1 /***************************************************************************/ 2 /* */ 3 /* aflatin.c */ 4 /* */ 5 /* Auto-fitter hinting routines for latin writing system (body). */ 6 /* */ 7 /* Copyright 2003-2018 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 ) 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 int dim; 83 AF_LatinMetricsRec dummy[1]; 84 AF_Scaler scaler = &dummy->root.scaler; 85 86 #ifdef FT_CONFIG_OPTION_PIC 87 AF_FaceGlobals globals = metrics->root.globals; 88 #endif 89 90 AF_StyleClass style_class = metrics->root.style_class; 91 AF_ScriptClass script_class = AF_SCRIPT_CLASSES_GET 92 [style_class->script]; 93 94 void* shaper_buf; 95 const char* p; 96 97 #ifdef FT_DEBUG_LEVEL_TRACE 98 FT_ULong ch = 0; 99 #endif 100 101 p = script_class->standard_charstring; 102 shaper_buf = af_shaper_buf_create( face ); 103 104 /* 105 * We check a list of standard characters to catch features like 106 * `c2sc' (small caps from caps) that don't contain lowercase letters 107 * by definition, or other features that mainly operate on numerals. 108 * The first match wins. 109 */ 110 111 glyph_index = 0; 112 while ( *p ) 113 { 114 unsigned int num_idx; 115 116 #ifdef FT_DEBUG_LEVEL_TRACE 117 const char* p_old; 118 #endif 119 120 121 while ( *p == ' ' ) 122 p++; 123 124 #ifdef FT_DEBUG_LEVEL_TRACE 125 p_old = p; 126 GET_UTF8_CHAR( ch, p_old ); 127 #endif 128 129 /* reject input that maps to more than a single glyph */ 130 p = af_shaper_get_cluster( p, &metrics->root, shaper_buf, &num_idx ); 131 if ( num_idx > 1 ) 132 continue; 133 134 /* otherwise exit loop if we have a result */ 135 glyph_index = af_shaper_get_elem( &metrics->root, 136 shaper_buf, 137 0, 138 NULL, 139 NULL ); 140 if ( glyph_index ) 141 break; 142 } 143 144 af_shaper_buf_destroy( face, shaper_buf ); 145 146 if ( !glyph_index ) 147 goto Exit; 148 149 FT_TRACE5(( "standard character: U+%04lX (glyph index %d)\n", 150 ch, glyph_index )); 151 152 error = FT_Load_Glyph( face, glyph_index, FT_LOAD_NO_SCALE ); 153 if ( error || face->glyph->outline.n_points <= 0 ) 154 goto Exit; 155 156 FT_ZERO( dummy ); 157 158 dummy->units_per_em = metrics->units_per_em; 159 160 scaler->x_scale = 0x10000L; 161 scaler->y_scale = 0x10000L; 162 scaler->x_delta = 0; 163 scaler->y_delta = 0; 164 165 scaler->face = face; 166 scaler->render_mode = FT_RENDER_MODE_NORMAL; 167 scaler->flags = 0; 168 169 af_glyph_hints_rescale( hints, (AF_StyleMetrics)dummy ); 170 171 error = af_glyph_hints_reload( hints, &face->glyph->outline ); 172 if ( error ) 173 goto Exit; 174 175 for ( dim = 0; dim < AF_DIMENSION_MAX; dim++ ) 176 { 177 AF_LatinAxis axis = &metrics->axis[dim]; 178 AF_AxisHints axhints = &hints->axis[dim]; 179 AF_Segment seg, limit, link; 180 FT_UInt num_widths = 0; 181 182 183 error = af_latin_hints_compute_segments( hints, 184 (AF_Dimension)dim ); 185 if ( error ) 186 goto Exit; 187 188 /* 189 * We assume that the glyphs selected for the stem width 190 * computation are `featureless' enough so that the linking 191 * algorithm works fine without adjustments of its scoring 192 * function. 193 */ 194 af_latin_hints_link_segments( hints, 195 0, 196 NULL, 197 (AF_Dimension)dim ); 198 199 seg = axhints->segments; 200 limit = seg + axhints->num_segments; 201 202 for ( ; seg < limit; seg++ ) 203 { 204 link = seg->link; 205 206 /* we only consider stem segments there! */ 207 if ( link && link->link == seg && link > seg ) 208 { 209 FT_Pos dist; 210 211 212 dist = seg->pos - link->pos; 213 if ( dist < 0 ) 214 dist = -dist; 215 216 if ( num_widths < AF_LATIN_MAX_WIDTHS ) 217 axis->widths[num_widths++].org = dist; 218 } 219 } 220 221 /* this also replaces multiple almost identical stem widths */ 222 /* with a single one (the value 100 is heuristic) */ 223 af_sort_and_quantize_widths( &num_widths, axis->widths, 224 dummy->units_per_em / 100 ); 225 axis->width_count = num_widths; 226 } 227 228 Exit: 229 for ( dim = 0; dim < AF_DIMENSION_MAX; dim++ ) 230 { 231 AF_LatinAxis axis = &metrics->axis[dim]; 232 FT_Pos stdw; 233 234 235 stdw = ( axis->width_count > 0 ) ? axis->widths[0].org 236 : AF_LATIN_CONSTANT( metrics, 50 ); 237 238 /* let's try 20% of the smallest width */ 239 axis->edge_distance_threshold = stdw / 5; 240 axis->standard_width = stdw; 241 axis->extra_light = 0; 242 243 #ifdef FT_DEBUG_LEVEL_TRACE 244 { 245 FT_UInt i; 246 247 248 FT_TRACE5(( "%s widths:\n", 249 dim == AF_DIMENSION_VERT ? "horizontal" 250 : "vertical" )); 251 252 FT_TRACE5(( " %d (standard)", axis->standard_width )); 253 for ( i = 1; i < axis->width_count; i++ ) 254 FT_TRACE5(( " %d", axis->widths[i].org )); 255 256 FT_TRACE5(( "\n" )); 257 } 258 #endif 259 } 260 } 261 262 FT_TRACE5(( "\n" )); 263 264 af_glyph_hints_done( hints ); 265 } 266 267 268 static void 269 af_latin_sort_blue( FT_UInt count, 270 AF_LatinBlue* table ) 271 { 272 FT_UInt i, j; 273 AF_LatinBlue swap; 274 275 276 /* we sort from bottom to top */ 277 for ( i = 1; i < count; i++ ) 278 { 279 for ( j = i; j > 0; j-- ) 280 { 281 FT_Pos a, b; 282 283 284 if ( table[j - 1]->flags & ( AF_LATIN_BLUE_TOP | 285 AF_LATIN_BLUE_SUB_TOP ) ) 286 a = table[j - 1]->ref.org; 287 else 288 a = table[j - 1]->shoot.org; 289 290 if ( table[j]->flags & ( AF_LATIN_BLUE_TOP | 291 AF_LATIN_BLUE_SUB_TOP ) ) 292 b = table[j]->ref.org; 293 else 294 b = table[j]->shoot.org; 295 296 if ( b >= a ) 297 break; 298 299 swap = table[j]; 300 table[j] = table[j - 1]; 301 table[j - 1] = swap; 302 } 303 } 304 } 305 306 307 /* Find all blue zones. Flat segments give the reference points, */ 308 /* round segments the overshoot positions. */ 309 310 static void 311 af_latin_metrics_init_blues( AF_LatinMetrics metrics, 312 FT_Face face ) 313 { 314 FT_Pos flats [AF_BLUE_STRING_MAX_LEN]; 315 FT_Pos rounds[AF_BLUE_STRING_MAX_LEN]; 316 317 FT_UInt num_flats; 318 FT_UInt num_rounds; 319 320 AF_LatinBlue blue; 321 FT_Error error; 322 AF_LatinAxis axis = &metrics->axis[AF_DIMENSION_VERT]; 323 FT_Outline outline; 324 325 AF_StyleClass sc = metrics->root.style_class; 326 327 AF_Blue_Stringset bss = sc->blue_stringset; 328 const AF_Blue_StringRec* bs = &af_blue_stringsets[bss]; 329 330 FT_Pos flat_threshold = FLAT_THRESHOLD( metrics->units_per_em ); 331 332 void* shaper_buf; 333 334 335 /* we walk over the blue character strings as specified in the */ 336 /* style's entry in the `af_blue_stringset' array */ 337 338 FT_TRACE5(( "latin blue zones computation\n" 339 "============================\n" 340 "\n" )); 341 342 shaper_buf = af_shaper_buf_create( face ); 343 344 for ( ; bs->string != AF_BLUE_STRING_MAX; bs++ ) 345 { 346 const char* p = &af_blue_strings[bs->string]; 347 FT_Pos* blue_ref; 348 FT_Pos* blue_shoot; 349 FT_Pos ascender; 350 FT_Pos descender; 351 352 353 #ifdef FT_DEBUG_LEVEL_TRACE 354 { 355 FT_Bool have_flag = 0; 356 357 358 FT_TRACE5(( "blue zone %d", axis->blue_count )); 359 360 if ( bs->properties ) 361 { 362 FT_TRACE5(( " (" )); 363 364 if ( AF_LATIN_IS_TOP_BLUE( bs ) ) 365 { 366 FT_TRACE5(( "top" )); 367 have_flag = 1; 368 } 369 else if ( AF_LATIN_IS_SUB_TOP_BLUE( bs ) ) 370 { 371 FT_TRACE5(( "sub top" )); 372 have_flag = 1; 373 } 374 375 if ( AF_LATIN_IS_NEUTRAL_BLUE( bs ) ) 376 { 377 if ( have_flag ) 378 FT_TRACE5(( ", " )); 379 FT_TRACE5(( "neutral" )); 380 have_flag = 1; 381 } 382 383 if ( AF_LATIN_IS_X_HEIGHT_BLUE( bs ) ) 384 { 385 if ( have_flag ) 386 FT_TRACE5(( ", " )); 387 FT_TRACE5(( "small top" )); 388 have_flag = 1; 389 } 390 391 if ( AF_LATIN_IS_LONG_BLUE( bs ) ) 392 { 393 if ( have_flag ) 394 FT_TRACE5(( ", " )); 395 FT_TRACE5(( "long" )); 396 } 397 398 FT_TRACE5(( ")" )); 399 } 400 401 FT_TRACE5(( ":\n" )); 402 } 403 #endif /* FT_DEBUG_LEVEL_TRACE */ 404 405 num_flats = 0; 406 num_rounds = 0; 407 ascender = 0; 408 descender = 0; 409 410 while ( *p ) 411 { 412 FT_ULong glyph_index; 413 FT_Long y_offset; 414 FT_Int best_point, best_contour_first, best_contour_last; 415 FT_Vector* points; 416 417 FT_Pos best_y_extremum; /* same as points.y */ 418 FT_Bool best_round = 0; 419 420 unsigned int i, num_idx; 421 422 #ifdef FT_DEBUG_LEVEL_TRACE 423 const char* p_old; 424 FT_ULong ch; 425 #endif 426 427 428 while ( *p == ' ' ) 429 p++; 430 431 #ifdef FT_DEBUG_LEVEL_TRACE 432 p_old = p; 433 GET_UTF8_CHAR( ch, p_old ); 434 #endif 435 436 p = af_shaper_get_cluster( p, &metrics->root, shaper_buf, &num_idx ); 437 438 if ( !num_idx ) 439 { 440 FT_TRACE5(( " U+%04lX unavailable\n", ch )); 441 continue; 442 } 443 444 if ( AF_LATIN_IS_TOP_BLUE( bs ) ) 445 best_y_extremum = FT_INT_MIN; 446 else 447 best_y_extremum = FT_INT_MAX; 448 449 /* iterate over all glyph elements of the character cluster */ 450 /* and get the data of the `biggest' one */ 451 for ( i = 0; i < num_idx; i++ ) 452 { 453 FT_Pos best_y; 454 FT_Bool round = 0; 455 456 457 /* load the character in the face -- skip unknown or empty ones */ 458 glyph_index = af_shaper_get_elem( &metrics->root, 459 shaper_buf, 460 i, 461 NULL, 462 &y_offset ); 463 if ( glyph_index == 0 ) 464 { 465 FT_TRACE5(( " U+%04lX unavailable\n", ch )); 466 continue; 467 } 468 469 error = FT_Load_Glyph( face, glyph_index, FT_LOAD_NO_SCALE ); 470 outline = face->glyph->outline; 471 /* reject glyphs that don't produce any rendering */ 472 if ( error || outline.n_points <= 2 ) 473 { 474 #ifdef FT_DEBUG_LEVEL_TRACE 475 if ( num_idx == 1 ) 476 FT_TRACE5(( " U+%04lX contains no (usable) outlines\n", ch )); 477 else 478 FT_TRACE5(( " component %d of cluster starting with U+%04lX" 479 " contains no (usable) outlines\n", i, ch )); 480 #endif 481 continue; 482 } 483 484 /* now compute min or max point indices and coordinates */ 485 points = outline.points; 486 best_point = -1; 487 best_y = 0; /* make compiler happy */ 488 best_contour_first = 0; /* ditto */ 489 best_contour_last = 0; /* ditto */ 490 491 { 492 FT_Int nn; 493 FT_Int first = 0; 494 FT_Int last = -1; 495 496 497 for ( nn = 0; nn < outline.n_contours; first = last + 1, nn++ ) 498 { 499 FT_Int old_best_point = best_point; 500 FT_Int pp; 501 502 503 last = outline.contours[nn]; 504 505 /* Avoid single-point contours since they are never */ 506 /* rasterized. In some fonts, they correspond to mark */ 507 /* attachment points that are way outside of the glyph's */ 508 /* real outline. */ 509 if ( last <= first ) 510 continue; 511 512 if ( AF_LATIN_IS_TOP_BLUE( bs ) || 513 AF_LATIN_IS_SUB_TOP_BLUE( bs ) ) 514 { 515 for ( pp = first; pp <= last; pp++ ) 516 { 517 if ( best_point < 0 || points[pp].y > best_y ) 518 { 519 best_point = pp; 520 best_y = points[pp].y; 521 ascender = FT_MAX( ascender, best_y + y_offset ); 522 } 523 else 524 descender = FT_MIN( descender, points[pp].y + y_offset ); 525 } 526 } 527 else 528 { 529 for ( pp = first; pp <= last; pp++ ) 530 { 531 if ( best_point < 0 || points[pp].y < best_y ) 532 { 533 best_point = pp; 534 best_y = points[pp].y; 535 descender = FT_MIN( descender, best_y + y_offset ); 536 } 537 else 538 ascender = FT_MAX( ascender, points[pp].y + y_offset ); 539 } 540 } 541 542 if ( best_point != old_best_point ) 543 { 544 best_contour_first = first; 545 best_contour_last = last; 546 } 547 } 548 } 549 550 /* now check whether the point belongs to a straight or round */ 551 /* segment; we first need to find in which contour the extremum */ 552 /* lies, then inspect its previous and next points */ 553 if ( best_point >= 0 ) 554 { 555 FT_Pos best_x = points[best_point].x; 556 FT_Int prev, next; 557 FT_Int best_segment_first, best_segment_last; 558 FT_Int best_on_point_first, best_on_point_last; 559 FT_Pos dist; 560 561 562 best_segment_first = best_point; 563 best_segment_last = best_point; 564 565 if ( FT_CURVE_TAG( outline.tags[best_point] ) == FT_CURVE_TAG_ON ) 566 { 567 best_on_point_first = best_point; 568 best_on_point_last = best_point; 569 } 570 else 571 { 572 best_on_point_first = -1; 573 best_on_point_last = -1; 574 } 575 576 /* look for the previous and next points on the contour */ 577 /* that are not on the same Y coordinate, then threshold */ 578 /* the `closeness'... */ 579 prev = best_point; 580 next = prev; 581 582 do 583 { 584 if ( prev > best_contour_first ) 585 prev--; 586 else 587 prev = best_contour_last; 588 589 dist = FT_ABS( points[prev].y - best_y ); 590 /* accept a small distance or a small angle (both values are */ 591 /* heuristic; value 20 corresponds to approx. 