ) 2213 dist = ( dist + 16 ) & ~63; 2214 else 2215 dist = 64; 2216 } 2217 else 2218 { 2219 if ( AF_LATIN_HINTS_DO_MONO( hints ) ) 2220 { 2221 /* monochrome horizontal hinting: snap widths to integer pixels */ 2222 /* with a different threshold */ 2223 2224 if ( dist < 64 ) 2225 dist = 64; 2226 else 2227 dist = ( dist + 32 ) & ~63; 2228 } 2229 else 2230 { 2231 /* for horizontal anti-aliased hinting, we adopt a more subtle */ 2232 /* approach: we strengthen small stems, round stems whose size */ 2233 /* is between 1 and 2 pixels to an integer, otherwise nothing */ 2234 2235 if ( dist < 48 ) 2236 dist = ( dist + 64 ) >> 1; 2237 2238 else if ( dist < 128 ) 2239 { 2240 /* We only round to an integer width if the corresponding */ 2241 /* distortion is less than 1/4 pixel. Otherwise this */ 2242 /* makes everything worse since the diagonals, which are */ 2243 /* not hinted, appear a lot bolder or thinner than the */ 2244 /* vertical stems. */ 2245 2246 FT_Pos delta; 2247 2248 2249 dist = ( dist + 22 ) & ~63; 2250 delta = dist - org_dist; 2251 if ( delta < 0 ) 2252 delta = -delta; 2253 2254 if ( delta >= 16 ) 2255 { 2256 dist = org_dist; 2257 if ( dist < 48 ) 2258 dist = ( dist + 64 ) >> 1; 2259 } 2260 } 2261 else 2262 /* round otherwise to prevent color fringes in LCD mode */ 2263 dist = ( dist + 32 ) & ~63; 2264 } 2265 } 2266 } 2267 2268 Done_Width: 2269 if ( sign ) 2270 dist = -dist; 2271 2272 return dist; 2273 } 2274 2275 2276 /* Align one stem edge relative to the previous stem edge. */ 2277 2278 static void af_latin_align_linked_edge(AF_GlyphHints hints,AF_Dimension dim,AF_Edge base_edge,AF_Edge stem_edge)2279 af_latin_align_linked_edge( AF_GlyphHints hints, 2280 AF_Dimension dim, 2281 AF_Edge base_edge, 2282 AF_Edge stem_edge ) 2283 { 2284 FT_Pos dist = stem_edge->opos - base_edge->opos; 2285 2286 FT_Pos fitted_width = af_latin_compute_stem_width( hints, dim, dist, 2287 base_edge->flags, 2288 stem_edge->flags ); 2289 2290 2291 stem_edge->pos = base_edge->pos + fitted_width; 2292 2293 FT_TRACE5(( " LINK: edge %d (opos=%.2f) linked to %.2f," 2294 " dist was %.2f, now %.2f\n", 2295 stem_edge - hints->axis[dim].edges, stem_edge->opos / 64.0, 2296 stem_edge->pos / 64.0, dist / 64.0, fitted_width / 64.0 )); 2297 } 2298 2299 2300 /* Shift the coordinates of the `serif' edge by the same amount */ 2301 /* as the corresponding `base' edge has been moved already. */ 2302 2303 static void af_latin_align_serif_edge(AF_GlyphHints hints,AF_Edge base,AF_Edge serif)2304 af_latin_align_serif_edge( AF_GlyphHints hints, 2305 AF_Edge base, 2306 AF_Edge serif ) 2307 { 2308 FT_UNUSED( hints ); 2309 2310 serif->pos = base->pos + ( serif->opos - base->opos ); 2311 } 2312 2313 2314 /*************************************************************************/ 2315 /*************************************************************************/ 2316 /*************************************************************************/ 2317 /**** ****/ 2318 /**** E D G E H I N T I N G ****/ 2319 /**** ****/ 2320 /*************************************************************************/ 2321 /*************************************************************************/ 2322 /*************************************************************************/ 2323 2324 2325 /* The main grid-fitting routine. */ 2326 2327 static void af_latin_hint_edges(AF_GlyphHints hints,AF_Dimension dim)2328 af_latin_hint_edges( AF_GlyphHints hints, 2329 AF_Dimension dim ) 2330 { 2331 AF_AxisHints axis = &hints->axis[dim]; 2332 AF_Edge edges = axis->edges; 2333 AF_Edge edge_limit = edges + axis->num_edges; 2334 FT_PtrDist n_edges; 2335 AF_Edge edge; 2336 AF_Edge anchor = NULL; 2337 FT_Int has_serifs = 0; 2338 2339 #ifdef FT_DEBUG_LEVEL_TRACE 2340 FT_UInt num_actions = 0; 2341 #endif 2342 2343 2344 FT_TRACE5(( "latin %s edge hinting (style `%s')\n", 2345 dim == AF_DIMENSION_VERT ? "horizontal" : "vertical", 2346 af_style_names[hints->metrics->style_class->style] )); 2347 2348 /* we begin by aligning all stems relative to the blue zone */ 2349 /* if needed -- that's only for horizontal edges */ 2350 2351 if ( dim == AF_DIMENSION_VERT && AF_HINTS_DO_BLUES( hints ) ) 2352 { 2353 for ( edge = edges; edge < edge_limit; edge++ ) 2354 { 2355 AF_Width blue; 2356 AF_Edge edge1, edge2; /* these edges form the stem to check */ 2357 2358 2359 if ( edge->flags & AF_EDGE_DONE ) 2360 continue; 2361 2362 edge1 = NULL; 2363 edge2 = edge->link; 2364 2365 /* 2366 * If a stem contains both a neutral and a non-neutral blue zone, 2367 * skip the neutral one. Otherwise, outlines with different 2368 * directions might be incorrectly aligned at the same vertical 2369 * position. 2370 * 2371 * If we have two neutral blue zones, skip one of them. 2372 * 2373 */ 2374 if ( edge->blue_edge && edge2 && edge2->blue_edge ) 2375 { 2376 FT_Byte neutral = edge->flags & AF_EDGE_NEUTRAL; 2377 FT_Byte neutral2 = edge2->flags & AF_EDGE_NEUTRAL; 2378 2379 2380 if ( neutral2 ) 2381 { 2382 edge2->blue_edge = NULL; 2383 edge2->flags &= ~AF_EDGE_NEUTRAL; 2384 } 2385 else if ( neutral ) 2386 { 2387 edge->blue_edge = NULL; 2388 edge->flags &= ~AF_EDGE_NEUTRAL; 2389 } 2390 } 2391 2392 blue = edge->blue_edge; 2393 if ( blue ) 2394 edge1 = edge; 2395 2396 /* flip edges if the other edge is aligned to a blue zone */ 2397 else if ( edge2 && edge2->blue_edge ) 2398 { 2399 blue = edge2->blue_edge; 2400 edge1 = edge2; 2401 edge2 = edge; 2402 } 2403 2404 if ( !edge1 ) 2405 continue; 2406 2407 #ifdef FT_DEBUG_LEVEL_TRACE 2408 if ( !anchor ) 2409 FT_TRACE5(( " BLUE_ANCHOR: edge %d (opos=%.2f) snapped to %.2f," 2410 " was %.2f (anchor=edge %d)\n", 2411 edge1 - edges, edge1->opos / 64.0, blue->fit / 64.0, 2412 edge1->pos / 64.0, edge - edges )); 2413 else 2414 