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 #include "basepic.h" 28 29 30 /* declare an extern to access `ft_outline_glyph_class' globally */ 31 /* allocated in `ftglyph.c', and use the FT_OUTLINE_GLYPH_CLASS_GET */ 32 /* macro to access it when FT_CONFIG_OPTION_PIC is defined */ 33 #ifndef FT_CONFIG_OPTION_PIC 34 FT_CALLBACK_TABLE const FT_Glyph_Class ft_outline_glyph_class; 35 #endif 36 37 38 /* documentation is in ftstroke.h */ 39 40 FT_EXPORT_DEF( FT_StrokerBorder ) FT_Outline_GetInsideBorder(FT_Outline * outline)41 FT_Outline_GetInsideBorder( FT_Outline* outline ) 42 { 43 FT_Orientation o = FT_Outline_Get_Orientation( outline ); 44 45 46 return o == FT_ORIENTATION_TRUETYPE ? FT_STROKER_BORDER_RIGHT 47 : FT_STROKER_BORDER_LEFT; 48 } 49 50 51 /* documentation is in ftstroke.h */ 52 53 FT_EXPORT_DEF( FT_StrokerBorder ) FT_Outline_GetOutsideBorder(FT_Outline * outline)54 FT_Outline_GetOutsideBorder( FT_Outline* outline ) 55 { 56 FT_Orientation o = FT_Outline_Get_Orientation( outline ); 57 58 59 return o == FT_ORIENTATION_TRUETYPE ? FT_STROKER_BORDER_LEFT 60 : FT_STROKER_BORDER_RIGHT; 61 } 62 63 64 /*************************************************************************/ 65 /*************************************************************************/ 66 /***** *****/ 67 /***** BEZIER COMPUTATIONS *****/ 68 /***** *****/ 69 /*************************************************************************/ 70 /*************************************************************************/ 71 72 #define FT_SMALL_CONIC_THRESHOLD ( FT_ANGLE_PI / 6 ) 73 #define FT_SMALL_CUBIC_THRESHOLD ( FT_ANGLE_PI / 8 ) 74 75 #define FT_EPSILON 2 76 77 #define FT_IS_SMALL( x ) ( (x) > -FT_EPSILON && (x) < FT_EPSILON ) 78 79 80 static FT_Pos ft_pos_abs(FT_Pos x)81 ft_pos_abs( FT_Pos x ) 82 { 83 return x >= 0 ? x : -x; 84 } 85 86 87 static void ft_conic_split(FT_Vector * base)88 ft_conic_split( FT_Vector* base ) 89 { 90 FT_Pos a, b; 91 92 93 base[4].x = base[2].x; 94 b = base[1].x; 95 a = base[3].x = ( base[2].x + b ) / 2; 96 b = base[1].x = ( base[0].x + b ) / 2; 97 base[2].x = ( a + b ) / 2; 98 99 base[4].y = base[2].y; 100 b = base[1].y; 101 a = base[3].y = ( base[2].y + b ) / 2; 102 b = base[1].y = ( base[0].y + b ) / 2; 103 base[2].y = ( a + b ) / 2; 104 } 105 106 107 static FT_Bool ft_conic_is_small_enough(FT_Vector * base,FT_Angle * angle_in,FT_Angle * angle_out)108 ft_conic_is_small_enough( FT_Vector* base, 109 FT_Angle *angle_in, 110 FT_Angle *angle_out ) 111 { 112 FT_Vector d1, d2; 113 FT_Angle theta; 114 FT_Int close1, close2; 115 116 117 d1.x = base[1].x - base[2].x; 118 d1.y = base[1].y - base[2].y; 119 d2.x = base[0].x - base[1].x; 120 d2.y = base[0].y - base[1].y; 121 122 close1 = FT_IS_SMALL( d1.x ) && FT_IS_SMALL( d1.y ); 123 close2 = FT_IS_SMALL( d2.x ) && FT_IS_SMALL( d2.y ); 124 125 if ( close1 ) 126 { 127 if ( close2 ) 128 { 129 /* basically a point; */ 130 /* do nothing to retain original direction */ 131 } 132 else 133 { 134 *angle_in = 135 *angle_out = FT_Atan2( d2.x, d2.y ); 136 } 137 } 138 else /* !close1 */ 139 { 140 if ( close2 ) 141 { 142 *angle_in = 143 *angle_out = FT_Atan2( d1.x, d1.y ); 144 } 145 else 146 { 147 *angle_in = FT_Atan2( d1.x, d1.y ); 148 *angle_out = FT_Atan2( d2.x, d2.y ); 149 } 150 } 151 152 theta = ft_pos_abs( FT_Angle_Diff( *angle_in, *angle_out ) ); 153 154 return FT_BOOL( theta < FT_SMALL_CONIC_THRESHOLD ); 155 } 156 157 158 static void ft_cubic_split(FT_Vector * base)159 ft_cubic_split( FT_Vector* base ) 160 { 161 FT_Pos a, b, c, d; 162 163 164 base[6].x = base[3].x; 165 c = base[1].x; 166 d = base[2].x; 167 base[1].x = a = ( base[0].x + c ) / 2; 168 base[5].x = b = ( base[3].x + d ) / 2; 169 c = ( c + d ) / 2; 170 base[2].x = a = ( a + c ) / 2; 171 base[4].x = b = ( b + c ) / 2; 172 base[3].x = ( a + b ) / 2; 173 174 base[6].y = base[3].y; 175 c = base[1].y; 176 d = base[2].y; 177 base[1].y = a = ( base[0].y + c ) / 2; 178 base[5].y = b = ( base[3].y + d ) / 2; 179 c = ( c + d ) / 2; 180 base[2].y = a = ( a + c ) / 2; 181 base[4].y = b = ( b + c ) / 2; 182 base[3].y = ( a + b ) / 2; 183 } 184 185 186 /* Return the average of `angle1' and `angle2'. */ 187 /* This gives correct result even if `angle1' and `angle2' */ 188 /* have opposite signs. */ 189 static FT_Angle ft_angle_mean(FT_Angle angle1,FT_Angle angle2)190 ft_angle_mean( FT_Angle angle1, 191 FT_Angle angle2 ) 192 { 193 return angle1 + FT_Angle_Diff( angle1, angle2 ) / 2; 194 } 195 196 197 static FT_Bool ft_cubic_is_small_enough(FT_Vector * base,FT_Angle * angle_in,FT_Angle * angle_mid,FT_Angle * angle_out)198 ft_cubic_is_small_enough( FT_Vector* base, 199 FT_Angle *angle_in, 200 FT_Angle *angle_mid, 201 FT_Angle *angle_out ) 202 { 203 FT_Vector d1, d2, d3; 204 FT_Angle theta1, theta2; 205 FT_Int close1, close2, close3; 206 207 208 d1.x = base[2].x - base[3].x; 209 d1.y = base[2].y - base[3].y; 210 d2.x = base[1].x - base[2].x; 211 d2.y = base[1].y - base[2].y; 212 d3.x = base[0].x - base[1].x; 213 d3.y = base[0].y - base[1].y; 214 215 close1 = FT_IS_SMALL( d1.x ) && FT_IS_SMALL( d1.y ); 216 close2 = FT_IS_SMALL( d2.x ) && FT_IS_SMALL( d2.y ); 217 close3 = FT_IS_SMALL( d3.x ) && FT_IS_SMALL( d3.y ); 218 219 if ( close1 ) 220 { 221 if ( close2 ) 222 { 223 if ( close3 ) 224 { 225 /* basically a point; */ 226 /* do nothing to retain original direction */ 227 } 228 else /* !close3 */ 229 { 230 *angle_in = 231 *angle_mid = 232 *angle_out = FT_Atan2( d3.x, d3.y ); 233 } 234 } 235 else /* !close2 */ 236 { 237 if ( close3 ) 238 { 239 *angle_in = 240 *angle_mid = 241 *angle_out = FT_Atan2( d2.x, d2.y ); 242 } 243 else /* !close3 */ 244 { 245 *angle_in = 246 *angle_mid = FT_Atan2( d2.x, d2.y ); 247 *angle_out = FT_Atan2( d3.x, d3.y ); 248 } 249 } 250 } 251 else /* !close1 */ 252 { 253 if ( close2 ) 254 { 255 if ( close3 ) 256 { 257 *angle_in = 258 *angle_mid = 259 *angle_out = FT_Atan2( d1.x, d1.y ); 260 } 261 else /* !close3 */ 262 { 263 *angle_in = FT_Atan2( d1.x, d1.y ); 264 *angle_out = FT_Atan2( d3.x, d3.y ); 265 *angle_mid = ft_angle_mean( *angle_in, *angle_out ); 266 } 267 } 268 else /* !close2 */ 269 { 270 if ( close3 ) 271 { 272 *angle_in = FT_Atan2( d1.x, d1.y ); 273 *angle_mid = 274 *angle_out = FT_Atan2( d2.x, d2.y ); 275 } 276 else /* !close3 */ 277 { 278 *angle_in = FT_Atan2( d1.x, d1.y ); 279 *angle_mid = FT_Atan2( d2.x, d2.y ); 280 *angle_out = FT_Atan2( d3.x, d3.y ); 281 } 282 } 283 } 284 285 theta1 = ft_pos_abs( FT_Angle_Diff( *angle_in, *angle_mid ) ); 286 theta2 = ft_pos_abs( FT_Angle_Diff( *angle_mid, *angle_out ) ); 287 288 return FT_BOOL( theta1 < FT_SMALL_CUBIC_THRESHOLD && 289 theta2 < FT_SMALL_CUBIC_THRESHOLD ); 290 } 291 292 293 /*************************************************************************/ 294 /*************************************************************************/ 295 /***** *****/ 296 /***** STROKE BORDERS *****/ 297 /***** *****/ 298 /*************************************************************************/ 299 /*************************************************************************/ 300 301 typedef enum FT_StrokeTags_ 302 { 303 FT_STROKE_TAG_ON = 1, /* on-curve point */ 304 FT_STROKE_TAG_CUBIC = 2, /* cubic off-point */ 305 FT_STROKE_TAG_BEGIN = 4, /* sub-path start */ 306 FT_STROKE_TAG_END = 8 /* sub-path end */ 307 308 } FT_StrokeTags; 309 310 #define FT_STROKE_TAG_BEGIN_END ( FT_STROKE_TAG_BEGIN | FT_STROKE_TAG_END ) 311 312 typedef struct FT_StrokeBorderRec_ 313 { 314 FT_UInt num_points; 315 FT_UInt max_points; 316 FT_Vector* points; 317 FT_Byte* tags; 318 FT_Bool movable; /* TRUE for ends of lineto borders */ 319 FT_Int start; /* index of current sub-path start point */ 320 FT_Memory memory; 321 FT_Bool valid; 322 323 } FT_StrokeBorderRec, *FT_StrokeBorder; 324 325 326 static FT_Error ft_stroke_border_grow(FT_StrokeBorder