1 /***************************************************************************/ 2 /* */ 3 /* aflatin.c */ 4 /* */ 5 /* Auto-fitter hinting routines for latin script (body). */ 6 /* */ 7 /* Copyright 2003-2013 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 "aflatin.h" 25 #include "aferrors.h" 26 27 28 #ifdef AF_CONFIG_OPTION_USE_WARPER 29 #include "afwarp.h" 30 #endif 31 32 33 /*************************************************************************/ 34 /* */ 35 /* The macro FT_COMPONENT is used in trace mode. It is an implicit */ 36 /* parameter of the FT_TRACE() and FT_ERROR() macros, used to print/log */ 37 /* messages during execution. */ 38 /* */ 39 #undef FT_COMPONENT 40 #define FT_COMPONENT trace_aflatin 41 42 43 /*************************************************************************/ 44 /*************************************************************************/ 45 /***** *****/ 46 /***** L A T I N G L O B A L M E T R I C S *****/ 47 /***** *****/ 48 /*************************************************************************/ 49 /*************************************************************************/ 50 51 52 /* Find segments and links, compute all stem widths, and initialize */ 53 /* standard width and height for the glyph with given charcode. */ 54 55 FT_LOCAL_DEF( void ) 56 af_latin_metrics_init_widths( AF_LatinMetrics metrics, 57 FT_Face face ) 58 { 59 /* scan the array of segments in each direction */ 60 AF_GlyphHintsRec hints[1]; 61 62 63 FT_TRACE5(( "standard widths computation\n" 64 "===========================\n\n" )); 65 66 af_glyph_hints_init( hints, face->memory ); 67 68 metrics->axis[AF_DIMENSION_HORZ].width_count = 0; 69 metrics->axis[AF_DIMENSION_VERT].width_count = 0; 70 71 { 72 FT_Error error; 73 FT_UInt glyph_index; 74 int dim; 75 AF_LatinMetricsRec dummy[1]; 76 AF_Scaler scaler = &dummy->root.scaler; 77 78 79 glyph_index = FT_Get_Char_Index( face, 80 metrics->root.clazz->standard_char ); 81 if ( glyph_index == 0 ) 82 goto Exit; 83 84 FT_TRACE5(( "standard character: 0x%X (glyph index %d)\n", 85 metrics->root.clazz->standard_char, glyph_index )); 86 87 error = FT_Load_Glyph( face, glyph_index, FT_LOAD_NO_SCALE ); 88 if ( error || face->glyph->outline.n_points <= 0 ) 89 goto Exit; 90 91 FT_ZERO( dummy ); 92 93 dummy->units_per_em = metrics->units_per_em; 94 95 scaler->x_scale = 0x10000L; 96 scaler->y_scale = 0x10000L; 97 scaler->x_delta = 0; 98 scaler->y_delta = 0; 99 100 scaler->face = face; 101 scaler->render_mode = FT_RENDER_MODE_NORMAL; 102 scaler->flags = 0; 103 104 af_glyph_hints_rescale( hints, (AF_ScriptMetrics)dummy ); 105 106 error = af_glyph_hints_reload( hints, &face->glyph->outline ); 107 if ( error ) 108 goto Exit; 109 110 for ( dim = 0; dim < AF_DIMENSION_MAX; dim++ ) 111 { 112 AF_LatinAxis axis = &metrics->axis[dim]; 113 AF_AxisHints axhints = &hints->axis[dim]; 114 AF_Segment seg, limit, link; 115 FT_UInt num_widths = 0; 116 117 118 error = af_latin_hints_compute_segments( hints, 119 (AF_Dimension)dim ); 120 if ( error ) 121 goto Exit; 122 123 af_latin_hints_link_segments( hints, 124 (AF_Dimension)dim ); 125 126 seg = axhints->segments; 127 limit = seg + axhints->num_segments; 128 129 for ( ; seg < limit; seg++ ) 130 { 131 link = seg->link; 132 133 /* we only consider stem segments there! */ 134 if ( link && link->link == seg && link > seg ) 135 { 136 FT_Pos dist; 137 138 139 dist = seg->pos - link->pos; 140 if ( dist < 0 ) 141 dist = -dist; 142 143 if ( num_widths < AF_LATIN_MAX_WIDTHS ) 144 axis->widths[num_widths++].org = dist; 145 } 146 } 147 148 /* this also replaces multiple almost identical stem widths */ 149 /* with a single one (the value 100 is heuristic) */ 150 af_sort_and_quantize_widths( &num_widths, axis->widths, 151 dummy->units_per_em / 100 ); 152 axis->width_count = num_widths; 153 } 154 155 Exit: 156 for ( dim = 0; dim < AF_DIMENSION_MAX; dim++ ) 157 { 158 AF_LatinAxis axis = &metrics->axis[dim]; 159 FT_Pos stdw; 160 161 162 stdw = ( axis->width_count > 0 ) 163 ? axis->widths[0].org 164 : AF_LATIN_CONSTANT( metrics, 50 ); 165 166 /* let's try 20% of the smallest width */ 167 axis->edge_distance_threshold = stdw / 5; 168 axis->standard_width = stdw; 169 axis->extra_light = 0; 170 171 #ifdef FT_DEBUG_LEVEL_TRACE 172 { 173 FT_UInt i; 174 175 176 FT_TRACE5(( "%s widths:\n", 177 dim == AF_DIMENSION_VERT ? "horizontal" 178 : "vertical" )); 179 180 FT_TRACE5(( " %d (standard)", axis->standard_width )); 181 for ( i = 1; i < axis->width_count; i++ ) 182 FT_TRACE5(( " %d", axis->widths[i].org )); 183 184 FT_TRACE5(( "\n" )); 185 } 186 #endif 187 } 188 } 189 190 FT_TRACE5(( "\n" )); 191 192 af_glyph_hints_done( hints ); 193 } 194 195 196 197 #define AF_LATIN_MAX_TEST_CHARACTERS 12 198 199 200 static const char af_latin_blue_chars[AF_LATIN_MAX_BLUES] 201 [AF_LATIN_MAX_TEST_CHARACTERS + 1] = 202 { 203 "THEZOCQS", 204 "HEZLOCUS", 205 "fijkdbh", 206 "xzroesc", 207 "xzroesc", 208 "pqgjy" 209 }; 210 211 212 /* Find all blue zones. Flat segments give the reference points, */ 213 /* round segments the overshoot positions. */ 214 215 static void 216 af_latin_metrics_init_blues( AF_LatinMetrics metrics, 217 FT_Face face ) 218 { 219 FT_Pos flats [AF_LATIN_MAX_TEST_CHARACTERS]; 220 FT_Pos rounds[AF_LATIN_MAX_TEST_CHARACTERS]; 221 FT_Int num_flats; 222 FT_Int num_rounds; 223 FT_Int bb; 224 AF_LatinBlue blue; 225 FT_Error error; 226 AF_LatinAxis axis = &metrics->axis[AF_DIMENSION_VERT]; 227 FT_Outline outline; 228 229 230 /* we compute the blues simply by loading each character from the */ 231 /* `af_latin_blue_chars[blues]' string, then finding its top-most or */ 232 /* bottom-most points (depending on `AF_IS_TOP_BLUE') */ 233 234 FT_TRACE5(( "blue zones computation\n" 235 "======================\n\n" )); 236 237 for ( bb = 0; bb < AF_LATIN_BLUE_MAX; bb++ ) 238 { 239 const char* p = af_latin_blue_chars[bb]; 240 const char* limit = p + AF_LATIN_MAX_TEST_CHARACTERS; 241 FT_Pos* blue_ref; 242 FT_Pos* blue_shoot; 243 244 245 FT_TRACE5(( "blue zone %d:\n", bb )); 246 247 num_flats = 0; 248 num_rounds = 0; 249 250 for ( ; p < limit && *p; p++ ) 251 { 252 FT_UInt glyph_index; 253 FT_Pos best_y; /* same as points.y */ 254 FT_Int best_point, best_contour_first, best_contour_last; 255 FT_Vector* points; 256 FT_Bool round = 0; 257 258 259 /* load the character in the face -- skip unknown or empty ones */ 260 glyph_index = FT_Get_Char_Index( face, (FT_UInt)*p ); 261 if ( glyph_index == 0 ) 262 continue; 263 264 error = FT_Load_Glyph( face, glyph_index, FT_LOAD_NO_SCALE ); 265 outline = face->glyph->outline; 266 if ( error || outline.n_points <= 0 ) 267 continue; 268 269 /* now compute min or max point indices and coordinates */ 270 points = outline.points; 271 best_point = -1; 272 best_y = 0; /* make compiler happy */ 273 best_contour_first = 0; /* ditto */ 274 best_contour_last = 0; /* ditto */ 275 276 { 277 FT_Int nn; 278 FT_Int first = 0; 279 FT_Int last = -1; 280 281 282 for ( nn = 0; nn < outline.n_contours; first = last + 1, nn++ ) 283 { 284 FT_Int old_best_point = best_point; 285 FT_Int pp; 286 287 288 last = outline.contours[nn]; 289 290 /* Avoid single-point contours since they are never rasterized. */ 291 /* In some fonts, they correspond to mark attachment points */ 292 /* which are way outside of the glyph's real outline. */ 293 if ( last <= first ) 294 continue; 295 296 if ( AF_LATIN_IS_TOP_BLUE( bb ) ) 297 { 298 for ( pp = first; pp <= last; pp++ ) 299 if ( best_point < 0 || points[pp].y > best_y ) 300 { 301 best_point = pp; 302 best_y = points[pp].y; 303 } 304 } 305 else 306 { 307 for ( pp = first; pp <= last; pp++ ) 308 if ( best_point < 0 || points[pp].y < best_y ) 309 { 310 best_point = pp; 311 best_y = points[pp].y; 312 } 313 } 314 315 if ( best_point != old_best_point ) 316 { 317 best_contour_first = first; 318 best_contour_last = last; 319 } 320 } 321 FT_TRACE5(( " %c %ld", *p, best_y )); 322 } 323 324 /* now check whether the point belongs to a straight or round */ 325 /* segment; we first need to find in which contour the extremum */ 326 /* lies, then inspect its previous and next points */ 327 if ( best_point >= 0 ) 328 { 329 FT_Pos best_x = points[best_point].x; 330 FT_Int prev, next; 331 FT_Int best_on_point_first, best_on_point_last; 332 FT_Pos dist; 333 334 335 if ( FT_CURVE_TAG( outline.tags[best_point] ) == FT_CURVE_TAG_ON ) 336 { 337 best_on_point_first = best_point; 338 best_on_point_last = best_point; 339 } 340 else 341 { 342 best_on_point_first = -1; 343 best_on_point_last = -1; 344 } 345 346 /* look for the previous and next points that are not on the */ 347 /* same Y coordinate, then threshold the `closeness'... */ 348 prev = best_point; 349 next = prev; 350 351 do 352 { 353 if ( prev > best_contour_first ) 354 prev--; 355 else 356 prev = best_contour_last; 357 358 dist = FT_ABS( points[prev].y - best_y ); 359 /* accept a small distance or a small angle (both values are */ 360 /* heuristic; value 20 corresponds to approx. 