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 ) 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_Angle total, angle, step, rotate, next, theta; 544 FT_Vector a, b, a2, b2; 545 FT_Fixed length; 546 FT_Error error = FT_Err_Ok; 547 548 549 /* compute start point */ 550 FT_Vector_From_Polar( &a, radius, angle_start ); 551 a.x += center->x; 552 a.y += center->y; 553 554 total = angle_diff; 555 angle = angle_start; 556 rotate = ( angle_diff >= 0 ) ? FT_ANGLE_PI2 : -FT_ANGLE_PI2; 557 558 while ( total != 0 ) 559 { 560 step = total; 561 if ( step > FT_ARC_CUBIC_ANGLE ) 562 step = FT_ARC_CUBIC_ANGLE; 563 564 else if ( step < -FT_ARC_CUBIC_ANGLE ) 565 step = -FT_ARC_CUBIC_ANGLE; 566 567 next = angle + step; 568 theta = step; 569 if ( theta < 0 ) 570 theta = -theta; 571 572 theta >>= 1; 573 574 /* compute end point */ 575 FT_Vector_From_Polar( &b, radius, next ); 576 b.x += center->x; 577 b.y += center->y; 578 579 /* compute first and second control points */ 580 length = FT_MulDiv( radius, FT_Sin( theta ) * 4, 581 ( 0x10000L + FT_Cos( theta ) ) * 3 ); 582 583 FT_Vector_From_Polar( &a2, length, angle + rotate ); 584 a2.x += a.x; 585 a2.y += a.y; 586 587 FT_Vector_From_Polar( &b2, length, next - rotate ); 588 b2.x += b.x; 589 b2.y += b.y; 590 591 /* add cubic arc */ 592 error = ft_stroke_border_cubicto( border, &a2, &b2, &b ); 593 if ( error ) 594 break; 595 596 /* process the rest of the arc ?? */ 597 a = b; 598 total -= step; 599 angle = next; 600 } 601 602 return error; 603 } 604 605 606 static FT_Error ft_stroke_border_moveto(FT_StrokeBorder border,FT_Vector * to)607 ft_stroke_border_moveto( FT_StrokeBorder border, 608 FT_Vector* to ) 609 { 610 /* close current open path if any ? */ 611 if ( border->start >= 0 ) 612 ft_stroke_border_close( border, FALSE ); 613 614 border->start = (FT_Int)border->num_points; 615 border->movable = FALSE; 616 617 return ft_stroke_border_lineto( border, to, FALSE ); 618 } 619 620 621 static void ft_stroke_border_init(FT_StrokeBorder border,FT_Memory memory)622 ft_stroke_border_init( FT_StrokeBorder border, 623 FT_Memory memory ) 624 { 625 border->memory = memory; 626 border->points = NULL; 627 border->tags = NULL; 628 629 border->num_points = 0; 630 border->max_points = 0; 631 border->start = -1; 632 border->valid = FALSE; 633 } 634 635 636 static void ft_stroke_border_reset(FT_StrokeBorder border)637 ft_stroke_border_reset( FT_StrokeBorder border ) 638 { 639 border->num_points = 0; 640 border->start = -1; 641 border->valid = FALSE; 642 } 643 644 645 static void ft_stroke_border_done(FT_StrokeBorder border)646 ft_stroke_border_done( FT_StrokeBorder border ) 647 { 648 FT_Memory memory = border->memory; 649 650 651 FT_FREE( border->points ); 652 FT_FREE( border->tags ); 653 654 border->num_points = 0; 655 border->max_points = 0; 656 border->start = -1; 657 border->valid = FALSE; 658 } 659 660 661 static FT_Error ft_stroke_border_get_counts(FT_StrokeBorder border,FT_UInt * anum_points,FT_UInt * anum_contours)662 ft_stroke_border_get_counts( FT_StrokeBorder border, 663 FT_UInt *anum_points, 664 FT_UInt *anum_contours ) 665 { 666 FT_Error error = FT_Err_Ok; 667 FT_UInt num_points = 0; 668 FT_UInt num_contours = 0; 669 670 FT_UInt count = border->num_points; 671 FT_Vector* point = border->points; 672 FT_Byte* tags = border->tags; 673 FT_Int in_contour = 0; 674 675 676 for ( ; count > 0; count--, num_points++, point++, tags++ ) 677 { 678 if ( tags[0] & FT_STROKE_TAG_BEGIN ) 679 { 680 if ( in_contour != 0 ) 681 goto Fail; 682 683 in_contour = 1; 684 } 685 else if ( in_contour == 0 ) 686 goto Fail; 687 688 if ( tags[0] & FT_STROKE_TAG_END ) 689 { 690 in_contour = 0; 691 num_contours++; 692 } 693 } 694 695 if ( in_contour != 0 ) 696 goto Fail; 697 698 border->valid = TRUE; 699 700 Exit: 701 *anum_points = num_points; 702 *anum_contours = num_contours; 703 return error; 704 705 Fail: 706 num_points = 0; 707 num_contours = 0; 708 goto Exit; 709 } 710 711 712 static void ft_stroke_border_export(FT_StrokeBorder border,FT_Outline * outline)713 ft_stroke_border_export( FT_StrokeBorder border, 714 FT_Outline* outline ) 715 { 716 /* copy point locations */ 717 if ( border->num_points ) 718 FT_ARRAY_COPY( outline->points + outline->n_points, 719 border->points, 720 border->num_points ); 721 722 /* copy tags */ 723 { 724 FT_UInt count = border->num_points; 725 FT_Byte* read = border->tags; 726 FT_Byte* write = (FT_Byte*)outline->tags + outline->n_points; 727 728 729 for ( ; count > 0; count--, read++, write++ ) 730 { 731 if ( *read & FT_STROKE_TAG_ON ) 732 *write = FT_CURVE_TAG_ON; 733 else if ( *read & FT_STROKE_TAG_CUBIC ) 734 *write = FT_CURVE_TAG_CUBIC; 735 else 736 *write = FT_CURVE_TAG_CONIC; 737 } 738 } 739 740 /* copy contours */ 741 { 742 FT_UInt count = border->num_points; 743 FT_Byte* tags = border->tags; 744 FT_Short* write = outline->contours + outline->n_contours; 745 FT_Short idx = (FT_Short)outline->n_points; 746 747 748 for ( ; count > 0; count--, tags++, idx++ ) 749 { 750 if ( *tags & FT_STROKE_TAG_END ) 751 { 752 *write++ = idx; 753 outline->n_contours++; 754 } 755 } 756 } 757 758 outline->n_points += (short)border->num_points; 759 760 FT_ASSERT( FT_Outline_Check( outline ) == 0 ); 761 } 762 763 764 /*************************************************************************/ 765 /*************************************************************************/ 766 /***** *****/ 767 /***** STROKER *****/ 768 /***** *****/ 769 /*************************************************************************/ 770 /*************************************************************************/ 771 772 #define FT_SIDE_TO_ROTATE( s ) ( FT_ANGLE_PI2 - (s) * FT_ANGLE_PI ) 773 774 typedef struct FT_StrokerRec_ 775 { 776 FT_Angle angle_in; /* direction into curr join */ 777 FT_Angle angle_out; /* direction out of join */ 778 FT_Vector center; /* current position */ 779 FT_Fixed line_length; /* length of last lineto */ 780 FT_Bool first_point; /* is this the start? */ 781 FT_Bool subpath_open; /* is the subpath open? */ 782 FT_Angle subpath_angle; /* subpath start direction */ 783 FT_Vector subpath_start; /* subpath start position */ 784 FT_Fixed