2.9 degrees) */ 592 if ( dist > 5 ) 593 if ( FT_ABS( points[prev].x - best_x ) <= 20 * dist ) 594 break; 595 596 best_segment_first = prev; 597 598 if ( FT_CURVE_TAG( outline.tags[prev] ) == FT_CURVE_TAG_ON ) 599 { 600 best_on_point_first = prev; 601 if ( best_on_point_last < 0 ) 602 best_on_point_last = prev; 603 } 604 605 } while ( prev != best_point ); 606 607 do 608 { 609 if ( next < best_contour_last ) 610 next++; 611 else 612 next = best_contour_first; 613 614 dist = FT_ABS( points[next].y - best_y ); 615 if ( dist > 5 ) 616 if ( FT_ABS( points[next].x - best_x ) <= 20 * dist ) 617 break; 618 619 best_segment_last = next; 620 621 if ( FT_CURVE_TAG( outline.tags[next] ) == FT_CURVE_TAG_ON ) 622 { 623 best_on_point_last = next; 624 if ( best_on_point_first < 0 ) 625 best_on_point_first = next; 626 } 627 628 } while ( next != best_point ); 629 630 if ( AF_LATIN_IS_LONG_BLUE( bs ) ) 631 { 632 /* If this flag is set, we have an additional constraint to */ 633 /* get the blue zone distance: Find a segment of the topmost */ 634 /* (or bottommost) contour that is longer than a heuristic */ 635 /* threshold. This ensures that small bumps in the outline */ 636 /* are ignored (for example, the `vertical serifs' found in */ 637 /* many Hebrew glyph designs). */ 638 639 /* If this segment is long enough, we are done. Otherwise, */ 640 /* search the segment next to the extremum that is long */ 641 /* enough, has the same direction, and a not too large */ 642 /* vertical distance from the extremum. Note that the */ 643 /* algorithm doesn't check whether the found segment is */ 644 /* actually the one (vertically) nearest to the extremum. */ 645 646 /* heuristic threshold value */ 647 FT_Pos length_threshold = metrics->units_per_em / 25; 648 649 650 dist = FT_ABS( points[best_segment_last].x - 651 points[best_segment_first].x ); 652 653 if ( dist < length_threshold && 654 best_segment_last - best_segment_first + 2 <= 655 best_contour_last - best_contour_first ) 656 { 657 /* heuristic threshold value */ 658 FT_Pos height_threshold = metrics->units_per_em / 4; 659 660 FT_Int first; 661 FT_Int last; 662 FT_Bool hit; 663 664 /* we intentionally declare these two variables */ 665 /* outside of the loop since various compilers emit */ 666 /* incorrect warning messages otherwise, talking about */ 667 /* `possibly uninitialized variables' */ 668 FT_Int p_first = 0; /* make compiler happy */ 669 FT_Int p_last = 0; 670 671 FT_Bool left2right; 672 673 674 /* compute direction */ 675 prev = best_point; 676 677 do 678 { 679 if ( prev > best_contour_first ) 680 prev--; 681 else 682 prev = best_contour_last; 683 684 if ( points[prev].x != best_x ) 685 break; 686 687 } while ( prev != best_point ); 688 689 /* skip glyph for the degenerate case */ 690 if ( prev == best_point ) 691 continue; 692 693 left2right = FT_BOOL( points[prev].x < points[best_point].x ); 694 695 first = best_segment_last; 696 last = first; 697 hit = 0; 698 699 do 700 { 701 FT_Bool l2r; 702 FT_Pos d; 703 704 705 if ( !hit ) 706 { 707 /* no hit; adjust first point */ 708 first = last; 709 710 /* also adjust first and last on point */ 711 if ( FT_CURVE_TAG( outline.tags[first] ) == 712 FT_CURVE_TAG_ON ) 713 { 714 p_first = first; 715 p_last = first; 716 } 717 else 718 { 719 p_first = -1; 720 p_last = -1; 721 } 722 723 hit = 1; 724 } 725 726 if ( last < best_contour_last ) 727 last++; 728 else 729 last = best_contour_first; 730 731 if ( FT_ABS( best_y - points[first].y ) > height_threshold ) 732 { 733 /* vertical distance too large */ 734 hit = 0; 735 continue; 736 } 737 738 /* same test as above */ 739 dist = FT_ABS( points[last].y - points[first].y ); 740 if ( dist > 5 ) 741 if ( FT_ABS( points[last].x - points[first].x ) <= 742 20 * dist ) 743 { 744 hit = 0; 745 continue; 746 } 747 748 if ( FT_CURVE_TAG( outline.tags[last] ) == FT_CURVE_TAG_ON ) 749 { 750 p_last = last; 751 if ( p_first < 0 ) 752 p_first = last; 753 } 754 755 l2r = FT_BOOL( points[first].x < points[last].x ); 756 d = FT_ABS( points[last].x - points[first].x ); 757 758 if ( l2r == left2right && 759 d >= length_threshold ) 760 { 761 /* all constraints are met; update segment after */ 762 /* finding its end */ 763 do 764 { 765 if ( last < best_contour_last ) 766 last++; 767 else 768 last = best_contour_first; 769 770 d = FT_ABS( points[last].y - points[first].y ); 771 if ( d > 5 ) 772 if ( FT_ABS( points[next].x - points[first].x ) <= 773 20 * dist ) 774 { 775 if ( last > best_contour_first ) 776 last--; 777 else 778 last = best_contour_last; 779 break; 780 } 781 782 p_last = last; 783 784 if ( FT_CURVE_TAG( outline.tags[last] ) == 785 FT_CURVE_TAG_ON ) 786 { 787 p_last = last; 788 if ( p_first < 0 ) 789 p_first = last; 790 } 791 792 } while ( last != best_segment_first ); 793 794 best_y = points[first].y; 795 796 best_segment_first = first; 797 best_segment_last = last; 798 799 best_on_point_first = p_first; 800 best_on_point_last = p_last; 801 802 break; 803 } 804 805 } while ( last != best_segment_first ); 806 } 807 } 808 809 /* for computing blue zones, we add the y offset as returned */ 810 /* by the currently used OpenType feature -- for example, */ 811 /* superscript glyphs might be identical to subscript glyphs */ 812 /* with a vertical shift */ 813 best_y += y_offset; 814 815 #ifdef FT_DEBUG_LEVEL_TRACE 816 if ( num_idx == 1 ) 817 FT_TRACE5(( " U+%04lX: best_y = %5ld", ch, best_y )); 818 else 819 FT_TRACE5(( " component %d of cluster starting with U+%04lX:" 820 " best_y = %5ld", i, ch, best_y )); 821 #endif 822 823 /* now set the `round' flag depending on the segment's kind: */ 824 /* */ 825 /* - if the horizontal distance between the first and last */ 826 /* `on' point is larger than a heuristic threshold */ 827 /* we have a flat segment */ 828 /* - if either the first or the last point of the segment is */ 829 /* an `off' point, the segment is round, otherwise it is */ 830 /* flat */ 831 if ( best_on_point_first >= 0 && 832 best_on_point_last >= 0 && 833 ( FT_ABS( points[best_on_point_last].x - 834 points[best_on_point_first].x ) ) > 835 flat_threshold ) 836 round = 0; 837 else 838 round = FT_BOOL( 839 FT_CURVE_TAG( outline.tags[best_segment_first] ) != 840 FT_CURVE_TAG_ON || 841 FT_CURVE_TAG( outline.tags[best_segment_last] ) != 842 FT_CURVE_TAG_ON ); 843 844 if ( round && AF_LATIN_IS_NEUTRAL_BLUE( bs ) ) 845 { 846 /* only use flat segments for a neutral blue zone */ 847 FT_TRACE5(( " (round, skipped)\n" )); 848 continue; 849 } 850 851 FT_TRACE5(( " (%s)\n", round ? "round" : "flat" )); 852 } 853 854 if ( AF_LATIN_IS_TOP_BLUE( bs ) ) 855 { 856 if ( best_y > best_y_extremum ) 857 { 858 best_y_extremum = best_y; 859 best_round = round; 860 } 861 } 862 else 863 { 864 if ( best_y < best_y_extremum ) 865 { 866 best_y_extremum = best_y; 867 best_round = round; 868 } 869 } 870 871 } /* end for loop */ 872 873 if ( !( best_y_extremum == FT_INT_MIN || 874 best_y_extremum == FT_INT_MAX ) ) 875 { 876 if ( best_round ) 877 rounds[num_rounds++] = best_y_extremum; 878 else 879 flats[num_flats++] = best_y_extremum; 880 } 881 882 } /* end while loop */ 883 884 if ( num_flats == 0 && num_rounds == 0 ) 885 { 886 /* 887 * we couldn't find a single glyph to compute this blue zone, 888 * we will simply ignore it then 889 */ 890 FT_TRACE5(( " empty\n" )); 891 continue; 892 } 893 894 /* we have computed the contents of the `rounds' and `flats' tables, */ 895 /* now determine the reference and overshoot position of the blue -- */ 896 /* we simply take the median value after a simple sort */ 897 af_sort_pos( num_rounds, rounds ); 898 af_sort_pos( num_flats, flats ); 899 900 blue = &axis->blues[axis->blue_count]; 901 blue_ref = &blue->ref.org; 902 blue_shoot = &blue->shoot.org; 903 904 axis->blue_count++; 905 906 if ( num_flats == 0 ) 907 { 908 *blue_ref = 909 *blue_shoot = rounds[num_rounds / 2]; 910 } 911 else if ( num_rounds == 0 ) 912 { 913 *blue_ref = 914 *blue_shoot = flats[num_flats / 2]; 915 } 916 else 917 { 918 *blue_ref = flats [num_flats / 2]; 919 *blue_shoot = rounds[num_rounds / 2]; 920 } 921 922 /* there are sometimes problems: if the overshoot position of top */ 923 /* zones is under its reference position, or the opposite for bottom */ 924 /* zones. We must thus check everything there and correct the errors */ 925 if ( *blue_shoot != *blue_ref ) 926 { 927 FT_Pos ref = *blue_ref; 928 FT_Pos shoot = *blue_shoot; 929 FT_Bool over_ref = FT_BOOL( shoot > ref ); 930 931 932 if ( ( AF_LATIN_IS_TOP_BLUE( bs ) || 933 AF_LATIN_IS_SUB_TOP_BLUE( bs) ) ^ over_ref ) 934 { 935 *blue_ref = 936 *blue_shoot = ( shoot + ref ) / 2; 937 938 FT_TRACE5(( " [overshoot smaller than reference," 939 " taking mean value]\n" )); 940 } 941 } 942 943 blue->ascender = ascender; 944 blue->descender = descender; 945 946 blue->flags = 0; 947 if ( AF_LATIN_IS_TOP_BLUE( bs ) ) 948 blue->flags |= AF_LATIN_BLUE_TOP; 949 if ( AF_LATIN_IS_SUB_TOP_BLUE( bs ) ) 950 blue->flags |= AF_LATIN_BLUE_SUB_TOP; 951 if ( AF_LATIN_IS_NEUTRAL_BLUE( bs ) ) 952 blue->flags |= AF_LATIN_BLUE_NEUTRAL; 953 954 /* 955 * The following flag is used later to adjust the y and x scales 956 * in order to optimize the pixel grid alignment of the top of small 957 * letters. 