2.9 degrees) */ 361 if ( dist > 5 ) 362 if ( FT_ABS( points[prev].x - best_x ) <= 20 * dist ) 363 break; 364 365 if ( FT_CURVE_TAG( outline.tags[prev] ) == FT_CURVE_TAG_ON ) 366 { 367 best_on_point_first = prev; 368 if ( best_on_point_last < 0 ) 369 best_on_point_last = prev; 370 } 371 372 } while ( prev != best_point ); 373 374 do 375 { 376 if ( next < best_contour_last ) 377 next++; 378 else 379 next = best_contour_first; 380 381 dist = FT_ABS( points[next].y - best_y ); 382 if ( dist > 5 ) 383 if ( FT_ABS( points[next].x - best_x ) <= 20 * dist ) 384 break; 385 386 if ( FT_CURVE_TAG( outline.tags[next] ) == FT_CURVE_TAG_ON ) 387 { 388 best_on_point_last = next; 389 if ( best_on_point_first < 0 ) 390 best_on_point_first = next; 391 } 392 393 } while ( next != best_point ); 394 395 /* now set the `round' flag depending on the segment's kind */ 396 /* (value 8 is heuristic) */ 397 if ( best_on_point_first >= 0 && 398 best_on_point_last >= 0 && 399 (FT_UInt)( FT_ABS( points[best_on_point_last].x - 400 points[best_on_point_first].x ) ) > 401 metrics->units_per_em / 8 ) 402 round = 0; 403 else 404 round = FT_BOOL( 405 FT_CURVE_TAG( outline.tags[prev] ) != FT_CURVE_TAG_ON || 406 FT_CURVE_TAG( outline.tags[next] ) != FT_CURVE_TAG_ON ); 407 408 FT_TRACE5(( " (%s)\n", round ? "round" : "flat" )); 409 } 410 411 if ( round ) 412 rounds[num_rounds++] = best_y; 413 else 414 flats[num_flats++] = best_y; 415 } 416 417 if ( num_flats == 0 && num_rounds == 0 ) 418 { 419 /* 420 * we couldn't find a single glyph to compute this blue zone, 421 * we will simply ignore it then 422 */ 423 FT_TRACE5(( " empty\n" )); 424 continue; 425 } 426 427 /* we have computed the contents of the `rounds' and `flats' tables, */ 428 /* now determine the reference and overshoot position of the blue -- */ 429 /* we simply take the median value after a simple sort */ 430 af_sort_pos( num_rounds, rounds ); 431 af_sort_pos( num_flats, flats ); 432 433 blue = &axis->blues[axis->blue_count]; 434 blue_ref = &blue->ref.org; 435 blue_shoot = &blue->shoot.org; 436 437 axis->blue_count++; 438 439 if ( num_flats == 0 ) 440 { 441 *blue_ref = 442 *blue_shoot = rounds[num_rounds / 2]; 443 } 444 else if ( num_rounds == 0 ) 445 { 446 *blue_ref = 447 *blue_shoot = flats[num_flats / 2]; 448 } 449 else 450 { 451 *blue_ref = flats[num_flats / 2]; 452 *blue_shoot = rounds[num_rounds / 2]; 453 } 454 455 /* there are sometimes problems: if the overshoot position of top */ 456 /* zones is under its reference position, or the opposite for bottom */ 457 /* zones. We must thus check everything there and correct the errors */ 458 if ( *blue_shoot != *blue_ref ) 459 { 460 FT_Pos ref = *blue_ref; 461 FT_Pos shoot = *blue_shoot; 462 FT_Bool over_ref = FT_BOOL( shoot > ref ); 463 464 465 if ( AF_LATIN_IS_TOP_BLUE( bb ) ^ over_ref ) 466 { 467 *blue_ref = 468 *blue_shoot = ( shoot + ref ) / 2; 469 470 FT_TRACE5(( " [overshoot smaller than reference," 471 " taking mean value]\n" )); 472 } 473 } 474 475 blue->flags = 0; 476 if ( AF_LATIN_IS_TOP_BLUE( bb ) ) 477 blue->flags |= AF_LATIN_BLUE_TOP; 478 479 /* 480 * The following flag is used later to adjust the y and x scales 481 * in order to optimize the pixel grid alignment of the top of small 482 * letters. 483 */ 484 if ( bb == AF_LATIN_BLUE_SMALL_TOP ) 485 blue->flags |= AF_LATIN_BLUE_ADJUSTMENT; 486 487 FT_TRACE5(( " -> reference = %ld\n" 488 " overshoot = %ld\n", 489 *blue_ref, *blue_shoot )); 490 } 491 492 FT_TRACE5(( "\n" )); 493 494 return; 495 } 496 497 498 /* Check whether all ASCII digits have the same advance width. */ 499 500 FT_LOCAL_DEF( void ) 501 af_latin_metrics_check_digits( AF_LatinMetrics metrics, 502 FT_Face face ) 503 { 504 FT_UInt i; 505 FT_Bool started = 0, same_width = 1; 506 FT_Fixed advance, old_advance = 0; 507 508 509 /* digit `0' is 0x30 in all supported charmaps */ 510 for ( i = 0x30; i <= 0x39; i++ ) 511 { 512 FT_UInt glyph_index; 513 514 515 glyph_index = FT_Get_Char_Index( face, i ); 516 if ( glyph_index == 0 ) 517 continue; 518 519 if ( FT_Get_Advance( face, glyph_index, 520 FT_LOAD_NO_SCALE | 521 FT_LOAD_NO_HINTING | 522 FT_LOAD_IGNORE_TRANSFORM, 523 &advance ) ) 524 continue; 525 526 if ( started ) 527 { 528 if ( advance != old_advance ) 529 { 530 same_width = 0; 531 break; 532 } 533 } 534 else 535 { 536 old_advance = advance; 537 started = 1; 538 } 539 } 540 541 metrics->root.digits_have_same_width = same_width; 542 } 543 544 545 /* Initialize global metrics. */ 546 547 FT_LOCAL_DEF( FT_Error ) 548 af_latin_metrics_init( AF_LatinMetrics metrics, 549 FT_Face face ) 550 { 551 FT_CharMap oldmap = face->charmap; 552 553 554 metrics->units_per_em = face->units_per_EM; 555 556 if ( !FT_Select_Charmap( face, FT_ENCODING_UNICODE ) ) 557 { 558 af_latin_metrics_init_widths( metrics, face ); 559 af_latin_metrics_init_blues( metrics, face ); 560 af_latin_metrics_check_digits( metrics, face ); 561 } 562 563 FT_Set_Charmap( face, oldmap ); 564 return FT_Err_Ok; 565 } 566 567 568 /* Adjust scaling value, then scale and shift widths */ 569 /* and blue zones (if applicable) for given dimension. */ 570 571 static void 572 af_latin_metrics_scale_dim( AF_LatinMetrics metrics, 573 AF_Scaler scaler, 574 AF_Dimension dim ) 575 { 576 FT_Fixed scale; 577 FT_Pos delta; 578 AF_LatinAxis axis; 579 FT_UInt nn; 580 581 582 if ( dim == AF_DIMENSION_HORZ ) 583 { 584 scale = scaler->x_scale; 585 delta = scaler->x_delta; 586 } 587 else 588 { 589 scale = scaler->y_scale; 590 delta = scaler->y_delta; 591 } 592 593 axis = &metrics->axis[dim]; 594 595 if ( axis->org_scale == scale && axis->org_delta == delta ) 596 return; 597 598 axis->org_scale = scale; 599 axis->org_delta = delta; 600 601 /* 602 * correct X and Y scale to optimize the alignment of the top of small 603 * letters to the pixel grid 604 */ 605 { 606 AF_LatinAxis Axis = &metrics->axis[AF_DIMENSION_VERT]; 607 AF_LatinBlue blue = NULL; 608 609 610 for ( nn = 0; nn < Axis->blue_count; nn++ ) 611 { 612 if ( Axis->blues[nn].flags & AF_LATIN_BLUE_ADJUSTMENT ) 613 { 614 blue = &Axis->blues[nn]; 615 break; 616 } 617 } 618 619 if ( blue ) 620 { 621 FT_Pos scaled; 622 FT_Pos threshold; 623 FT_Pos fitted; 624 FT_UInt limit; 625 FT_UInt ppem; 626 627 628 scaled = FT_MulFix( blue->shoot.org, scaler->y_scale ); 629 ppem = metrics->root.scaler.face->size->metrics.x_ppem; 630 limit = metrics->root.globals->increase_x_height; 631 threshold = 40; 632 633 /* if the `increase-x-height' property is active, */ 634 /* we round up much more often */ 635 if ( limit && 636 ppem <= limit && 637 ppem >= AF_PROP_INCREASE_X_HEIGHT_MIN ) 638 threshold = 52; 639 640 fitted = ( scaled + threshold ) & ~63; 641 642 if ( scaled != fitted ) 643 { 644 #if 0 645 if ( dim == AF_DIMENSION_HORZ ) 646 { 647 if ( fitted < scaled ) 648 scale -= scale / 50; /* scale *= 0.98 */ 649 } 650 else 651 #endif 652 if ( dim == AF_DIMENSION_VERT ) 653 scale = FT_MulDiv( scale, fitted, scaled ); 654 } 655 } 656 } 657 658 axis->scale = scale; 659 axis->delta = delta; 660 661 if ( dim == AF_DIMENSION_HORZ ) 662 { 663 metrics->root.scaler.x_scale = scale; 664 metrics->root.scaler.x_delta = delta; 665 } 666 else 667 { 668 metrics->root.scaler.y_scale = scale; 669 