subpath_line_length; /* subpath start lineto len */ 785 FT_Bool handle_wide_strokes; /* use wide strokes logic? */ 786 787 FT_Stroker_LineCap line_cap; 788 FT_Stroker_LineJoin line_join; 789 FT_Stroker_LineJoin line_join_saved; 790 FT_Fixed miter_limit; 791 FT_Fixed radius; 792 793 FT_StrokeBorderRec borders[2]; 794 FT_Library library; 795 796 } FT_StrokerRec; 797 798 799 /* documentation is in ftstroke.h */ 800 801 FT_EXPORT_DEF( FT_Error ) FT_Stroker_New(FT_Library library,FT_Stroker * astroker)802 FT_Stroker_New( FT_Library library, 803 FT_Stroker *astroker ) 804 { 805 FT_Error error; /* assigned in FT_NEW */ 806 FT_Memory memory; 807 FT_Stroker stroker = NULL; 808 809 810 if ( !library ) 811 return FT_THROW( Invalid_Library_Handle ); 812 813 if ( !astroker ) 814 return FT_THROW( Invalid_Argument ); 815 816 memory = library->memory; 817 818 if ( !FT_NEW( stroker ) ) 819 { 820 stroker->library = library; 821 822 ft_stroke_border_init( &stroker->borders[0], memory ); 823 ft_stroke_border_init( &stroker->borders[1], memory ); 824 } 825 826 *astroker = stroker; 827 828 return error; 829 } 830 831 832 /* documentation is in ftstroke.h */ 833 834 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)835 FT_Stroker_Set( FT_Stroker stroker, 836 FT_Fixed radius, 837 FT_Stroker_LineCap line_cap, 838 FT_Stroker_LineJoin line_join, 839 FT_Fixed miter_limit ) 840 { 841 if ( !stroker ) 842 return; 843 844 stroker->radius = radius; 845 stroker->line_cap = line_cap; 846 stroker->line_join = line_join; 847 stroker->miter_limit = miter_limit; 848 849 /* ensure miter limit has sensible value */ 850 if ( stroker->miter_limit < 0x10000L ) 851 stroker->miter_limit = 0x10000L; 852 853 /* save line join style: */ 854 /* line join style can be temporarily changed when stroking curves */ 855 stroker->line_join_saved = line_join; 856 857 FT_Stroker_Rewind( stroker ); 858 } 859 860 861 /* documentation is in ftstroke.h */ 862 863 FT_EXPORT_DEF( void ) FT_Stroker_Rewind(FT_Stroker stroker)864 FT_Stroker_Rewind( FT_Stroker stroker ) 865 { 866 if ( stroker ) 867 { 868 ft_stroke_border_reset( &stroker->borders[0] ); 869 ft_stroke_border_reset( &stroker->borders[1] ); 870 } 871 } 872 873 874 /* documentation is in ftstroke.h */ 875 876 FT_EXPORT_DEF( void ) FT_Stroker_Done(FT_Stroker stroker)877 FT_Stroker_Done( FT_Stroker stroker ) 878 { 879 if ( stroker ) 880 { 881 FT_Memory memory = stroker->library->memory; 882 883 884 ft_stroke_border_done( &stroker->borders[0] ); 885 ft_stroke_border_done( &stroker->borders[1] ); 886 887 stroker->library = NULL; 888 FT_FREE( stroker ); 889 } 890 } 891 892 893 /* create a circular arc at a corner or cap */ 894 static FT_Error ft_stroker_arcto(FT_Stroker stroker,FT_Int side)895 ft_stroker_arcto( FT_Stroker stroker, 896 FT_Int side ) 897 { 898 FT_Angle total, rotate; 899 FT_Fixed radius = stroker->radius; 900 FT_Error error = FT_Err_Ok; 901 FT_StrokeBorder border = stroker->borders + side; 902 903 904 rotate = FT_SIDE_TO_ROTATE( side ); 905 906 total = FT_Angle_Diff( stroker->angle_in, stroker->angle_out ); 907 if ( total == FT_ANGLE_PI ) 908 total = -rotate * 2; 909 910 error = ft_stroke_border_arcto( border, 911 &stroker->center, 912 radius, 913 stroker->angle_in + rotate, 914 total ); 915 border->movable = FALSE; 916 return error; 917 } 918 919 920 /* add a cap at the end of an opened path */ 921 static FT_Error ft_stroker_cap(FT_Stroker stroker,FT_Angle angle,FT_Int side)922 ft_stroker_cap( FT_Stroker stroker, 923 FT_Angle angle, 924 FT_Int side ) 925 { 926 FT_Error error = FT_Err_Ok; 927 928 929 if ( stroker->line_cap == FT_STROKER_LINECAP_ROUND ) 930 { 931 /* add a round cap */ 932 stroker->angle_in = angle; 933 stroker->angle_out = angle + FT_ANGLE_PI; 934 935 error = ft_stroker_arcto( stroker, side ); 936 } 937 else if ( stroker->line_cap == FT_STROKER_LINECAP_SQUARE ) 938 { 939 /* add a square cap */ 940 FT_Vector delta, delta2; 941 FT_Angle rotate = FT_SIDE_TO_ROTATE( side ); 942 FT_Fixed radius = stroker->radius; 943 FT_StrokeBorder border = stroker->borders + side; 944 945 946 FT_Vector_From_Polar( &delta2, radius, angle + rotate ); 947 FT_Vector_From_Polar( &delta, radius, angle ); 948 949 delta.x += stroker->center.x + delta2.x; 950 delta.y += stroker->center.y + delta2.y; 951 952 error = ft_stroke_border_lineto( border, &delta, FALSE ); 953 if ( error ) 954 goto Exit; 955 956 FT_Vector_From_Polar( &delta2, radius, angle - rotate ); 957 FT_Vector_From_Polar( &delta, radius, angle ); 958 959 delta.x += delta2.x + stroker->center.x; 960 delta.y += delta2.y + stroker->center.y; 961 962 error = ft_stroke_border_lineto( border, &delta, FALSE ); 963 } 964 else if ( stroker->line_cap == FT_STROKER_LINECAP_BUTT ) 965 { 966 /* add a butt ending */ 967 FT_Vector delta; 968 FT_Angle rotate = FT_SIDE_TO_ROTATE( side ); 969 FT_Fixed radius = stroker->radius; 970 FT_StrokeBorder border = stroker->borders + side; 971 972 973 FT_Vector_From_Polar( &delta, radius, angle + rotate ); 974 975 delta.x += stroker->center.x; 976 delta.y += stroker->center.y; 977 978 error = ft_stroke_border_lineto( border, &delta, FALSE ); 979 if ( error ) 980 goto Exit; 981 982 FT_Vector_From_Polar( &delta, radius, angle - rotate ); 983 984 delta.x += stroker->center.x; 985 delta.y += stroker->center.y; 986 987 error = ft_stroke_border_lineto( border, &delta, FALSE ); 988 } 989 990 Exit: 991 return error; 992 } 993 994 995 /* process an inside corner, i.e. compute intersection */ 996 static FT_Error ft_stroker_inside(FT_Stroker stroker,FT_Int side,FT_Fixed line_length)997 ft_stroker_inside( FT_Stroker stroker, 998 FT_Int side, 999 FT_Fixed line_length ) 1000 { 1001 FT_StrokeBorder border = stroker->borders + side; 1002 FT_Angle phi, theta, rotate; 1003 FT_Fixed length, thcos; 1004 FT_Vector delta; 1005 FT_Error error = FT_Err_Ok; 1006 FT_Bool intersect; /* use intersection of lines? */ 1007 1008 1009 rotate = FT_SIDE_TO_ROTATE( side ); 1010 1011 theta = FT_Angle_Diff( stroker->angle_in, stroker->angle_out ) / 2; 1012 1013 /* Only intersect borders if between two lineto's and both */ 1014 /* lines are long enough (line_length is zero for curves). */ 1015 /* Also avoid U-turns of nearly 180 degree. */ 