1 /**************************************************************************** 2 * 3 * ftstroke.c 4 * 5 * FreeType path stroker (body). 6 * 7 * Copyright (C) 2002-2019 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_STROKER_H 21 #include FT_TRIGONOMETRY_H 22 #include FT_OUTLINE_H 23 #include FT_INTERNAL_MEMORY_H 24 #include FT_INTERNAL_DEBUG_H 25 #include FT_INTERNAL_OBJECTS_H 26 27 28 /* declare an extern to access `ft_outline_glyph_class' globally */ 29 /* allocated in `ftglyph.c' */ 30 FT_CALLBACK_TABLE const FT_Glyph_Class ft_outline_glyph_class; 31 32 33 /* documentation is in ftstroke.h */ 34 35 FT_EXPORT_DEF( FT_StrokerBorder ) 36 FT_Outline_GetInsideBorder( FT_Outline* outline ) 37 { 38 FT_Orientation o = FT_Outline_Get_Orientation( outline ); 39 40 41 return o == FT_ORIENTATION_TRUETYPE ? FT_STROKER_BORDER_RIGHT 42 : FT_STROKER_BORDER_LEFT; 43 } 44 45 46 /* documentation is in ftstroke.h */ 47 48 FT_EXPORT_DEF( FT_StrokerBorder ) 49 FT_Outline_GetOutsideBorder( FT_Outline* outline ) 50 { 51 FT_Orientation o = FT_Outline_Get_Orientation( outline ); 52 53 54 return o == FT_ORIENTATION_TRUETYPE ? FT_STROKER_BORDER_LEFT 55 : FT_STROKER_BORDER_RIGHT; 56 } 57 58 59 /*************************************************************************/ 60 /*************************************************************************/ 61 /***** *****/ 62 /***** BEZIER COMPUTATIONS *****/ 63 /***** *****/ 64 /*************************************************************************/ 65 /*************************************************************************/ 66 67 #define FT_SMALL_CONIC_THRESHOLD ( FT_ANGLE_PI / 6 ) 68 #define FT_SMALL_CUBIC_THRESHOLD ( FT_ANGLE_PI / 8 ) 69 70 #define FT_EPSILON 2 71 72 #define FT_IS_SMALL( x ) ( (x) > -FT_EPSILON && (x) < FT_EPSILON ) 73 74 75 static FT_Pos 76 ft_pos_abs( FT_Pos x ) 77 { 78 return x >= 0 ? x : -x; 79 } 80 81 82 static void 83 ft_conic_split( FT_Vector* base ) 84 { 85 FT_Pos a, b; 86 87 88 base[4].x = base[2].x; 89 b = base[1].x; 90 a = base[3].x = ( base[2].x + b ) / 2; 91 b = base[1].x = ( base[0].x + b ) / 2; 92 base[2].x = ( a + b ) / 2; 93 94 base[4].y = base[2].y; 95 b = base[1].y; 96 a = base[3].y = ( base[2].y + b ) / 2; 97 b = base[1].y = ( base[0].y + b ) / 2; 98 base[2].y = ( a + b ) / 2; 99 } 100 101 102 static FT_Bool 103 ft_conic_is_small_enough( FT_Vector* base, 104 FT_Angle *angle_in, 105 FT_Angle *angle_out ) 106 { 107 FT_Vector d1, d2; 108 FT_Angle theta; 109 FT_Int close1, close2; 110 111 112 d1.x = base[1].x - base[2].x; 113 d1.y = base[1].y - base[2].y; 114 d2.x = base[0].x - base[1].x; 115 d2.y = base[0].y - base[1].y; 116 117 close1 = FT_IS_SMALL( d1.x ) && FT_IS_SMALL( d1.y ); 118 close2 = FT_IS_SMALL( d2.x ) && FT_IS_SMALL( d2.y ); 119 120 if ( close1 ) 121 { 122 if ( close2 ) 123 { 124 /* basically a point; */ 125 /* do nothing to retain original direction */ 126 } 127 else 128 { 129 *angle_in = 130 *angle_out = FT_Atan2( d2.x, d2.y ); 131 } 132 } 133 else /* !close1 */ 134 { 135 if ( close2 ) 136 { 137 *angle_in = 138 *angle_out = FT_Atan2( d1.x, d1.y ); 139 } 140 else 141 { 142 *angle_in = FT_Atan2( d1.x, d1.y ); 143 *angle_out = FT_Atan2( d2.x, d2.y ); 144 } 145 } 146 147 theta = ft_pos_abs( FT_Angle_Diff( *angle_in, *angle_out ) ); 148 149 return FT_BOOL( theta < FT_SMALL_CONIC_THRESHOLD ); 150 } 151 152 153 static void 154 ft_cubic_split( FT_Vector* base ) 155 { 156 FT_Pos a, b, c, d; 157 158 159 base[6].x = base[3].x; 160 c = base[1].x; 161 d = base[2].x; 162 base[1].x = a = ( base[0].x + c ) / 2; 163 base[5].x = b = ( base[3].x + d ) / 2; 164 c = ( c + d ) / 2; 165 base[2].x = a = ( a + c ) / 2; 166 base[4].x = b = ( b + c ) / 2; 167 base[3].x = ( a + b ) / 2; 168 169 base[6].y = base[3].y; 170 c = base[1].y; 171 d = base[2].y; 172 base[1].y = a = ( base[0].y + c ) / 2; 173 base[5].y = b = ( base[3].y + d ) / 2; 174 c = ( c + d ) / 2; 175 base[2].y = a = ( a + c ) / 2; 176 base[4].y = b = ( b + c ) / 2; 177 base[3].y = ( a + b ) / 2; 178 } 179 180 181 /* Return the average of `angle1' and `angle2'. */ 182 /* This gives correct result even if `angle1' and `angle2' */ 183 /* have opposite signs. */ 184 static FT_Angle 185 ft_angle_mean( FT_Angle angle1, 186 FT_Angle angle2 ) 187 { 188 return angle1 + FT_Angle_Diff( angle1, angle2 ) / 2; 189 } 190 191 192 static FT_Bool 193 ft_cubic_is_small_enough( FT_Vector* base, 194 FT_Angle *angle_in, 195 FT_Angle *angle_mid, 196 FT_Angle *angle_out ) 197 { 198 FT_Vector d1, d2, d3; 199 FT_Angle theta1, theta2; 200 FT_Int close1, close2, close3; 201 202 203 d1.x = base[2].x - base[3].x; 204 d1.y = base[2].y - base[3].y; 205 d2.x = base[1].x - base[2].x; 206 d2.y = base[1].y - base[2].y; 207 d3.x = base[0].x - base[1].x; 208 d3.y = base[0].y - base[1].y; 209 210 close1 = FT_IS_SMALL( d1.x ) && FT_IS_SMALL( d1.y ); 211 close2 = FT_IS_SMALL( d2.x ) && FT_IS_SMALL( d2.y ); 212 close3 = FT_IS_SMALL( d3.x ) && FT_IS_SMALL( d3.y ); 213 214 if ( close1 ) 215 { 216 if ( close2 ) 217 { 218 if ( close3 ) 219 { 220 /* basically a point; */ 221 /* do nothing to retain original direction */ 222 } 223 else /* !close3 */ 224 { 225 *angle_in = 226 *angle_mid = 227 *angle_out = FT_Atan2( d3.x, d3.y ); 228 } 229 } 230 else /* !close2 */ 231 { 232 if ( close3 ) 233 { 234 *angle_in = 235 *angle_mid = 236 *angle_out = FT_Atan2( d2.x, d2.y ); 237 } 238 else /* !close3 */ 239 { 240 *angle_in = 241 *angle_mid = FT_Atan2( d2.x, d2.y ); 242 *angle_out = FT_Atan2( d3.x, d3.y ); 243 } 244 } 245 } 246 else /* !close1 */ 247 { 248 if ( close2 ) 249 { 250 if ( close3 ) 251 { 252 *angle_in = 253 *angle_mid = 254 *angle_out = FT_Atan2( d1.x, d1.y ); 255 } 256 else /* !close3 */ 257 { 258 *angle_in = FT_Atan2( d1.x, d1.y ); 259 *angle_out = FT_Atan2( d3.x, d3.y ); 260 *angle_mid = ft_angle_mean( *angle_in, *angle_out ); 261 } 262 } 263 else /* !close2 */ 264 { 265 if ( close3 ) 266 { 267 *angle_in = FT_Atan2( d1.x, d1.y ); 268 *angle_mid = 269 *angle_out = FT_Atan2( d2.x, d2.y ); 270 } 271 else /* !close3 */ 272 { 273 *angle_in = FT_Atan2( d1.x, d1.y ); 274 *angle_mid = FT_Atan2( d2.x, d2.y ); 275 *angle_out = FT_Atan2( d3.x, d3.y ); 276 } 277 } 278 } 279 280 theta1 = ft_pos_abs( FT_Angle_Diff( *angle_in, *angle_mid ) ); 281 theta2 = ft_pos_abs( FT_Angle_Diff( *angle_mid, *angle_out ) ); 282 283 return FT_BOOL( theta1 < FT_SMALL_CUBIC_THRESHOLD && 284 theta2 < FT_SMALL_CUBIC_THRESHOLD ); 285 } 286 287 288 /*************************************************************************/ 289 /*************************************************************************/ 290 /***** *****/ 291 /***** STROKE BORDERS *****/ 292 /***** *****/ 293 /*************************************************************************/ 294 /*************************************************************************/ 295 296 typedef enum FT_StrokeTags_ 297 { 298 FT_STROKE_TAG_ON = 1, /* on-curve point */ 299 FT_STROKE_TAG_CUBIC = 2, /* cubic off-point */ 300 FT_STROKE_TAG_BEGIN = 4, /* sub-path start */ 301 FT_STROKE_TAG_END = 8 /* sub-path end */ 302 303 } FT_StrokeTags; 304 305 #define FT_STROKE_TAG_BEGIN_END ( FT_STROKE_TAG_BEGIN | FT_STROKE_TAG_END ) 306 307 typedef struct FT_StrokeBorderRec_ 308 { 309 FT_UInt num_points; 310 FT_UInt max_points; 311 FT_Vector* points; 312 FT_Byte* tags; 313 FT_Bool movable; /* TRUE for ends of lineto borders */ 314 FT_Int start; /* index of current sub-path start point */ 315 FT_Memory memory; 316 FT_Bool