metrics->root.scaler.y_delta = delta; 670 } 671 672 /* scale the widths */ 673 for ( nn = 0; nn < axis->width_count; nn++ ) 674 { 675 AF_Width width = axis->widths + nn; 676 677 678 width->cur = FT_MulFix( width->org, scale ); 679 width->fit = width->cur; 680 } 681 682 /* an extra-light axis corresponds to a standard width that is */ 683 /* smaller than 5/8 pixels */ 684 axis->extra_light = 685 (FT_Bool)( FT_MulFix( axis->standard_width, scale ) < 32 + 8 ); 686 687 if ( dim == AF_DIMENSION_VERT ) 688 { 689 /* scale the blue zones */ 690 for ( nn = 0; nn < axis->blue_count; nn++ ) 691 { 692 AF_LatinBlue blue = &axis->blues[nn]; 693 FT_Pos dist; 694 695 696 blue->ref.cur = FT_MulFix( blue->ref.org, scale ) + delta; 697 blue->ref.fit = blue->ref.cur; 698 blue->shoot.cur = FT_MulFix( blue->shoot.org, scale ) + delta; 699 blue->shoot.fit = blue->shoot.cur; 700 blue->flags &= ~AF_LATIN_BLUE_ACTIVE; 701 702 /* a blue zone is only active if it is less than 3/4 pixels tall */ 703 dist = FT_MulFix( blue->ref.org - blue->shoot.org, scale ); 704 if ( dist <= 48 && dist >= -48 ) 705 { 706 #if 0 707 FT_Pos delta1; 708 #endif 709 FT_Pos delta2; 710 711 712 /* use discrete values for blue zone widths */ 713 714 #if 0 715 716 /* generic, original code */ 717 delta1 = blue->shoot.org - blue->ref.org; 718 delta2 = delta1; 719 if ( delta1 < 0 ) 720 delta2 = -delta2; 721 722 delta2 = FT_MulFix( delta2, scale ); 723 724 if ( delta2 < 32 ) 725 delta2 = 0; 726 else if ( delta2 < 64 ) 727 delta2 = 32 + ( ( ( delta2 - 32 ) + 16 ) & ~31 ); 728 else 729 delta2 = FT_PIX_ROUND( delta2 ); 730 731 if ( delta1 < 0 ) 732 delta2 = -delta2; 733 734 blue->ref.fit = FT_PIX_ROUND( blue->ref.cur ); 735 blue->shoot.fit = blue->ref.fit + delta2; 736 737 #else 738 739 /* simplified version due to abs(dist) <= 48 */ 740 delta2 = dist; 741 if ( dist < 0 ) 742 delta2 = -delta2; 743 744 if ( delta2 < 32 ) 745 delta2 = 0; 746 else if ( delta2 < 48 ) 747 delta2 = 32; 748 else 749 delta2 = 64; 750 751 if ( dist < 0 ) 752 delta2 = -delta2; 753 754 blue->ref.fit = FT_PIX_ROUND( blue->ref.cur ); 755 blue->shoot.fit = blue->ref.fit - delta2; 756 757 #endif 758 759 blue->flags |= AF_LATIN_BLUE_ACTIVE; 760 } 761 } 762 } 763 } 764 765 766 /* Scale global values in both directions. */ 767 768 FT_LOCAL_DEF( void ) 769 af_latin_metrics_scale( AF_LatinMetrics metrics, 770 AF_Scaler scaler ) 771 { 772 metrics->root.scaler.render_mode = scaler->render_mode; 773 metrics->root.scaler.face = scaler->face; 774 metrics->root.scaler.flags = scaler->flags; 775 776 af_latin_metrics_scale_dim( metrics, scaler, AF_DIMENSION_HORZ ); 777 af_latin_metrics_scale_dim( metrics, scaler, AF_DIMENSION_VERT ); 778 } 779 780 781 /*************************************************************************/ 782 /*************************************************************************/ 783 /***** *****/ 784 /***** L A T I N G L Y P H A N A L Y S I S *****/ 785 /***** *****/ 786 /*************************************************************************/ 787 /*************************************************************************/ 788 789 790 /* Walk over all contours and compute its segments. */ 791 792 FT_LOCAL_DEF( FT_Error ) 793 af_latin_hints_compute_segments( AF_GlyphHints hints, 794 AF_Dimension dim ) 795 { 796 AF_AxisHints axis = &hints->axis[dim]; 797 FT_Memory memory = hints->memory; 798 FT_Error error = FT_Err_Ok; 799 AF_Segment segment = NULL; 800 AF_SegmentRec seg0; 801 AF_Point* contour = hints->contours; 802 AF_Point* contour_limit = contour + hints->num_contours; 803 AF_Direction major_dir, segment_dir; 804 805 806 FT_ZERO( &seg0 ); 807 seg0.score = 32000; 808 seg0.flags = AF_EDGE_NORMAL; 809 810 major_dir = (AF_Direction)FT_ABS( axis->major_dir ); 811 segment_dir = major_dir; 812 813 axis->num_segments = 0; 814 815 /* set up (u,v) in each point */ 816 if ( dim == AF_DIMENSION_HORZ ) 817 { 818 AF_Point point = hints->points; 819 AF_Point limit = point + hints->num_points; 820 821 822 for ( ; point < limit; point++ ) 823 { 824 point->u = point->fx; 825 point->v = point->fy; 826 } 827 } 828 else 829 { 830 AF_Point point = hints->points; 831 AF_Point limit = point + hints->num_points; 832 833 834 for ( ; point < limit; point++ ) 835 { 836 point->u = point->fy; 837 point->v = point->fx; 838 } 839 } 840 841 /* do each contour separately */ 842 for ( ; contour < contour_limit; contour++ ) 843 { 844 AF_Point point = contour[0]; 845 AF_Point last = point->prev; 846 int on_edge = 0; 847 FT_Pos min_pos = 32000; /* minimum segment pos != min_coord */ 848 FT_Pos max_pos = -32000; /* maximum segment pos != max_coord */ 849 FT_Bool passed; 850 851 852 if ( point == last ) /* skip singletons -- just in case */ 853 continue; 854 855 if ( FT_ABS( last->out_dir ) == major_dir && 856 FT_ABS( point->out_dir ) == major_dir ) 857 { 858 /* we are already on an edge, try to locate its start */ 859 last = point; 860 861 for (;;) 862 { 863 point = point->prev; 864 if ( FT_ABS( point->out_dir ) != major_dir ) 865 { 866 point = point->next; 867 break; 868 } 869 if ( point == last ) 870 break; 871 } 872 } 873 874 last = point; 875 passed = 0; 876 877 for (;;) 878 { 879 FT_Pos u, v; 880 881 882 if ( on_edge ) 883 { 884 u = point->u; 885 if ( u < min_pos ) 886 min_pos = u; 887 if ( u > max_pos ) 888 max_pos = u; 889 890 if ( point->out_dir != segment_dir || point == last ) 891 { 892 /* we are just leaving an edge; record a new segment! */ 893 segment->last = point; 894 segment->pos = (FT_Short)( ( min_pos + max_pos ) >> 1 ); 895 896 /* a segment is round if either its first or last point */ 897 /* is a control point */ 898 if ( ( segment->first->flags | point->flags ) & 899 AF_FLAG_CONTROL ) 900 segment->flags |= AF_EDGE_ROUND; 901 902 /* compute segment size */ 903 min_pos = max_pos = point->v; 904 905 v = segment->first->v; 906 if ( v < min_pos ) 907 min_pos = v; 908 if ( v > max_pos ) 909 max_pos = v; 910 911 segment->min_coord = (FT_Short)min_pos; 912 segment->max_coord = (FT_Short)max_pos; 913 segment->height = (FT_Short)( segment->max_coord - 914 segment->min_coord ); 915 916 on_edge = 0; 917 segment = NULL; 918 /* fall through */ 919 } 920 } 921 922 /* now exit if we are at the start/end point */ 923 if ( point == last ) 924 { 925 if ( passed ) 926 break; 927 passed = 1; 928 } 929 930 if ( !on_edge && FT_ABS( point->out_dir ) == major_dir ) 931 { 932 /* this is the start of a new segment! */ 933 segment_dir = (AF_Direction)point->out_dir; 934 935 /* clear all segment fields */ 936 error = af_axis_hints_new_segment( axis, memory, &segment ); 937 if ( error ) 938 goto Exit; 939 940 segment[0] = seg0; 941 segment->dir = (FT_Char)segment_dir; 942 min_pos = max_pos = point->u; 943 segment->first = point; 944 segment->last = point; 945 on_edge = 1; 946 } 947 948 point = point->next; 949 } 950 951 } /* contours */ 952 953 954 /* now slightly increase the height of segments if this makes */ 955 /* sense -- this is used to better detect and ignore serifs */ 956 { 957 AF_Segment segments = axis->segments; 958 AF_Segment segments_end = segments + axis->num_segments; 959 960 961 for ( segment = segments; segment < segments_end; segment++ ) 962 { 963 AF_Point first = segment->first; 964 AF_Point last = segment->last; 965 FT_Pos first_v = first->v; 966 FT_Pos last_v = last->v; 967 968 969 if ( first == last ) 970 continue; 971 972 if ( first_v < last_v ) 973 { 974 AF_Point p; 975 976 977 p = first->prev; 978 if ( p->v < first_v ) 979 segment->height = (FT_Short)( segment->height + 980 ( ( first_v - p->v ) >> 1 ) ); 981 982 p = last->next; 983 if ( p->v > last_v ) 984 segment->height = (FT_Short)( segment->height + 985 ( ( p->v - last_v ) >> 1 ) ); 986 } 987 else 988 { 989 AF_Point p; 990 991 992 p = first->prev; 993 if ( p->v > first_v ) 994 segment->height = (FT_Short)( segment->height + 995 ( ( p->v - first_v ) >> 1 ) ); 996 997 p = last->next; 998 if ( p->v < last_v ) 999 segment->height = (FT_Short)( segment->height + 1000 ( ( last_v - p->v ) >> 1 ) ); 1001 } 1002 } 1003 } 1004 1005 Exit: 1006 return error; 1007 } 1008 1009 1010 /* Link