1016 if ( !border->movable || line_length == 0 || 1017 theta > 0x59C000 || theta < -0x59C000 ) 1018 intersect = FALSE; 1019 else 1020 { 1021 /* compute minimum required length of lines */ 1022 FT_Fixed min_length = ft_pos_abs( FT_MulFix( stroker->radius, 1023 FT_Tan( theta ) ) ); 1024 1025 1026 intersect = FT_BOOL( min_length && 1027 stroker->line_length >= min_length && 1028 line_length >= min_length ); 1029 } 1030 1031 if ( !intersect ) 1032 { 1033 FT_Vector_From_Polar( &delta, stroker->radius, 1034 stroker->angle_out + rotate ); 1035 delta.x += stroker->center.x; 1036 delta.y += stroker->center.y; 1037 1038 border->movable = FALSE; 1039 } 1040 else 1041 { 1042 /* compute median angle */ 1043 phi = stroker->angle_in + theta; 1044 1045 thcos = FT_Cos( theta ); 1046 1047 length = FT_DivFix( stroker->radius, thcos ); 1048 1049 FT_Vector_From_Polar( &delta, length, phi + rotate ); 1050 delta.x += stroker->center.x; 1051 delta.y += stroker->center.y; 1052 } 1053 1054 error = ft_stroke_border_lineto( border, &delta, FALSE ); 1055 1056 return error; 1057 } 1058 1059 1060 /* process an outside corner, i.e. compute bevel/miter/round */ 1061 static FT_Error ft_stroker_outside(FT_Stroker stroker,FT_Int side,FT_Fixed line_length)1062 ft_stroker_outside( FT_Stroker stroker, 1063 FT_Int side, 1064 FT_Fixed line_length ) 1065 { 1066 FT_StrokeBorder border = stroker->borders + side; 1067 FT_Error error; 1068 FT_Angle rotate; 1069 1070 1071 if ( stroker->line_join == FT_STROKER_LINEJOIN_ROUND ) 1072 error = ft_stroker_arcto( stroker, side ); 1073 else 1074 { 1075 /* this is a mitered (pointed) or beveled (truncated) corner */ 1076 FT_Fixed sigma = 0, radius = stroker->radius; 1077 FT_Angle theta = 0, phi = 0; 1078 FT_Fixed thcos = 0; 1079 FT_Bool bevel, fixed_bevel; 1080 1081 1082 rotate = FT_SIDE_TO_ROTATE( side ); 1083 1084 bevel = 1085 FT_BOOL( stroker->line_join == FT_STROKER_LINEJOIN_BEVEL ); 1086 1087 fixed_bevel = 1088 FT_BOOL( stroker->line_join != FT_STROKER_LINEJOIN_MITER_VARIABLE ); 1089 1090 if ( !bevel ) 1091 { 1092 theta = FT_Angle_Diff( stroker->angle_in, stroker->angle_out ); 1093 1094 if ( theta == FT_ANGLE_PI ) 1095 { 1096 theta = rotate; 1097 phi = stroker->angle_in; 1098 } 1099 else 1100 { 1101 theta /= 2; 1102 phi = stroker->angle_in + theta + rotate; 1103 } 1104 1105 thcos = FT_Cos( theta ); 1106 sigma = FT_MulFix( stroker->miter_limit, thcos ); 1107 1108 /* is miter limit exceeded? */ 1109 if ( sigma < 0x10000L ) 1110 { 1111 /* don't create variable bevels for very small deviations; */ 1112 /* FT_Sin(x) = 0 for x <= 57 */ 1113 if ( fixed_bevel || ft_pos_abs( theta ) > 57 ) 1114 bevel = TRUE; 1115 } 1116 } 1117 1118 if ( bevel ) /* this is a bevel (broken angle) */ 1119 { 1120 if ( fixed_bevel ) 1121 { 1122 /* the outer corners are simply joined together */ 1123 FT_Vector delta; 1124 1125 1126 /* add bevel */ 1127 FT_Vector_From_Polar( &delta, 1128 radius, 1129 stroker->angle_out + rotate ); 1130 delta.x += stroker->center.x; 1131 delta.y += stroker->center.y; 1132 1133 border->movable = FALSE; 1134 error = ft_stroke_border_lineto( border, &delta, FALSE ); 1135 } 1136 else /* variable bevel */ 1137 { 1138 /* the miter is truncated */ 1139 FT_Vector middle, delta; 1140 FT_Fixed length; 1141 1142 1143 /* compute middle point */ 1144 FT_Vector_From_Polar( &middle, 1145 FT_MulFix( radius, stroker->miter_limit ), 1146 phi ); 1147 middle.x += stroker->center.x; 1148 middle.y += stroker->center.y; 1149 1150 /* compute first angle point */ 1151 length = FT_MulDiv( radius, 0x10000L - sigma, 1152 ft_pos_abs( FT_Sin( theta ) ) ); 1153 1154 FT_Vector_From_Polar( &delta, length, phi + rotate ); 1155 delta.x += middle.x; 1156 delta.y += middle.y; 1157 1158 error = ft_stroke_border_lineto( border, &delta, FALSE ); 1159 if ( error ) 1160 goto Exit; 1161 1162 /* compute second angle point */ 1163 FT_Vector_From_Polar( &delta, length, phi - rotate ); 1164 delta.x += middle.x; 1165 delta.y += middle.y; 1166 1167 error = ft_stroke_border_lineto( border, &delta, FALSE ); 1168 if ( error ) 1169 goto Exit; 1170 1171 /* finally, add an end point; only needed if not lineto */ 1172 /* (line_length is zero for curves) */ 1173 if ( line_length == 0 ) 1174 { 1175 FT_Vector_From_Polar( &delta, 1176 radius, 1177 stroker->angle_out + rotate ); 1178 1179 delta.x += stroker->center.x; 1180 delta.y += stroker->center.y; 1181 1182 error = ft_stroke_border_lineto( border, &delta, FALSE ); 1183 } 1184 } 1185 } 1186 else /* this is a miter (intersection) */ 1187 { 1188 FT_Fixed length; 1189 FT_Vector delta; 1190 1191 1192 length = FT_DivFix( stroker->radius, thcos ); 1193 1194 FT_Vector_From_Polar( &delta, length, phi ); 1195 delta.x += stroker->center.x; 1196 delta.y += stroker->center.y; 1197 1198 error = ft_stroke_border_lineto( border, &delta, FALSE ); 1199 if ( error ) 1200 goto Exit; 1201 1202 /* now add an end point; only needed if not lineto */ 1203 /* (line_length is zero for curves) */ 1204 if ( line_length == 0 ) 1205 { 1206 FT_Vector_From_Polar( &delta, 1207 stroker->radius, 1208 stroker->angle_out + rotate ); 1209 delta.x += stroker->center.x; 1210 delta.y += stroker->center.y; 1211 1212 error = ft_stroke_border_lineto( border, &delta, FALSE ); 1213 } 1214 } 1215 } 1216 1217 Exit: 1218 return error; 1219 } 1220 1221 1222 static FT_Error ft_stroker_process_corner(FT_Stroker stroker,FT_Fixed line_length)1223 ft_stroker_process_corner( FT_Stroker stroker, 1224 FT_Fixed line_length ) 1225 { 1226 FT_Error error = FT_Err_Ok; 1227 FT_Angle turn; 1228 FT_Int inside_side; 1229 1230 1231 turn = FT_Angle_Diff( stroker->angle_in, stroker->angle_out ); 1232 1233 /* no specific corner processing is required if the turn is 0 */ 1234 if ( turn == 0 ) 1235 goto Exit; 1236 1237 /* when we turn to the right, the inside side is 0 */ 1238 /* otherwise, the inside side is 1 */ 1239 inside_side = ( turn < 0 ); 1240 1241 /* process the inside side */ 1242 error = ft_stroker_inside( stroker, inside_side, line_length ); 1243 if ( error ) 1244 goto Exit; 1245 1246 /* process the outside side */ 1247 error = ft_stroker_outside( stroker, !inside_side, line_length ); 1248 1249 Exit: 1250 return error; 1251 } 