1 /**************************************************************************** 2 * 3 * ftstroke.c 4 * 5 * FreeType path stroker (body). 6 * 7 * Copyright 2002-2018 by 8 * David Turner, Robert Wilhelm, and Werner Lemberg. 9 * 10 * This file is part of the FreeType project, and may only be used, 11 * modified, and distributed under the terms of the FreeType project 12 * license, LICENSE.TXT. By continuing to use, modify, or distribute 13 * this file you indicate that you have read the license and 14 * understand and accept it fully. 15 * 16 */ 17 18 19 #include <ft2build.h> 20 #include FT_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 b = base[1].x; 90 a = base[3].x = ( base[2].x + b ) / 2; 91 b = base[1].x = ( base[0].x + b ) / 2; 92 base[2].x = ( a + b ) / 2; 93 94 base[4].y = base[2].y; 95 b = base[1].y; 96 a = base[3].y = ( base[2].y + b ) / 2; 97 b = base[1].y = ( base[0].y + b ) / 2; 98 base[2].y = ( a + b ) / 2; 99 } 100 101 102 static FT_Bool ft_conic_is_small_enough(FT_Vector * base,FT_Angle * angle_in,FT_Angle * angle_out)103 ft_conic_is_small_enough( FT_Vector* base, 104 FT_Angle *angle_in, 105 FT_Angle *angle_out ) 106 { 107 FT_Vector d1, d2; 108 FT_Angle theta; 109 FT_Int close1, close2; 110 111 112 d1.x = base[1].x - base[2].x; 113 d1.y = base[1].y - base[2].y; 114 d2.x = base[0].x - base[1].x; 115 d2.y = base[0].y - base[1].y; 116 117 close1 = FT_IS_SMALL( d1.x ) && FT_IS_SMALL( d1.y ); 118 close2 = FT_IS_SMALL( d2.x ) && FT_IS_SMALL( d2.y ); 119 120 if ( close1 ) 121 { 122 if ( close2 ) 123 { 124 /* basically a point; */ 125 /* do nothing to retain original direction */ 126 } 127 else 128 { 129 *angle_in = 130 *angle_out = FT_Atan2( d2.x, d2.y ); 131 } 132 } 133 else /* !close1 */ 134 { 135 if ( close2 ) 136 { 137 *angle_in = 138 *angle_out = FT_Atan2( d1.x, d1.y ); 139 } 140 else 141 { 142 *angle_in = FT_Atan2( d1.x, d1.y ); 143 *angle_out = FT_Atan2( d2.x, d2.y ); 144 } 145 } 146 147 theta = ft_pos_abs( FT_Angle_Diff( *angle_in, *angle_out ) ); 148 149 return FT_BOOL( theta < FT_SMALL_CONIC_THRESHOLD ); 150 } 151 152 153 static void ft_cubic_split(FT_Vector * base)154 ft_cubic_split( FT_Vector* base ) 155 { 156 FT_Pos a, b, c, d; 157 158 159 base[6].x = base[3].x; 160 c = base[1].x; 161 d = base[2].x; 162 base[1].x = a = ( base[0].x + c ) / 2; 163 base[5].x = b = ( base[3].x + d ) / 2; 164 c = ( c + d ) / 2; 165 base[2].x = a = ( a + c ) / 2; 166 base[4].x = b = ( b + c ) / 2; 167 base[3].x = ( a + b ) / 2; 168 169 base[6].y = base[3].y; 170 c = base[1].y; 171 d = base[2].y; 172 base[1].y = a = ( base[0].y + c ) / 2; 173 base[5].y = b = ( base[3].y + d ) / 2; 174 c = ( c + d ) / 2; 175 base[2].y = a = ( a + c ) / 2; 176 base[4].y = b = ( b + c ) / 2; 177 base[3].y = ( a + b ) / 2; 178 } 179 180 181 /* Return the average of `angle1' and `angle2'. */ 182 /* This gives correct result even if `angle1' and `angle2' */ 183 /* have opposite signs. */ 184 static FT_Angle ft_angle_mean(FT_Angle angle1,FT_Angle angle2)185 ft_angle_mean( FT_Angle angle1, 186 FT_Angle angle2 ) 187 { 188 return angle1 + FT_Angle_Diff( angle1, angle2 ) / 2; 189 } 190 191 192 static FT_Bool ft_cubic_is_small_enough(FT_Vector * base,FT_Angle * angle_in,FT_Angle * angle_mid,FT_Angle * angle_out)193 ft_cubic_is_small_enough( FT_Vector* base, 194 FT_Angle *angle_in, 195 FT_Angle *angle_mid, 196 FT_Angle *angle_out ) 197 { 198 FT_Vector d1, d2, d3; 199 FT_Angle theta1, theta2; 200 FT_Int close1, close2, close3; 201 202 203 d1.x = base[2].x - base[3].x; 204 d1.y = base[2].y - base[3].y; 205 d2.x = base[1].x - base[2].x; 206 d2.y = base[1].y - base[2].y; 207 d3.x = base[0].x - base[1].x; 208 d3.y = base[0].y - base[1].y; 209 210 close1 = FT_IS_SMALL( d1.x ) && FT_IS_SMALL( d1.y ); 211 close2 = FT_IS_SMALL( d2.x ) && FT_IS_SMALL( d2.y ); 212 close3 = FT_IS_SMALL( d3.x ) && FT_IS_SMALL( d3.y ); 213 214 if ( close1 ) 215 { 216 if ( close2 ) 217 { 218 if ( close3 ) 219 { 220 /* basically a point; */ 221 /* do nothing to retain original direction */ 222 } 223 else /* !close3 */ 224 { 225 *angle_in = 226 *angle_mid = 227 *angle_out = FT_Atan2( d3.x, d3.y ); 228 } 229 } 230 else /* !close2 */ 231 { 232 if ( close3 ) 233 { 234 *angle_in = 235 *angle_mid = 236 *angle_out = FT_Atan2( d2.x, d2.y ); 237 } 238 else /* !close3 */ 239 { 240 *angle_in = 241 *angle_mid = FT_Atan2( d2.x, d2.y ); 242 *angle_out = FT_Atan2( d3.x, d3.y ); 243 } 244 } 245 } 246 else /* !close1 */ 247 { 248 if ( close2 ) 249 { 250 if ( close3 ) 251 { 252 *angle_in = 253 *angle_mid = 254 *angle_out = FT_Atan2( d1.x, d1.y ); 255 } 256 else /* !close3 */ 257 { 258 *angle_in = FT_Atan2( d1.x, d1.y ); 259 *angle_out = FT_Atan2( d3.x, d3.y ); 260 *angle_mid = ft_angle_mean( *angle_in, *angle_out ); 261 } 262 } 263 else /* !close2 */ 264 { 265 if ( close3 ) 266 { 267 *angle_in = FT_Atan2( d1.x, d1.y ); 268 *angle_mid = 269 *angle_out = FT_Atan2( d2.x, d2.y ); 270 } 271 else /* !close3 */ 272 { 273 *angle_in = FT_Atan2( d1.x, d1.y ); 274 *angle_mid = FT_Atan2( d2.x, d2.y ); 275 *angle_out = FT_Atan2( d3.x, d3.y ); 276 } 277 } 278 } 279 280 theta1 = ft_pos_abs( FT_Angle_Diff( *angle_in, *angle_mid ) ); 281 theta2 = ft_pos_abs( FT_Angle_Diff( *angle_mid, *angle_out ) ); 282 283 return FT_BOOL( theta1 < FT_SMALL_CUBIC_THRESHOLD && 284 theta2 < FT_SMALL_CUBIC_THRESHOLD ); 285 } 286 287 288 /*************************************************************************/ 289 /*************************************************************************/ 290 /***** *****/ 291 /***** STROKE BORDERS *****/ 292 /***** *****/ 293 /*************************************************************************/ 294 /*************************************************************************/ 295 296 typedef enum FT_StrokeTags_ 297 { 298 FT_STROKE_TAG_ON = 1, /* on-curve point */ 299 FT_STROKE_TAG_CUBIC = 2, /* cubic off-point */ 300 FT_STROKE_TAG_BEGIN = 4, /* sub-path start */ 301 FT_STROKE_TAG_END = 8 /* sub-path end */ 302 303 } FT_StrokeTags; 304 305 #define FT_STROKE_TAG_BEGIN_END ( FT_STROKE_TAG_BEGIN | FT_STROKE_TAG_END ) 306 307 typedef struct FT_StrokeBorderRec_ 308 { 309 FT_UInt num_points; 310 FT_UInt max_points; 311 FT_Vector* points; 312 FT_Byte* tags; 313 FT_Bool movable; /* TRUE for ends of lineto borders */ 314 FT_Int start; /* index of current sub-path start point */ 315 FT_Memory memory; 316 FT_Bool valid; 317 318 } FT_StrokeBorderRec, *FT_StrokeBorder; 319 320 321 static FT_Error ft_stroke_border_grow(FT_StrokeBorder border,FT_UInt new_points)322 ft_stroke_border_grow( FT_StrokeBorder border, 323 FT_UInt new_points ) 324 { 325 FT_UInt old_max = border->max_points; 326 FT_UInt new_max = border->num_points + new_points; 327 FT_Error error = FT_Err_Ok; 328 329 330 if ( new_max > old_max ) 331 { 332 FT_UInt cur_max = old_max; 333 FT_Memory memory = border->memory; 334 335 336 while ( cur_max < new_max ) 337 cur_max += ( cur_max >> 1 ) + 16; 338 339 if ( FT_RENEW_ARRAY( border->points, old_max, cur_max ) || 340 FT_RENEW_ARRAY( border->tags, old_max, cur_max ) ) 341 goto Exit; 342 343 border->max_points = cur_max; 344 } 345 346 Exit: 347 return error; 348 } 349 350 351 static void ft_stroke_border_close(FT_StrokeBorder border,FT_Bool reverse)352 ft_stroke_border_close( FT_StrokeBorder border, 353 FT_Bool reverse ) 354 { 355 FT_UInt start = (FT_UInt)border->start; 356 FT_UInt count = border->num_points; 357 358 359 FT_ASSERT( border->start >= 0 ); 360 361 /* don't record empty paths! */ 362 if ( count <= start + 1U ) 363 border->num_points = start; 364 else 365 { 366 /* copy the last point to the start of this sub-path, since */ 367 /* it contains the `adjusted' starting coordinates */ 368 border->num_points = --count; 369 border->points[start] = border->points[count]; 370 371 if ( reverse ) 372 { 373 /* reverse the points */ 374 { 375 FT_Vector* vec1 = border->points + start + 1; 376 FT_Vector* vec2 = border->points + count - 1; 377 378 379 for ( ; vec1 < vec2; vec1++, vec2-- ) 380 { 381 FT_Vector tmp; 382 383 384 tmp = *vec1; 385 *vec1 = *vec2; 386 *vec2 = tmp; 387 } 388 } 389 390 /* then the tags */ 391 { 392 FT_Byte* tag1 = border->tags + start + 1; 393 FT_Byte* tag2 = border->tags + count - 1; 394 395 396 for ( ; tag1 < tag2; tag1++, tag2-- ) 397 { 398 FT_Byte tmp; 399 400 401 tmp = *tag1; 402 *tag1 = *tag2; 403 *tag2 = tmp; 404 } 405 } 406 } 407 408 border->tags[start ] |= FT_STROKE_TAG_BEGIN; 409 border->tags[count - 1] |= FT_STROKE_TAG_END; 410 } 411 412 border->start = -1; 413 border->movable = FALSE; 414 } 415 416 417 static FT_Error ft_stroke_border_lineto(FT_StrokeBorder border,FT_Vector * to,FT_Bool movable)418 ft_stroke_border_lineto( FT_StrokeBorder border, 419 FT_Vector* to, 420 FT_Bool movable ) 421 { 422 FT_Error error = FT_Err_Ok; 423 424 425 FT_ASSERT( border->start >= 0 ); 426 427 if ( border->movable ) 428 { 429 /* move last point */ 430 border->points[border->num_points - 1] = *to; 431 } 432 else 433 { 434 /* don't add zero-length lineto */ 435 if ( border->num_points > 0 && 436 FT_IS_SMALL( border->points[border->num_points - 1].x - to->x ) && 437 FT_IS_SMALL( border->points[border->num_points - 1].y - to->y ) ) 438 return error; 439 440 /* add one point */ 441 error = ft_stroke_border_grow( border, 1 ); 442 if ( !error ) 443 { 444 FT_Vector* vec = border->points + border->num_points; 445 FT_Byte* tag = border->tags + border->num_points; 446 447 448 vec[0] = *to; 449 tag[0] = FT_STROKE_TAG_ON; 450 451 border->num_points += 1; 452 } 453 } 454 border->movable = movable; 455 return error; 456 } 457 458 459 static FT_Error ft_stroke_border_conicto(FT_StrokeBorder border,FT_Vector * control,FT_Vector * to)460 ft_stroke_border_conicto( FT_StrokeBorder border, 461 FT_Vector* control, 462 FT_Vector* to ) 463 { 464 FT_Error error; 465 466 467 FT_ASSERT( border->start >= 0 ); 468 469 error = ft_stroke_border_grow( border, 2 ); 470 if ( !error ) 471 { 472 FT_Vector* vec = border->points + border->num_points; 473 FT_Byte* tag = border->tags + border->num_points; 474 475 476 vec[0] = *control; 477 vec[1] = *to; 478 479 tag[0] = 0; 480 tag[1] = FT_STROKE_TAG_ON; 481 482 border->num_points += 2; 483 } 484 485 border->movable = FALSE; 486 487 return error; 488 } 489 490 491 static FT_Error ft_stroke_border_cubicto(FT_StrokeBorder border,FT_Vector * control1,FT_Vector * control2,FT_Vector * to)492 ft_stroke_border_cubicto( FT_StrokeBorder border, 493 FT_Vector* control1, 494 FT_Vector* control2, 495 FT_Vector* to ) 496 { 497 FT_Error error; 498 499 500 FT_ASSERT( border->start >= 0 ); 501 502 error = ft_stroke_border_grow( border, 3 ); 503 if ( !error ) 504 { 505 FT_Vector* vec = border->points + border->num_points; 506 FT_Byte* tag = border->tags + border->num_points; 507 508 509 vec[0] = *control1; 510 vec[1] = *control2; 511 vec[2] = *to; 512 513 tag[0] = FT_STROKE_TAG_CUBIC; 514 tag[1] = FT_STROKE_TAG_CUBIC; 515 tag[2] = FT_STROKE_TAG_ON; 516 517 border->num_points += 3; 518 } 519 520 border->movable = FALSE; 521 522 return error; 523 } 524 525 526 #define FT_ARC_CUBIC_ANGLE ( FT_ANGLE_PI / 2 ) 527 528 529 static FT_Error ft_stroke_border_arcto(FT_StrokeBorder border,FT_Vector * center,FT_Fixed radius,FT_Angle angle_start,FT_Angle angle_diff)530 ft_stroke_border_arcto( FT_StrokeBorder border, 531 FT_Vector* center, 532 FT_Fixed radius, 533 FT_Angle angle_start, 534 FT_Angle angle_diff ) 535 { 536 FT_Angle total, angle, step, rotate, next, theta; 537 FT_Vector a, b, a2, b2; 538 FT_Fixed length; 539 FT_Error error = FT_Err_Ok; 540 541 542 /* compute start point */ 543 FT_Vector_From_Polar( &a, radius, angle_start ); 544 a.x += center->x; 545 a.y += center->y; 546 547 total = angle_diff; 548 angle = angle_start; 549 rotate = ( angle_diff >= 0 ) ? FT_ANGLE_PI2 : -FT_ANGLE_PI2; 550 551 while ( total != 0 ) 552 { 553 step = total; 554 if ( step > FT_ARC_CUBIC_ANGLE ) 555 step = FT_ARC_CUBIC_ANGLE; 556 557 else if ( step < -FT_ARC_CUBIC_ANGLE ) 558 step = -FT_ARC_CUBIC_ANGLE; 559 560 next = angle + step; 561 theta = step; 562 if ( theta < 0 ) 563 theta = -theta; 564 565 theta >>= 1; 566 567 /* compute end point */ 568 FT_Vector_From_Polar( &b, radius, next ); 569 b.x += center->x; 570 b.y += center->y; 571 572 /* compute first and second control points */ 573 length = FT_MulDiv( radius, FT_Sin( theta ) * 4, 574 ( 0x10000L + FT_Cos( theta ) ) * 3 ); 575 576 FT_Vector_From_Polar( &a2, length, angle + rotate ); 577 a2.x += a.x; 578 a2.y += a.y; 579 580 FT_Vector_From_Polar( &b2, length, next - rotate ); 581 b2.x += b.x; 582 b2.y += b.y; 583 584 /* add cubic arc */ 585 error = ft_stroke_border_cubicto( border, &a2, &b2, &b ); 586 if ( error ) 587 break; 588 589 /* process the rest of the arc ?? */ 590 a = b; 591 total -= step; 592 angle = next; 593 } 594 595 return error; 596 } 597 598 599 static FT_Error ft_stroke_border_moveto(FT_StrokeBorder border,FT_Vector * to)600 ft_stroke_border_moveto( FT_StrokeBorder border, 601 FT_Vector* to ) 602 { 603 /* close current open path if any ? */ 604 if ( border->start >= 0 ) 605 ft_stroke_border_close( border, FALSE ); 606 607 border->start = (FT_Int)border->num_points; 608 border->movable = FALSE; 609 610 return ft_stroke_border_lineto( border, to, FALSE ); 611 } 612 613 614 static void ft_stroke_border_init(FT_StrokeBorder border,FT_Memory memory)615 ft_stroke_border_init( FT_StrokeBorder border, 616 FT_Memory memory ) 617 { 618 border->memory = memory; 619 border->points = NULL; 620 border->tags = NULL; 621 622 border->num_points = 0; 623 border->max_points = 0; 624 border->start = -1; 625 border->valid = FALSE; 626 } 627 628 629 static void ft_stroke_border_reset(FT_StrokeBorder border)630 ft_stroke_border_reset( FT_StrokeBorder border ) 631 { 632 border->num_points = 0; 633 border->start = -1; 634 border->valid = FALSE; 635 } 636 637 638 static void ft_stroke_border_done(FT_StrokeBorder border)639 ft_stroke_border_done( FT_StrokeBorder border ) 640 { 641 FT_Memory memory = border->memory; 642 643 644 FT_FREE( border->points ); 645 FT_FREE( border->tags ); 646 647 border->num_points = 0; 648 border->max_points = 0; 649 border->start = -1; 650 border->valid = FALSE; 651 } 652 653 654 static FT_Error ft_stroke_border_get_counts(FT_StrokeBorder border,FT_UInt * anum_points,FT_UInt * anum_contours)655 ft_stroke_border_get_counts( FT_StrokeBorder border, 656 FT_UInt *anum_points, 657 FT_UInt *anum_contours ) 658 { 659 FT_Error error = FT_Err_Ok; 660 FT_UInt num_points = 0; 661 FT_UInt num_contours = 0; 662 663 FT_UInt count = border->num_points; 664 FT_Vector* point = border->points; 665 FT_Byte* tags = border->tags; 666 FT_Int in_contour = 0; 667 668 669 for ( ; count > 0; count--, num_points++, point++, tags++ ) 670 { 671 if ( tags[0] & FT_STROKE_TAG_BEGIN ) 672 { 673 if ( in_contour != 0 ) 674 goto Fail; 675 676 in_contour = 1; 677 } 678 else if ( in_contour == 0 ) 679 goto Fail; 680 681 if ( tags[0] & FT_STROKE_TAG_END ) 682 { 683 in_contour = 0; 684 num_contours++; 685 } 686 } 687 688 if ( in_contour != 0 ) 689 goto Fail; 690 691 border->valid = TRUE; 692 693 Exit: 694 *anum_points = num_points; 695 *anum_contours = num_contours; 696 return error; 697 698 Fail: 699 num_points = 0; 700 num_contours = 0; 701 goto