segments to form stems and serifs. */ 1011 1012 FT_LOCAL_DEF( void ) 1013 af_latin_hints_link_segments( AF_GlyphHints hints, 1014 AF_Dimension dim ) 1015 { 1016 AF_AxisHints axis = &hints->axis[dim]; 1017 AF_Segment segments = axis->segments; 1018 AF_Segment segment_limit = segments + axis->num_segments; 1019 FT_Pos len_threshold, len_score; 1020 AF_Segment seg1, seg2; 1021 1022 1023 len_threshold = AF_LATIN_CONSTANT( hints->metrics, 8 ); 1024 if ( len_threshold == 0 ) 1025 len_threshold = 1; 1026 1027 len_score = AF_LATIN_CONSTANT( hints->metrics, 6000 ); 1028 1029 /* now compare each segment to the others */ 1030 for ( seg1 = segments; seg1 < segment_limit; seg1++ ) 1031 { 1032 /* the fake segments are introduced to hint the metrics -- */ 1033 /* we must never link them to anything */ 1034 if ( seg1->dir != axis->major_dir || seg1->first == seg1->last ) 1035 continue; 1036 1037 /* search for stems having opposite directions, */ 1038 /* with seg1 to the `left' of seg2 */ 1039 for ( seg2 = segments; seg2 < segment_limit; seg2++ ) 1040 { 1041 FT_Pos pos1 = seg1->pos; 1042 FT_Pos pos2 = seg2->pos; 1043 1044 1045 if ( seg1->dir + seg2->dir == 0 && pos2 > pos1 ) 1046 { 1047 /* compute distance between the two segments */ 1048 FT_Pos dist = pos2 - pos1; 1049 FT_Pos min = seg1->min_coord; 1050 FT_Pos max = seg1->max_coord; 1051 FT_Pos len, score; 1052 1053 1054 if ( min < seg2->min_coord ) 1055 min = seg2->min_coord; 1056 1057 if ( max > seg2->max_coord ) 1058 max = seg2->max_coord; 1059 1060 /* compute maximum coordinate difference of the two segments */ 1061 len = max - min; 1062 if ( len >= len_threshold ) 1063 { 1064 /* small coordinate differences cause a higher score, and */ 1065 /* segments with a greater distance cause a higher score also */ 1066 score = dist + len_score / len; 1067 1068 /* and we search for the smallest score */ 1069 /* of the sum of the two values */ 1070 if ( score < seg1->score ) 1071 { 1072 seg1->score = score; 1073 seg1->link = seg2; 1074 } 1075 1076 if ( score < seg2->score ) 1077 { 1078 seg2->score = score; 1079 seg2->link = seg1; 1080 } 1081 } 1082 } 1083 } 1084 } 1085 1086 /* now compute the `serif' segments, cf. explanations in `afhints.h' */ 1087 for ( seg1 = segments; seg1 < segment_limit; seg1++ ) 1088 { 1089 seg2 = seg1->link; 1090 1091 if ( seg2 ) 1092 { 1093 if ( seg2->link != seg1 ) 1094 { 1095 seg1->link = 0; 1096 seg1->serif = seg2->link; 1097 } 1098 } 1099 } 1100 } 1101 1102 1103 /* Link segments to edges, using feature analysis for selection. */ 1104 1105 FT_LOCAL_DEF( FT_Error ) 1106 af_latin_hints_compute_edges( AF_GlyphHints hints, 1107 AF_Dimension dim ) 1108 { 1109 AF_AxisHints axis = &hints->axis[dim]; 1110 FT_Error error = FT_Err_Ok; 1111 FT_Memory memory = hints->memory; 1112 AF_LatinAxis laxis = &((AF_LatinMetrics)hints->metrics)->axis[dim]; 1113 1114 AF_Segment segments = axis->segments; 1115 AF_Segment segment_limit = segments + axis->num_segments; 1116 AF_Segment seg; 1117 1118 #if 0 1119 AF_Direction up_dir; 1120 #endif 1121 FT_Fixed scale; 1122 FT_Pos edge_distance_threshold; 1123 FT_Pos segment_length_threshold; 1124 1125 1126 axis->num_edges = 0; 1127 1128 scale = ( dim == AF_DIMENSION_HORZ ) ? hints->x_scale 1129 : hints->y_scale; 1130 1131 #if 0 1132 up_dir = ( dim == AF_DIMENSION_HORZ ) ? AF_DIR_UP 1133 : AF_DIR_RIGHT; 1134 #endif 1135 1136 /* 1137 * We ignore all segments that are less than 1 pixel in length 1138 * to avoid many problems with serif fonts. We compute the 1139 * corresponding threshold in font units. 1140 */ 1141 if ( dim == AF_DIMENSION_HORZ ) 1142 segment_length_threshold = FT_DivFix( 64, hints->y_scale ); 1143 else 1144 segment_length_threshold = 0; 1145 1146 /*********************************************************************/ 1147 /* */ 1148 /* We begin by generating a sorted table of edges for the current */ 1149 /* direction. To do so, we simply scan each segment and try to find */ 1150 /* an edge in our table that corresponds to its position. */ 1151 /* */ 1152 /* If no edge is found, we create and insert a new edge in the */ 1153 /* sorted table. Otherwise, we simply add the segment to the edge's */ 1154 /* list which gets processed in the second step to compute the */ 1155 /* edge's properties. */ 1156 /* */ 1157 /* Note that the table of edges is sorted along the segment/edge */ 1158 /* position. */ 1159 /* */ 1160 /*********************************************************************/ 1161 1162 /* assure that edge distance threshold is at most 0.25px */ 1163 edge_distance_threshold = FT_MulFix( laxis->edge_distance_threshold, 1164 scale ); 1165 if ( edge_distance_threshold > 64 / 4 ) 1166 edge_distance_threshold = 64 / 4; 1167 1168 edge_distance_threshold = FT_DivFix( edge_distance_threshold, 1169 scale ); 1170 1171 for ( seg = segments; seg < segment_limit; seg++ ) 1172 { 1173 AF_Edge found = NULL; 1174 FT_Int ee; 1175 1176 1177 if ( seg->height < segment_length_threshold ) 1178 continue; 1179 1180 /* A special case for serif edges: If they are smaller than */ 1181 /* 1.5 pixels we ignore them. */ 1182 if ( seg->serif && 1183 2 * seg->height < 3 * segment_length_threshold ) 1184 continue; 1185 1186 /* look for an edge corresponding to the segment */ 1187 for ( ee = 0; ee < axis->num_edges; ee++ ) 1188 { 1189 AF_Edge edge = axis->edges + ee; 1190 FT_Pos dist; 1191 1192 1193 dist = seg->pos - edge->fpos; 1194 if ( dist < 0 ) 1195 dist = -dist; 1196 1197 if ( dist < edge_distance_threshold && edge->dir == seg->dir ) 1198 { 1199 found = edge; 1200 break; 1201 } 1202 } 1203 1204 if ( !found ) 1205 { 1206 AF_Edge edge; 1207 1208 1209 /* insert a new edge in the list and */ 1210 /* sort according to the position */ 1211 error = af_axis_hints_new_edge( axis, seg->pos, 1212 (AF_Direction)seg->dir, 1213 memory, &edge ); 1214 if ( error ) 1215 goto Exit; 1216 1217 /* add the segment to the new edge's list */ 1218 FT_ZERO( edge ); 1219 1220 edge->first = seg; 1221 edge->last = seg; 1222 edge->dir = seg->dir; 1223 edge->fpos = seg->pos; 1224 edge->opos = FT_MulFix( seg->pos, scale ); 1225 edge->pos = edge->opos; 1226 seg->edge_next = seg; 1227 } 1228 else 1229 { 1230 /* if an edge was found, simply add the segment to the edge's */ 1231 /* list */ 1232 seg->edge_next = found->first; 1233 found->last->edge_next = seg; 1234 found->last = seg; 1235 } 1236 } 1237 1238 1239 /******************************************************************/ 1240 /* */ 1241 /* Good, we now compute each edge's properties according to the */ 1242 /* segments found on its position. Basically, these are */ 1243 /* */ 1244 /* - the edge's main direction */ 1245 /* - stem edge, serif edge or both (which defaults to stem then) */ 1246 /* - rounded edge, straight or both (which defaults to straight) */ 1247 /* - link for edge */ 1248 /* */ 1249 /******************************************************************/ 1250 1251 /* first of all, set the `edge' field in each segment -- this is */ 1252 /* required in order to compute edge links */ 1253 1254 /* 1255 * Note that removing this loop and setting the `edge' field of each 1256 * segment directly in the code above slows down execution speed for 1257 * some reasons on platforms like the Sun. 1258 */ 1259 { 1260 AF_Edge edges = axis->edges; 1261 AF_Edge edge_limit = edges + axis->num_edges; 1262 AF_Edge edge; 1263 1264 1265 for ( edge = edges; edge < edge_limit; edge++ ) 1266 { 1267 seg = edge->first; 1268 if ( seg ) 1269 do 1270 { 1271 seg->edge = edge; 1272 seg = seg->edge_next; 1273 1274 } while ( seg != edge->first ); 1275 } 1276 1277 /* now compute each edge properties */ 1278 for ( edge = edges; edge < edge_limit; edge++ ) 1279 { 1280 FT_Int is_round = 0; /* does it contain round segments? */ 1281 FT_Int is_straight = 0; /* does it contain straight segments? */ 1282 #if 0 1283 FT_Pos ups = 0; /* number of upwards segments */ 1284 FT_Pos downs = 0; /* number of downwards segments */ 1285 #endif 1286 1287 1288 seg = edge->first; 1289 1290 do 1291 { 1292 FT_Bool is_serif; 1293 1294 1295 /* check for roundness of segment */ 1296 