1252 1253 1254 /* add two points to the left and right borders corresponding to the */ 1255 /* start of the subpath */ 1256 static FT_Error ft_stroker_subpath_start(FT_Stroker stroker,FT_Angle start_angle,FT_Fixed line_length)1257 ft_stroker_subpath_start( FT_Stroker stroker, 1258 FT_Angle start_angle, 1259 FT_Fixed line_length ) 1260 { 1261 FT_Vector delta; 1262 FT_Vector point; 1263 FT_Error error; 1264 FT_StrokeBorder border; 1265 1266 1267 FT_Vector_From_Polar( &delta, stroker->radius, 1268 start_angle + FT_ANGLE_PI2 ); 1269 1270 point.x = stroker->center.x + delta.x; 1271 point.y = stroker->center.y + delta.y; 1272 1273 border = stroker->borders; 1274 error = ft_stroke_border_moveto( border, &point ); 1275 if ( error ) 1276 goto Exit; 1277 1278 point.x = stroker->center.x - delta.x; 1279 point.y = stroker->center.y - delta.y; 1280 1281 border++; 1282 error = ft_stroke_border_moveto( border, &point ); 1283 1284 /* save angle, position, and line length for last join */ 1285 /* (line_length is zero for curves) */ 1286 stroker->subpath_angle = start_angle; 1287 stroker->first_point = FALSE; 1288 stroker->subpath_line_length = line_length; 1289 1290 Exit: 1291 return error; 1292 } 1293 1294 1295 /* documentation is in ftstroke.h */ 1296 1297 FT_EXPORT_DEF( FT_Error ) FT_Stroker_LineTo(FT_Stroker stroker,FT_Vector * to)1298 FT_Stroker_LineTo( FT_Stroker stroker, 1299 FT_Vector* to ) 1300 { 1301 FT_Error error = FT_Err_Ok; 1302 FT_StrokeBorder border; 1303 FT_Vector delta; 1304 FT_Angle angle; 1305 FT_Int side; 1306 FT_Fixed line_length; 1307 1308 1309 if ( !stroker || !to ) 1310 return FT_THROW( Invalid_Argument ); 1311 1312 delta.x = to->x - stroker->center.x; 1313 delta.y = to->y - stroker->center.y; 1314 1315 /* a zero-length lineto is a no-op; avoid creating a spurious corner */ 1316 if ( delta.x == 0 && delta.y == 0 ) 1317 goto Exit; 1318 1319 /* compute length of line */ 1320 line_length = FT_Vector_Length( &delta ); 1321 1322 angle = FT_Atan2( delta.x, delta.y ); 1323 FT_Vector_From_Polar( &delta, stroker->radius, angle + FT_ANGLE_PI2 ); 1324 1325 /* process corner if necessary */ 1326 if ( stroker->first_point ) 1327 { 1328 /* This is the first segment of a subpath. We need to */ 1329 /* add a point to each border at their respective starting */ 1330 /* point locations. */ 1331 error = ft_stroker_subpath_start( stroker, angle, line_length ); 1332 if ( error ) 1333 goto Exit; 1334 } 1335 else 1336 { 1337 /* process the current corner */ 1338 stroker->angle_out = angle; 1339 error = ft_stroker_process_corner( stroker, line_length ); 1340 if ( error ) 1341 goto Exit; 1342 } 1343 1344 /* now add a line segment to both the `inside' and `outside' paths */ 1345 for ( border = stroker->borders, side = 1; side >= 0; side--, border++ ) 1346 { 1347 FT_Vector point; 1348 1349 1350 point.x = to->x + delta.x; 1351 point.y = to->y + delta.y; 1352 1353 /* the ends of lineto borders are movable */ 1354 error = ft_stroke_border_lineto( border, &point, TRUE ); 1355 if ( error ) 1356 goto Exit; 1357 1358 delta.x = -delta.x; 1359 delta.y = -delta.y; 1360 } 1361 1362 stroker->angle_in = angle; 1363 stroker->center = *to; 1364 stroker->line_length = line_length; 1365 1366 Exit: 1367 return error; 1368 } 1369 1370 1371 /* documentation is in ftstroke.h */ 1372 1373 FT_EXPORT_DEF( FT_Error ) FT_Stroker_ConicTo(FT_Stroker stroker,FT_Vector * control,FT_Vector * to)1374 FT_Stroker_ConicTo( FT_Stroker stroker, 1375 FT_Vector* control, 1376 FT_Vector* to ) 1377 { 1378 FT_Error error = FT_Err_Ok; 1379 FT_Vector bez_stack[34]; 1380 FT_Vector* arc; 1381 FT_Vector* limit = bez_stack + 30; 1382 FT_Bool first_arc = TRUE; 1383 1384 1385 if ( !stroker || !control || !to ) 1386 { 1387 error = FT_THROW( Invalid_Argument ); 1388 goto Exit; 1389 } 1390 1391 /* if all control points are coincident, this is a no-op; */ 1392 /* avoid creating a spurious corner */ 1393 if ( FT_IS_SMALL( stroker->center.x - control->x ) && 1394 FT_IS_SMALL( stroker->center.y - control->y ) && 1395 FT_IS_SMALL( control->x - to->x ) && 1396 FT_IS_SMALL( control->y - to->y ) ) 1397 { 1398 stroker->center = *to; 1399 goto Exit; 1400 } 1401 1402 arc = bez_stack; 1403 arc[0] = *to; 1404 arc[1] = *control; 1405 arc[2] = stroker->center; 1406 1407 while ( arc >= bez_stack ) 1408 { 1409 FT_Angle angle_in, angle_out; 1410 1411 1412 /* initialize with current direction */ 1413 angle_in = angle_out = stroker->angle_in; 1414 1415 if ( arc < limit && 1416 !ft_conic_is_small_enough( arc, &angle_in, &angle_out ) ) 1417 { 1418 if ( stroker->first_point ) 1419 stroker->angle_in = angle_in; 1420 1421 ft_conic_split( arc ); 1422 arc += 2; 1423 continue; 1424 } 1425 1426 if ( first_arc ) 1427 { 1428 first_arc = FALSE; 1429 1430 /* process corner if necessary */ 1431 if ( stroker->first_point ) 1432 error = ft_stroker_subpath_start( stroker, angle_in, 0 ); 1433 else 1434 { 1435 stroker->angle_out = angle_in; 1436 error = ft_stroker_process_corner( stroker, 0 ); 1437 } 1438 } 1439 else if ( ft_pos_abs( FT_Angle_Diff( stroker->angle_in, angle_in ) ) > 1440 FT_SMALL_CONIC_THRESHOLD / 4 ) 1441 { 1442 /* if the deviation from one arc to the next is too great, */ 1443 /* add a round corner */ 1444 stroker->center = arc[2]; 1445 stroker->angle_out = angle_in; 1446 stroker->line_join = FT_STROKER_LINEJOIN_ROUND; 1447 1448 error = ft_stroker_process_corner( stroker, 0 ); 1449 1450 /* reinstate line join style */ 1451 stroker->line_join = stroker->line_join_saved; 1452 } 1453 1454 if ( error ) 1455 goto Exit; 1456 1457 /* the arc's angle is small enough; we can add it directly to each */ 1458 /* border */ 1459 { 1460 FT_Vector ctrl, end; 1461 FT_Angle theta, phi, rotate, alpha0 = 0; 1462 FT_Fixed length; 1463 FT_StrokeBorder border; 1464 FT_Int side; 1465 1466 1467 theta = FT_Angle_Diff( angle_in, angle_out ) / 2; 1468 phi = angle_in + theta; 1469 length = FT_DivFix( stroker->radius, FT_Cos( theta ) ); 1470 1471 /* compute direction of original arc */ 1472 if ( stroker->handle_wide_strokes ) 1473 alpha0 = FT_Atan2( arc[0].x - arc[2].x, arc[0].y - arc[2].y ); 1474 1475 for ( border = stroker->borders, side = 0; 1476 side <= 1; 1477 side++, border++ ) 