958 */ 959 if ( AF_LATIN_IS_X_HEIGHT_BLUE( bs ) ) 960 blue->flags |= AF_LATIN_BLUE_ADJUSTMENT; 961 962 FT_TRACE5(( " -> reference = %ld\n" 963 " overshoot = %ld\n", 964 *blue_ref, *blue_shoot )); 965 966 } /* end for loop */ 967 968 af_shaper_buf_destroy( face, shaper_buf ); 969 970 /* we finally check whether blue zones are ordered; */ 971 /* `ref' and `shoot' values of two blue zones must not overlap */ 972 if ( axis->blue_count ) 973 { 974 FT_UInt i; 975 AF_LatinBlue blue_sorted[AF_BLUE_STRINGSET_MAX_LEN + 2]; 976 977 978 for ( i = 0; i < axis->blue_count; i++ ) 979 blue_sorted[i] = &axis->blues[i]; 980 981 /* sort bottoms of blue zones... */ 982 af_latin_sort_blue( axis->blue_count, blue_sorted ); 983 984 /* ...and adjust top values if necessary */ 985 for ( i = 0; i < axis->blue_count - 1; i++ ) 986 { 987 FT_Pos* a; 988 FT_Pos* b; 989 990 #ifdef FT_DEBUG_LEVEL_TRACE 991 FT_Bool a_is_top = 0; 992 #endif 993 994 995 if ( blue_sorted[i]->flags & ( AF_LATIN_BLUE_TOP | 996 AF_LATIN_BLUE_SUB_TOP ) ) 997 { 998 a = &blue_sorted[i]->shoot.org; 999 #ifdef FT_DEBUG_LEVEL_TRACE 1000 a_is_top = 1; 1001 #endif 1002 } 1003 else 1004 a = &blue_sorted[i]->ref.org; 1005 1006 if ( blue_sorted[i + 1]->flags & ( AF_LATIN_BLUE_TOP | 1007 AF_LATIN_BLUE_SUB_TOP ) ) 1008 b = &blue_sorted[i + 1]->shoot.org; 1009 else 1010 b = &blue_sorted[i + 1]->ref.org; 1011 1012 if ( *a > *b ) 1013 { 1014 *a = *b; 1015 FT_TRACE5(( "blue zone overlap:" 1016 " adjusting %s %d to %ld\n", 1017 a_is_top ? "overshoot" : "reference", 1018 blue_sorted[i] - axis->blues, 1019 *a )); 1020 } 1021 } 1022 } 1023 1024 FT_TRACE5(( "\n" )); 1025 1026 return; 1027 } 1028 1029 1030 /* Check whether all ASCII digits have the same advance width. */ 1031 1032 FT_LOCAL_DEF( void ) 1033 af_latin_metrics_check_digits( AF_LatinMetrics metrics, 1034 FT_Face face ) 1035 { 1036 FT_Bool started = 0, same_width = 1; 1037 FT_Fixed advance = 0, old_advance = 0; 1038 1039 void* shaper_buf; 1040 1041 /* in all supported charmaps, digits have character codes 0x30-0x39 */ 1042 const char digits[] = "0 1 2 3 4 5 6 7 8 9"; 1043 const char* p; 1044 1045 1046 p = digits; 1047 shaper_buf = af_shaper_buf_create( face ); 1048 1049 while ( *p ) 1050 { 1051 FT_ULong glyph_index; 1052 unsigned int num_idx; 1053 1054 1055 /* reject input that maps to more than a single glyph */ 1056 p = af_shaper_get_cluster( p, &metrics->root, shaper_buf, &num_idx ); 1057 if ( num_idx > 1 ) 1058 continue; 1059 1060 glyph_index = af_shaper_get_elem( &metrics->root, 1061 shaper_buf, 1062 0, 1063 &advance, 1064 NULL ); 1065 if ( !glyph_index ) 1066 continue; 1067 1068 if ( started ) 1069 { 1070 if ( advance != old_advance ) 1071 { 1072 same_width = 0; 1073 break; 1074 } 1075 } 1076 else 1077 { 1078 old_advance = advance; 1079 started = 1; 1080 } 1081 } 1082 1083 af_shaper_buf_destroy( face, shaper_buf ); 1084 1085 metrics->root.digits_have_same_width = same_width; 1086 } 1087 1088 1089 /* Initialize global metrics. */ 1090 1091 FT_LOCAL_DEF( FT_Error ) 1092 af_latin_metrics_init( AF_LatinMetrics metrics, 1093 FT_Face face ) 1094 { 1095 FT_CharMap oldmap = face->charmap; 1096 1097 1098 metrics->units_per_em = face->units_per_EM; 1099 1100 if ( !FT_Select_Charmap( face, FT_ENCODING_UNICODE ) ) 1101 { 1102 af_latin_metrics_init_widths( metrics, face ); 1103 af_latin_metrics_init_blues( metrics, face ); 1104 af_latin_metrics_check_digits( metrics, face ); 1105 } 1106 1107 FT_Set_Charmap( face, oldmap ); 1108 return FT_Err_Ok; 1109 } 1110 1111 1112 /* Adjust scaling value, then scale and shift widths */ 1113 /* and blue zones (if applicable) for given dimension. */ 1114 1115 static void 1116 af_latin_metrics_scale_dim( AF_LatinMetrics metrics, 1117 AF_Scaler scaler, 1118 AF_Dimension dim ) 1119 { 1120 FT_Fixed scale; 1121 FT_Pos delta; 1122 AF_LatinAxis axis; 1123 FT_UInt nn; 1124 1125 1126 if ( dim == AF_DIMENSION_HORZ ) 1127 { 1128 scale = scaler->x_scale; 1129 delta = scaler->x_delta; 1130 } 1131 else 1132 { 1133 scale = scaler->y_scale; 1134 delta = scaler->y_delta; 1135 } 1136 1137 axis = &metrics->axis[dim]; 1138 1139 if ( axis->org_scale == scale && axis->org_delta == delta ) 1140 return; 1141 1142 axis->org_scale = scale; 1143 axis->org_delta = delta; 1144 1145 /* 1146 * correct X and Y scale to optimize the alignment of the top of small 1147 * letters to the pixel grid 1148 */ 1149 { 1150 AF_LatinAxis Axis = &metrics->axis[AF_DIMENSION_VERT]; 1151 AF_LatinBlue blue = NULL; 1152 1153 1154 for ( nn = 0; nn < Axis->blue_count; nn++ ) 1155 { 1156 if ( Axis->blues[nn].flags & AF_LATIN_BLUE_ADJUSTMENT ) 1157 { 1158 blue = &Axis->blues[nn]; 1159 break; 1160 } 1161 } 1162 1163 if ( blue ) 1164 { 1165 FT_Pos scaled; 1166 FT_Pos threshold; 1167 FT_Pos fitted; 1168 FT_UInt limit; 1169 FT_UInt ppem; 1170 1171 1172 scaled = FT_MulFix( blue->shoot.org, scale ); 1173 ppem = metrics->root.scaler.face->size->metrics.x_ppem; 1174 limit = metrics->root.globals->increase_x_height; 1175 threshold = 40; 1176 1177 /* if the `increase-x-height' property is active, */ 1178 /* we round up much more often */ 1179 if ( limit && 1180 ppem <= limit && 1181 ppem >= AF_PROP_INCREASE_X_HEIGHT_MIN ) 1182 threshold = 52; 1183 1184 fitted = ( scaled + threshold ) & ~63; 1185 1186 if ( scaled != fitted ) 1187 { 1188 #if 0 1189 if ( dim == AF_DIMENSION_HORZ ) 1190 { 1191 if ( fitted < scaled ) 1192 scale -= scale / 50; /* scale *= 0.98 */ 1193 } 1194 else 1195 #endif 1196 if ( dim == AF_DIMENSION_VERT ) 1197 { 1198 FT_Pos max_height; 1199 FT_Pos dist; 1200 FT_Fixed new_scale; 1201 1202 1203 new_scale = FT_MulDiv( scale, fitted, scaled ); 1204 1205 /* the scaling should not change the result by more than two pixels */ 1206 max_height = metrics->units_per_em; 1207 1208 for ( nn = 0; nn < Axis->blue_count; nn++ ) 1209 { 1210 max_height = FT_MAX( max_height, Axis->blues[nn].ascender ); 1211 max_height = FT_MAX( max_height, -Axis->blues[nn].descender ); 1212 } 1213 1214 dist = FT_ABS( FT_MulFix( max_height, new_scale - scale ) ); 1215 dist &= ~127; 1216 1217 if ( dist == 0 ) 1218 { 1219 FT_TRACE5(( 1220 "af_latin_metrics_scale_dim:" 1221 " x height alignment (style `%s'):\n" 1222 " " 1223 " vertical scaling changed from %.5f to %.5f (by %d%%)\n" 1224 "\n", 1225 af_style_names[metrics->root.style_class->style], 1226 scale / 65536.0, 1227 new_scale / 65536.0, 1228 ( fitted - scaled ) * 100 / scaled )); 1229 1230 scale = new_scale; 1231 } 1232 #ifdef FT_DEBUG_LEVEL_TRACE 1233 else 1234 { 1235 FT_TRACE5(( 1236 "af_latin_metrics_scale_dim:" 1237 " x height alignment (style `%s'):\n" 1238 " " 1239 " excessive vertical scaling abandoned\n" 1240 "\n", 1241 af_style_names[metrics->root.style_class->style] )); 1242 } 1243 #endif 1244 } 1245 } 1246 } 1247 } 1248 1249 axis->scale = scale; 1250 axis->delta = delta; 1251 1252 if ( dim == AF_DIMENSION_HORZ ) 1253 { 1254 metrics->root.scaler.x_scale = scale; 1255 metrics->root.scaler.x_delta = delta; 1256 } 1257 else 1258 { 1259 metrics->root.scaler.y_scale = scale; 1260 metrics->root.scaler.y_delta = delta; 1261 } 1262 1263 FT_TRACE5(( "%s widths (style `%s')\n", 1264 dim == AF_DIMENSION_HORZ ? "horizontal" : "vertical", 1265 af_style_names[metrics->root.style_class->style] )); 1266 1267 /* scale the widths */ 1268 for ( nn = 0; nn < axis->width_count; nn++ ) 1269 { 1270 AF_Width width = axis->widths + nn; 1271 1272 1273 width->cur = FT_MulFix( width->org, scale ); 1274 width->fit = width->cur; 1275 1276 FT_TRACE5(( " %d scaled to %.2f\n", 1277 width->org, 1278 width->cur / 64.0 )); 1279 } 1280 1281 FT_TRACE5(( "\n" )); 1282 1283 /* an extra-light axis corresponds to a standard width that is */ 1284 /* smaller than 5/8 pixels */ 1285 axis->extra_light = 1286 (FT_Bool)( FT_MulFix( axis->standard_width, scale ) < 32 + 8 ); 1287 1288 #ifdef FT_DEBUG_LEVEL_TRACE 1289 if ( axis->extra_light ) 1290 FT_TRACE5(( "`%s' style is extra light (at current resolution)\n" 1291 "\n", 1292 af_style_names[metrics->root.style_class->style] )); 1293 #endif 1294 1295 if ( dim == AF_DIMENSION_VERT ) 1296 { 1297 #ifdef FT_DEBUG_LEVEL_TRACE 1298 if ( axis->blue_count ) 1299 FT_TRACE5(( "blue zones (style `%s')\n", 1300 af_style_names[metrics->root.style_class->style] )); 1301 #endif 1302 1303 /* scale the blue zones */ 1304 for ( nn = 0; nn < axis->blue_count; nn++ ) 1305 { 1306 AF_LatinBlue blue = &axis->blues[nn]; 1307 FT_Pos dist; 1308 1309 1310 blue->ref.cur = FT_MulFix( blue->ref.org, scale ) + delta; 1311 blue->ref.fit = blue->ref.cur; 1312 blue->shoot.cur = FT_MulFix( blue->shoot.org, scale ) + delta; 1313 blue->shoot.fit = blue->shoot.cur; 1314 blue->flags &= ~AF_LATIN_BLUE_ACTIVE; 1315 1316 /* a blue zone is only active if it is less than 3/4 pixels tall */ 1317 dist = FT_MulFix( blue->ref.org - blue->shoot.org, scale ); 1318 if ( dist <= 48 && dist >= -48 ) 1319 { 1320 #if 0 1321 FT_Pos delta1; 1322 #endif 1323 FT_Pos delta2; 1324 1325 1326 /* use discrete values for blue zone widths */ 1327 1328 #if 0 1329 1330 /* generic, original code */ 1331 delta1 = blue->shoot.org - blue->ref.org; 1332 delta2 = delta1; 1333 if ( delta1 < 0 ) 1334 delta2 = -delta2; 1335 1336 delta2 = FT_MulFix( delta2, scale ); 1337 1338 if ( delta2 < 32 ) 1339 delta2 = 0; 1340 else if ( delta2 < 64 ) 1341 delta2 = 32 + ( ( ( delta2 - 32 ) + 16 ) & ~31 ); 1342 else 1343 delta2 = FT_PIX_ROUND( delta2 ); 1344 1345 if ( delta1 < 0 ) 1346 delta2 = -delta2; 1347 1348 blue->ref.fit = FT_PIX_ROUND( blue->ref.cur ); 1349 blue->shoot.fit = blue->ref.fit + delta2; 1350 1351 #else 1352 1353 /* simplified version due to abs(dist) <= 48 */ 1354 delta2 = dist; 1355 if ( dist < 0 ) 1356 delta2 = -delta2; 1357 1358 if ( delta2 < 32 ) 1359 delta2 = 0; 1360 else if ( delta2 < 48 ) 1361 delta2 = 32; 1362 else 1363 delta2 = 64; 1364 1365 if ( dist < 0 ) 1366 delta2 = -delta2; 1367 1368 blue->ref.fit = FT_PIX_ROUND( blue->ref.cur ); 1369 blue->shoot.fit = blue->ref.fit - delta2; 1370 1371 #endif 1372 1373 blue->flags |= AF_LATIN_BLUE_ACTIVE; 1374 } 1375 } 1376 1377 /* use sub-top blue zone only if it doesn't overlap with */ 1378 /* another (non-sup-top) blue zone; otherwise, the */ 1379 /* effect would be similar to a neutral blue zone, which */ 1380 /* is not desired here */ 1381 for ( nn = 0; nn < axis->blue_count; nn++ ) 1382 { 1383 AF_LatinBlue blue = &axis->blues[nn]; 1384 FT_UInt i; 1385 1386 1387 if ( !( blue->flags & AF_LATIN_BLUE_SUB_TOP ) ) 1388 continue; 1389 if ( !( blue->flags & AF_LATIN_BLUE_ACTIVE ) ) 1390 continue; 1391 1392 for ( i = 0; i < axis->blue_count; i++ ) 1393 { 1394 AF_LatinBlue b = &axis->blues[i]; 1395 1396 1397 if ( b->flags & AF_LATIN_BLUE_SUB_TOP ) 1398 continue; 1399 if ( !( b->flags & AF_LATIN_BLUE_ACTIVE ) ) 1400 continue; 1401 1402 if ( b->ref.fit <= blue->shoot.fit && 1403 b->shoot.fit >= blue->ref.fit ) 1404 { 1405 blue->flags &= ~AF_LATIN_BLUE_ACTIVE; 1406 break; 1407 } 1408 } 1409 } 1410 1411 #ifdef FT_DEBUG_LEVEL_TRACE 1412 for ( nn = 0; nn < axis->blue_count; nn++ ) 1413 { 1414 AF_LatinBlue blue = &axis->blues[nn]; 1415 1416 1417 FT_TRACE5(( " reference %d: %d scaled to %.2f%s\n" 1418 " overshoot %d: %d scaled to %.2f%s\n", 1419 nn, 1420 blue->ref.org, 1421 blue->ref.fit / 64.0, 1422 blue->flags & AF_LATIN_BLUE_ACTIVE ? "" 1423 : " (inactive)", 1424 nn, 1425 blue->shoot.org, 1426 blue->shoot.fit / 64.0, 1427 blue->flags & AF_LATIN_BLUE_ACTIVE ? "" 1428 : " (inactive)" )); 1429 } 1430 #endif 1431 } 1432 } 1433 1434 1435 /* Scale global values in both directions. */ 1436 1437 FT_LOCAL_DEF( void ) 1438 af_latin_metrics_scale( AF_LatinMetrics metrics, 1439 AF_Scaler scaler ) 1440 { 1441 metrics->root.scaler.render_mode = scaler->render_mode; 1442 metrics->root.scaler.face = scaler->face; 1443 metrics->root.scaler.flags = scaler->flags; 1444 1445 af_latin_metrics_scale_dim( metrics, scaler, AF_DIMENSION_HORZ ); 1446 af_latin_metrics_scale_dim( metrics, scaler, AF_DIMENSION_VERT ); 1447 } 1448 1449 1450 /* Extract standard_width from writing system/script specific */ 1451 /* metrics class. */ 1452 1453 FT_LOCAL_DEF( void ) 1454 af_latin_get_standard_widths( AF_LatinMetrics metrics, 1455 FT_Pos* stdHW, 1456 FT_Pos* stdVW ) 1457 { 1458 if ( stdHW ) 1459 *stdHW = metrics->axis[AF_DIMENSION_VERT].standard_width; 1460 1461 if ( stdVW ) 1462 *stdVW = metrics->axis[AF_DIMENSION_HORZ].standard_width; 1463 } 1464 1465 1466 /*************************************************************************/ 1467 /*************************************************************************/ 1468 /***** *****/ 1469 /***** L A T I N G L Y P H A N A L Y S I S *****/ 1470 /***** *****/ 1471 /*************************************************************************/ 1472 /*************************************************************************/ 1473 1474 1475 /* Walk over all contours and compute its segments. */ 1476 1477 FT_LOCAL_DEF( FT_Error ) 1478 af_latin_hints_compute_segments( AF_GlyphHints