FT_TRACE5(( " BLUE: edge %d (opos=%.2f) snapped to %.2f," 2415 " was %.2f\n", 2416 edge1 - edges, edge1->opos / 64.0, blue->fit / 64.0, 2417 edge1->pos / 64.0 )); 2418 2419 num_actions++; 2420 #endif 2421 2422 edge1->pos = blue->fit; 2423 edge1->flags |= AF_EDGE_DONE; 2424 2425 if ( edge2 && !edge2->blue_edge ) 2426 { 2427 af_latin_align_linked_edge( hints, dim, edge1, edge2 ); 2428 edge2->flags |= AF_EDGE_DONE; 2429 2430 #ifdef FT_DEBUG_LEVEL_TRACE 2431 num_actions++; 2432 #endif 2433 } 2434 2435 if ( !anchor ) 2436 anchor = edge; 2437 } 2438 } 2439 2440 /* now we align all other stem edges, trying to maintain the */ 2441 /* relative order of stems in the glyph */ 2442 for ( edge = edges; edge < edge_limit; edge++ ) 2443 { 2444 AF_Edge edge2; 2445 2446 2447 if ( edge->flags & AF_EDGE_DONE ) 2448 continue; 2449 2450 /* skip all non-stem edges */ 2451 edge2 = edge->link; 2452 if ( !edge2 ) 2453 { 2454 has_serifs++; 2455 continue; 2456 } 2457 2458 /* now align the stem */ 2459 2460 /* this should not happen, but it's better to be safe */ 2461 if ( edge2->blue_edge ) 2462 { 2463 FT_TRACE5(( " ASSERTION FAILED for edge %d\n", edge2 - edges )); 2464 2465 af_latin_align_linked_edge( hints, dim, edge2, edge ); 2466 edge->flags |= AF_EDGE_DONE; 2467 2468 #ifdef FT_DEBUG_LEVEL_TRACE 2469 num_actions++; 2470 #endif 2471 continue; 2472 } 2473 2474 if ( !anchor ) 2475 { 2476 /* if we reach this if clause, no stem has been aligned yet */ 2477 2478 FT_Pos org_len, org_center, cur_len; 2479 FT_Pos cur_pos1, error1, error2, u_off, d_off; 2480 2481 2482 org_len = edge2->opos - edge->opos; 2483 cur_len = af_latin_compute_stem_width( hints, dim, org_len, 2484 edge->flags, 2485 edge2->flags ); 2486 2487 /* some voodoo to specially round edges for small stem widths; */ 2488 /* the idea is to align the center of a stem, then shifting */ 2489 /* the stem edges to suitable positions */ 2490 if ( cur_len <= 64 ) 2491 { 2492 /* width <= 1px */ 2493 u_off = 32; 2494 d_off = 32; 2495 } 2496 else 2497 { 2498 /* 1px < width < 1.5px */ 2499 u_off = 38; 2500 d_off = 26; 2501 } 2502 2503 if ( cur_len < 96 ) 2504 { 2505 org_center = edge->opos + ( org_len >> 1 ); 2506 cur_pos1 = FT_PIX_ROUND( org_center ); 2507 2508 error1 = org_center - ( cur_pos1 - u_off ); 2509 if ( error1 < 0 ) 2510 error1 = -error1; 2511 2512 error2 = org_center - ( cur_pos1 + d_off ); 2513 if ( error2 < 0 ) 2514 error2 = -error2; 2515 2516 if ( error1 < error2 ) 2517 cur_pos1 -= u_off; 2518 else 2519 cur_pos1 += d_off; 2520 2521 edge->pos = cur_pos1 - cur_len / 2; 2522 edge2->pos = edge->pos + cur_len; 2523 } 2524 else 2525 edge->pos = FT_PIX_ROUND( edge->opos ); 2526 2527 anchor = edge; 2528 edge->flags |= AF_EDGE_DONE; 2529 2530 FT_TRACE5(( " ANCHOR: edge %d (opos=%.2f) and %d (opos=%.2f)" 2531 " snapped to %.2f and %.2f\n", 2532 edge - edges, edge->opos / 64.0, 2533 edge2 - edges, edge2->opos / 64.0, 2534 edge->pos / 64.0, edge2->pos / 64.0 )); 2535 2536 af_latin_align_linked_edge( hints, dim, edge, edge2 ); 2537 2538 #ifdef FT_DEBUG_LEVEL_TRACE 2539 num_actions += 2; 2540 #endif 2541 } 2542 else 2543 { 2544 FT_Pos org_pos, org_len, org_center, cur_len; 2545 FT_Pos cur_pos1, cur_pos2, delta1, delta2; 2546 2547 2548 org_pos = anchor->pos + ( edge->opos - anchor->opos ); 2549 org_len = edge2->opos - edge->opos; 2550 org_center = org_pos + ( org_len >> 1 ); 2551 2552 cur_len = af_latin_compute_stem_width( hints, dim, org_len, 2553 edge->flags, 2554 edge2->flags ); 2555 2556 if ( edge2->flags & AF_EDGE_DONE ) 2557 { 2558 FT_TRACE5(( " ADJUST: edge %d (pos=%.2f) moved to %.2f\n", 2559 edge - edges, edge->pos / 64.0, 2560 ( edge2->pos - cur_len ) / 64.0 )); 2561 2562 edge->pos = edge2->pos - cur_len; 2563 } 2564 2565 else if ( cur_len < 96 ) 2566 { 2567 FT_Pos u_off, d_off; 2568 2569 2570 cur_pos1 = FT_PIX_ROUND( org_center ); 2571 2572 if ( cur_len <= 64 ) 2573 { 2574 u_off = 32; 2575 d_off = 32; 2576 } 2577 else 2578 { 2579 u_off = 38; 2580 d_off = 26; 2581 } 2582 2583 delta1 = org_center - ( cur_pos1 - u_off ); 2584 if ( delta1 < 0 ) 2585 delta1 = -delta1; 2586 2587 delta2 = org_center - ( cur_pos1 + d_off ); 2588 if ( delta2 < 0 ) 2589 delta2 = -delta2; 2590 2591 if ( delta1 < delta2 ) 2592 cur_pos1 -= u_off; 2593 else 2594 cur_pos1 += d_off; 2595 2596 edge->pos = cur_pos1 - cur_len / 2; 2597 edge2->pos = cur_pos1 + cur_len / 2; 2598 2599 FT_TRACE5(( " STEM: edge %d (opos=%.2f) linked to %d (opos=%.2f)" 2600 " snapped to %.2f and %.2f\n", 2601 edge - edges, edge->opos / 64.0, 2602 edge2 - edges, edge2->opos / 64.0, 2603 edge->pos / 64.0, edge2->pos / 64.0 )); 2604 } 2605 2606 else 2607 { 2608 org_pos = anchor->pos + ( edge->opos - anchor->opos ); 2609 org_len = edge2->opos - edge->opos; 2610 org_center = org_pos + ( org_len >> 1 ); 2611 2612 cur_len = af_latin_compute_stem_width( hints, dim, org_len, 2613 edge->flags, 2614 edge2->flags ); 2615 2616 cur_pos1 = FT_PIX_ROUND( org_pos ); 2617 delta1 = cur_pos1 + ( cur_len >> 1 ) - org_center; 2618 if ( delta1 < 0 ) 2619 delta1 = -delta1; 2620 2621 cur_pos2 = FT_PIX_ROUND( org_pos + org_len ) - cur_len; 2622 delta2 = cur_pos2 + ( cur_len >> 1 ) - org_center; 2623 if ( delta2 < 0 ) 2624 delta2 = -delta2; 2625 2626 edge->pos = ( delta1 < delta2 ) ? cur_pos1 : cur_pos2; 2627 edge2->pos = edge->pos + cur_len; 2628 2629 FT_TRACE5(( " STEM: edge %d (opos=%.2f) linked to %d (opos=%.2f)" 2630 " snapped to %.2f and %.2f\n", 2631 edge - edges, edge->opos / 64.0, 2632 edge2 - edges, edge2->opos / 64.0, 2633 edge->pos / 64.0, edge2->pos / 64.0 )); 2634 } 2635 2636 #ifdef FT_DEBUG_LEVEL_TRACE 2637 num_actions++; 2638 #endif 2639 2640 edge->flags |= AF_EDGE_DONE; 2641 edge2->flags |= AF_EDGE_DONE; 2642 2643 if ( edge > edges && edge->pos < edge[-1].pos ) 