1478 { 1479 rotate = FT_SIDE_TO_ROTATE( side ); 1480 1481 /* compute control point */ 1482 FT_Vector_From_Polar( &ctrl, length, phi + rotate ); 1483 ctrl.x += arc[1].x; 1484 ctrl.y += arc[1].y; 1485 1486 /* compute end point */ 1487 FT_Vector_From_Polar( &end, stroker->radius, angle_out + rotate ); 1488 end.x += arc[0].x; 1489 end.y += arc[0].y; 1490 1491 if ( stroker->handle_wide_strokes ) 1492 { 1493 FT_Vector start; 1494 FT_Angle alpha1; 1495 1496 1497 /* determine whether the border radius is greater than the */ 1498 /* radius of curvature of the original arc */ 1499 start = border->points[border->num_points - 1]; 1500 1501 alpha1 = FT_Atan2( end.x - start.x, end.y - start.y ); 1502 1503 /* is the direction of the border arc opposite to */ 1504 /* that of the original arc? */ 1505 if ( ft_pos_abs( FT_Angle_Diff( alpha0, alpha1 ) ) > 1506 FT_ANGLE_PI / 2 ) 1507 { 1508 FT_Angle beta, gamma; 1509 FT_Vector bvec, delta; 1510 FT_Fixed blen, sinA, sinB, alen; 1511 1512 1513 /* use the sine rule to find the intersection point */ 1514 beta = FT_Atan2( arc[2].x - start.x, arc[2].y - start.y ); 1515 gamma = FT_Atan2( arc[0].x - end.x, arc[0].y - end.y ); 1516 1517 bvec.x = end.x - start.x; 1518 bvec.y = end.y - start.y; 1519 1520 blen = FT_Vector_Length( &bvec ); 1521 1522 sinA = ft_pos_abs( FT_Sin( alpha1 - gamma ) ); 1523 sinB = ft_pos_abs( FT_Sin( beta - gamma ) ); 1524 1525 alen = FT_MulDiv( blen, sinA, sinB ); 1526 1527 FT_Vector_From_Polar( &delta, alen, beta ); 1528 delta.x += start.x; 1529 delta.y += start.y; 1530 1531 /* circumnavigate the negative sector backwards */ 1532 border->movable = FALSE; 1533 error = ft_stroke_border_lineto( border, &delta, FALSE ); 1534 if ( error ) 1535 goto Exit; 1536 error = ft_stroke_border_lineto( border, &end, FALSE ); 1537 if ( error ) 1538 goto Exit; 1539 error = ft_stroke_border_conicto( border, &ctrl, &start ); 1540 if ( error ) 1541 goto Exit; 1542 /* and then move to the endpoint */ 1543 error = ft_stroke_border_lineto( border, &end, FALSE ); 1544 if ( error ) 1545 goto Exit; 1546 1547 continue; 1548 } 1549 1550 /* else fall through */ 1551 } 1552 1553 /* simply add an arc */ 1554 error = ft_stroke_border_conicto( border, &ctrl, &end ); 1555 if ( error ) 1556 goto Exit; 1557 } 1558 } 1559 1560 arc -= 2; 1561 1562 stroker->angle_in = angle_out; 1563 } 1564 1565 stroker->center = *to; 1566 1567 Exit: 1568 return error; 1569 } 1570 1571 1572 /* documentation is in ftstroke.h */ 1573 1574 FT_EXPORT_DEF( FT_Error ) FT_Stroker_CubicTo(FT_Stroker stroker,FT_Vector * control1,FT_Vector * control2,FT_Vector * to)1575 FT_Stroker_CubicTo( FT_Stroker stroker, 1576 FT_Vector* control1, 1577 FT_Vector* control2, 1578 FT_Vector* to ) 1579 { 1580 FT_Error error = FT_Err_Ok; 1581 FT_Vector bez_stack[37]; 1582 FT_Vector* arc; 1583 FT_Vector* limit = bez_stack + 32; 1584 FT_Bool first_arc = TRUE; 1585 1586 1587 if ( !stroker || !control1 || !control2 || !to ) 1588 { 1589 error = FT_THROW( Invalid_Argument ); 1590 goto Exit; 1591 } 1592 1593 /* if all control points are coincident, this is a no-op; */ 1594 /* avoid creating a spurious corner */ 1595 if ( FT_IS_SMALL( stroker->center.x - control1->x ) && 1596 FT_IS_SMALL( stroker->center.y - control1->y ) && 1597 FT_IS_SMALL( control1->x - control2->x ) && 1598 FT_IS_SMALL( control1->y - control2->y ) && 1599 FT_IS_SMALL( control2->x - to->x ) && 1600 FT_IS_SMALL( control2->y - to->y ) ) 1601 { 1602 stroker->center = *to; 1603 goto Exit; 1604 } 1605 1606 arc = bez_stack; 1607 arc[0] = *to; 1608 arc[1] = *control2; 1609 arc[2] = *control1; 1610 arc[3] = stroker->center; 1611 1612 while ( arc >= bez_stack ) 1613 { 1614 FT_Angle angle_in, angle_mid, angle_out; 1615 1616 1617 /* initialize with current direction */ 1618 angle_in = angle_out = angle_mid = stroker->angle_in; 1619 1620 if ( arc < limit && 1621 !ft_cubic_is_small_enough( arc, &angle_in, 1622 &angle_mid, &angle_out ) ) 1623 { 1624 if ( stroker->first_point ) 1625 stroker->angle_in = angle_in; 1626 1627 ft_cubic_split( arc ); 1628 arc += 3; 1629 continue; 1630 } 1631 1632 if ( first_arc ) 1633 { 1634 first_arc = FALSE; 1635 1636 /* process corner if necessary */ 1637 if ( stroker->first_point ) 1638 error = ft_stroker_subpath_start( stroker, angle_in, 0 ); 1639 else 1640 { 1641 stroker->angle_out = angle_in; 1642 error = ft_stroker_process_corner( stroker, 0 ); 1643 } 1644 } 1645 else if ( ft_pos_abs( FT_Angle_Diff( stroker->angle_in, angle_in ) ) > 1646 FT_SMALL_CUBIC_THRESHOLD / 4 ) 1647 { 1648 /* if the deviation from one arc to the next is too great, */ 1649 /* add a round corner */ 1650 stroker->center = arc[3]; 1651 stroker->angle_out = angle_in; 1652 stroker->line_join = FT_STROKER_LINEJOIN_ROUND; 1653 1654 error = ft_stroker_process_corner( stroker, 0 ); 1655 1656 /* reinstate line join style */ 1657 stroker->line_join = stroker->line_join_saved; 1658 } 1659 1660 if ( error ) 1661 goto Exit; 1662 1663 /* the arc's angle is small enough; we can add it directly to each */ 1664 /* border */ 1665 { 1666 FT_Vector ctrl1, ctrl2, end; 1667 FT_Angle theta1, phi1, theta2, phi2, rotate, alpha0 = 0; 1668 FT_Fixed length1, length2; 1669 FT_StrokeBorder border; 1670 FT_Int side; 1671 1672 1673 theta1 = FT_Angle_Diff( angle_in, angle_mid ) / 2; 1674 theta2 = FT_Angle_Diff( angle_mid, angle_out ) / 2; 1675 phi1 = ft_angle_mean( angle_in, angle_mid ); 1676 phi2 = ft_angle_mean( angle_mid, angle_out ); 1677 length1 = FT_DivFix( stroker->radius, FT_Cos( theta1 ) ); 1678 length2 = FT_DivFix( stroker->radius, FT_Cos( theta2 ) ); 1679 1680 /* compute direction of original arc */ 1681 if ( stroker->handle_wide_strokes ) 1682 alpha0 = FT_Atan2( arc[0].x - arc[3].x, arc[0].y - arc[3].y ); 1683 1684 for ( border = stroker->borders, side = 0; 1685 side <= 1; 1686 side++, border++ ) 1687 { 1688 rotate = FT_SIDE_TO_ROTATE( side ); 1689 1690 /* compute control points */ 1691 FT_Vector_From_Polar( &ctrl1, length1, phi1 + rotate ); 1692 ctrl1.x += arc[2].x; 1693 ctrl1.y += arc[2].y; 1694 1695 FT_Vector_From_Polar( &ctrl2, length2, phi2 + rotate ); 1696 ctrl2.x += arc[1].x; 1697 ctrl2.y += arc[1].y; 1698 1699 /* compute end point */ 1700 