valid; 317 318 } FT_StrokeBorderRec, *FT_StrokeBorder; 319 320 321 static FT_Error 322 ft_stroke_border_grow( FT_StrokeBorder border, 323 FT_UInt new_points ) 324 { 325 FT_UInt old_max = border->max_points; 326 FT_UInt new_max = border->num_points + new_points; 327 FT_Error error = FT_Err_Ok; 328 329 330 if ( new_max > old_max ) 331 { 332 FT_UInt cur_max = old_max; 333 FT_Memory memory = border->memory; 334 335 336 while ( cur_max < new_max ) 337 cur_max += ( cur_max >> 1 ) + 16; 338 339 if ( FT_RENEW_ARRAY( border->points, old_max, cur_max ) || 340 FT_RENEW_ARRAY( border->tags, old_max, cur_max ) ) 341 goto Exit; 342 343 border->max_points = cur_max; 344 } 345 346 Exit: 347 return error; 348 } 349 350 351 static void 352 ft_stroke_border_close( FT_StrokeBorder border, 353 FT_Bool reverse ) 354 { 355 FT_UInt start = (FT_UInt)border->start; 356 FT_UInt count = border->num_points; 357 358 359 FT_ASSERT( border->start >= 0 ); 360 361 /* don't record empty paths! */ 362 if ( count <= start + 1U ) 363 border->num_points = start; 364 else 365 { 366 /* copy the last point to the start of this sub-path, since */ 367 /* it contains the `adjusted' starting coordinates */ 368 border->num_points = --count; 369 border->points[start] = border->points[count]; 370 border->tags[start] = border->tags[count]; 371 372 if ( reverse ) 373 { 374 /* reverse the points */ 375 { 376 FT_Vector* vec1 = border->points + start + 1; 377 FT_Vector* vec2 = border->points + count - 1; 378 379 380 for ( ; vec1 < vec2; vec1++, vec2-- ) 381 { 382 FT_Vector tmp; 383 384 385 tmp = *vec1; 386 *vec1 = *vec2; 387 *vec2 = tmp; 388 } 389 } 390 391 /* then the tags */ 392 { 393 FT_Byte* tag1 = border->tags + start + 1; 394 FT_Byte* tag2 = border->tags + count - 1; 395 396 397 for ( ; tag1 < tag2; tag1++, tag2-- ) 398 { 399 FT_Byte tmp; 400 401 402 tmp = *tag1; 403 *tag1 = *tag2; 404 *tag2 = tmp; 405 } 406 } 407 } 408 409 border->tags[start ] |= FT_STROKE_TAG_BEGIN; 410 border->tags[count - 1] |= FT_STROKE_TAG_END; 411 } 412 413 border->start = -1; 414 border->movable = FALSE; 415 } 416 417 418 static FT_Error 419 ft_stroke_border_lineto( FT_StrokeBorder border, 420 FT_Vector* to, 421 FT_Bool movable ) 422 { 423 FT_Error error = FT_Err_Ok; 424 425 426 FT_ASSERT( border->start >= 0 ); 427 428 if ( border->movable ) 429 { 430 /* move last point */ 431 border->points[border->num_points - 1] = *to; 432 } 433 else 434 { 435 /* don't add zero-length lineto, but always add moveto */ 436 if ( border->num_points > (FT_UInt)border->start && 437 FT_IS_SMALL( border->points[border->num_points - 1].x - to->x ) && 438 FT_IS_SMALL( border->points[border->num_points - 1].y - to->y ) ) 439 return error; 440 441 /* add one point */ 442 error = ft_stroke_border_grow( border, 1 ); 443 if ( !error ) 444 { 445 FT_Vector* vec = border->points + border->num_points; 446 FT_Byte* tag = border->tags + border->num_points; 447 448 449 vec[0] = *to; 450 tag[0] = FT_STROKE_TAG_ON; 451 452 border->num_points += 1; 453 } 454 } 455 border->movable = movable; 456 return error; 457 } 458 459 460 static FT_Error 461 ft_stroke_border_conicto( FT_StrokeBorder border, 462 FT_Vector* control, 463 FT_Vector* to ) 464 { 465 FT_Error error; 466 467 468 FT_ASSERT( border->start >= 0 ); 469 470 error = ft_stroke_border_grow( border, 2 ); 471 if ( !error ) 472 { 473 FT_Vector* vec = border->points + border->num_points; 474 FT_Byte* tag = border->tags + border->num_points; 475 476 477 vec[0] = *control; 478 vec[1] = *to; 479 480 tag[0] = 0; 481 tag[1] = FT_STROKE_TAG_ON; 482 483 border->num_points += 2; 484 } 485 486 border->movable = FALSE; 487 488 return error; 489 } 490 491 492 static FT_Error 493 ft_stroke_border_cubicto( FT_StrokeBorder border, 494 FT_Vector* control1, 495 FT_Vector* control2, 496 FT_Vector* to ) 497 { 498 FT_Error error; 499 500 501 FT_ASSERT( border->start >= 0 ); 502 503 error = ft_stroke_border_grow( border, 3 ); 504 if ( !error ) 505 { 506 FT_Vector* vec = border->points + border->num_points; 507 FT_Byte* tag = border->tags + border->num_points; 508 509 510 vec[0] = *control1; 511 vec[1] = *control2; 512 vec[2] = *to; 513 514 tag[0] = FT_STROKE_TAG_CUBIC; 515 tag[1] = FT_STROKE_TAG_CUBIC; 516 tag[2] = FT_STROKE_TAG_ON; 517 518 border->num_points += 3; 519 } 520 521 border->movable = FALSE; 522 523 return error; 524 } 525 526 527 #define FT_ARC_CUBIC_ANGLE ( FT_ANGLE_PI / 2 ) 528 529 530 static FT_Error 531 ft_stroke_border_arcto( FT_StrokeBorder border, 532 FT_Vector* center, 533 FT_Fixed radius, 534 FT_Angle angle_start, 535 FT_Angle angle_diff ) 536 { 537 FT_Angle total, angle, step, rotate, next, theta; 538 FT_Vector a, b, a2, b2; 539 FT_Fixed length; 540 FT_Error error = FT_Err_Ok; 541 542 543 /* compute start point */ 544 FT_Vector_From_Polar( &a, radius, angle_start ); 545 a.x += center->x; 546 a.y += center->y; 547 548 total = angle_diff; 549 angle = angle_start; 550 rotate = ( angle_diff >= 0 ) ? FT_ANGLE_PI2 : -FT_ANGLE_PI2; 551 552 while ( total != 0 ) 553 { 554 step = total; 555 if ( step > FT_ARC_CUBIC_ANGLE ) 556 step = FT_ARC_CUBIC_ANGLE; 557 558 else if ( step < -FT_ARC_CUBIC_ANGLE ) 559 step = -FT_ARC_CUBIC_ANGLE; 560 561 next = angle + step; 562 theta = step; 563 if ( theta < 0 ) 564 theta = -theta; 565 566 theta >>= 1; 567 568 /* compute end point */ 569 FT_Vector_From_Polar( &b, radius, next ); 570 b.x += center->x; 571 b.y += center->y; 572 573 /* compute first and second control points */ 574 length = FT_MulDiv( radius, FT_Sin( theta ) * 4, 575 ( 0x10000L + FT_Cos( theta ) ) * 3 ); 576 577 FT_Vector_From_Polar( &a2, length, angle + rotate ); 578 a2.x += a.x; 579 a2.y += a.y; 580 581 FT_Vector_From_Polar( &b2, length, next - rotate ); 582 b2.x += b.x; 583 b2.y += b.y; 584 585 /* add cubic arc */ 586 error = ft_stroke_border_cubicto( border, &a2, &b2, &b ); 587 if ( error ) 588 break; 589 590 /* process the rest of the arc ?? */ 591 a = b; 592 total -= step; 593 angle = next; 594 } 595 596 return error; 597 } 598 599 600 static FT_Error 601 ft_stroke_border_moveto( FT_StrokeBorder border, 602 FT_Vector* to ) 603 { 604 /* close current open path if any ? */ 605 if ( border->start >= 0 ) 606 ft_stroke_border_close( border, FALSE ); 607 608 border->start = (FT_Int)border->num_points; 609 border->movable = FALSE; 610 611 return ft_stroke_border_lineto( border, to, FALSE ); 612 } 613 614 615 static void 616 ft_stroke_border_init( FT_StrokeBorder border, 617 FT_Memory memory ) 618 { 619 border->memory = memory; 620 border->points = NULL; 621 border->tags = NULL; 622 623 border->num_points = 0; 624 border->max_points = 0; 625 border->start = -1; 626 border->valid = FALSE; 627 } 628 629 630 static void 631 ft_stroke_border_reset( FT_StrokeBorder border ) 632 { 633 border->num_points = 0; 634 border->start = -1; 635 border->valid = FALSE; 636 } 637 638 639 static void 640 ft_stroke_border_done( FT_StrokeBorder border ) 641 { 642 FT_Memory memory = border->memory; 643 644 645 FT_FREE( border->points ); 646 FT_FREE( border->tags ); 647 648 border->num_points = 0; 649 border->max_points = 0; 650 border->start = -1; 651 border->valid = FALSE; 652 } 653 654 655 static FT_Error 656 ft_stroke_border_get_counts( FT_StrokeBorder border, 657 FT_UInt *anum_points, 658 FT_UInt *anum_contours ) 659 { 660 FT_Error error = FT_Err_Ok; 661 FT_UInt num_points = 0; 662 FT_UInt num_contours = 0; 663 664 FT_UInt count = border->num_points; 665 FT_Vector* point = border->points; 666 FT_Byte* tags = border->tags; 667 FT_Int in_contour = 0; 668 669 670 for ( ; count > 0; count--, num_points++, point++, tags++ ) 671 { 672 if ( tags[0] & FT_STROKE_TAG_BEGIN ) 673 { 674 if ( in_contour != 0 ) 675 goto Fail; 676 677 in_contour = 1; 678 } 679 else if ( in_contour == 0 ) 680 goto Fail; 681 682 if ( tags[0] & FT_STROKE_TAG_END ) 683 { 684 in_contour = 0; 685 num_contours++; 686 } 687 } 688 689 if ( in_contour != 0 ) 690 goto Fail; 691 692 border->valid = TRUE; 693 694 Exit: 695 *anum_points = num_points; 696 *anum_contours = num_contours; 697 return error; 698 699 Fail: 700 num_points = 0; 701 num_contours = 0; 702 goto Exit; 703 } 704 705 706 static void 707 ft_stroke_border_export( FT_StrokeBorder border, 708 FT_Outline* outline ) 709 { 710 /* copy point locations */ 711 if ( border->num_points ) 712 FT_ARRAY_COPY( outline->points + outline->n_points, 713 border->points, 714 border->num_points ); 715 716 /* copy tags */ 717 { 718 FT_UInt count = border->num_points; 719 FT_Byte* read = border->tags; 720 FT_Byte* write = (FT_Byte*)outline->tags + outline->n_points; 721 722 723 for ( ; count > 0; count--, read++, write++ ) 724 { 725 if ( *read & FT_STROKE_TAG_ON ) 726 *write = FT_CURVE_TAG_ON; 727 else if ( *read & FT_STROKE_TAG_CUBIC ) 728 *write = FT_CURVE_TAG_CUBIC; 729 else 730 *write = FT_CURVE_TAG_CONIC; 731 } 732 } 733 734 /* copy contours */ 735 { 736 FT_UInt count = border->num_points; 737 FT_Byte* tags = border->tags; 738 FT_Short* write = outline->contours + outline->n_contours; 739 FT_Short idx = (FT_Short)outline->n_points; 740 741 742 for ( ; count > 0; count--, tags++, idx++ ) 743 { 744 if ( *tags & FT_STROKE_TAG_END ) 745 { 746 *write++ = idx; 747 outline->n_contours++; 748 } 749 } 750 } 751 752 outline->n_points += (short)border->num_points; 753 754 FT_ASSERT( FT_Outline_Check( outline ) == 0 ); 755 } 756 757 758 /*************************************************************************/ 759 /*************************************************************************/ 760 /***** *****/ 761 /***** STROKER *****/ 762 /***** *****/ 763 /*************************************************************************/ 764 /*************************************************************************/ 765 766 #define FT_SIDE_TO_ROTATE( s ) ( FT_ANGLE_PI2 - (s) * FT_ANGLE_PI ) 767 768 typedef struct FT_StrokerRec_ 769 { 770 FT_Angle angle_in; /* direction into curr join */ 771 FT_Angle angle_out; /* direction out of join */ 772 FT_Vector center; /* current position */ 773 FT_Fixed line_length; /* length of last lineto */ 774 FT_Bool first_point; /* is this the start? */ 775 FT_Bool subpath_open; /* is the subpath open? */ 776 FT_Angle subpath_angle; /* subpath start direction */ 777 FT_Vector subpath_start; /* subpath start position */ 778 FT_Fixed subpath_line_length; /* subpath start lineto len */ 779 FT_Bool handle_wide_strokes; /* use wide strokes logic? */ 780 781 FT_Stroker_LineCap line_cap; 782 FT_Stroker_LineJoin line_join; 783 FT_Stroker_LineJoin line_join_saved; 784 FT_Fixed miter_limit; 785 FT_Fixed radius; 786 787 FT_StrokeBorderRec borders[2]; 788 FT_Library library; 789 790 } FT_StrokerRec; 791 792 793 /* documentation is in ftstroke.h */ 794 795 FT_EXPORT_DEF( FT_Error ) 796 FT_Stroker_New( FT_Library library, 797 FT_Stroker *astroker ) 798 { 799 FT_Error error; /* assigned in FT_NEW */ 800 FT_Memory memory; 801 FT_Stroker stroker = NULL; 802 803 804 if ( !library ) 805 return FT_THROW( Invalid_Library_Handle ); 806 807 if ( !astroker ) 808 return FT_THROW( Invalid_Argument ); 809 810 memory = library->memory; 811 812 if ( !FT_NEW( stroker ) ) 813 { 814 stroker->library = library; 815 816 ft_stroke_border_init( &stroker->borders[0], memory ); 817 ft_stroke_border_init( &stroker->borders[1], memory ); 818 } 819 820 *astroker = stroker; 821 822 return error; 823 } 824 825 826 /* documentation is in ftstroke.h */ 827 828 FT_EXPORT_DEF( void ) 829 FT_Stroker_Set( FT_Stroker stroker, 830 FT_Fixed radius, 831 FT_Stroker_LineCap line_cap, 832 FT_Stroker_LineJoin line_join, 833 FT_Fixed miter_limit ) 834 { 835 if ( !stroker ) 836 return; 837 838 stroker->radius = radius; 839 stroker->line_cap = line_cap; 840 stroker->line_join = line_join; 841 stroker->miter_limit = miter_limit; 842 843 /* ensure miter limit has sensible value */ 844 if ( stroker->miter_limit < 0x10000L ) 845 stroker->miter_limit = 0x10000L; 846 847 /* save line join style: */ 848 /* line join style can be temporarily changed when stroking curves */ 849 stroker->line_join_saved = line_join; 850 851 FT_Stroker_Rewind( stroker ); 852 } 853 854 855 /* documentation is in ftstroke.h */ 856 857 FT_EXPORT_DEF( void ) 858 FT_Stroker_Rewind( FT_Stroker stroker ) 859 { 860 if ( stroker ) 861 { 862 ft_stroke_border_reset( &stroker->borders[0] ); 863 ft_stroke_border_reset( &stroker->borders[1] ); 864 } 865 } 866 867 868 /* documentation is in ftstroke.h */ 869 870 FT_EXPORT_DEF( void ) 871 FT_Stroker_Done( FT_Stroker stroker ) 872 { 873 if ( stroker ) 874 { 875 FT_Memory memory = stroker->library->memory; 876 877 878 ft_stroke_border_done( &stroker->borders[0] ); 879 ft_stroke_border_done( &stroker->borders[1] ); 880 881 stroker->library = NULL; 882 FT_FREE( stroker ); 883 } 884 } 885 886 887 /* create a circular arc at a corner or cap */ 888 static FT_Error 889 ft_stroker_arcto( FT_Stroker stroker, 890 FT_Int side ) 891 { 892 FT_Angle total, rotate; 893 FT_Fixed radius = stroker->radius; 894 FT_Error error = FT_Err_Ok; 895 FT_StrokeBorder border = stroker->borders + side; 896 897 898 rotate = FT_SIDE_TO_ROTATE( side ); 899 900 total = FT_Angle_Diff( stroker->angle_in, stroker->angle_out ); 901 if ( total == FT_ANGLE_PI ) 902 total = -rotate * 2; 903 904 error = ft_stroke_border_arcto( border, 905 &stroker->center, 906 radius, 907 stroker->angle_in + rotate, 908 total ); 909 border->movable = FALSE; 910 return error; 911 } 912 913 914 /* add a cap at the end of an opened path */ 915 static FT_Error 916 ft_stroker_cap( FT_Stroker stroker, 917 FT_Angle angle, 918 FT_Int side ) 919 { 920 FT_Error error = FT_Err_Ok; 921 922 923 if ( stroker->line_cap == FT_STROKER_LINECAP_ROUND ) 924 { 925 /* add a round cap */ 926 stroker->angle_in = angle; 927 stroker->angle_out = angle + FT_ANGLE_PI; 928 929 error = ft_stroker_arcto( stroker, side ); 930 } 931 else if ( stroker->line_cap == FT_STROKER_LINECAP_SQUARE ) 932 { 933 /* add a square cap */ 934 FT_Vector delta, delta2; 935 FT_Angle rotate = FT_SIDE_TO_ROTATE( side ); 936 FT_Fixed radius = stroker->radius; 937 FT_StrokeBorder border = stroker->borders + side; 938 939 940 FT_Vector_From_Polar( &delta2, radius, angle + rotate ); 941 FT_Vector_From_Polar( &delta, radius, angle ); 942 943 delta.x += stroker->center.x + delta2.x; 944 delta.y += stroker->center.y + delta2.y; 945 946 error = ft_stroke_border_lineto( border, &delta, FALSE ); 947 if ( error ) 948 goto Exit; 949 950 FT_Vector_From_Polar( &delta2, radius, angle - rotate ); 951 FT_Vector_From_Polar( &delta, radius, angle ); 952 953 delta.x += delta2.x + stroker->center.x; 954 delta.y += delta2.y + stroker->center.y; 955 956 error = ft_stroke_border_lineto( border, &delta, FALSE ); 957 } 958 else if ( stroker->line_cap == FT_STROKER_LINECAP_BUTT ) 959 { 960 /* add a butt ending */ 961 FT_Vector delta; 962 FT_Angle rotate = FT_SIDE_TO_ROTATE( side ); 963 FT_Fixed radius = stroker->radius; 964 