hints, 1479 AF_Dimension dim ) 1480 { 1481 AF_LatinMetrics metrics = (AF_LatinMetrics)hints->metrics; 1482 AF_AxisHints axis = &hints->axis[dim]; 1483 FT_Memory memory = hints->memory; 1484 FT_Error error = FT_Err_Ok; 1485 AF_Segment segment = NULL; 1486 AF_SegmentRec seg0; 1487 AF_Point* contour = hints->contours; 1488 AF_Point* contour_limit = contour + hints->num_contours; 1489 AF_Direction major_dir, segment_dir; 1490 1491 FT_Pos flat_threshold = FLAT_THRESHOLD( metrics->units_per_em ); 1492 1493 1494 FT_ZERO( &seg0 ); 1495 seg0.score = 32000; 1496 seg0.flags = AF_EDGE_NORMAL; 1497 1498 major_dir = (AF_Direction)FT_ABS( axis->major_dir ); 1499 segment_dir = major_dir; 1500 1501 axis->num_segments = 0; 1502 1503 /* set up (u,v) in each point */ 1504 if ( dim == AF_DIMENSION_HORZ ) 1505 { 1506 AF_Point point = hints->points; 1507 AF_Point limit = point + hints->num_points; 1508 1509 1510 for ( ; point < limit; point++ ) 1511 { 1512 point->u = point->fx; 1513 point->v = point->fy; 1514 } 1515 } 1516 else 1517 { 1518 AF_Point point = hints->points; 1519 AF_Point limit = point + hints->num_points; 1520 1521 1522 for ( ; point < limit; point++ ) 1523 { 1524 point->u = point->fy; 1525 point->v = point->fx; 1526 } 1527 } 1528 1529 /* do each contour separately */ 1530 for ( ; contour < contour_limit; contour++ ) 1531 { 1532 AF_Point point = contour[0]; 1533 AF_Point last = point->prev; 1534 int on_edge = 0; 1535 1536 /* we call values measured along a segment (point->v) */ 1537 /* `coordinates', and values orthogonal to it (point->u) */ 1538 /* `positions' */ 1539 FT_Pos min_pos = 32000; 1540 FT_Pos max_pos = -32000; 1541 FT_Pos min_coord = 32000; 1542 FT_Pos max_coord = -32000; 1543 FT_UShort min_flags = AF_FLAG_NONE; 1544 FT_UShort max_flags = AF_FLAG_NONE; 1545 FT_Pos min_on_coord = 32000; 1546 FT_Pos max_on_coord = -32000; 1547 1548 FT_Bool passed; 1549 1550 AF_Segment prev_segment = NULL; 1551 1552 FT_Pos prev_min_pos = min_pos; 1553 FT_Pos prev_max_pos = max_pos; 1554 FT_Pos prev_min_coord = min_coord; 1555 FT_Pos prev_max_coord = max_coord; 1556 FT_UShort prev_min_flags = min_flags; 1557 FT_UShort prev_max_flags = max_flags; 1558 FT_Pos prev_min_on_coord = min_on_coord; 1559 FT_Pos prev_max_on_coord = max_on_coord; 1560 1561 1562 if ( FT_ABS( last->out_dir ) == major_dir && 1563 FT_ABS( point->out_dir ) == major_dir ) 1564 { 1565 /* we are already on an edge, try to locate its start */ 1566 last = point; 1567 1568 for (;;) 1569 { 1570 point = point->prev; 1571 if ( FT_ABS( point->out_dir ) != major_dir ) 1572 { 1573 point = point->next; 1574 break; 1575 } 1576 if ( point == last ) 1577 break; 1578 } 1579 } 1580 1581 last = point; 1582 passed = 0; 1583 1584 for (;;) 1585 { 1586 FT_Pos u, v; 1587 1588 1589 if ( on_edge ) 1590 { 1591 /* get minimum and maximum position */ 1592 u = point->u; 1593 if ( u < min_pos ) 1594 min_pos = u; 1595 if ( u > max_pos ) 1596 max_pos = u; 1597 1598 /* get minimum and maximum coordinate together with flags */ 1599 v = point->v; 1600 if ( v < min_coord ) 1601 { 1602 min_coord = v; 1603 min_flags = point->flags; 1604 } 1605 if ( v > max_coord ) 1606 { 1607 max_coord = v; 1608 max_flags = point->flags; 1609 } 1610 1611 /* get minimum and maximum coordinate of `on' points */ 1612 if ( !( point->flags & AF_FLAG_CONTROL ) ) 1613 { 1614 v = point->v; 1615 if ( v < min_on_coord ) 1616 min_on_coord = v; 1617 if ( v > max_on_coord ) 1618 max_on_coord = v; 1619 } 1620 1621 if ( point->out_dir != segment_dir || point == last ) 1622 { 1623 /* check whether the new segment's start point is identical to */ 1624 /* the previous segment's end point; for example, this might */ 1625 /* happen for spikes */ 1626 1627 if ( !prev_segment || segment->first != prev_segment->last ) 1628 { 1629 /* points are different: we are just leaving an edge, thus */ 1630 /* record a new segment */ 1631 1632 segment->last = point; 1633 segment->pos = (FT_Short)( ( min_pos + max_pos ) >> 1 ); 1634 segment->delta = (FT_Short)( ( max_pos - min_pos ) >> 1 ); 1635 1636 /* a segment is round if either its first or last point */ 1637 /* is a control point, and the length of the on points */ 1638 /* inbetween doesn't exceed a heuristic limit */ 1639 if ( ( min_flags | max_flags ) & AF_FLAG_CONTROL && 1640 ( max_on_coord - min_on_coord ) < flat_threshold ) 1641 segment->flags |= AF_EDGE_ROUND; 1642 1643 segment->min_coord = (FT_Short)min_coord; 1644 segment->max_coord = (FT_Short)max_coord; 1645 segment->height = segment->max_coord - segment->min_coord; 1646 1647 prev_segment = segment; 1648 prev_min_pos = min_pos; 1649 prev_max_pos = max_pos; 1650 prev_min_coord = min_coord; 1651 prev_max_coord = max_coord; 1652 prev_min_flags = min_flags; 1653 prev_max_flags = max_flags; 1654 prev_min_on_coord = min_on_coord; 1655 prev_max_on_coord = max_on_coord; 1656 } 1657 else 1658 { 1659 /* points are the same: we don't create a new segment but */ 1660 /* merge the current segment with the previous one */ 1661 1662 if ( prev_segment->last->in_dir == point->in_dir ) 1663 { 1664 /* we have identical directions (this can happen for */ 1665 /* degenerate outlines that move zig-zag along the main */ 1666 /* axis without changing the coordinate value of the other */ 1667 /* axis, and where the segments have just been merged): */ 1668 /* unify segments */ 1669 1670 /* update constraints */ 1671 1672 if ( prev_min_pos < min_pos ) 1673 min_pos = prev_min_pos; 1674 if ( prev_max_pos > max_pos ) 1675 max_pos = prev_max_pos; 1676 1677 if ( prev_min_coord < min_coord ) 1678 { 1679 min_coord = prev_min_coord; 1680 min_flags = prev_min_flags; 1681 } 1682 if ( prev_max_coord > max_coord ) 1683 { 1684 max_coord = prev_max_coord; 1685 max_flags = prev_max_flags; 1686 } 1687 1688 if ( prev_min_on_coord < min_on_coord ) 1689 min_on_coord = prev_min_on_coord; 1690 if ( prev_max_on_coord > max_on_coord ) 1691 max_on_coord = prev_max_on_coord; 1692 1693 prev_segment->last = point; 1694 prev_segment->pos = (FT_Short)( ( min_pos + 1695 max_pos ) >> 1 ); 1696 prev_segment->delta = (FT_Short)( ( max_pos - 1697 min_pos ) >> 1 ); 1698 1699 if ( ( min_flags | max_flags ) & AF_FLAG_CONTROL && 1700 ( max_on_coord - min_on_coord ) < flat_threshold ) 1701 prev_segment->flags |= AF_EDGE_ROUND; 1702 else 1703 prev_segment->flags &= ~AF_EDGE_ROUND; 1704 1705 prev_segment->min_coord = (FT_Short)min_coord; 1706 prev_segment->max_coord = (FT_Short)max_coord; 1707 prev_segment->height = prev_segment->max_coord - 1708 prev_segment->min_coord; 1709 } 1710 else 1711 { 1712 /* we have different directions; use the properties of the */ 1713 /* longer segment and discard the other one */ 1714 1715 if ( FT_ABS( prev_max_coord - prev_min_coord ) > 1716 FT_ABS( max_coord - min_coord ) ) 1717 { 1718 /* discard current segment */ 1719 1720 if ( min_pos < prev_min_pos ) 1721 prev_min_pos = min_pos; 1722 if ( max_pos > prev_max_pos ) 1723 prev_max_pos = max_pos; 1724 1725 prev_segment->last = point; 1726 prev_segment->pos = (FT_Short)( ( prev_min_pos + 1727 prev_max_pos ) >> 1 ); 1728 prev_segment->delta = (FT_Short)( ( prev_max_pos - 1729 prev_min_pos ) >> 1 ); 1730 } 1731 else 1732 { 1733 /* discard previous segment */ 1734 1735 if ( prev_min_pos < min_pos ) 1736 min_pos = prev_min_pos; 1737 if ( prev_max_pos > max_pos ) 1738 max_pos = prev_max_pos; 1739 1740 segment->last = point; 1741 segment->pos = (FT_Short)( ( min_pos + max_pos ) >> 1 ); 1742 segment->delta = (FT_Short)( ( max_pos - min_pos ) >> 1 ); 1743 1744 if ( ( min_flags | max_flags ) & AF_FLAG_CONTROL && 1745 ( max_on_coord - min_on_coord ) < flat_threshold ) 1746 segment->flags |= AF_EDGE_ROUND; 1747 1748 segment->min_coord = (FT_Short)min_coord; 1749 segment->max_coord = (FT_Short)max_coord; 1750 segment->height = segment->max_coord - 1751 segment->min_coord; 1752 1753 *prev_segment = *segment; 1754 1755 prev_min_pos = min_pos; 1756 prev_max_pos = max_pos; 1757 prev_min_coord = min_coord; 1758 prev_max_coord = max_coord; 1759 prev_min_flags = min_flags; 1760 prev_max_flags = max_flags; 1761 prev_min_on_coord = min_on_coord; 1762 prev_max_on_coord = max_on_coord; 1763 } 1764 } 1765 1766 axis->num_segments--; 1767 } 1768 1769 on_edge = 0; 1770 segment = NULL; 1771 1772 /* fall through */ 1773 } 1774 } 1775 1776 /* now exit if we are at the start/end point */ 1777 if ( point == last ) 1778 { 1779 if ( passed ) 1780 break; 1781 passed = 1; 1782 } 1783 1784 /* if we are not on an edge, check whether the major direction */ 1785 /* coincides with the current point's `out' direction, or */ 1786 /* whether we have a single-point contour */ 1787 if ( !on_edge && 1788 ( FT_ABS( point->out_dir ) == major_dir || 1789 point == point->prev ) ) 1790 { 1791 /* this is the start of a new segment! */ 1792 segment_dir = (AF_Direction)point->out_dir; 1793 1794 error = af_axis_hints_new_segment( axis, memory, &segment ); 1795 if ( error ) 1796 goto Exit; 1797 1798 /* clear all segment fields */ 1799 segment[0] = seg0; 1800 1801 segment->dir = (FT_Char)segment_dir; 1802 segment->first = point; 1803 segment->last = point; 1804 1805 /* `af_axis_hints_new_segment' reallocates memory, */ 1806 /* thus we have to refresh the `prev_segment' pointer */ 1807 if ( prev_segment ) 1808 prev_segment = segment - 1; 1809 1810 min_pos = max_pos = point->u; 1811 min_coord = max_coord = point->v; 1812 min_flags = max_flags = point->flags; 1813 1814 if ( point->flags & AF_FLAG_CONTROL ) 1815 { 1816 min_on_coord = 32000; 1817 max_on_coord = -32000; 1818 } 1819 else 1820 min_on_coord = max_on_coord = point->v; 1821 1822 on_edge = 1; 1823 1824 if ( point == point->prev ) 1825 { 1826 /* we have a one-point segment: this is a one-point */ 1827 /* contour with `in' and `out' direction set to */ 1828 /* AF_DIR_NONE */ 1829 segment->pos = (FT_Short)min_pos; 1830 1831 if (point->flags & AF_FLAG_CONTROL) 1832 segment->flags |= AF_EDGE_ROUND; 1833 1834 segment->min_coord = (FT_Short)point->v; 1835 segment->max_coord = (FT_Short)point->v; 1836 segment->height = 0; 1837 1838 on_edge = 0; 1839 segment = NULL; 1840 } 1841 } 1842 1843 point = point->next; 1844 } 1845 1846 } /* contours */ 1847 1848 1849 /* now slightly increase the height of segments if this makes */ 1850 /* sense -- this is used to better detect and ignore serifs */ 1851 { 1852 AF_Segment segments = axis->segments; 1853 AF_Segment segments_end = segments + axis->num_segments; 1854 1855 1856 for ( segment = segments; segment < segments_end; segment++ ) 1857 { 1858 AF_Point first = segment->first; 1859 AF_Point last = segment->last; 1860 FT_Pos first_v = first->v; 1861 FT_Pos last_v = last->v; 1862 1863 1864 if ( first_v < last_v ) 1865 { 1866 AF_Point p; 1867 1868 1869 p = first->prev; 1870 if ( p->v < first_v ) 1871 segment->height = (FT_Short)( segment->height + 1872 ( ( first_v - p->v ) >> 1 ) ); 1873 1874 p = last->next; 1875 if ( p->v > last_v ) 1876 segment->height = (FT_Short)( segment->height + 1877 ( ( p->v - last_v ) >> 1 ) ); 1878 } 1879 else 1880 { 1881 AF_Point p; 1882 1883 1884 p = first->prev; 1885 if ( p->v > first_v ) 1886 segment->height = (FT_Short)( segment->height + 1887 ( ( p->v - first_v ) >> 1 ) ); 1888 1889 p = last->next; 1890 if ( p->v < last_v ) 1891 segment->height = (FT_Short)( segment->height + 1892 ( ( last_v - p->v ) >> 1 ) ); 1893 } 1894 } 1895 } 1896 1897 Exit: 1898 return error; 1899 } 1900 1901 1902 /* Link segments to form stems and serifs. If `width_count' and */ 1903 /* `widths' are non-zero, use them to fine-tune the scoring function. */ 1904 1905 FT_LOCAL_DEF( void ) 1906 af_latin_hints_link_segments( AF_GlyphHints hints, 1907 FT_UInt width_count, 1908 AF_WidthRec* widths, 1909 AF_Dimension dim ) 1910 { 1911 AF_AxisHints axis = &hints->axis[dim]; 1912 AF_Segment segments = axis->segments; 1913 AF_Segment segment_limit = segments + axis->num_segments; 1914 FT_Pos len_threshold, len_score, dist_score, max_width; 1915 AF_Segment seg1, seg2; 1916 1917 1918 if ( width_count ) 1919 max_width = widths[width_count - 1].org; 1920 else 1921 max_width = 0; 1922 1923 /* a heuristic value to set up a minimum value for overlapping */ 1924 len_threshold = AF_LATIN_CONSTANT( hints->metrics, 8 ); 1925 if ( len_threshold == 0 ) 1926 len_threshold = 1; 1927 1928 /* a heuristic value to weight lengths */ 1929 len_score = AF_LATIN_CONSTANT( hints->metrics, 6000 ); 1930 1931 /* a heuristic value to weight distances (no call to */ 1932 /* AF_LATIN_CONSTANT needed, since we work on multiples */ 1933 /* of the stem width) */ 1934 dist_score = 3000; 1935 1936 /* now compare each segment to the others */ 1937 for ( seg1 = segments; seg1 < segment_limit; seg1++ ) 1938 { 1939 if ( seg1->dir != axis->major_dir ) 1940 continue; 1941 1942 /* search for stems having opposite directions, */ 1943 /* with seg1 to the `left' of seg2 */ 1944 for ( seg2 = segments; seg2 < segment_limit; seg2++ ) 1945 { 1946 FT_Pos pos1 = seg1->pos; 1947 FT_Pos pos2 = seg2->pos; 1948 1949 1950 if ( seg1->dir + seg2->dir == 0 && pos2 > pos1 ) 1951 { 1952 /* compute distance between the two segments */ 1953 FT_Pos min = seg1->min_coord; 1954 FT_Pos max = seg1->max_coord; 1955 FT_Pos len; 1956 1957 1958 if ( min < seg2->min_coord ) 1959 min = seg2->min_coord; 1960 1961 if ( max > seg2->max_coord ) 1962 max = seg2->max_coord; 1963 1964 /* compute maximum coordinate difference of the two segments */ 1965 /* (this is, how much they overlap) */ 1966 len = max - min; 1967 if ( len >= len_threshold ) 1968 { 1969 /* 1970 * The score is the sum of two demerits indicating the 1971 * `badness' of a fit, measured along the segments' main axis 1972 * and orthogonal to it, respectively. 1973 * 1974 * o The less overlapping along the main axis, the worse it 1975 * is, causing a larger demerit. 1976 * 1977 * o The nearer the orthogonal distance to a stem width, the 1978 * better it is, causing a smaller demerit. For simplicity, 1979 * however, we only increase the demerit for values that 1980 * exceed the largest stem width. 1981 */ 1982 1983 FT_Pos dist = pos2 - pos1; 1984 1985 FT_Pos dist_demerit, score; 1986 1987 1988 if ( max_width ) 1989 { 1990 /* distance demerits are based on multiples of `max_width'; */ 1991 /* we scale by 1024 for getting more precision */ 1992 FT_Pos delta = ( dist << 10 ) / max_width - ( 1 << 10 ); 1993 1994 1995 if ( delta > 10000 ) 1996 dist_demerit = 32000; 1997 else if ( delta > 0 ) 1998 dist_demerit = delta * delta / dist_score; 1999 else 2000 dist_demerit = 0; 2001 } 2002 else 2003 dist_demerit = dist; /* default if no widths available */ 2004 2005 score = dist_demerit + len_score / len; 2006 2007 /* and we search for the smallest score */ 2008 if ( score < seg1->score ) 2009 { 2010 seg1->score = score; 2011 seg1->link = seg2; 2012 } 2013 2014 if ( score < seg2->score ) 2015 { 2016 seg2->score = score; 2017 seg2->link = seg1; 2018 } 2019 } 2020 } 2021 } 2022 } 2023 2024 /* now compute the `serif' segments, cf. explanations in `afhints.h' */ 2025 for ( seg1 = segments; seg1 < segment_limit; seg1++ ) 2026 { 2027 seg2 = seg1->link; 2028 2029 if ( seg2 ) 2030 { 2031 if ( seg2->link != seg1 ) 2032 { 2033 seg1->link = 0; 2034 seg1->serif = seg2->link; 2035 } 2036 } 2037 } 2038 } 2039 2040 2041 /* Link segments to edges, using feature analysis for selection. */ 2042 2043 FT_LOCAL_DEF( FT_Error ) 2044 af_latin_hints_compute_edges( AF_GlyphHints hints, 2045 AF_Dimension dim ) 2046 { 2047 AF_AxisHints axis = &hints->axis[dim]; 2048 FT_Error error = FT_Err_Ok; 2049 FT_Memory memory = hints->memory; 2050 AF_LatinAxis laxis = &((AF_LatinMetrics)hints->metrics)->axis[dim]; 2051 2052 #ifdef FT_CONFIG_OPTION_PIC 2053 AF_FaceGlobals globals = hints->metrics->globals; 2054 #endif 2055 2056 AF_StyleClass style_class = hints->metrics->style_class; 2057 AF_ScriptClass script_class = AF_SCRIPT_CLASSES_GET 2058 [style_class->script]; 2059 2060 FT_Bool top_to_bottom_hinting = 0; 2061 2062 AF_Segment segments = axis->segments; 2063 AF_Segment segment_limit = segments + axis->num_segments; 2064 AF_Segment seg; 2065 2066 #if 0 2067 AF_Direction up_dir; 2068 #endif 2069 FT_Fixed scale; 2070 FT_Pos edge_distance_threshold; 2071 FT_Pos segment_length_threshold; 2072 FT_Pos segment_width_threshold; 2073 2074 2075 axis->num_edges = 0; 2076 2077 scale = ( dim == AF_DIMENSION_HORZ ) ? hints->x_scale 2078 : hints->y_scale; 2079 2080 #if 0 2081 up_dir = ( dim == AF_DIMENSION_HORZ ) ? AF_DIR_UP 2082 : AF_DIR_RIGHT; 2083 #endif 2084 2085 if ( dim == AF_DIMENSION_VERT ) 2086 top_to_bottom_hinting = script_class->top_to_bottom_hinting; 2087 2088 /* 2089 * We ignore all segments that are less than 1 pixel in length 2090 * to avoid many problems with serif fonts. We compute the 2091 * corresponding threshold in font units. 2092 */ 2093 if ( dim == AF_DIMENSION_HORZ ) 2094 segment_length_threshold = FT_DivFix( 64, hints->y_scale ); 2095 else 2096 segment_length_threshold = 0; 2097 2098 /* 2099 * Similarly, we ignore segments that have a width delta 2100 * larger than 0.5px (i.e., a width larger than 1px). 2101 */ 2102 segment_width_threshold = FT_DivFix( 32, scale ); 2103 2104 /*********************************************************************/ 2105 /* */ 2106 /* We begin by generating a sorted table of edges for the current */ 2107 /* direction. To do so, we simply scan each segment and try to find */ 2108 /* an edge in our table that corresponds to its position. */ 2109 /* */ 2110 /* If no edge is found, we create and insert a new edge in the */ 2111 /* sorted table. Otherwise, we simply add the segment to the edge's */ 2112 /* list which gets processed in the second step to compute the */ 2113 /* edge's properties. */ 2114 /* */ 2115 /* Note that the table of edges is sorted along the segment/edge */ 2116 /* position. */ 2117 /* */ 2118 /*********************************************************************/ 2119 2120 /* assure that edge distance threshold is at most 0.25px */ 2121 edge_distance_threshold = FT_MulFix( laxis->edge_distance_threshold, 2122 scale ); 2123 if ( edge_distance_threshold > 64 / 4 ) 2124 edge_distance_threshold = 64 / 4; 2125 2126 edge_distance_threshold = FT_DivFix( edge_distance_threshold, 2127 scale ); 2128 2129 for ( seg = segments; seg < segment_limit; seg++ ) 2130 { 2131 AF_Edge found = NULL; 2132 FT_Int ee; 2133 2134 2135 /* ignore too short segments, too wide ones, and, in this loop, */ 2136 /* one-point segments without a direction */ 2137 if ( seg->height < segment_length_threshold || 2138 seg->delta > segment_width_threshold || 2139 seg->dir == AF_DIR_NONE ) 2140 continue; 2141 2142 /* A special case for serif edges: If they are smaller than */ 2143 /* 1.5 pixels we ignore them. */ 2144 if ( seg->serif && 2145 2 * seg->height < 3 * segment_length_threshold ) 2146 continue; 2147 2148 /* look for an edge corresponding to the segment */ 2149 for ( ee = 0; ee < axis->num_edges; ee++ ) 2150 { 2151 AF_Edge edge = axis->edges + ee; 2152 FT_Pos dist; 2153 2154 2155 dist = seg->pos - edge->fpos; 2156 if ( dist < 0 ) 2157 dist = -dist; 2158 2159 if ( dist < edge_distance_threshold && edge->dir == seg->dir ) 2160 { 2161 found = edge; 2162 break; 2163 } 2164 } 2165 2166 if ( !found ) 2167 { 2168 AF_Edge edge; 2169 2170 2171 /* insert a new edge in the list and */ 2172 /* sort according to the position */ 2173 error = af_axis_hints_new_edge( axis, seg->pos, 2174 (AF_Direction)seg->dir, 2175 top_to_bottom_hinting, 2176 memory, &edge ); 2177 if ( error ) 2178 goto Exit; 2179 2180 /* add the segment to the new edge's list */ 2181 FT_ZERO( edge ); 2182 2183 edge->first = seg; 2184 edge->last = seg; 2185 edge->dir = seg->dir; 2186 edge->fpos = seg->pos; 2187 edge->opos = FT_MulFix( seg->pos, scale ); 2188 edge->pos = edge->opos; 2189 seg->edge_next = seg; 2190 } 2191 else 2192 { 2193 /* if an edge was found, simply add the segment to the edge's */ 2194 /* list */ 2195 seg->edge_next = found->first; 2196 found->last->edge_next = seg; 2197 found->last = seg; 2198 } 2199 } 2200 2201 /* we loop again over all segments to catch one-point segments */ 2202 /* without a direction: if possible, link them to existing edges */ 2203 for ( seg = segments; seg < segment_limit; seg++ ) 2204 { 2205 AF_Edge found = NULL; 2206 FT_Int ee; 2207 2208 2209 if ( seg->dir != AF_DIR_NONE ) 2210 continue; 2211 2212 /* look for an edge corresponding to the segment */ 2213 for ( ee = 0; ee < axis->num_edges; ee++ ) 2214 { 2215 AF_Edge edge = axis->edges + ee; 2216 FT_Pos dist; 2217 2218 2219 dist = seg->pos - edge->fpos; 2220 if ( dist < 0 ) 2221 dist = -dist; 2222 2223 if ( dist < edge_distance_threshold ) 2224 { 2225 found = edge; 2226 break; 2227 } 2228 } 2229 2230 /* one-point segments without a match are ignored */ 2231 if ( found ) 2232 { 2233 seg->edge_next = found->first; 2234 found->last->edge_next = seg; 2235 found->last = seg; 2236 } 2237 } 2238 2239 2240 /******************************************************************/ 2241 /* */ 2242 /* Good, we now compute each edge's properties according to the */ 2243 /* segments found on its position. Basically, these are */ 2244 /* */ 2245 /* - the edge's main direction */ 2246 /* - stem edge, serif edge or both (which defaults to stem then) */ 2247 /* - rounded edge, straight or both (which defaults to straight) */ 2248 /* - link for edge */ 2249 /* */ 2250 /******************************************************************/ 2251 2252 /* first of all, set the `edge' field in each segment -- this is */ 2253 /* required in order to compute edge links */ 2254 2255 /* 2256 * Note that removing this loop and setting the `edge' field of each 2257 * segment directly in the code above slows down execution speed for 2258 * some reasons on platforms like the Sun. 2259 */ 2260 { 2261 AF_Edge edges = axis->edges; 2262 AF_Edge edge_limit = edges + axis->num_edges; 2263 AF_Edge edge; 2264 2265 2266 for ( edge = edges; edge < edge_limit; edge++ ) 2267 { 2268 seg = edge->first; 2269 if ( seg ) 2270 do 2271 { 2272 seg->edge = edge; 2273 seg = seg->edge_next; 2274 2275 } while ( seg != edge->first ); 2276 } 2277 2278 /* now compute each edge properties */ 2279 for ( edge = edges; edge < edge_limit; edge++ ) 2280 { 2281 FT_Int is_round = 0; /* does it contain round segments? */ 2282 FT_Int is_straight = 0; /* does it contain straight segments? */ 2283 #if 0 2284 FT_Pos ups = 0; /* number of upwards segments */ 2285 FT_Pos downs = 0; /* number of downwards segments */ 2286 #endif 2287 2288 2289 seg = edge->first; 2290 2291 do 2292 { 2293 FT_Bool is_serif; 2294 2295 2296 /* check for roundness of segment */ 2297 if ( seg->flags & AF_EDGE_ROUND ) 2298 is_round++; 2299 else 2300 is_straight++; 2301 2302 #if 0 2303 /* check for segment direction */ 2304 if ( seg->dir == up_dir ) 2305 ups += seg->max_coord - seg->min_coord; 2306 else 2307 downs += seg->max_coord - seg->min_coord; 2308 #endif 2309 2310 /* check for links -- if seg->serif is set, then