1 /***************************************************************************/ 2 /* */ 3 /* ftstroke.c */ 4 /* */ 5 /* FreeType path stroker (body). */ 6 /* */ 7 /* Copyright 2002-2015 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 FT_ARRAY_COPY( outline->points + outline->n_points, 716 border->points, 717 border->num_points ); 718 719 /* copy tags */ 720 { 721 FT_UInt count = border->num_points; 722 FT_Byte* read = border->tags; 723 FT_Byte* write = (FT_Byte*)outline->tags + outline->n_points; 724 725 726 for ( ; count > 0; count--, read++, write++ ) 727 { 728 if ( *read & FT_STROKE_TAG_ON ) 729 *write = FT_CURVE_TAG_ON; 730 else if ( *read & FT_STROKE_TAG_CUBIC ) 731 *write = FT_CURVE_TAG_CUBIC; 732 else 733 *write = FT_CURVE_TAG_CONIC; 734 } 735 } 736 737 /* copy contours */ 738 { 739 FT_UInt count = border->num_points; 740 FT_Byte* tags = border->tags; 741 FT_Short* write = outline->contours + outline->n_contours; 742 FT_Short idx = (FT_Short)outline->n_points; 743 744 745 for ( ; count > 0; count--, tags++, idx++ ) 746 { 747 if ( *tags & FT_STROKE_TAG_END ) 748 { 749 *write++ = idx; 750 outline->n_contours++; 751 } 752 } 753 } 754 755 outline->n_points += (short)border->num_points; 756 757 FT_ASSERT( FT_Outline_Check( outline ) == 0 ); 758 } 759 760 761 /*************************************************************************/ 762 /*************************************************************************/ 763 /***** *****/ 764 /***** STROKER *****/ 765 /***** *****/ 766 /*************************************************************************/ 767 /*************************************************************************/ 768 769 #define FT_SIDE_TO_ROTATE( s ) ( FT_ANGLE_PI2 - (s) * FT_ANGLE_PI ) 770 771 typedef struct FT_StrokerRec_ 772 { 773 FT_Angle angle_in; /* direction into curr join */ 774 FT_Angle angle_out; /* direction out of join */ 775 FT_Vector center; /* current position */ 776 FT_Fixed line_length; /* length of last lineto */ 777 FT_Bool first_point; /* is this the start? */ 778 FT_Bool subpath_open; /* is the subpath open? */ 779 FT_Angle subpath_angle; /* subpath start direction */ 780 FT_Vector subpath_start; /* subpath start position */ 781 FT_Fixed subpath_line_length; /* subpath start lineto len */ 782 FT_Bool handle_wide_strokes; /* use wide strokes logic? */ 783 784 FT_Stroker_LineCap line_cap; 785 FT_Stroker_LineJoin line_join; 786 FT_Stroker_LineJoin line_join_saved; 787 FT_Fixed miter_limit; 788 FT_Fixed radius; 789 790 FT_StrokeBorderRec borders[2]; 791 FT_Library library; 792 793 } FT_StrokerRec; 794 795 796 /* documentation is in ftstroke.h */ 797 798 FT_EXPORT_DEF( FT_Error ) FT_Stroker_New(FT_Library library,FT_Stroker * astroker)799 FT_Stroker_New( FT_Library library, 800 FT_Stroker *astroker ) 801 { 802 FT_Error error; /* assigned in FT_NEW */ 803 FT_Memory memory; 804 FT_Stroker stroker = NULL; 805 806 807 if ( !library ) 808 return FT_THROW( Invalid_Library_Handle ); 809 810 if ( !astroker ) 811 return FT_THROW( Invalid_Argument ); 812 813 memory = library->memory; 814 815 if ( !FT_NEW( stroker ) ) 816 { 817 stroker->library = library; 818 819 ft_stroke_border_init( &stroker->borders[0], memory ); 820 ft_stroke_border_init( &stroker->borders[1], memory ); 821 } 822 823 *astroker = stroker; 824 825 return error; 826 } 827 828 829 /* documentation is in ftstroke.h */ 830 831 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)832 FT_Stroker_Set( FT_Stroker stroker, 833 FT_Fixed radius, 834 FT_Stroker_LineCap line_cap, 835 FT_Stroker_LineJoin line_join, 836 FT_Fixed miter_limit ) 837 { 838 if ( !stroker ) 839 return; 840 841 stroker->radius = radius; 842 stroker->line_cap = line_cap; 843 stroker->line_join = line_join; 844 stroker->miter_limit = miter_limit; 845 846 /* ensure miter limit has sensible value */ 847 if ( stroker->miter_limit < 0x10000L ) 848 stroker->miter_limit = 0x10000L; 849 850 /* save line join style: */ 851 /* line join style can be temporarily changed when stroking curves */ 852 stroker->line_join_saved = line_join; 853 854 FT_Stroker_Rewind( stroker ); 855 } 856 857 858 /* documentation is in ftstroke.h */ 859 860 FT_EXPORT_DEF( void ) FT_Stroker_Rewind(FT_Stroker stroker)861 FT_Stroker_Rewind( FT_Stroker stroker ) 862 { 863 if ( stroker ) 864 { 865 ft_stroke_border_reset( &stroker->borders[0] ); 866 ft_stroke_border_reset( &stroker->borders[1] ); 867 } 868 } 869 870 871 /* documentation is in ftstroke.h */ 872 873 FT_EXPORT_DEF( void ) FT_Stroker_Done(FT_Stroker stroker)874 FT_Stroker_Done( FT_Stroker stroker ) 875 { 876 if ( stroker ) 877 { 878 FT_Memory memory = stroker->library->memory; 879 880 881 ft_stroke_border_done( &stroker->borders[0] ); 882 ft_stroke_border_done( &stroker->borders[1] ); 883 884 stroker->library = NULL; 885 FT_FREE( stroker ); 886 } 887 } 888 889 890 /* create a circular arc at a corner or cap */ 891 static FT_Error ft_stroker_arcto(FT_Stroker stroker,FT_Int side)892 ft_stroker_arcto( FT_Stroker stroker, 893 FT_Int side ) 894 { 895 FT_Angle total, rotate; 896 FT_Fixed radius = stroker->radius; 897 FT_Error error = FT_Err_Ok; 898 FT_StrokeBorder border = stroker->borders + side; 899 900 901 rotate = FT_SIDE_TO_ROTATE( side ); 902 903 total = FT_Angle_Diff( stroker->angle_in, stroker->angle_out ); 904 if ( total == FT_ANGLE_PI ) 905 total = -rotate * 2; 906 907 error = ft_stroke_border_arcto( border, 908 &stroker->center, 909 radius, 910 stroker->angle_in + rotate, 911 total ); 912 border->movable = FALSE; 913 return error; 914 } 915 916 917 /* add a cap at the end of an opened path */ 918 static FT_Error ft_stroker_cap(FT_Stroker stroker,FT_Angle angle,FT_Int side)919 ft_stroker_cap( FT_Stroker stroker, 920 FT_Angle