1 /**************************************************************************** 2 * 3 * ftstroke.c 4 * 5 * FreeType path stroker (body). 6 * 7 * Copyright (C) 2002-2020 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 ) FT_Outline_GetInsideBorder(FT_Outline * outline)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 ) FT_Outline_GetOutsideBorder(FT_Outline * outline)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 ft_pos_abs(FT_Pos x)76 ft_pos_abs( FT_Pos x ) 77 { 78 return x >= 0 ? x : -x; 79 } 80 81 82 static void ft_conic_split(FT_Vector * base)83 ft_conic_split( FT_Vector* base ) 84 { 85 FT_Pos a, b; 86 87 88 base[4].x = base[2].x; 89 a = base[0].x + base[1].x; 90 b = base[1].x + base[2].x; 91 base[3].x = b >> 1; 92 base[2].x = ( a + b ) >> 2; 93 base[1].x = a >> 1; 94 95 base[4].y = base[2].y; 96 a = base[0].y + base[1].y; 97 b = base[1].y + base[2].y; 98 base[3].y = b >> 1; 99 base[2].y = ( a + b ) >> 2; 100 base[1].y = a >> 1; 101 } 102 103 104 static FT_Bool ft_conic_is_small_enough(FT_Vector * base,FT_Angle * angle_in,FT_Angle * angle_out)105 ft_conic_is_small_enough( FT_Vector* base, 106 FT_Angle *angle_in, 107 FT_Angle *angle_out ) 108 { 109 FT_Vector d1, d2; 110 FT_Angle theta; 111 FT_Int close1, close2; 112 113 114 d1.x = base[1].x - base[2].x; 115 d1.y = base[1].y - base[2].y; 116 d2.x = base[0].x - base[1].x; 117 d2.y = base[0].y - base[1].y; 118 119 close1 = FT_IS_SMALL( d1.x ) && FT_IS_SMALL( d1.y ); 120 close2 = FT_IS_SMALL( d2.x ) && FT_IS_SMALL( d2.y ); 121 122 if ( close1 ) 123 { 124 if ( close2 ) 125 { 126 /* basically a point; */ 127 /* do nothing to retain original direction */ 128 } 129 else 130 { 131 *angle_in = 132 *angle_out = FT_Atan2( d2.x, d2.y ); 133 } 134 } 135 else /* !close1 */ 136 { 137 if ( close2 ) 138 { 139 *angle_in = 140 *angle_out = FT_Atan2( d1.x, d1.y ); 141 } 142 else 143 { 144 *angle_in = FT_Atan2( d1.x, d1.y ); 145 *angle_out = FT_Atan2( d2.x, d2.y ); 146 } 147 } 148 149 theta = ft_pos_abs( FT_Angle_Diff( *angle_in, *angle_out ) ); 150 151 return FT_BOOL( theta < FT_SMALL_CONIC_THRESHOLD ); 152 } 153 154 155 static void ft_cubic_split(FT_Vector * base)156 ft_cubic_split( FT_Vector* base ) 157 { 158 FT_Pos a, b, c; 159 160 161 base[6].x = base[3].x; 162 a = base[0].x + base[1].x; 163 b = base[1].x + base[2].x; 164 c = base[2].x + base[3].x; 165 base[5].x = c >> 1; 166 c += b; 167 base[4].x = c >> 2; 168 base[1].x = a >> 1; 169 a += b; 170 base[2].x = a >> 2; 171 base[3].x = ( a + c ) >> 3; 172 173 base[6].y = base[3].y; 174 a = base[0].y + base[1].y; 175 b = base[1].y + base[2].y; 176 c = base[2].y + base[3].y; 177 base[5].y = c >> 1; 178 c += b; 179 base[4].y = c >> 2; 180 base[1].y = a >> 1; 181 a += b; 182 base[2].y = a >> 2; 183 base[3].y = ( a + c ) >> 3; 184 } 185 186 187 /* Return the average of `angle1' and `angle2'. */ 188 /* This gives correct result even if `angle1' and `angle2' */ 189 /* have opposite signs. */ 190 static FT_Angle ft_angle_mean(FT_Angle angle1,FT_Angle angle2)191 ft_angle_mean( FT_Angle angle1, 192 FT_Angle angle2 ) 193 { 194 return angle1 + FT_Angle_Diff( angle1, angle2 ) / 2; 195 } 196 197 198 static FT_Bool ft_cubic_is_small_enough(FT_Vector * base,FT_Angle * angle_in,FT_Angle * angle_mid,FT_Angle * angle_out)199 ft_cubic_is_small_enough( FT_Vector* base, 200 FT_Angle *angle_in, 201 FT_Angle *angle_mid, 202 FT_Angle *angle_out ) 203 { 204 FT_Vector d1, d2, d3; 205 FT_Angle theta1, theta2; 206 FT_Int close1, close2, close3; 207 208 209 d1.x = base[2].x - base[3].x; 210 d1.y = base[2].y - base[3].y; 211 d2.x = base[1].x - base[2].x; 212 d2.y = base[1].y - base[2].y; 213 d3.x = base[0].x - base[1].x; 214 d3.y = base[0].y - base[1].y; 215 216 close1 = FT_IS_SMALL( d1.x ) && FT_IS_SMALL( d1.y ); 217 close2 = FT_IS_SMALL( d2.x ) && FT_IS_SMALL( d2.y ); 218 close3 = FT_IS_SMALL( d3.x ) && FT_IS_SMALL( d3.y ); 219 220 if ( close1 ) 221 { 222 if ( close2 ) 223 { 224 if ( close3 ) 225 { 226 /* basically a point; */ 227 /* do nothing to retain original direction */ 228 } 229 else /* !close3 */ 230 { 231 *angle_in = 232 *angle_mid = 233 *angle_out = FT_Atan2( d3.x, d3.y ); 234 } 235 } 236 else /* !close2 */ 237 { 238 if ( close3 ) 239 { 240 *angle_in = 241 *angle_mid = 242 *angle_out = FT_Atan2( d2.x, d2.y ); 243 } 244 else /* !close3 */ 245 { 246 *angle_in = 247 *angle_mid = FT_Atan2( d2.x, d2.y ); 248 *angle_out = FT_Atan2( d3.x, d3.y ); 249 } 250 } 251 } 252 else /* !close1 */ 253 { 254 if ( close2 ) 255 { 256 if ( close3 ) 257 { 258 *angle_in = 259 *angle_mid = 260 *angle_out = FT_Atan2( d1.x, d1.y ); 261 } 262 else /* !close3 */ 263 { 264 *angle_in = FT_Atan2( d1.x, d1.y ); 265 *angle_out = FT_Atan2( d3.x, d3.y ); 266 *angle_mid = ft_angle_mean( *angle_in, *angle_out ); 267 } 268 } 269 else /* !close2 */ 270 { 271 if ( close3 ) 272 { 273 *angle_in = FT_Atan2( d1.x, d1.y ); 274 *angle_mid = 275 *angle_out = FT_Atan2( d2.x, d2.y ); 276 } 277 else /* !close3 */ 278 { 279 *angle_in = FT_Atan2( d1.x, d1.y ); 280 *angle_mid = FT_Atan2( d2.x, d2.y ); 281 *angle_out = FT_Atan2( d3.x, d3.y ); 282 } 283 } 284 } 285 286 theta1 = ft_pos_abs( FT_Angle_Diff( *angle_in, *angle_mid ) ); 287 theta2 = ft_pos_abs( FT_Angle_Diff( *angle_mid, *angle_out ) ); 288 289 return FT_BOOL( theta1 < FT_SMALL_CUBIC_THRESHOLD && 290 theta2 < FT_SMALL_CUBIC_THRESHOLD ); 291 } 292 293 294 /*************************************************************************/ 295 /*************************************************************************/ 296 /***** *****/ 297 /***** STROKE BORDERS *****/ 298 /***** *****/ 299 /*************************************************************************/ 300 /*************************************************************************/ 301 302 typedef enum FT_StrokeTags_ 303 { 304 FT_STROKE_TAG_ON = 1, /* on-curve point */ 305 FT_STROKE_TAG_CUBIC = 2, /* cubic off-point */ 306 FT_STROKE_TAG_BEGIN = 4, /* sub-path start */ 307 FT_STROKE_TAG_END = 8 /* sub-path end */ 308 309 } FT_StrokeTags; 310 311 #define FT_STROKE_TAG_BEGIN_END ( FT_STROKE_TAG_BEGIN | FT_STROKE_TAG_END ) 312 313 typedef struct FT_StrokeBorderRec_ 314 { 315 FT_UInt num_points; 316 FT_UInt max_points; 317 FT_Vector* points; 318 FT_Byte* tags; 319 FT_Bool movable; /* TRUE for ends of lineto borders */ 320 FT_Int start; /* index of current sub-path start point */ 321 FT_Memory memory; 322 FT_Bool valid; 323 324 } FT_StrokeBorderRec, *FT_StrokeBorder; 325 326 327 static FT_Error ft_stroke_border_grow(FT_StrokeBorder border,FT_UInt new_points)328 ft_stroke_border_grow( FT_StrokeBorder border, 329 FT_UInt new_points ) 330 { 331 FT_UInt old_max = border->max_points; 332 FT_UInt new_max = border->num_points + new_points; 333 FT_Error error = FT_Err_Ok; 334 335 336 if ( new_max > old_max ) 337 { 338 FT_UInt cur_max = old_max; 339 FT_Memory memory = border->memory; 340 341 342 while ( cur_max < new_max ) 343 cur_max += ( cur_max >> 1 ) + 16; 344 345 if ( FT_RENEW_ARRAY( border->points, old_max, cur_max ) || 346 FT_RENEW_ARRAY( border->tags, old_max, cur_max ) ) 347 goto Exit; 348 349 border->max_points = cur_max; 350 } 351 352 Exit: 353 return error; 354 } 355 356 357 static void ft_stroke_border_close(FT_StrokeBorder border,FT_Bool reverse)358 ft_stroke_border_close( FT_StrokeBorder border, 359 FT_Bool reverse ) 360 { 361 FT_UInt start = (FT_UInt)border->start; 362 FT_UInt count = border->num_points; 363 364 365 FT_ASSERT( border->start >= 0 ); 366 367 /* don't record empty paths! */ 368 if ( count <= start + 1U ) 369 