FT_StrokeBorder border = stroker->borders + side; 965 966 967 FT_Vector_From_Polar( &delta, radius, angle + rotate ); 968 969 delta.x += stroker->center.x; 970 delta.y += stroker->center.y; 971 972 error = ft_stroke_border_lineto( border, &delta, FALSE ); 973 if ( error ) 974 goto Exit; 975 976 FT_Vector_From_Polar( &delta, radius, angle - rotate ); 977 978 delta.x += stroker->center.x; 979 delta.y += stroker->center.y; 980 981 error = ft_stroke_border_lineto( border, &delta, FALSE ); 982 } 983 984 Exit: 985 return error; 986 } 987 988 989 /* process an inside corner, i.e. compute intersection */ 990 static FT_Error 991 ft_stroker_inside( FT_Stroker stroker, 992 FT_Int side, 993 FT_Fixed line_length ) 994 { 995 FT_StrokeBorder border = stroker->borders + side; 996 FT_Angle phi, theta, rotate; 997 FT_Fixed length, thcos; 998 FT_Vector delta; 999 FT_Error error = FT_Err_Ok; 1000 FT_Bool intersect; /* use intersection of lines? */ 1001 1002 1003 rotate = FT_SIDE_TO_ROTATE( side ); 1004 1005 theta = FT_Angle_Diff( stroker->angle_in, stroker->angle_out ) / 2; 1006 1007 /* Only intersect borders if between two lineto's and both */ 1008 /* lines are long enough (line_length is zero for curves). */ 1009 /* Also avoid U-turns of nearly 180 degree. */ 1010 if ( !border->movable || line_length == 0 || 1011 theta > 0x59C000 || theta < -0x59C000 ) 1012 intersect = FALSE; 1013 else 1014 { 1015 /* compute minimum required length of lines */ 1016 FT_Fixed min_length = ft_pos_abs( FT_MulFix( stroker->radius, 1017 FT_Tan( theta ) ) ); 1018 1019 1020 intersect = FT_BOOL( min_length && 1021 stroker->line_length >= min_length && 1022 line_length >= min_length ); 1023 } 1024 1025 if ( !intersect ) 1026 { 1027 FT_Vector_From_Polar( &delta, stroker->radius, 1028 stroker->angle_out + rotate ); 1029 delta.x += stroker->center.x; 1030 delta.y += stroker->center.y; 1031 1032 border->movable = FALSE; 1033 } 1034 else 1035 { 1036 /* compute median angle */ 1037 phi = stroker->angle_in + theta; 1038 1039 thcos = FT_Cos( theta ); 1040 1041 length = FT_DivFix( stroker->radius, thcos ); 1042 1043 FT_Vector_From_Polar( &delta, length, phi + rotate ); 1044 delta.x += stroker->center.x; 1045 delta.y += stroker->center.y; 1046 } 1047 1048 error = ft_stroke_border_lineto( border, &delta, FALSE ); 1049 1050 return error; 1051 } 1052 1053 1054 /* process an outside corner, i.e. compute bevel/miter/round */ 1055 static FT_Error 1056 ft_stroker_outside( FT_Stroker stroker, 1057 FT_Int side, 1058 FT_Fixed line_length ) 1059 { 1060 FT_StrokeBorder border = stroker->borders + side; 1061 FT_Error error; 1062 FT_Angle rotate; 1063 1064 1065 if ( stroker->line_join == FT_STROKER_LINEJOIN_ROUND ) 1066 error = ft_stroker_arcto( stroker, side ); 1067 else 1068 { 1069 /* this is a mitered (pointed) or beveled (truncated) corner */ 1070 FT_Fixed sigma = 0, radius = stroker->radius; 1071 FT_Angle theta = 0, phi = 0; 1072 FT_Fixed thcos = 0; 1073 FT_Bool bevel, fixed_bevel; 1074 1075 1076 rotate = FT_SIDE_TO_ROTATE( side ); 1077 1078 bevel = 1079 FT_BOOL( stroker->line_join == FT_STROKER_LINEJOIN_BEVEL ); 1080 1081 fixed_bevel = 1082 FT_BOOL( stroker->line_join != FT_STROKER_LINEJOIN_MITER_VARIABLE ); 1083 1084 if ( !bevel ) 1085 { 1086 theta = FT_Angle_Diff( stroker->angle_in, stroker->angle_out ); 1087 1088 if ( theta == FT_ANGLE_PI ) 1089 { 1090 theta = rotate; 1091 phi = stroker->angle_in; 1092 } 1093 else 1094 { 1095 theta /= 2; 1096 phi = stroker->angle_in + theta + rotate; 1097 } 1098 1099 thcos = FT_Cos( theta ); 1100 sigma = FT_MulFix( stroker->miter_limit, thcos ); 1101 1102 /* is miter limit exceeded? */ 1103 if ( sigma < 0x10000L ) 1104 { 1105 /* don't create variable bevels for very small deviations; */ 1106 /* FT_Sin(x) = 0 for x <= 57 */ 1107 if ( fixed_bevel || ft_pos_abs( theta ) > 57 ) 1108 bevel = TRUE; 1109 } 1110 } 1111 1112 if ( bevel ) /* this is a bevel (broken angle) */ 1113 { 1114 if ( fixed_bevel ) 1115 { 1116 /* the outer corners are simply joined together */ 1117 FT_Vector delta; 1118 1119 1120 /* add bevel */ 1121 FT_Vector_From_Polar( &delta, 1122 radius, 1123 stroker->angle_out + rotate ); 1124 delta.x += stroker->center.x; 1125 delta.y += stroker->center.y; 1126 1127 border->movable = FALSE; 1128 error = ft_stroke_border_lineto( border, &delta, FALSE ); 1129 } 1130 else /* variable bevel */ 1131 { 1132 /* the miter is truncated */ 1133 FT_Vector middle, delta; 1134 FT_Fixed length; 1135 1136 1137 /* compute middle point */ 1138 FT_Vector_From_Polar( &middle, 1139 FT_MulFix( radius, stroker->miter_limit ), 1140 phi ); 1141 middle.x += stroker->center.x; 1142 middle.y += stroker->center.y; 1143 1144 /* compute first angle point */ 1145 length = FT_MulDiv( radius, 0x10000L - sigma, 1146 ft_pos_abs( FT_Sin( theta ) ) ); 1147 1148 FT_Vector_From_Polar( &delta, length, phi + rotate ); 1149 delta.x += middle.x; 1150 delta.y += middle.y; 1151 1152 error = ft_stroke_border_lineto( border, &delta, FALSE ); 1153 if ( error ) 1154 goto Exit; 1155 1156 /* compute second angle point */ 1157 FT_Vector_From_Polar( &delta, length, phi - rotate ); 1158 delta.x += middle.x; 1159 delta.y += middle.y; 1160 1161 error = ft_stroke_border_lineto( border, &delta, FALSE ); 1162 if ( error ) 1163 goto Exit; 1164 1165 /* finally, add an end point; only needed if not lineto */ 1166 /* (line_length is zero for curves) */ 1167 if ( line_length == 0 ) 1168 { 1169 FT_Vector_From_Polar( &delta, 1170 radius, 1171 stroker->angle_out + rotate ); 1172 1173 delta.x += stroker->center.x; 1174 delta.y += stroker->center.y; 1175 1176 error = ft_stroke_border_lineto( border, &delta, FALSE ); 1177 } 1178 } 1179 } 1180 else /* this is a miter (intersection) */ 1181 { 1182 FT_Fixed length; 1183 FT_Vector delta; 1184 1185 1186 length = FT_DivFix( stroker->radius, thcos ); 1187 1188 FT_Vector_From_Polar( &delta, length, phi ); 1189 delta.x += stroker->center.x; 1190 delta.y += stroker->center.y; 1191 1192 error = ft_stroke_border_lineto( border, &delta, FALSE ); 1193 if ( error ) 1194 goto Exit; 1195 1196 /* now add an end point; only needed if not lineto */ 1197 /* (line_length is zero for curves) */ 1198 if ( line_length == 0 ) 1199 { 1200 FT_Vector_From_Polar( &delta, 1201 stroker->radius, 1202 stroker->angle_out + rotate ); 1203 delta.x += stroker->center.x; 1204 delta.y += stroker->center.y; 1205 1206 error = ft_stroke_border_lineto( border, &delta, FALSE ); 1207 } 1208 } 1209 } 1210 1211 Exit: 1212 return error; 1213 } 1214 1215 1216 static FT_Error 1217 ft_stroker_process_corner( FT_Stroker stroker, 1218 FT_Fixed line_length ) 1219 { 1220 FT_Error error = FT_Err_Ok; 1221 FT_Angle turn; 1222 FT_Int inside_side; 1223 1224 1225 turn = FT_Angle_Diff( stroker->angle_in, stroker->angle_out ); 1226 1227 /* no specific corner processing is required if the turn is 0 */ 1228 if ( turn == 0 ) 1229 goto Exit; 1230 1231 /* when we turn to the right, the inside side is 0 */ 1232 /* otherwise, the inside side is 1 */ 1233 inside_side = ( turn < 0 ); 1234 1235 /* process the inside side */ 1236 error = ft_stroker_inside( stroker, inside_side, line_length ); 1237 if ( error ) 1238 goto Exit; 1239 1240 /* process the outside side */ 1241 error = ft_stroker_outside( stroker, !inside_side, line_length ); 1242 1243 Exit: 1244 return error; 1245 } 1246 1247 1248 /* add two points to the left and right borders corresponding to the */ 1249 /* start of the subpath */ 1250 static