FT_Vector_From_Polar( &end, stroker->radius, angle_out + rotate ); 1701 end.x += arc[0].x; 1702 end.y += arc[0].y; 1703 1704 if ( stroker->handle_wide_strokes ) 1705 { 1706 FT_Vector start; 1707 FT_Angle alpha1; 1708 1709 1710 /* determine whether the border radius is greater than the */ 1711 /* radius of curvature of the original arc */ 1712 start = border->points[border->num_points - 1]; 1713 1714 alpha1 = FT_Atan2( end.x - start.x, end.y - start.y ); 1715 1716 /* is the direction of the border arc opposite to */ 1717 /* that of the original arc? */ 1718 if ( ft_pos_abs( FT_Angle_Diff( alpha0, alpha1 ) ) > 1719 FT_ANGLE_PI / 2 ) 1720 { 1721 FT_Angle beta, gamma; 1722 FT_Vector bvec, delta; 1723 FT_Fixed blen, sinA, sinB, alen; 1724 1725 1726 /* use the sine rule to find the intersection point */ 1727 beta = FT_Atan2( arc[3].x - start.x, arc[3].y - start.y ); 1728 gamma = FT_Atan2( arc[0].x - end.x, arc[0].y - end.y ); 1729 1730 bvec.x = end.x - start.x; 1731 bvec.y = end.y - start.y; 1732 1733 blen = FT_Vector_Length( &bvec ); 1734 1735 sinA = ft_pos_abs( FT_Sin( alpha1 - gamma ) ); 1736 sinB = ft_pos_abs( FT_Sin( beta - gamma ) ); 1737 1738 alen = FT_MulDiv( blen, sinA, sinB ); 1739 1740 FT_Vector_From_Polar( &delta, alen, beta ); 1741 delta.x += start.x; 1742 delta.y += start.y; 1743 1744 /* circumnavigate the negative sector backwards */ 1745 border->movable = FALSE; 1746 error = ft_stroke_border_lineto( border, &delta, FALSE ); 1747 if ( error ) 1748 goto Exit; 1749 error = ft_stroke_border_lineto( border, &end, FALSE ); 1750 if ( error ) 1751 goto Exit; 1752 error = ft_stroke_border_cubicto( border, 1753 &ctrl2, 1754 &ctrl1, 1755 &start ); 1756 if ( error ) 1757 goto Exit; 1758 /* and then move to the endpoint */ 1759 error = ft_stroke_border_lineto( border, &end, FALSE ); 1760 if ( error ) 1761 goto Exit; 1762 1763 continue; 1764 } 1765 1766 /* else fall through */ 1767 } 1768 1769 /* simply add an arc */ 1770 error = ft_stroke_border_cubicto( border, &ctrl1, &ctrl2, &end ); 1771 if ( error ) 1772 goto Exit; 1773 } 1774 } 1775 1776 arc -= 3; 1777 1778 stroker->angle_in = angle_out; 1779 } 1780 1781 stroker->center = *to; 1782 1783 Exit: 1784 return error; 1785 } 1786 1787 1788 /* documentation is in ftstroke.h */ 1789 1790 FT_EXPORT_DEF( FT_Error ) FT_Stroker_BeginSubPath(FT_Stroker stroker,FT_Vector * to,FT_Bool open)1791 FT_Stroker_BeginSubPath( FT_Stroker stroker, 1792 FT_Vector* to, 1793 FT_Bool open ) 1794 { 1795 if ( !stroker || !to ) 1796 return FT_THROW( Invalid_Argument ); 1797 1798 /* We cannot process the first point, because there is not enough */ 1799 /* information regarding its corner/cap. The latter will be processed */ 1800 /* in the `FT_Stroker_EndSubPath' routine. */ 1801 /* */ 1802 stroker->first_point = TRUE; 1803 stroker->center = *to; 1804 stroker->subpath_open = open; 1805 1806 /* Determine if we need to check whether the border radius is greater */ 1807 /* than the radius of curvature of a curve, to handle this case */ 1808 /* specially. This is only required if bevel joins or butt caps may */ 1809 /* be created, because round & miter joins and round & square caps */ 1810 /* cover the negative sector created with wide strokes. */ 1811 stroker->handle_wide_strokes = 1812 FT_BOOL( stroker->line_join != FT_STROKER_LINEJOIN_ROUND || 1813 ( stroker->subpath_open && 1814 stroker->line_cap == FT_STROKER_LINECAP_BUTT ) ); 1815 1816 /* record the subpath start point for each border */ 1817 stroker->subpath_start = *to; 1818 1819 stroker->angle_in = 0; 1820 1821 return FT_Err_Ok; 1822 } 1823 1824 1825 static FT_Error ft_stroker_add_reverse_left(FT_Stroker stroker,FT_Bool open)1826 ft_stroker_add_reverse_left( FT_Stroker stroker, 1827 FT_Bool open ) 1828 { 1829 FT_StrokeBorder right = stroker->borders + 0; 1830 FT_StrokeBorder left = stroker->borders + 1; 1831 FT_Int new_points; 1832 FT_Error error = FT_Err_Ok; 1833 1834 1835 FT_ASSERT( left->start >= 0 ); 1836 1837 new_points = (FT_Int)left->num_points - left->start; 1838 if ( new_points > 0 ) 1839 { 1840 error = ft_stroke_border_grow( right, (FT_UInt)new_points ); 1841 if ( error ) 1842 goto Exit; 1843 1844 { 1845 FT_Vector* dst_point = right->points + right->num_points; 1846 FT_Byte* dst_tag = right->tags + right->num_points; 1847 FT_Vector* src_point = left->points + left->num_points - 1; 1848 FT_Byte* src_tag = left->tags + left->num_points - 1; 1849 1850 1851 while ( src_point >= left->points + left->start ) 1852 { 1853 *dst_point = *src_point; 1854 *dst_tag = *src_tag; 1855 1856 if ( open ) 1857 dst_tag[0] &= ~FT_STROKE_TAG_BEGIN_END; 1858 else 1859 { 1860 FT_Byte ttag = 1861 (FT_Byte)( dst_tag[0] & FT_STROKE_TAG_BEGIN_END ); 1862 1863 1864 /* switch begin/end tags if necessary */ 1865 if ( ttag == FT_STROKE_TAG_BEGIN || 1866 ttag == FT_STROKE_TAG_END ) 1867 dst_tag[0] ^= FT_STROKE_TAG_BEGIN_END; 1868 } 1869 1870 src_point--; 1871 src_tag--; 1872 dst_point++; 1873 dst_tag++; 1874 } 1875 } 1876 1877 left->num_points = (FT_UInt)left->start; 1878 right->num_points += (FT_UInt)new_points; 1879 1880 right->movable = FALSE; 1881 left->movable = FALSE; 1882 } 1883 1884 Exit: 1885 return error; 1886 } 1887 1888 1889 /* documentation is in ftstroke.h */ 1890 1891 /* there's a lot of magic in this function! */ 1892 FT_EXPORT_DEF( FT_Error ) FT_Stroker_EndSubPath(FT_Stroker stroker)1893 FT_Stroker_EndSubPath( FT_Stroker stroker ) 1894 { 1895 FT_Error error = FT_Err_Ok; 1896 1897 1898 if ( !stroker ) 1899 { 1900 error = FT_THROW( Invalid_Argument ); 1901 goto Exit; 1902 } 1903 1904 if ( stroker->subpath_open ) 1905 { 1906 FT_StrokeBorder right = stroker->borders; 1907 1908 1909 /* All right, this is an opened path, we need to add a cap between */ 1910 /* right & left, add the reverse of left, then add a final cap */ 1911 /* between left & right. */ 1912 error = ft_stroker_cap( stroker, stroker->angle_in, 0 ); 1913 if ( error ) 1914 goto Exit; 1915 1916 /* add reversed points from `left' to `right' */ 1917 error = ft_stroker_add_reverse_left( stroker, TRUE ); 1918 if ( error ) 1919 goto Exit; 1920 1921 /* now add the final cap */ 1922 stroker->center = stroker->subpath_start; 1923 error = ft_stroker_cap( stroker, 1924 