angle, 921 FT_Int side ) 922 { 923 FT_Error error = FT_Err_Ok; 924 925 926 if ( stroker->line_cap == FT_STROKER_LINECAP_ROUND ) 927 { 928 /* add a round cap */ 929 stroker->angle_in = angle; 930 stroker->angle_out = angle + FT_ANGLE_PI; 931 932 error = ft_stroker_arcto( stroker, side ); 933 } 934 else if ( stroker->line_cap == FT_STROKER_LINECAP_SQUARE ) 935 { 936 /* add a square cap */ 937 FT_Vector delta, delta2; 938 FT_Angle rotate = FT_SIDE_TO_ROTATE( side ); 939 FT_Fixed radius = stroker->radius; 940 FT_StrokeBorder border = stroker->borders + side; 941 942 943 FT_Vector_From_Polar( &delta2, radius, angle + rotate ); 944 FT_Vector_From_Polar( &delta, radius, angle ); 945 946 delta.x += stroker->center.x + delta2.x; 947 delta.y += stroker->center.y + delta2.y; 948 949 error = ft_stroke_border_lineto( border, &delta, FALSE ); 950 if ( error ) 951 goto Exit; 952 953 FT_Vector_From_Polar( &delta2, radius, angle - rotate ); 954 FT_Vector_From_Polar( &delta, radius, angle ); 955 956 delta.x += delta2.x + stroker->center.x; 957 delta.y += delta2.y + stroker->center.y; 958 959 error = ft_stroke_border_lineto( border, &delta, FALSE ); 960 } 961 else if ( stroker->line_cap == FT_STROKER_LINECAP_BUTT ) 962 { 963 /* add a butt ending */ 964 FT_Vector delta; 965 FT_Angle rotate = FT_SIDE_TO_ROTATE( side ); 966 FT_Fixed radius = stroker->radius; 967 FT_StrokeBorder border = stroker->borders + side; 968 969 970 FT_Vector_From_Polar( &delta, radius, angle + rotate ); 971 972 delta.x += stroker->center.x; 973 delta.y += stroker->center.y; 974 975 error = ft_stroke_border_lineto( border, &delta, FALSE ); 976 if ( error ) 977 goto Exit; 978 979 FT_Vector_From_Polar( &delta, radius, angle - rotate ); 980 981 delta.x += stroker->center.x; 982 delta.y += stroker->center.y; 983 984 error = ft_stroke_border_lineto( border, &delta, FALSE ); 985 } 986 987 Exit: 988 return error; 989 } 990 991 992 /* process an inside corner, i.e. compute intersection */ 993 static FT_Error ft_stroker_inside(FT_Stroker stroker,FT_Int side,FT_Fixed line_length)994 ft_stroker_inside( FT_Stroker stroker, 995 FT_Int side, 996 FT_Fixed line_length ) 997 { 998 FT_StrokeBorder border = stroker->borders + side; 999 FT_Angle phi, theta, rotate; 1000 FT_Fixed length, thcos; 1001 FT_Vector delta; 1002 FT_Error error = FT_Err_Ok; 1003 FT_Bool intersect; /* use intersection of lines? */ 1004 1005 1006 rotate = FT_SIDE_TO_ROTATE( side ); 1007 1008 theta = FT_Angle_Diff( stroker->angle_in, stroker->angle_out ) / 2; 1009 1010 /* Only intersect borders if between two lineto's and both */ 1011 /* lines are long enough (line_length is zero for curves). */ 1012 /* Also avoid U-turns of nearly 180 degree. */ 1013 if ( !border->movable || line_length == 0 || 1014 theta > 0x59C000 || theta < -0x59C000 ) 1015 intersect = FALSE; 1016 else 1017 { 1018 /* compute minimum required length of lines */ 1019 FT_Fixed min_length = ft_pos_abs( FT_MulFix( stroker->radius, 1020 FT_Tan( theta ) ) ); 1021 1022 1023 intersect = FT_BOOL( min_length && 1024 stroker->line_length >= min_length && 1025 line_length >= min_length ); 1026 } 1027 1028 if ( !intersect ) 1029 { 1030 FT_Vector_From_Polar( &delta, stroker->radius, 1031 stroker->angle_out + rotate ); 1032 delta.x += stroker->center.x; 1033 delta.y += stroker->center.y; 1034 1035 border->movable = FALSE; 1036 } 1037 else 1038 { 1039 /* compute median angle */ 1040 phi = stroker->angle_in + theta; 1041 1042 thcos = FT_Cos( theta ); 1043 1044 length = FT_DivFix( stroker->radius, thcos ); 1045 1046 FT_Vector_From_Polar( &delta, length, phi + rotate ); 1047 delta.x += stroker->center.x; 1048 delta.y += stroker->center.y; 1049 } 1050 1051 error = ft_stroke_border_lineto( border, &delta, FALSE ); 1052 1053 return error; 1054 } 1055 1056 1057 /* process an outside corner, i.e. compute bevel/miter/round */ 1058 static FT_Error ft_stroker_outside(FT_Stroker stroker,FT_Int side,FT_Fixed line_length)1059 ft_stroker_outside( FT_Stroker stroker, 1060 FT_Int side, 1061 FT_Fixed line_length ) 1062 { 1063 FT_StrokeBorder border = stroker->borders + side; 1064 FT_Error error; 1065 FT_Angle rotate; 1066 1067 1068 if ( stroker->line_join == FT_STROKER_LINEJOIN_ROUND ) 1069 error = ft_stroker_arcto( stroker, side ); 1070 else 1071 { 1072 /* this is a mitered (pointed) or beveled (truncated) corner */ 1073 FT_Fixed sigma = 0, radius = stroker->radius; 1074 FT_Angle theta = 0, phi = 0; 1075 FT_Fixed thcos = 0; 1076 FT_Bool bevel, fixed_bevel; 1077 1078 1079 rotate = FT_SIDE_TO_ROTATE( side ); 1080 1081 bevel = 1082 FT_BOOL( stroker->line_join == FT_STROKER_LINEJOIN_BEVEL ); 1083 1084 fixed_bevel = 1085 FT_BOOL( stroker->line_join != FT_STROKER_LINEJOIN_MITER_VARIABLE ); 1086 1087 if ( !bevel ) 1088 { 1089 theta = FT_Angle_Diff( stroker->angle_in, stroker->angle_out ); 1090 1091 if ( theta == FT_ANGLE_PI ) 1092 { 1093 theta = rotate; 1094 phi = stroker->angle_in; 1095 } 1096 else 1097 { 1098 theta /= 2; 1099 phi = stroker->angle_in + theta + rotate; 1100 } 1101 1102 thcos = FT_Cos( theta ); 1103 sigma = FT_MulFix( stroker->miter_limit, thcos ); 1104 1105 /* is miter limit exceeded? */ 1106 if ( sigma < 0x10000L ) 1107 { 1108 /* don't create variable bevels for very small deviations; */ 1109 /* FT_Sin(x) = 0 for x <= 57 */ 1110 if ( fixed_bevel || ft_pos_abs( theta ) > 57 ) 1111 bevel = TRUE; 1112 } 1113 } 1114 1115 if ( bevel ) /* this is a bevel (broken angle) */ 1116 { 1117 if ( fixed_bevel ) 1118 { 1119 /* the outer corners are simply joined together */ 1120 FT_Vector delta; 1121 1122 1123 /* add bevel */ 1124 FT_Vector_From_Polar( &delta, 1125 radius, 1126 stroker->angle_out + rotate ); 1127 delta.x += stroker->center.x; 1128 delta.y += stroker->center.y; 1129 