FT_Error 1251 ft_stroker_subpath_start( FT_Stroker stroker, 1252 FT_Angle start_angle, 1253 FT_Fixed line_length ) 1254 { 1255 FT_Vector delta; 1256 FT_Vector point; 1257 FT_Error error; 1258 FT_StrokeBorder border; 1259 1260 1261 FT_Vector_From_Polar( &delta, stroker->radius, 1262 start_angle + FT_ANGLE_PI2 ); 1263 1264 point.x = stroker->center.x + delta.x; 1265 point.y = stroker->center.y + delta.y; 1266 1267 border = stroker->borders; 1268 error = ft_stroke_border_moveto( border, &point ); 1269 if ( error ) 1270 goto Exit; 1271 1272 point.x = stroker->center.x - delta.x; 1273 point.y = stroker->center.y - delta.y; 1274 1275 border++; 1276 error = ft_stroke_border_moveto( border, &point ); 1277 1278 /* save angle, position, and line length for last join */ 1279 /* (line_length is zero for curves) */ 1280 stroker->subpath_angle = start_angle; 1281 stroker->first_point = FALSE; 1282 stroker->subpath_line_length = line_length; 1283 1284 Exit: 1285 return error; 1286 } 1287 1288 1289 /* documentation is in ftstroke.h */ 1290 1291 FT_EXPORT_DEF( FT_Error ) 1292 FT_Stroker_LineTo( FT_Stroker stroker, 1293 FT_Vector* to ) 1294 { 1295 FT_Error error = FT_Err_Ok; 1296 FT_StrokeBorder border; 1297 FT_Vector delta; 1298 FT_Angle angle; 1299 FT_Int side; 1300 FT_Fixed line_length; 1301 1302 1303 if ( !stroker || !to ) 1304 return FT_THROW( Invalid_Argument ); 1305 1306 delta.x = to->x - stroker->center.x; 1307 delta.y = to->y - stroker->center.y; 1308 1309 /* a zero-length lineto is a no-op; avoid creating a spurious corner */ 1310 if ( delta.x == 0 && delta.y == 0 ) 1311 goto Exit; 1312 1313 /* compute length of line */ 1314 line_length = FT_Vector_Length( &delta ); 1315 1316 angle = FT_Atan2( delta.x, delta.y ); 1317 FT_Vector_From_Polar( &delta, stroker->radius, angle + FT_ANGLE_PI2 ); 1318 1319 /* process corner if necessary */ 1320 if ( stroker->first_point ) 1321 { 1322 /* This is the first segment of a subpath. We need to */ 1323 /* add a point to each border at their respective starting */ 1324 /* point locations. */ 1325 error = ft_stroker_subpath_start( stroker, angle, line_length ); 1326 if ( error ) 1327 goto Exit; 1328 } 1329 else 1330 { 1331 /* process the current corner */ 1332 stroker->angle_out = angle; 1333 error = ft_stroker_process_corner( stroker, line_length ); 1334 if ( error ) 1335 goto Exit; 1336 } 1337 1338 /* now add a line segment to both the `inside' and `outside' paths */ 1339 for ( border = stroker->borders, side = 1; side >= 0; side--, border++ ) 1340 { 1341 FT_Vector point; 1342 1343 1344 point.x = to->x + delta.x; 1345 point.y = to->y + delta.y; 1346 1347 /* the ends of lineto borders are movable */ 1348 error = ft_stroke_border_lineto( border, &point, TRUE ); 1349 if ( error ) 1350 goto Exit; 1351 1352 delta.x = -delta.x; 1353 delta.y = -delta.y; 1354 } 1355 1356 stroker->angle_in = angle; 1357 stroker->center = *to; 1358 stroker->line_length = line_length; 1359 1360 Exit: 1361 return error; 1362 } 1363 1364 1365 /* documentation is in ftstroke.h */ 1366 1367 FT_EXPORT_DEF( FT_Error ) 1368 FT_Stroker_ConicTo( FT_Stroker stroker, 1369 FT_Vector* control, 1370 FT_Vector* to ) 1371 { 1372 FT_Error error = FT_Err_Ok; 1373 FT_Vector bez_stack[34]; 1374 FT_Vector* arc; 1375 FT_Vector* limit = bez_stack + 30; 1376 FT_Bool first_arc = TRUE; 1377 1378 1379 if ( !stroker || !control || !to ) 1380 { 1381 error = FT_THROW( Invalid_Argument ); 1382 goto Exit; 1383 } 1384 1385 /* if all control points are coincident, this is a no-op; */ 1386 /* avoid creating a spurious corner */ 1387 if ( FT_IS_SMALL( stroker->center.x - control->x ) && 1388 FT_IS_SMALL( stroker->center.y - control->y ) && 1389 FT_IS_SMALL( control->x - to->x ) && 1390 FT_IS_SMALL( control->y - to->y ) ) 1391 { 1392 stroker->center = *to; 1393 goto Exit; 1394 } 1395 1396 arc = bez_stack; 1397 arc[0] = *to; 1398 arc[1] = *control; 1399 arc[2] = stroker->center; 1400 1401 while ( arc >= bez_stack ) 1402 { 1403 FT_Angle angle_in, angle_out; 1404 1405 1406 /* initialize with current direction */ 1407 angle_in = angle_out = stroker->angle_in; 1408 1409 if ( arc < limit && 1410 !ft_conic_is_small_enough( arc, &angle_in, &angle_out ) ) 1411 { 1412 if ( stroker->first_point ) 1413 stroker->angle_in = angle_in; 1414 1415 ft_conic_split( arc ); 1416 arc += 2; 1417 continue; 1418 } 1419 1420 if ( first_arc ) 1421 { 1422 first_arc = FALSE; 1423 1424 /* process corner if necessary */ 1425 if ( stroker->first_point ) 1426 error = ft_stroker_subpath_start( stroker, angle_in, 0 ); 1427 else 1428 { 1429 stroker->angle_out = angle_in; 1430 error = ft_stroker_process_corner( stroker, 0 ); 1431 } 1432 } 1433 else if ( ft_pos_abs( FT_Angle_Diff( stroker->angle_in, angle_in ) ) > 1434 FT_SMALL_CONIC_THRESHOLD / 4 ) 1435 { 1436 /* if the deviation from one arc to the next is too great, */ 1437 /* add a round corner */ 1438 stroker->center = arc[2]; 1439 stroker->angle_out = angle_in; 1440 stroker->line_join = FT_STROKER_LINEJOIN_ROUND; 1441 1442 error = ft_stroker_process_corner( stroker, 0 ); 1443 1444 /* reinstate line join style */ 1445 stroker->line_join = stroker->line_join_saved; 1446 } 1447 1448 if ( error ) 1449 goto Exit; 1450 1451 /* the arc's angle is small enough; we can add it directly to each */ 1452 /* border */ 1453 { 1454 FT_Vector ctrl, end; 1455 FT_Angle theta, phi, rotate, alpha0 = 0; 1456 FT_Fixed length; 1457 FT_StrokeBorder border; 1458 FT_Int side; 1459 1460 1461 theta = FT_Angle_Diff( angle_in, angle_out ) / 2; 1462 phi = angle_in + theta; 1463 length = FT_DivFix( stroker->radius, FT_Cos( theta ) ); 1464 1465 /* compute direction of original arc */ 1466 if ( stroker->handle_wide_strokes ) 1467 alpha0 = FT_Atan2( arc[0].x - arc[2].x, arc[0].y - arc[2].y ); 1468 1469 for ( border = stroker->borders, side = 0; 1470 side <= 1; 1471 side++, border++ ) 1472 { 1473 rotate = FT_SIDE_TO_ROTATE( side ); 1474 1475 /* compute control point */ 1476 FT_Vector_From_Polar( &ctrl, length, phi + rotate ); 1477 ctrl.x += arc[1].x; 1478 ctrl.y += arc[1].y; 1479 1480 /* compute end point */ 1481 FT_Vector_From_Polar( &end, stroker->radius, angle_out + rotate ); 1482 end.x += arc[0].x; 1483 end.y += arc[0].y; 1484 1485 if ( stroker->handle_wide_strokes ) 1486 { 1487 FT_Vector start; 1488 FT_Angle alpha1; 1489 1490 1491 /* determine whether the border radius is greater than the */ 1492 /* radius of curvature of the original arc */ 1493 start = border->points[border->num_points - 1]; 1494 1495 alpha1 = FT_Atan2( end.x - start.x, end.y - start.y ); 1496 1497 /* is the direction of the border arc opposite to */ 1498 /* that of the original arc? */ 1499 if ( ft_pos_abs( FT_Angle_Diff( alpha0, alpha1 ) ) > 1500 FT_ANGLE_PI / 2 ) 1501 { 1502 FT_Angle beta, gamma; 1503 FT_Vector bvec, delta; 1504 FT_Fixed blen, sinA, sinB, alen; 1505 1506 1507 /* use the sine rule to find the intersection point */ 1508 beta = FT_Atan2( arc[2].x - start.x, arc[2].y - start.y ); 1509 gamma = FT_Atan2( arc[0].x - end.x, arc[0].y - end.y ); 1510 1511 bvec.x = end.x - start.x; 1512 bvec.y = end.y - start.y; 1513 1514 blen = FT_Vector_Length( &bvec ); 1515 1516 sinA = ft_pos_abs( FT_Sin( alpha1 - gamma ) ); 1517 sinB = ft_pos_abs( FT_Sin( beta - gamma ) ); 1518 1519 alen = FT_MulDiv( blen, sinA, sinB ); 1520 1521 FT_Vector_From_Polar( &delta, alen, beta ); 1522 delta.x += start.x; 1523 delta.y += start.y; 1524 1525 /* circumnavigate the negative sector