stroker->subpath_angle + FT_ANGLE_PI, 0 ); 1925 if ( error ) 1926 goto Exit; 1927 1928 /* Now end the right subpath accordingly. The left one is */ 1929 /* rewind and doesn't need further processing. */ 1930 ft_stroke_border_close( right, FALSE ); 1931 } 1932 else 1933 { 1934 FT_Angle turn; 1935 FT_Int inside_side; 1936 1937 1938 /* close the path if needed */ 1939 if ( stroker->center.x != stroker->subpath_start.x || 1940 stroker->center.y != stroker->subpath_start.y ) 1941 { 1942 error = FT_Stroker_LineTo( stroker, &stroker->subpath_start ); 1943 if ( error ) 1944 goto Exit; 1945 } 1946 1947 /* process the corner */ 1948 stroker->angle_out = stroker->subpath_angle; 1949 turn = FT_Angle_Diff( stroker->angle_in, 1950 stroker->angle_out ); 1951 1952 /* no specific corner processing is required if the turn is 0 */ 1953 if ( turn != 0 ) 1954 { 1955 /* when we turn to the right, the inside side is 0 */ 1956 /* otherwise, the inside side is 1 */ 1957 inside_side = ( turn < 0 ); 1958 1959 error = ft_stroker_inside( stroker, 1960 inside_side, 1961 stroker->subpath_line_length ); 1962 if ( error ) 1963 goto Exit; 1964 1965 /* process the outside side */ 1966 error = ft_stroker_outside( stroker, 1967 !inside_side, 1968 stroker->subpath_line_length ); 1969 if ( error ) 1970 goto Exit; 1971 } 1972 1973 /* then end our two subpaths */ 1974 ft_stroke_border_close( stroker->borders + 0, FALSE ); 1975 ft_stroke_border_close( stroker->borders + 1, TRUE ); 1976 } 1977 1978 Exit: 1979 return error; 1980 } 1981 1982 1983 /* documentation is in ftstroke.h */ 1984 1985 FT_EXPORT_DEF( FT_Error ) FT_Stroker_GetBorderCounts(FT_Stroker stroker,FT_StrokerBorder border,FT_UInt * anum_points,FT_UInt * anum_contours)1986 FT_Stroker_GetBorderCounts( FT_Stroker stroker, 1987 FT_StrokerBorder border, 1988 FT_UInt *anum_points, 1989 FT_UInt *anum_contours ) 1990 { 1991 FT_UInt num_points = 0, num_contours = 0; 1992 FT_Error error; 1993 1994 1995 if ( !stroker || border > 1 ) 1996 { 1997 error = FT_THROW( Invalid_Argument ); 1998 goto Exit; 1999 } 2000 2001 error = ft_stroke_border_get_counts( stroker->borders + border, 2002 &num_points, &num_contours ); 2003 Exit: 2004 if ( anum_points ) 2005 *anum_points = num_points; 2006 2007 if ( anum_contours ) 2008 *anum_contours = num_contours; 2009 2010 return error; 2011 } 2012 2013 2014 /* documentation is in ftstroke.h */ 2015 2016 FT_EXPORT_DEF( FT_Error ) FT_Stroker_GetCounts(FT_Stroker stroker,FT_UInt * anum_points,FT_UInt * anum_contours)2017 FT_Stroker_GetCounts( FT_Stroker stroker, 2018 FT_UInt *anum_points, 2019 FT_UInt *anum_contours ) 2020 { 2021 FT_UInt count1, count2, num_points = 0; 2022 FT_UInt count3, count4, num_contours = 0; 2023 FT_Error error; 2024 2025 2026 if ( !stroker ) 2027 { 2028 error = FT_THROW( Invalid_Argument ); 2029 goto Exit; 2030 } 2031 2032 error = ft_stroke_border_get_counts( stroker->borders + 0, 2033 &count1, &count2 ); 2034 if ( error ) 2035 goto Exit; 2036 2037 error = ft_stroke_border_get_counts( stroker->borders + 1, 2038 &count3, &count4 ); 2039 if ( error ) 2040 goto Exit; 2041 2042 num_points = count1 + count3; 2043 num_contours = count2 + count4; 2044 2045 Exit: 2046 if ( anum_points ) 2047 *anum_points = num_points; 2048 2049 if ( anum_contours ) 2050 *anum_contours = num_contours; 2051 2052 return error; 2053 } 2054 2055 2056 /* documentation is in ftstroke.h */ 2057 2058 FT_EXPORT_DEF( void ) FT_Stroker_ExportBorder(FT_Stroker stroker,FT_StrokerBorder border,FT_Outline * outline)2059 FT_Stroker_ExportBorder( FT_Stroker stroker, 2060 FT_StrokerBorder border, 2061 FT_Outline* outline ) 2062 { 2063 if ( !stroker || !outline ) 2064 return; 2065 2066 if ( border == FT_STROKER_BORDER_LEFT || 2067 border == FT_STROKER_BORDER_RIGHT ) 2068 { 2069 FT_StrokeBorder sborder = & stroker->borders[border]; 2070 2071 2072 if ( sborder->valid ) 2073 ft_stroke_border_export( sborder, outline ); 2074 } 2075 } 2076 2077 2078 /* documentation is in ftstroke.h */ 2079 2080 FT_EXPORT_DEF( void ) FT_Stroker_Export(FT_Stroker stroker,FT_Outline * outline)2081 FT_Stroker_Export( FT_Stroker stroker, 2082 FT_Outline* outline ) 2083 { 2084 FT_Stroker_ExportBorder( stroker, FT_STROKER_BORDER_LEFT, outline ); 2085 FT_Stroker_ExportBorder( stroker, FT_STROKER_BORDER_RIGHT, outline ); 2086 } 2087 2088 2089 /* documentation is in ftstroke.h */ 2090 2091 /* 2092 * The following is very similar to FT_Outline_Decompose, except 2093 * that we do support opened paths, and do not scale the outline. 2094 */ 2095 FT_EXPORT_DEF( FT_Error ) FT_Stroker_ParseOutline(FT_Stroker stroker,FT_Outline * outline,FT_Bool opened)2096 FT_Stroker_ParseOutline( FT_Stroker stroker, 2097 FT_Outline* outline, 2098 FT_Bool opened ) 2099 { 2100 FT_Vector v_last; 2101 FT_Vector v_control; 2102 FT_Vector v_start; 2103 2104 FT_Vector* point; 2105 FT_Vector* limit; 2106 char* tags; 2107 2108 FT_Error error; 2109 2110 FT_Int n; /* index of contour in outline */ 2111 FT_UInt first; /* index of first point in contour */ 2112 FT_Int tag; /* current point's state */ 2113 2114 2115 if ( !outline ) 2116 return FT_THROW( Invalid_Outline ); 2117 2118 if ( !stroker ) 2119 return FT_THROW( Invalid_Argument ); 2120 2121 FT_Stroker_Rewind( stroker ); 2122 2123 first = 0; 2124 2125 for ( n = 0; n < outline->n_contours; n++ ) 2126 { 2127 FT_UInt last; /* index of last point in contour */ 2128 2129 2130 last = (FT_UInt)outline->contours[n]; 2131 limit = outline->points + last; 2132 2133 /* skip empty points; we don't stroke these */ 2134 if ( last <= first ) 2135 { 2136 first = last + 1; 2137 continue; 2138 } 2139 2140 v_start = outline->points[first]; 2141 v_last = outline->points[last]; 2142 2143 v_control = v_start; 2144 2145 point = outline->points + first; 2146 tags = outline->tags + first; 2147 tag = FT_CURVE_TAG( tags[0] ); 2148 2149 /* A contour cannot start with a cubic control point! */ 2150 if ( tag == FT_CURVE_TAG_CUBIC ) 2151 goto Invalid_Outline; 2152 2153 /* check first point to determine origin */ 2154 if ( tag == FT_CURVE_TAG_CONIC ) 2155 { 2156 /* First point is conic control. Yes, this happens. */ 2157 if ( FT_CURVE_TAG( outline->tags[last] ) == FT_CURVE_TAG_ON ) 2158 { 