1130 border->movable = FALSE; 1131 error = ft_stroke_border_lineto( border, &delta, FALSE ); 1132 } 1133 else /* variable bevel */ 1134 { 1135 /* the miter is truncated */ 1136 FT_Vector middle, delta; 1137 FT_Fixed length; 1138 1139 1140 /* compute middle point */ 1141 FT_Vector_From_Polar( &middle, 1142 FT_MulFix( radius, stroker->miter_limit ), 1143 phi ); 1144 middle.x += stroker->center.x; 1145 middle.y += stroker->center.y; 1146 1147 /* compute first angle point */ 1148 length = FT_MulDiv( radius, 0x10000L - sigma, 1149 ft_pos_abs( FT_Sin( theta ) ) ); 1150 1151 FT_Vector_From_Polar( &delta, length, phi + rotate ); 1152 delta.x += middle.x; 1153 delta.y += middle.y; 1154 1155 error = ft_stroke_border_lineto( border, &delta, FALSE ); 1156 if ( error ) 1157 goto Exit; 1158 1159 /* compute second angle point */ 1160 FT_Vector_From_Polar( &delta, length, phi - rotate ); 1161 delta.x += middle.x; 1162 delta.y += middle.y; 1163 1164 error = ft_stroke_border_lineto( border, &delta, FALSE ); 1165 if ( error ) 1166 goto Exit; 1167 1168 /* finally, add an end point; only needed if not lineto */ 1169 /* (line_length is zero for curves) */ 1170 if ( line_length == 0 ) 1171 { 1172 FT_Vector_From_Polar( &delta, 1173 radius, 1174 stroker->angle_out + rotate ); 1175 1176 delta.x += stroker->center.x; 1177 delta.y += stroker->center.y; 1178 1179 error = ft_stroke_border_lineto( border, &delta, FALSE ); 1180 } 1181 } 1182 } 1183 else /* this is a miter (intersection) */ 1184 { 1185 FT_Fixed length; 1186 FT_Vector delta; 1187 1188 1189 length = FT_DivFix( stroker->radius, thcos ); 1190 1191 FT_Vector_From_Polar( &delta, length, phi ); 1192 delta.x += stroker->center.x; 1193 delta.y += stroker->center.y; 1194 1195 error = ft_stroke_border_lineto( border, &delta, FALSE ); 1196 if ( error ) 1197 goto Exit; 1198 1199 /* now add an end point; only needed if not lineto */ 1200 /* (line_length is zero for curves) */ 1201 if ( line_length == 0 ) 1202 { 1203 FT_Vector_From_Polar( &delta, 1204 stroker->radius, 1205 stroker->angle_out + rotate ); 1206 delta.x += stroker->center.x; 1207 delta.y += stroker->center.y; 1208 1209 error = ft_stroke_border_lineto( border, &delta, FALSE ); 1210 } 1211 } 1212 } 1213 1214 Exit: 1215 return error; 1216 } 1217 1218 1219 static FT_Error ft_stroker_process_corner(FT_Stroker stroker,FT_Fixed line_length)1220 ft_stroker_process_corner( FT_Stroker stroker, 1221 FT_Fixed line_length ) 1222 { 1223 FT_Error error = FT_Err_Ok; 1224 FT_Angle turn; 1225 FT_Int inside_side; 1226 1227 1228 turn = FT_Angle_Diff( stroker->angle_in, stroker->angle_out ); 1229 1230 /* no specific corner processing is required if the turn is 0 */ 1231 if ( turn == 0 ) 1232 goto Exit; 1233 1234 /* when we turn to the right, the inside side is 0 */ 1235 /* otherwise, the inside side is 1 */ 1236 inside_side = ( turn < 0 ); 1237 1238 /* process the inside side */ 1239 error = ft_stroker_inside( stroker, inside_side, line_length ); 1240 if ( error ) 1241 goto Exit; 1242 1243 /* process the outside side */ 1244 error = ft_stroker_outside( stroker, !inside_side, line_length ); 1245 1246 Exit: 1247 return error; 1248 } 1249 1250 1251 /* add two points to the left and right borders corresponding to the */ 1252 /* start of the subpath */ 1253 static FT_Error ft_stroker_subpath_start(FT_Stroker stroker,FT_Angle start_angle,FT_Fixed line_length)1254 ft_stroker_subpath_start( FT_Stroker stroker, 1255 FT_Angle start_angle, 1256 FT_Fixed line_length ) 1257 { 1258 FT_Vector delta; 1259 FT_Vector point; 1260 FT_Error error; 1261 FT_StrokeBorder border; 1262 1263 1264 FT_Vector_From_Polar( &delta, stroker->radius, 1265 start_angle + FT_ANGLE_PI2 ); 1266 1267 point.x = stroker->center.x + delta.x; 1268 point.y = stroker->center.y + delta.y; 1269 1270 border = stroker->borders; 1271 error = ft_stroke_border_moveto( border, &point ); 1272 if ( error ) 1273 goto Exit; 1274 1275 point.x = stroker->center.x - delta.x; 1276 point.y = stroker->center.y - delta.y; 1277 1278 border++; 1279 error = ft_stroke_border_moveto( border, &point ); 1280 1281 /* save angle, position, and line length for last join */ 1282 /* (line_length is zero for curves) */ 1283 stroker->subpath_angle = start_angle; 1284 stroker->first_point = FALSE; 1285 stroker->subpath_line_length = line_length; 1286 1287 Exit: 1288 return error; 1289 } 1290 1291 1292 /* documentation is in ftstroke.h */ 1293 1294 FT_EXPORT_DEF( FT_Error ) FT_Stroker_LineTo(FT_Stroker stroker,FT_Vector * to)1295 FT_Stroker_LineTo( FT_Stroker stroker, 1296 FT_Vector* to ) 1297 { 1298 FT_Error error = FT_Err_Ok; 1299 FT_StrokeBorder border; 1300 FT_Vector delta; 1301 FT_Angle angle; 1302 FT_Int side; 1303 FT_Fixed line_length; 1304 1305 1306 if ( !stroker || !to ) 1307 return FT_THROW( Invalid_Argument ); 1308 1309 delta.x = to->x - stroker->center.x; 1310 delta.y = to->y - stroker->center.y; 1311 1312 /* a zero-length lineto is a no-op; avoid creating a spurious corner */ 1313 if ( delta.x == 0 && delta.y == 0 ) 1314 goto Exit; 1315 1316 /* compute length of line */ 1317 line_length = FT_Vector_Length( &delta ); 1318 1319 angle = FT_Atan2( delta.x, delta.y ); 1320 FT_Vector_From_Polar( &delta, stroker->radius, angle + FT_ANGLE_PI2 ); 1321 1322 /* process corner if necessary */ 1323 if ( stroker->first_point ) 1324 { 1325 /* This is the first segment of a subpath. We need to */ 1326 /* add a point to each border at their respective starting */ 1327 /* point locations. */ 1328 error = ft_stroker_subpath_start( stroker, angle, line_length ); 1329 if ( error ) 1330 goto Exit; 1331 } 1332 else 1333 { 1334 /* process the current corner */ 1335 stroker->angle_out = angle; 1336 error = ft_stroker_process_corner( stroker, line_length ); 1337 if ( error ) 1338 goto Exit; 1339 } 1340 1341 /* now add a line segment to both the `inside' and `outside' paths */ 1342 for ( border = stroker->borders, side = 1; side >= 0; side--, border++ ) 1343 { 1344 FT_Vector point; 1345 1346 1347 point.x = to->x + delta.x; 1348 point.y = to->y + delta.y; 1349 1350 /* the ends of lineto borders are movable */ 1351 error = ft_stroke_border_lineto( border, &point, TRUE ); 1352 if ( error ) 1353 goto Exit; 1354 1355 delta.x = -delta.x; 1356 delta.y = -delta.y; 1357 } 1358 1359 stroker->angle_in = angle; 1360 stroker->center = *to; 1361 stroker->line_length = line_length; 1362 1363 Exit: 1364 return error; 1365 } 1366 1367 1368 /* documentation is in ftstroke.h */ 1369 1370 FT_EXPORT_DEF( FT_Error ) FT_Stroker_ConicTo(FT_Stroker stroker,FT_Vector * control,FT_Vector * to)1371 FT_Stroker_ConicTo( FT_Stroker stroker, 1372 FT_Vector* control, 1373 FT_Vector* to ) 1374 { 1375 FT_Error error = FT_Err_Ok; 1376 FT_Vector bez_stack[34]; 1377 FT_Vector* arc; 1378 FT_Vector* limit = bez_stack + 30; 1379 FT_Bool first_arc = TRUE; 1380 1381 1382 if ( !stroker || !control || !to ) 1383 { 1384 error = FT_THROW( Invalid_Argument ); 1385 goto Exit; 1386 } 1387 1388 /* if all control points are coincident, this is a no-op; */ 1389 /* avoid creating a spurious corner */ 1390 if ( FT_IS_SMALL( stroker->center.x - control->x ) && 1391 FT_IS_SMALL( stroker->center.y - control->y ) && 1392 FT_IS_SMALL( control->x - to->x ) && 1393 FT_IS_SMALL( control->y - to->y ) ) 1394 { 1395 stroker->center = *to; 1396 goto Exit; 1397 } 1398 1399 arc = bez_stack; 1400 arc[0] = *to; 1401 arc[1] = *control; 1402 arc[2] = stroker->center; 1403 1404 while ( arc >= bez_stack ) 1405 { 1406 FT_Angle angle_in, angle_out; 1407 1408 1409 /* initialize with current direction */ 1410 angle_in = angle_out = stroker->angle_in; 1411 1412 if ( arc < limit && 1413 !ft_conic_is_small_enough( arc, &angle_in, &angle_out ) ) 1414 { 1415 if ( stroker->first_point ) 1416 stroker->angle_in = angle_in; 1417 1418 ft_conic_split( arc ); 1419 arc += 2; 1420 continue; 1421 } 1422 1423 if ( first_arc ) 1424 { 1425 first_arc = FALSE; 1426 1427 /* process corner if necessary */ 1428 if ( stroker->first_point ) 1429 error = ft_stroker_subpath_start( stroker, angle_in, 0 ); 1430 else 1431 { 1432 stroker->angle_out = angle_in; 1433 error = ft_stroker_process_corner( stroker, 0 ); 1434 } 1435 } 1436 else if ( ft_pos_abs( FT_Angle_Diff( stroker->angle_in, angle_in ) ) > 1437 FT_SMALL_CONIC_THRESHOLD / 4 ) 1438 { 1439 /* if the deviation from one arc to the next is too great, */ 1440 /* add a round corner */ 1441 stroker->center = arc[2]; 1442 stroker->angle_out = angle_in; 1443 stroker->line_join = FT_STROKER_LINEJOIN_ROUND; 1444 1445 error = ft_stroker_process_corner( stroker, 0 ); 1446 1447 /* reinstate line join style */ 1448 stroker->line_join = stroker->line_join_saved; 1449 } 1450 1451 if ( error ) 1452 goto Exit; 1453 1454 /* the arc's angle is small enough; we can add it directly to each */ 1455 /* border */ 1456 { 1457 FT_Vector ctrl, end; 1458 FT_Angle theta, phi, rotate, alpha0 = 0; 1459 FT_Fixed length; 1460 FT_StrokeBorder border; 1461 FT_Int side; 1462 1463 1464 theta = FT_Angle_Diff( angle_in, angle_out ) / 2; 1465 phi = angle_in + theta; 1466 length = FT_DivFix( stroker->radius, FT_Cos( theta ) ); 1467 1468 /* compute direction of original arc */ 1469 if ( stroker->handle_wide_strokes ) 1470 alpha0 = FT_Atan2( arc[0].x - arc[2].x, arc[0].y - arc[2].y ); 1471 1472 for ( border = stroker->borders, side = 0; 1473 side <= 1; 1474 side++, border++ ) 1475 { 1476 rotate = FT_SIDE_TO_ROTATE( side ); 1477 1478 /* compute control point */ 1479 FT_Vector_From_Polar( &ctrl, length, phi + rotate ); 1480 ctrl.x += arc[1].x; 1481 ctrl.y += arc[1].y; 1482 1483 /* compute end point */ 1484 FT_Vector_From_Polar( &end, stroker->radius, angle_out + rotate ); 1485 end.x += arc[0].x; 1486 end.y += arc[0].y; 1487 1488 if ( stroker->handle_wide_strokes ) 1489 { 1490 FT_Vector start; 1491 FT_Angle alpha1; 1492 1493 1494 /* determine whether the border radius is greater than the */ 1495 /* radius of curvature of the original arc */ 1496 start = border->points[border->num_points - 1]; 1497 1498 alpha1 = FT_Atan2( end.x - start.x, end.y - start.y ); 1499 1500 /* is the direction of the border arc opposite to */ 1501 /* that of the original arc? */ 1502 if ( ft_pos_abs( FT_Angle_Diff( alpha0, alpha1 ) ) > 1503 FT_ANGLE_PI / 2 ) 1504 { 1505 FT_Angle beta, gamma; 1506 FT_Vector bvec, delta; 1507 FT_Fixed blen, sinA, sinB, alen; 1508 1509 1510 /* use the sine rule to find the intersection point */ 1511 beta = FT_Atan2( arc[2].x - start.x, arc[2].y - start.y ); 1512 gamma = FT_Atan2( arc[0].x - end.x, arc[0].y - end.y ); 1513 1514 bvec.x = end.x - start.x; 1515 bvec.y = end.y - start.y; 1516 1517 blen = FT_Vector_Length( &bvec ); 1518 1519 sinA = ft_pos_abs( FT_Sin( alpha1 - gamma ) ); 1520 sinB = ft_pos_abs( FT_Sin( beta - gamma ) ); 1521 1522 alen = FT_MulDiv( blen, sinA, sinB ); 1523 1524 FT_Vector_From_Polar( &delta, alen, beta ); 1525 delta.x += start.x; 1526 delta.y += start.y; 1527 1528 /* circumnavigate the negative sector backwards */ 1529 border->movable = FALSE; 1530 error = ft_stroke_border_lineto( border, &delta, FALSE ); 1531 if ( error ) 1532 goto Exit; 1533 error = ft_stroke_border_lineto( border, &end, FALSE ); 1534 if ( error ) 1535 goto Exit; 1536 error = ft_stroke_border_conicto( border, &ctrl, &start ); 1537 if ( error ) 1538 goto Exit; 1539 /* and then move to the endpoint */ 1540 error = ft_stroke_border_lineto( border, &end, FALSE ); 1541 if ( error ) 1542 goto Exit; 1543 1544 continue; 1545 } 1546 1547 /* else fall through */ 