backwards */ 1526 border->movable = FALSE; 1527 error = ft_stroke_border_lineto( border, &delta, FALSE ); 1528 if ( error ) 1529 goto Exit; 1530 error = ft_stroke_border_lineto( border, &end, FALSE ); 1531 if ( error ) 1532 goto Exit; 1533 error = ft_stroke_border_conicto( border, &ctrl, &start ); 1534 if ( error ) 1535 goto Exit; 1536 /* and then move to the endpoint */ 1537 error = ft_stroke_border_lineto( border, &end, FALSE ); 1538 if ( error ) 1539 goto Exit; 1540 1541 continue; 1542 } 1543 1544 /* else fall through */ 1545 } 1546 1547 /* simply add an arc */ 1548 error = ft_stroke_border_conicto( border, &ctrl, &end ); 1549 if ( error ) 1550 goto Exit; 1551 } 1552 } 1553 1554 arc -= 2; 1555 1556 stroker->angle_in = angle_out; 1557 } 1558 1559 stroker->center = *to; 1560 1561 Exit: 1562 return error; 1563 } 1564 1565 1566 /* documentation is in ftstroke.h */ 1567 1568 FT_EXPORT_DEF( FT_Error ) 1569 FT_Stroker_CubicTo( FT_Stroker stroker, 1570 FT_Vector* control1, 1571 FT_Vector* control2, 1572 FT_Vector* to ) 1573 { 1574 FT_Error error = FT_Err_Ok; 1575 FT_Vector bez_stack[37]; 1576 FT_Vector* arc; 1577 FT_Vector* limit = bez_stack + 32; 1578 FT_Bool first_arc = TRUE; 1579 1580 1581 if ( !stroker || !control1 || !control2 || !to ) 1582 { 1583 error = FT_THROW( Invalid_Argument ); 1584 goto Exit; 1585 } 1586 1587 /* if all control points are coincident, this is a no-op; */ 1588 /* avoid creating a spurious corner */ 1589 if ( FT_IS_SMALL( stroker->center.x - control1->x ) && 1590 FT_IS_SMALL( stroker->center.y - control1->y ) && 1591 FT_IS_SMALL( control1->x - control2->x ) && 1592 FT_IS_SMALL( control1->y - control2->y ) && 1593 FT_IS_SMALL( control2->x - to->x ) && 1594 FT_IS_SMALL( control2->y - to->y ) ) 1595 { 1596 stroker->center = *to; 1597 goto Exit; 1598 } 1599 1600 arc = bez_stack; 1601 arc[0] = *to; 1602 arc[1] = *control2; 1603 arc[2] = *control1; 1604 arc[3] = stroker->center; 1605 1606 while ( arc >= bez_stack ) 1607 { 1608 FT_Angle angle_in, angle_mid, angle_out; 1609 1610 1611 /* initialize with current direction */ 1612 angle_in = angle_out = angle_mid = stroker->angle_in; 1613 1614 if ( arc < limit && 1615 !ft_cubic_is_small_enough( arc, &angle_in, 1616 &angle_mid, &angle_out ) ) 1617 { 1618 if ( stroker->first_point ) 1619 stroker->angle_in = angle_in; 1620 1621 ft_cubic_split( arc ); 1622 arc += 3; 1623 continue; 1624 } 1625 1626 if ( first_arc ) 1627 { 1628 first_arc = FALSE; 1629 1630 /* process corner if necessary */ 1631 if ( stroker->first_point ) 1632 error = ft_stroker_subpath_start( stroker, angle_in, 0 ); 1633 else 1634 { 1635 stroker->angle_out = angle_in; 1636 error = ft_stroker_process_corner( stroker, 0 ); 1637 } 1638 } 1639 else if ( ft_pos_abs( FT_Angle_Diff( stroker->angle_in, angle_in ) ) > 1640 FT_SMALL_CUBIC_THRESHOLD / 4 ) 1641 { 1642 /* if the deviation from one arc to the next is too great, */ 1643 /* add a round corner */ 1644 stroker->center = arc[3]; 1645 stroker->angle_out = angle_in; 1646 stroker->line_join = FT_STROKER_LINEJOIN_ROUND; 1647 1648 error = ft_stroker_process_corner( stroker, 0 ); 1649 1650 /* reinstate line join style */ 1651 stroker->line_join = stroker->line_join_saved; 1652 } 1653 1654 if ( error ) 1655 goto Exit; 1656 1657 /* the arc's angle is small enough; we can add it directly to each */ 1658 /* border */ 1659 { 1660 FT_Vector ctrl1, ctrl2, end; 1661 FT_Angle theta1, phi1, theta2, phi2, rotate, alpha0 = 0; 1662 FT_Fixed length1, length2; 1663 FT_StrokeBorder border; 1664 FT_Int side; 1665 1666 1667 theta1 = FT_Angle_Diff( angle_in, angle_mid ) / 2; 1668 theta2 = FT_Angle_Diff( angle_mid, angle_out ) / 2; 1669 phi1 = ft_angle_mean( angle_in, angle_mid ); 1670 phi2 = ft_angle_mean( angle_mid, angle_out ); 1671 length1 = FT_DivFix( stroker->radius, FT_Cos( theta1 ) ); 1672 length2 = FT_DivFix( stroker->radius, FT_Cos( theta2 ) ); 1673 1674 /* compute direction of original arc */ 1675 if ( stroker->handle_wide_strokes ) 1676 alpha0 = FT_Atan2( arc[0].x - arc[3].x, arc[0].y - arc[3].y ); 1677 1678 for ( border = stroker->borders, side = 0; 1679 side <= 1; 1680 side++, border++ ) 1681 { 1682 rotate = FT_SIDE_TO_ROTATE( side ); 1683 1684 /* compute control points */ 1685 FT_Vector_From_Polar( &ctrl1, length1, phi1 + rotate ); 1686 ctrl1.x += arc[2].x; 1687 ctrl1.y += arc[2].y; 1688 1689 FT_Vector_From_Polar( &ctrl2, length2, phi2 + rotate ); 1690 ctrl2.x += arc[1].x; 1691 ctrl2.y += arc[1].y; 1692 1693 /* compute end point */ 1694 FT_Vector_From_Polar( &end, stroker->radius, angle_out + rotate ); 1695 end.x += arc[0].x; 1696 end.y += arc[0].y; 1697 1698 if ( stroker->handle_wide_strokes ) 1699 { 1700 FT_Vector start; 1701 FT_Angle alpha1; 1702 1703 1704 /* determine whether the border radius is greater than the */ 1705 /* radius of curvature of the original arc */ 1706 start = border->points[border->num_points - 1]; 1707 1708 alpha1 = FT_Atan2( end.x - start.x, end.y - start.y ); 1709 1710 /* is the direction of the border arc opposite to */ 1711 /* that of the original arc? */ 1712 if ( ft_pos_abs( FT_Angle_Diff( alpha0, alpha1 ) ) > 1713 FT_ANGLE_PI / 2 ) 1714 { 1715 FT_Angle beta, gamma; 1716 FT_Vector bvec, delta; 1717 FT_Fixed blen, sinA, sinB, alen; 1718 1719 1720 /* use the sine rule to find the intersection point */ 1721 beta = FT_Atan2( arc[3].x - start.x, arc[3].y - start.y ); 1722 gamma = FT_Atan2( arc[0].x - end.x, arc[0].y - end.y ); 1723 1724 bvec.x = end.x - start.x; 1725 bvec.y = end.y - start.y; 1726 1727 blen = FT_Vector_Length( &bvec ); 1728 1729 sinA = ft_pos_abs( FT_Sin( alpha1 - gamma ) ); 1730 sinB = ft_pos_abs( FT_Sin( beta - gamma ) ); 1731 1732 alen = FT_MulDiv( blen, sinA, sinB ); 1733 1734 FT_Vector_From_Polar( &delta, alen, beta ); 1735 delta.x += start.x; 1736 delta.y += start.y; 1737 1738 /* circumnavigate the negative sector backwards */ 1739 border->movable = FALSE; 1740 error = ft_stroke_border_lineto( border, &delta, FALSE ); 1741 if ( error ) 1742 goto Exit; 1743 error = ft_stroke_border_lineto( border, &end, FALSE ); 1744 if ( error ) 1745 goto Exit; 1746 error = ft_stroke_border_cubicto( border, 1747 &ctrl2, 1748 &ctrl1, 1749 &start ); 1750 if ( error ) 1751 goto Exit; 1752 /* and then move to the endpoint */ 1753 error = ft_stroke_border_lineto( border, &end, FALSE ); 1754 if ( error ) 1755 goto Exit; 1756 1757 continue; 1758 } 1759 1760 /* else fall through */ 1761 } 1762 1763 /* simply add an arc */ 1764 error = ft_stroke_border_cubicto( border, &ctrl1, &ctrl2, &end ); 1765 if ( error ) 1766 goto Exit; 1767 } 1768 } 1769 1770 arc -= 3; 1771 1772 stroker->angle_in = angle_out; 1773 } 1774 1775 stroker->center = *to; 1776 1777 Exit: 1778 return error; 1779 } 1780 1781 1782 /* documentation is in ftstroke.h */ 1783 1784 FT_EXPORT_DEF( FT_Error ) 1785 FT_Stroker_BeginSubPath( FT_Stroker stroker, 1786 FT_Vector* to, 1787 FT_Bool open ) 1788 { 1789 if ( !stroker || !to ) 1790 return FT_THROW( Invalid_Argument ); 1791 1792 /* We cannot process the first point, because there is not enough */ 1793 /* information regarding its corner/cap. The latter will be processed */ 1794 /* in the `FT_Stroker_EndSubPath' routine. */ 1795 /* */ 1796 stroker->first_point = TRUE; 1797 stroker->center = *to; 1798 stroker->subpath_open = open; 1799 1800 /* Determine if we need to check whether the border radius is greater */ 1801 /* than the radius of curvature of a curve, to handle this case */ 1802 /* specially. This is only required if bevel joins or butt caps may */ 1803 /* be created, because round & miter joins and round & square caps */ 1804 /* cover the negative sector created with wide strokes. */ 1805 stroker->handle_wide_strokes = 1806 FT_BOOL( stroker->line_join != FT_STROKER_LINEJOIN_ROUND || 1807 ( stroker->subpath_open && 1808 stroker->line_cap == FT_STROKER_LINECAP_BUTT ) ); 1809 1810 /* record the subpath start point for each border */ 1811 stroker->subpath_start = *to; 1812 1813 stroker->angle_in = 0; 1814 1815 return FT_Err_Ok; 1816 } 1817 1818 1819 static FT_Error 1820 ft_stroker_add_reverse_left( FT_Stroker stroker, 1821 FT_Bool open ) 1822 { 1823 FT_StrokeBorder right = stroker->borders + 0; 1824 FT_StrokeBorder left = stroker->borders + 1; 1825 FT_Int new_points; 1826 FT_Error error = FT_Err_Ok; 1827 1828 1829 FT_ASSERT( left->start >= 0 ); 1830 1831 new_points = (FT_Int)left->num_points - left->start; 1832 if ( new_points > 0 ) 1833 { 1834 error = ft_stroke_border_grow( right, (FT_UInt)new_points ); 1835 if ( error ) 1836 goto Exit; 1837 1838 { 1839 FT_Vector* dst_point = right->points + right->num_points; 1840 FT_Byte* dst_tag = right->tags + right->num_points; 1841 FT_Vector* src_point = left->points + left->num_points - 1; 1842 FT_Byte* src_tag = left->tags + left->num_points - 1; 1843 1844 1845 while ( src_point >= left->points + left->start ) 1846 { 1847 *dst_point = *src_point; 1848 *dst_tag = *src_tag; 1849 1850 if ( open ) 1851 dst_tag[0] &= ~FT_STROKE_TAG_BEGIN_END; 1852 else 1853 { 1854 FT_Byte ttag = 1855 (FT_Byte)( dst_tag[0] & FT_STROKE_TAG_BEGIN_END ); 1856 1857 1858 /* switch begin/end tags if necessary */ 1859 if ( ttag == FT_STROKE_TAG_BEGIN || 1860 ttag == FT_STROKE_TAG_END ) 1861 dst_tag[0] ^= FT_STROKE_TAG_BEGIN_END; 1862 } 1863 1864 src_point--; 1865 src_tag--; 1866 dst_point++; 1867 dst_tag++; 1868 } 1869 } 1870 1871 left->num_points = (FT_UInt)left->start; 1872 right->num_points += (FT_UInt)new_points; 1873 1874 right->movable = FALSE; 1875 left->movable = FALSE; 1876 } 1877 1878 Exit: 1879 return error; 1880 } 1881 1882 1883 /* documentation is in ftstroke.h */ 1884 1885 /* there's a lot of magic in this function! */ 1886 FT_EXPORT_DEF( FT_Error ) 1887 FT_Stroker_EndSubPath( FT_Stroker stroker ) 1888 { 1889 FT_Error error = FT_Err_Ok; 1890 1891 1892 if ( !stroker ) 1893 { 1894 error = FT_THROW( Invalid_Argument ); 1895 goto Exit; 1896 } 1897 1898 if ( stroker->subpath_open ) 1899 { 1900 FT_StrokeBorder right = stroker->borders; 1901 1902 1903 /* All right, this is an opened path, we need to add a cap between */ 1904 /* right & left, add the reverse of left, then add a final cap */ 1905 /* between left & right. */ 1906 error = ft_stroker_cap( stroker, stroker->angle_in, 0 ); 1907 if ( error ) 1908 goto Exit; 1909 1910 /* add reversed points from `left' to `right' */ 1911 error = ft_stroker_add_reverse_left( stroker, TRUE ); 1912 if ( error ) 1913 goto Exit; 1914 1915 /* now add the final cap */ 1916 stroker->center = stroker->subpath_start; 1917 error = ft_stroker_cap( stroker, 1918 stroker->subpath_angle + FT_ANGLE_PI, 0 ); 1919 if ( error ) 1920 goto Exit; 1921 1922 /* Now end the right subpath accordingly. The left one is */ 1923 /* rewind and doesn't need further processing. */ 1924 ft_stroke_border_close( right, FALSE ); 1925 } 1926 else 1927 { 1928 FT_Angle turn; 1929 FT_Int inside_side; 1930 1931 1932 /* close the path if needed */ 1933 if ( stroker->center.x != stroker->subpath_start.x || 1934 stroker->center.y != stroker->subpath_start.y ) 1935 { 1936 error = FT_Stroker_LineTo( stroker, &stroker->subpath_start ); 1937 if ( error ) 1938 goto Exit; 1939 } 1940 1941 /* process the corner */ 1942 stroker->angle_out = stroker->subpath_angle; 1943 turn = FT_Angle_Diff( stroker->angle_in, 1944 stroker->angle_out ); 1945 1946 /* no specific corner processing is required if the turn is 0 */ 1947 if ( turn != 0 ) 1948 { 1949 /* when we turn to the right, the inside side is 0 */ 1950 /* otherwise, the inside side is 1 */ 1951 inside_side = ( turn < 0 ); 1952 1953 error = ft_stroker_inside( stroker, 1954 inside_side, 1955 stroker->subpath_line_length ); 1956 if ( error ) 1957 goto Exit; 1958 1959 /* process the outside side */ 1960 error = ft_stroker_outside( stroker, 1961 !inside_side, 1962 stroker->subpath_line_length ); 1963 if ( error ) 1964 goto Exit; 1965 } 1966 1967 /* then end our two subpaths */ 1968 ft_stroke_border_close( stroker->borders + 0, FALSE ); 1969 ft_stroke_border_close( stroker->borders + 1, TRUE ); 1970 } 1971 1972 Exit: 1973 return error; 1974 } 1975 1976 1977 /* documentation is in ftstroke.h */ 1978 1979 FT_EXPORT_DEF( FT_Error ) 1980 FT_Stroker_GetBorderCounts( FT_Stroker stroker, 1981 FT_StrokerBorder border, 1982 FT_UInt *anum_points, 1983 FT_UInt *anum_contours ) 1984 { 1985 FT_UInt num_points = 0, num_contours = 0; 1986 FT_Error error; 1987 1988 1989 if ( !stroker || border > 1 ) 1990 { 1991 error = FT_THROW( Invalid_Argument ); 1992 goto Exit; 1993 } 1994 1995 error = ft_stroke_border_get_counts( stroker->borders + border, 1996 &num_points, &num_contours ); 1997 Exit: 1998 if ( anum_points ) 1999 *anum_points = num_points; 2000 2001 if ( anum_contours ) 2002 *anum_contours = num_contours; 2003 2004 return error; 2005 } 2006 2007 2008 /* documentation is in ftstroke.h */ 2009 2010 FT_EXPORT_DEF( FT_Error ) 2011 FT_Stroker_GetCounts( FT_Stroker stroker, 2012 FT_UInt *anum_points, 2013 FT_UInt *anum_contours ) 2014 { 2015 FT_UInt count1, count2, num_points = 0; 2016 FT_UInt count3, count4, num_contours = 0; 2017 FT_Error error; 2018 2019 2020 if ( !stroker ) 2021 { 2022 error = FT_THROW( Invalid_Argument ); 2023 goto Exit; 2024 } 2025 2026 error = ft_stroke_border_get_counts( stroker->borders + 0, 2027 &count1, &count2 ); 2028 if ( error ) 2029 goto Exit; 2030 2031 error = ft_stroke_border_get_counts( stroker->borders + 1, 2032 &count3, &count4 ); 2033 if ( error ) 2034 goto Exit; 2035 2036 num_points = count1 + count3; 2037 num_contours = count2 + count4; 2038 2039 Exit: 2040 if ( anum_points ) 2041 *anum_points = num_points; 2042 2043 if ( anum_contours ) 2044 *anum_contours = num_contours; 2045 2046 return error; 2047 } 2048 2049 2050 /* documentation is in ftstroke.h */ 2051 2052 FT_EXPORT_DEF( void ) 2053 FT_Stroker_ExportBorder( FT_Stroker stroker, 2054 FT_StrokerBorder border, 2055 FT_Outline* outline ) 2056 { 2057 if ( !stroker || !outline ) 2058 return; 2059 2060 if ( border == FT_STROKER_BORDER_LEFT || 2061 border == FT_STROKER_BORDER_RIGHT ) 2062 { 2063 FT_StrokeBorder sborder = & stroker->borders[border]; 2064 2065 2066 if ( sborder->valid ) 2067 ft_stroke_border_export( sborder, outline ); 2068 } 2069 } 2070 2071 2072 /* documentation is in ftstroke.h */ 2073 2074 FT_EXPORT_DEF( void ) 2075 FT_Stroker_Export( FT_Stroker stroker, 2076 FT_Outline* outline ) 2077 { 2078 FT_Stroker_ExportBorder( stroker, FT_STROKER_BORDER_LEFT, outline ); 2079 FT_Stroker_ExportBorder( stroker, FT_STROKER_BORDER_RIGHT, outline ); 2080 } 2081 2082 2083 /* documentation is in ftstroke.h */ 2084 2085 /* 2086 * The following is very similar to FT_Outline_Decompose, except 2087 * that we do support opened paths, and do not scale the outline. 