if ( seg->flags & AF_EDGE_ROUND ) 1297 is_round++; 1298 else 1299 is_straight++; 1300 1301 #if 0 1302 /* check for segment direction */ 1303 if ( seg->dir == up_dir ) 1304 ups += seg->max_coord - seg->min_coord; 1305 else 1306 downs += seg->max_coord - seg->min_coord; 1307 #endif 1308 1309 /* check for links -- if seg->serif is set, then seg->link must */ 1310 /* be ignored */ 1311 is_serif = (FT_Bool)( seg->serif && 1312 seg->serif->edge && 1313 seg->serif->edge != edge ); 1314 1315 if ( ( seg->link && seg->link->edge != NULL ) || is_serif ) 1316 { 1317 AF_Edge edge2; 1318 AF_Segment seg2; 1319 1320 1321 edge2 = edge->link; 1322 seg2 = seg->link; 1323 1324 if ( is_serif ) 1325 { 1326 seg2 = seg->serif; 1327 edge2 = edge->serif; 1328 } 1329 1330 if ( edge2 ) 1331 { 1332 FT_Pos edge_delta; 1333 FT_Pos seg_delta; 1334 1335 1336 edge_delta = edge->fpos - edge2->fpos; 1337 if ( edge_delta < 0 ) 1338 edge_delta = -edge_delta; 1339 1340 seg_delta = seg->pos - seg2->pos; 1341 if ( seg_delta < 0 ) 1342 seg_delta = -seg_delta; 1343 1344 if ( seg_delta < edge_delta ) 1345 edge2 = seg2->edge; 1346 } 1347 else 1348 edge2 = seg2->edge; 1349 1350 if ( is_serif ) 1351 { 1352 edge->serif = edge2; 1353 edge2->flags |= AF_EDGE_SERIF; 1354 } 1355 else 1356 edge->link = edge2; 1357 } 1358 1359 seg = seg->edge_next; 1360 1361 } while ( seg != edge->first ); 1362 1363 /* set the round/straight flags */ 1364 edge->flags = AF_EDGE_NORMAL; 1365 1366 if ( is_round > 0 && is_round >= is_straight ) 1367 edge->flags |= AF_EDGE_ROUND; 1368 1369 #if 0 1370 /* set the edge's main direction */ 1371 edge->dir = AF_DIR_NONE; 1372 1373 if ( ups > downs ) 1374 edge->dir = (FT_Char)up_dir; 1375 1376 else if ( ups < downs ) 1377 edge->dir = (FT_Char)-up_dir; 1378 1379 else if ( ups == downs ) 1380 edge->dir = 0; /* both up and down! */ 1381 #endif 1382 1383 /* get rid of serifs if link is set */ 1384 /* XXX: This gets rid of many unpleasant artefacts! */ 1385 /* Example: the `c' in cour.pfa at size 13 */ 1386 1387 if ( edge->serif && edge->link ) 1388 edge->serif = 0; 1389 } 1390 } 1391 1392 Exit: 1393 return error; 1394 } 1395 1396 1397 /* Detect segments and edges for given dimension. */ 1398 1399 FT_LOCAL_DEF( FT_Error ) 1400 af_latin_hints_detect_features( AF_GlyphHints hints, 1401 AF_Dimension dim ) 1402 { 1403 FT_Error error; 1404 1405 1406 error = af_latin_hints_compute_segments( hints, dim ); 1407 if ( !error ) 1408 { 1409 af_latin_hints_link_segments( hints, dim ); 1410 1411 error = af_latin_hints_compute_edges( hints, dim ); 1412 } 1413 1414 return error; 1415 } 1416 1417 1418 /* Compute all edges which lie within blue zones. */ 1419 1420 FT_LOCAL_DEF( void ) 1421 af_latin_hints_compute_blue_edges( AF_GlyphHints hints, 1422 AF_LatinMetrics metrics ) 1423 { 1424 AF_AxisHints axis = &hints->axis[AF_DIMENSION_VERT]; 1425 AF_Edge edge = axis->edges; 1426 AF_Edge edge_limit = edge + axis->num_edges; 1427 AF_LatinAxis latin = &metrics->axis[AF_DIMENSION_VERT]; 1428 FT_Fixed scale = latin->scale; 1429 1430 1431 /* compute which blue zones are active, i.e. have their scaled */ 1432 /* size < 3/4 pixels */ 1433 1434 /* for each horizontal edge search the blue zone which is closest */ 1435 for ( ; edge < edge_limit; edge++ ) 1436 { 1437 FT_UInt bb; 1438 AF_Width best_blue = NULL; 1439 FT_Pos best_dist; /* initial threshold */ 1440 1441 1442 /* compute the initial threshold as a fraction of the EM size */ 1443 /* (the value 40 is heuristic) */ 1444 best_dist = FT_MulFix( metrics->units_per_em / 40, scale ); 1445 1446 /* assure a minimum distance of 0.5px */ 1447 if ( best_dist > 64 / 2 ) 1448 best_dist = 64 / 2; 1449 1450 for ( bb = 0; bb < latin->blue_count; bb++ ) 1451 { 1452 AF_LatinBlue blue = latin->blues + bb; 1453 FT_Bool is_top_blue, is_major_dir; 1454 1455 1456 /* skip inactive blue zones (i.e., those that are too large) */ 1457 if ( !( blue->flags & AF_LATIN_BLUE_ACTIVE ) ) 1458 continue; 1459 1460 /* if it is a top zone, check for right edges -- if it is a bottom */ 1461 /* zone, check for left edges */ 1462 /* */ 1463 /* of course, that's for TrueType */ 1464 is_top_blue = (FT_Byte)( ( blue->flags & AF_LATIN_BLUE_TOP ) != 0 ); 1465 is_major_dir = FT_BOOL( edge->dir == axis->major_dir ); 1466 1467 /* if it is a top zone, the edge must be against the major */ 1468 /* direction; if it is a bottom zone, it must be in the major */ 1469 /* direction */ 1470 if ( is_top_blue ^ is_major_dir ) 1471 { 1472 FT_Pos dist; 1473 1474 1475 /* first of all, compare it to the reference position */ 1476 dist = edge->fpos - blue->ref.org; 1477 if ( dist < 0 ) 1478 dist = -dist; 1479 1480 dist = FT_MulFix( dist, scale ); 1481 if ( dist < best_dist ) 1482 { 1483 best_dist = dist; 1484 best_blue = &blue->ref; 1485 } 1486 1487 /* now compare it to the overshoot position and check whether */ 1488 /* the edge is rounded, and whether the edge is over the */ 1489 /* reference position of a top zone, or under the reference */ 1490 /* position of a bottom zone */ 1491 if ( edge->flags & AF_EDGE_ROUND && dist != 0 ) 1492 { 1493 FT_Bool is_under_ref = FT_BOOL( edge->fpos < blue->ref.org ); 1494 1495 1496 if ( is_top_blue ^ is_under_ref ) 1497 { 1498 dist = edge->fpos - blue->shoot.org; 1499 if ( dist < 0 ) 1500 dist = -dist; 1501 1502 dist = FT_MulFix( dist, scale ); 1503 if ( dist < best_dist ) 1504 { 1505 best_dist = dist; 1506 best_blue = &blue->shoot; 1507 } 1508 } 1509 } 1510 } 1511 } 1512 1513 if ( best_blue ) 1514 edge->blue_edge = best_blue; 1515 } 1516 } 1517 1518 1519 /* Initalize hinting engine. */ 1520 1521 static FT_Error 1522 af_latin_hints_init( AF_GlyphHints hints, 1523 AF_LatinMetrics metrics ) 1524 { 1525 FT_Render_Mode mode; 1526 FT_UInt32 scaler_flags, other_flags; 1527 FT_Face face = metrics->root.scaler.face; 1528 1529 1530 af_glyph_hints_rescale( hints, (AF_ScriptMetrics)metrics ); 1531 1532 /* 1533 * correct x_scale and y_scale if needed, since they may have 1534 * been modified by `af_latin_metrics_scale_dim' above 1535 */ 1536 hints->x_scale = metrics->axis[AF_DIMENSION_HORZ].scale; 1537 hints->x_delta = metrics->axis[AF_DIMENSION_HORZ].delta; 1538 hints->y_scale = metrics->axis[AF_DIMENSION_VERT].scale; 1539 hints->y_delta = metrics->axis[AF_DIMENSION_VERT].delta; 1540 1541 /* compute flags depending on render mode, etc. */ 1542 mode = metrics->root.scaler.render_mode; 1543 1544 #if 0 /* #ifdef AF_CONFIG_OPTION_USE_WARPER */ 1545 if ( mode == FT_RENDER_MODE_LCD || mode == FT_RENDER_MODE_LCD_V ) 1546 metrics->root.scaler.render_mode = mode = FT_RENDER_MODE_NORMAL; 1547 #endif 1548 1549 scaler_flags = hints->scaler_flags; 1550 other_flags = 0; 1551 1552 /* 1553 * We snap the width of vertical stems for the monochrome and 1554 * horizontal LCD rendering targets only. 1555 */ 1556 if ( mode == FT_RENDER_MODE_MONO || mode == FT_RENDER_MODE_LCD ) 1557 other_flags |= AF_LATIN_HINTS_HORZ_SNAP; 1558 1559 /* 1560 * We snap the width of horizontal stems for the monochrome and 1561 * vertical LCD rendering targets only. 1562 */ 1563 if ( mode == FT_RENDER_MODE_MONO || mode == FT_RENDER_MODE_LCD_V ) 1564 other_flags |= AF_LATIN_HINTS_VERT_SNAP; 1565 1566 /* 1567 * We adjust stems to full pixels only if we don't use the `light' mode. 1568 */ 1569 if ( mode != FT_RENDER_MODE_LIGHT ) 1570 other_flags |= AF_LATIN_HINTS_STEM_ADJUST; 1571 1572 if ( mode == FT_RENDER_MODE_MONO ) 1573 other_flags |= AF_LATIN_HINTS_MONO; 1574 1575 /* 1576 * In `light' hinting mode we disable horizontal hinting completely. 1577 * We also do it if the face is italic. 