border->num_points = start; 370 else 371 { 372 /* copy the last point to the start of this sub-path, since */ 373 /* it contains the `adjusted' starting coordinates */ 374 border->num_points = --count; 375 border->points[start] = border->points[count]; 376 border->tags[start] = border->tags[count]; 377 378 if ( reverse ) 379 { 380 /* reverse the points */ 381 { 382 FT_Vector* vec1 = border->points + start + 1; 383 FT_Vector* vec2 = border->points + count - 1; 384 385 386 for ( ; vec1 < vec2; vec1++, vec2-- ) 387 { 388 FT_Vector tmp; 389 390 391 tmp = *vec1; 392 *vec1 = *vec2; 393 *vec2 = tmp; 394 } 395 } 396 397 /* then the tags */ 398 { 399 FT_Byte* tag1 = border->tags + start + 1; 400 FT_Byte* tag2 = border->tags + count - 1; 401 402 403 for ( ; tag1 < tag2; tag1++, tag2-- ) 404 { 405 FT_Byte tmp; 406 407 408 tmp = *tag1; 409 *tag1 = *tag2; 410 *tag2 = tmp; 411 } 412 } 413 } 414 415 border->tags[start ] |= FT_STROKE_TAG_BEGIN; 416 border->tags[count - 1] |= FT_STROKE_TAG_END; 417 } 418 419 border->start = -1; 420 border->movable = FALSE; 421 } 422 423 424 static FT_Error ft_stroke_border_lineto(FT_StrokeBorder border,FT_Vector * to,FT_Bool movable)425 ft_stroke_border_lineto( FT_StrokeBorder border, 426 FT_Vector* to, 427 FT_Bool movable ) 428 { 429 FT_Error error = FT_Err_Ok; 430 431 432 FT_ASSERT( border->start >= 0 ); 433 434 if ( border->movable ) 435 { 436 /* move last point */ 437 border->points[border->num_points - 1] = *to; 438 } 439 else 440 { 441 /* don't add zero-length lineto, but always add moveto */ 442 if ( border->num_points > (FT_UInt)border->start && 443 FT_IS_SMALL( border->points[border->num_points - 1].x - to->x ) && 444 FT_IS_SMALL( border->points[border->num_points - 1].y - to->y ) ) 445 return error; 446 447 /* add one point */ 448 error = ft_stroke_border_grow( border, 1 ); 449 if ( !error ) 450 { 451 FT_Vector* vec = border->points + border->num_points; 452 FT_Byte* tag = border->tags + border->num_points; 453 454 455 vec[0] = *to; 456 tag[0] = FT_STROKE_TAG_ON; 457 458 border->num_points += 1; 459 } 460 } 461 border->movable = movable; 462 return error; 463 } 464 465 466 static FT_Error ft_stroke_border_conicto(FT_StrokeBorder border,FT_Vector * control,FT_Vector * to)467 ft_stroke_border_conicto( FT_StrokeBorder border, 468 FT_Vector* control, 469 FT_Vector* to ) 470 { 471 FT_Error error; 472 473 474 FT_ASSERT( border->start >= 0 ); 475 476 error = ft_stroke_border_grow( border, 2 ); 477 if ( !error ) 478 { 479 FT_Vector* vec = border->points + border->num_points; 480 FT_Byte* tag = border->tags + border->num_points; 481 482 483 vec[0] = *control; 484 vec[1] = *to; 485 486 tag[0] = 0; 487 tag[1] = FT_STROKE_TAG_ON; 488 489 border->num_points += 2; 490 } 491 492 border->movable = FALSE; 493 494 return error; 495 } 496 497 498 static FT_Error ft_stroke_border_cubicto(FT_StrokeBorder border,FT_Vector * control1,FT_Vector * control2,FT_Vector * to)499 ft_stroke_border_cubicto( FT_StrokeBorder border, 500 FT_Vector* control1, 501 FT_Vector* control2, 502 FT_Vector* to ) 503 { 504 FT_Error error; 505 506 507 FT_ASSERT( border->start >= 0 ); 508 509 error = ft_stroke_border_grow( border, 3 ); 510 if ( !error ) 511 { 512 FT_Vector* vec = border->points + border->num_points; 513 FT_Byte* tag = border->tags + border->num_points; 514 515 516 vec[0] = *control1; 517 vec[1] = *control2; 518 vec[2] = *to; 519 520 tag[0] = FT_STROKE_TAG_CUBIC; 521 tag[1] = FT_STROKE_TAG_CUBIC; 522 tag[2] = FT_STROKE_TAG_ON; 523 524 border->num_points += 3; 525 } 526 527 border->movable = FALSE; 528 529 return error; 530 } 531 532 533 #define FT_ARC_CUBIC_ANGLE ( FT_ANGLE_PI / 2 ) 534 535 536 static FT_Error ft_stroke_border_arcto(FT_StrokeBorder border,FT_Vector * center,FT_Fixed radius,FT_Angle angle_start,FT_Angle angle_diff)537 ft_stroke_border_arcto( FT_StrokeBorder border, 538 FT_Vector* center, 539 FT_Fixed radius, 540 FT_Angle angle_start, 541 FT_Angle angle_diff ) 542 { 543 FT_Fixed coef; 544 FT_Vector a0, a1, a2, a3; 545 FT_Int i, arcs = 1; 546 FT_Error error = FT_Err_Ok; 547 548 549 /* number of cubic arcs to draw */ 550 while ( angle_diff > FT_ARC_CUBIC_ANGLE * arcs || 551 -angle_diff > FT_ARC_CUBIC_ANGLE * arcs ) 552 arcs++; 553 554 /* control tangents */ 555 coef = FT_Tan( angle_diff / ( 4 * arcs ) ); 556 coef += coef / 3; 557 558 /* compute start and first control point */ 559 FT_Vector_From_Polar( &a0, radius, angle_start ); 560 a1.x = FT_MulFix( -a0.y, coef ); 561 a1.y = FT_MulFix( a0.x, coef ); 562 563 a0.x += center->x; 564 a0.y += center->y; 565 a1.x += a0.x; 566 a1.y += a0.y; 567 568 for ( i = 1; i <= arcs; i++ ) 569 { 570 /* compute end and second control point */ 571 FT_Vector_From_Polar( &a3, radius, 572 angle_start + i * angle_diff / arcs ); 573 a2.x = FT_MulFix( a3.y, coef ); 574 a2.y = FT_MulFix( -a3.x, coef ); 575 576 a3.x += center->x; 577 a3.y += center->y; 578 a2.x += a3.x; 579 a2.y += a3.y; 580 581 /* add cubic arc */ 582 error = ft_stroke_border_cubicto( border, &a1, &a2, &a3 ); 583 if ( error ) 584 break; 585 586 /* a0 = a3; */ 587 a1.x = a3.x - a2.x + a3.x; 588 a1.y = a3.y - a2.y + a3.y; 589 } 590 591 return error; 592 } 593 594 595 static FT_Error ft_stroke_border_moveto(FT_StrokeBorder border,FT_Vector * to)596 ft_stroke_border_moveto( FT_StrokeBorder border, 597 FT_Vector* to ) 598 { 599 /* close current open path if any ? */ 600 if ( border->start >= 0 ) 601 ft_stroke_border_close( border, FALSE ); 602 603 border->start = (FT_Int)border->num_points; 604 border->movable = FALSE; 605 606 return ft_stroke_border_lineto( border, to, FALSE ); 607 } 608 609 610 static void ft_stroke_border_init(FT_StrokeBorder border,FT_Memory memory)611 ft_stroke_border_init( FT_StrokeBorder border, 612 FT_Memory memory ) 613 { 614 border->memory = memory; 615 border->points = NULL; 616 border->tags = NULL; 617 618 border->num_points = 0; 619 border->max_points = 0; 620 border->start = -1; 621 border->valid = FALSE; 622 } 623 624 625 static void ft_stroke_border_reset(FT_StrokeBorder border)626 ft_stroke_border_reset( FT_StrokeBorder border ) 627 { 628 border->num_points = 0; 629 border->start = -1; 630 border->valid = FALSE; 631 } 632 633 634 static void ft_stroke_border_done(FT_StrokeBorder border)635 ft_stroke_border_done( FT_StrokeBorder border ) 636 { 637 FT_Memory memory = border->memory; 638 639 640 FT_FREE( border->points ); 641 FT_FREE( border->tags ); 642 643 border->num_points = 0; 644 border->max_points = 0; 645 border->start = -1; 646 border->valid = FALSE; 647 } 648 649 650 static FT_Error ft_stroke_border_get_counts(FT_StrokeBorder border,FT_UInt * anum_points,FT_UInt * anum_contours)651 ft_stroke_border_get_counts( FT_StrokeBorder border, 652 FT_UInt *anum_points, 653 FT_UInt *anum_contours ) 654 { 655 FT_Error error = FT_Err_Ok; 656 FT_UInt num_points = 0; 657 FT_UInt num_contours = 0; 658 659 FT_UInt count = border->num_points; 660 FT_Vector* point = border->points; 661 FT_Byte* tags = border->tags; 662 FT_Int in_contour = 0; 663 664 665 for ( ; count > 0; count--, num_points++, point++, tags++ ) 666 { 667 if ( tags[0] & FT_STROKE_TAG_BEGIN ) 668 { 669 if ( in_contour != 0 ) 670 goto Fail; 671 672 in_contour = 1; 673 } 674 else if ( in_contour == 0 ) 675 goto Fail; 676 677 if ( tags[0] & FT_STROKE_TAG_END ) 678 { 679 in_contour = 0; 680 num_contours++; 681 } 682 } 683 684 if ( in_contour != 0 ) 685 goto Fail; 686 687 border->valid = TRUE; 688 689 Exit: 690 *anum_points = num_points; 691 *anum_contours = num_contours; 692 return error; 