2088 */ 2089 FT_EXPORT_DEF( FT_Error ) 2090 FT_Stroker_ParseOutline( FT_Stroker stroker, 2091 FT_Outline* outline, 2092 FT_Bool opened ) 2093 { 2094 FT_Vector v_last; 2095 FT_Vector v_control; 2096 FT_Vector v_start; 2097 2098 FT_Vector* point; 2099 FT_Vector* limit; 2100 char* tags; 2101 2102 FT_Error error; 2103 2104 FT_Int n; /* index of contour in outline */ 2105 FT_UInt first; /* index of first point in contour */ 2106 FT_Int tag; /* current point's state */ 2107 2108 2109 if ( !outline ) 2110 return FT_THROW( Invalid_Outline ); 2111 2112 if ( !stroker ) 2113 return FT_THROW( Invalid_Argument ); 2114 2115 FT_Stroker_Rewind( stroker ); 2116 2117 first = 0; 2118 2119 for ( n = 0; n < outline->n_contours; n++ ) 2120 { 2121 FT_UInt last; /* index of last point in contour */ 2122 2123 2124 last = (FT_UInt)outline->contours[n]; 2125 limit = outline->points + last; 2126 2127 /* skip empty points; we don't stroke these */ 2128 if ( last <= first ) 2129 { 2130 first = last + 1; 2131 continue; 2132 } 2133 2134 v_start = outline->points[first]; 2135 v_last = outline->points[last]; 2136 2137 v_control = v_start; 2138 2139 point = outline->points + first; 2140 tags = outline->tags + first; 2141 tag = FT_CURVE_TAG( tags[0] ); 2142 2143 /* A contour cannot start with a cubic control point! */ 2144 if ( tag == FT_CURVE_TAG_CUBIC ) 2145 goto Invalid_Outline; 2146 2147 /* check first point to determine origin */ 2148 if ( tag == FT_CURVE_TAG_CONIC ) 2149 { 2150 /* First point is conic control. Yes, this happens. */ 2151 if ( FT_CURVE_TAG( outline->tags[last] ) == FT_CURVE_TAG_ON ) 2152 { 2153 /* start at last point if it is on the curve */ 2154 v_start = v_last; 2155 limit--; 2156 } 2157 else 2158 { 2159 /* if both first and last points are conic, */ 2160 /* start at their middle */ 2161 v_start.x = ( v_start.x + v_last.x ) / 2; 2162 v_start.y = ( v_start.y + v_last.y ) / 2; 2163 } 2164 point--; 2165 tags--; 2166 } 2167 2168 error = FT_Stroker_BeginSubPath( stroker, &v_start, opened ); 2169 if ( error ) 2170 goto Exit; 2171 2172 while ( point < limit ) 2173 { 2174 point++; 2175 tags++; 2176 2177 tag = FT_CURVE_TAG( tags[0] ); 2178 switch ( tag ) 2179 { 2180 case FT_CURVE_TAG_ON: /* emit a single line_to */ 2181 { 2182 FT_Vector vec; 2183 2184 2185 vec.x = point->x; 2186 vec.y = point->y; 2187 2188 error = FT_Stroker_LineTo( stroker, &vec ); 2189 if ( error ) 2190 goto Exit; 2191 continue; 2192 } 2193 2194 case FT_CURVE_TAG_CONIC: /* consume conic arcs */ 2195 v_control.x = point->x; 2196 v_control.y = point->y; 2197 2198 Do_Conic: 2199 if ( point < limit ) 2200 { 2201 FT_Vector vec; 2202 FT_Vector v_middle; 2203 2204 2205 point++; 2206 tags++; 2207 tag = FT_CURVE_TAG( tags[0] ); 2208 2209 vec = point[0]; 2210 2211 if ( tag == FT_CURVE_TAG_ON ) 2212 { 2213 error = FT_Stroker_ConicTo( stroker, &v_control, &vec ); 2214 if ( error ) 2215 goto Exit; 2216 continue; 2217 } 2218 2219 if ( tag != FT_CURVE_TAG_CONIC ) 2220 goto Invalid_Outline; 2221 2222 v_middle.x = ( v_control.x + vec.x ) / 2; 2223 v_middle.y = ( v_control.y + vec.y ) / 2; 2224 2225 error = FT_Stroker_ConicTo( stroker, &v_control, &v_middle ); 2226 if ( error ) 2227 goto Exit; 2228 2229 v_control = vec; 2230 goto Do_Conic; 2231 } 2232 2233 error = FT_Stroker_ConicTo( stroker, &v_control, &v_start ); 2234 goto Close; 2235 2236 default: /* FT_CURVE_TAG_CUBIC */ 2237 { 2238 FT_Vector vec1, vec2; 2239 2240 2241 if ( point + 1 > limit || 2242 FT_CURVE_TAG( tags[1] ) != FT_CURVE_TAG_CUBIC ) 2243 goto Invalid_Outline; 2244 2245 point += 2; 2246 tags += 2; 2247 2248 vec1 = point[-2]; 2249 vec2 = point[-1]; 2250 2251 if ( point <= limit ) 2252 { 2253 FT_Vector vec; 2254 2255 2256 vec = point[0]; 2257 2258 error = FT_Stroker_CubicTo( stroker, &vec1, &vec2, &vec ); 2259 if ( error ) 2260 goto Exit; 2261 continue; 2262 } 2263 2264 error = FT_Stroker_CubicTo( stroker, &vec1, &vec2, &v_start ); 2265 goto Close; 2266 } 2267 } 2268 } 2269 2270 Close: 2271 if ( error ) 2272 goto Exit; 2273 2274 /* don't try to end the path if no segments have been generated */ 2275 if ( !stroker->first_point ) 2276 { 2277 error = FT_Stroker_EndSubPath( stroker ); 2278 if ( error ) 2279 goto Exit; 2280 } 2281 2282 first = last + 1; 2283 } 2284 2285 return FT_Err_Ok; 2286 2287 Exit: 2288 return error; 2289 2290 Invalid_Outline: 2291 return FT_THROW( Invalid_Outline ); 2292 } 2293 2294 2295 /* documentation is in ftstroke.h */ 2296 2297 FT_EXPORT_DEF( FT_Error ) 2298 FT_Glyph_Stroke( FT_Glyph *pglyph, 2299 FT_Stroker stroker, 2300 FT_Bool destroy ) 2301 { 2302 FT_Error error = FT_ERR( Invalid_Argument ); 2303 FT_Glyph glyph = NULL; 2304 2305 2306 if ( !pglyph ) 2307 goto Exit; 2308 2309 glyph = *pglyph; 2310 if ( !glyph || glyph->clazz != &ft_outline_glyph_class ) 2311 goto Exit; 2312 2313 { 2314 FT_Glyph copy; 2315 2316 2317 error = FT_Glyph_Copy( glyph, © ); 2318 if ( error ) 2319 goto Exit; 2320 2321 glyph = copy; 2322 } 2323 2324 { 2325 FT_OutlineGlyph oglyph = (FT_OutlineGlyph)glyph; 2326 FT_Outline* outline = &oglyph->outline; 2327 FT_UInt num_points, num_contours; 2328 2329 2330 error = FT_Stroker_ParseOutline( stroker, outline, FALSE ); 2331 if ( error ) 2332 goto Fail; 2333 2334 FT_Stroker_GetCounts( stroker, &num_points, &num_contours ); 2335 2336 FT_Outline_Done( glyph->library, outline ); 2337 2338 error = FT_Outline_New( glyph->library, 2339 num_points, 2340 (FT_Int)num_contours, 2341 outline ); 2342 if ( error ) 2343 goto Fail; 2344 2345 outline->n_points = 0; 2346 outline->n_contours = 0; 2347 2348 FT_Stroker_Export( stroker, outline ); 2349 } 2350 2351 if ( destroy ) 2352 FT_Done_Glyph( *pglyph ); 2353 2354 *pglyph = glyph; 2355 goto Exit; 2356 2357 Fail: 2358 FT_Done_Glyph( glyph ); 2359 glyph = NULL; 2360 2361 if ( !destroy ) 2362 *pglyph = NULL; 2363 2364 Exit: 2365 return error; 2366 } 2367 2368 2369 /* documentation is in ftstroke.h */ 2370 2371 FT_EXPORT_DEF( FT_Error ) 2372 FT_Glyph_StrokeBorder( FT_Glyph *pglyph, 2373 FT_Stroker stroker, 2374 FT_Bool inside, 2375 FT_Bool destroy ) 2376 { 2377 FT_Error error = FT_ERR( Invalid_Argument ); 2378 FT_Glyph glyph = NULL; 2379 2380 2381 if ( !pglyph ) 2382 goto Exit; 2383 2384 glyph = *pglyph; 2385 if ( !glyph || glyph->clazz != &ft_outline_glyph_class ) 2386 goto Exit; 2387 2388 { 2389 FT_Glyph copy; 2390 2391 2392 error = FT_Glyph_Copy( glyph, © ); 2393 if ( error ) 2394 goto Exit; 2395 2396 glyph = copy; 2397 } 2398 2399 { 2400 FT_OutlineGlyph oglyph = (FT_OutlineGlyph)glyph; 2401 FT_StrokerBorder border; 2402 FT_Outline* outline = &oglyph->outline; 2403 FT_UInt num_points, num_contours; 2404 2405 2406 border = FT_Outline_GetOutsideBorder( outline ); 2407 if ( inside ) 2408 { 2409 if ( border == FT_STROKER_BORDER_LEFT ) 2410 border = FT_STROKER_BORDER_RIGHT; 2411 else 2412 border = FT_STROKER_BORDER_LEFT; 2413 } 2414 2415 error = FT_Stroker_ParseOutline( stroker, outline, FALSE ); 2416 if ( error ) 2417 goto Fail; 2418 2419 FT_Stroker_GetBorderCounts( stroker, border, 2420 &num_points, &num_contours ); 2421 2422 FT_Outline_Done( glyph->library, outline ); 2423 2424 error = FT_Outline_New( glyph->library, 2425 num_points, 2426 (FT_Int)num_contours, 2427 outline ); 2428 if ( error ) 2429 goto Fail; 2430 2431 outline->n_points = 0; 2432 outline->n_contours = 0; 2433 2434 FT_Stroker_ExportBorder( stroker, border, outline ); 2435 } 2436 2437 if ( destroy ) 2438 FT_Done_Glyph( *pglyph ); 2439 2440 *pglyph = glyph; 2441 goto Exit; 2442 2443 Fail: 2444 FT_Done_Glyph( glyph ); 2445 glyph = NULL; 2446 2447 if ( !destroy ) 2448 *pglyph = NULL; 2449 2450 Exit: 2451 return error; 2452 } 2453 2454 2455 /* END */