1578 */ 1579 if ( mode == FT_RENDER_MODE_LIGHT || 1580 ( face->style_flags & FT_STYLE_FLAG_ITALIC ) != 0 ) 1581 scaler_flags |= AF_SCALER_FLAG_NO_HORIZONTAL; 1582 1583 hints->scaler_flags = scaler_flags; 1584 hints->other_flags = other_flags; 1585 1586 return FT_Err_Ok; 1587 } 1588 1589 1590 /*************************************************************************/ 1591 /*************************************************************************/ 1592 /***** *****/ 1593 /***** L A T I N G L Y P H G R I D - F I T T I N G *****/ 1594 /***** *****/ 1595 /*************************************************************************/ 1596 /*************************************************************************/ 1597 1598 /* Snap a given width in scaled coordinates to one of the */ 1599 /* current standard widths. */ 1600 1601 static FT_Pos 1602 af_latin_snap_width( AF_Width widths, 1603 FT_Int count, 1604 FT_Pos width ) 1605 { 1606 int n; 1607 FT_Pos best = 64 + 32 + 2; 1608 FT_Pos reference = width; 1609 FT_Pos scaled; 1610 1611 1612 for ( n = 0; n < count; n++ ) 1613 { 1614 FT_Pos w; 1615 FT_Pos dist; 1616 1617 1618 w = widths[n].cur; 1619 dist = width - w; 1620 if ( dist < 0 ) 1621 dist = -dist; 1622 if ( dist < best ) 1623 { 1624 best = dist; 1625 reference = w; 1626 } 1627 } 1628 1629 scaled = FT_PIX_ROUND( reference ); 1630 1631 if ( width >= reference ) 1632 { 1633 if ( width < scaled + 48 ) 1634 width = reference; 1635 } 1636 else 1637 { 1638 if ( width > scaled - 48 ) 1639 width = reference; 1640 } 1641 1642 return width; 1643 } 1644 1645 1646 /* Compute the snapped width of a given stem, ignoring very thin ones. */ 1647 /* There is a lot of voodoo in this function; changing the hard-coded */ 1648 /* parameters influence the whole hinting process. */ 1649 1650 static FT_Pos 1651 af_latin_compute_stem_width( AF_GlyphHints hints, 1652 AF_Dimension dim, 1653 FT_Pos width, 1654 AF_Edge_Flags base_flags, 1655 AF_Edge_Flags stem_flags ) 1656 { 1657 AF_LatinMetrics metrics = (AF_LatinMetrics) hints->metrics; 1658 AF_LatinAxis axis = & metrics->axis[dim]; 1659 FT_Pos dist = width; 1660 FT_Int sign = 0; 1661 FT_Int vertical = ( dim == AF_DIMENSION_VERT ); 1662 1663 1664 if ( !AF_LATIN_HINTS_DO_STEM_ADJUST( hints ) || 1665 axis->extra_light ) 1666 return width; 1667 1668 if ( dist < 0 ) 1669 { 1670 dist = -width; 1671 sign = 1; 1672 } 1673 1674 if ( ( vertical && !AF_LATIN_HINTS_DO_VERT_SNAP( hints ) ) || 1675 ( !vertical && !AF_LATIN_HINTS_DO_HORZ_SNAP( hints ) ) ) 1676 { 1677 /* smooth hinting process: very lightly quantize the stem width */ 1678 1679 /* leave the widths of serifs alone */ 1680 if ( ( stem_flags & AF_EDGE_SERIF ) && 1681 vertical && 1682 ( dist < 3 * 64 ) ) 1683 goto Done_Width; 1684 1685 else if ( base_flags & AF_EDGE_ROUND ) 1686 { 1687 if ( dist < 80 ) 1688 dist = 64; 1689 } 1690 else if ( dist < 56 ) 1691 dist = 56; 1692 1693 if ( axis->width_count > 0 ) 1694 { 1695 FT_Pos delta; 1696 1697 1698 /* compare to standard width */ 1699 delta = dist - axis->widths[0].cur; 1700 1701 if ( delta < 0 ) 1702 delta = -delta; 1703 1704 if ( delta < 40 ) 1705 { 1706 dist = axis->widths[0].cur; 1707 if ( dist < 48 ) 1708 dist = 48; 1709 1710 goto Done_Width; 1711 } 1712 1713 if ( dist < 3 * 64 ) 1714 { 1715 delta = dist & 63; 1716 dist &= -64; 1717 1718 if ( delta < 10 ) 1719 dist += delta; 1720 1721 else if ( delta < 32 ) 1722 dist += 10; 1723 1724 else if ( delta < 54 ) 1725 dist += 54; 1726 1727 else 1728 dist += delta; 1729 } 1730 else 1731 dist = ( dist + 32 ) & ~63; 1732 } 1733 } 1734 else 1735 { 1736 /* strong hinting process: snap the stem width to integer pixels */ 1737 1738 FT_Pos org_dist = dist; 1739 1740 1741 dist = af_latin_snap_width( axis->widths, axis->width_count, dist ); 1742 1743 if ( vertical ) 1744 { 1745 /* in the case of vertical hinting, always round */ 1746 /* the stem heights to integer pixels */ 1747 1748 if ( dist >= 64 ) 1749 dist = ( dist + 16 ) & ~63; 1750 else 1751 dist = 64; 1752 } 1753 else 1754 { 1755 if ( AF_LATIN_HINTS_DO_MONO( hints ) ) 1756 { 1757 /* monochrome horizontal hinting: snap widths to integer pixels */ 1758 /* with a different threshold */ 1759 1760 if ( dist < 64 ) 1761 dist = 64; 1762 else 1763 dist = ( dist + 32 ) & ~63; 1764 } 1765 else 1766 { 1767 /* for horizontal anti-aliased hinting, we adopt a more subtle */ 1768 /* approach: we strengthen small stems, round stems whose size */ 1769 /* is between 1 and 2 pixels to an integer, otherwise nothing */ 1770 1771 if ( dist < 48 ) 1772 dist = ( dist + 64 ) >> 1; 1773 1774 else if ( dist < 128 ) 1775 { 1776 /* We only round to an integer width if the corresponding */ 1777 /* distortion is less than 1/4 pixel. Otherwise this */ 1778 /* makes everything worse since the diagonals, which are */ 1779 /* not hinted, appear a lot bolder or thinner than the */ 1780 /* vertical stems. */ 1781 1782 FT_Pos delta; 1783 1784 1785 dist = ( dist + 22 ) & ~63; 1786 delta = dist - org_dist; 1787 if ( delta < 0 ) 1788 delta = -delta; 1789 1790 if ( delta >= 16 ) 1791 { 1792 dist = org_dist; 1793 if ( dist < 48 ) 1794 dist = ( dist + 64 ) >> 1; 1795 } 1796 } 1797 else 1798 /* round otherwise to prevent color fringes in LCD mode */ 1799 dist = ( dist + 32 ) & ~63; 1800 } 1801 } 1802 } 1803 1804 Done_Width: 1805 if ( sign ) 1806 dist = -dist; 1807 1808 return dist; 1809 } 1810 1811 1812 /* Align one stem edge relative to the previous stem edge. */ 1813 1814 static void 1815 af_latin_align_linked_edge( AF_GlyphHints hints, 1816 AF_Dimension dim, 1817 AF_Edge base_edge, 1818 AF_Edge stem_edge ) 1819 { 1820 FT_Pos dist = stem_edge->opos - base_edge->opos; 1821 1822 FT_Pos fitted_width = af_latin_compute_stem_width( 1823 hints, dim, dist, 1824 (AF_Edge_Flags)base_edge->flags, 1825 (AF_Edge_Flags)stem_edge->flags ); 1826 1827 1828 stem_edge->pos = base_edge->pos + fitted_width; 1829 1830 FT_TRACE5(( " LINK: edge %d (opos=%.2f) linked to %.2f," 1831 " dist was %.2f, now %.2f\n", 1832 stem_edge-hints->axis[dim].edges, stem_edge->opos / 64.0, 1833 stem_edge->pos / 64.0, dist / 64.0, fitted_width / 64.0 )); 1834 } 1835 1836 1837 /* Shift the coordinates of the `serif' edge by the same amount */ 1838 /* as the corresponding `base' edge has been moved already. */ 1839 1840 static void 1841 af_latin_align_serif_edge( AF_GlyphHints hints, 1842 AF_Edge base, 1843 AF_Edge serif ) 1844 { 1845 FT_UNUSED( hints ); 1846 1847 serif->pos = base->pos + ( serif->opos - base->opos ); 1848 } 1849 1850 1851 /*************************************************************************/ 1852 /*************************************************************************/ 1853 /*************************************************************************/ 1854 /**** ****/ 1855 /**** E D G E H I N T I N G ****/ 1856 /**** ****/ 1857 /*************************************************************************/ 1858 /*************************************************************************/ 1859 /*************************************************************************/ 1860 1861 1862 /* The main grid-fitting routine. */ 1863 1864 FT_LOCAL_DEF( void ) 1865 af_latin_hint_edges( AF_GlyphHints hints, 1866 AF_Dimension dim ) 1867 { 1868 AF_AxisHints axis = &hints->axis[dim]; 1869 AF_Edge edges = axis->edges; 1870 AF_Edge edge_limit = edges + axis->num_edges; 1871 FT_PtrDist n_edges; 1872 AF_Edge edge; 1873 AF_Edge anchor = NULL; 1874 FT_Int has_serifs = 0; 1875 1876 #ifdef FT_DEBUG_LEVEL_TRACE 1877 FT_UInt num_actions = 0; 1878 #endif 1879 1880 1881 FT_TRACE5(( "%s edge hinting\n", 1882 dim == AF_DIMENSION_VERT ? "horizontal" : "vertical" )); 1883 1884 /* we begin by aligning all stems relative to the blue zone */ 1885 /* if needed -- that's only for horizontal edges */ 1886 1887 if ( dim == AF_DIMENSION_VERT && AF_HINTS_DO_BLUES( hints ) ) 1888 { 1889 for ( edge = edges; edge < edge_limit; edge++ ) 1890 { 1891 AF_Width blue; 1892 AF_Edge edge1, edge2; /* these edges form the stem to check */ 1893 1894 1895 if ( edge->flags & AF_EDGE_DONE ) 1896 continue; 1897 1898 blue = edge->blue_edge; 1899 edge1 = NULL; 1900 edge2 = edge->link; 1901 1902 if ( blue ) 1903 edge1 = edge; 1904 1905 /* flip edges if the other stem is aligned to a blue zone */ 1906 else if ( edge2 && edge2->blue_edge ) 1907 { 1908 blue = edge2->blue_edge; 1909 edge1 = edge2; 1910 edge2 = edge; 1911 } 1912 1913 if ( !edge1 ) 1914 continue; 1915 1916 #ifdef FT_DEBUG_LEVEL_TRACE 1917 if ( !anchor ) 1918 FT_TRACE5(( " BLUE_ANCHOR: edge %d (opos=%.2f) snapped to %.2f," 1919 " was %.2f (anchor=edge %d)\n", 1920 edge1 - edges, edge1->opos / 64.0, blue->fit / 64.0, 