693 694 Fail: 695 num_points = 0; 696 num_contours = 0; 697 goto Exit; 698 } 699 700 701 static void ft_stroke_border_export(FT_StrokeBorder border,FT_Outline * outline)702 ft_stroke_border_export( FT_StrokeBorder border, 703 FT_Outline* outline ) 704 { 705 /* copy point locations */ 706 if ( border->num_points ) 707 FT_ARRAY_COPY( outline->points + outline->n_points, 708 border->points, 709 border->num_points ); 710 711 /* copy tags */ 712 { 713 FT_UInt count = border->num_points; 714 FT_Byte* read = border->tags; 715 FT_Byte* write = (FT_Byte*)outline->tags + outline->n_points; 716 717 718 for ( ; count > 0; count--, read++, write++ ) 719 { 720 if ( *read & FT_STROKE_TAG_ON ) 721 *write = FT_CURVE_TAG_ON; 722 else if ( *read & FT_STROKE_TAG_CUBIC ) 723 *write = FT_CURVE_TAG_CUBIC; 724 else 725 *write = FT_CURVE_TAG_CONIC; 726 } 727 } 728 729 /* copy contours */ 730 { 731 FT_UInt count = border->num_points; 732 FT_Byte* tags = border->tags; 733 FT_Short* write = outline->contours + outline->n_contours; 734 FT_Short idx = (FT_Short)outline->n_points; 735 736 737 for ( ; count > 0; count--, tags++, idx++ ) 738 { 739 if ( *tags & FT_STROKE_TAG_END ) 740 { 741 *write++ = idx; 742 outline->n_contours++; 743 } 744 } 745 } 746 747 outline->n_points += (short)border->num_points; 748 749 FT_ASSERT( FT_Outline_Check( outline ) == 0 ); 750 } 751 752 753 /*************************************************************************/ 754 /*************************************************************************/ 755 /***** *****/ 756 /***** STROKER *****/ 757 /***** *****/ 758 /*************************************************************************/ 759 /*************************************************************************/ 760 761 #define FT_SIDE_TO_ROTATE( s ) ( FT_ANGLE_PI2 - (s) * FT_ANGLE_PI ) 762 763 typedef struct FT_StrokerRec_ 764 { 765 FT_Angle angle_in; /* direction into curr join */ 766 FT_Angle angle_out; /* direction out of join */ 767 FT_Vector center; /* current position */ 768 FT_Fixed line_length; /* length of last lineto */ 769 FT_Bool first_point; /* is this the start? */ 770 FT_Bool subpath_open; /* is the subpath open? */ 771 FT_Angle subpath_angle; /* subpath start direction */ 772 FT_Vector subpath_start; /* subpath start position */ 773 FT_Fixed subpath_line_length; /* subpath start lineto len */ 774 FT_Bool handle_wide_strokes; /* use wide strokes logic? */ 775 776 FT_Stroker_LineCap line_cap; 777 FT_Stroker_LineJoin line_join; 778 FT_Stroker_LineJoin line_join_saved; 779 FT_Fixed miter_limit; 780 FT_Fixed radius; 781 782 FT_StrokeBorderRec borders[2]; 783 FT_Library library; 784 785 } FT_StrokerRec; 786 787 788 /* documentation is in ftstroke.h */ 789 790 FT_EXPORT_DEF( FT_Error ) FT_Stroker_New(FT_Library library,FT_Stroker * astroker)791 FT_Stroker_New( FT_Library library, 792 FT_Stroker *astroker ) 793 { 794 FT_Error error; /* assigned in FT_NEW */ 795 FT_Memory memory; 796 FT_Stroker stroker = NULL; 797 798 799 if ( !library ) 800 return FT_THROW( Invalid_Library_Handle ); 801 802 if ( !astroker ) 803 return FT_THROW( Invalid_Argument ); 804 805 memory = library->memory; 806 807 if ( !FT_NEW( stroker ) ) 808 { 809 stroker->library = library; 810 811 ft_stroke_border_init( &stroker->borders[0], memory ); 812 ft_stroke_border_init( &stroker->borders[1], memory ); 813 } 814 815 *astroker = stroker; 816 817 return error; 818 } 819 820 821 /* documentation is in ftstroke.h */ 822 823 FT_EXPORT_DEF( void ) FT_Stroker_Set(FT_Stroker stroker,FT_Fixed radius,FT_Stroker_LineCap line_cap,FT_Stroker_LineJoin line_join,FT_Fixed miter_limit)824 FT_Stroker_Set( FT_Stroker stroker, 825 FT_Fixed radius, 826 FT_Stroker_LineCap line_cap, 827 FT_Stroker_LineJoin line_join, 828 FT_Fixed miter_limit ) 829 { 830 if ( !stroker ) 831 return; 832 833 stroker->radius = radius; 834 stroker->line_cap = line_cap; 835 stroker->line_join = line_join; 836 stroker->miter_limit = miter_limit; 837 838 /* ensure miter limit has sensible value */ 839 if ( stroker->miter_limit < 0x10000L ) 840 stroker->miter_limit = 0x10000L; 841 842 /* save line join style: */ 843 /* line join style can be temporarily changed when stroking curves */ 844 stroker->line_join_saved = line_join; 845 846 FT_Stroker_Rewind( stroker ); 847 } 848 849 850 /* documentation is in ftstroke.h */ 851 852 FT_EXPORT_DEF( void ) FT_Stroker_Rewind(FT_Stroker stroker)853 FT_Stroker_Rewind( FT_Stroker stroker ) 854 { 855 if ( stroker ) 856 { 857 ft_stroke_border_reset( &stroker->borders[0] ); 858 ft_stroke_border_reset( &stroker->borders[1] ); 859 } 860 } 861 862 863 /* documentation is in ftstroke.h */ 864 865 FT_EXPORT_DEF( void ) FT_Stroker_Done(FT_Stroker stroker)866 FT_Stroker_Done( FT_Stroker stroker ) 867 { 868 if ( stroker ) 869 { 870 FT_Memory memory = stroker->library->memory; 871 872 873 ft_stroke_border_done( &stroker->borders[0] ); 874 ft_stroke_border_done( &stroker->borders[1] ); 875 876 stroker->library = NULL; 877 FT_FREE( stroker ); 878 } 879 } 880 881 882 /* create a circular arc at a corner or cap */ 883 static FT_Error ft_stroker_arcto(FT_Stroker stroker,FT_Int side)884 ft_stroker_arcto( FT_Stroker stroker, 885 FT_Int side ) 886 { 887 FT_Angle total, rotate; 888 FT_Fixed radius = stroker->radius; 889 FT_Error error = FT_Err_Ok; 890 FT_StrokeBorder border = stroker->borders + side; 891 892 893 rotate = FT_SIDE_TO_ROTATE( side ); 894 895 total = FT_Angle_Diff( stroker->angle_in, stroker->angle_out ); 896 if ( total == FT_ANGLE_PI ) 897 total = -rotate * 2; 898 899 error = ft_stroke_border_arcto( border, 900 &stroker->center, 901 radius, 902 stroker->angle_in + rotate, 903 total ); 904 border->movable = FALSE; 905 return error; 906 } 907 908 909 /* add a cap at the end of an opened path */ 910 static FT_Error ft_stroker_cap(FT_Stroker stroker,FT_Angle angle,FT_Int side)911 ft_stroker_cap( FT_Stroker stroker, 912 FT_Angle angle, 913 FT_Int side ) 914 { 915 FT_Error error = FT_Err_Ok; 916 917 918 if ( stroker->line_cap == FT_STROKER_LINECAP_ROUND ) 919 { 920 /* add a round cap */ 921 stroker->angle_in = angle; 922 stroker->angle_out = angle + FT_ANGLE_PI; 923 924 error = ft_stroker_arcto( stroker, side ); 925 } 926 else 927 { 928 /* add a square or butt cap */ 929 FT_Vector middle, delta; 930 FT_Fixed radius = stroker->radius; 931 FT_StrokeBorder border = stroker->borders + side; 932 933 934 /* compute middle point and first angle point */ 935 FT_Vector_From_Polar( &middle, radius, angle ); 936 delta.x = side ? middle.y : -middle.y; 937 delta.y = side ? -middle.x : middle.x; 938 939 if ( stroker->line_cap == FT_STROKER_LINECAP_SQUARE ) 940 { 941 middle.x += stroker->center.x; 942 middle.y += stroker->center.y; 943 } 944 else /* FT_STROKER_LINECAP_BUTT */ 945 { 946 middle.x = stroker->center.x; 947 middle.y = stroker->center.y; 948 } 949 950 delta.x += middle.x; 951 delta.y += middle.y; 952 953 error = ft_stroke_border_lineto( border, &delta, FALSE ); 954 if ( error ) 955 goto Exit; 956 957 /* compute second angle point */ 958 delta.x = middle.x - delta.x + middle.x; 959 delta.y = middle.y - delta.y + middle.y; 960 961 error = ft_stroke_border_lineto( border, &delta, FALSE ); 962 } 963 964 Exit: 965 return error; 966 } 967 968 969 /* process an inside corner, i.e. compute intersection */ 970 static FT_Error ft_stroker_inside(FT_Stroker stroker,FT_Int side,FT_Fixed line_length)971 ft_stroker_inside( FT_Stroker stroker, 972 FT_Int side, 973 FT_Fixed line_length ) 974 { 975 FT_StrokeBorder border = stroker->borders + side; 976 FT_Angle phi, theta, rotate; 977 FT_Fixed length; 978 FT_Vector sigma, delta; 979 FT_Error error = FT_Err_Ok; 980 FT_Bool intersect; /* use intersection of lines? */ 981 982 983 rotate = FT_SIDE_TO_ROTATE( side ); 984 985 theta = FT_Angle_Diff( stroker->angle_in, stroker->angle_out ) / 2; 986 987 /* Only intersect borders if between two lineto's and both */ 988 /* lines are long enough (line_length is zero for curves). */ 989 /* Also avoid U-turns of nearly 180 degree. */ 990 if ( !border->movable || line_length == 0 || 991 theta > 0x59C000 || theta < -0x59C000 ) 992 intersect = FALSE; 993 else 994 { 995 /* compute minimum required length of lines */ 996 FT_Fixed min_length; 997 998 999 FT_Vector_Unit( &sigma, theta ); 1000 min_length = 1001 ft_pos_abs( FT_MulDiv( stroker->radius, sigma.y, sigma.x ) ); 1002 1003 intersect = FT_BOOL( min_length && 1004 stroker->line_length >= min_length && 1005 line_length >= min_length ); 1006 } 1007 1008 if ( !intersect ) 1009 { 1010 FT_Vector_From_Polar( &delta, stroker->radius, 1011 stroker->angle_out + rotate ); 1012 delta.x += stroker->center.x; 1013 delta.y += stroker->center.y; 1014 1015 border->movable = FALSE; 1016 } 1017 else 1018 { 1019 /* compute median angle */ 1020 phi = stroker->angle_in + theta + rotate; 1021 1022 length = FT_DivFix( stroker->radius, sigma.x ); 1023 1024 FT_Vector_From_Polar( &delta, length, phi ); 1025 delta.x += stroker->center.x; 1026 delta.y += stroker->center.y; 1027 } 1028 1029 error = ft_stroke_border_lineto( border, &delta, FALSE ); 1030 1031 return error; 1032 } 1033 1034 1035 /* process an outside corner, i.e. compute bevel/miter/round */ 1036 static FT_Error ft_stroker_outside(FT_Stroker stroker,FT_Int side,FT_Fixed line_length)1037 ft_stroker_outside( FT_Stroker stroker, 1038 FT_Int side, 1039 FT_Fixed line_length ) 1040 { 1041 FT_StrokeBorder border = stroker->borders + side; 1042 FT_Error error; 1043 FT_Angle rotate; 1044 1045 1046 if ( stroker->line_join == FT_STROKER_LINEJOIN_ROUND ) 1047 error = ft_stroker_arcto( stroker, side ); 1048 else 1049 { 1050 /* this is a mitered (pointed) or beveled (truncated) corner */ 1051 FT_Fixed radius = stroker->radius; 1052 FT_Vector sigma; 1053 FT_Angle theta = 0, phi = 0; 1054 FT_Bool bevel, fixed_bevel; 1055 1056 1057 rotate = FT_SIDE_TO_ROTATE( side ); 1058 1059 bevel = 1060 FT_BOOL( stroker->line_join == FT_STROKER_LINEJOIN_BEVEL ); 1061 1062 fixed_bevel = 1063 FT_BOOL( stroker->line_join != FT_STROKER_LINEJOIN_MITER_VARIABLE ); 1064 1065 /* check miter limit first */ 1066 if ( !bevel ) 1067 { 1068 theta = FT_Angle_Diff( stroker->angle_in, stroker->angle_out ) / 2; 1069 1070 if ( theta == FT_ANGLE_PI2 ) 1071 theta = -rotate; 1072 1073 phi = stroker->angle_in + theta + rotate; 1074 1075 FT_Vector_From_Polar( &sigma, stroker->miter_limit, theta ); 1076 1077 /* is miter limit exceeded? */ 1078 if ( sigma.x < 0x10000L ) 1079 { 1080 /* don't create variable bevels for very small deviations; */ 1081 /* FT_Sin(x) = 0 for x <= 57 */ 1082 if ( fixed_bevel || ft_pos_abs( theta ) > 57 ) 1083 bevel = TRUE; 1084 } 1085 } 1086 1087 if ( bevel ) /* this is a bevel (broken angle) */ 1088 { 1089 if ( fixed_bevel ) 1090 { 1091 /* the outer corners are simply joined together */ 1092 FT_Vector delta; 1093 1094 1095 /* add bevel */ 1096 FT_Vector_From_Polar( &delta, 1097 radius, 1098 stroker->angle_out + rotate ); 1099 delta.x += stroker->center.x; 1100 delta.y += stroker->center.y; 1101 1102 border->movable = FALSE; 1103 error = ft_stroke_border_lineto( border, &delta, FALSE ); 1104 } 1105 else /* variable bevel or clipped miter */ 1106 { 1107 /* the miter is truncated */ 1108 FT_Vector middle, delta; 1109 FT_Fixed coef; 1110 1111 1112 /* compute middle point and first angle point */ 1113 FT_Vector_From_Polar( &middle, 1114 FT_MulFix( radius, stroker->miter_limit ), 1115 phi ); 1116 1117 coef = FT_DivFix( 0x10000L - sigma.x, sigma.y ); 1118 delta.x = FT_MulFix( middle.y, coef ); 1119 delta.y = FT_MulFix( -middle.x, coef ); 1120 1121 middle.x += stroker->center.x; 1122 middle.y += stroker->center.y; 1123 delta.x += middle.x; 1124 delta.y += middle.y; 1125 1126 error = ft_stroke_border_lineto( border, &delta, FALSE ); 1127 if ( error ) 1128 goto Exit; 1129 1130 /* compute second angle point */ 1131 delta.x = middle.x - delta.x + middle.x; 1132 delta.y = middle.y - delta.y + middle.y; 1133 1134 error = ft_stroke_border_lineto( border, &delta, FALSE ); 1135 if ( error ) 1136 goto Exit; 1137 1138 /* finally, add an end point; only needed if not lineto */ 1139 /* (line_length is zero for curves) */ 1140 if ( line_length == 0 ) 1141 { 1142 FT_Vector_From_Polar( &delta, 1143 radius, 1144 stroker->angle_out + rotate ); 1145 1146 delta.x += stroker->center.x; 1147 delta.y += stroker->center.y; 1148 1149 error = ft_stroke_border_lineto( border, &delta, FALSE ); 1150 } 1151 } 1152 } 1153 else /* this is a miter (intersection) */ 1154 { 1155 FT_Fixed length; 1156 FT_Vector delta; 1157 1158 1159 length = FT_MulDiv( stroker->radius, stroker->miter_limit, sigma.x ); 1160 1161 FT_Vector_From_Polar( &delta, length, phi ); 1162 delta.x += stroker->center.x; 1163 delta.y += stroker->center.y; 1164 1165 error = ft_stroke_border_lineto( border, &delta, FALSE ); 1166 if ( error ) 1167 goto Exit; 1168 1169 /* now add an end point; only needed if not lineto */ 1170 /* (line_length is zero for curves) */ 1171 if ( line_length == 0 ) 1172 { 1173 FT_Vector_From_Polar( &delta, 1174 stroker->radius, 1175 stroker->angle_out + rotate ); 1176 delta.x += stroker->center.x; 1177 delta.y += stroker->center.y; 1178 1179 error = ft_stroke_border_lineto( border, &delta, FALSE ); 1180 } 1181 } 1182 } 1183 1184 Exit: 1185 return error; 1186 } 1187 1188 1189 static FT_Error ft_stroker_process_corner(FT_Stroker stroker,FT_Fixed line_length)1190 ft_stroker_process_corner( FT_Stroker stroker, 1191 FT_Fixed line_length ) 1192 { 1193 FT_Error error = FT_Err_Ok; 1194 FT_Angle turn; 1195 FT_Int inside_side; 1196 1197 1198 turn = FT_Angle_Diff( stroker->angle_in, stroker->angle_out ); 1199 1200 /* no specific corner processing is required if the turn is 0 */ 1201 if ( turn == 0 ) 1202 goto Exit; 1203 1204 /* when we turn to the right, the inside side is 0 */ 1205 /* otherwise, the inside side is 1 */ 1206 inside_side = ( turn < 0 ); 1207 1208 /* process the inside side */ 1209 error = ft_stroker_inside( stroker, inside_side, line_length ); 1210 if ( error ) 1211 goto Exit; 1212 1213 /* process the outside side */ 1214 error = ft_stroker_outside( stroker, !inside_side, line_length ); 1215 1216 Exit: 1217 return error; 1218 } 1219 1220 1221 /* add two points to the left and right borders corresponding to the */ 1222 /* start of the subpath */ 1223 static FT_Error ft_stroker_subpath_start(FT_Stroker stroker,FT_Angle start_angle,FT_Fixed line_length)1224 ft_stroker_subpath_start( FT_Stroker stroker, 1225 FT_Angle start_angle, 1226 FT_Fixed line_length ) 1227 { 1228 FT_Vector delta; 1229 FT_Vector point; 1230 FT_Error error; 1231 FT_StrokeBorder border; 1232 1233 1234 FT_Vector_From_Polar( &delta, stroker->radius, 1235 start_angle + FT_ANGLE_PI2 ); 1236 1237 point.x = stroker->center.x + delta.x; 1238 point.y = stroker->center.y + delta.y; 1239 1240 border = stroker->borders; 1241 error = ft_stroke_border_moveto( border, &point ); 1242 if ( error ) 1243 goto Exit; 1244 1245 point.x = stroker->center.x - delta.x; 1246 point.y = stroker->center.y - delta.y; 1247 1248 border++; 1249 error = ft_stroke_border_moveto( border, &point ); 1250 1251 /* save angle, position, and line length for last join */ 1252 /* (line_length is zero for curves) */ 1253 stroker->subpath_angle = start_angle; 1254 stroker->first_point = FALSE; 1255 stroker->subpath_line_length = line_length; 1256 1257 Exit: 1258 return error; 1259 } 1260 1261 1262 /* documentation is in ftstroke.h */ 1263 1264 FT_EXPORT_DEF( FT_Error ) FT_Stroker_LineTo(FT_Stroker stroker,FT_Vector * to)1265 FT_Stroker_LineTo( FT_Stroker stroker, 1266 FT_Vector* to ) 1267 { 1268 FT_Error error = FT_Err_Ok; 1269 FT_StrokeBorder border; 1270 FT_Vector delta; 1271 FT_Angle angle; 1272 FT_Int side; 1273 FT_Fixed line_length; 1274 1275 1276 if ( !stroker || !to ) 1277 return FT_THROW( Invalid_Argument ); 1278 1279 delta.x = to->x - stroker->center.x; 1280 delta.y = to->y - stroker->center.y; 1281 1282 /* a zero-length lineto is a no-op; avoid creating a spurious corner */ 1283 if ( delta.x == 0 && delta.y == 0 ) 1284 goto Exit; 1285 1286 /* compute length of line */ 1287 line_length = FT_Vector_Length( &delta ); 1288 1289 angle = FT_Atan2( delta.x, delta.y ); 1290 FT_Vector_From_Polar( &delta, stroker->radius, angle + FT_ANGLE_PI2 ); 1291 1292 /* process corner if necessary */ 1293 if ( stroker->first_point ) 1294 { 1295 /* This is the first segment of a subpath. We need to */ 1296 /* add a point to each border at their respective starting */ 1297 /* point locations. */ 1298 error = ft_stroker_subpath_start( stroker, angle, line_length ); 1299 if ( error ) 1300 goto Exit; 1301 } 1302 else 1303 { 1304 /* process the current corner */ 1305 stroker->angle_out = angle; 1306 error = ft_stroker_process_corner( stroker, line_length ); 1307 if ( error ) 1308 goto Exit; 1309 } 1310 1311 /* now add a line segment to both the `inside' and `outside' paths */ 1312 for ( border = stroker->borders, side = 1; side >= 0; side--, border++ ) 1313 { 1314 FT_Vector point; 1315 1316 1317 point.x = to->x + delta.x; 1318 point.y = to->y + delta.y; 1319 1320 /* the ends of lineto borders are movable */ 1321 error = ft_stroke_border_lineto( border, &point, TRUE ); 1322 if ( error ) 1323 goto Exit; 1324 1325 delta.x = -delta.x; 1326 delta.y = -delta.y; 1327 } 1328 1329 stroker->angle_in = angle; 1330 stroker->center = *to; 1331 stroker->line_length = line_length; 1332 1333 Exit: 1334 return error; 1335 } 1336 1337 1338 /* documentation is in ftstroke.h */ 1339 1340 FT_EXPORT_DEF( FT_Error ) FT_Stroker_ConicTo(FT_Stroker stroker,FT_Vector * control,FT_Vector * to)1341 FT_Stroker_ConicTo( FT_Stroker stroker, 1342 FT_Vector* control, 1343 FT_Vector* to ) 1344 { 1345 FT_Error error = FT_Err_Ok; 1346 FT_Vector bez_stack[34]; 1347 FT_Vector* arc; 1348 FT_Vector* limit = bez_stack + 30; 1349 FT_Bool first_arc = TRUE; 1350 1351 1352 if ( !stroker || !control || !to ) 1353 { 1354 error = FT_THROW( Invalid_Argument ); 1355 goto Exit; 1356 } 1357 1358 /* if all control points are coincident, this is a no-op; */ 1359 /* avoid creating a spurious corner */ 1360 if ( FT_IS_SMALL( stroker->center.x - control->x ) && 1361 FT_IS_SMALL( stroker->center.y - control->y ) && 1362 FT_IS_SMALL( control->x - to->x ) && 1363 FT_IS_SMALL( control->y - to->y ) ) 1364 { 1365 stroker->center = *to; 1366 goto Exit; 1367 } 1368 1369 arc = bez_stack; 1370 arc[0] = *to; 1371 arc[1] = *control; 1372 arc[2] = stroker->center; 1373 1374 while ( arc >= bez_stack ) 1375 { 1376 FT_Angle angle_in, angle_out; 1377 1378 1379 /* initialize with current direction */ 1380 angle_in = angle_out = stroker->angle_in; 1381 1382 if ( arc < limit && 1383 !ft_conic_is_small_enough( arc, &angle_in, &angle_out ) ) 1384 { 1385 if ( stroker->first_point ) 1386 stroker->angle_in = angle_in; 1387 1388 ft_conic_split( arc ); 1389 arc += 2; 1390 continue; 1391 } 1392 1393 if ( first_arc ) 1394 { 1395 first_arc = FALSE; 1396 1397 /* process corner if necessary */ 1398 if ( stroker->first_point ) 1399 error = ft_stroker_subpath_start( stroker, angle_in, 0 ); 1400 else 1401 { 1402 stroker->angle_out = angle_in; 1403 error = ft_stroker_process_corner( stroker, 0 ); 1404 } 1405 } 1406 else if ( ft_pos_abs( FT_Angle_Diff( stroker->angle_in, angle_in ) ) > 1407 FT_SMALL_CONIC_THRESHOLD / 4 ) 1408 { 1409 /* if the deviation from one arc to the next is too great, */ 1410 /* add a round corner */ 1411 stroker->center = arc[2]; 1412 stroker->angle_out = angle_in; 1413 stroker->line_join = FT_STROKER_LINEJOIN_ROUND; 1414 1415 error = ft_stroker_process_corner( stroker, 0 ); 1416 1417 /* reinstate line join style */ 1418 stroker->line_join = stroker->line_join_saved; 1419 } 1420 1421 if ( error ) 1422 goto Exit; 1423 1424 /* the arc's angle is small enough; we can add it directly to each */ 1425 /* border */ 1426 { 1427 FT_Vector ctrl, end; 1428 FT_Angle theta, phi, rotate, alpha0 = 0; 1429 FT_Fixed length; 1430 FT_StrokeBorder border; 1431 FT_Int side; 1432 1433 1434 theta = FT_Angle_Diff( angle_in, angle_out ) / 2; 1435 phi = angle_in + theta; 1436 length = FT_DivFix( stroker->radius, FT_Cos( theta ) ); 1437 1438 /* compute direction of original arc */ 1439 if ( stroker->handle_wide_strokes ) 1440 alpha0 = FT_Atan2( arc[0].x - arc[2].x, arc[0].y - arc[2].y ); 1441 1442 for ( border = stroker->borders, side = 0; 1443 side <= 1; 1444 side++, border++ ) 1445 { 1446 rotate = FT_SIDE_TO_ROTATE( side ); 1447 1448 /* compute control point */ 1449 FT_Vector_From_Polar( &ctrl, length, phi + rotate ); 1450 ctrl.x += arc[1].x; 1451 ctrl.y += arc[1].y; 1452 1453 /* compute end point */ 1454 FT_Vector_From_Polar( &end, stroker->radius, angle_out + rotate ); 1455 end.x += arc[0].x; 1456 end.y += arc[0].y; 1457 1458 if ( stroker->handle_wide_strokes ) 1459 { 1460 FT_Vector start; 1461 FT_Angle alpha1; 1462 1463 1464 /* determine whether the border radius is greater than the */ 1465 /* radius of curvature of the original arc */ 1466 start = border->points[border->num_points - 1]; 1467 1468 alpha1 = FT_Atan2( end.x - start.x, end.y - start.y ); 1469 1470 /* is the direction of the border arc opposite to */ 1471 /* that of the original arc? */ 1472 if ( ft_pos_abs( FT_Angle_Diff( alpha0, alpha1 ) ) > 1473 FT_ANGLE_PI / 2 ) 1474 { 1475 FT_Angle beta, gamma; 1476 FT_Vector bvec, delta; 1477 FT_Fixed blen, sinA, sinB, alen; 1478 1479 1480 /* use the sine rule to find the intersection point */ 1481 beta = FT_Atan2( arc[2].x - start.x, arc[2].y - start.y ); 1482 gamma = FT_Atan2( arc[0].x - end.x, arc[0].y - end.y ); 1483 1484 bvec.x = end.x - start.x; 1485 bvec.y = end.y - start.y; 1486 1487 blen = FT_Vector_Length( &bvec ); 1488 1489 sinA = ft_pos_abs( FT_Sin( alpha1 - gamma ) ); 1490 sinB = ft_pos_abs( FT_Sin( beta - gamma ) ); 1491 1492 alen = FT_MulDiv( blen, sinA, sinB ); 1493 1494 FT_Vector_From_Polar( &delta, alen, beta ); 1495 delta.x += start.x; 1496 delta.y += start.y; 1497 1498 /* circumnavigate the negative sector backwards */ 1499 border->movable = FALSE; 1500 error = ft_stroke_border_lineto( border, &delta, FALSE ); 1501 if ( error ) 1502 goto Exit; 1503 error = ft_stroke_border_lineto( border, &end, FALSE ); 1504 if ( error ) 1505 goto Exit; 1506 error = ft_stroke_border_conicto( border, &ctrl, &start ); 1507 if ( error ) 1508 goto Exit; 1509 /* and then move to the endpoint */ 1510 error = ft_stroke_border_lineto( border, &end, FALSE ); 1511 if ( error ) 1512 goto Exit; 1513 1514 continue; 1515 } 1516 1517 /* else fall through */ 1518 } 1519 1520 /* simply add an arc */ 1521 error = ft_stroke_border_conicto( border, &ctrl, &end ); 1522 if ( error ) 1523 goto Exit; 1524 } 1525 } 1526 1527 arc -= 2; 1528 1529 stroker->angle_in = angle_out; 1530 } 1531 1532 stroker->center = *to; 1533 1534 Exit: 1535 return error; 1536 } 1537 1538 1539 /* documentation is in ftstroke.h */ 1540 1541 FT_EXPORT_DEF( FT_Error ) FT_Stroker_CubicTo(FT_Stroker stroker,FT_Vector * control1,FT_Vector * control2,FT_Vector * to)1542 FT_Stroker_CubicTo( FT_Stroker stroker, 1543 FT_Vector* control1, 1544 FT_Vector* control2, 1545 FT_Vector* to ) 1546 { 1547 FT_Error error = FT_Err_Ok; 1548 FT_Vector bez_stack[37]; 1549 FT_Vector* arc; 1550 FT_Vector* limit = bez_stack + 32; 1551 FT_Bool first_arc = TRUE; 1552 1553 1554 if ( !stroker || !control1 || !control2 || !to ) 1555 { 1556 error = FT_THROW( Invalid_Argument ); 1557 goto Exit; 1558 } 1559 1560 /* if all control points are coincident, this is a no-op; */ 1561 /* avoid creating a spurious corner */ 1562 if ( FT_IS_SMALL( stroker->center.x - control1->x ) && 1563 FT_IS_SMALL( stroker->center.y - control1->y ) && 1564 FT_IS_SMALL( control1->x - control2->x ) && 1565 FT_IS_SMALL( control1->y - control2->y ) && 1566 FT_IS_SMALL( control2->x - to->x ) && 1567 FT_IS_SMALL( control2->y - to->y ) ) 1568 { 1569 stroker->center = *to; 1570 goto Exit; 1571 } 1572 1573 arc = bez_stack; 1574 arc[0] = *to; 1575 arc[1] = *control2; 1576 arc[2] = *control1; 1577 arc[3] = stroker->center; 1578 1579 while ( arc >= bez_stack ) 1580 { 1581 FT_Angle angle_in, angle_mid, angle_out; 1582 1583 1584 /* initialize with current direction */ 1585 angle_in = angle_out = angle_mid = stroker->angle_in; 1586 1587 if ( arc < limit && 1588 !ft_cubic_is_small_enough( arc, &angle_in, 1589 &angle_mid, &angle_out ) ) 1590 { 1591 if ( stroker->first_point ) 1592 stroker->angle_in = angle_in; 1593 1594 ft_cubic_split( arc ); 1595 arc += 3; 1596 continue; 1597 } 1598 1599 if ( first_arc ) 1600 { 1601 first_arc = FALSE; 1602 1603 /* process corner if necessary */ 1604 if ( stroker->first_point ) 1605 error = ft_stroker_subpath_start( stroker, angle_in, 0 ); 1606 else 1607 { 1608 stroker->angle_out = angle_in; 1609 error = ft_stroker_process_corner( stroker, 0 ); 1610 } 1611 } 1612 else if ( ft_pos_abs( FT_Angle_Diff( stroker->angle_in, angle_in ) ) > 1613 FT_SMALL_CUBIC_THRESHOLD / 4 ) 1614 { 1615 /* if the deviation from one arc to the next is too great, */ 1616 /* add a round corner */ 1617 stroker->center = arc[3]; 1618 stroker->angle_out = angle_in; 1619 stroker->line_join = FT_STROKER_LINEJOIN_ROUND; 1620 1621 error = ft_stroker_process_corner( stroker, 0 ); 1622 1623 /* reinstate line join style */ 1624 stroker->line_join = stroker->line_join_saved; 1625 } 1626 1627 if ( error ) 1628 goto Exit; 1629 1630 /* the arc's angle is small enough; we can add it directly to each */ 1631 /* border */ 1632 { 1633 FT_Vector ctrl1, ctrl2, end; 1634 FT_Angle theta1, phi1, theta2, phi2, rotate, alpha0 = 0; 1635 FT_Fixed length1, length2; 1636 FT_StrokeBorder border; 1637 FT_Int side; 1638 1639 1640 theta1 = FT_Angle_Diff( angle_in, angle_mid ) / 2; 1641 theta2 = FT_Angle_Diff( angle_mid, angle_out ) / 2; 1642 phi1 = ft_angle_mean( angle_in, angle_mid ); 1643 phi2 = ft_angle_mean( angle_mid, angle_out ); 1644 length1 = FT_DivFix( stroker->radius, FT_Cos( theta1 ) ); 1645 length2 = FT_DivFix( stroker->radius, FT_Cos( theta2 ) ); 1646 1647 /* compute direction of original arc */ 1648 if ( stroker->handle_wide_strokes ) 1649 alpha0 = FT_Atan2( arc[0].x - arc[3].x, arc[0].y - arc[3].y ); 1650 1651 for ( border = stroker->borders, side = 0; 1652 side <= 1; 1653 side++, border++ ) 1654 { 1655 rotate = FT_SIDE_TO_ROTATE( side ); 1656 1657 /* compute control points */ 1658 FT_Vector_From_Polar( &ctrl1, length1, phi1 + rotate ); 1659 ctrl1.x += arc[2].x; 1660 ctrl1.y += arc[2].y; 1661 1662 FT_Vector_From_Polar( &ctrl2, length2, phi2 + rotate ); 1663 ctrl2.x += arc[1].x; 1664 ctrl2.y += arc[1].y; 1665 1666 /* compute end point */ 1667 FT_Vector_From_Polar( &end, stroker->radius, angle_out + rotate ); 1668 end.x += arc[0].x; 1669 end.y += arc[0].y; 1670 1671 if ( stroker->handle_wide_strokes ) 1672 { 1673 FT_Vector start; 1674 FT_Angle alpha1; 1675 1676 1677 /* determine whether the border radius is greater than the */ 1678 /* radius of curvature of the original arc */ 1679 start = border->points[border->num_points - 1]; 1680 1681 alpha1 = FT_Atan2( end.x - start.x, end.y - start.y ); 1682 1683 /* is the direction of the border arc opposite to */ 1684 /* that of the original arc? */ 1685 if ( ft_pos_abs( FT_Angle_Diff( alpha0, alpha1 ) ) > 1686 FT_ANGLE_PI / 2 ) 1687 { 1688 FT_Angle beta, gamma; 1689 FT_Vector bvec, delta; 1690 FT_Fixed blen, sinA, sinB, alen; 1691 1692 1693 /* use the sine rule to find the intersection point */ 1694 beta = FT_Atan2( arc[3].x - start.x, arc[3].y - start.y ); 1695 gamma = FT_Atan2( arc[0].x - end.x, arc[0].y - end.y ); 1696 1697 bvec.x = end.x - start.x; 1698 bvec.y = end.y - start.y; 1699 1700 blen = FT_Vector_Length( &bvec ); 1701 1702 sinA = ft_pos_abs( FT_Sin( alpha1 - gamma ) ); 1703 sinB = ft_pos_abs( FT_Sin( beta - gamma ) ); 1704 1705 alen = FT_MulDiv( blen, sinA, sinB ); 1706 1707 FT_Vector_From_Polar( &delta, alen, beta ); 1708 delta.x += start.x; 1709 delta.y += start.y; 1710 1711 /* circumnavigate the negative sector backwards */ 1712 border->movable = FALSE; 1713 error = ft_stroke_border_lineto( border, &delta, FALSE ); 1714 if ( error ) 1715 goto Exit; 1716 error = ft_stroke_border_lineto( border, &end, FALSE ); 1717 if ( error ) 1718 goto Exit; 1719 error = ft_stroke_border_cubicto( border, 1720 &ctrl2, 1721 &ctrl1, 1722 &start ); 1723 if ( error ) 1724 goto Exit; 1725 /* and then move to the endpoint */ 1726 error = ft_stroke_border_lineto( border, &end, FALSE ); 1727 if ( error ) 1728 goto Exit; 1729 1730 continue; 1731 } 1732 1733 /* else fall through */ 1734 } 1735 1736 /* simply add an arc */ 1737 error = ft_stroke_border_cubicto( border, &ctrl1, &ctrl2, &end ); 1738 if ( error ) 1739 goto Exit; 1740 } 1741 } 1742 1743 arc -= 3; 1744 1745 stroker->angle_in = angle_out; 1746 } 1747 1748 stroker->center = *to; 1749 1750 Exit: 1751 return error; 1752 } 1753 1754 1755 /* documentation is in ftstroke.h */ 1756 1757 FT_EXPORT_DEF( FT_Error ) FT_Stroker_BeginSubPath(FT_Stroker stroker,FT_Vector * to,FT_Bool open)1758 FT_Stroker_BeginSubPath( FT_Stroker stroker, 1759 FT_Vector* to, 1760 FT_Bool open ) 1761 { 1762 if ( !stroker || !to ) 1763 return FT_THROW( Invalid_Argument ); 1764 1765 /* We cannot process the first point, because there is not enough */ 1766 /* information regarding its corner/cap. The latter will be processed */ 1767 /* in the `FT_Stroker_EndSubPath' routine. */ 1768 /* */ 1769 stroker->first_point = TRUE; 1770 stroker->center = *to; 1771 stroker->subpath_open = open; 1772 1773 /* Determine if we need to check whether the border radius is greater */ 1774 /* than the radius of curvature of a curve, to handle this case */ 1775 /* specially. This is only required if bevel joins or butt caps may */ 1776 /* be created, because round & miter joins and round & square caps */ 1777 /* cover the negative sector created with wide strokes. */ 1778 stroker->handle_wide_strokes = 1779 FT_BOOL( stroker->line_join != FT_STROKER_LINEJOIN_ROUND || 1780 ( stroker->subpath_open && 1781 stroker->line_cap == FT_STROKER_LINECAP_BUTT ) ); 1782 1783 /* record the subpath start point for each border */ 1784 stroker->subpath_start = *to; 1785 1786 stroker->angle_in = 0; 1787 1788 return