1548 } 1549 1550 /* simply add an arc */ 1551 error = ft_stroke_border_conicto( border, &ctrl, &end ); 1552 if ( error ) 1553 goto Exit; 1554 } 1555 } 1556 1557 arc -= 2; 1558 1559 stroker->angle_in = angle_out; 1560 } 1561 1562 stroker->center = *to; 1563 1564 Exit: 1565 return error; 1566 } 1567 1568 1569 /* documentation is in ftstroke.h */ 1570 1571 FT_EXPORT_DEF( FT_Error ) FT_Stroker_CubicTo(FT_Stroker stroker,FT_Vector * control1,FT_Vector * control2,FT_Vector * to)1572 FT_Stroker_CubicTo( FT_Stroker stroker, 1573 FT_Vector* control1, 1574 FT_Vector* control2, 1575 FT_Vector* to ) 1576 { 1577 FT_Error error = FT_Err_Ok; 1578 FT_Vector bez_stack[37]; 1579 FT_Vector* arc; 1580 FT_Vector* limit = bez_stack + 32; 1581 FT_Bool first_arc = TRUE; 1582 1583 1584 if ( !stroker || !control1 || !control2 || !to ) 1585 { 1586 error = FT_THROW( Invalid_Argument ); 1587 goto Exit; 1588 } 1589 1590 /* if all control points are coincident, this is a no-op; */ 1591 /* avoid creating a spurious corner */ 1592 if ( FT_IS_SMALL( stroker->center.x - control1->x ) && 1593 FT_IS_SMALL( stroker->center.y - control1->y ) && 1594 FT_IS_SMALL( control1->x - control2->x ) && 1595 FT_IS_SMALL( control1->y - control2->y ) && 1596 FT_IS_SMALL( control2->x - to->x ) && 1597 FT_IS_SMALL( control2->y - to->y ) ) 1598 { 1599 stroker->center = *to; 1600 goto Exit; 1601 } 1602 1603 arc = bez_stack; 1604 arc[0] = *to; 1605 arc[1] = *control2; 1606 arc[2] = *control1; 1607 arc[3] = stroker->center; 1608 1609 while ( arc >= bez_stack ) 1610 { 1611 FT_Angle angle_in, angle_mid, angle_out; 1612 1613 1614 /* initialize with current direction */ 1615 angle_in = angle_out = angle_mid = stroker->angle_in; 1616 1617 if ( arc < limit && 1618 !ft_cubic_is_small_enough( arc, &angle_in, 1619 &angle_mid, &angle_out ) ) 1620 { 1621 if ( stroker->first_point ) 1622 stroker->angle_in = angle_in; 1623 1624 ft_cubic_split( arc ); 1625 arc += 3; 1626 continue; 1627 } 1628 1629 if ( first_arc ) 1630 { 1631 first_arc = FALSE; 1632 1633 /* process corner if necessary */ 1634 if ( stroker->first_point ) 1635 error = ft_stroker_subpath_start( stroker, angle_in, 0 ); 1636 else 1637 { 1638 stroker->angle_out = angle_in; 1639 error = ft_stroker_process_corner( stroker, 0 ); 1640 } 1641 } 1642 else if ( ft_pos_abs( FT_Angle_Diff( stroker->angle_in, angle_in ) ) > 1643 FT_SMALL_CUBIC_THRESHOLD / 4 ) 1644 { 1645 /* if the deviation from one arc to the next is too great, */ 1646 /* add a round corner */ 1647 stroker->center = arc[3]; 1648 stroker->angle_out = angle_in; 1649 stroker->line_join = FT_STROKER_LINEJOIN_ROUND; 1650 1651 error = ft_stroker_process_corner( stroker, 0 ); 1652 1653 /* reinstate line join style */ 1654 stroker->line_join = stroker->line_join_saved; 1655 } 1656 1657 if ( error ) 1658 goto Exit; 1659 1660 /* the arc's angle is small enough; we can add it directly to each */ 1661 /* border */ 1662 { 1663 FT_Vector ctrl1, ctrl2, end; 1664 FT_Angle theta1, phi1, theta2, phi2, rotate, alpha0 = 0; 1665 FT_Fixed length1, length2; 1666 FT_StrokeBorder border; 1667 FT_Int side; 1668 1669 1670 theta1 = FT_Angle_Diff( angle_in, angle_mid ) / 2; 1671 theta2 = FT_Angle_Diff( angle_mid, angle_out ) / 2; 1672 phi1 = ft_angle_mean( angle_in, angle_mid ); 1673 phi2 = ft_angle_mean( angle_mid, angle_out ); 1674 length1 = FT_DivFix( stroker->radius, FT_Cos( theta1 ) ); 1675 length2 = FT_DivFix( stroker->radius, FT_Cos( theta2 ) ); 1676 1677 /* compute direction of original arc */ 1678 if ( stroker->handle_wide_strokes ) 1679 alpha0 = FT_Atan2( arc[0].x - arc[3].x, arc[0].y - arc[3].y ); 1680 1681 for ( border = stroker->borders, side = 0; 1682 side <= 1; 1683 side++, border++ ) 1684 { 1685 rotate = FT_SIDE_TO_ROTATE( side ); 1686 1687 /* compute control points */ 1688 FT_Vector_From_Polar( &ctrl1, length1, phi1 + rotate ); 1689 ctrl1.x += arc[2].x; 1690 ctrl1.y += arc[2].y; 1691 1692 FT_Vector_From_Polar( &ctrl2, length2, phi2 + rotate ); 1693 ctrl2.x += arc[1].x; 1694 ctrl2.y += arc[1].y; 1695 1696 /* compute end point */ 1697 FT_Vector_From_Polar( &end, stroker->radius, angle_out + rotate ); 1698 end.x += arc[0].x; 1699 end.y += arc[0].y; 1700 1701 if ( stroker->handle_wide_strokes ) 1702 { 1703 FT_Vector start; 1704 FT_Angle alpha1; 1705 1706 1707 /* determine whether the border radius is greater than the */ 1708 /* radius of curvature of the original arc */ 1709 start = border->points[border->num_points - 1]; 1710 1711 alpha1 = FT_Atan2( end.x - start.x, end.y - start.y ); 1712 1713 /* is the direction of the border arc opposite to */ 1714 /* that of the original arc? */ 1715 if ( ft_pos_abs( FT_Angle_Diff( alpha0, alpha1 ) ) > 1716 FT_ANGLE_PI / 2 ) 1717 { 1718 FT_Angle beta, gamma; 1719 FT_Vector bvec, delta; 1720 FT_Fixed blen, sinA, sinB, alen; 1721 1722 1723 /* use the sine rule to find the intersection point */ 1724 beta = FT_Atan2( arc[3].x - start.x, arc[3].y - start.y ); 1725 gamma = FT_Atan2( arc[0].x - end.x, arc[0].y - end.y ); 1726 1727 bvec.x = end.x - start.x; 1728 bvec.y = end.y - start.y; 1729 1730 blen = FT_Vector_Length( &bvec ); 1731 1732 sinA = ft_pos_abs( FT_Sin( alpha1 - gamma ) ); 1733 sinB = ft_pos_abs( FT_Sin( beta - gamma ) ); 1734 1735 alen = FT_MulDiv( blen, sinA, sinB ); 1736 1737 FT_Vector_From_Polar( &delta, alen, beta ); 1738 delta.x += start.x; 1739 delta.y += start.y; 1740 1741 /* circumnavigate the negative sector backwards */ 1742 border->movable = FALSE; 1743 error = ft_stroke_border_lineto( border, &delta, FALSE ); 1744 if ( error ) 1745 goto Exit; 1746 error = ft_stroke_border_lineto( border, &end, FALSE ); 1747 if ( error ) 1748 goto Exit; 1749 error = ft_stroke_border_cubicto( border, 1750 &ctrl2, 1751 &ctrl1, 1752 &start ); 1753 