border,FT_UInt new_points)327 ft_stroke_border_grow( FT_StrokeBorder border, 328 FT_UInt new_points ) 329 { 330 FT_UInt old_max = border->max_points; 331 FT_UInt new_max = border->num_points + new_points; 332 FT_Error error = FT_Err_Ok; 333 334 335 if ( new_max > old_max ) 336 { 337 FT_UInt cur_max = old_max; 338 FT_Memory memory = border->memory; 339 340 341 while ( cur_max < new_max ) 342 cur_max += ( cur_max >> 1 ) + 16; 343 344 if ( FT_RENEW_ARRAY( border->points, old_max, cur_max ) || 345 FT_RENEW_ARRAY( border->tags, old_max, cur_max ) ) 346 goto Exit; 347 348 border->max_points = cur_max; 349 } 350 351 Exit: 352 return error; 353 } 354 355 356 static void ft_stroke_border_close(FT_StrokeBorder border,FT_Bool reverse)357 ft_stroke_border_close( FT_StrokeBorder border, 358 FT_Bool reverse ) 359 { 360 FT_UInt start = (FT_UInt)border->start; 361 FT_UInt count = border->num_points; 362 363 364 FT_ASSERT( border->start >= 0 ); 365 366 /* don't record empty paths! */ 367 if ( count <= start + 1U ) 368 border->num_points = start; 369 else 370 { 371 /* copy the last point to the start of this sub-path, since */ 372 /* it contains the `adjusted' starting coordinates */ 373 border->num_points = --count; 374 border->points[start] = border->points[count]; 375 376 if ( reverse ) 377 { 378 /* reverse the points */ 379 { 380 FT_Vector* vec1 = border->points + start + 1; 381 FT_Vector* vec2 = border->points + count - 1; 382 383 384 for ( ; vec1 < vec2; vec1++, vec2-- ) 385 { 386 FT_Vector tmp; 387 388 389 tmp = *vec1; 390 *vec1 = *vec2; 391 *vec2 = tmp; 392 } 393 } 394 395 /* then the tags */ 396 { 397 FT_Byte* tag1 = border->tags + start + 1; 398 FT_Byte* tag2 = border->tags + count - 1; 399 400 401 for ( ; tag1 < tag2; tag1++, tag2-- ) 402 { 403 FT_Byte tmp; 404 405 406 tmp = *tag1; 407 *tag1 = *tag2; 408 *tag2 = tmp; 409 } 410 } 411 } 412 413 border->tags[start ] |= FT_STROKE_TAG_BEGIN; 414 border->tags[count - 1] |= FT_STROKE_TAG_END; 415 } 416 417 border->start = -1; 418 border->movable = FALSE; 419 } 420 421 422 static FT_Error ft_stroke_border_lineto(FT_StrokeBorder border,FT_Vector * to,FT_Bool movable)423 ft_stroke_border_lineto( FT_StrokeBorder border, 424 FT_Vector* to, 425 FT_Bool movable ) 426 { 427 FT_Error error = FT_Err_Ok; 428 429 430 FT_ASSERT( border->start >= 0 ); 431 432 if ( border->movable ) 433 { 434 /* move last point */ 435 border->points[border->num_points - 1] = *to; 436 } 437 else 438 { 439 /* don't add zero-length lineto */ 440 if ( border->num_points > 0 && 441 FT_IS_SMALL( border->points[border->num_points - 1].x - to->x ) && 442 FT_IS_SMALL( border->points[border->num_points - 1].y - to->y ) ) 443 return error; 444 445 /* add one point */ 446 error = ft_stroke_border_grow( border, 1 ); 447 if ( !error ) 448 { 449 FT_Vector* vec = border->points + border->num_points; 450 FT_Byte* tag = border->tags + border->num_points; 451 452 453 vec[0] = *to; 454 tag[0] = FT_STROKE_TAG_ON; 455 456 border->num_points += 1; 457 } 458 } 459 border->movable = movable; 460 return error; 461 } 462 463 464 static FT_Error ft_stroke_border_conicto(FT_StrokeBorder border,FT_Vector * control,FT_Vector * to)465 ft_stroke_border_conicto( FT_StrokeBorder border, 466 FT_Vector* control, 467 FT_Vector* to ) 468 { 469 FT_Error error; 470 471 472 FT_ASSERT( border->start >= 0 ); 473 474 error = ft_stroke_border_grow( border, 2 ); 475 if ( !error ) 476 { 477 FT_Vector* vec = border->points + border->num_points; 478 FT_Byte* tag = border->tags + border->num_points; 479 480 481 vec[0] = *control; 482 vec[1] = *to; 483 484 tag[0] = 0; 485 tag[1] = FT_STROKE_TAG_ON; 486 487 border->num_points += 2; 488 } 489 490 border->movable = FALSE; 491 492 return error; 493 } 494 495 496 static FT_Error ft_stroke_border_cubicto(FT_StrokeBorder border,FT_Vector * control1,FT_Vector * control2,FT_Vector * to)497 ft_stroke_border_cubicto( FT_StrokeBorder border, 498 FT_Vector* control1, 499 FT_Vector* control2, 500 FT_Vector* to ) 501 { 502 FT_Error error; 503 504 505 FT_ASSERT( border->start >= 0 ); 506 507 error = ft_stroke_border_grow( border, 3 ); 508 if ( !error ) 509 { 510 FT_Vector* vec = border->points + border->num_points; 511 FT_Byte* tag = border->tags + border->num_points; 512 513 514 vec[0] = *control1; 515 vec[1] = *control2; 516 vec[2] = *to; 517 518 tag[0] = FT_STROKE_TAG_CUBIC; 519 tag[1] = FT_STROKE_TAG_CUBIC; 520 tag[2] = FT_STROKE_TAG_ON; 521 522 border->num_points += 3; 523 } 524 525 border->movable = FALSE; 526 527 return error; 528 } 529 530 531 #define FT_ARC_CUBIC_ANGLE ( FT_ANGLE_PI / 2 ) 532 533 534 static FT_Error ft_stroke_border_arcto(FT_StrokeBorder border,FT_Vector * center,FT_Fixed radius,FT_Angle angle_start,FT_Angle angle_diff)535 ft_stroke_border_arcto( FT_StrokeBorder border, 536 FT_Vector* center, 537 FT_Fixed radius, 538 FT_Angle angle_start, 539 FT_Angle angle_diff ) 540 { 541 FT_Angle total, angle, step, rotate, next, theta; 542 FT_Vector a, b, a2, b2; 543 FT_Fixed length; 544 FT_Error error = FT_Err_Ok; 545 546 547 /* compute start point */ 548 FT_Vector_From_Polar( &a, radius, angle_start ); 549 a.x += center->x; 550 a.y += center->y; 551 552 total = angle_diff; 553 angle = angle_start; 554 rotate = ( angle_diff >= 0 ) ? FT_ANGLE_PI2 : -FT_ANGLE_PI2; 555 556 while ( total != 0 ) 557 { 558 step = total; 559 if ( step > FT_ARC_CUBIC_ANGLE ) 560 step = FT_ARC_CUBIC_ANGLE; 561 562 else if ( step < -FT_ARC_CUBIC_ANGLE ) 563 step = -FT_ARC_CUBIC_ANGLE; 564 565 next = angle + step; 566 theta = step; 567 if ( theta < 0 ) 568 theta = -theta; 569 570 theta >>= 1; 571 572 /* compute end point */ 573 FT_Vector_From_Polar( &b, radius, next ); 574 b.x += center->x; 575 b.y += center->y; 576 577 /* compute first and second control points */ 578 length = FT_MulDiv( radius, FT_Sin( theta ) * 4, 579 ( 0x10000L + FT_Cos( theta ) ) * 3 ); 580 581 FT_Vector_From_Polar( &a2, length, angle + rotate ); 582 a2.x += a.x; 583 a2.y += a.y; 584 585 FT_Vector_From_Polar( &b2, length, next - rotate ); 586 b2.x += b.x; 587 b2.y += b.y; 588 589 /* add cubic arc */ 590 error = ft_stroke_border_cubicto( border, &a2, &b2, &b ); 591 if ( error ) 592 break; 593 594 /* process the rest of the arc ?? */ 595 a = b; 596 total -= step; 597 angle = next; 598 } 599 600 return error; 601 } 602 603 604 static FT_Error ft_stroke_border_moveto(FT_StrokeBorder border,FT_Vector * to)605 ft_stroke_border_moveto( FT_StrokeBorder border, 606 FT_Vector* to ) 607 { 608 /* close current open path if any ? */ 609 if ( border->start >= 0 ) 610 ft_stroke_border_close( border, FALSE ); 611 612 border->start = (FT_Int)border->num_points; 613 border->movable = FALSE; 614 615 return ft_stroke_border_lineto( border, to, FALSE ); 616 } 617 618 619 static void ft_stroke_border_init(FT_StrokeBorder border,FT_Memory memory)620 ft_stroke_border_init( FT_StrokeBorder border, 621 FT_Memory memory ) 622 { 623 border->memory = memory; 624 border->points = NULL; 625 border->tags = NULL; 626 627 border->num_points = 0; 628 border->max_points = 0; 629 border->start = -1; 630 border->valid = FALSE; 631 } 632 633 634 static void ft_stroke_border_reset(FT_StrokeBorder border)635 ft_stroke_border_reset( FT_StrokeBorder border ) 636 { 637 border->num_points = 0; 638 border->start = -1; 639 border->valid = FALSE; 640 } 641 642 643 static void ft_stroke_border_done(FT_StrokeBorder border)644 ft_stroke_border_done( FT_StrokeBorder border ) 645 { 646 FT_Memory memory = border->memory; 647 648 649 FT_FREE( border->points ); 650 FT_FREE( border->tags ); 651 652 border->num_points = 0; 653 border->max_points = 0; 654 border->start = -1; 655 border->valid = FALSE; 656 } 657 658 659 static FT_Error ft_stroke_border_get_counts(FT_StrokeBorder border,FT_UInt * anum_points,FT_UInt * anum_contours)660 