Exit; 702 } 703 704 705 static void ft_stroke_border_export(FT_StrokeBorder border,FT_Outline * outline)706 ft_stroke_border_export( FT_StrokeBorder border, 707 FT_Outline* outline ) 708 { 709 /* copy point locations */ 710 if ( border->num_points ) 711 FT_ARRAY_COPY( outline->points + outline->n_points, 712 border->points, 713 border->num_points ); 714 715 /* copy tags */ 716 { 717 FT_UInt count = border->num_points; 718 FT_Byte* read = border->tags; 719 FT_Byte* write = (FT_Byte*)outline->tags + outline->n_points; 720 721 722 for ( ; count > 0; count--, read++, write++ ) 723 { 724 if ( *read & FT_STROKE_TAG_ON ) 725 *write = FT_CURVE_TAG_ON; 726 else if ( *read & FT_STROKE_TAG_CUBIC ) 727 *write = FT_CURVE_TAG_CUBIC; 728 else 729 *write = FT_CURVE_TAG_CONIC; 730 } 731 } 732 733 /* copy contours */ 734 { 735 FT_UInt count = border->num_points; 736 FT_Byte* tags = border->tags; 737 FT_Short* write = outline->contours + outline->n_contours; 738 FT_Short idx = (FT_Short)outline->n_points; 739 740 741 for ( ; count > 0; count--, tags++, idx++ ) 742 { 743 if ( *tags & FT_STROKE_TAG_END ) 744 { 745 *write++ = idx; 746 outline->n_contours++; 747 } 748 } 749 } 750 751 outline->n_points += (short)border->num_points; 752 753 FT_ASSERT( FT_Outline_Check( outline ) == 0 ); 754 } 755 756 757 /*************************************************************************/ 758 /*************************************************************************/ 759 /***** *****/ 760 /***** STROKER *****/ 761 /***** *****/ 762 /*************************************************************************/ 763 /*************************************************************************/ 764 765 #define FT_SIDE_TO_ROTATE( s ) ( FT_ANGLE_PI2 - (s) * FT_ANGLE_PI ) 766 767 typedef struct FT_StrokerRec_ 768 { 769 FT_Angle angle_in; /* direction into curr join */ 770 FT_Angle angle_out; /* direction out of join */ 771 FT_Vector center; /* current position */ 772 FT_Fixed line_length; /* length of last lineto */ 773 FT_Bool first_point; /* is this the start? */ 774 FT_Bool subpath_open; /* is the subpath open? */ 775 FT_Angle subpath_angle; /* subpath start direction */ 776 FT_Vector subpath_start; /* subpath start position */ 777 FT_Fixed subpath_line_length; /* subpath start lineto len */ 778 FT_Bool handle_wide_strokes; /* use wide strokes logic? */ 779 780 FT_Stroker_LineCap line_cap; 781 FT_Stroker_LineJoin line_join; 782 FT_Stroker_LineJoin line_join_saved; 783 FT_Fixed miter_limit; 784 FT_Fixed radius; 785 786 FT_StrokeBorderRec borders[2]; 787 FT_Library library; 788 789 } FT_StrokerRec; 790 791 792 /* documentation is in ftstroke.h */ 793 794 FT_EXPORT_DEF( FT_Error ) FT_Stroker_New(FT_Library library,FT_Stroker * astroker)795 FT_Stroker_New( FT_Library library, 796 FT_Stroker *astroker ) 797 { 798 FT_Error error; /* assigned in FT_NEW */ 799 FT_Memory memory; 800 FT_Stroker stroker = NULL; 801 802 803 if ( !library ) 804 return FT_THROW( Invalid_Library_Handle ); 805 806 if ( !astroker ) 807 return FT_THROW( Invalid_Argument ); 808 809 memory = library->memory; 810 811 if ( !FT_NEW( stroker ) ) 812 { 813 stroker->library = library; 814 815 ft_stroke_border_init( &stroker->borders[0], memory ); 816 ft_stroke_border_init( &stroker->borders[1], memory ); 817 } 818 819 *astroker = stroker; 820 821 return error; 822 } 823 824 825 /* documentation is in ftstroke.h */ 826 827 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)828 FT_Stroker_Set( FT_Stroker stroker, 829 FT_Fixed radius, 830 FT_Stroker_LineCap line_cap, 831 FT_Stroker_LineJoin line_join, 832 FT_Fixed miter_limit ) 833 { 834 if ( !stroker ) 835 return; 836 837 stroker->radius = radius; 838 stroker->line_cap = line_cap; 839 stroker->line_join = line_join; 840 stroker->miter_limit = miter_limit; 841 842 /* ensure miter limit has sensible value */ 843 if ( stroker->miter_limit < 0x10000L ) 844 stroker->miter_limit = 0x10000L; 845 846 /* save line join style: */ 847 /* line join style can be temporarily changed when stroking curves */ 848 stroker->line_join_saved = line_join; 849 850 FT_Stroker_Rewind( stroker ); 851 } 852 853 854 /* documentation is in ftstroke.h */ 855 856 FT_EXPORT_DEF( void ) FT_Stroker_Rewind(FT_Stroker stroker)857 FT_Stroker_Rewind( FT_Stroker stroker ) 858 { 859 if ( stroker ) 860 { 861 ft_stroke_border_reset( &stroker->borders[0] ); 862 ft_stroke_border_reset( &stroker->borders[1] ); 863 } 864 } 865 866 867 /* documentation is in ftstroke.h */ 868 869 FT_EXPORT_DEF( void ) FT_Stroker_Done(FT_Stroker stroker)870 FT_Stroker_Done( FT_Stroker stroker ) 871 { 872 if ( stroker ) 873 { 874 FT_Memory memory = stroker->library->memory; 875 876 877 ft_stroke_border_done( &stroker->borders[0] ); 878 ft_stroke_border_done( &stroker->borders[1] ); 879 880 stroker->library = NULL; 881 FT_FREE( stroker ); 882 } 883 } 884 885 886 /* create a circular arc at a corner or cap */ 887 static FT_Error ft_stroker_arcto(FT_Stroker stroker,FT_Int side)888 ft_stroker_arcto( FT_Stroker stroker, 889 FT_Int side ) 890 { 891 FT_Angle total, rotate; 892 FT_Fixed radius = stroker->radius; 893 FT_Error error = FT_Err_Ok; 894 FT_StrokeBorder border = stroker->borders + side; 895 896 897 rotate = FT_SIDE_TO_ROTATE( side ); 898 899 total = FT_Angle_Diff( stroker->angle_in, stroker->angle_out ); 900 if ( total == FT_ANGLE_PI ) 901 total = -rotate * 2; 902 903 error = ft_stroke_border_arcto( border, 904 &stroker->center, 905 radius, 906 stroker->angle_in + rotate, 907 total ); 908 border->movable = FALSE; 909 return error; 910 } 911 912 913 /* add a cap at the end of an opened path */ 914 static FT_Error ft_stroker_cap(FT_Stroker stroker,FT_Angle angle,FT_Int side)915 ft_stroker_cap( FT_Stroker stroker, 916 FT_Angle angle, 917 FT_Int side ) 918 { 919 FT_Error error = FT_Err_Ok; 920 921 922 if ( stroker->line_cap == FT_STROKER_LINECAP_ROUND ) 923 { 924 /* add a round cap */ 925 stroker->angle_in = angle; 926 stroker->angle_out = angle + FT_ANGLE_PI; 927 928 error = ft_stroker_arcto( stroker, side ); 929 } 930 else if ( stroker->line_cap == FT_STROKER_LINECAP_SQUARE ) 931 { 932 /* add a square cap */ 933 FT_Vector delta, delta2; 934 FT_Angle rotate = FT_SIDE_TO_ROTATE( side ); 935 FT_Fixed radius = stroker->radius; 936 FT_StrokeBorder border = stroker->borders + side; 937 938 939 FT_Vector_From_Polar( &delta2, radius, angle + rotate ); 940 FT_Vector_From_Polar( &delta, radius, angle ); 941 942 delta.x += stroker->center.x + delta2.x; 943 delta.y += stroker->center.y + delta2.y; 944 945 error = ft_stroke_border_lineto( border, &delta, FALSE ); 946 if ( error ) 947 goto Exit; 948 949 FT_Vector_From_Polar( &delta2, radius, angle - rotate ); 950 FT_Vector_From_Polar( &delta, radius, angle ); 951 952 delta.x += delta2.x + stroker->center.x; 953 delta.y += delta2.y + stroker->center.y; 954 955 error = ft_stroke_border_lineto( border, &delta, FALSE ); 956 } 957 else if ( stroker->line_cap == FT_STROKER_LINECAP_BUTT ) 958 { 959 /* add a butt ending */ 960 FT_Vector delta; 961 FT_Angle rotate = FT_SIDE_TO_ROTATE( side ); 962 FT_Fixed radius = stroker->radius; 963 FT_StrokeBorder border = stroker->borders + side; 964 965 966 FT_Vector_From_Polar( &delta, radius, angle + rotate ); 967 968 delta.x += stroker->center.x; 969 delta.y += stroker->center.y; 970 971 error = ft_stroke_border_lineto( border, &delta, FALSE ); 972 if ( error ) 973 goto Exit; 974 975 FT_Vector_From_Polar( &delta, radius, angle - rotate ); 976 977 delta.x += stroker->center.x; 978 delta.y += stroker->center.y; 979 980 error = ft_stroke_border_lineto( border, &delta, FALSE ); 981 } 982 983 Exit: 984 return error; 985 } 986 987 988 /* process an inside corner, i.e. compute intersection */ 989 static FT_Error ft_stroker_inside(FT_Stroker stroker,FT_Int side,FT_Fixed line_length)990 ft_stroker_inside( FT_Stroker stroker, 991 FT_Int side, 992 FT_Fixed line_length ) 993 { 994 FT_StrokeBorder border = stroker->borders + side; 995 FT_Angle phi, theta, rotate; 996 FT_Fixed length, thcos; 997 FT_Vector delta; 998 FT_Error error = FT_Err_Ok; 999 FT_Bool intersect; /* use intersection of lines? */ 1000 1001 1002 rotate = FT_SIDE_TO_ROTATE( side ); 1003 1004 theta = FT_Angle_Diff( stroker->angle_in, stroker->angle_out ) / 2; 1005 1006 /* Only intersect borders if between two lineto's and both */ 1007 /* lines are long enough (line_length is zero for curves). */ 1008 /* Also avoid U-turns of nearly 180 degree. */ 1009 if ( !border->movable || line_length == 0 || 1010 theta > 0x59C000 || theta < -0x59C000 ) 1011 intersect = FALSE; 1012 else 1013 { 1014 /* compute minimum required length of lines */ 1015 FT_Fixed min_length = ft_pos_abs( FT_MulFix( stroker->radius, 1016 FT_Tan( theta ) ) ); 1017 1018 1019 intersect = FT_BOOL( min_length && 1020 stroker->line_length >= min_length && 1021 line_length >= min_length ); 1022 } 1023 1024 if ( !intersect ) 1025 { 1026 FT_Vector_From_Polar( &delta, stroker->radius, 1027 stroker->angle_out + rotate ); 1028 delta.x += stroker->center.x; 1029 delta.y += stroker->center.y; 1030 1031 border->movable = FALSE; 1032 } 1033 else 1034 { 1035 /* compute median angle */ 1036 phi = stroker->angle_in + theta; 1037 1038 thcos = FT_Cos( theta ); 1039 1040 length = FT_DivFix( stroker->radius, thcos ); 1041 1042 FT_Vector_From_Polar( &delta, length, phi + rotate ); 1043 delta.x += stroker->center.x; 1044 delta.y += stroker->center.y; 1045 } 1046 1047 error = ft_stroke_border_lineto( border, &delta, FALSE ); 1048 1049 return error; 1050 } 1051 1052 1053 /* process an outside corner, i.e. compute bevel/miter/round */ 1054 static FT_Error ft_stroker_outside(FT_Stroker stroker,FT_Int side,FT_Fixed line_length)1055 ft_stroker_outside( FT_Stroker stroker, 1056 FT_Int side, 1057 FT_Fixed line_length ) 1058 { 1059 FT_StrokeBorder border = stroker->borders + side; 1060 FT_Error error; 1061 FT_Angle rotate; 1062 1063 1064 if ( stroker->line_join == FT_STROKER_LINEJOIN_ROUND ) 1065 error = ft_stroker_arcto( stroker, side ); 1066 else 1067 { 1068 /* this is a mitered (pointed) or beveled (truncated) corner */ 1069 FT_Fixed sigma = 0, radius = stroker->radius; 1070 FT_Angle theta = 0, phi = 0; 1071 FT_Fixed thcos = 0; 1072 FT_Bool bevel, fixed_bevel; 1073 1074 1075 rotate = FT_SIDE_TO_ROTATE( side ); 1076 1077 bevel = 1078 FT_BOOL( stroker->line_join == FT_STROKER_LINEJOIN_BEVEL ); 1079 1080 fixed_bevel = 1081 FT_BOOL( stroker->line_join != FT_STROKER_LINEJOIN_MITER_VARIABLE ); 1082 1083 if ( !bevel ) 1084 { 1085 theta = FT_Angle_Diff( stroker->angle_in, stroker->angle_out ); 1086 1087 if ( theta == FT_ANGLE_PI ) 1088 { 1089 theta = rotate; 1090 phi = stroker->angle_in; 1091 } 1092 else 1093 { 1094 theta /= 2; 1095 phi = stroker->angle_in + theta + rotate; 1096 } 1097 1098 thcos = FT_Cos( theta ); 1099 sigma = FT_MulFix( stroker->miter_limit, thcos ); 1100 1101 /* is miter limit exceeded? */ 1102 if ( sigma < 0x10000L ) 1103 { 1104 /* don't create variable bevels for very small deviations; */ 1105 /* FT_Sin(x) = 0 for x <= 57 */ 1106 if ( fixed_bevel || ft_pos_abs( theta ) > 57 ) 1107 bevel = TRUE; 1108 } 1109 } 1110 1111 if ( bevel ) /* this is a bevel (broken angle) */ 1112 { 1113 if ( fixed_bevel ) 1114 { 1115 /* the outer corners are simply joined together */ 1116 FT_Vector delta; 1117 1118 1119 /* add bevel */ 1120 FT_Vector_From_Polar( &delta, 1121 radius, 1122 stroker->angle_out + rotate ); 1123 delta.x += stroker->center.x; 1124 delta.y += stroker->center.y; 1125 1126 border->movable = FALSE; 1127 error = ft_stroke_border_lineto( border, &delta, FALSE ); 1128 } 1129 else /* variable bevel */ 1130 { 1131 /* the miter is truncated */ 1132 FT_Vector middle, delta; 1133 FT_Fixed length; 1134 1135 1136 /* compute middle point */ 1137 FT_Vector_From_Polar( &middle, 1138 FT_MulFix( radius, stroker->miter_limit ), 1139 phi ); 1140 middle.x += stroker->center.x; 1141 middle.y += stroker->center.y; 1142 1143 /* compute first angle point */ 1144 length = FT_MulDiv( radius, 0x10000L - sigma, 1145 ft_pos_abs( FT_Sin( theta ) ) ); 1146 1147 FT_Vector_From_Polar( &delta, length, phi + rotate ); 1148 delta.x += middle.x; 1149 delta.y += middle.y; 1150 1151 error = ft_stroke_border_lineto( border, &delta, FALSE ); 1152 if ( error ) 1153 goto Exit; 1154 1155 /* compute second angle point */ 1156 FT_Vector_From_Polar( &delta, length, phi - rotate ); 1157 delta.x += middle.x; 1158 delta.y += middle.y; 1159 1160 error = ft_stroke_border_lineto( border, &delta, FALSE ); 1161 if ( error ) 1162 goto Exit; 1163 1164 /* finally, add an end point; only needed if not lineto */ 1165 /* (line_length is zero for curves) */ 1166 if ( line_length == 0 ) 1167 { 1168 FT_Vector_From_Polar( &delta, 1169 radius, 1170 stroker->angle_out + rotate ); 1171 1172 delta.x += stroker->center.x; 1173 delta.y += stroker->center.y; 1174 1175 error = ft_stroke_border_lineto( border, &delta, FALSE ); 1176 } 1177 } 1178 } 1179 else /* this is a miter (intersection) */ 1180 { 1181 FT_Fixed length; 1182 FT_Vector delta; 1183 1184 1185 length = FT_DivFix( stroker->radius, thcos ); 1186 1187 FT_Vector_From_Polar( &delta, length, phi ); 1188 delta.x += stroker->center.x; 1189 delta.y += stroker->center.y; 1190 1191 error = ft_stroke_border_lineto( border, &delta, FALSE ); 1192 if ( error ) 1193 goto Exit; 1194 1195 /* now add an end point; only needed if not lineto */ 1196 /* (line_length is zero for curves) */ 1197 if ( line_length == 0 ) 1198 { 1199 FT_Vector_From_Polar( &delta, 1200 stroker->radius, 1201 stroker->angle_out + rotate ); 1202 delta.x += stroker->center.x; 1203 delta.y += stroker->center.y; 1204 1205 error = ft_stroke_border_lineto( border, &delta, FALSE ); 1206 } 1207 } 1208 } 1209 1210 Exit: 1211 return error; 1212 } 1213 1214 1215 static FT_Error ft_stroker_process_corner(FT_Stroker stroker,FT_Fixed line_length)1216 ft_stroker_process_corner( FT_Stroker stroker, 1217 FT_Fixed line_length ) 1218 { 1219 FT_Error error = FT_Err_Ok; 1220 FT_Angle turn; 1221 FT_Int inside_side; 1222 1223 1224 turn = FT_Angle_Diff( stroker->angle_in, stroker->angle_out ); 1225 1226 /* no specific corner processing is required if the turn is 0 */ 1227 if ( turn == 0 ) 1228 goto Exit; 1229 1230 /* when we turn to the right, the inside side is 0 */ 1231 /* otherwise, the inside side is 1 */ 1232 inside_side = ( turn < 0 ); 1233 1234 /* process the inside side */ 1235 error = ft_stroker_inside( stroker, inside_side, line_length ); 1236 if ( error ) 1237 goto Exit; 1238 1239 /* process the outside side */ 1240 error = ft_stroker_outside( stroker, !inside_side, line_length ); 1241 1242 Exit: 1243 return error; 1244 } 1245 1246 1247 /* add two points to the left and right borders corresponding to the */ 1248 /* start of the subpath */ 1249 static FT_Error ft_stroker_subpath_start(FT_Stroker stroker,FT_Angle start_angle,FT_Fixed line_length)1250 ft_stroker_subpath_start( FT_Stroker stroker, 1251 FT_Angle start_angle, 1252 FT_Fixed line_length ) 1253 { 1254 FT_Vector delta; 1255 FT_Vector point; 1256 FT_Error error; 1257 FT_StrokeBorder border; 1258 1259 1260 FT_Vector_From_Polar( &delta, stroker->radius, 1261 start_angle + FT_ANGLE_PI2 ); 1262 1263 point.x = stroker->center.x + delta.x; 1264 point.y = stroker->center.y + delta.y; 1265 1266 border = stroker->borders; 1267 error = ft_stroke_border_moveto( border, &point ); 1268 if ( error ) 1269 goto Exit; 1270 1271 point.x = stroker->center.x - delta.x; 1272 point.y = stroker->center.y - delta.y; 1273 1274 border++; 1275 error = ft_stroke_border_moveto( border, &point ); 1276 1277 /* save angle, position, and line length for last join */ 1278 /* (line_length is zero for curves) */ 1279 stroker->subpath_angle = start_angle; 1280 stroker->first_point = FALSE; 1281 stroker->subpath_line_length = line_length; 1282 1283 Exit: 1284 return error; 1285 } 1286 1287 1288 /* documentation is in ftstroke.h */ 1289 1290 FT_EXPORT_DEF( FT_Error ) FT_Stroker_LineTo(FT_Stroker stroker,FT_Vector * to)1291 FT_Stroker_LineTo( FT_Stroker stroker, 1292 FT_Vector* to ) 1293 { 1294 FT_Error error = FT_Err_Ok; 1295 FT_StrokeBorder border; 1296 FT_Vector delta; 1297 FT_Angle angle; 1298 FT_Int side; 1299 FT_Fixed line_length; 1300 1301 1302 if ( !stroker || !to ) 1303 return FT_THROW( Invalid_Argument ); 1304 1305 delta.x = to->x - stroker->center.x; 1306 delta.y = to->y - stroker->center.y; 1307 1308 /* a zero-length lineto is a no-op; avoid creating a spurious corner */ 1309 if ( delta.x == 0 && delta.y == 0 ) 1310 goto Exit; 1311 1312 /* compute length of line */ 1313 line_length = FT_Vector_Length( &delta ); 1314 1315 angle = FT_Atan2( delta.x, delta.y ); 1316 FT_Vector_From_Polar( &delta, stroker->radius, angle + FT_ANGLE_PI2 ); 1317 1318 /* process corner if necessary */ 1319 if ( stroker->first_point ) 1320 { 1321 /* This is the first segment of a subpath. We need to */ 1322 /* add a point to each border at their respective starting */ 1323 /* point locations. */ 1324 error = ft_stroker_subpath_start( stroker, angle, line_length ); 1325 if ( error ) 1326 goto Exit; 1327 } 1328 else 1329 { 1330 /* process the current corner */ 1331 stroker->angle_out = angle; 1332 error = ft_stroker_process_corner( stroker, line_length ); 1333 if ( error ) 1334 goto Exit; 1335 } 1336 1337 /* now add a line segment to both the `inside' and `outside' paths */ 1338 for ( border = stroker->borders, side = 1; side >= 0; side--, border++ ) 1339 { 1340 FT_Vector point; 1341 1342 1343 point.x = to->x + delta.x; 1344 point.y = to->y + delta.y; 1345 1346 /* the ends of lineto borders are movable */ 1347 error = ft_stroke_border_lineto( border, &point, TRUE ); 1348 if ( error ) 1349 goto Exit; 1350 1351 delta.x = -delta.x; 1352 delta.y = -delta.y; 1353 } 1354 1355 stroker->angle_in = angle; 1356 stroker->center = *to; 1357 stroker->line_length = line_length; 1358 1359 Exit: 1360 return error; 1361 } 1362 1363 1364 /* documentation is in ftstroke.h */ 1365 1366 FT_EXPORT_DEF( FT_Error ) FT_Stroker_ConicTo(FT_Stroker stroker,FT_Vector * control,FT_Vector * to)1367 FT_Stroker_ConicTo( FT_Stroker stroker, 1368 FT_Vector* control, 1369 FT_Vector* to ) 1370 { 1371 FT_Error error = FT_Err_Ok; 1372 FT_Vector bez_stack[34]; 1373 FT_Vector* arc; 1374 FT_Vector* limit = bez_stack + 30; 1375 FT_Bool first_arc = TRUE; 1376 1377 1378 if ( !stroker || !control || !to ) 1379 { 1380 error = FT_THROW( Invalid_Argument ); 1381 goto Exit; 1382 } 1383 1384 /* if all control points are coincident, this is a no-op; */ 1385 /* avoid creating a spurious corner */ 1386 if ( FT_IS_SMALL( stroker->center.x - control->x ) && 1387 FT_IS_SMALL( stroker->center.y - control->y ) && 1388 FT_IS_SMALL( control->x - to->x ) && 1389 FT_IS_SMALL( control->y - to->y ) ) 1390 { 1391 stroker->center = *to; 1392 goto Exit; 1393 } 1394 1395 arc = bez_stack; 1396 arc[0] = *to; 1397 arc[1] = *control; 1398 arc[2] = stroker->center; 1399 1400 while ( arc >= bez_stack ) 1401 { 1402 FT_Angle angle_in, angle_out; 1403 1404 1405 /* initialize with current direction */ 1406 angle_in = angle_out = stroker->angle_in; 1407 1408 if ( arc < limit && 1409 !ft_conic_is_small_enough( arc, &angle_in, &angle_out ) ) 1410 { 1411 if ( stroker->first_point ) 1412 stroker->angle_in = angle_in; 1413 1414 ft_conic_split( arc ); 1415 arc += 2; 1416 continue; 1417 } 1418 1419 if ( first_arc ) 1420 { 1421 first_arc = FALSE; 1422 1423 /* process corner if necessary */ 1424 if ( stroker->first_point ) 1425 error = ft_stroker_subpath_start( stroker, angle_in, 0 ); 1426 else 1427 { 1428 stroker->angle_out = angle_in; 1429 error = ft_stroker_process_corner( stroker, 0 ); 1430 } 1431 } 1432 else if ( ft_pos_abs( FT_Angle_Diff( stroker->angle_in, angle_in ) ) > 1433 FT_SMALL_CONIC_THRESHOLD / 4 ) 1434 { 1435 /* if the deviation from one arc to the next is too great, */ 1436 /* add a round corner */ 1437 stroker->center = arc[2]; 1438 stroker->angle_out = angle_in; 1439 stroker->line_join = FT_STROKER_LINEJOIN_ROUND; 1440 1441 error = ft_stroker_process_corner( stroker, 0 ); 1442 1443 /* reinstate line join style */ 1444 stroker->line_join = stroker->line_join_saved; 1445 } 1446 1447 if ( error ) 1448 goto Exit; 1449 1450 /* the arc's angle is small enough; we can add it directly to each */ 1451 /* border */ 1452 { 1453 FT_Vector ctrl, end; 1454 FT_Angle theta, phi, rotate, alpha0 = 0; 1455 FT_Fixed length; 1456 FT_StrokeBorder border; 1457 FT_Int side; 1458 1459 1460 theta = FT_Angle_Diff( angle_in, angle_out ) / 2; 1461 phi = angle_in + theta; 1462 length = FT_DivFix( stroker->radius, FT_Cos( theta ) ); 1463 1464 /* compute direction of original arc */ 1465 if ( stroker->handle_wide_strokes ) 1466 alpha0 = FT_Atan2( arc[0].x - arc[2].x, arc[0].y - arc[2].y ); 1467 1468 for ( border = stroker->borders, side = 0; 1469 side <= 1; 1470 side++, border++ ) 1471 { 1472 rotate = FT_SIDE_TO_ROTATE( side ); 1473 1474 /* compute control point */ 1475 FT_Vector_From_Polar( &ctrl, length, phi + rotate ); 1476 ctrl.x += arc[1].x; 1477 ctrl.y += arc[1].y; 1478 1479 /* compute end point */ 1480 FT_Vector_From_Polar( &end, stroker->radius, angle_out + rotate ); 1481 end.x += arc[0].x; 1482 end.y += arc[0].y; 1483 1484 if ( stroker->handle_wide_strokes ) 1485 { 1486 FT_Vector start; 1487 FT_Angle alpha1; 1488 1489 1490 /* determine whether the border radius is greater than the */ 1491 /* radius of curvature of the original arc */ 1492 start = border->points[border->num_points - 1]; 1493 1494 alpha1 = FT_Atan2( end.x - start.x, end.y - start.y ); 1495 1496 /* is the direction of the border arc opposite to */ 1497 /* that of the original arc? */ 1498 if ( ft_pos_abs( FT_Angle_Diff( alpha0, alpha1 ) ) > 1499 FT_ANGLE_PI / 2 ) 1500 { 1501 FT_Angle beta, gamma; 1502 FT_Vector bvec, delta; 1503 FT_Fixed blen, sinA, sinB, alen; 1504 1505 1506 /* use the sine rule to find the intersection point */ 1507 beta = FT_Atan2( arc[2].x - start.x, arc[2].y - start.y ); 1508 gamma = FT_Atan2( arc[0].x - end.x, arc[0].y - end.y ); 1509 1510 bvec.x = end.x - start.x; 1511 bvec.y = end.y - start.y; 1512 1513 blen = FT_Vector_Length( &bvec ); 1514 1515 sinA = ft_pos_abs( FT_Sin( alpha1 - gamma ) ); 1516 sinB = ft_pos_abs( FT_Sin( beta - gamma ) ); 1517 1518 alen = FT_MulDiv( blen, sinA, sinB ); 1519 1520 FT_Vector_From_Polar( &delta, alen, beta ); 1521 delta.x += start.x; 1522 delta.y += start.y; 1523 1524 /* circumnavigate the negative sector backwards */ 1525 border->movable = FALSE; 1526 error = ft_stroke_border_lineto( border, &delta, FALSE ); 1527 if ( error ) 1528 goto Exit; 1529 error = ft_stroke_border_lineto( border, &end, FALSE ); 1530 if ( error ) 1531 goto Exit; 1532 error = ft_stroke_border_conicto( border, &ctrl, &start ); 1533 if ( error ) 1534 goto Exit; 1535 /* and then move to the endpoint */ 1536 error = ft_stroke_border_lineto( border, &end, FALSE ); 1537 if ( error ) 1538 goto Exit; 1539 1540 continue; 1541 } 1542 1543 /* else fall through */ 1544 } 1545 1546 /* simply add an arc */ 1547 error = ft_stroke_border_conicto( border, &ctrl, &end ); 1548 if ( error ) 1549 goto Exit; 1550 } 1551 } 1552 1553 arc -= 2; 1554 1555 stroker->angle_in = angle_out; 1556 } 1557 1558 stroker->center = *to; 1559 1560 Exit: 1561 return error; 1562 } 1563 1564 1565 /* documentation is in ftstroke.h */ 1566 1567 FT_EXPORT_DEF( FT_Error ) FT_Stroker_CubicTo(FT_Stroker stroker,FT_Vector * control1,FT_Vector * control2,FT_Vector * to)1568 FT_Stroker_CubicTo( FT_Stroker stroker, 1569 FT_Vector* control1, 1570 FT_Vector* control2, 1571 FT_Vector* to ) 1572 { 1573 FT_Error error = FT_Err_Ok; 1574 FT_Vector bez_stack[37]; 1575 FT_Vector* arc; 1576 FT_Vector* limit = bez_stack + 32; 1577 FT_Bool first_arc = TRUE; 1578 1579 1580 if ( !stroker || !control1 || !control2 || !to ) 1581 { 1582 error = FT_THROW( Invalid_Argument ); 1583 goto Exit; 1584 } 1585 1586 /* if all control points are coincident, this is a no-op; */ 1587 /* avoid creating a spurious corner */ 1588 if ( FT_IS_SMALL( stroker->center.x - control1->x ) && 1589 FT_IS_SMALL( stroker->center.y - control1->y ) && 1590 FT_IS_SMALL( control1->x - control2->x ) && 1591 FT_IS_SMALL( control1->y - control2->y ) && 1592 FT_IS_SMALL( control2->x - to->x ) && 1593 FT_IS_SMALL( control2->y - to->y ) ) 1594 { 1595 stroker->center = *to; 1596 goto Exit; 1597 } 1598 1599 arc = bez_stack; 1600 arc[0] = *to; 1601 arc[1] = *control2; 1602 arc[2] = *control1; 1603 arc[3] = stroker->center; 1604 1605 while ( arc >= bez_stack ) 1606 { 1607 FT_Angle angle_in, angle_mid, angle_out; 1608 1609 1610 /* initialize with current direction */ 1611 angle_in = angle_out = angle_mid = stroker->angle_in; 1612 1613 if ( arc < limit && 1614 !ft_cubic_is_small_enough( arc, &angle_in, 1615 &angle_mid, &angle_out ) ) 1616 { 1617 if ( stroker->first_point ) 1618 stroker->angle_in = angle_in; 1619 1620 ft_cubic_split( arc ); 1621 arc += 3; 1622 continue; 1623 } 1624 1625 if ( first_arc ) 1626 { 1627 first_arc = FALSE; 1628 1629 /* process corner if necessary */ 1630 if ( stroker->first_point ) 1631 error = ft_stroker_subpath_start( stroker, angle_in, 0 ); 1632 else 1633 { 1634 stroker->angle_out = angle_in; 1635 error = ft_stroker_process_corner( stroker, 0 ); 1636 } 1637 } 1638 else if ( ft_pos_abs( FT_Angle_Diff( stroker->angle_in, angle_in ) ) > 1639 FT_SMALL_CUBIC_THRESHOLD / 4 ) 1640 { 1641 /* if the deviation from one arc to the next is too great, */ 1642 /* add a round corner */ 1643 stroker->center = arc[3]; 1644 stroker->angle_out = angle_in; 1645 stroker->line_join = FT_STROKER_LINEJOIN_ROUND; 1646 1647 error = ft_stroker_process_corner( stroker, 0 ); 1648 1649 /* reinstate line join style */ 1650 stroker->line_join = stroker->line_join_saved; 1651 } 1652 1653 if ( error ) 1654 goto Exit; 1655 1656 /* the arc's angle is small enough; we can add it directly to each */ 1657 /* border */ 1658 { 1659 FT_Vector ctrl1, ctrl2, end; 1660 FT_Angle theta1, phi1, theta2, phi2, rotate, alpha0 = 0; 1661 FT_Fixed length1, length2; 1662 FT_StrokeBorder border; 1663 FT_Int side; 1664 1665 1666 theta1 = FT_Angle_Diff( angle_in, angle_mid ) / 2; 1667 theta2 = FT_Angle_Diff( angle_mid, angle_out ) / 2; 1668 phi1 = ft_angle_mean( angle_in, angle_mid ); 1669 phi2 = ft_angle_mean( angle_mid, angle_out ); 1670 length1 = FT_DivFix( stroker->radius, FT_Cos( theta1 ) ); 1671 length2 = FT_DivFix( stroker->radius, FT_Cos( theta2 ) ); 1672 1673 /* compute direction of original arc */ 1674 if ( stroker->handle_wide_strokes ) 1675 alpha0 = FT_Atan2( arc[0].x - arc[3].x, arc[0].y - arc[3].y ); 1676 1677 for ( border = stroker->borders, side = 0; 1678 side <= 1; 1679 side++, border++ ) 1680 { 1681 rotate = FT_SIDE_TO_ROTATE( side ); 1682 1683 /* compute control points */ 1684 FT_Vector_From_Polar( &ctrl1, length1, phi1 + rotate ); 1685 ctrl1.x += arc[2].x; 1686 ctrl1.y += arc[2].y; 1687 1688 FT_Vector_From_Polar( &ctrl2, length2, phi2 + rotate ); 1689 ctrl2.x += arc[1].x; 1690 ctrl2.y += arc[1].y; 1691 1692 /* compute end point */ 1693 FT_Vector_From_Polar( &end, stroker->radius, angle_out + rotate ); 1694 end.x += arc[0].x; 1695 end.y += arc[0].y; 1696 1697 if ( stroker->handle_wide_strokes ) 1698 { 1699 FT_Vector start; 1700 FT_Angle alpha1; 1701 1702 1703 /* determine whether the border radius is greater than the */ 1704 /* radius of curvature of the original arc */ 1705 start = border->points[border->num_points - 1]; 1706 1707 alpha1 = FT_Atan2( end.x - start.x, end.y - start.y ); 1708 1709 /* is the direction of the border arc opposite to */ 1710 /* that of the original arc? */ 1711 if ( ft_pos_abs( FT_Angle_Diff( alpha0, alpha1 ) ) > 1712 FT_ANGLE_PI / 2 ) 1713 { 1714 FT_Angle beta, gamma; 1715 FT_Vector bvec, delta; 1716 FT_Fixed blen, sinA, sinB, alen; 1717 1718 1719 /* use the sine rule to find the intersection point */ 1720 beta = FT_Atan2( arc[3].x - start.x, arc[3].y - start.y ); 1721 gamma = FT_Atan2( arc[0].x - end.x, arc[0].y - end.y ); 1722 1723 bvec.x = end.x - start.x; 1724 bvec.y = end.y - start.y; 1725 1726 blen = FT_Vector_Length( &bvec ); 1727 1728 sinA = ft_pos_abs( FT_Sin( alpha1 - gamma ) ); 1729 sinB = ft_pos_abs( FT_Sin( beta - gamma ) ); 1730 1731 alen = FT_MulDiv( blen, sinA, sinB ); 1732 1733 FT_Vector_From_Polar( &delta, alen, beta ); 1734 delta.x += start.x; 1735 delta.y += start.y; 1736 1737 /* circumnavigate the negative sector backwards */ 1738 border->movable = FALSE; 1739 error = ft_stroke_border_lineto( border, &delta, FALSE ); 1740 if ( error ) 1741 goto Exit; 1742 error = ft_stroke_border_lineto( border, &end, FALSE ); 1743 if ( error ) 1744 goto Exit; 1745 error = ft_stroke_border_cubicto( border, 1746 &ctrl2, 1747 &ctrl1, 1748 &start ); 1749 if ( error ) 1750 goto Exit; 1751 /* and then move to the endpoint */ 1752 error = ft_stroke_border_lineto( border, &end, FALSE ); 1753 if ( error ) 1754 goto Exit; 1755 1756 continue; 1757 } 1758 1759 /* else fall through */ 1760 } 1761 1762 /* simply add an arc */ 1763 error = ft_stroke_border_cubicto( border, &ctrl1, &ctrl2, &end ); 1764 if ( error ) 1765 goto Exit; 1766 } 1767 } 1768 1769 arc -= 3; 1770 1771 stroker->angle_in = angle_out; 1772 } 1773 1774 stroker->center = *to; 1775 1776 Exit: 1777 return error; 1778 } 1779 1780 1781 /* documentation is in ftstroke.h */ 1782 1783 FT_EXPORT_DEF( FT_Error ) FT_Stroker_BeginSubPath(FT_Stroker stroker,FT_Vector * to,FT_Bool open)1784 FT_Stroker_BeginSubPath( FT_Stroker stroker, 1785 FT_Vector* to, 1786 FT_Bool open ) 1787 { 1788 if ( !stroker || !to ) 1789 return FT_THROW( Invalid_Argument ); 1790 1791 /* We cannot process the first point, because there is not enough */ 1792 /* information regarding its corner/cap. The latter will be processed */ 1793 /* in the `FT_Stroker_EndSubPath' routine. */ 1794 /* */ 1795 stroker->first_point = TRUE; 1796 stroker->center = *to; 1797 stroker->subpath_open = open; 1798 1799 /* Determine if we need to check whether the border radius is greater */ 1800 /* than the radius of curvature of a curve, to handle this case */ 1801 /* specially. This is only required if bevel joins or butt caps may */ 1802 /* be created, because round & miter joins and round & square caps */ 1803 /* cover the negative sector created with wide strokes. */ 1804 stroker->handle_wide_strokes = 1805 FT_BOOL( stroker->line_join != FT_STROKER_LINEJOIN_ROUND || 1806 ( stroker->subpath_open && 1807 stroker->line_cap == FT_STROKER_LINECAP_BUTT ) ); 1808 1809 /* record the subpath start point for each border */ 1810 stroker->subpath_start = *to; 1811 1812 stroker->angle_in = 0; 1813 1814 return FT_Err_Ok; 1815 } 1816 1817 1818 static FT_Error ft_stroker_add_reverse_left(FT_Stroker stroker,FT_Bool open)1819 ft_stroker_add_reverse_left( FT_Stroker stroker, 1820 FT_Bool open ) 1821 { 1822 FT_StrokeBorder right = stroker->borders + 0; 1823 FT_StrokeBorder left = stroker->borders + 1; 1824 FT_Int new_points; 1825 FT_Error error = FT_Err_Ok; 1826 1827 1828 FT_ASSERT( left->start >= 0 ); 1829 1830 new_points = (FT_Int)left->num_points - left->start; 1831 if ( new_points > 0 ) 1832 { 1833 error = ft_stroke_border_grow( right, (FT_UInt)new_points ); 1834 if ( error ) 1835 goto Exit; 1836 1837 { 1838 FT_Vector* dst_point = right->points + right->num_points; 1839 FT_Byte* dst_tag = right->tags + right->num_points; 1840 FT_Vector* src_point = left->points + left->num_points - 1; 1841 FT_Byte* src_tag = left->tags + left->num_points - 1; 1842 1843 1844 while ( src_point >= left->points + left->start ) 1845 { 1846 *dst_point = *src_point; 1847 *dst_tag = *src_tag; 1848 1849 if ( open ) 1850 dst_tag[0] &= ~FT_STROKE_TAG_BEGIN_END; 1851 else 1852 { 1853 FT_Byte ttag = 1854 (FT_Byte)( dst_tag[0] & FT_STROKE_TAG_BEGIN_END ); 1855 1856 1857 /* switch begin/end tags if necessary */ 1858 if ( ttag == FT_STROKE_TAG_BEGIN || 1859 ttag == FT_STROKE_TAG_END ) 1860 dst_tag[0] ^= FT_STROKE_TAG_BEGIN_END; 1861 } 1862 1863 src_point--; 1864 src_tag--; 1865 dst_point++; 1866 dst_tag++; 1867 } 1868 } 1869 1870 left->num_points = (FT_UInt)left->start; 1871 right->num_points += (FT_UInt)new_points; 1872 1873 right->movable = FALSE; 1874 left->movable = FALSE; 1875 } 1876 1877 Exit: 1878 return error; 1879 } 1880 1881 1882 /* documentation is in ftstroke.h */ 1883 1884 /* there's a lot of magic in this function! */ 1885 FT_EXPORT_DEF( FT_Error ) FT_Stroker_EndSubPath(FT_Stroker stroker)1886 FT_Stroker_EndSubPath( FT_Stroker stroker ) 1887 { 1888 FT_Error error = FT_Err_Ok; 1889 1890 1891 if ( !stroker ) 1892 { 1893 error = FT_THROW( Invalid_Argument ); 1894 goto Exit; 1895 } 1896 1897 if ( stroker->subpath_open ) 1898 { 1899 FT_StrokeBorder right = stroker->borders; 1900 1901 1902 /* All right, this is an opened path, we need to add a cap between */ 1903 /* right & left, add the reverse of left, then add a final cap */ 1904 /* between left & right. */ 1905 error = ft_stroker_cap( stroker, stroker->angle_in, 0 ); 1906 if ( error ) 1907 goto Exit; 1908 1909 /* add reversed points from `left' to `right' */ 1910 error = ft_stroker_add_reverse_left( stroker, TRUE ); 1911 if ( error ) 1912 goto Exit; 1913 1914 /* now add the final cap */ 1915 stroker->center = stroker->subpath_start; 1916 error = ft_stroker_cap( stroker, 1917 stroker->subpath_angle + FT_ANGLE_PI, 0 ); 1918 if ( error ) 1919 goto Exit; 1920 1921 /* Now end the right subpath accordingly. The left one is */ 1922 /* rewind and doesn't need further processing. */ 1923 ft_stroke_border_close( right, FALSE ); 1924 } 1925 else 1926 { 1927 FT_Angle turn; 1928 FT_Int inside_side; 1929 1930 1931 /* close the path if needed */ 1932 if ( stroker->center.x != stroker->subpath_start.x || 1933 stroker->center.y != stroker->subpath_start.y ) 1934 { 1935 error = FT_Stroker_LineTo( stroker, &stroker->subpath_start ); 1936 if ( error ) 1937 goto Exit; 1938 } 1939 1940 /* process the corner */ 1941 stroker->angle_out = stroker->subpath_angle; 1942 turn = FT_Angle_Diff( stroker->angle_in, 1943 stroker->angle_out ); 1944 1945 /* no specific corner processing is required if the turn is 0 */ 1946 if ( turn != 0 ) 1947 { 1948 /* when we turn to the right, the inside side is 0 */ 1949 /* otherwise, the inside side is 1 */ 1950 inside_side = ( turn < 0 ); 1951 1952 error = ft_stroker_inside( stroker, 1953 inside_side, 1954 stroker->subpath_line_length ); 1955 if ( error ) 1956 goto Exit; 1957 1958 /* process the outside side */ 1959 error = ft_stroker_outside( stroker, 1960 !inside_side, 1961 stroker->subpath_line_length ); 1962 if ( error ) 1963 goto Exit; 1964 } 1965 1966 /* then end our two subpaths */ 1967 ft_stroke_border_close( stroker->borders + 0, FALSE ); 1968 ft_stroke_border_close( stroker->borders + 1, TRUE ); 1969 } 1970 1971 Exit: 1972 return error; 1973 } 1974 1975 1976 /* documentation is in ftstroke.h */ 1977 1978 FT_EXPORT_DEF( FT_Error ) FT_Stroker_GetBorderCounts(FT_Stroker stroker,FT_StrokerBorder border,FT_UInt * anum_points,FT_UInt * anum_contours)1979 FT_Stroker_GetBorderCounts( FT_Stroker stroker, 1980 FT_StrokerBorder border, 1981 FT_UInt *anum_points, 1982 FT_UInt *anum_contours ) 1983 { 1984 FT_UInt num_points = 0, num_contours = 0; 1985 FT_Error error; 1986 1987 1988 if ( !stroker || border > 1 ) 1989 { 1990 error = FT_THROW( Invalid_Argument ); 1991 goto Exit; 1992 } 1993 1994 error = ft_stroke_border_get_counts( stroker->borders + border, 1995 &num_points, &num_contours ); 1996 Exit: 1997 if ( anum_points ) 1998 *anum_points = num_points; 1999 2000 if ( anum_contours ) 2001 *anum_contours = num_contours; 2002 2003 return error; 2004 } 2005 2006 2007 /* documentation is in ftstroke.h */ 2008 2009 FT_EXPORT_DEF( FT_Error ) FT_Stroker_GetCounts(FT_Stroker stroker,FT_UInt * anum_points,FT_UInt * anum_contours)2010 FT_Stroker_GetCounts( FT_Stroker stroker, 2011 FT_UInt *anum_points, 2012 FT_UInt *anum_contours ) 2013 { 2014 FT_UInt count1, count2, num_points = 0; 2015 FT_UInt count3, count4, num_contours = 0; 2016 FT_Error error; 2017 2018 2019 if ( !stroker ) 2020 { 2021 error = FT_THROW( Invalid_Argument ); 2022 goto Exit; 2023 } 2024 2025 error = ft_stroke_border_get_counts( stroker->borders + 0, 2026 &count1, &count2 ); 2027 if ( error ) 2028 goto Exit; 2029 2030 error = ft_stroke_border_get_counts( stroker->borders + 1, 2031 &count3, &count4 ); 2032 if ( error ) 2033 goto Exit; 2034 2035 num_points = count1 + count3; 2036 num_contours = count2 + count4; 2037 2038 Exit: 2039 if ( anum_points ) 2040 *anum_points = num_points; 2041 2042 if ( anum_contours ) 2043 *anum_contours = num_contours; 2044 2045 return error; 2046 } 2047 2048 2049 /* documentation is in ftstroke.h */ 2050 2051 FT_EXPORT_DEF( void ) FT_Stroker_ExportBorder(FT_Stroker stroker,FT_StrokerBorder border,FT_Outline * outline)2052 FT_Stroker_ExportBorder( FT_Stroker stroker, 2053 FT_StrokerBorder border, 2054 FT_Outline* outline ) 2055 { 2056 if ( !stroker || !outline ) 2057 return; 2058 2059 if ( border == FT_STROKER_BORDER_LEFT || 2060 border == FT_STROKER_BORDER_RIGHT ) 2061 { 2062 FT_StrokeBorder sborder = & stroker->borders[border]; 2063 2064 2065 if ( sborder->valid ) 2066 ft_stroke_border_export( sborder, outline ); 2067 } 2068 } 2069 2070 2071 /* documentation is in ftstroke.h */ 2072 2073 FT_EXPORT_DEF( void ) FT_Stroker_Export(FT_Stroker stroker,FT_Outline * outline)2074 FT_Stroker_Export( FT_Stroker stroker, 2075 FT_Outline* outline ) 2076 { 2077 FT_Stroker_ExportBorder( stroker, FT_STROKER_BORDER_LEFT, outline ); 2078 FT_Stroker_ExportBorder( stroker, FT_STROKER_BORDER_RIGHT, outline ); 2079 } 2080 2081 2082 /* documentation is in ftstroke.h */ 2083 2084 /* 2085 * The following is very similar to FT_Outline_Decompose, except 2086 * that we do support opened paths, and do not scale the outline. 