seg->link must */ 2311 /* be ignored */ 2312 is_serif = (FT_Bool)( seg->serif && 2313 seg->serif->edge && 2314 seg->serif->edge != edge ); 2315 2316 if ( ( seg->link && seg->link->edge ) || is_serif ) 2317 { 2318 AF_Edge edge2; 2319 AF_Segment seg2; 2320 2321 2322 edge2 = edge->link; 2323 seg2 = seg->link; 2324 2325 if ( is_serif ) 2326 { 2327 seg2 = seg->serif; 2328 edge2 = edge->serif; 2329 } 2330 2331 if ( edge2 ) 2332 { 2333 FT_Pos edge_delta; 2334 FT_Pos seg_delta; 2335 2336 2337 edge_delta = edge->fpos - edge2->fpos; 2338 if ( edge_delta < 0 ) 2339 edge_delta = -edge_delta; 2340 2341 seg_delta = seg->pos - seg2->pos; 2342 if ( seg_delta < 0 ) 2343 seg_delta = -seg_delta; 2344 2345 if ( seg_delta < edge_delta ) 2346 edge2 = seg2->edge; 2347 } 2348 else 2349 edge2 = seg2->edge; 2350 2351 if ( is_serif ) 2352 { 2353 edge->serif = edge2; 2354 edge2->flags |= AF_EDGE_SERIF; 2355 } 2356 else 2357 edge->link = edge2; 2358 } 2359 2360 seg = seg->edge_next; 2361 2362 } while ( seg != edge->first ); 2363 2364 /* set the round/straight flags */ 2365 edge->flags = AF_EDGE_NORMAL; 2366 2367 if ( is_round > 0 && is_round >= is_straight ) 2368 edge->flags |= AF_EDGE_ROUND; 2369 2370 #if 0 2371 /* set the edge's main direction */ 2372 edge->dir = AF_DIR_NONE; 2373 2374 if ( ups > downs ) 2375 edge->dir = (FT_Char)up_dir; 2376 2377 else if ( ups < downs ) 2378 edge->dir = (FT_Char)-up_dir; 2379 2380 else if ( ups == downs ) 2381 edge->dir = 0; /* both up and down! */ 2382 #endif 2383 2384 /* get rid of serifs if link is set */ 2385 /* XXX: This gets rid of many unpleasant artefacts! */ 2386 /* Example: the `c' in cour.pfa at size 13 */ 2387 2388 if ( edge->serif && edge->link ) 2389 edge->serif = NULL; 2390 } 2391 } 2392 2393 Exit: 2394 return error; 2395 } 2396 2397 2398 /* Detect segments and edges for given dimension. */ 2399 2400 FT_LOCAL_DEF( FT_Error ) 2401 af_latin_hints_detect_features( AF_GlyphHints hints, 2402 FT_UInt width_count, 2403 AF_WidthRec* widths, 2404 AF_Dimension dim ) 2405 { 2406 FT_Error error; 2407 2408 2409 error = af_latin_hints_compute_segments( hints, dim ); 2410 if ( !error ) 2411 { 2412 af_latin_hints_link_segments( hints, width_count, widths, dim ); 2413 2414 error = af_latin_hints_compute_edges( hints, dim ); 2415 } 2416 2417 return error; 2418 } 2419 2420 2421 /* Compute all edges which lie within blue zones. */ 2422 2423 static void 2424 af_latin_hints_compute_blue_edges( AF_GlyphHints hints, 2425 AF_LatinMetrics metrics ) 2426 { 2427 AF_AxisHints axis = &hints->axis[AF_DIMENSION_VERT]; 2428 AF_Edge edge = axis->edges; 2429 AF_Edge edge_limit = edge + axis->num_edges; 2430 AF_LatinAxis latin = &metrics->axis[AF_DIMENSION_VERT]; 2431 FT_Fixed scale = latin->scale; 2432 2433 2434 /* compute which blue zones are active, i.e. have their scaled */ 2435 /* size < 3/4 pixels */ 2436 2437 /* for each horizontal edge search the blue zone which is closest */ 2438 for ( ; edge < edge_limit; edge++ ) 2439 { 2440 FT_UInt bb; 2441 AF_Width best_blue = NULL; 2442 FT_Bool best_blue_is_neutral = 0; 2443 FT_Pos best_dist; /* initial threshold */ 2444 2445 2446 /* compute the initial threshold as a fraction of the EM size */ 2447 /* (the value 40 is heuristic) */ 2448 best_dist = FT_MulFix( metrics->units_per_em / 40, scale ); 2449 2450 /* assure a minimum distance of 0.5px */ 2451 if ( best_dist > 64 / 2 ) 2452 best_dist = 64 / 2; 2453 2454 for ( bb = 0; bb < latin->blue_count; bb++ ) 2455 { 2456 AF_LatinBlue blue = latin->blues + bb; 2457 FT_Bool is_top_blue, is_neutral_blue, is_major_dir; 2458 2459 2460 /* skip inactive blue zones (i.e., those that are too large) */ 2461 if ( !( blue->flags & AF_LATIN_BLUE_ACTIVE ) ) 2462 continue; 2463 2464 /* if it is a top zone, check for right edges (against the major */ 2465 /* direction); if it is a bottom zone, check for left edges (in */ 2466 /* the major direction) -- this assumes the TrueType convention */ 2467 /* for the orientation of contours */ 2468 is_top_blue = 2469 (FT_Byte)( ( blue->flags & ( AF_LATIN_BLUE_TOP | 2470 AF_LATIN_BLUE_SUB_TOP ) ) != 0 ); 2471 is_neutral_blue = 2472 (FT_Byte)( ( blue->flags & AF_LATIN_BLUE_NEUTRAL ) != 0); 2473 is_major_dir = 2474 FT_BOOL( edge->dir == axis->major_dir ); 2475 2476 /* neutral blue zones are handled for both directions */ 2477 if ( is_top_blue ^ is_major_dir || is_neutral_blue ) 2478 { 2479 FT_Pos dist; 2480 2481 2482 /* first of all, compare it to the reference position */ 2483 dist = edge->fpos - blue->ref.org; 2484 if ( dist < 0 ) 2485 dist = -dist; 2486 2487 dist = FT_MulFix( dist, scale ); 2488 if ( dist < best_dist ) 2489 { 2490 best_dist = dist; 2491 best_blue = &blue->ref; 2492 best_blue_is_neutral = is_neutral_blue; 2493 } 2494 2495 /* now compare it to the overshoot position and check whether */ 2496 /* the edge is rounded, and whether the edge is over the */ 2497 /* reference position of a top zone, or under the reference */ 2498 /* position of a bottom zone (provided we don't have a */ 2499 /* neutral blue zone) */ 2500 if ( edge->flags & AF_EDGE_ROUND && 2501 dist != 0 && 2502 !is_neutral_blue ) 2503 { 2504 FT_Bool is_under_ref = FT_BOOL( edge->fpos < blue->ref.org ); 2505 2506 2507 if ( is_top_blue ^ is_under_ref ) 2508 { 2509 dist = edge->fpos - blue->shoot.org; 2510 if ( dist < 0 ) 2511 dist = -dist; 2512 2513 dist = FT_MulFix( dist, scale ); 2514 if ( dist < best_dist ) 2515 { 2516 best_dist = dist; 2517 best_blue = &blue->shoot; 2518 best_blue_is_neutral = is_neutral_blue; 2519 } 2520 } 2521 } 2522 } 2523 } 2524 2525 if ( best_blue ) 2526 { 2527 edge->blue_edge = best_blue; 2528 if ( best_blue_is_neutral ) 2529 edge->flags |= AF_EDGE_NEUTRAL; 2530 } 2531 } 2532 } 2533 2534 2535 /* Initalize hinting engine. */ 2536 2537 static FT_Error 2538 af_latin_hints_init( AF_GlyphHints hints, 2539 AF_LatinMetrics metrics ) 2540 { 2541 FT_Render_Mode mode; 2542 FT_UInt32 scaler_flags, other_flags; 2543 FT_Face face = metrics->root.scaler.face; 2544 2545 2546 af_glyph_hints_rescale( hints, (AF_StyleMetrics)metrics ); 2547 2548 /* 2549 * correct x_scale and y_scale if needed, since they may have 2550 * been modified by `af_latin_metrics_scale_dim' above 2551 */ 2552 hints->x_scale = metrics->axis[AF_DIMENSION_HORZ].scale; 2553 hints->x_delta = metrics->axis[AF_DIMENSION_HORZ].delta; 2554 hints->y_scale = metrics->axis[AF_DIMENSION_VERT].scale; 2555 hints->y_delta = metrics->axis[AF_DIMENSION_VERT].delta; 2556 2557 /* compute flags depending on render mode, etc. */ 2558 mode = metrics->root.scaler.render_mode; 2559 2560 #if 0 /* #ifdef AF_CONFIG_OPTION_USE_WARPER */ 2561 if ( mode == FT_RENDER_MODE_LCD || mode == FT_RENDER_MODE_LCD_V ) 2562 metrics->root.scaler.render_mode = mode = FT_RENDER_MODE_NORMAL; 2563 #endif 2564 2565 scaler_flags = hints->scaler_flags; 2566 other_flags = 0; 2567 2568 /* 2569 * We snap the width of vertical stems for the monochrome and 2570 * horizontal LCD rendering targets only. 2571 */ 2572 if ( mode == FT_RENDER_MODE_MONO || mode == FT_RENDER_MODE_LCD ) 2573 other_flags |= AF_LATIN_HINTS_HORZ_SNAP; 2574 2575 /* 2576 * We snap the width of horizontal stems for the monochrome and 2577 * vertical LCD rendering targets only. 2578 */ 2579 if ( mode == FT_RENDER_MODE_MONO || mode == FT_RENDER_MODE_LCD_V ) 2580 other_flags |= AF_LATIN_HINTS_VERT_SNAP; 2581 2582 /* 2583 * We adjust stems to full pixels unless in `light' or `lcd' mode. 2584 */ 2585 if ( mode != FT_RENDER_MODE_LIGHT && mode != FT_RENDER_MODE_LCD ) 2586 other_flags |= AF_LATIN_HINTS_STEM_ADJUST; 2587 2588 if ( mode == FT_RENDER_MODE_MONO ) 2589 other_flags |= AF_LATIN_HINTS_MONO; 2590 2591 /* 2592 * In `light' or `lcd' mode we disable horizontal hinting completely. 2593 * We also do it if the face is italic. 2594 * 2595 * However, if warping is enabled (which only works in `light' hinting 2596 * mode), advance widths get adjusted, too. 2597 */ 2598 if ( mode == FT_RENDER_MODE_LIGHT || mode == FT_RENDER_MODE_LCD || 2599 ( face->style_flags & FT_STYLE_FLAG_ITALIC ) != 0 ) 2600 scaler_flags |= AF_SCALER_FLAG_NO_HORIZONTAL; 2601 2602 #ifdef AF_CONFIG_OPTION_USE_WARPER 2603 /* get (global) warper flag */ 2604 if ( !metrics->root.globals->module->warping ) 2605 scaler_flags |= AF_SCALER_FLAG_NO_WARPER; 2606 #endif 2607 2608 hints->scaler_flags = scaler_flags; 2609 hints->other_flags = other_flags; 2610 2611 return FT_Err_Ok; 2612 } 2613 2614 2615 /*************************************************************************/ 2616 /*************************************************************************/ 2617 /***** *****/ 2618 /***** L A T I N G L Y P H G R I D - F I T T I N G *****/ 2619 /***** *****/ 2620 /*************************************************************************/ 2621 /*************************************************************************/ 2622 2623 /* Snap a given width in scaled coordinates to one of the */ 2624 /* current standard widths. */ 2625 2626 static FT_Pos 2627 af_latin_snap_width( AF_Width widths, 2628 FT_UInt count, 2629 FT_Pos width ) 2630 { 2631 FT_UInt n; 2632 FT_Pos best = 64 + 32 + 2; 2633 FT_Pos reference = width; 2634 FT_Pos scaled; 2635 2636 2637 for ( n = 0; n < count; n++ ) 2638 { 2639 FT_Pos w; 2640 FT_Pos dist; 2641 2642 2643 w = widths[n].cur; 2644 dist = width - w; 2645 if ( dist < 0 ) 2646 dist = -dist; 2647 if ( dist < best ) 2648 { 2649 best = dist; 2650 reference = w; 2651 } 2652 } 2653 2654 scaled = FT_PIX_ROUND( reference ); 2655 2656 if ( width >= reference ) 2657 { 2658 if ( width < scaled + 48 ) 2659 width = reference; 2660 } 2661 else 2662 { 2663 if ( width > scaled - 48 ) 2664 width = reference; 2665 } 2666 2667 return width; 2668 } 2669 2670 2671 /* Compute the snapped width of a given stem, ignoring very thin ones. */ 2672 /* There is a lot of voodoo in this function; changing the hard-coded */ 2673 /* parameters influence the whole hinting process. */ 2674 2675 static FT_Pos 2676 af_latin_compute_stem_width( AF_GlyphHints hints, 2677 AF_Dimension dim, 2678 FT_Pos width, 2679 FT_Pos base_delta, 2680 FT_UInt base_flags, 2681 FT_UInt stem_flags ) 2682 { 2683 AF_LatinMetrics metrics = (AF_LatinMetrics)hints->metrics; 2684 AF_LatinAxis axis = &metrics->axis[dim]; 2685 FT_Pos dist = width; 2686 FT_Int sign = 0; 2687 FT_Int vertical = ( dim == AF_DIMENSION_VERT ); 2688 2689 2690 if ( !AF_LATIN_HINTS_DO_STEM_ADJUST( hints ) || 2691 axis->extra_light ) 2692 return width; 2693 2694 if ( dist < 0 ) 2695 { 2696 dist = -width; 2697 sign = 1; 2698 } 2699 2700 if ( ( vertical && !AF_LATIN_HINTS_DO_VERT_SNAP( hints ) ) || 2701 ( !vertical && !AF_LATIN_HINTS_DO_HORZ_SNAP( hints ) ) ) 2702 { 2703 /* smooth hinting process: very lightly quantize the stem width */ 2704 2705 /* leave the widths of serifs alone */ 2706 if ( ( stem_flags & AF_EDGE_SERIF ) && 2707 vertical && 2708 ( dist < 3 * 64 ) ) 2709 goto Done_Width; 2710 2711 else if ( base_flags & AF_EDGE_ROUND ) 2712 { 2713 if ( dist < 80 ) 2714 dist = 64; 2715 } 2716 else if ( dist < 56 ) 2717 dist = 56; 2718 2719 if ( axis->width_count > 0 ) 2720 { 2721 FT_Pos delta; 2722 2723 2724 /* compare to standard width */ 2725 delta = dist - axis->widths[0].cur; 2726 2727 if ( delta < 0 ) 2728 delta = -delta; 2729 2730 if ( delta < 40 ) 2731 { 2732 dist = axis->widths[0].cur; 2733 if ( dist < 48 ) 2734 dist = 48; 2735 2736 goto Done_Width; 2737 } 2738 2739 if ( dist < 3 * 64 ) 2740 { 2741 delta = dist & 63; 2742 dist &= -64; 2743 2744 if ( delta < 10 ) 2745 