ft_stroke_border_get_counts( FT_StrokeBorder border, 661 FT_UInt *anum_points, 662 FT_UInt *anum_contours ) 663 { 664 FT_Error error = FT_Err_Ok; 665 FT_UInt num_points = 0; 666 FT_UInt num_contours = 0; 667 668 FT_UInt count = border->num_points; 669 FT_Vector* point = border->points; 670 FT_Byte* tags = border->tags; 671 FT_Int in_contour = 0; 672 673 674 for ( ; count > 0; count--, num_points++, point++, tags++ ) 675 { 676 if ( tags[0] & FT_STROKE_TAG_BEGIN ) 677 { 678 if ( in_contour != 0 ) 679 goto Fail; 680 681 in_contour = 1; 682 } 683 else if ( in_contour == 0 ) 684 goto Fail; 685 686 if ( tags[0] & FT_STROKE_TAG_END ) 687 { 688 in_contour = 0; 689 num_contours++; 690 } 691 } 692 693 if ( in_contour != 0 ) 694 goto Fail; 695 696 border->valid = TRUE; 697 698 Exit: 699 *anum_points = num_points; 700 *anum_contours = num_contours; 701 return error; 702 703 Fail: 704 num_points = 0; 705 num_contours = 0; 706 goto Exit; 707 } 708 709 710 static void ft_stroke_border_export(FT_StrokeBorder border,FT_Outline * outline)711 ft_stroke_border_export( FT_StrokeBorder border, 712 FT_Outline* outline ) 713 { 714 /* copy point locations */ 715 if ( border->num_points ) 716 FT_ARRAY_COPY( outline->points + outline->n_points, 717 border->points, 718 border->num_points ); 719 720 /* copy tags */ 721 { 722 FT_UInt count = border->num_points; 723 FT_Byte* read = border->tags; 724 FT_Byte* write = (FT_Byte*)outline->tags + outline->n_points; 725 726 727 for ( ; count > 0; count--, read++, write++ ) 728 { 729 if ( *read & FT_STROKE_TAG_ON ) 730 *write = FT_CURVE_TAG_ON; 731 else if ( *read & FT_STROKE_TAG_CUBIC ) 732 *write = FT_CURVE_TAG_CUBIC; 733 else 734 *write = FT_CURVE_TAG_CONIC; 735 } 736 } 737 738 /* copy contours */ 739 { 740 FT_UInt count = border->num_points; 741 FT_Byte* tags = border->tags; 742 FT_Short* write = outline->contours + outline->n_contours; 743 FT_Short idx = (FT_Short)outline->n_points; 744 745 746 for ( ; count > 0; count--, tags++, idx++ ) 747 { 748 if ( *tags & FT_STROKE_TAG_END ) 749 { 750 *write++ = idx; 751 outline->n_contours++; 752 } 753 } 754 } 755 756 outline->n_points += (short)border->num_points; 757 758 FT_ASSERT( FT_Outline_Check( outline ) == 0 ); 759 } 760 761 762 /*************************************************************************/ 763 /*************************************************************************/ 764 /***** *****/ 765 /***** STROKER *****/ 766 /***** *****/ 767 /*************************************************************************/ 768 /*************************************************************************/ 769 770 #define FT_SIDE_TO_ROTATE( s ) ( FT_ANGLE_PI2 - (s) * FT_ANGLE_PI ) 771 772 typedef struct FT_StrokerRec_ 773 { 774 FT_Angle angle_in; /* direction into curr join */ 775 FT_Angle angle_out; /* direction out of join */ 776 FT_Vector center; /* current position */ 777 FT_Fixed line_length; /* length of last lineto */ 778 FT_Bool first_point; /* is this the start? */ 779 FT_Bool subpath_open; /* is the subpath open? */ 780 FT_Angle subpath_angle; /* subpath start direction */ 781 FT_Vector subpath_start; /* subpath start position */ 782 FT_Fixed subpath_line_length; /* subpath start lineto len */ 783 FT_Bool handle_wide_strokes; /* use wide strokes logic? */ 784 785 FT_Stroker_LineCap line_cap; 786 FT_Stroker_LineJoin line_join; 787 FT_Stroker_LineJoin line_join_saved; 788 FT_Fixed miter_limit; 789 FT_Fixed radius; 790 791 FT_StrokeBorderRec borders[2]; 792 FT_Library library; 793 794 } FT_StrokerRec; 795 796 797 /* documentation is in ftstroke.h */ 798 799 FT_EXPORT_DEF( FT_Error ) FT_Stroker_New(FT_Library library,FT_Stroker * astroker)800 FT_Stroker_New( FT_Library library, 801 FT_Stroker *astroker ) 802 { 803 FT_Error error; /* assigned in FT_NEW */ 804 FT_Memory memory; 805 FT_Stroker stroker = NULL; 806 807 808 if ( !library ) 809 return FT_THROW( Invalid_Library_Handle ); 810 811 if ( !astroker ) 812 return FT_THROW( Invalid_Argument ); 813 814 memory = library->memory; 815 816 if ( !FT_NEW( stroker ) ) 817 { 818 stroker->library = library; 819 820 ft_stroke_border_init( &stroker->borders[0], memory ); 821 ft_stroke_border_init( &stroker->borders[1], memory ); 822 } 823 824 *astroker = stroker; 825 826 return error; 827 } 828 829 830 /* documentation is in ftstroke.h */ 831 832 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)833 FT_Stroker_Set( FT_Stroker stroker, 834 FT_Fixed radius, 835 FT_Stroker_LineCap line_cap, 836 FT_Stroker_LineJoin line_join, 837 FT_Fixed miter_limit ) 838 { 839 if ( !stroker ) 840 return; 841 842 stroker->radius = radius; 843 stroker->line_cap = line_cap; 844 stroker->line_join = line_join; 845 stroker->miter_limit = miter_limit; 846 847 /* ensure miter limit has sensible value */ 848 if ( stroker->miter_limit < 0x10000L ) 849 stroker->miter_limit = 0x10000L; 850 851 /* save line join style: */ 852 /* line join style can be temporarily changed when stroking curves */ 853 stroker->line_join_saved = line_join; 854 855 FT_Stroker_Rewind( stroker ); 856 } 857 858 859 /* documentation is in ftstroke.h */ 860 861 FT_EXPORT_DEF( void ) FT_Stroker_Rewind(FT_Stroker stroker)862 FT_Stroker_Rewind( FT_Stroker stroker ) 863 { 864 if ( stroker ) 865 { 866 ft_stroke_border_reset( &stroker->borders[0] ); 867 ft_stroke_border_reset( &stroker->borders[1] ); 868 } 869 } 870 871 872 /* documentation is in ftstroke.h */ 873 874 FT_EXPORT_DEF( void ) FT_Stroker_Done(FT_Stroker stroker)875 FT_Stroker_Done( FT_Stroker stroker ) 876 { 877 if ( stroker ) 878 { 879 FT_Memory memory = stroker->library->memory; 880 881 882 ft_stroke_border_done( &stroker->borders[0] ); 883 ft_stroke_border_done( &stroker->borders[1] ); 884 885 stroker->library = NULL; 886 FT_FREE( stroker ); 887 } 888 } 889 890 891 /* create a circular arc at a corner or cap */ 892 static FT_Error ft_stroker_arcto(FT_Stroker stroker,FT_Int side)893 ft_stroker_arcto( FT_Stroker stroker, 894 FT_Int side ) 895 { 896 FT_Angle total, rotate; 897 FT_Fixed radius = stroker->radius; 898 FT_Error error = FT_Err_Ok; 899 FT_StrokeBorder border = stroker->borders + side; 900 901 902 rotate = FT_SIDE_TO_ROTATE( side ); 903 904 total = FT_Angle_Diff( stroker->angle_in, stroker->angle_out ); 905 if ( total == FT_ANGLE_PI ) 906 total = -rotate * 2; 907 908 error = ft_stroke_border_arcto( border, 909 &stroker->center, 910 radius, 911 stroker->angle_in + rotate, 912 total ); 913 border->movable = FALSE; 914 return error; 915 } 916 917 918 /* add a cap at the end of an opened path */ 919 static FT_Error ft_stroker_cap(FT_Stroker stroker,FT_Angle angle,FT_Int side)920 ft_stroker_cap( FT_Stroker stroker, 921 FT_Angle angle, 922 FT_Int side ) 923 { 924 FT_Error error = FT_Err_Ok; 925 926 927 if ( stroker->line_cap == FT_STROKER_LINECAP_ROUND ) 928 { 929 /* add a round cap */ 930 stroker->angle_in = angle; 931 stroker->angle_out = angle + FT_ANGLE_PI; 932 933 error = ft_stroker_arcto( stroker, side ); 934 } 935 else if ( stroker->line_cap == FT_STROKER_LINECAP_SQUARE ) 936 { 937 /* add a square cap */ 938 FT_Vector delta, delta2; 939 FT_Angle rotate = FT_SIDE_TO_ROTATE( side ); 940 FT_Fixed radius = stroker->radius; 941 FT_StrokeBorder border = stroker->borders + side; 942 943 944 FT_Vector_From_Polar( &delta2, radius, angle + rotate ); 945 FT_Vector_From_Polar( &delta, radius, angle ); 946 947 delta.x += stroker->center.x + delta2.x; 948 delta.y += stroker->center.y + delta2.y; 949 950 error = ft_stroke_border_lineto( border, &delta, FALSE ); 951 if ( error ) 952 goto Exit; 953 954 FT_Vector_From_Polar( &delta2, radius, angle - rotate ); 955 FT_Vector_From_Polar( &delta, radius, angle ); 956 957 delta.x += delta2.x + stroker->center.x; 958 delta.y += delta2.y + stroker->center.y; 959 960 error = ft_stroke_border_lineto( border, &delta, FALSE ); 961 } 962 else if ( stroker->line_cap == FT_STROKER_LINECAP_BUTT ) 963 { 964 /* add a butt ending */ 965 FT_Vector delta; 966 FT_Angle rotate = FT_SIDE_TO_ROTATE( side ); 967 FT_Fixed radius = stroker->radius; 968 FT_StrokeBorder border = stroker->borders + side; 969 970 971 FT_Vector_From_Polar( &delta, radius, angle + rotate ); 972 973 delta.x += stroker->center.x; 974 delta.y += stroker->center.y; 975 976 error = ft_stroke_border_lineto( border, &delta, FALSE ); 977 if ( error ) 978 goto Exit; 979 980 FT_Vector_From_Polar( &delta, radius, angle - rotate ); 981 982 delta.x += stroker->center.x; 983 delta.y += stroker->center.y; 984 985 error = ft_stroke_border_lineto( border, &delta, FALSE ); 986 } 987 988 Exit: 989 return error; 990 } 991 992 993 /* process an inside corner, i.e. compute intersection */ 994 static FT_Error ft_stroker_inside(FT_Stroker stroker,FT_Int side,FT_Fixed line_length)995 ft_stroker_inside( FT_Stroker stroker, 996 FT_Int side, 997 FT_Fixed line_length ) 998 { 999 FT_StrokeBorder border = stroker->borders + side; 1000 FT_Angle phi, theta, rotate; 1001 FT_Fixed length, thcos; 1002 FT_Vector delta; 1003 FT_Error error = FT_Err_Ok; 1004 FT_Bool intersect; /* use intersection of lines? */ 1005 1006 1007 rotate = FT_SIDE_TO_ROTATE( side ); 1008 1009 theta = FT_Angle_Diff( stroker->angle_in, stroker->angle_out ) / 2; 1010 1011 /* Only intersect borders if between two lineto's and both */ 1012 /* lines are long enough (line_length is zero for curves). */ 1013 /* Also avoid U-turns of nearly 180 degree. */ 1014 if ( !border->movable || line_length == 0 || 1015 theta > 0x59C000 || theta < -0x59C000 ) 1016 intersect = FALSE; 1017 else 1018 { 1019 /* compute minimum required length of lines */ 1020 FT_Fixed min_length = ft_pos_abs( FT_MulFix( stroker->radius, 1021 FT_Tan( theta ) ) ); 1022 1023 1024 intersect = FT_BOOL( min_length && 1025 stroker->line_length >= min_length && 1026 line_length >= min_length ); 1027 } 1028 1029 if ( !intersect ) 1030 { 1031 FT_Vector_From_Polar( &delta, stroker->radius, 1032 stroker->angle_out + rotate ); 1033 delta.x += stroker->center.x; 1034 delta.y += stroker->center.y; 1035 1036 border->movable = FALSE; 1037 } 1038 else 1039 { 1040 /* compute median angle */ 1041 phi = stroker->angle_in + theta; 1042 1043 thcos = FT_Cos( theta ); 1044 1045 length = FT_DivFix( stroker->radius, thcos ); 1046 1047 FT_Vector_From_Polar( &delta, length, phi + rotate ); 1048 delta.x += stroker->center.x; 1049 delta.y += stroker->center.y; 1050 } 1051 1052 error = ft_stroke_border_lineto( border, &delta, FALSE ); 1053 1054 return error; 1055 } 1056 1057 1058 /* process an outside corner, i.e. compute bevel/miter/round */ 1059 static FT_Error ft_stroker_outside(FT_Stroker stroker,FT_Int side,FT_Fixed line_length)1060 ft_stroker_outside( FT_Stroker stroker, 1061 FT_Int side, 1062 FT_Fixed line_length ) 1063 { 1064 FT_StrokeBorder border = stroker->borders + side; 1065 FT_Error error; 1066 FT_Angle rotate; 1067 1068 1069 if ( stroker->line_join == FT_STROKER_LINEJOIN_ROUND ) 1070 error = ft_stroker_arcto( stroker, side ); 1071 else 1072 { 1073 /* this is a mitered (pointed) or beveled (truncated) corner */ 1074 FT_Fixed sigma = 0, radius = stroker->radius; 1075 FT_Angle theta = 0, phi = 0; 1076 FT_Fixed thcos = 0; 1077 FT_Bool bevel, fixed_bevel; 1078 1079 1080 rotate = FT_SIDE_TO_ROTATE( side ); 1081 1082 bevel = 1083 FT_BOOL( stroker->line_join == FT_STROKER_LINEJOIN_BEVEL ); 1084 1085 fixed_bevel = 1086 FT_BOOL( stroker->line_join != FT_STROKER_LINEJOIN_MITER_VARIABLE ); 1087 1088 if ( !bevel ) 1089 { 1090 theta = FT_Angle_Diff( stroker->angle_in, stroker->angle_out ); 1091 1092 if ( theta == FT_ANGLE_PI ) 1093 { 1094 theta = rotate; 1095 phi = stroker->angle_in; 1096 } 1097 else 1098 { 1099 theta /= 2; 1100 phi = stroker->angle_in + theta + rotate; 1101 } 1102 1103 thcos = FT_Cos( theta ); 1104 sigma = FT_MulFix( stroker->miter_limit, thcos ); 1105 1106 /* is miter limit exceeded? */ 1107 if ( sigma < 0x10000L ) 1108 { 1109 /* don't create variable bevels for very small deviations; */ 1110 /* FT_Sin(x) = 0 for x <= 57 */ 1111 if ( fixed_bevel || ft_pos_abs( theta ) > 57 ) 1112 bevel = TRUE; 1113 } 1114 } 1115 1116 if ( bevel ) /* this is a bevel (broken angle) */ 1117 { 1118 if ( fixed_bevel ) 1119 { 1120 /* the outer corners are simply joined together */ 1121 FT_Vector delta; 1122 1123 1124 /* add bevel */ 1125 FT_Vector_From_Polar( &delta, 1126 radius, 1127 stroker->angle_out + rotate ); 1128 delta.x += stroker->center.x; 1129 delta.y += stroker->center.y; 1130 1131 border->movable = FALSE; 1132 error = ft_stroke_border_lineto( border, &delta, FALSE ); 1133 } 1134 else /* variable bevel */ 1135 { 1136 /* the miter is truncated */ 1137 FT_Vector middle, delta; 1138 FT_Fixed length; 1139 1140 1141 /* compute middle point */ 1142 FT_Vector_From_Polar( &middle, 1143 FT_MulFix( radius, stroker->miter_limit ), 1144 phi ); 1145 middle.x += stroker->center.x; 1146 middle.y += stroker->center.y; 1147 1148 /* compute first angle point */ 1149 length = FT_MulDiv( radius, 0x10000L - sigma, 1150 ft_pos_abs( FT_Sin( theta ) ) ); 1151 1152 FT_Vector_From_Polar( &delta, length, phi + rotate ); 1153 delta.x += middle.x; 1154 delta.y += middle.y; 1155 1156 error = ft_stroke_border_lineto( border, &delta, FALSE ); 1157 if ( error ) 1158 goto Exit; 1159 1160 /* compute second angle point */ 1161 FT_Vector_From_Polar( &delta, length, phi - rotate ); 1162 delta.x += middle.x; 1163 delta.y += middle.y; 1164 1165 error = ft_stroke_border_lineto( border, &delta, FALSE ); 1166 if ( error ) 1167 goto Exit; 1168 1169 /* finally, add an end point; only needed if not lineto */ 1170 /* (line_length is zero for curves) */ 1171 if ( line_length == 0 ) 1172 { 1173 FT_Vector_From_Polar( &delta, 1174 radius, 1175 stroker->angle_out + rotate ); 1176 1177 delta.x += stroker->center.x; 1178 delta.y += stroker->center.y; 1179 1180 error = ft_stroke_border_lineto( border, &delta, FALSE ); 1181 } 1182 } 1183 } 1184 else /* this is a miter (intersection) */ 1185 { 1186 FT_Fixed length; 1187 FT_Vector delta; 1188 1189 1190 length = FT_DivFix( stroker->radius, thcos ); 1191 1192 FT_Vector_From_Polar( &delta, length, phi ); 1193 delta.x += stroker->center.x; 1194 delta.y += stroker->center.y; 1195 1196 error = ft_stroke_border_lineto( border, &delta, FALSE ); 1197 if ( error ) 1198 goto Exit; 1199 1200 /* now add an end point; only needed if not lineto */ 1201 /* (line_length is zero for curves) */ 1202 if ( line_length == 0 ) 1203 { 1204 FT_Vector_From_Polar( &delta, 1205 stroker->radius, 1206 stroker->angle_out + rotate ); 1207 delta.x += stroker->center.x; 1208 delta.y += stroker->center.y; 1209 1210 error = ft_stroke_border_lineto( border, &delta, FALSE ); 1211 } 1212 } 1213 } 1214 1215 Exit: 1216 return error; 1217 } 1218 1219 1220 static FT_Error ft_stroker_process_corner(FT_Stroker stroker,FT_Fixed line_length)1221 ft_stroker_process_corner( FT_Stroker stroker, 1222 FT_Fixed line_length ) 1223 { 1224 FT_Error error = FT_Err_Ok; 1225 FT_Angle turn; 1226 FT_Int inside_side; 1227 1228 1229 turn = FT_Angle_Diff( stroker->angle_in, stroker->angle_out ); 1230 1231 /* no specific corner processing is required if the turn is 0 */ 1232 if ( turn == 0 ) 1233 goto Exit; 1234 1235 /* when we turn to the right, the inside side is 0 */ 1236 /* otherwise, the inside side is 1 */ 1237 inside_side = ( turn < 0 ); 1238 1239 /* process the inside side */ 1240 error = ft_stroker_inside( stroker, inside_side, line_length ); 1241 if ( error ) 1242 goto Exit; 1243 1244 /* process the outside side */ 1245 error = ft_stroker_outside( stroker, !inside_side, line_length ); 1246 1247 Exit: 1248 return error; 1249 } 1250 1251 1252 /* add two points to