FT_Err_Ok; 1789 } 1790 1791 1792 static FT_Error ft_stroker_add_reverse_left(FT_Stroker stroker,FT_Bool open)1793 ft_stroker_add_reverse_left( FT_Stroker stroker, 1794 FT_Bool open ) 1795 { 1796 FT_StrokeBorder right = stroker->borders + 0; 1797 FT_StrokeBorder left = stroker->borders + 1; 1798 FT_Int new_points; 1799 FT_Error error = FT_Err_Ok; 1800 1801 1802 FT_ASSERT( left->start >= 0 ); 1803 1804 new_points = (FT_Int)left->num_points - left->start; 1805 if ( new_points > 0 ) 1806 { 1807 error = ft_stroke_border_grow( right, (FT_UInt)new_points ); 1808 if ( error ) 1809 goto Exit; 1810 1811 { 1812 FT_Vector* dst_point = right->points + right->num_points; 1813 FT_Byte* dst_tag = right->tags + right->num_points; 1814 FT_Vector* src_point = left->points + left->num_points - 1; 1815 FT_Byte* src_tag = left->tags + left->num_points - 1; 1816 1817 1818 while ( src_point >= left->points + left->start ) 1819 { 1820 *dst_point = *src_point; 1821 *dst_tag = *src_tag; 1822 1823 if ( open ) 1824 dst_tag[0] &= ~FT_STROKE_TAG_BEGIN_END; 1825 else 1826 { 1827 FT_Byte ttag = 1828 (FT_Byte)( dst_tag[0] & FT_STROKE_TAG_BEGIN_END ); 1829 1830 1831 /* switch begin/end tags if necessary */ 1832 if ( ttag == FT_STROKE_TAG_BEGIN || 1833 ttag == FT_STROKE_TAG_END ) 1834 dst_tag[0] ^= FT_STROKE_TAG_BEGIN_END; 1835 } 1836 1837 src_point--; 1838 src_tag--; 1839 dst_point++; 1840 dst_tag++; 1841 } 1842 } 1843 1844 left->num_points = (FT_UInt)left->start; 1845 right->num_points += (FT_UInt)new_points; 1846 1847 right->movable = FALSE; 1848 left->movable = FALSE; 1849 } 1850 1851 Exit: 1852 return error; 1853 } 1854 1855 1856 /* documentation is in ftstroke.h */ 1857 1858 /* there's a lot of magic in this function! */ 1859 FT_EXPORT_DEF( FT_Error ) FT_Stroker_EndSubPath(FT_Stroker stroker)1860 FT_Stroker_EndSubPath( FT_Stroker stroker ) 1861 { 1862 FT_Error error = FT_Err_Ok; 1863 1864 1865 if ( !stroker ) 1866 { 1867 error = FT_THROW( Invalid_Argument ); 1868 goto Exit; 1869 } 1870 1871 if ( stroker->subpath_open ) 1872 { 1873 FT_StrokeBorder right = stroker->borders; 1874 1875 1876 /* All right, this is an opened path, we need to add a cap between */ 1877 /* right & left, add the reverse of left, then add a final cap */ 1878 /* between left & right. */ 1879 error = ft_stroker_cap( stroker, stroker->angle_in, 0 ); 1880 if ( error ) 1881 goto Exit; 1882 1883 /* add reversed points from `left' to `right' */ 1884 error = ft_stroker_add_reverse_left( stroker, TRUE ); 1885 if ( error ) 1886 goto Exit; 1887 1888 /* now add the final cap */ 1889 stroker->center = stroker->subpath_start; 1890 error = ft_stroker_cap( stroker, 1891 stroker->subpath_angle + FT_ANGLE_PI, 0 ); 1892 if ( error ) 1893 goto Exit; 1894 1895 /* Now end the right subpath accordingly. The left one is */ 1896 /* rewind and doesn't need further processing. */ 1897 ft_stroke_border_close( right, FALSE ); 1898 } 1899 else 1900 { 1901 FT_Angle turn; 1902 FT_Int inside_side; 1903 1904 1905 /* close the path if needed */ 1906 if ( stroker->center.x != stroker->subpath_start.x || 1907 stroker->center.y != stroker->subpath_start.y ) 1908 { 1909 error = FT_Stroker_LineTo( stroker, &stroker->subpath_start ); 1910 if ( error ) 1911 goto Exit; 1912 } 1913 1914 /* process the corner */ 1915 stroker->angle_out = stroker->subpath_angle; 1916 turn = FT_Angle_Diff( stroker->angle_in, 1917 stroker->angle_out ); 1918 1919 /* no specific corner processing is required if the turn is 0 */ 1920 if ( turn != 0 ) 1921 { 1922 /* when we turn to the right, the inside side is 0 */ 1923 /* otherwise, the inside side is 1 */ 1924 inside_side = ( turn < 0 ); 1925 1926 error = ft_stroker_inside( stroker, 1927 inside_side, 1928 stroker->subpath_line_length ); 1929 if ( error ) 1930 goto Exit; 1931 1932 /* process the outside side */ 1933 error = ft_stroker_outside( stroker, 1934 !inside_side, 1935 stroker->subpath_line_length ); 1936 if ( error ) 1937 goto Exit; 1938 } 1939 1940 /* then end our two subpaths */ 1941 ft_stroke_border_close( stroker->borders + 0, FALSE ); 1942 ft_stroke_border_close( stroker->borders + 1, TRUE ); 1943 } 1944 1945 Exit: 1946 return error; 1947 } 1948 1949 1950 /* documentation is in ftstroke.h */ 1951 1952 FT_EXPORT_DEF( FT_Error ) FT_Stroker_GetBorderCounts(FT_Stroker stroker,FT_StrokerBorder border,FT_UInt * anum_points,FT_UInt * anum_contours)1953 FT_Stroker_GetBorderCounts( FT_Stroker stroker, 1954 FT_StrokerBorder border, 1955 FT_UInt *anum_points, 1956 FT_UInt *anum_contours ) 1957 { 1958 FT_UInt num_points = 0, num_contours = 0; 1959 FT_Error error; 1960 1961 1962 if ( !stroker || border > 1 ) 1963 { 1964 error = FT_THROW( Invalid_Argument ); 1965 goto Exit; 1966 } 1967 1968 error = ft_stroke_border_get_counts( stroker->borders + border, 1969 &num_points, &num_contours ); 1970 Exit: 1971 if ( anum_points ) 1972 *anum_points = num_points; 1973 1974 if ( anum_contours ) 1975 *anum_contours = num_contours; 1976 1977 return error; 1978 } 1979 1980 1981 /* documentation is in ftstroke.h */ 1982 1983 FT_EXPORT_DEF( FT_Error ) FT_Stroker_GetCounts(FT_Stroker stroker,FT_UInt * anum_points,FT_UInt * anum_contours)1984 FT_Stroker_GetCounts( FT_Stroker stroker, 1985 FT_UInt *anum_points, 1986 FT_UInt *anum_contours ) 1987 { 1988 FT_UInt count1, count2, num_points = 0; 1989 FT_UInt count3, count4, num_contours = 0; 1990 FT_Error error; 1991 1992 1993 if ( !stroker ) 1994 { 1995 error = FT_THROW( Invalid_Argument ); 1996 goto Exit; 1997 } 1998 1999 error = ft_stroke_border_get_counts( stroker->borders + 0, 2000 &count1, &count2 ); 2001 if ( error ) 2002 goto Exit; 2003 2004 error = ft_stroke_border_get_counts( stroker->borders + 1, 2005 &count3, &count4 ); 2006 if ( error ) 2007 goto Exit; 2008 2009 num_points = count1 + count3; 2010 num_contours = count2 + count4; 2011 2012 Exit: 2013 if ( anum_points ) 2014 *anum_points = num_points; 2015 2016 if ( anum_contours ) 2017 *anum_contours = num_contours; 2018 2019 return error; 2020 } 2021 2022 2023 /* documentation is in ftstroke.h */ 2024 2025 FT_EXPORT_DEF( void ) FT_Stroker_ExportBorder(FT_Stroker stroker,FT_StrokerBorder border,FT_Outline * outline)2026 FT_Stroker_ExportBorder( FT_Stroker stroker, 2027 FT_StrokerBorder border, 2028 FT_Outline* outline ) 2029 { 2030 if ( !stroker || !outline ) 2031 return; 2032 2033 if ( border == FT_STROKER_BORDER_LEFT || 2034 border == FT_STROKER_BORDER_RIGHT ) 2035 { 2036 FT_StrokeBorder sborder = & stroker->borders[border]; 2037 2038 2039 if ( sborder->valid ) 2040 ft_stroke_border_export( sborder, outline ); 2041 } 2042 } 2043 2044 2045 /* documentation is in ftstroke.h */ 2046 2047 FT_EXPORT_DEF( void ) FT_Stroker_Export(FT_Stroker stroker,FT_Outline * outline)2048 FT_Stroker_Export( FT_Stroker stroker, 2049 FT_Outline* outline ) 2050 { 2051 FT_Stroker_ExportBorder( stroker, FT_STROKER_BORDER_LEFT, outline ); 2052 FT_Stroker_ExportBorder( stroker, FT_STROKER_BORDER_RIGHT, outline ); 2053 } 2054 2055 2056 /* documentation is in ftstroke.h */ 2057 2058 /* 2059 * The following is very similar to FT_Outline_Decompose, except 2060 * that we do support opened paths, and do not scale the outline. 