2087 */ 2088 FT_EXPORT_DEF( FT_Error ) FT_Stroker_ParseOutline(FT_Stroker stroker,FT_Outline * outline,FT_Bool opened)2089 FT_Stroker_ParseOutline( FT_Stroker stroker, 2090 FT_Outline* outline, 2091 FT_Bool opened ) 2092 { 2093 FT_Vector v_last; 2094 FT_Vector v_control; 2095 FT_Vector v_start; 2096 2097 FT_Vector* point; 2098 FT_Vector* limit; 2099 char* tags; 2100 2101 FT_Error error; 2102 2103 FT_Int n; /* index of contour in outline */ 2104 FT_UInt first; /* index of first point in contour */ 2105 FT_Int tag; /* current point's state */ 2106 2107 2108 if ( !outline ) 2109 return FT_THROW( Invalid_Outline ); 2110 2111 if ( !stroker ) 2112 return FT_THROW( Invalid_Argument ); 2113 2114 FT_Stroker_Rewind( stroker ); 2115 2116 first = 0; 2117 2118 for ( n = 0; n < outline->n_contours; n++ ) 2119 { 2120 FT_UInt last; /* index of last point in contour */ 2121 2122 2123 last = (FT_UInt)outline->contours[n]; 2124 limit = outline->points + last; 2125 2126 /* skip empty points; we don't stroke these */ 2127 if ( last <= first ) 2128 { 2129 first = last + 1; 2130 continue; 2131 } 2132 2133 v_start = outline->points[first]; 2134 v_last = outline->points[last]; 2135 2136 v_control = v_start; 2137 2138 point = outline->points + first; 2139 tags = outline->tags + first; 2140 tag = FT_CURVE_TAG( tags[0] ); 2141 2142 /* A contour cannot start with a cubic control point! */ 2143 if ( tag == FT_CURVE_TAG_CUBIC ) 2144 goto Invalid_Outline; 2145 2146 /* check first point to determine origin */ 2147 if ( tag == FT_CURVE_TAG_CONIC ) 2148 { 2149 /* First point is conic control. Yes, this happens. */ 2150 if ( FT_CURVE_TAG( outline->tags[last] ) == FT_CURVE_TAG_ON ) 2151 { 2152 /* start at last point if it is on the curve */ 2153 v_start = v_last; 2154 limit--; 2155 } 2156 else 2157 { 2158 /* if both first and last points are conic, */ 2159 /* start at their middle */ 2160 v_start.x = ( v_start.x + v_last.x ) / 2; 2161 v_start.y = ( v_start.y + v_last.y ) / 2; 2162 } 2163 point--; 2164 tags--; 2165 } 2166 2167 error = FT_Stroker_BeginSubPath( stroker, &v_start, opened ); 2168 if ( error ) 2169 goto Exit; 2170 2171 while ( point < limit ) 2172 { 2173 point++; 2174 tags++; 2175 2176 tag = FT_CURVE_TAG( tags[0] ); 2177 switch ( tag ) 2178 { 2179 case FT_CURVE_TAG_ON: /* emit a single line_to */ 2180 { 2181 FT_Vector vec; 2182 2183 2184 vec.x = point->x; 2185 vec.y = point->y; 2186 2187 error = FT_Stroker_LineTo( stroker, &vec ); 2188 if ( error ) 2189 goto Exit; 2190 continue; 2191 } 2192 2193 case FT_CURVE_TAG_CONIC: /* consume conic arcs */ 2194 v_control.x = point->x; 2195 v_control.y = point->y; 2196 2197 Do_Conic: 2198 if ( point < limit ) 2199 { 2200 FT_Vector vec; 2201 FT_Vector v_middle; 2202 2203 2204 point++; 2205 tags++; 2206 tag = FT_CURVE_TAG( tags[0] ); 2207 2208 vec = point[0]; 2209 2210 if ( tag == FT_CURVE_TAG_ON ) 2211 { 2212 error = FT_Stroker_ConicTo( stroker, &v_control, &vec ); 2213 if ( error ) 2214 goto Exit; 2215 continue; 2216 } 2217 2218 if ( tag != FT_CURVE_TAG_CONIC ) 2219 goto Invalid_Outline; 2220 2221 v_middle.x = ( v_control.x + vec.x ) / 2; 2222 v_middle.y = ( v_control.y + vec.y ) / 2; 2223 2224 error = FT_Stroker_ConicTo( stroker, &v_control, &v_middle ); 2225 if ( error ) 2226 goto Exit; 2227 2228 v_control = vec; 2229 goto Do_Conic; 2230 } 2231 2232 error = FT_Stroker_ConicTo( stroker, &v_control, &v_start ); 2233 goto Close; 2234 2235 default: /* FT_CURVE_TAG_CUBIC */ 2236 { 2237 FT_Vector vec1, vec2; 2238 2239 2240 if ( point + 1 > limit || 2241 FT_CURVE_TAG( tags[1] ) != FT_CURVE_TAG_CUBIC ) 2242 goto Invalid_Outline; 2243 2244 point += 2; 2245 tags += 2; 2246 2247 vec1 = point[-2]; 2248 vec2 = point[-1]; 2249 2250 if ( point <= limit ) 2251 { 2252 FT_Vector vec; 2253 2254 2255 vec = point[0]; 2256 2257 error = FT_Stroker_CubicTo( stroker, &vec1, &vec2, &vec ); 2258 if ( error ) 2259 goto Exit; 2260 continue; 2261 } 2262 2263 error = FT_Stroker_CubicTo( stroker, &vec1, &vec2, &v_start ); 2264 goto Close; 2265 } 2266 } 2267 } 2268 2269 Close: 2270 if ( error ) 2271 goto Exit; 2272 2273 /* don't try to end the path if no segments have been generated */ 2274 if ( !stroker->first_point ) 2275 { 2276 error = FT_Stroker_EndSubPath( stroker ); 2277 if ( error ) 2278 goto Exit; 2279 } 2280 2281 first = last + 1; 2282 } 2283 2284 return FT_Err_Ok; 2285 2286 Exit: 2287 return error; 2288 2289 Invalid_Outline: 2290 return FT_THROW( Invalid_Outline ); 2291 } 2292 2293 2294 /* documentation is in ftstroke.h */ 2295 2296 FT_EXPORT_DEF( FT_Error ) FT_Glyph_Stroke(FT_Glyph * pglyph,FT_Stroker stroker,FT_Bool destroy)2297 FT_Glyph_Stroke( FT_Glyph *pglyph, 2298 FT_Stroker stroker, 2299 FT_Bool destroy ) 2300 { 2301 FT_Error error = FT_ERR( Invalid_Argument ); 2302 FT_Glyph glyph = NULL; 2303 2304 2305 if ( !pglyph ) 2306 goto Exit; 2307 2308 glyph = *pglyph; 2309 if ( !glyph || glyph->clazz != &ft_outline_glyph_class ) 2310 goto Exit; 2311 2312 { 2313 FT_Glyph copy; 2314 2315 2316 error = FT_Glyph_Copy( glyph, © ); 2317 if ( error ) 2318 goto Exit; 2319 2320 glyph = copy; 2321 } 2322 2323 { 2324 FT_OutlineGlyph oglyph = (FT_OutlineGlyph)glyph; 2325 FT_Outline* outline = &oglyph->outline; 2326 FT_UInt num_points, num_contours; 2327 2328 2329 error = FT_Stroker_ParseOutline( stroker, outline, FALSE ); 2330 if ( error ) 2331 goto Fail; 2332 2333 FT_Stroker_GetCounts( stroker, &num_points, &num_contours ); 2334 2335 FT_Outline_Done( glyph->library, outline ); 2336 2337 error = FT_Outline_New( glyph->library, 2338 num_points, 2339 (FT_Int)num_contours, 2340 outline ); 2341 if ( error ) 2342 goto Fail; 2343 2344 outline->n_points = 0; 2345 outline->n_contours = 0; 2346 2347 FT_Stroker_Export( stroker, outline ); 2348 } 2349 2350 if ( destroy ) 2351 FT_Done_Glyph( *pglyph ); 2352 2353 *pglyph = glyph; 2354 goto Exit; 2355 2356 Fail: 2357 FT_Done_Glyph( glyph ); 2358 glyph = NULL; 2359 2360 if ( !destroy ) 2361 *pglyph = NULL; 2362 2363 Exit: 2364 return error; 2365 } 2366 2367 2368 /* documentation is in ftstroke.h */ 2369 2370 FT_EXPORT_DEF( FT_Error ) FT_Glyph_StrokeBorder(FT_Glyph * pglyph,FT_Stroker stroker,FT_Bool inside,FT_Bool destroy)2371 FT_Glyph_StrokeBorder( FT_Glyph *pglyph, 2372 FT_Stroker stroker, 2373 FT_Bool inside, 2374 FT_Bool destroy ) 2375 { 2376 FT_Error error = FT_ERR( Invalid_Argument ); 2377 FT_Glyph glyph = NULL; 2378 2379 2380 if ( !pglyph ) 2381 goto Exit; 2382 2383 glyph = *pglyph; 2384 if ( !glyph || glyph->clazz != &ft_outline_glyph_class ) 2385 goto Exit; 2386 2387 { 2388 FT_Glyph copy; 2389 2390 2391 error = FT_Glyph_Copy( glyph, © ); 2392 if ( error ) 2393 goto Exit; 2394 2395 glyph = copy; 2396 } 2397 2398 { 2399 FT_OutlineGlyph oglyph = (FT_OutlineGlyph)glyph; 2400 FT_StrokerBorder border; 2401 FT_Outline* outline = &oglyph->outline; 2402 FT_UInt num_points, num_contours; 2403 2404 2405 border = FT_Outline_GetOutsideBorder( outline ); 2406 if ( inside ) 2407 { 2408 if ( border == FT_STROKER_BORDER_LEFT ) 2409 border = FT_STROKER_BORDER_RIGHT; 2410 else 2411 border = FT_STROKER_BORDER_LEFT; 2412 } 2413 2414 error = FT_Stroker_ParseOutline( stroker, outline, FALSE ); 2415 if ( error ) 2416 goto Fail; 2417 2418 FT_Stroker_GetBorderCounts( stroker, border, 2419 &num_points, &num_contours ); 2420 2421 FT_Outline_Done( glyph->library, outline ); 2422 2423 error = FT_Outline_New( glyph->library, 2424 num_points, 2425 (FT_Int)num_contours, 2426 outline ); 2427 if ( error ) 2428 goto Fail; 2429 2430 outline->n_points = 0; 2431 outline->n_contours = 0; 2432 2433 FT_Stroker_ExportBorder( stroker, border, outline ); 2434 } 2435 2436 if ( destroy ) 2437 FT_Done_Glyph( *pglyph ); 2438 2439 *pglyph = glyph; 2440 goto Exit; 2441 2442 Fail: 2443 FT_Done_Glyph( glyph ); 2444 glyph = NULL; 2445 2446 if ( !destroy ) 2447 *pglyph = NULL; 2448 2449 Exit: 2450 return error; 2451 } 2452 2453 2454 /* END */ 2455