the left and right borders corresponding to the */ 1253 /* start of the subpath */ 1254 static FT_Error ft_stroker_subpath_start(FT_Stroker stroker,FT_Angle start_angle,FT_Fixed line_length)1255 ft_stroker_subpath_start( FT_Stroker stroker, 1256 FT_Angle start_angle, 1257 FT_Fixed line_length ) 1258 { 1259 FT_Vector delta; 1260 FT_Vector point; 1261 FT_Error error; 1262 FT_StrokeBorder border; 1263 1264 1265 FT_Vector_From_Polar( &delta, stroker->radius, 1266 start_angle + FT_ANGLE_PI2 ); 1267 1268 point.x = stroker->center.x + delta.x; 1269 point.y = stroker->center.y + delta.y; 1270 1271 border = stroker->borders; 1272 error = ft_stroke_border_moveto( border, &point ); 1273 if ( error ) 1274 goto Exit; 1275 1276 point.x = stroker->center.x - delta.x; 1277 point.y = stroker->center.y - delta.y; 1278 1279 border++; 1280 error = ft_stroke_border_moveto( border, &point ); 1281 1282 /* save angle, position, and line length for last join */ 1283 /* (line_length is zero for curves) */ 1284 stroker->subpath_angle = start_angle; 1285 stroker->first_point = FALSE; 1286 stroker->subpath_line_length = line_length; 1287 1288 Exit: 1289 return error; 1290 } 1291 1292 1293 /* documentation is in ftstroke.h */ 1294 1295 FT_EXPORT_DEF( FT_Error ) FT_Stroker_LineTo(FT_Stroker stroker,FT_Vector * to)1296 FT_Stroker_LineTo( FT_Stroker stroker, 1297 FT_Vector* to ) 1298 { 1299 FT_Error error = FT_Err_Ok; 1300 FT_StrokeBorder border; 1301 FT_Vector delta; 1302 FT_Angle angle; 1303 FT_Int side; 1304 FT_Fixed line_length; 1305 1306 1307 if ( !stroker || !to ) 1308 return FT_THROW( Invalid_Argument ); 1309 1310 delta.x = to->x - stroker->center.x; 1311 delta.y = to->y - stroker->center.y; 1312 1313 /* a zero-length lineto is a no-op; avoid creating a spurious corner */ 1314 if ( delta.x == 0 && delta.y == 0 ) 1315 goto Exit; 1316 1317 /* compute length of line */ 1318 line_length = FT_Vector_Length( &delta ); 1319 1320 angle = FT_Atan2( delta.x, delta.y ); 1321 FT_Vector_From_Polar( &delta, stroker->radius, angle + FT_ANGLE_PI2 ); 1322 1323 /* process corner if necessary */ 1324 if ( stroker->first_point ) 1325 { 1326 /* This is the first segment of a subpath. We need to */ 1327 /* add a point to each border at their respective starting */ 1328 /* point locations. */ 1329 error = ft_stroker_subpath_start( stroker, angle, line_length ); 1330 if ( error ) 1331 goto Exit; 1332 } 1333 else 1334 { 1335 /* process the current corner */ 1336 stroker->angle_out = angle; 1337 error = ft_stroker_process_corner( stroker, line_length ); 1338 if ( error ) 1339 goto Exit; 1340 } 1341 1342 /* now add a line segment to both the `inside' and `outside' paths */ 1343 for ( border = stroker->borders, side = 1; side >= 0; side--, border++ ) 1344 { 1345 FT_Vector point; 1346 1347 1348 point.x = to->x + delta.x; 1349 point.y = to->y + delta.y; 1350 1351 /* the ends of lineto borders are movable */ 1352 error = ft_stroke_border_lineto( border, &point, TRUE ); 1353 if ( error ) 1354 goto Exit; 1355 1356 delta.x = -delta.x; 1357 delta.y = -delta.y; 1358 } 1359 1360 stroker->angle_in = angle; 1361 stroker->center = *to; 1362 stroker->line_length = line_length; 1363 1364 Exit: 1365 return error; 1366 } 1367 1368 1369 /* documentation is in ftstroke.h */ 1370 1371 FT_EXPORT_DEF( FT_Error ) FT_Stroker_ConicTo(FT_Stroker stroker,FT_Vector * control,FT_Vector * to)1372 FT_Stroker_ConicTo( FT_Stroker stroker, 1373 FT_Vector* control, 1374 FT_Vector* to ) 1375 { 1376 FT_Error error = FT_Err_Ok; 1377 FT_Vector bez_stack[34]; 1378 FT_Vector* arc; 1379 FT_Vector* limit = bez_stack + 30; 1380 FT_Bool first_arc = TRUE; 1381 1382 1383 if ( !stroker || !control || !to ) 1384 { 1385 error = FT_THROW( Invalid_Argument ); 1386 goto Exit; 1387 } 1388 1389 /* if all control points are coincident, this is a no-op; */ 1390 /* avoid creating a spurious corner */ 1391 if ( FT_IS_SMALL( stroker->center.x - control->x ) && 1392 FT_IS_SMALL( stroker->center.y - control->y ) && 1393 FT_IS_SMALL( control->x - to->x ) && 1394 FT_IS_SMALL( control->y - to->y ) ) 1395 { 1396 stroker->center = *to; 1397 goto Exit; 1398 } 1399 1400 arc = bez_stack; 1401 arc[0] = *to; 1402 arc[1] = *control; 1403 arc[2] = stroker->center; 1404 1405 while ( arc >= bez_stack ) 1406 { 1407 FT_Angle angle_in, angle_out; 1408 1409 1410 /* initialize with current direction */ 1411 angle_in = angle_out = stroker->angle_in; 1412 1413 if ( arc < limit && 1414 !ft_conic_is_small_enough( arc, &angle_in, &angle_out ) ) 1415 { 1416 if ( stroker->first_point ) 1417 stroker->angle_in = angle_in; 1418 1419 ft_conic_split( arc ); 1420 arc += 2; 1421 continue; 1422 } 1423 1424 if ( first_arc ) 1425 { 1426 first_arc = FALSE; 1427 1428 /* process corner if necessary */ 1429 if ( stroker->first_point ) 1430 error = ft_stroker_subpath_start( stroker, angle_in, 0 ); 1431 else 1432 { 1433 stroker->angle_out = angle_in; 1434 error = ft_stroker_process_corner( stroker, 0 ); 1435 } 1436 } 1437 else if ( ft_pos_abs( FT_Angle_Diff( stroker->angle_in, angle_in ) ) > 1438 FT_SMALL_CONIC_THRESHOLD / 4 ) 1439 { 1440 /* if the deviation from one arc to the next is too great, */ 1441 /* add a round corner */ 1442 stroker->center = arc[2]; 1443 stroker->angle_out = angle_in; 1444 stroker->line_join = FT_STROKER_LINEJOIN_ROUND; 1445 1446 error = ft_stroker_process_corner( stroker, 0 ); 1447 1448 /* reinstate line join style */ 1449 stroker->line_join = stroker->line_join_saved; 1450 } 1451 1452 if ( error ) 1453 goto Exit; 1454 1455 /* the arc's angle is small enough; we can add it directly to each */ 1456 /* border */ 1457 { 1458 FT_Vector ctrl, end; 1459 FT_Angle theta, phi, rotate, alpha0 = 0; 1460 FT_Fixed length; 1461 FT_StrokeBorder border; 1462 FT_Int side; 1463 1464 1465 theta = FT_Angle_Diff( angle_in, angle_out ) / 2; 1466 phi = angle_in + theta; 1467 length = FT_DivFix( stroker->radius, FT_Cos( theta ) ); 1468 1469 /* compute direction of original arc */ 1470 if ( stroker->handle_wide_strokes ) 1471 alpha0 = FT_Atan2( arc[0].x - arc[2].x, arc[0].y - arc[2].y ); 1472 1473 for ( border = stroker->borders, side = 0; 1474 side <= 1; 1475 side++, border++ ) 1476 { 1477 rotate = FT_SIDE_TO_ROTATE( side ); 1478 1479 /* compute control point */ 1480 FT_Vector_From_Polar( &ctrl, length, phi + rotate ); 1481 ctrl.x += arc[1].x; 1482 ctrl.y += arc[1].y; 1483 1484 /* compute end point */ 1485 FT_Vector_From_Polar( &end, stroker->radius, angle_out + rotate ); 1486 end.x += arc[0].x; 1487 end.y += arc[0].y; 1488 1489 if ( stroker->handle_wide_strokes ) 1490 { 1491 FT_Vector start; 1492 FT_Angle alpha1; 1493 1494 1495 /* determine whether the border radius is greater than the */ 1496 /* radius of curvature of the original arc */ 1497 start = border->points[border->num_points - 1]; 1498 1499 alpha1 = FT_Atan2( end.x - start.x, end.y - start.y ); 1500 1501 /* is the direction of the border arc opposite to */ 1502 /* that of the original arc? */ 1503 if ( ft_pos_abs( FT_Angle_Diff( alpha0, alpha1 ) ) > 1504 FT_ANGLE_PI / 2 ) 1505 { 1506 FT_Angle beta, gamma; 1507 FT_Vector bvec, delta; 1508 FT_Fixed blen, sinA, sinB, alen; 1509 1510 1511 /* use the sine rule to find the intersection point */ 1512 beta = FT_Atan2( arc[2].x - start.x, arc[2].y - start.y ); 1513 gamma = FT_Atan2( arc[0].x - end.x, arc[0].y - end.y ); 1514 1515 bvec.x = end.x - start.x; 1516 bvec.y = end.y - start.y; 1517 1518 blen = FT_Vector_Length( &bvec ); 1519 1520 sinA = ft_pos_abs( FT_Sin( alpha1 - gamma ) ); 1521 sinB = ft_pos_abs( FT_Sin( beta - gamma ) ); 1522 1523 alen = FT_MulDiv( blen, sinA, sinB ); 1524 1525 FT_Vector_From_Polar( &delta, alen, beta ); 1526 delta.x += start.x; 1527 delta.y += start.y; 1528 1529 /* circumnavigate the negative sector backwards */ 1530 border->movable = FALSE; 1531 error = ft_stroke_border_lineto( border, &delta, FALSE ); 1532 if ( error ) 1533 goto Exit; 1534 error = ft_stroke_border_lineto( border, &end, FALSE ); 1535 if ( error ) 1536 goto Exit; 1537 error = ft_stroke_border_conicto( border, &ctrl, &start ); 1538 if ( error ) 1539 goto Exit; 1540 /* and then move to the endpoint */ 1541 error = ft_stroke_border_lineto( border, &end, FALSE ); 1542 if ( error ) 1543 goto Exit; 1544 1545 continue; 1546 } 1547 1548 /* else fall through */ 1549 } 1550 1551 /* simply add an arc */ 1552 error = ft_stroke_border_conicto( border, &ctrl, &end ); 1553 if ( error ) 1554 goto Exit; 1555 } 1556 } 1557 1558 arc -= 2; 1559 1560 stroker->angle_in = angle_out; 1561 } 1562 1563 stroker->center = *to; 1564 1565 Exit: 1566 return error; 1567 } 1568 1569 1570 /* documentation is in ftstroke.h */ 1571 1572 FT_EXPORT_DEF( FT_Error ) FT_Stroker_CubicTo(FT_Stroker stroker,FT_Vector * control1,FT_Vector * control2,FT_Vector * to)1573 FT_Stroker_CubicTo( FT_Stroker stroker, 1574 FT_Vector* control1, 1575 FT_Vector* control2, 1576 FT_Vector* to ) 1577 { 1578 FT_Error error = FT_Err_Ok; 1579 FT_Vector bez_stack[37]; 1580 FT_Vector* arc; 1581 FT_Vector* limit = bez_stack + 32; 1582 FT_Bool first_arc = TRUE; 1583 1584 1585 if ( !stroker || !control1 || !control2 || !to ) 1586 { 1587 error = FT_THROW( Invalid_Argument ); 1588 goto Exit; 1589 } 1590 1591 /* if all control points are coincident, this is a no-op; */ 1592 /* avoid creating a spurious corner */ 1593 if ( FT_IS_SMALL( stroker->center.x - control1->x ) && 1594 FT_IS_SMALL( stroker->center.y - control1->y ) && 1595 FT_IS_SMALL( control1->x - control2->x ) && 1596 FT_IS_SMALL( control1->y - control2->y ) && 1597 FT_IS_SMALL( control2->x - to->x ) && 1598 FT_IS_SMALL( control2->y - to->y ) ) 1599 { 1600 stroker->center = *to; 1601 goto Exit; 1602 } 1603 1604 arc = bez_stack; 1605 arc[0] = *to; 1606 arc[1] = *control2; 1607 arc[2] = *control1; 1608 arc[3] = stroker->center; 1609 1610 while ( arc >= bez_stack ) 1611 { 1612 FT_Angle angle_in, angle_mid, angle_out; 1613 1614 1615 /* initialize with current direction */ 1616 angle_in = angle_out = angle_mid = stroker->angle_in; 1617 1618 if ( arc < limit && 1619 !ft_cubic_is_small_enough( arc, &angle_in, 1620 &angle_mid, &angle_out ) ) 1621 { 1622 if ( stroker->first_point ) 1623 stroker->angle_in = angle_in; 1624 1625 ft_cubic_split( arc ); 1626 arc += 3; 1627 continue; 1628 } 1629 1630 if ( first_arc ) 1631 { 1632 first_arc = FALSE; 1633 1634 /* process corner if necessary */ 1635 if ( stroker->first_point ) 1636 error = ft_stroker_subpath_start( stroker, angle_in, 0 ); 1637 else 1638 { 1639 stroker->angle_out = angle_in; 1640 error = ft_stroker_process_corner( stroker, 0 ); 1641 } 1642 } 1643 else if ( ft_pos_abs( FT_Angle_Diff( stroker->angle_in, angle_in ) ) > 1644 FT_SMALL_CUBIC_THRESHOLD / 4 ) 1645 { 1646 /* if the deviation from one arc to the next is too great, */ 1647 /* add a round corner */ 1648 stroker->center = arc[3]; 1649 stroker->angle_out = angle_in; 1650 stroker->line_join = FT_STROKER_LINEJOIN_ROUND; 1651 1652 error = ft_stroker_process_corner( stroker, 0 ); 1653 1654 /* reinstate line join style */ 1655 stroker->line_join = stroker->line_join_saved; 1656 } 1657 1658 if ( error ) 1659 goto Exit; 1660 1661 /* the arc's angle is small enough; we can add it directly to each */ 1662 /* border */ 1663 { 1664 FT_Vector ctrl1, ctrl2, end; 1665 FT_Angle theta1, phi1, theta2, phi2, rotate, alpha0 = 0; 1666 FT_Fixed length1, length2; 1667 FT_StrokeBorder border; 1668 FT_Int side; 1669 1670 1671 theta1 = FT_Angle_Diff( angle_in, angle_mid ) / 2; 1672 theta2 = FT_Angle_Diff( angle_mid, angle_out ) / 2; 1673 phi1 = ft_angle_mean( angle_in, angle_mid ); 1674 phi2 = ft_angle_mean( angle_mid, angle_out ); 1675 length1 = FT_DivFix( stroker->radius, FT_Cos( theta1 ) ); 1676 length2 = FT_DivFix( stroker->radius, FT_Cos( theta2 ) ); 1677 1678 /* compute direction of original arc */ 1679 if ( stroker->handle_wide_strokes ) 1680 alpha0 = FT_Atan2( arc[0].x - arc[3].x, arc[0].y - arc[3].y ); 1681 1682 for ( border = stroker->borders, side = 0; 1683 side <= 1; 1684 side++, border++ ) 1685 { 1686 rotate = FT_SIDE_TO_ROTATE( side ); 1687 1688 /* compute control points */ 1689 FT_Vector_From_Polar( &ctrl1, length1, phi1 + rotate ); 1690 ctrl1.x += arc[2].x; 1691 ctrl1.y += arc[2].y; 1692 1693 FT_Vector_From_Polar( &ctrl2, length2, phi2 + rotate ); 1694 ctrl2.x += arc[1].x; 1695 ctrl2.y += arc[1].y; 1696 1697 /* compute end point */ 1698 FT_Vector_From_Polar( &end, stroker->radius, angle_out + rotate ); 1699 end.x += arc[0].x; 1700 end.y += arc[0].y; 1701 1702 if ( stroker->handle_wide_strokes ) 1703 { 1704 FT_Vector start; 1705 FT_Angle alpha1; 1706 1707 1708 /* determine whether the border radius is greater than the */ 1709 /* radius of curvature of the original arc */ 1710 start = border->points[border->num_points - 1]; 1711 1712 alpha1 = FT_Atan2( end.x - start.x, end.y - start.y ); 1713 1714 /* is the direction of the border arc opposite to */ 1715 /* that of the original arc? */ 1716 if ( ft_pos_abs( FT_Angle_Diff( alpha0, alpha1 ) ) > 1717 FT_ANGLE_PI / 2 ) 1718 { 1719 FT_Angle beta, gamma; 1720 FT_Vector bvec, delta; 1721 FT_Fixed blen, sinA, sinB, alen; 1722 1723 1724 /* use the sine rule to find the intersection point */ 1725 beta = FT_Atan2( arc[3].x - start.x, arc[3].y - start.y ); 1726 gamma = FT_Atan2( arc[0].x - end.x, arc[0].y - end.y ); 1727 1728 bvec.x = end.x - start.x; 1729 bvec.y = end.y - start.y; 1730 1731 blen = FT_Vector_Length( &bvec ); 1732 1733 sinA = ft_pos_abs( FT_Sin( alpha1 - gamma ) ); 1734 sinB = ft_pos_abs( FT_Sin( beta - gamma ) ); 1735 1736 alen = FT_MulDiv( blen, sinA, sinB ); 1737 1738 FT_Vector_From_Polar( &delta, alen, beta ); 1739 delta.x += start.x; 1740 delta.y += start.y; 1741 1742 /* circumnavigate the negative sector backwards */ 1743 border->movable = FALSE; 1744 error = ft_stroke_border_lineto( border, &delta, FALSE ); 1745 if ( error ) 1746 goto Exit; 1747 error = ft_stroke_border_lineto( border, &end, FALSE ); 1748 if ( error ) 1749 goto Exit; 1750 error = ft_stroke_border_cubicto( border, 1751 &ctrl2, 1752 &ctrl1, 1753 &start ); 1754 if ( error ) 1755 goto Exit; 1756 /* and then move to the endpoint */ 1757 error = ft_stroke_border_lineto( border, &end, FALSE ); 1758 if ( error ) 1759 goto Exit; 1760 1761 continue; 1762 } 1763 1764 /* else fall through */ 1765 } 1766 1767 /* simply add an arc */ 1768 error = ft_stroke_border_cubicto( border, &ctrl1, &ctrl2, &end ); 1769 if ( error ) 1770 goto Exit; 1771 } 1772 } 1773 1774 arc -= 3; 1775 1776 stroker->angle_in = angle_out; 1777 } 1778 1779 stroker->center = *to; 1780 1781 Exit: 1782 return error; 1783 } 1784 1785 1786 /* documentation is in ftstroke.h */ 1787 1788 FT_EXPORT_DEF( FT_Error ) FT_Stroker_BeginSubPath(FT_Stroker stroker,FT_Vector * to,FT_Bool open)1789 FT_Stroker_BeginSubPath( FT_Stroker stroker, 1790 FT_Vector* to, 1791 FT_Bool open ) 1792 { 1793 if ( !stroker || !to ) 1794 return FT_THROW( Invalid_Argument ); 1795 1796 /* We cannot process the first point, because there is not enough */ 1797 /* information regarding its corner/cap. The latter will be processed */ 1798 /* in the `FT_Stroker_EndSubPath' routine. */ 1799 /* */ 1800 stroker->first_point = TRUE; 1801 stroker->center = *to; 1802 stroker->subpath_open = open; 1803 1804 /* Determine if we need to check whether the border radius is greater */ 1805 /* than the radius of curvature of a curve, to handle this case */ 1806 /* specially. This is only required if bevel joins or butt caps may */ 1807 /* be created, because round & miter joins and round & square caps */ 1808 /* cover the negative sector created with wide strokes. */ 1809 stroker->handle_wide_strokes = 1810 