1921 edge1->pos / 64.0, edge - edges )); 1922 else 1923 FT_TRACE5(( " BLUE: edge %d (opos=%.2f) snapped to %.2f," 1924 " was %.2f\n", 1925 edge1 - edges, edge1->opos / 64.0, blue->fit / 64.0, 1926 edge1->pos / 64.0 )); 1927 1928 num_actions++; 1929 #endif 1930 1931 edge1->pos = blue->fit; 1932 edge1->flags |= AF_EDGE_DONE; 1933 1934 if ( edge2 && !edge2->blue_edge ) 1935 { 1936 af_latin_align_linked_edge( hints, dim, edge1, edge2 ); 1937 edge2->flags |= AF_EDGE_DONE; 1938 1939 #ifdef FT_DEBUG_LEVEL_TRACE 1940 num_actions++; 1941 #endif 1942 } 1943 1944 if ( !anchor ) 1945 anchor = edge; 1946 } 1947 } 1948 1949 /* now we align all other stem edges, trying to maintain the */ 1950 /* relative order of stems in the glyph */ 1951 for ( edge = edges; edge < edge_limit; edge++ ) 1952 { 1953 AF_Edge edge2; 1954 1955 1956 if ( edge->flags & AF_EDGE_DONE ) 1957 continue; 1958 1959 /* skip all non-stem edges */ 1960 edge2 = edge->link; 1961 if ( !edge2 ) 1962 { 1963 has_serifs++; 1964 continue; 1965 } 1966 1967 /* now align the stem */ 1968 1969 /* this should not happen, but it's better to be safe */ 1970 if ( edge2->blue_edge ) 1971 { 1972 FT_TRACE5(( " ASSERTION FAILED for edge %d\n", edge2-edges )); 1973 1974 af_latin_align_linked_edge( hints, dim, edge2, edge ); 1975 edge->flags |= AF_EDGE_DONE; 1976 1977 #ifdef FT_DEBUG_LEVEL_TRACE 1978 num_actions++; 1979 #endif 1980 continue; 1981 } 1982 1983 if ( !anchor ) 1984 { 1985 /* if we reach this if clause, no stem has been aligned yet */ 1986 1987 FT_Pos org_len, org_center, cur_len; 1988 FT_Pos cur_pos1, error1, error2, u_off, d_off; 1989 1990 1991 org_len = edge2->opos - edge->opos; 1992 cur_len = af_latin_compute_stem_width( 1993 hints, dim, org_len, 1994 (AF_Edge_Flags)edge->flags, 1995 (AF_Edge_Flags)edge2->flags ); 1996 1997 /* some voodoo to specially round edges for small stem widths; */ 1998 /* the idea is to align the center of a stem, then shifting */ 1999 /* the stem edges to suitable positions */ 2000 if ( cur_len <= 64 ) 2001 { 2002 /* width <= 1px */ 2003 u_off = 32; 2004 d_off = 32; 2005 } 2006 else 2007 { 2008 /* 1px < width < 1.5px */ 2009 u_off = 38; 2010 d_off = 26; 2011 } 2012 2013 if ( cur_len < 96 ) 2014 { 2015 org_center = edge->opos + ( org_len >> 1 ); 2016 cur_pos1 = FT_PIX_ROUND( org_center ); 2017 2018 error1 = org_center - ( cur_pos1 - u_off ); 2019 if ( error1 < 0 ) 2020 error1 = -error1; 2021 2022 error2 = org_center - ( cur_pos1 + d_off ); 2023 if ( error2 < 0 ) 2024 error2 = -error2; 2025 2026 if ( error1 < error2 ) 2027 cur_pos1 -= u_off; 2028 else 2029 cur_pos1 += d_off; 2030 2031 edge->pos = cur_pos1 - cur_len / 2; 2032 edge2->pos = edge->pos + cur_len; 2033 } 2034 else 2035 edge->pos = FT_PIX_ROUND( edge->opos ); 2036 2037 anchor = edge; 2038 edge->flags |= AF_EDGE_DONE; 2039 2040 FT_TRACE5(( " ANCHOR: edge %d (opos=%.2f) and %d (opos=%.2f)" 2041 " snapped to %.2f and %.2f\n", 2042 edge - edges, edge->opos / 64.0, 2043 edge2 - edges, edge2->opos / 64.0, 2044 edge->pos / 64.0, edge2->pos / 64.0 )); 2045 2046 af_latin_align_linked_edge( hints, dim, edge, edge2 ); 2047 2048 #ifdef FT_DEBUG_LEVEL_TRACE 2049 num_actions += 2; 2050 #endif 2051 } 2052 else 2053 { 2054 FT_Pos org_pos, org_len, org_center, cur_len; 2055 FT_Pos cur_pos1, cur_pos2, delta1, delta2; 2056 2057 2058 org_pos = anchor->pos + ( edge->opos - anchor->opos ); 2059 org_len = edge2->opos - edge->opos; 2060 org_center = org_pos + ( org_len >> 1 ); 2061 2062 cur_len = af_latin_compute_stem_width( 2063 hints, dim, org_len, 2064 (AF_Edge_Flags)edge->flags, 2065 (AF_Edge_Flags)edge2->flags ); 2066 2067 if ( edge2->flags & AF_EDGE_DONE ) 2068 { 2069 FT_TRACE5(( " ADJUST: edge %d (pos=%.2f) moved to %.2f\n", 2070 edge - edges, edge->pos / 64.0, 2071 ( edge2->pos - cur_len ) / 64.0 )); 2072 2073 edge->pos = edge2->pos - cur_len; 2074 } 2075 2076 else if ( cur_len < 96 ) 2077 { 2078 FT_Pos u_off, d_off; 2079 2080 2081 cur_pos1 = FT_PIX_ROUND( org_center ); 2082 2083 if ( cur_len <= 64 ) 2084 { 2085 u_off = 32; 2086 d_off = 32; 2087 } 2088 else 2089 { 2090 u_off = 38; 2091 d_off = 26; 2092 } 2093 2094 delta1 = org_center - ( cur_pos1 - u_off ); 2095 if ( delta1 < 0 ) 2096 delta1 = -delta1; 2097 2098 delta2 = org_center - ( cur_pos1 + d_off ); 2099 if ( delta2 < 0 ) 2100 delta2 = -delta2; 2101 2102 if ( delta1 < delta2 ) 2103 cur_pos1 -= u_off; 2104 else 2105 cur_pos1 += d_off; 2106 2107 edge->pos = cur_pos1 - cur_len / 2; 2108 edge2->pos = cur_pos1 + cur_len / 2; 2109 2110 FT_TRACE5(( " STEM: edge %d (opos=%.2f) linked to %d (opos=%.2f)" 2111 " snapped to %.2f and %.2f\n", 2112 edge - edges, edge->opos / 64.0, 2113 edge2 - edges, edge2->opos / 64.0, 2114 edge->pos / 64.0, edge2->pos / 64.0 )); 2115 } 2116 2117 else 2118 { 2119 org_pos = anchor->pos + ( edge->opos - anchor->opos ); 2120 org_len = edge2->opos - edge->opos; 2121 org_center = org_pos + ( org_len >> 1 ); 2122 2123 cur_len = af_latin_compute_stem_width( 2124 hints, dim, org_len, 2125 (AF_Edge_Flags)edge->flags, 2126 (AF_Edge_Flags)edge2->flags ); 2127 2128 cur_pos1 = FT_PIX_ROUND( org_pos ); 2129 delta1 = cur_pos1 + ( cur_len >> 1 ) - org_center; 2130 if ( delta1 < 0 ) 2131 delta1 = -delta1; 2132 2133 cur_pos2 = FT_PIX_ROUND( org_pos + org_len ) - cur_len; 2134 delta2 = cur_pos2 + ( cur_len >> 1 ) - org_center; 2135 if ( delta2 < 0 ) 2136 delta2 = -delta2; 2137 2138 edge->pos = ( delta1 < delta2 ) ? cur_pos1 : cur_pos2; 2139 edge2->pos = edge->pos + cur_len; 2140 2141 FT_TRACE5(( " STEM: edge %d (opos=%.2f) linked to %d (opos=%.2f)" 2142 " snapped to %.2f and %.2f\n", 2143 edge - edges, edge->opos / 64.0, 2144 edge2 - edges, edge2->opos / 64.0, 2145 edge->pos / 64.0, edge2->pos / 64.0 )); 2146 } 2147 2148 #ifdef FT_DEBUG_LEVEL_TRACE 2149 num_actions++; 2150 #endif 2151 2152 edge->flags |= AF_EDGE_DONE; 2153 edge2->flags |= AF_EDGE_DONE; 2154 2155 if ( edge > edges && edge->pos < edge[-1].pos ) 2156 { 2157 #ifdef FT_DEBUG_LEVEL_TRACE 2158 FT_TRACE5(( " BOUND: edge %d (pos=%.2f) moved to %.2f\n", 2159 edge - edges, edge->pos / 64.0, edge[-1].pos / 64.0 )); 2160 2161 num_actions++; 2162 #endif 2163 2164 edge->pos = edge[-1].pos; 2165 } 2166 } 2167 } 2168 2169 /* make sure that lowercase m's maintain their symmetry */ 2170 2171 /* In general, lowercase m's have six vertical edges if they are sans */ 2172 /* serif, or twelve if they are with serifs. This implementation is */ 2173 /* based on that assumption, and seems to work very well with most */ 2174 /* faces. However, if for a certain face this assumption is not */ 2175 /* true, the m is just rendered like before. In addition, any stem */ 2176 /* correction will only be applied to symmetrical glyphs (even if the */ 2177 /* glyph is not an m), so the potential for unwanted distortion is */ 2178 /* relatively low. */ 2179 2180 /* We don't handle horizontal edges since we can't easily assure that */ 2181 /* the third (lowest) stem aligns with the base line; it might end up */ 2182 /* one pixel higher or lower. */ 2183 2184 n_edges = edge_limit - edges; 2185 if ( dim == AF_DIMENSION_HORZ && ( n_edges == 6 || n_edges == 12 ) ) 2186 { 2187 AF_Edge edge1, edge2, edge3; 2188 FT_Pos dist1, dist2, span, delta; 2189 2190 2191 if ( n_edges == 6 ) 2192 { 2193 edge1 = edges; 2194 edge2 = edges + 2; 2195 edge3 = edges + 4; 2196 } 2197 else 2198 { 2199 edge1 = edges + 1; 2200 edge2 = edges + 5; 2201 edge3 = edges + 9; 2202 } 2203 2204 dist1 = edge2->opos - edge1->opos; 2205 dist2 = edge3->opos - edge2->opos; 2206 2207 span = dist1 - dist2; 2208 if ( span < 0 ) 2209 span = -span; 2210 2211 if ( span < 8 ) 2212 { 2213 delta = edge3->pos - ( 2 * edge2->pos - edge1->pos ); 2214 edge3->pos -= delta; 2215 if ( edge3->link ) 2216 edge3->link->pos -= delta; 2217 2218 /* move the serifs along with the stem */ 2219 if ( n_edges == 12 ) 2220 { 2221 ( edges + 8 )->pos -= delta; 2222 ( edges + 11 )->pos -= delta; 2223 } 2224 2225 edge3->flags |= AF_EDGE_DONE; 2226 if ( edge3->link ) 2227 edge3->link->flags |= AF_EDGE_DONE; 2228 } 2229 } 2230 2231 if ( has_serifs || !anchor ) 2232 { 2233 /* 2234 * now hint the