dist += delta; 2746 2747 else if ( delta < 32 ) 2748 dist += 10; 2749 2750 else if ( delta < 54 ) 2751 dist += 54; 2752 2753 else 2754 dist += delta; 2755 } 2756 else 2757 { 2758 /* A stem's end position depends on two values: the start */ 2759 /* position and the stem length. The former gets usually */ 2760 /* rounded to the grid, while the latter gets rounded also if it */ 2761 /* exceeds a certain length (see below in this function). This */ 2762 /* `double rounding' can lead to a great difference to the */ 2763 /* original, unhinted position; this normally doesn't matter for */ 2764 /* large PPEM values, but for small sizes it can easily make */ 2765 /* outlines collide. For this reason, we adjust the stem length */ 2766 /* by a small amount depending on the PPEM value in case the */ 2767 /* former and latter rounding both point into the same */ 2768 /* direction. */ 2769 2770 FT_Pos bdelta = 0; 2771 2772 2773 if ( ( ( width > 0 ) && ( base_delta > 0 ) ) || 2774 ( ( width < 0 ) && ( base_delta < 0 ) ) ) 2775 { 2776 FT_UInt ppem = metrics->root.scaler.face->size->metrics.x_ppem; 2777 2778 2779 if ( ppem < 10 ) 2780 bdelta = base_delta; 2781 else if ( ppem < 30 ) 2782 bdelta = ( base_delta * (FT_Pos)( 30 - ppem ) ) / 20; 2783 2784 if ( bdelta < 0 ) 2785 bdelta = -bdelta; 2786 } 2787 2788 dist = ( dist - bdelta + 32 ) & ~63; 2789 } 2790 } 2791 } 2792 else 2793 { 2794 /* strong hinting process: snap the stem width to integer pixels */ 2795 2796 FT_Pos org_dist = dist; 2797 2798 2799 dist = af_latin_snap_width( axis->widths, axis->width_count, dist ); 2800 2801 if ( vertical ) 2802 { 2803 /* in the case of vertical hinting, always round */ 2804 /* the stem heights to integer pixels */ 2805 2806 if ( dist >= 64 ) 2807 dist = ( dist + 16 ) & ~63; 2808 else 2809 dist = 64; 2810 } 2811 else 2812 { 2813 if ( AF_LATIN_HINTS_DO_MONO( hints ) ) 2814 { 2815 /* monochrome horizontal hinting: snap widths to integer pixels */ 2816 /* with a different threshold */ 2817 2818 if ( dist < 64 ) 2819 dist = 64; 2820 else 2821 dist = ( dist + 32 ) & ~63; 2822 } 2823 else 2824 { 2825 /* for horizontal anti-aliased hinting, we adopt a more subtle */ 2826 /* approach: we strengthen small stems, round stems whose size */ 2827 /* is between 1 and 2 pixels to an integer, otherwise nothing */ 2828 2829 if ( dist < 48 ) 2830 dist = ( dist + 64 ) >> 1; 2831 2832 else if ( dist < 128 ) 2833 { 2834 /* We only round to an integer width if the corresponding */ 2835 /* distortion is less than 1/4 pixel. Otherwise this */ 2836 /* makes everything worse since the diagonals, which are */ 2837 /* not hinted, appear a lot bolder or thinner than the */ 2838 /* vertical stems. */ 2839 2840 FT_Pos delta; 2841 2842 2843 dist = ( dist + 22 ) & ~63; 2844 delta = dist - org_dist; 2845 if ( delta < 0 ) 2846 delta = -delta; 2847 2848 if ( delta >= 16 ) 2849 { 2850 dist = org_dist; 2851 if ( dist < 48 ) 2852 dist = ( dist + 64 ) >> 1; 2853 } 2854 } 2855 else 2856 /* round otherwise to prevent color fringes in LCD mode */ 2857 dist = ( dist + 32 ) & ~63; 2858 } 2859 } 2860 } 2861 2862 Done_Width: 2863 if ( sign ) 2864 dist = -dist; 2865 2866 return dist; 2867 } 2868 2869 2870 /* Align one stem edge relative to the previous stem edge. */ 2871 2872 static void 2873 af_latin_align_linked_edge( AF_GlyphHints hints, 2874 AF_Dimension dim, 2875 AF_Edge base_edge, 2876 AF_Edge stem_edge ) 2877 { 2878 FT_Pos dist, base_delta; 2879 FT_Pos fitted_width; 2880 2881 2882 dist = stem_edge->opos - base_edge->opos; 2883 base_delta = base_edge->pos - base_edge->opos; 2884 2885 fitted_width = af_latin_compute_stem_width( hints, dim, 2886 dist, base_delta, 2887 base_edge->flags, 2888 stem_edge->flags ); 2889 2890 2891 stem_edge->pos = base_edge->pos + fitted_width; 2892 2893 FT_TRACE5(( " LINK: edge %d (opos=%.2f) linked to %.2f," 2894 " dist was %.2f, now %.2f\n", 2895 stem_edge - hints->axis[dim].edges, stem_edge->opos / 64.0, 2896 stem_edge->pos / 64.0, dist / 64.0, fitted_width / 64.0 )); 2897 } 2898 2899 2900 /* Shift the coordinates of the `serif' edge by the same amount */ 2901 /* as the corresponding `base' edge has been moved already. */ 2902 2903 static void 2904 af_latin_align_serif_edge( AF_GlyphHints hints, 2905 AF_Edge base, 2906 AF_Edge serif ) 2907 { 2908 FT_UNUSED( hints ); 2909 2910 serif->pos = base->pos + ( serif->opos - base->opos ); 2911 } 2912 2913 2914 /*************************************************************************/ 2915 /*************************************************************************/ 2916 /*************************************************************************/ 2917 /**** ****/ 2918 /**** E D G E H I N T I N G ****/ 2919 /**** ****/ 2920 /*************************************************************************/ 2921 /*************************************************************************/ 2922 /*************************************************************************/ 2923 2924 2925 /* The main grid-fitting routine. */ 2926 2927 static void 2928 af_latin_hint_edges( AF_GlyphHints hints, 2929 AF_Dimension dim ) 2930 { 2931 AF_AxisHints axis = &hints->axis[dim]; 2932 AF_Edge edges = axis->edges; 2933 AF_Edge edge_limit = edges + axis->num_edges; 2934 FT_PtrDist n_edges; 2935 AF_Edge edge; 2936 AF_Edge anchor = NULL; 2937 FT_Int has_serifs = 0; 2938 2939 #ifdef FT_CONFIG_OPTION_PIC 2940 AF_FaceGlobals globals = hints->metrics->globals; 2941 #endif 2942 2943 AF_StyleClass style_class = hints->metrics->style_class; 2944 AF_ScriptClass script_class = AF_SCRIPT_CLASSES_GET 2945 [style_class->script]; 2946 2947 FT_Bool top_to_bottom_hinting = 0; 2948 2949 #ifdef FT_DEBUG_LEVEL_TRACE 2950 FT_UInt num_actions = 0; 2951 #endif 2952 2953 2954 FT_TRACE5(( "latin %s edge hinting (style `%s')\n", 2955 dim == AF_DIMENSION_VERT ? "horizontal" : "vertical", 2956 af_style_names[hints->metrics->style_class->style] )); 2957 2958 if ( dim == AF_DIMENSION_VERT ) 2959 top_to_bottom_hinting = script_class->top_to_bottom_hinting; 2960 2961 /* we begin by aligning all stems relative to the blue zone */ 2962 /* if needed -- that's only for horizontal edges */ 2963 2964 if ( dim == AF_DIMENSION_VERT && AF_HINTS_DO_BLUES( hints ) ) 2965 { 2966 for ( edge = edges; edge < edge_limit; edge++ ) 2967 { 2968 AF_Width blue; 2969 AF_Edge edge1, edge2; /* these edges form the stem to check */ 2970 2971 2972 if ( edge->flags & AF_EDGE_DONE ) 2973 continue; 2974 2975 edge1 = NULL; 2976 edge2 = edge->link; 2977 2978 /* 2979 * If a stem contains both a neutral and a non-neutral blue zone, 2980 * skip the neutral one. Otherwise, outlines with different 2981 * directions might be incorrectly aligned at the same vertical 2982 * position. 2983 * 2984 * If we have two neutral blue zones, skip one of them. 2985 * 2986 */ 2987 if ( edge->blue_edge && edge2 && edge2->blue_edge ) 2988 { 2989 FT_Byte neutral = edge->flags & AF_EDGE_NEUTRAL; 2990 FT_Byte neutral2 = edge2->flags & AF_EDGE_NEUTRAL; 2991 2992 2993 if ( neutral2 ) 2994 { 2995 edge2->blue_edge = NULL; 2996 edge2->flags &= ~AF_EDGE_NEUTRAL; 2997 } 2998 else if ( neutral ) 2999 { 3000 edge->blue_edge = NULL; 3001 edge->flags &= ~AF_EDGE_NEUTRAL; 3002 } 3003 } 3004 3005 blue = edge->blue_edge; 3006 if ( blue ) 3007 edge1 = edge; 3008 3009 /* flip edges if the other edge is aligned to a blue zone */ 3010 else if ( edge2 && edge2->blue_edge ) 3011 { 3012 blue = edge2->blue_edge; 3013 edge1 = edge2; 3014 edge2 = edge; 3015 } 3016 3017 if ( !edge1 ) 3018 continue; 3019 3020 #ifdef FT_DEBUG_LEVEL_TRACE 3021 if ( !anchor ) 3022 FT_TRACE5(( " BLUE_ANCHOR: edge %d (opos=%.2f) snapped to %.2f," 3023 " was %.2f (anchor=edge %d)\n", 3024 edge1 - edges, edge1->opos / 64.0, blue->fit / 64.0, 3025 edge1->pos / 64.0, edge - edges )); 3026 else 3027 FT_TRACE5(( " BLUE: edge %d (opos=%.2f) snapped to %.2f," 3028 " was %.2f\n", 3029 edge1 - edges, edge1->opos / 64.0, blue->fit / 64.0, 3030 edge1->pos / 64.0 )); 3031 3032 num_actions++; 3033 #endif 3034 3035 edge1->pos = blue->fit; 3036 edge1->flags |= AF_EDGE_DONE; 3037 3038 if ( edge2 && !edge2->blue_edge ) 3039 { 3040 af_latin_align_linked_edge( hints, dim, edge1, edge2 ); 3041 edge2->flags |= AF_EDGE_DONE; 3042 3043 #ifdef FT_DEBUG_LEVEL_TRACE 3044 num_actions++; 3045 #endif 3046 } 3047 3048 if ( !anchor ) 3049 anchor = edge; 3050 } 3051 } 3052 3053 /* now we align all other stem edges, trying to maintain the */ 3054 /* relative order of stems in the glyph */ 3055 for ( edge = edges; edge < edge_limit; edge++ ) 3056 { 3057 AF_Edge edge2; 3058 3059 3060 if ( edge->flags & AF_EDGE_DONE ) 3061 continue; 3062 3063 /* skip all non-stem edges */ 3064 edge2 = edge->link; 3065 if ( !edge2 ) 3066 { 3067 has_serifs++; 3068 continue; 3069 } 3070 3071 /* now align the stem */ 3072 3073 /* this should not happen, but it's better to be safe */ 3074 if ( edge2->blue_edge ) 3075 { 3076 FT_TRACE5(( " ASSERTION FAILED for edge %d\n", edge2 - edges )); 3077 3078 af_latin_align_linked_edge( hints, dim, edge2, edge ); 3079 edge->flags |= AF_EDGE_DONE; 3080 3081 #ifdef FT_DEBUG_LEVEL_TRACE 3082 num_actions++; 3083 #endif 3084 continue; 3085 } 3086 3087 if ( !anchor ) 3088 { 3089 /* if we reach this if clause, no stem has been aligned yet */ 3090 3091 FT_Pos org_len, org_center, cur_len; 3092 FT_Pos cur_pos1, error1, error2, u_off, d_off; 3093 3094 3095 org_len = edge2->opos - edge->opos; 3096 cur_len = af_latin_compute_stem_width( hints, dim, 3097 org_len, 0, 3098 edge->flags, 3099 edge2->flags ); 3100 3101 /* some voodoo to specially round edges for small stem widths; */ 3102 /* the idea is to align the center of a stem, then shifting */ 3103 /* the stem edges to suitable positions */ 3104 if ( cur_len <= 64 ) 3105 { 3106 /* width <= 1px */ 3107 u_off = 32; 3108 d_off = 32; 3109 } 3110 else 3111 { 3112 /* 1px < width < 1.5px */ 3113 u_off = 38; 3114 d_off = 26; 3115 } 3116 3117 if ( cur_len < 96 ) 3118 { 3119 org_center = edge->opos + ( org_len >> 1 ); 3120 cur_pos1 = FT_PIX_ROUND( org_center ); 3121 3122 error1 = org_center - ( cur_pos1 - u_off ); 3123 if ( error1 < 0 ) 3124 error1 = -error1; 3125 3126 error2 = org_center - ( cur_pos1 + d_off ); 3127 if ( error2 < 0 ) 3128 error2 = -error2; 3129 3130 if ( error1 < error2 ) 3131 cur_pos1 -= u_off; 3132 else 3133 cur_pos1 += d_off; 3134 3135 edge->pos = cur_pos1 - cur_len / 2; 3136 edge2->pos = edge->pos + cur_len; 3137 } 3138 else 3139 edge->pos = FT_PIX_ROUND( edge->opos ); 3140 3141 anchor = edge; 3142 edge->flags |= AF_EDGE_DONE; 3143 3144 FT_TRACE5(( " ANCHOR: edge %d (opos=%.2f) and %d (opos=%.2f)" 3145 " snapped to %.2f and %.2f\n", 3146 edge - edges, edge->opos / 64.0, 3147 edge2 - edges, edge2->opos / 64.0, 3148 edge->pos / 64.0, edge2->pos / 64.0 )); 3149 3150 af_latin_align_linked_edge( hints, dim, edge, edge2 ); 3151 3152 #ifdef FT_DEBUG_LEVEL_TRACE 3153 num_actions += 2; 3154 #endif 3155 } 3156 else 3157 { 3158 FT_Pos org_pos, org_len, org_center, cur_len; 3159 FT_Pos cur_pos1, cur_pos2, delta1, delta2; 3160 3161 3162 org_pos = anchor->pos + ( edge->opos - anchor->opos ); 3163 org_len = edge2->opos - edge->opos; 3164 org_center = org_pos + ( org_len >> 1 ); 3165 3166 cur_len = af_latin_compute_stem_width( hints, dim, 3167 org_len, 0, 3168 edge->flags, 3169 edge2->flags ); 3170 3171 if ( edge2->flags & AF_EDGE_DONE ) 3172 { 3173 FT_TRACE5(( " ADJUST: edge %d (pos=%.2f) moved to %.2f\n", 3174 edge - edges, edge->pos / 64.0, 3175 ( edge2->pos - cur_len ) / 64.0 )); 3176 3177 edge->pos = edge2->pos - cur_len; 3178 } 3179 3180 else if ( cur_len < 96 ) 3181 { 3182 FT_Pos u_off, d_off; 3183 3184 3185 cur_pos1 = FT_PIX_ROUND( org_center ); 3186 3187 if ( cur_len <= 64 ) 3188 { 3189 u_off = 32; 3190 d_off = 32; 3191 } 3192 else 3193 { 3194 u_off = 38; 3195 d_off = 26; 3196 } 3197 3198 delta1 = org_center - ( cur_pos1 - u_off ); 3199 if ( delta1 < 0 ) 3200 delta1 = -delta1; 3201 3202 delta2 = org_center - ( cur_pos1 + d_off ); 3203 if ( delta2 < 0 ) 3204 delta2 = -delta2; 3205 3206 if ( delta1 < delta2 ) 3207 cur_pos1 -= u_off; 3208 else 3209 cur_pos1 += d_off; 3210 3211 edge->pos = cur_pos1 - cur_len / 2; 3212 edge2->pos = cur_pos1 + cur_len / 2; 3213 3214 FT_TRACE5(( " STEM: edge %d (opos=%.2f) linked to %d (opos=%.2f)" 3215 " snapped to %.2f and %.2f\n", 3216 edge - edges, edge->opos / 64.0, 3217 edge2 - edges, edge2->opos / 64.0, 3218 edge->pos / 64.0, edge2->pos / 64.0 )); 3219 } 3220 3221 else 3222 { 3223 org_pos = anchor->pos + ( edge->opos - anchor->opos ); 3224 org_len = edge2->opos - edge->opos; 3225 org_center = org_pos + ( org_len >> 1 ); 3226 3227 cur_len = af_latin_compute_stem_width( hints, dim, 3228 org_len, 0, 3229 edge->flags, 3230 edge2->flags ); 3231 3232 cur_pos1 = FT_PIX_ROUND( org_pos ); 3233 delta1 = cur_pos1 + ( cur_len >> 1 ) - org_center; 3234 if ( delta1 < 0 ) 3235 delta1 = -delta1; 3236 3237 cur_pos2 = FT_PIX_ROUND( org_pos + org_len ) - cur_len; 3238 delta2 = cur_pos2 + ( cur_len >> 1 ) - org_center; 3239 if ( delta2 < 0 ) 3240 delta2 = -delta2; 3241 3242 edge->pos = ( delta1 < delta2 ) ? cur_pos1 : cur_pos2; 3243 edge2->pos = edge->pos + cur_len; 3244 3245 FT_TRACE5(( " STEM: edge %d (opos=%.2f) linked to %d (opos=%.2f)" 3246 " snapped to %.2f and %.2f\n", 3247 edge - edges, edge->opos / 64.0, 3248 edge2 - edges, edge2->opos / 64.0, 3249 edge->pos / 64.0, edge2->pos / 64.0 )); 3250 } 3251 3252 #ifdef FT_DEBUG_LEVEL_TRACE 3253 num_actions++; 3254 #endif 3255 3256 edge->flags |= AF_EDGE_DONE; 3257 edge2->flags |= AF_EDGE_DONE; 3258 3259 if ( edge > edges && 3260 ( top_to_bottom_hinting ? ( edge->pos > edge[-1].pos ) 3261 : ( edge->pos < edge[-1].pos ) ) ) 3262 { 3263 /* don't move if stem would (almost) disappear otherwise; */ 3264 /* the ad-hoc value 16 corresponds to 1/4px */ 3265 if ( edge->link && FT_ABS( edge->link->pos - edge[-1].pos ) > 16 ) 3266 { 3267 #ifdef FT_DEBUG_LEVEL_TRACE 3268 FT_TRACE5(( " BOUND: edge %d (pos=%.2f) moved to %.2f\n", 3269 edge - edges, 3270 edge->pos / 64.0, 3271 edge[-1].pos / 64.0 )); 3272 3273 num_actions++; 3274 #endif 3275 3276 edge->pos = edge[-1].pos; 3277 } 3278 } 3279 } 3280 } 3281 3282 /* make sure that lowercase m's maintain their symmetry */ 3283 3284 /* In general, lowercase m's have six vertical edges if they are sans */ 3285 /* serif, or twelve if they are with serifs. This implementation is */ 3286 /* based on that assumption, and seems to work very well with most */ 3287 /* faces. However, if for a certain face this assumption is not */ 3288 /* true, the m is just rendered like before. In addition, any stem */ 3289 /* correction will only be applied to symmetrical glyphs (even if the */ 3290 /* glyph is not an m), so the potential for unwanted distortion is */ 3291 /* relatively low. */ 3292 3293 /* We don't handle horizontal edges since we can't easily assure that */ 3294 /* the third (lowest) stem aligns with the base line; it might end up */ 3295 /* one pixel higher or lower. */ 3296 3297 n_edges = edge_limit - edges; 3298 if ( dim == AF_DIMENSION_HORZ && ( n_edges == 6 || n_edges == 12 ) ) 3299 { 3300 AF_Edge edge1, edge2, edge3; 3301 FT_Pos dist1, dist2, span, delta; 3302 3303 3304 if ( n_edges == 6 ) 3305 { 3306 edge1 = edges; 3307 edge2 = edges + 2; 3308 edge3 = edges + 4; 3309 } 3310 else 3311 { 3312 edge1 = edges + 1; 3313 edge2 = edges + 5; 3314 edge3 = edges + 9; 3315 } 3316 3317 dist1 = edge2->opos - edge1->opos; 3318 dist2 = edge3->opos - edge2->opos; 3319 3320 span = dist1 - dist2; 3321 if ( span < 0 ) 3322 span = -span; 3323 3324 if ( span < 8 ) 3325 { 3326 delta = edge3->pos - ( 2 * edge2->pos - edge1->pos ); 3327 edge3->pos -= delta; 3328 if ( edge3->link ) 3329 edge3->link->pos -= delta; 3330 3331 /* move the serifs along with the stem */ 3332 if ( n_edges == 12 ) 3333 { 3334 ( edges + 8 )->pos -= delta; 3335 ( edges + 11 )->pos -= delta; 3336 } 3337 3338 edge3->flags |= AF_EDGE_DONE; 3339 if ( edge3->link ) 3340 edge3->link->flags |= AF_EDGE_DONE; 3341 } 3342 } 3343 3344 if ( has_serifs || !anchor ) 3345 { 3346 /* 3347 * now hint the remaining edges (serifs and single) in order 3348 * to complete our processing 3349 */ 3350 for ( edge = edges; edge < edge_limit; edge++ ) 3351 { 3352 FT_Pos delta; 3353 3354 3355 if ( edge->flags & AF_EDGE_DONE ) 3356 continue; 3357 3358 delta = 1000; 3359 3360 if ( edge->serif ) 3361 { 3362 delta = edge->serif->opos - edge->opos; 3363 if ( delta < 0 ) 3364 delta = -delta; 3365 } 3366 3367 if ( delta < 64 + 16 ) 3368 { 3369 af_latin_align_serif_edge( hints, edge->serif, edge ); 3370 FT_TRACE5(( " SERIF: edge %d (opos=%.2f) serif to %d (opos=%.2f)" 3371 " aligned to %.2f\n", 3372 edge - edges, edge->opos / 64.0, 3373 edge->serif - edges, edge->serif->opos / 64.0, 3374 edge->pos / 64.0 )); 3375 } 3376 else if ( !anchor ) 3377 { 3378 edge->pos = FT_PIX_ROUND( edge->opos ); 3379 anchor = edge; 3380 FT_TRACE5(( " SERIF_ANCHOR: edge %d (opos=%.2f)" 3381 " snapped to %.2f\n", 3382 edge-edges, edge->opos / 64.0, edge->pos / 64.0 )); 3383 } 3384 else 3385 { 3386 AF_Edge before, after; 3387 3388 3389 for ( before = edge - 1; before >= edges; before-- ) 3390 if ( before->flags & AF_EDGE_DONE ) 3391 break; 3392 3393 for ( after = edge + 1; after < edge_limit; after++ ) 3394 if ( after->flags & AF_EDGE_DONE ) 3395 break; 3396 3397 if ( before >= edges && before < edge && 3398 after < edge_limit && after > edge ) 3399 { 3400 if ( after->opos == before->opos ) 3401 edge->pos = before->pos; 3402 else 3403 edge->pos = before->pos + 3404 FT_MulDiv( edge->opos - before->opos, 3405 after->pos - before->pos, 3406 after->opos - before->opos ); 3407 3408 FT_TRACE5(( " SERIF_LINK1: edge %d (opos=%.2f) snapped to %.2f" 3409 " from %d (opos=%.2f)\n", 3410 edge - edges, edge->opos / 64.0, 3411 edge->pos / 64.0, 3412 before - edges, before->opos / 64.0 )); 3413 } 3414 else 3415 { 3416 edge->pos = anchor->pos + 3417 ( ( edge->opos - anchor->opos + 16 ) & ~31 ); 3418 FT_TRACE5(( " SERIF_LINK2: edge %d (opos=%.2f)" 3419 " snapped to %.2f\n", 3420 edge - edges, edge->opos / 64.0, edge->pos / 64.0 )); 3421 } 3422 } 3423 3424 #ifdef FT_DEBUG_LEVEL_TRACE 3425 num_actions++; 3426 #endif 3427 edge->flags |= AF_EDGE_DONE; 3428 3429 if ( edge > edges && 3430 ( top_to_bottom_hinting ? ( edge->pos > edge[-1].pos ) 3431 : ( edge->pos < edge[-1].pos ) ) ) 3432 { 3433 /* don't move if stem would (almost) disappear otherwise; */ 3434 /* the ad-hoc value 16 corresponds to 1/4px */ 3435 if ( edge->link && FT_ABS( edge->link->pos - edge[-1].pos ) > 16 ) 3436 { 3437 #ifdef FT_DEBUG_LEVEL_TRACE 3438 FT_TRACE5(( " BOUND: edge %d (pos=%.2f) moved to %.2f\n", 3439 edge - edges, 3440 edge->pos / 64.0, 3441 edge[-1].pos / 64.0 )); 3442 3443 num_actions++; 3444 #endif 3445 edge->pos = edge[-1].pos; 3446 } 3447 } 3448 3449 if ( edge + 1 < edge_limit && 3450 edge[1].flags & AF_EDGE_DONE && 3451 ( top_to_bottom_hinting ? ( edge->pos < edge[1].pos ) 3452 : ( edge->pos > edge[1].pos ) ) ) 3453 { 3454 /* don't move if stem would (almost) disappear otherwise; */ 3455 /* the ad-hoc value 16 corresponds to 1/4px */ 3456 if ( edge->link && FT_ABS( edge->link->pos - edge[-1].pos ) > 16 ) 3457 { 3458 #ifdef FT_DEBUG_LEVEL_TRACE 3459 FT_TRACE5(( " BOUND: edge %d (pos=%.2f) moved to %.2f\n", 3460 edge - edges, 3461 edge->pos / 64.0, 3462 edge[1].pos / 64.0 )); 3463 3464 num_actions++; 3465 #endif 3466 3467 edge->pos = edge[1].pos; 3468 } 3469 } 3470 } 3471 } 3472 3473 #ifdef FT_DEBUG_LEVEL_TRACE 3474 if ( !num_actions ) 3475 FT_TRACE5(( " (none)\n" )); 3476 FT_TRACE5(( "\n" )); 3477 #endif 3478 } 3479 3480 3481 /* Apply the complete hinting algorithm to a latin glyph. */ 3482 3483 static FT_Error 3484 af_latin_hints_apply( FT_UInt glyph_index, 3485 AF_GlyphHints hints, 3486 FT_Outline* outline, 3487 AF_LatinMetrics metrics ) 3488 { 3489 FT_Error error; 3490 int dim; 3491 3492 AF_LatinAxis axis; 3493 3494 3495 error = af_glyph_hints_reload( hints, outline ); 3496 if ( error ) 3497 goto Exit; 3498 3499 /* analyze glyph outline */ 3500 if ( AF_HINTS_DO_HORIZONTAL( hints ) ) 3501 { 3502 axis = &metrics->axis[AF_DIMENSION_HORZ]; 3503 error = af_latin_hints_detect_features( hints, 3504 axis->width_count, 3505 axis->widths, 3506 AF_DIMENSION_HORZ ); 3507 if ( error ) 3508 goto Exit; 3509 } 3510 3511 if ( AF_HINTS_DO_VERTICAL( hints ) ) 3512 { 3513 axis = &metrics->axis[AF_DIMENSION_VERT]; 3514 error = af_latin_hints_detect_features( hints, 3515 axis->width_count, 3516 axis->widths, 3517 AF_DIMENSION_VERT ); 3518 if ( error ) 3519 goto Exit; 3520 3521 /* apply blue zones to base characters only */ 3522 if ( !( metrics->root.globals->glyph_styles[glyph_index] & AF_NONBASE ) ) 3523 af_latin_hints_compute_blue_edges( hints, metrics ); 3524 } 3525 3526 /* grid-fit the outline */ 3527 for ( dim = 0; dim < AF_DIMENSION_MAX; dim++ ) 3528 { 3529 #ifdef AF_CONFIG_OPTION_USE_WARPER 3530 if ( dim == AF_DIMENSION_HORZ && 3531 metrics->root.scaler.render_mode == FT_RENDER_MODE_NORMAL && 3532 AF_HINTS_DO_WARP( hints ) ) 3533 { 3534 AF_WarperRec warper; 3535 FT_Fixed scale; 3536 FT_Pos delta; 3537 3538 3539 af_warper_compute( &warper, hints, (AF_Dimension)dim, 3540 &scale, &delta ); 3541 af_glyph_hints_scale_dim( hints, (AF_Dimension)dim, 3542 scale, delta ); 3543 continue; 3544 } 3545 #endif /* AF_CONFIG_OPTION_USE_WARPER */ 3546 3547 if ( ( dim == AF_DIMENSION_HORZ && AF_HINTS_DO_HORIZONTAL( hints ) ) || 3548 ( dim == AF_DIMENSION_VERT && AF_HINTS_DO_VERTICAL( hints ) ) ) 3549 { 3550 af_latin_hint_edges( hints, (AF_Dimension)dim ); 3551 af_glyph_hints_align_edge_points( hints, (AF_Dimension)dim ); 3552 af_glyph_hints_align_strong_points( hints, (AF_Dimension)dim ); 3553 af_glyph_hints_align_weak_points( hints, (AF_Dimension)dim ); 3554 } 3555 } 3556 3557 af_glyph_hints_save( hints, outline ); 3558 3559 Exit: 3560 return error; 3561 } 3562 3563 3564 /*************************************************************************/ 3565 /*************************************************************************/ 3566 /***** *****/ 3567 /***** L A T I N S C R I P T C L A S S *****/ 3568 /***** *****/ 3569 /*************************************************************************/ 3570 /*************************************************************************/ 3571 3572 3573 AF_DEFINE_WRITING_SYSTEM_CLASS( 3574 af_latin_writing_system_class, 3575 3576 AF_WRITING_SYSTEM_LATIN, 3577 3578 sizeof ( AF_LatinMetricsRec ), 3579 3580 (AF_WritingSystem_InitMetricsFunc) af_latin_metrics_init, /* style_metrics_init */ 3581 (AF_WritingSystem_ScaleMetricsFunc)af_latin_metrics_scale, /* style_metrics_scale */ 3582 (AF_WritingSystem_DoneMetricsFunc) NULL, /* style_metrics_done */ 3583 (AF_WritingSystem_GetStdWidthsFunc)af_latin_get_standard_widths, /* style_metrics_getstdw */ 3584 3585 (AF_WritingSystem_InitHintsFunc) af_latin_hints_init, /* style_hints_init */ 3586 (AF_WritingSystem_ApplyHintsFunc) af_latin_hints_apply /* style_hints_apply */ 3587 ) 3588 3589 3590 /* END */ 3591