FT_BOOL( stroker->line_join != FT_STROKER_LINEJOIN_ROUND || 1811 ( stroker->subpath_open && 1812 stroker->line_cap == FT_STROKER_LINECAP_BUTT ) ); 1813 1814 /* record the subpath start point for each border */ 1815 stroker->subpath_start = *to; 1816 1817 stroker->angle_in = 0; 1818 1819 return FT_Err_Ok; 1820 } 1821 1822 1823 static FT_Error ft_stroker_add_reverse_left(FT_Stroker stroker,FT_Bool open)1824 ft_stroker_add_reverse_left( FT_Stroker stroker, 1825 FT_Bool open ) 1826 { 1827 FT_StrokeBorder right = stroker->borders + 0; 1828 FT_StrokeBorder left = stroker->borders + 1; 1829 FT_Int new_points; 1830 FT_Error error = FT_Err_Ok; 1831 1832 1833 FT_ASSERT( left->start >= 0 ); 1834 1835 new_points = (FT_Int)left->num_points - left->start; 1836 if ( new_points > 0 ) 1837 { 1838 error = ft_stroke_border_grow( right, (FT_UInt)new_points ); 1839 if ( error ) 1840 goto Exit; 1841 1842 { 1843 FT_Vector* dst_point = right->points + right->num_points; 1844 FT_Byte* dst_tag = right->tags + right->num_points; 1845 FT_Vector* src_point = left->points + left->num_points - 1; 1846 FT_Byte* src_tag = left->tags + left->num_points - 1; 1847 1848 1849 while ( src_point >= left->points + left->start ) 1850 { 1851 *dst_point = *src_point; 1852 *dst_tag = *src_tag; 1853 1854 if ( open ) 1855 dst_tag[0] &= ~FT_STROKE_TAG_BEGIN_END; 1856 else 1857 { 1858 FT_Byte ttag = 1859 (FT_Byte)( dst_tag[0] & FT_STROKE_TAG_BEGIN_END ); 1860 1861 1862 /* switch begin/end tags if necessary */ 1863 if ( ttag == FT_STROKE_TAG_BEGIN || 1864 ttag == FT_STROKE_TAG_END ) 1865 dst_tag[0] ^= FT_STROKE_TAG_BEGIN_END; 1866 } 1867 1868 src_point--; 1869 src_tag--; 1870 dst_point++; 1871 dst_tag++; 1872 } 1873 } 1874 1875 left->num_points = (FT_UInt)left->start; 1876 right->num_points += (FT_UInt)new_points; 1877 1878 right->movable = FALSE; 1879 left->movable = FALSE; 1880 } 1881 1882 Exit: 1883 return error; 1884 } 1885 1886 1887 /* documentation is in ftstroke.h */ 1888 1889 /* there's a lot of magic in this function! */ 1890 FT_EXPORT_DEF( FT_Error ) FT_Stroker_EndSubPath(FT_Stroker stroker)1891 FT_Stroker_EndSubPath( FT_Stroker stroker ) 1892 { 1893 FT_Error error = FT_Err_Ok; 1894 1895 1896 if ( !stroker ) 1897 { 1898 error = FT_THROW( Invalid_Argument ); 1899 goto Exit; 1900 } 1901 1902 if ( stroker->subpath_open ) 1903 { 1904 FT_StrokeBorder right = stroker->borders; 1905 1906 1907 /* All right, this is an opened path, we need to add a cap between */ 1908 /* right & left, add the reverse of left, then add a final cap */ 1909 /* between left & right. */ 1910 error = ft_stroker_cap( stroker, stroker->angle_in, 0 ); 1911 if ( error ) 1912 goto Exit; 1913 1914 /* add reversed points from `left' to `right' */ 1915 error = ft_stroker_add_reverse_left( stroker, TRUE ); 1916 if ( error ) 1917 goto Exit; 1918 1919 /* now add the final cap */ 1920 stroker->center = stroker->subpath_start; 1921 error = ft_stroker_cap( stroker, 1922 stroker->subpath_angle + FT_ANGLE_PI, 0 ); 1923 if ( error ) 1924 goto Exit; 1925 1926 /* Now end the right subpath accordingly. The left one is */ 1927 /* rewind and doesn't need further processing. */ 1928 ft_stroke_border_close( right, FALSE ); 1929 } 1930 else 1931 { 1932 FT_Angle turn; 1933 FT_Int inside_side; 1934 1935 1936 /* close the path if needed */ 1937 if ( stroker->center.x != stroker->subpath_start.x || 1938 stroker->center.y != stroker->subpath_start.y ) 1939 { 1940 error = FT_Stroker_LineTo( stroker, &stroker->subpath_start ); 1941 if ( error ) 1942 goto Exit; 1943 } 1944 1945 /* process the corner */ 1946 stroker->angle_out = stroker->subpath_angle; 1947 turn = FT_Angle_Diff( stroker->angle_in, 1948 stroker->angle_out ); 1949 1950 /* no specific corner processing is required if the turn is 0 */ 1951 if ( turn != 0 ) 1952 { 1953 /* when we turn to the right, the inside side is 0 */ 1954 /* otherwise, the inside side is 1 */ 1955 inside_side = ( turn < 0 ); 1956 1957 error = ft_stroker_inside( stroker, 1958 inside_side, 1959 stroker->subpath_line_length ); 1960 if ( error ) 1961 goto Exit; 1962 1963 /* process the outside side */ 1964 error = ft_stroker_outside( stroker, 1965 !inside_side, 1966 stroker->subpath_line_length ); 1967 if ( error ) 1968 goto Exit; 1969 } 1970 1971 /* then end our two subpaths */ 1972 ft_stroke_border_close( stroker->borders + 0, FALSE ); 1973 ft_stroke_border_close( stroker->borders + 1, TRUE ); 1974 } 1975 1976 Exit: 1977 return error; 1978 } 1979 1980 1981 /* documentation is in ftstroke.h */ 1982 1983 FT_EXPORT_DEF( FT_Error ) FT_Stroker_GetBorderCounts(FT_Stroker stroker,FT_StrokerBorder border,FT_UInt * anum_points,FT_UInt * anum_contours)1984 FT_Stroker_GetBorderCounts( FT_Stroker stroker, 1985 FT_StrokerBorder border, 1986 FT_UInt *anum_points, 1987 FT_UInt *anum_contours ) 1988 { 1989 FT_UInt num_points = 0, num_contours = 0; 1990 FT_Error error; 1991 1992 1993 if ( !stroker || border > 1 ) 1994 { 1995 error = FT_THROW( Invalid_Argument ); 1996 goto Exit; 1997 } 1998 1999 error = ft_stroke_border_get_counts( stroker->borders + border, 2000 &num_points, &num_contours ); 2001 Exit: 2002 if ( anum_points ) 2003 *anum_points = num_points; 2004 2005 if ( anum_contours ) 2006 *anum_contours = num_contours; 2007 2008 return error; 2009 } 2010 2011 2012 /* documentation is in ftstroke.h */ 2013 2014 FT_EXPORT_DEF( FT_Error ) FT_Stroker_GetCounts(FT_Stroker stroker,FT_UInt * anum_points,FT_UInt * anum_contours)2015 FT_Stroker_GetCounts( FT_Stroker stroker, 2016 FT_UInt *anum_points, 2017 FT_UInt *anum_contours ) 2018 { 2019 FT_UInt count1, count2, num_points = 0; 2020 FT_UInt count3, count4, num_contours = 0; 2021 FT_Error error; 2022 2023 2024 if ( !stroker ) 2025 { 2026 error = FT_THROW( Invalid_Argument ); 2027 goto Exit; 2028 } 2029 2030 error = ft_stroke_border_get_counts( stroker->borders + 0, 2031 &count1, &count2 ); 2032 if ( error ) 2033 goto Exit; 2034 2035 error = ft_stroke_border_get_counts( stroker->borders + 1, 2036 &count3, &count4 ); 2037 if ( error ) 2038 goto Exit; 2039 2040 num_points = count1 + count3; 2041 num_contours = count2 + count4; 2042 2043 Exit: 2044 if ( anum_points ) 2045 *anum_points = num_points; 2046 2047 if ( anum_contours ) 2048 *anum_contours = num_contours; 2049 2050 return error; 2051 } 2052 2053 2054 /* documentation is in ftstroke.h */ 2055 2056 FT_EXPORT_DEF( void ) FT_Stroker_ExportBorder(FT_Stroker stroker,FT_StrokerBorder border,FT_Outline * outline)2057 FT_Stroker_ExportBorder( FT_Stroker stroker, 2058 FT_StrokerBorder border, 2059 FT_Outline* outline ) 2060 { 2061 if ( !stroker || !outline ) 2062 return; 2063 2064 if ( border == FT_STROKER_BORDER_LEFT || 2065 border == FT_STROKER_BORDER_RIGHT ) 2066 { 2067 FT_StrokeBorder sborder = & stroker->borders[border]; 2068 2069 2070 if ( sborder->valid ) 2071 ft_stroke_border_export( sborder, outline ); 2072 } 2073 } 2074 2075 2076 /* documentation is in ftstroke.h */ 2077 2078 FT_EXPORT_DEF( void ) FT_Stroker_Export(FT_Stroker stroker,FT_Outline * outline)2079 FT_Stroker_Export( FT_Stroker stroker, 2080 FT_Outline* outline ) 2081 { 2082 FT_Stroker_ExportBorder( stroker, FT_STROKER_BORDER_LEFT, outline ); 2083 FT_Stroker_ExportBorder( stroker, FT_STROKER_BORDER_RIGHT, outline ); 2084 } 2085 2086 2087 /* documentation is in ftstroke.h */ 2088 2089 /* 2090 * The following is very similar to FT_Outline_Decompose, except 2091 * that we do support opened paths, and do not scale the outline. 