if ( error ) 1754 goto Exit; 1755 /* and then move to the endpoint */ 1756 error = ft_stroke_border_lineto( border, &end, FALSE ); 1757 if ( error ) 1758 goto Exit; 1759 1760 continue; 1761 } 1762 1763 /* else fall through */ 1764 } 1765 1766 /* simply add an arc */ 1767 error = ft_stroke_border_cubicto( border, &ctrl1, &ctrl2, &end ); 1768 if ( error ) 1769 goto Exit; 1770 } 1771 } 1772 1773 arc -= 3; 1774 1775 stroker->angle_in = angle_out; 1776 } 1777 1778 stroker->center = *to; 1779 1780 Exit: 1781 return error; 1782 } 1783 1784 1785 /* documentation is in ftstroke.h */ 1786 1787 FT_EXPORT_DEF( FT_Error ) FT_Stroker_BeginSubPath(FT_Stroker stroker,FT_Vector * to,FT_Bool open)1788 FT_Stroker_BeginSubPath( FT_Stroker stroker, 1789 FT_Vector* to, 1790 FT_Bool open ) 1791 { 1792 if ( !stroker || !to ) 1793 return FT_THROW( Invalid_Argument ); 1794 1795 /* We cannot process the first point, because there is not enough */ 1796 /* information regarding its corner/cap. The latter will be processed */ 1797 /* in the `FT_Stroker_EndSubPath' routine. */ 1798 /* */ 1799 stroker->first_point = TRUE; 1800 stroker->center = *to; 1801 stroker->subpath_open = open; 1802 1803 /* Determine if we need to check whether the border radius is greater */ 1804 /* than the radius of curvature of a curve, to handle this case */ 1805 /* specially. This is only required if bevel joins or butt caps may */ 1806 /* be created, because round & miter joins and round & square caps */ 1807 /* cover the negative sector created with wide strokes. */ 1808 stroker->handle_wide_strokes = 1809 FT_BOOL( stroker->line_join != FT_STROKER_LINEJOIN_ROUND || 1810 ( stroker->subpath_open && 1811 stroker->line_cap == FT_STROKER_LINECAP_BUTT ) ); 1812 1813 /* record the subpath start point for each border */ 1814 stroker->subpath_start = *to; 1815 1816 stroker->angle_in = 0; 1817 1818 return FT_Err_Ok; 1819 } 1820 1821 1822 static FT_Error ft_stroker_add_reverse_left(FT_Stroker stroker,FT_Bool open)1823 ft_stroker_add_reverse_left( FT_Stroker stroker, 1824 FT_Bool open ) 1825 { 1826 FT_StrokeBorder right = stroker->borders + 0; 1827 FT_StrokeBorder left = stroker->borders + 1; 1828 FT_Int new_points; 1829 FT_Error error = FT_Err_Ok; 1830 1831 1832 FT_ASSERT( left->start >= 0 ); 1833 1834 new_points = (FT_Int)left->num_points - left->start; 1835 if ( new_points > 0 ) 1836 { 1837 error = ft_stroke_border_grow( right, (FT_UInt)new_points ); 1838 if ( error ) 1839 goto Exit; 1840 1841 { 1842 FT_Vector* dst_point = right->points + right->num_points; 1843 FT_Byte* dst_tag = right->tags + right->num_points; 1844 FT_Vector* src_point = left->points + left->num_points - 1; 1845 FT_Byte* src_tag = left->tags + left->num_points - 1; 1846 1847 1848 while ( src_point >= left->points + left->start ) 1849 { 1850 *dst_point = *src_point; 1851 *dst_tag = *src_tag; 1852 1853 if ( open ) 1854 dst_tag[0] &= ~FT_STROKE_TAG_BEGIN_END; 1855 else 1856 { 1857 FT_Byte ttag = 1858 (FT_Byte)( dst_tag[0] & FT_STROKE_TAG_BEGIN_END ); 1859 1860 1861 /* switch begin/end tags if necessary */ 1862 if ( ttag == FT_STROKE_TAG_BEGIN || 1863 ttag == FT_STROKE_TAG_END ) 1864 dst_tag[0] ^= FT_STROKE_TAG_BEGIN_END; 1865 } 1866 1867 src_point--; 1868 src_tag--; 1869 dst_point++; 1870 dst_tag++; 1871 } 1872 } 1873 1874 left->num_points = (FT_UInt)left->start; 1875 right->num_points += (FT_UInt)new_points; 1876 1877 right->movable = FALSE; 1878 left->movable = FALSE; 1879 } 1880 1881 Exit: 1882 return error; 1883 } 1884 1885 1886 /* documentation is in ftstroke.h */ 1887 1888 /* there's a lot of magic in this function! */ 1889 FT_EXPORT_DEF( FT_Error ) FT_Stroker_EndSubPath(FT_Stroker stroker)1890 FT_Stroker_EndSubPath( FT_Stroker stroker ) 1891 { 1892 FT_Error error = FT_Err_Ok; 1893 1894 1895 if ( !stroker ) 1896 { 1897 error = FT_THROW( Invalid_Argument ); 1898 goto Exit; 1899 } 1900 1901 if ( stroker->subpath_open ) 1902 { 1903 FT_StrokeBorder right = stroker->borders; 1904 1905 1906 /* All right, this is an opened path, we need to add a cap between */ 1907 /* right & left, add the reverse of left, then add a final cap */ 1908 /* between left & right. */ 1909 error = ft_stroker_cap( stroker, stroker->angle_in, 0 ); 1910 if ( error ) 1911 goto Exit; 1912 1913 /* add reversed points from `left' to `right' */ 1914 error = ft_stroker_add_reverse_left( stroker, TRUE ); 1915 if ( error ) 1916 goto Exit; 1917 1918 /* now add the final cap */ 1919 stroker->center = stroker->subpath_start; 1920 error = ft_stroker_cap( stroker, 1921 stroker->subpath_angle + FT_ANGLE_PI, 0 ); 1922 if ( error ) 1923 goto Exit; 1924 1925 /* Now end the right subpath accordingly. The left one is */ 1926 /* rewind and doesn't need further processing. */ 1927 ft_stroke_border_close( right, FALSE ); 1928 } 1929 else 1930 { 1931 FT_Angle turn; 1932 FT_Int inside_side; 1933 1934 1935 /* close the path if needed */ 1936 if ( stroker->center.x != stroker->subpath_start.x || 1937 stroker->center.y != stroker->subpath_start.y ) 1938 { 1939 error = FT_Stroker_LineTo( stroker, &stroker->subpath_start ); 1940 if ( error ) 1941 goto Exit; 1942 } 1943 1944 /* process the corner */ 1945 stroker->angle_out = stroker->subpath_angle; 1946 turn = FT_Angle_Diff( stroker->angle_in, 1947 stroker->angle_out ); 1948 1949 /* no specific corner processing is required if the turn is 0 */ 1950 if ( turn != 0 ) 1951 { 1952 /* when we turn to the right, the inside side is 0 */ 1953 /* otherwise, the inside side is 1 */ 1954 inside_side = ( turn < 0 ); 1955 1956 error = ft_stroker_inside( stroker, 1957 inside_side, 1958 stroker->subpath_line_length ); 1959 if ( error ) 1960 goto Exit; 1961 1962 /* process the outside side */ 1963 error = ft_stroker_outside( stroker, 