2061 */ 2062 FT_EXPORT_DEF( FT_Error ) FT_Stroker_ParseOutline(FT_Stroker stroker,FT_Outline * outline,FT_Bool opened)2063 FT_Stroker_ParseOutline( FT_Stroker stroker, 2064 FT_Outline* outline, 2065 FT_Bool opened ) 2066 { 2067 FT_Vector v_last; 2068 FT_Vector v_control; 2069 FT_Vector v_start; 2070 2071 FT_Vector* point; 2072 FT_Vector* limit; 2073 char* tags; 2074 2075 FT_Error error; 2076 2077 FT_Int n; /* index of contour in outline */ 2078 FT_UInt first; /* index of first point in contour */ 2079 FT_Int tag; /* current point's state */ 2080 2081 2082 if ( !outline ) 2083 return FT_THROW( Invalid_Outline ); 2084 2085 if ( !stroker ) 2086 return FT_THROW( Invalid_Argument ); 2087 2088 FT_Stroker_Rewind( stroker ); 2089 2090 first = 0; 2091 2092 for ( n = 0; n < outline->n_contours; n++ ) 2093 { 2094 FT_UInt last; /* index of last point in contour */ 2095 2096 2097 last = (FT_UInt)outline->contours[n]; 2098 limit = outline->points + last; 2099 2100 /* skip empty points; we don't stroke these */ 2101 if ( last <= first ) 2102 { 2103 first = last + 1; 2104 continue; 2105 } 2106 2107 v_start = outline->points[first]; 2108 v_last = outline->points[last]; 2109 2110 v_control = v_start; 2111 2112 point = outline->points + first; 2113 tags = outline->tags + first; 2114 tag = FT_CURVE_TAG( tags[0] ); 2115 2116 /* A contour cannot start with a cubic control point! */ 2117 if ( tag == FT_CURVE_TAG_CUBIC ) 2118 goto Invalid_Outline; 2119 2120 /* check first point to determine origin */ 2121 if ( tag == FT_CURVE_TAG_CONIC ) 2122 { 2123 /* First point is conic control. Yes, this happens. */ 2124 if ( FT_CURVE_TAG( outline->tags[last] ) == FT_CURVE_TAG_ON ) 2125 { 2126 /* start at last point if it is on the curve */ 2127 v_start = v_last; 2128 limit--; 2129 } 2130 else 2131 { 2132 /* if both first and last points are conic, */ 2133 /* start at their middle */ 2134 v_start.x = ( v_start.x + v_last.x ) / 2; 2135 v_start.y = ( v_start.y + v_last.y ) / 2; 2136 } 2137 point--; 2138 tags--; 2139 } 2140 2141 error = FT_Stroker_BeginSubPath( stroker, &v_start, opened ); 2142 if ( error ) 2143 goto Exit; 2144 2145 while ( point < limit ) 2146 { 2147 point++; 2148 tags++; 2149 2150 tag = FT_CURVE_TAG( tags[0] ); 2151 switch ( tag ) 2152 { 2153 case FT_CURVE_TAG_ON: /* emit a single line_to */ 2154 { 2155 FT_Vector vec; 2156 2157 2158 vec.x = point->x; 2159 vec.y = point->y; 2160 2161 error = FT_Stroker_LineTo( stroker, &vec ); 2162 if ( error ) 2163 goto Exit; 2164 continue; 2165 } 2166 2167 case FT_CURVE_TAG_CONIC: /* consume conic arcs */ 2168 v_control.x = point->x; 2169 v_control.y = point->y; 2170 2171 Do_Conic: 2172 if ( point < limit ) 2173 { 2174 FT_Vector vec; 2175 FT_Vector v_middle; 2176 2177 2178 point++; 2179 tags++; 2180 tag = FT_CURVE_TAG( tags[0] ); 2181 2182 vec = point[0]; 2183 2184 if ( tag == FT_CURVE_TAG_ON ) 2185 { 2186 error = FT_Stroker_ConicTo( stroker, &v_control, &vec ); 2187 if ( error ) 2188 goto Exit; 2189 continue; 2190 } 2191 2192 if ( tag != FT_CURVE_TAG_CONIC ) 2193 goto Invalid_Outline; 2194 2195 v_middle.x = ( v_control.x + vec.x ) / 2; 2196 v_middle.y = ( v_control.y + vec.y ) / 2; 2197 2198 error = FT_Stroker_ConicTo( stroker, &v_control, &v_middle ); 2199 if ( error ) 2200 goto Exit; 2201 2202 v_control = vec; 2203 goto Do_Conic; 2204 } 2205 2206 error = FT_Stroker_ConicTo( stroker, &v_control, &v_start ); 2207 goto Close; 2208 2209 default: /* FT_CURVE_TAG_CUBIC */ 2210 { 2211 FT_Vector vec1, vec2; 2212 2213 2214 if ( point + 1 > limit || 2215 FT_CURVE_TAG( tags[1] ) != FT_CURVE_TAG_CUBIC ) 2216 goto Invalid_Outline; 2217 2218 point += 2; 2219 tags += 2; 2220 2221 vec1 = point[-2]; 2222 vec2 = point[-1]; 2223 2224 if ( point <= limit ) 2225 { 2226 FT_Vector vec; 2227 2228 2229 vec = point[0]; 2230 2231 error = FT_Stroker_CubicTo( stroker, &vec1, &vec2, &vec ); 2232 if ( error ) 2233 goto Exit; 2234 continue; 2235 } 2236 2237 error = FT_Stroker_CubicTo( stroker, &vec1, &vec2, &v_start ); 2238 goto Close; 2239 } 2240 } 2241 } 2242 2243 Close: 2244 if ( error ) 2245 goto Exit; 2246 2247 /* don't try to end the path if no segments have been generated */ 2248 if ( !stroker->first_point ) 2249 { 2250 error = FT_Stroker_EndSubPath( stroker ); 2251 if ( error ) 2252 goto Exit; 2253 } 2254 2255 first = last + 1; 2256 } 2257 2258 return FT_Err_Ok; 2259 2260 Exit: 2261 return error; 2262 2263 Invalid_Outline: 2264 return FT_THROW( Invalid_Outline ); 2265 } 2266 2267 2268 /* documentation is in ftstroke.h */ 2269 2270 FT_EXPORT_DEF( FT_Error ) FT_Glyph_Stroke(FT_Glyph * pglyph,FT_Stroker stroker,FT_Bool destroy)2271 FT_Glyph_Stroke( FT_Glyph *pglyph, 2272 FT_Stroker stroker, 2273 FT_Bool destroy ) 2274 { 2275 FT_Error error = FT_ERR( Invalid_Argument ); 2276 FT_Glyph glyph = NULL; 2277 2278 2279 if ( !pglyph ) 2280 goto Exit; 2281 2282 glyph = *pglyph; 2283 if ( !glyph || glyph->clazz != &ft_outline_glyph_class ) 2284 goto Exit; 2285 2286 { 2287 FT_Glyph copy; 2288 2289 2290 error = FT_Glyph_Copy( glyph, © ); 2291 if ( error ) 2292 goto Exit; 2293 2294 glyph = copy; 2295 } 2296 2297 { 2298 FT_OutlineGlyph oglyph = (FT_OutlineGlyph)glyph; 2299 FT_Outline* outline = &oglyph->outline; 2300 FT_UInt num_points, num_contours; 2301 2302 2303 error = FT_Stroker_ParseOutline( stroker, outline, FALSE ); 2304 if ( error ) 2305 goto Fail; 2306 2307 FT_Stroker_GetCounts( stroker, &num_points, &num_contours ); 2308 2309 FT_Outline_Done( glyph->library, outline ); 2310 2311 error = FT_Outline_New( glyph->library, 2312 num_points, 2313 (FT_Int)num_contours, 2314 outline ); 2315 if ( error ) 2316 goto Fail; 2317 2318 outline->n_points = 0; 2319 outline->n_contours = 0; 2320 2321 FT_Stroker_Export( stroker, outline ); 2322 } 2323 2324 if ( destroy ) 2325 FT_Done_Glyph( *pglyph ); 2326 2327 *pglyph = glyph; 2328 goto Exit; 2329 2330 Fail: 2331 FT_Done_Glyph( glyph ); 2332 glyph = NULL; 2333 2334 if ( !destroy ) 2335 *pglyph = NULL; 2336 2337 Exit: 2338 return error; 2339 } 2340 2341 2342 /* documentation is in ftstroke.h */ 2343 2344 FT_EXPORT_DEF( FT_Error ) FT_Glyph_StrokeBorder(FT_Glyph * pglyph,FT_Stroker stroker,FT_Bool inside,FT_Bool destroy)2345 FT_Glyph_StrokeBorder( FT_Glyph *pglyph, 2346 FT_Stroker stroker, 2347 FT_Bool inside, 2348 FT_Bool destroy ) 2349 { 2350 FT_Error error = FT_ERR( Invalid_Argument ); 2351 FT_Glyph glyph = NULL; 2352 2353 2354 if ( !pglyph ) 2355 goto Exit; 2356 2357 glyph = *pglyph; 2358 if ( !glyph || glyph->clazz != &ft_outline_glyph_class ) 2359 goto Exit; 2360 2361 { 2362 FT_Glyph copy; 2363 2364 2365 error = FT_Glyph_Copy( glyph, © ); 2366 if ( error ) 2367 goto Exit; 2368 2369 glyph = copy; 2370 } 2371 2372 { 2373 FT_OutlineGlyph oglyph = (FT_OutlineGlyph)glyph; 2374 FT_StrokerBorder border; 2375 FT_Outline* outline = &oglyph->outline; 2376 FT_UInt num_points, num_contours; 2377 2378 2379 border = FT_Outline_GetOutsideBorder( outline ); 2380 if ( inside ) 2381 { 2382 if ( border == FT_STROKER_BORDER_LEFT ) 2383 border = FT_STROKER_BORDER_RIGHT; 2384 else 2385 border = FT_STROKER_BORDER_LEFT; 2386 } 2387 2388 error = FT_Stroker_ParseOutline( stroker, outline, FALSE ); 2389 if ( error ) 2390 goto Fail; 2391 2392 FT_Stroker_GetBorderCounts( stroker, border, 2393 &num_points, &num_contours ); 2394 2395 FT_Outline_Done( glyph->library, outline ); 2396 2397 error = FT_Outline_New( glyph->library, 2398 num_points, 2399 (FT_Int)num_contours, 2400 outline ); 2401 if ( error ) 2402 goto Fail; 2403 2404 outline->n_points = 0; 2405 outline->n_contours = 0; 2406 2407 FT_Stroker_ExportBorder( stroker, border, outline ); 2408 } 2409 2410 if ( destroy ) 2411 FT_Done_Glyph( *pglyph ); 2412 2413 *pglyph = glyph; 2414 goto Exit; 2415 2416 Fail: 2417 FT_Done_Glyph( glyph ); 2418 glyph = NULL; 2419 2420 if ( !destroy ) 2421 *pglyph = NULL; 2422 2423 Exit: 2424 return error; 2425 } 2426 2427 2428 /* END */ 2429