2092 */ 2093 FT_EXPORT_DEF( FT_Error ) FT_Stroker_ParseOutline(FT_Stroker stroker,FT_Outline * outline,FT_Bool opened)2094 FT_Stroker_ParseOutline( FT_Stroker stroker, 2095 FT_Outline* outline, 2096 FT_Bool opened ) 2097 { 2098 FT_Vector v_last; 2099 FT_Vector v_control; 2100 FT_Vector v_start; 2101 2102 FT_Vector* point; 2103 FT_Vector* limit; 2104 char* tags; 2105 2106 FT_Error error; 2107 2108 FT_Int n; /* index of contour in outline */ 2109 FT_UInt first; /* index of first point in contour */ 2110 FT_Int tag; /* current point's state */ 2111 2112 2113 if ( !outline ) 2114 return FT_THROW( Invalid_Outline ); 2115 2116 if ( !stroker ) 2117 return FT_THROW( Invalid_Argument ); 2118 2119 FT_Stroker_Rewind( stroker ); 2120 2121 first = 0; 2122 2123 for ( n = 0; n < outline->n_contours; n++ ) 2124 { 2125 FT_UInt last; /* index of last point in contour */ 2126 2127 2128 last = (FT_UInt)outline->contours[n]; 2129 limit = outline->points + last; 2130 2131 /* skip empty points; we don't stroke these */ 2132 if ( last <= first ) 2133 { 2134 first = last + 1; 2135 continue; 2136 } 2137 2138 v_start = outline->points[first]; 2139 v_last = outline->points[last]; 2140 2141 v_control = v_start; 2142 2143 point = outline->points + first; 2144 tags = outline->tags + first; 2145 tag = FT_CURVE_TAG( tags[0] ); 2146 2147 /* A contour cannot start with a cubic control point! */ 2148 if ( tag == FT_CURVE_TAG_CUBIC ) 2149 goto Invalid_Outline; 2150 2151 /* check first point to determine origin */ 2152 if ( tag == FT_CURVE_TAG_CONIC ) 2153 { 2154 /* First point is conic control. Yes, this happens. */ 2155 if ( FT_CURVE_TAG( outline->tags[last] ) == FT_CURVE_TAG_ON ) 2156 { 2157 /* start at last point if it is on the curve */ 2158 v_start = v_last; 2159 limit--; 2160 } 2161 else 2162 { 2163 /* if both first and last points are conic, */ 2164 /* start at their middle */ 2165 v_start.x = ( v_start.x + v_last.x ) / 2; 2166 v_start.y = ( v_start.y + v_last.y ) / 2; 2167 } 2168 point--; 2169 tags--; 2170 } 2171 2172 error = FT_Stroker_BeginSubPath( stroker, &v_start, opened ); 2173 if ( error ) 2174 goto Exit; 2175 2176 while ( point < limit ) 2177 { 2178 point++; 2179 tags++; 2180 2181 tag = FT_CURVE_TAG( tags[0] ); 2182 switch ( tag ) 2183 { 2184 case FT_CURVE_TAG_ON: /* emit a single line_to */ 2185 { 2186 FT_Vector vec; 2187 2188 2189 vec.x = point->x; 2190 vec.y = point->y; 2191 2192 error = FT_Stroker_LineTo( stroker, &vec ); 2193 if ( error ) 2194 goto Exit; 2195 continue; 2196 } 2197 2198 case FT_CURVE_TAG_CONIC: /* consume conic arcs */ 2199 v_control.x = point->x; 2200 v_control.y = point->y; 2201 2202 Do_Conic: 2203 if ( point < limit ) 2204 { 2205 FT_Vector vec; 2206 FT_Vector v_middle; 2207 2208 2209 point++; 2210 tags++; 2211 tag = FT_CURVE_TAG( tags[0] ); 2212 2213 vec = point[0]; 2214 2215 if ( tag == FT_CURVE_TAG_ON ) 2216 { 2217 error = FT_Stroker_ConicTo( stroker, &v_control, &vec ); 2218 if ( error ) 2219 goto Exit; 2220 continue; 2221 } 2222 2223 if ( tag != FT_CURVE_TAG_CONIC ) 2224 goto Invalid_Outline; 2225 2226 v_middle.x = ( v_control.x + vec.x ) / 2; 2227 v_middle.y = ( v_control.y + vec.y ) / 2; 2228 2229 error = FT_Stroker_ConicTo( stroker, &v_control, &v_middle ); 2230 if ( error ) 2231 goto Exit; 2232 2233 v_control = vec; 2234 goto Do_Conic; 2235 } 2236 2237 error = FT_Stroker_ConicTo( stroker, &v_control, &v_start ); 2238 goto Close; 2239 2240 default: /* FT_CURVE_TAG_CUBIC */ 2241 { 2242 FT_Vector vec1, vec2; 2243 2244 2245 if ( point + 1 > limit || 2246 FT_CURVE_TAG( tags[1] ) != FT_CURVE_TAG_CUBIC ) 2247 goto Invalid_Outline; 2248 2249 point += 2; 2250 tags += 2; 2251 2252 vec1 = point[-2]; 2253 vec2 = point[-1]; 2254 2255 if ( point <= limit ) 2256 { 2257 FT_Vector vec; 2258 2259 2260 vec = point[0]; 2261 2262 error = FT_Stroker_CubicTo( stroker, &vec1, &vec2, &vec ); 2263 if ( error ) 2264 goto Exit; 2265 continue; 2266 } 2267 2268 error = FT_Stroker_CubicTo( stroker, &vec1, &vec2, &v_start ); 2269 goto Close; 2270 } 2271 } 2272 } 2273 2274 Close: 2275 if ( error ) 2276 goto Exit; 2277 2278 /* don't try to end the path if no segments have been generated */ 2279 if ( !stroker->first_point ) 2280 { 2281 error = FT_Stroker_EndSubPath( stroker ); 2282 if ( error ) 2283 goto Exit; 2284 } 2285 2286 first = last + 1; 2287 } 2288 2289 return FT_Err_Ok; 2290 2291 Exit: 2292 return error; 2293 2294 Invalid_Outline: 2295 return FT_THROW( Invalid_Outline ); 2296 } 2297 2298 2299 /* documentation is in ftstroke.h */ 2300 2301 FT_EXPORT_DEF( FT_Error ) FT_Glyph_Stroke(FT_Glyph * pglyph,FT_Stroker stroker,FT_Bool destroy)2302 FT_Glyph_Stroke( FT_Glyph *pglyph, 2303 FT_Stroker stroker, 2304 FT_Bool destroy ) 2305 { 2306 FT_Error error = FT_ERR( Invalid_Argument ); 2307 FT_Glyph glyph = NULL; 2308 2309 /* for FT_OUTLINE_GLYPH_CLASS_GET (in PIC mode) */ 2310 FT_Library library = stroker->library; 2311 2312 FT_UNUSED( library ); 2313 2314 2315 if ( !pglyph ) 2316 goto Exit; 2317 2318 glyph = *pglyph; 2319 if ( !glyph || glyph->clazz != FT_OUTLINE_GLYPH_CLASS_GET ) 2320 goto Exit; 2321 2322 { 2323 FT_Glyph copy; 2324 2325 2326 error = FT_Glyph_Copy( glyph, © ); 2327 if ( error ) 2328 goto Exit; 2329 2330 glyph = copy; 2331 } 2332 2333 { 2334 FT_OutlineGlyph oglyph = (FT_OutlineGlyph)glyph; 2335 FT_Outline* outline = &oglyph->outline; 2336 FT_UInt num_points, num_contours; 2337 2338 2339 error = FT_Stroker_ParseOutline( stroker, outline, FALSE ); 2340 if ( error ) 2341 goto Fail; 2342 2343 FT_Stroker_GetCounts( stroker, &num_points, &num_contours ); 2344 2345 FT_Outline_Done( glyph->library, outline ); 2346 2347 error = FT_Outline_New( glyph->library, 2348 num_points, 2349 (FT_Int)num_contours, 2350 outline ); 2351 if ( error ) 2352 goto Fail; 2353 2354 outline->n_points = 0; 2355 outline->n_contours = 0; 2356 2357 FT_Stroker_Export( stroker, outline ); 2358 } 2359 2360 if ( destroy ) 2361 FT_Done_Glyph( *pglyph ); 2362 2363 *pglyph = glyph; 2364 goto Exit; 2365 2366 Fail: 2367 FT_Done_Glyph( glyph ); 2368 glyph = NULL; 2369 2370 if ( !destroy ) 2371 *pglyph = NULL; 2372 2373 Exit: 2374 return error; 2375 } 2376 2377 2378 /* documentation is in ftstroke.h */ 2379 2380 FT_EXPORT_DEF( FT_Error ) FT_Glyph_StrokeBorder(FT_Glyph * pglyph,FT_Stroker stroker,FT_Bool inside,FT_Bool destroy)2381 FT_Glyph_StrokeBorder( FT_Glyph *pglyph, 2382 FT_Stroker stroker, 2383 FT_Bool inside, 2384 FT_Bool destroy ) 2385 { 2386 FT_Error error = FT_ERR( Invalid_Argument ); 2387 FT_Glyph glyph = NULL; 2388 2389 /* for FT_OUTLINE_GLYPH_CLASS_GET (in PIC mode) */ 2390 FT_Library library = stroker->library; 2391 2392 FT_UNUSED( library ); 2393 2394 2395 if ( !pglyph ) 2396 goto Exit; 2397 2398 glyph = *pglyph; 2399 if ( !glyph || glyph->clazz != FT_OUTLINE_GLYPH_CLASS_GET ) 2400 goto Exit; 2401 2402 { 2403 FT_Glyph copy; 2404 2405 2406 error = FT_Glyph_Copy( glyph, © ); 2407 if ( error ) 2408 goto Exit; 2409 2410 glyph = copy; 2411 } 2412 2413 { 2414 FT_OutlineGlyph oglyph = (FT_OutlineGlyph)glyph; 2415 FT_StrokerBorder border; 2416 FT_Outline* outline = &oglyph->outline; 2417 FT_UInt num_points, num_contours; 2418 2419 2420 border = FT_Outline_GetOutsideBorder( outline ); 2421 if ( inside ) 2422 { 2423 if ( border == FT_STROKER_BORDER_LEFT ) 2424 border = FT_STROKER_BORDER_RIGHT; 2425 else 2426 border = FT_STROKER_BORDER_LEFT; 2427 } 2428 2429 error = FT_Stroker_ParseOutline( stroker, outline, FALSE ); 2430 if ( error ) 2431 goto Fail; 2432 2433 FT_Stroker_GetBorderCounts( stroker, border, 2434 &num_points, &num_contours ); 2435 2436 FT_Outline_Done( glyph->library, outline ); 2437 2438 error = FT_Outline_New( glyph->library, 2439 num_points, 2440 (FT_Int)num_contours, 2441 outline ); 2442 if ( error ) 2443 goto Fail; 2444 2445 outline->n_points = 0; 2446 outline->n_contours = 0; 2447 2448 FT_Stroker_ExportBorder( stroker, border, outline ); 2449 } 2450 2451 if ( destroy ) 2452 FT_Done_Glyph( *pglyph ); 2453 2454 *pglyph = glyph; 2455 goto Exit; 2456 2457 Fail: 2458 FT_Done_Glyph( glyph ); 2459 glyph = NULL; 2460 2461 if ( !destroy ) 2462 *pglyph = NULL; 2463 2464 Exit: 2465 return error; 2466 } 2467 2468 2469 /* END */ 2470