2159 /* start at last point if it is on the curve */ 2160 v_start = v_last; 2161 limit--; 2162 } 2163 else 2164 { 2165 /* if both first and last points are conic, */ 2166 /* start at their middle */ 2167 v_start.x = ( v_start.x + v_last.x ) / 2; 2168 v_start.y = ( v_start.y + v_last.y ) / 2; 2169 } 2170 point--; 2171 tags--; 2172 } 2173 2174 error = FT_Stroker_BeginSubPath( stroker, &v_start, opened ); 2175 if ( error ) 2176 goto Exit; 2177 2178 while ( point < limit ) 2179 { 2180 point++; 2181 tags++; 2182 2183 tag = FT_CURVE_TAG( tags[0] ); 2184 switch ( tag ) 2185 { 2186 case FT_CURVE_TAG_ON: /* emit a single line_to */ 2187 { 2188 FT_Vector vec; 2189 2190 2191 vec.x = point->x; 2192 vec.y = point->y; 2193 2194 error = FT_Stroker_LineTo( stroker, &vec ); 2195 if ( error ) 2196 goto Exit; 2197 continue; 2198 } 2199 2200 case FT_CURVE_TAG_CONIC: /* consume conic arcs */ 2201 v_control.x = point->x; 2202 v_control.y = point->y; 2203 2204 Do_Conic: 2205 if ( point < limit ) 2206 { 2207 FT_Vector vec; 2208 FT_Vector v_middle; 2209 2210 2211 point++; 2212 tags++; 2213 tag = FT_CURVE_TAG( tags[0] ); 2214 2215 vec = point[0]; 2216 2217 if ( tag == FT_CURVE_TAG_ON ) 2218 { 2219 error = FT_Stroker_ConicTo( stroker, &v_control, &vec ); 2220 if ( error ) 2221 goto Exit; 2222 continue; 2223 } 2224 2225 if ( tag != FT_CURVE_TAG_CONIC ) 2226 goto Invalid_Outline; 2227 2228 v_middle.x = ( v_control.x + vec.x ) / 2; 2229 v_middle.y = ( v_control.y + vec.y ) / 2; 2230 2231 error = FT_Stroker_ConicTo( stroker, &v_control, &v_middle ); 2232 if ( error ) 2233 goto Exit; 2234 2235 v_control = vec; 2236 goto Do_Conic; 2237 } 2238 2239 error = FT_Stroker_ConicTo( stroker, &v_control, &v_start ); 2240 goto Close; 2241 2242 default: /* FT_CURVE_TAG_CUBIC */ 2243 { 2244 FT_Vector vec1, vec2; 2245 2246 2247 if ( point + 1 > limit || 2248 FT_CURVE_TAG( tags[1] ) != FT_CURVE_TAG_CUBIC ) 2249 goto Invalid_Outline; 2250 2251 point += 2; 2252 tags += 2; 2253 2254 vec1 = point[-2]; 2255 vec2 = point[-1]; 2256 2257 if ( point <= limit ) 2258 { 2259 FT_Vector vec; 2260 2261 2262 vec = point[0]; 2263 2264 error = FT_Stroker_CubicTo( stroker, &vec1, &vec2, &vec ); 2265 if ( error ) 2266 goto Exit; 2267 continue; 2268 } 2269 2270 error = FT_Stroker_CubicTo( stroker, &vec1, &vec2, &v_start ); 2271 goto Close; 2272 } 2273 } 2274 } 2275 2276 Close: 2277 if ( error ) 2278 goto Exit; 2279 2280 /* don't try to end the path if no segments have been generated */ 2281 if ( !stroker->first_point ) 2282 { 2283 error = FT_Stroker_EndSubPath( stroker ); 2284 if ( error ) 2285 goto Exit; 2286 } 2287 2288 first = last + 1; 2289 } 2290 2291 return FT_Err_Ok; 2292 2293 Exit: 2294 return error; 2295 2296 Invalid_Outline: 2297 return FT_THROW( Invalid_Outline ); 2298 } 2299 2300 2301 /* documentation is in ftstroke.h */ 2302 2303 FT_EXPORT_DEF( FT_Error ) FT_Glyph_Stroke(FT_Glyph * pglyph,FT_Stroker stroker,FT_Bool destroy)2304 FT_Glyph_Stroke( FT_Glyph *pglyph, 2305 FT_Stroker stroker, 2306 FT_Bool destroy ) 2307 { 2308 FT_Error error = FT_ERR( Invalid_Argument ); 2309 FT_Glyph glyph = NULL; 2310 2311 2312 if ( !pglyph ) 2313 goto Exit; 2314 2315 glyph = *pglyph; 2316 if ( !glyph || glyph->clazz != &ft_outline_glyph_class ) 2317 goto Exit; 2318 2319 { 2320 FT_Glyph copy; 2321 2322 2323 error = FT_Glyph_Copy( glyph, © ); 2324 if ( error ) 2325 goto Exit; 2326 2327 glyph = copy; 2328 } 2329 2330 { 2331 FT_OutlineGlyph oglyph = (FT_OutlineGlyph)glyph; 2332 FT_Outline* outline = &oglyph->outline; 2333 FT_UInt num_points, num_contours; 2334 2335 2336 error = FT_Stroker_ParseOutline( stroker, outline, FALSE ); 2337 if ( error ) 2338 goto Fail; 2339 2340 FT_Stroker_GetCounts( stroker, &num_points, &num_contours ); 2341 2342 FT_Outline_Done( glyph->library, outline ); 2343 2344 error = FT_Outline_New( glyph->library, 2345 num_points, 2346 (FT_Int)num_contours, 2347 outline ); 2348 if ( error ) 2349 goto Fail; 2350 2351 outline->n_points = 0; 2352 outline->n_contours = 0; 2353 2354 FT_Stroker_Export( stroker, outline ); 2355 } 2356 2357 if ( destroy ) 2358 FT_Done_Glyph( *pglyph ); 2359 2360 *pglyph = glyph; 2361 goto Exit; 2362 2363 Fail: 2364 FT_Done_Glyph( glyph ); 2365 glyph = NULL; 2366 2367 if ( !destroy ) 2368 *pglyph = NULL; 2369 2370 Exit: 2371 return error; 2372 } 2373 2374 2375 /* documentation is in ftstroke.h */ 2376 2377 FT_EXPORT_DEF( FT_Error ) FT_Glyph_StrokeBorder(FT_Glyph * pglyph,FT_Stroker stroker,FT_Bool inside,FT_Bool destroy)2378 FT_Glyph_StrokeBorder( FT_Glyph *pglyph, 2379 FT_Stroker stroker, 2380 FT_Bool inside, 2381 FT_Bool destroy ) 2382 { 2383 FT_Error error = FT_ERR( Invalid_Argument ); 2384 FT_Glyph glyph = NULL; 2385 2386 2387 if ( !pglyph ) 2388 goto Exit; 2389 2390 glyph = *pglyph; 2391 if ( !glyph || glyph->clazz != &ft_outline_glyph_class ) 2392 goto Exit; 2393 2394 { 2395 FT_Glyph copy; 2396 2397 2398 error = FT_Glyph_Copy( glyph, © ); 2399 if ( error ) 2400 goto Exit; 2401 2402 glyph = copy; 2403 } 2404 2405 { 2406 FT_OutlineGlyph oglyph = (FT_OutlineGlyph)glyph; 2407 FT_StrokerBorder border; 2408 FT_Outline* outline = &oglyph->outline; 2409 FT_UInt num_points, num_contours; 2410 2411 2412 border = FT_Outline_GetOutsideBorder( outline ); 2413 if ( inside ) 2414 { 2415 if ( border == FT_STROKER_BORDER_LEFT ) 2416 border = FT_STROKER_BORDER_RIGHT; 2417 else 2418 border = FT_STROKER_BORDER_LEFT; 2419 } 2420 2421 error = FT_Stroker_ParseOutline( stroker, outline, FALSE ); 2422 if ( error ) 2423 goto Fail; 2424 2425 FT_Stroker_GetBorderCounts( stroker, border, 2426 &num_points, &num_contours ); 2427 2428 FT_Outline_Done( glyph->library, outline ); 2429 2430 error = FT_Outline_New( glyph->library, 2431 num_points, 2432 (FT_Int)num_contours, 2433 outline ); 2434 if ( error ) 2435 goto Fail; 2436 2437 outline->n_points = 0; 2438 outline->n_contours = 0; 2439 2440 FT_Stroker_ExportBorder( stroker, border, outline ); 2441 } 2442 2443 if ( destroy ) 2444 FT_Done_Glyph( *pglyph ); 2445 2446 *pglyph = glyph; 2447 goto Exit; 2448 2449 Fail: 2450 FT_Done_Glyph( glyph ); 2451 glyph = NULL; 2452 2453 if ( !destroy ) 2454 *pglyph = NULL; 2455 2456 Exit: 2457 return error; 2458 } 2459 2460 2461 /* END */ 2462