2644 { 2645 #ifdef FT_DEBUG_LEVEL_TRACE 2646 FT_TRACE5(( " BOUND: edge %d (pos=%.2f) moved to %.2f\n", 2647 edge - edges, edge->pos / 64.0, edge[-1].pos / 64.0 )); 2648 2649 num_actions++; 2650 #endif 2651 2652 edge->pos = edge[-1].pos; 2653 } 2654 } 2655 } 2656 2657 /* make sure that lowercase m's maintain their symmetry */ 2658 2659 /* In general, lowercase m's have six vertical edges if they are sans */ 2660 /* serif, or twelve if they are with serifs. This implementation is */ 2661 /* based on that assumption, and seems to work very well with most */ 2662 /* faces. However, if for a certain face this assumption is not */ 2663 /* true, the m is just rendered like before. In addition, any stem */ 2664 /* correction will only be applied to symmetrical glyphs (even if the */ 2665 /* glyph is not an m), so the potential for unwanted distortion is */ 2666 /* relatively low. */ 2667 2668 /* We don't handle horizontal edges since we can't easily assure that */ 2669 /* the third (lowest) stem aligns with the base line; it might end up */ 2670 /* one pixel higher or lower. */ 2671 2672 n_edges = edge_limit - edges; 2673 if ( dim == AF_DIMENSION_HORZ && ( n_edges == 6 || n_edges == 12 ) ) 2674 { 2675 AF_Edge edge1, edge2, edge3; 2676 FT_Pos dist1, dist2, span, delta; 2677 2678 2679 if ( n_edges == 6 ) 2680 { 2681 edge1 = edges; 2682 edge2 = edges + 2; 2683 edge3 = edges + 4; 2684 } 2685 else 2686 { 2687 edge1 = edges + 1; 2688 edge2 = edges + 5; 2689 edge3 = edges + 9; 2690 } 2691 2692 dist1 = edge2->opos - edge1->opos; 2693 dist2 = edge3->opos - edge2->opos; 2694 2695 span = dist1 - dist2; 2696 if ( span < 0 ) 2697 span = -span; 2698 2699 if ( span < 8 ) 2700 { 2701 delta = edge3->pos - ( 2 * edge2->pos - edge1->pos ); 2702 edge3->pos -= delta; 2703 if ( edge3->link ) 2704 edge3->link->pos -= delta; 2705 2706 /* move the serifs along with the stem */ 2707 if ( n_edges == 12 ) 2708 { 2709 ( edges + 8 )->pos -= delta; 2710 ( edges + 11 )->pos -= delta; 2711 } 2712 2713 edge3->flags |= AF_EDGE_DONE; 2714 if ( edge3->link ) 2715 edge3->link->flags |= AF_EDGE_DONE; 2716 } 2717 } 2718 2719 if ( has_serifs || !anchor ) 2720 { 2721 /* 2722 * now hint the remaining edges (serifs and single) in order 2723 * to complete our processing 2724 */ 2725 for ( edge = edges; edge < edge_limit; edge++ ) 2726 { 2727 FT_Pos delta; 2728 2729 2730 if ( edge->flags & AF_EDGE_DONE ) 2731 continue; 2732 2733 delta = 1000; 2734 2735 if ( edge->serif ) 2736 { 2737 delta = edge->serif->opos - edge->opos; 2738 if ( delta < 0 ) 2739 delta = -delta; 2740 } 2741 2742 if ( delta < 64 + 16 ) 2743 { 2744 af_latin_align_serif_edge( hints, edge->serif, edge ); 2745 FT_TRACE5(( " SERIF: edge %d (opos=%.2f) serif to %d (opos=%.2f)" 2746 " aligned to %.2f\n", 2747 edge - edges, edge->opos / 64.0, 2748 edge->serif - edges, edge->serif->opos / 64.0, 2749 edge->pos / 64.0 )); 2750 } 2751 else if ( !anchor ) 2752 { 2753 edge->pos = FT_PIX_ROUND( edge->opos ); 2754 anchor = edge; 2755 FT_TRACE5(( " SERIF_ANCHOR: edge %d (opos=%.2f)" 2756 " snapped to %.2f\n", 2757 edge-edges, edge->opos / 64.0, edge->pos / 64.0 )); 2758 } 2759 else 2760 { 2761 AF_Edge before, after; 2762 2763 2764 for ( before = edge - 1; before >= edges; before-- ) 2765 if ( before->flags & AF_EDGE_DONE ) 2766 break; 2767 2768 for ( after = edge + 1; after < edge_limit; after++ ) 2769 if ( after->flags & AF_EDGE_DONE ) 2770 break; 2771 2772 if ( before >= edges && before < edge && 2773 after < edge_limit && after > edge ) 2774 { 2775 if ( after->opos == before->opos ) 2776 edge->pos = before->pos; 2777 else 2778 edge->pos = before->pos + 2779 FT_MulDiv( edge->opos - before->opos, 2780 after->pos - before->pos, 2781 after->opos - before->opos ); 2782 2783 FT_TRACE5(( " SERIF_LINK1: edge %d (opos=%.2f) snapped to %.2f" 2784 " from %d (opos=%.2f)\n", 2785 edge - edges, edge->opos / 64.0, 2786 edge->pos / 64.0, 2787 before - edges, before->opos / 64.0 )); 2788 } 2789 else 2790 { 2791 edge->pos = anchor->pos + 2792 ( ( edge->opos - anchor->opos + 16 ) & ~31 ); 2793 FT_TRACE5(( " SERIF_LINK2: edge %d (opos=%.2f)" 2794 " snapped to %.2f\n", 2795 edge - edges, edge->opos / 64.0, edge->pos / 64.0 )); 2796 } 2797 } 2798 2799 #ifdef FT_DEBUG_LEVEL_TRACE 2800 num_actions++; 2801 #endif 2802 edge->flags |= AF_EDGE_DONE; 2803 2804 if ( edge > edges && edge->pos < edge[-1].pos ) 2805 { 2806 #ifdef FT_DEBUG_LEVEL_TRACE 2807 FT_TRACE5(( " BOUND: edge %d (pos=%.2f) moved to %.2f\n", 2808 edge - edges, edge->pos / 64.0, edge[-1].pos / 64.0 )); 2809 2810 num_actions++; 2811 #endif 2812 edge->pos = edge[-1].pos; 2813 } 2814 2815 if ( edge + 1 < edge_limit && 2816 edge[1].flags & AF_EDGE_DONE && 2817 edge->pos > edge[1].pos ) 2818 { 2819 #ifdef FT_DEBUG_LEVEL_TRACE 2820 FT_TRACE5(( " BOUND: edge %d (pos=%.2f) moved to %.2f\n", 2821 edge - edges, edge->pos / 64.0, edge[1].pos / 64.0 )); 2822 2823 num_actions++; 2824 #endif 2825 2826 edge->pos = edge[1].pos; 2827 } 2828 } 2829 } 2830 2831 #ifdef FT_DEBUG_LEVEL_TRACE 2832 if ( !num_actions ) 2833 FT_TRACE5(( " (none)\n" )); 2834 FT_TRACE5(( "\n" )); 2835 #endif 2836 } 2837 2838 2839 /* Apply the complete hinting algorithm to a latin glyph. */ 2840 2841 static FT_Error af_latin_hints_apply(FT_UInt glyph_index,AF_GlyphHints hints,FT_Outline * outline,AF_LatinMetrics metrics)2842 af_latin_hints_apply( FT_UInt glyph_index, 2843 AF_GlyphHints hints, 2844 FT_Outline* outline, 2845 AF_LatinMetrics metrics ) 2846 { 2847 FT_Error error; 2848 int dim; 2849 2850 AF_LatinAxis axis; 2851 2852 2853 error = af_glyph_hints_reload( hints, outline ); 2854 if ( error ) 2855 goto Exit; 2856 2857 /* analyze glyph outline */ 2858 #ifdef AF_CONFIG_OPTION_USE_WARPER 2859 if ( ( metrics->root.scaler.render_mode == FT_RENDER_MODE_LIGHT && 2860 AF_HINTS_DO_WARP( hints ) ) || 2861 AF_HINTS_DO_HORIZONTAL( hints ) ) 2862 #else 2863 if ( AF_HINTS_DO_HORIZONTAL( hints ) ) 2864 #endif 2865 { 2866 axis = &metrics->axis[AF_DIMENSION_HORZ]; 2867 error = af_latin_hints_detect_features( hints, 2868 axis->width_count, 2869 axis->widths, 2870 AF_DIMENSION_HORZ ); 2871 if ( error ) 2872 goto Exit; 2873 } 2874 2875 if ( AF_HINTS_DO_VERTICAL( hints ) ) 2876 { 2877 axis = &metrics->axis[AF_DIMENSION_VERT]; 2878 error = af_latin_hints_detect_features( hints, 2879 axis->width_count, 2880 axis->widths, 2881 AF_DIMENSION_VERT ); 2882 if ( error ) 2883 goto Exit; 2884 2885 /* apply blue zones to base characters only */ 2886 if ( !( metrics->root.globals->glyph_styles[glyph_index] & AF_NONBASE ) ) 2887 af_latin_hints_compute_blue_edges( hints, metrics ); 2888 } 2889 2890 /* grid-fit the outline */ 2891 for ( dim = 0; dim < AF_DIMENSION_MAX; dim++ ) 2892 { 2893 #ifdef AF_CONFIG_OPTION_USE_WARPER 2894 if ( dim == AF_DIMENSION_HORZ && 2895 metrics->root.scaler.render_mode == FT_RENDER_MODE_LIGHT && 2896 AF_HINTS_DO_WARP( hints ) ) 2897 { 2898 AF_WarperRec warper; 2899 FT_Fixed scale; 2900 FT_Pos delta; 2901 2902 2903 af_warper_compute( &warper, hints, (AF_Dimension)dim, 2904 &scale, &delta ); 2905 af_glyph_hints_scale_dim( hints, (AF_Dimension)dim, 2906 scale, delta ); 2907 continue; 2908 } 2909 #endif /* AF_CONFIG_OPTION_USE_WARPER */ 2910 2911 if ( ( dim == AF_DIMENSION_HORZ && AF_HINTS_DO_HORIZONTAL( hints ) ) || 2912 ( dim == AF_DIMENSION_VERT && AF_HINTS_DO_VERTICAL( hints ) ) ) 2913 { 2914 af_latin_hint_edges( hints, (AF_Dimension)dim ); 2915 af_glyph_hints_align_edge_points( hints, (AF_Dimension)dim ); 2916 af_glyph_hints_align_strong_points( hints, (AF_Dimension)dim ); 2917 af_glyph_hints_align_weak_points( hints, (AF_Dimension)dim ); 2918 } 2919 } 2920 2921 af_glyph_hints_save( hints, outline ); 2922 2923 Exit: 2924 return error; 2925 } 2926 2927 2928 /*************************************************************************/ 2929 /*************************************************************************/ 2930 /***** *****/ 2931 /***** L A T I N S C R I P T C L A S S *****/ 2932 /***** *****/ 2933 /*************************************************************************/ 2934 /*************************************************************************/ 2935 2936 2937 AF_DEFINE_WRITING_SYSTEM_CLASS( 2938 af_latin_writing_system_class, 2939 2940 AF_WRITING_SYSTEM_LATIN, 2941 2942 sizeof ( AF_LatinMetricsRec ), 2943 2944 (AF_WritingSystem_InitMetricsFunc) af_latin_metrics_init, 2945 (AF_WritingSystem_ScaleMetricsFunc)af_latin_metrics_scale, 2946 (AF_WritingSystem_DoneMetricsFunc) NULL, 2947 2948 (AF_WritingSystem_InitHintsFunc) af_latin_hints_init, 2949 (AF_WritingSystem_ApplyHintsFunc) af_latin_hints_apply 2950 ) 2951 2952 2953 /* END */ 2954