1964 !inside_side, 1965 stroker->subpath_line_length ); 1966 if ( error ) 1967 goto Exit; 1968 } 1969 1970 /* then end our two subpaths */ 1971 ft_stroke_border_close( stroker->borders + 0, FALSE ); 1972 ft_stroke_border_close( stroker->borders + 1, TRUE ); 1973 } 1974 1975 Exit: 1976 return error; 1977 } 1978 1979 1980 /* documentation is in ftstroke.h */ 1981 1982 FT_EXPORT_DEF( FT_Error ) FT_Stroker_GetBorderCounts(FT_Stroker stroker,FT_StrokerBorder border,FT_UInt * anum_points,FT_UInt * anum_contours)1983 FT_Stroker_GetBorderCounts( FT_Stroker stroker, 1984 FT_StrokerBorder border, 1985 FT_UInt *anum_points, 1986 FT_UInt *anum_contours ) 1987 { 1988 FT_UInt num_points = 0, num_contours = 0; 1989 FT_Error error; 1990 1991 1992 if ( !stroker || border > 1 ) 1993 { 1994 error = FT_THROW( Invalid_Argument ); 1995 goto Exit; 1996 } 1997 1998 error = ft_stroke_border_get_counts( stroker->borders + border, 1999 &num_points, &num_contours ); 2000 Exit: 2001 if ( anum_points ) 2002 *anum_points = num_points; 2003 2004 if ( anum_contours ) 2005 *anum_contours = num_contours; 2006 2007 return error; 2008 } 2009 2010 2011 /* documentation is in ftstroke.h */ 2012 2013 FT_EXPORT_DEF( FT_Error ) FT_Stroker_GetCounts(FT_Stroker stroker,FT_UInt * anum_points,FT_UInt * anum_contours)2014 FT_Stroker_GetCounts( FT_Stroker stroker, 2015 FT_UInt *anum_points, 2016 FT_UInt *anum_contours ) 2017 { 2018 FT_UInt count1, count2, num_points = 0; 2019 FT_UInt count3, count4, num_contours = 0; 2020 FT_Error error; 2021 2022 2023 if ( !stroker ) 2024 { 2025 error = FT_THROW( Invalid_Argument ); 2026 goto Exit; 2027 } 2028 2029 error = ft_stroke_border_get_counts( stroker->borders + 0, 2030 &count1, &count2 ); 2031 if ( error ) 2032 goto Exit; 2033 2034 error = ft_stroke_border_get_counts( stroker->borders + 1, 2035 &count3, &count4 ); 2036 if ( error ) 2037 goto Exit; 2038 2039 num_points = count1 + count3; 2040 num_contours = count2 + count4; 2041 2042 Exit: 2043 if ( anum_points ) 2044 *anum_points = num_points; 2045 2046 if ( anum_contours ) 2047 *anum_contours = num_contours; 2048 2049 return error; 2050 } 2051 2052 2053 /* documentation is in ftstroke.h */ 2054 2055 FT_EXPORT_DEF( void ) FT_Stroker_ExportBorder(FT_Stroker stroker,FT_StrokerBorder border,FT_Outline * outline)2056 FT_Stroker_ExportBorder( FT_Stroker stroker, 2057 FT_StrokerBorder border, 2058 FT_Outline* outline ) 2059 { 2060 if ( !stroker || !outline ) 2061 return; 2062 2063 if ( border == FT_STROKER_BORDER_LEFT || 2064 border == FT_STROKER_BORDER_RIGHT ) 2065 { 2066 FT_StrokeBorder sborder = & stroker->borders[border]; 2067 2068 2069 if ( sborder->valid ) 2070 ft_stroke_border_export( sborder, outline ); 2071 } 2072 } 2073 2074 2075 /* documentation is in ftstroke.h */ 2076 2077 FT_EXPORT_DEF( void ) FT_Stroker_Export(FT_Stroker stroker,FT_Outline * outline)2078 FT_Stroker_Export( FT_Stroker stroker, 2079 FT_Outline* outline ) 2080 { 2081 FT_Stroker_ExportBorder( stroker, FT_STROKER_BORDER_LEFT, outline ); 2082 FT_Stroker_ExportBorder( stroker, FT_STROKER_BORDER_RIGHT, outline ); 2083 } 2084 2085 2086 /* documentation is in ftstroke.h */ 2087 2088 /* 2089 * The following is very similar to FT_Outline_Decompose, except 2090 * that we do support opened paths, and do not scale the outline. 2091 */ 2092 FT_EXPORT_DEF( FT_Error ) FT_Stroker_ParseOutline(FT_Stroker stroker,FT_Outline * outline,FT_Bool opened)2093 FT_Stroker_ParseOutline( FT_Stroker stroker, 2094 FT_Outline* outline, 2095 FT_Bool opened ) 2096 { 2097 FT_Vector v_last; 2098 FT_Vector v_control; 2099 FT_Vector v_start; 2100 2101 FT_Vector* point; 2102 FT_Vector* limit; 2103 char* tags; 2104 2105 FT_Error error; 2106 2107 FT_Int n; /* index of contour in outline */ 2108 FT_UInt first; /* index of first point in contour */ 2109 FT_Int tag; /* current point's state */ 2110 2111 2112 if ( !outline ) 2113 return FT_THROW( Invalid_Outline ); 2114 2115 if ( !stroker ) 2116 return FT_THROW( Invalid_Argument ); 2117 2118 FT_Stroker_Rewind( stroker ); 2119 2120 first = 0; 2121 2122 for ( n = 0; n < outline->n_contours; n++ ) 2123 { 2124 FT_UInt last; /* index of last point in contour */ 2125 2126 2127 last = (FT_UInt)outline->contours[n]; 2128 limit = outline->points + last; 2129 2130 /* skip empty points; we don't stroke these */ 2131 if ( last <= first ) 2132 { 2133 first = last + 1; 2134 continue; 2135 } 2136 2137 v_start = outline->points[first]; 2138 v_last = outline->points[last]; 2139 2140 v_control = v_start; 2141 2142 point = outline->points + first; 2143 tags = outline->tags + first; 2144 tag = FT_CURVE_TAG( tags[0] ); 2145 2146 /* A contour cannot start with a cubic control point! */ 2147 if ( tag == FT_CURVE_TAG_CUBIC ) 2148 goto Invalid_Outline; 2149 2150 /* check first point to determine origin */ 2151 if ( tag == FT_CURVE_TAG_CONIC ) 2152 { 2153 /* First point is conic control. Yes, this happens. */ 2154 if ( FT_CURVE_TAG( outline->tags[last] ) == FT_CURVE_TAG_ON ) 2155 { 2156 /* start at last point if it is on the curve */ 2157 v_start = v_last; 2158 limit--; 2159 } 2160 else 2161 { 2162 /* if both first and last points are conic, */ 2163 /* start at their middle */ 2164 v_start.x = ( v_start.x + v_last.x ) / 2; 2165 v_start.y = ( v_start.y + v_last.y ) / 2; 2166 } 2167 point--; 2168 tags--; 2169 } 2170 2171 error = FT_Stroker_BeginSubPath( stroker, &v_start, opened ); 2172 if ( error ) 2173 goto Exit; 2174 2175 while ( point < limit ) 2176 { 2177 point++; 2178 tags++; 2179 2180 tag = FT_CURVE_TAG( tags[0] ); 2181 switch ( tag ) 2182 { 2183 case FT_CURVE_TAG_ON: /* emit a single line_to */ 2184 { 2185 FT_Vector vec; 2186 2187 2188 vec.x = point->x; 2189 vec.y = point->y; 2190 2191 error = FT_Stroker_LineTo( stroker, &vec ); 2192 if ( error ) 2193 goto Exit; 2194 continue; 2195 } 2196 2197 case FT_CURVE_TAG_CONIC: /* consume conic arcs */ 2198 v_control.x = point->x; 2199 v_control.y = point->y; 2200 2201 Do_Conic: 2202 if ( point < limit ) 2203 { 2204 FT_Vector vec; 2205 FT_Vector v_middle; 2206 2207 2208 point++; 2209 tags++; 2210 tag = FT_CURVE_TAG( tags[0] ); 2211 2212 vec = point[0]; 2213 2214 if ( tag == FT_CURVE_TAG_ON ) 2215 { 2216 error = FT_Stroker_ConicTo( stroker, &v_control, &vec ); 2217 if ( error ) 2218 goto Exit; 2219 continue; 2220 } 2221 2222 if ( tag != FT_CURVE_TAG_CONIC ) 2223 goto Invalid_Outline; 2224 2225 v_middle.x = ( v_control.x + vec.x ) / 2; 2226 v_middle.y = ( v_control.y + vec.y ) / 2; 2227 2228 error = FT_Stroker_ConicTo( stroker, &v_control, &v_middle ); 2229 if ( error ) 2230 goto Exit; 2231 2232 v_control = vec; 2233 goto Do_Conic; 2234 } 2235 2236 error = FT_Stroker_ConicTo( stroker, &v_control, &v_start ); 2237 goto Close; 2238 2239 default: /* FT_CURVE_TAG_CUBIC */ 2240 { 2241 FT_Vector vec1, vec2; 2242 2243 2244 if ( point + 1 > limit || 2245 FT_CURVE_TAG( tags[1] ) != FT_CURVE_TAG_CUBIC ) 2246 goto Invalid_Outline; 2247 2248 point += 2; 2249 tags += 2; 2250 2251 vec1 = point[-2]; 2252 vec2 = point[-1]; 2253 2254 if ( point <= limit ) 2255 { 2256 FT_Vector vec; 2257 2258 2259 vec = point[0]; 2260 2261 error = FT_Stroker_CubicTo( stroker, &vec1, &vec2, &vec ); 2262 if ( error ) 2263 goto Exit; 2264 continue; 2265 } 2266 2267 error = FT_Stroker_CubicTo( stroker, &vec1, &vec2, &v_start ); 2268 goto Close; 2269 } 2270 } 2271 } 2272 2273 Close: 2274 if ( error ) 2275 goto Exit; 2276 2277 /* don't try to end the path if no segments have been generated */ 2278 if ( !stroker->first_point ) 2279 { 2280 error = FT_Stroker_EndSubPath( stroker ); 2281 if ( error ) 2282 goto Exit; 2283 } 2284 2285 first = last + 1; 2286 } 2287 2288 return FT_Err_Ok; 2289 2290 Exit: 2291 return error; 2292 2293 Invalid_Outline: 2294 return FT_THROW( Invalid_Outline ); 2295 } 2296 2297 2298 /* documentation is in ftstroke.h */ 2299 2300 FT_EXPORT_DEF( FT_Error ) FT_Glyph_Stroke(FT_Glyph * pglyph,FT_Stroker stroker,FT_Bool destroy)2301 FT_Glyph_Stroke( FT_Glyph *pglyph, 2302 FT_Stroker stroker, 2303 FT_Bool destroy ) 2304 { 2305 FT_Error error = FT_ERR( Invalid_Argument ); 2306 FT_Glyph glyph = NULL; 2307 2308 /* for FT_OUTLINE_GLYPH_CLASS_GET (in PIC mode) */ 2309 FT_Library library = stroker->library; 2310 2311 FT_UNUSED( library ); 2312 2313 2314 if ( !pglyph ) 2315 goto Exit; 2316 2317 glyph = *pglyph; 2318 if ( !glyph || glyph->clazz != FT_OUTLINE_GLYPH_CLASS_GET ) 2319 goto Exit; 2320 2321 { 2322 FT_Glyph copy; 2323 2324 2325 error = FT_Glyph_Copy( glyph, © ); 2326 if ( error ) 2327 goto Exit; 2328 2329 glyph = copy; 2330 } 2331 2332 { 2333 FT_OutlineGlyph oglyph = (FT_OutlineGlyph)glyph; 2334 FT_Outline* outline = &oglyph->outline; 2335 FT_UInt num_points, num_contours; 2336 2337 2338 error = FT_Stroker_ParseOutline( stroker, outline, FALSE ); 2339 if ( error ) 2340 goto Fail; 2341 2342 FT_Stroker_GetCounts( stroker, &num_points, &num_contours ); 2343 2344 FT_Outline_Done( glyph->library, outline ); 2345 2346 error = FT_Outline_New( glyph->library, 2347 num_points, 2348 (FT_Int)num_contours, 2349 outline ); 2350 if ( error ) 2351 goto Fail; 2352 2353 outline->n_points = 0; 2354 outline->n_contours = 0; 2355 2356 FT_Stroker_Export( stroker, outline ); 2357 } 2358 2359 if ( destroy ) 2360 FT_Done_Glyph( *pglyph ); 2361 2362 *pglyph = glyph; 2363 goto Exit; 2364 2365 Fail: 2366 FT_Done_Glyph( glyph ); 2367 glyph = NULL; 2368 2369 if ( !destroy ) 2370 *pglyph = NULL; 2371 2372 Exit: 2373 return error; 2374 } 2375 2376 2377 /* documentation is in ftstroke.h */ 2378 2379 FT_EXPORT_DEF( FT_Error ) FT_Glyph_StrokeBorder(FT_Glyph * pglyph,FT_Stroker stroker,FT_Bool inside,FT_Bool destroy)2380 FT_Glyph_StrokeBorder( FT_Glyph *pglyph, 2381 FT_Stroker stroker, 2382 FT_Bool inside, 2383 FT_Bool destroy ) 2384 { 2385 FT_Error error = FT_ERR( Invalid_Argument ); 2386 FT_Glyph glyph = NULL; 2387 2388 /* for FT_OUTLINE_GLYPH_CLASS_GET (in PIC mode) */ 2389 FT_Library library = stroker->library; 2390 2391 FT_UNUSED( library ); 2392 2393 2394 if ( !pglyph ) 2395 goto Exit; 2396 2397 glyph = *pglyph; 2398 if ( !glyph || glyph->clazz != FT_OUTLINE_GLYPH_CLASS_GET ) 2399 goto Exit; 2400 2401 { 2402 FT_Glyph copy; 2403 2404 2405 error = FT_Glyph_Copy( glyph, © ); 2406 if ( error ) 2407 goto Exit; 2408 2409 glyph = copy; 2410 } 2411 2412 { 2413 FT_OutlineGlyph oglyph = (FT_OutlineGlyph)glyph; 2414 FT_StrokerBorder border; 2415 FT_Outline* outline = &oglyph->outline; 2416 FT_UInt num_points, num_contours; 2417 2418 2419 border = FT_Outline_GetOutsideBorder( outline ); 2420 if ( inside ) 2421 { 2422 if ( border == FT_STROKER_BORDER_LEFT ) 2423 border = FT_STROKER_BORDER_RIGHT; 2424 else 2425 border = FT_STROKER_BORDER_LEFT; 2426 } 2427 2428 error = FT_Stroker_ParseOutline( stroker, outline, FALSE ); 2429 if ( error ) 2430 goto Fail; 2431 2432 FT_Stroker_GetBorderCounts( stroker, border, 2433 &num_points, &num_contours ); 2434 2435 FT_Outline_Done( glyph->library, outline ); 2436 2437 error = FT_Outline_New( glyph->library, 2438 num_points, 2439 (FT_Int)num_contours, 2440 outline ); 2441 if ( error ) 2442 goto Fail; 2443 2444 outline->n_points = 0; 2445 outline->n_contours = 0; 2446 2447 FT_Stroker_ExportBorder( stroker, border, outline ); 2448 } 2449 2450 if ( destroy ) 2451 FT_Done_Glyph( *pglyph ); 2452 2453 *pglyph = glyph; 2454 goto Exit; 2455 2456 Fail: 2457 FT_Done_Glyph( glyph ); 2458 glyph = NULL; 2459 2460 if ( !destroy ) 2461 *pglyph = NULL; 2462 2463 Exit: 2464 return error; 2465 } 2466 2467 2468 /* END */ 2469