remaining edges (serifs and single) in order 2235 * to complete our processing 2236 */ 2237 for ( edge = edges; edge < edge_limit; edge++ ) 2238 { 2239 FT_Pos delta; 2240 2241 2242 if ( edge->flags & AF_EDGE_DONE ) 2243 continue; 2244 2245 delta = 1000; 2246 2247 if ( edge->serif ) 2248 { 2249 delta = edge->serif->opos - edge->opos; 2250 if ( delta < 0 ) 2251 delta = -delta; 2252 } 2253 2254 if ( delta < 64 + 16 ) 2255 { 2256 af_latin_align_serif_edge( hints, edge->serif, edge ); 2257 FT_TRACE5(( " SERIF: edge %d (opos=%.2f) serif to %d (opos=%.2f)" 2258 " aligned to %.2f\n", 2259 edge - edges, edge->opos / 64.0, 2260 edge->serif - edges, edge->serif->opos / 64.0, 2261 edge->pos / 64.0 )); 2262 } 2263 else if ( !anchor ) 2264 { 2265 edge->pos = FT_PIX_ROUND( edge->opos ); 2266 anchor = edge; 2267 FT_TRACE5(( " SERIF_ANCHOR: edge %d (opos=%.2f)" 2268 " snapped to %.2f\n", 2269 edge-edges, edge->opos / 64.0, edge->pos / 64.0 )); 2270 } 2271 else 2272 { 2273 AF_Edge before, after; 2274 2275 2276 for ( before = edge - 1; before >= edges; before-- ) 2277 if ( before->flags & AF_EDGE_DONE ) 2278 break; 2279 2280 for ( after = edge + 1; after < edge_limit; after++ ) 2281 if ( after->flags & AF_EDGE_DONE ) 2282 break; 2283 2284 if ( before >= edges && before < edge && 2285 after < edge_limit && after > edge ) 2286 { 2287 if ( after->opos == before->opos ) 2288 edge->pos = before->pos; 2289 else 2290 edge->pos = before->pos + 2291 FT_MulDiv( edge->opos - before->opos, 2292 after->pos - before->pos, 2293 after->opos - before->opos ); 2294 2295 FT_TRACE5(( " SERIF_LINK1: edge %d (opos=%.2f) snapped to %.2f" 2296 " from %d (opos=%.2f)\n", 2297 edge - edges, edge->opos / 64.0, 2298 edge->pos / 64.0, 2299 before - edges, before->opos / 64.0 )); 2300 } 2301 else 2302 { 2303 edge->pos = anchor->pos + 2304 ( ( edge->opos - anchor->opos + 16 ) & ~31 ); 2305 FT_TRACE5(( " SERIF_LINK2: edge %d (opos=%.2f)" 2306 " snapped to %.2f\n", 2307 edge - edges, edge->opos / 64.0, edge->pos / 64.0 )); 2308 } 2309 } 2310 2311 #ifdef FT_DEBUG_LEVEL_TRACE 2312 num_actions++; 2313 #endif 2314 edge->flags |= AF_EDGE_DONE; 2315 2316 if ( edge > edges && edge->pos < edge[-1].pos ) 2317 { 2318 #ifdef FT_DEBUG_LEVEL_TRACE 2319 FT_TRACE5(( " BOUND: edge %d (pos=%.2f) moved to %.2f\n", 2320 edge - edges, edge->pos / 64.0, edge[-1].pos / 64.0 )); 2321 2322 num_actions++; 2323 #endif 2324 edge->pos = edge[-1].pos; 2325 } 2326 2327 if ( edge + 1 < edge_limit && 2328 edge[1].flags & AF_EDGE_DONE && 2329 edge->pos > edge[1].pos ) 2330 { 2331 #ifdef FT_DEBUG_LEVEL_TRACE 2332 FT_TRACE5(( " BOUND: edge %d (pos=%.2f) moved to %.2f\n", 2333 edge - edges, edge->pos / 64.0, edge[1].pos / 64.0 )); 2334 2335 num_actions++; 2336 #endif 2337 2338 edge->pos = edge[1].pos; 2339 } 2340 } 2341 } 2342 2343 #ifdef FT_DEBUG_LEVEL_TRACE 2344 if ( !num_actions ) 2345 FT_TRACE5(( " (none)\n" )); 2346 FT_TRACE5(( "\n" )); 2347 #endif 2348 } 2349 2350 2351 /* Apply the complete hinting algorithm to a latin glyph. */ 2352 2353 static FT_Error 2354 af_latin_hints_apply( AF_GlyphHints hints, 2355 FT_Outline* outline, 2356 AF_LatinMetrics metrics ) 2357 { 2358 FT_Error error; 2359 int dim; 2360 2361 2362 error = af_glyph_hints_reload( hints, outline ); 2363 if ( error ) 2364 goto Exit; 2365 2366 /* analyze glyph outline */ 2367 #ifdef AF_CONFIG_OPTION_USE_WARPER 2368 if ( metrics->root.scaler.render_mode == FT_RENDER_MODE_LIGHT || 2369 AF_HINTS_DO_HORIZONTAL( hints ) ) 2370 #else 2371 if ( AF_HINTS_DO_HORIZONTAL( hints ) ) 2372 #endif 2373 { 2374 error = af_latin_hints_detect_features( hints, AF_DIMENSION_HORZ ); 2375 if ( error ) 2376 goto Exit; 2377 } 2378 2379 if ( AF_HINTS_DO_VERTICAL( hints ) ) 2380 { 2381 error = af_latin_hints_detect_features( hints, AF_DIMENSION_VERT ); 2382 if ( error ) 2383 goto Exit; 2384 2385 af_latin_hints_compute_blue_edges( hints, metrics ); 2386 } 2387 2388 /* grid-fit the outline */ 2389 for ( dim = 0; dim < AF_DIMENSION_MAX; dim++ ) 2390 { 2391 #ifdef AF_CONFIG_OPTION_USE_WARPER 2392 if ( dim == AF_DIMENSION_HORZ && 2393 metrics->root.scaler.render_mode == FT_RENDER_MODE_LIGHT ) 2394 { 2395 AF_WarperRec warper; 2396 FT_Fixed scale; 2397 FT_Pos delta; 2398 2399 2400 af_warper_compute( &warper, hints, (AF_Dimension)dim, 2401 &scale, &delta ); 2402 af_glyph_hints_scale_dim( hints, (AF_Dimension)dim, 2403 scale, delta ); 2404 continue; 2405 } 2406 #endif 2407 2408 if ( ( dim == AF_DIMENSION_HORZ && AF_HINTS_DO_HORIZONTAL( hints ) ) || 2409 ( dim == AF_DIMENSION_VERT && AF_HINTS_DO_VERTICAL( hints ) ) ) 2410 { 2411 af_latin_hint_edges( hints, (AF_Dimension)dim ); 2412 af_glyph_hints_align_edge_points( hints, (AF_Dimension)dim ); 2413 af_glyph_hints_align_strong_points( hints, (AF_Dimension)dim ); 2414 af_glyph_hints_align_weak_points( hints, (AF_Dimension)dim ); 2415 } 2416 } 2417 af_glyph_hints_save( hints, outline ); 2418 2419 Exit: 2420 return error; 2421 } 2422 2423 2424 /*************************************************************************/ 2425 /*************************************************************************/ 2426 /***** *****/ 2427 /***** L A T I N S C R I P T C L A S S *****/ 2428 /***** *****/ 2429 /*************************************************************************/ 2430 /*************************************************************************/ 2431 2432 2433 /* XXX: this should probably fine tuned to differentiate better between */ 2434 /* scripts... */ 2435 2436 static const AF_Script_UniRangeRec af_latin_uniranges[] = 2437 { 2438 AF_UNIRANGE_REC( 0x0020UL, 0x007FUL ), /* Basic Latin (no control chars) */ 2439 AF_UNIRANGE_REC( 0x00A0UL, 0x00FFUL ), /* Latin-1 Supplement (no control chars) */ 2440 AF_UNIRANGE_REC( 0x0100UL, 0x017FUL ), /* Latin Extended-A */ 2441 AF_UNIRANGE_REC( 0x0180UL, 0x024FUL ), /* Latin Extended-B */ 2442 AF_UNIRANGE_REC( 0x0250UL, 0x02AFUL ), /* IPA Extensions */ 2443 AF_UNIRANGE_REC( 0x02B0UL, 0x02FFUL ), /* Spacing Modifier Letters */ 2444 AF_UNIRANGE_REC( 0x0300UL, 0x036FUL ), /* Combining Diacritical Marks */ 2445 AF_UNIRANGE_REC( 0x0370UL, 0x03FFUL ), /* Greek and Coptic */ 2446 AF_UNIRANGE_REC( 0x0400UL, 0x04FFUL ), /* Cyrillic */ 2447 AF_UNIRANGE_REC( 0x0500UL, 0x052FUL ), /* Cyrillic Supplement */ 2448 AF_UNIRANGE_REC( 0x1D00UL, 0x1D7FUL ), /* Phonetic Extensions */ 2449 AF_UNIRANGE_REC( 0x1D80UL, 0x1DBFUL ), /* Phonetic Extensions Supplement */ 2450 AF_UNIRANGE_REC( 0x1DC0UL, 0x1DFFUL ), /* Combining Diacritical Marks Supplement */ 2451 AF_UNIRANGE_REC( 0x1E00UL, 0x1EFFUL ), /* Latin Extended Additional */ 2452 AF_UNIRANGE_REC( 0x1F00UL, 0x1FFFUL ), /* Greek Extended */ 2453 AF_UNIRANGE_REC( 0x2000UL, 0x206FUL ), /* General Punctuation */ 2454 AF_UNIRANGE_REC( 0x2070UL, 0x209FUL ), /* Superscripts and Subscripts */ 2455 AF_UNIRANGE_REC( 0x20A0UL, 0x20CFUL ), /* Currency Symbols */ 2456 AF_UNIRANGE_REC( 0x2150UL, 0x218FUL ), /* Number Forms */ 2457 AF_UNIRANGE_REC( 0x2460UL, 0x24FFUL ), /* Enclosed Alphanumerics */ 2458 AF_UNIRANGE_REC( 0x2C60UL, 0x2C7FUL ), /* Latin Extended-C */ 2459 AF_UNIRANGE_REC( 0x2DE0UL, 0x2DFFUL ), /* Cyrillic Extended-A */ 2460 AF_UNIRANGE_REC( 0x2E00UL, 0x2E7FUL ), /* Supplemental Punctuation */ 2461 AF_UNIRANGE_REC( 0xA640UL, 0xA69FUL ), /* Cyrillic Extended-B */ 2462 AF_UNIRANGE_REC( 0xA720UL, 0xA7FFUL ), /* Latin Extended-D */ 2463 AF_UNIRANGE_REC( 0xFB00UL, 0xFB06UL ), /* Alphab. Present. Forms (Latin Ligs) */ 2464 AF_UNIRANGE_REC( 0x1D400UL, 0x1D7FFUL ), /* Mathematical Alphanumeric Symbols */ 2465 AF_UNIRANGE_REC( 0x1F100UL, 0x1F1FFUL ), /* Enclosed Alphanumeric Supplement */ 2466 AF_UNIRANGE_REC( 0UL, 0UL ) 2467 }; 2468 2469 2470 AF_DEFINE_SCRIPT_CLASS( af_latin_script_class, 2471 AF_SCRIPT_LATIN, 2472 af_latin_uniranges, 2473 'o', 2474 2475 sizeof ( AF_LatinMetricsRec ), 2476 2477 (AF_Script_InitMetricsFunc) af_latin_metrics_init, 2478 (AF_Script_ScaleMetricsFunc)af_latin_metrics_scale, 2479 (AF_Script_DoneMetricsFunc) NULL, 2480 2481 (AF_Script_InitHintsFunc) af_latin_hints_init, 2482 (AF_Script_ApplyHintsFunc) af_latin_hints_apply 2483 ) 2484 2485 2486 /* END */ 2487
