1 2<!doctype html> 3<html lang="en" class="no-js"> 4 <head> 5 6 <meta charset="utf-8"> 7 <meta name="viewport" content="width=device-width,initial-scale=1"> 8 9 <meta name="description" content="API Reference Documentation for FreeType-2.12.1"> 10 11 12 13 <meta name="author" content="FreeType Contributors"> 14 15 16 <link rel="icon" href="images/favico.ico"> 17 <meta name="generator" content="mkdocs-1.2.1, mkdocs-material-7.1.9"> 18 19 20 21 <title>Scanline Converter - FreeType-2.12.1 API Reference</title> 22 23 24 25 <link rel="stylesheet" href="assets/stylesheets/main.ca7ac06f.min.css"> 26 27 28 <link rel="stylesheet" href="assets/stylesheets/palette.f1a3b89f.min.css"> 29 30 31 32 <meta name="theme-color" content="#4cae4f"> 33 34 35 36 37 38 39 40 <link rel="preconnect" href="https://fonts.gstatic.com" crossorigin> 41 <link rel="stylesheet" href="https://fonts.googleapis.com/css?family=Noto+Serif:300,400,400i,700%7CRoboto+Mono&display=fallback"> 42 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class="md-header__inner md-grid" aria-label="Header"> 85 <a href="index.html" title="FreeType-2.12.1 API Reference" class="md-header__button md-logo" aria-label="FreeType-2.12.1 API Reference" data-md-component="logo"> 86 87 <img src="images/favico.ico" alt="logo"> 88 89 </a> 90 <label class="md-header__button md-icon" for="__drawer"> 91 <svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24"><path d="M3 6h18v2H3V6m0 5h18v2H3v-2m0 5h18v2H3v-2z"/></svg> 92 </label> 93 <div class="md-header__title" data-md-component="header-title"> 94 <div class="md-header__ellipsis"> 95 <div class="md-header__topic"> 96 <span class="md-ellipsis"> 97 FreeType-2.12.1 API Reference 98 </span> 99 </div> 100 <div class="md-header__topic" data-md-component="header-topic"> 101 <span class="md-ellipsis"> 102 103 Scanline Converter 104 105 </span> 106 </div> 107 </div> 108 </div> 109 110 111 112 <label class="md-header__button md-icon" for="__search"> 113 <svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24"><path d="M9.5 3A6.5 6.5 0 0 1 16 9.5c0 1.61-.59 3.09-1.56 4.23l.27.27h.79l5 5-1.5 1.5-5-5v-.79l-.27-.27A6.516 6.516 0 0 1 9.5 16 6.5 6.5 0 0 1 3 9.5 6.5 6.5 0 0 1 9.5 3m0 2C7 5 5 7 5 9.5S7 14 9.5 14 14 12 14 9.5 12 5 9.5 5z"/></svg> 114 </label> 115 116<div class="md-search" data-md-component="search" role="dialog"> 117 <label class="md-search__overlay" for="__search"></label> 118 <div class="md-search__inner" role="search"> 119 <form class="md-search__form" name="search"> 120 <input type="text" class="md-search__input" name="query" aria-label="Search" placeholder="Search" autocapitalize="off" autocorrect="off" autocomplete="off" spellcheck="false" data-md-component="search-query" data-md-state="active" required> 121 <label class="md-search__icon md-icon" for="__search"> 122 <svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24"><path d="M9.5 3A6.5 6.5 0 0 1 16 9.5c0 1.61-.59 3.09-1.56 4.23l.27.27h.79l5 5-1.5 1.5-5-5v-.79l-.27-.27A6.516 6.516 0 0 1 9.5 16 6.5 6.5 0 0 1 3 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149 150 151 <main class="md-main" data-md-component="main"> 152 <div class="md-main__inner md-grid"> 153 154 155 156 <div class="md-sidebar md-sidebar--primary" data-md-component="sidebar" data-md-type="navigation" > 157 <div class="md-sidebar__scrollwrap"> 158 <div class="md-sidebar__inner"> 159 160 161 162<nav class="md-nav md-nav--primary" aria-label="Navigation" data-md-level="0"> 163 <label class="md-nav__title" for="__drawer"> 164 <a href="index.html" title="FreeType-2.12.1 API Reference" class="md-nav__button md-logo" aria-label="FreeType-2.12.1 API Reference" data-md-component="logo"> 165 166 <img src="images/favico.ico" alt="logo"> 167 168 </a> 169 FreeType-2.12.1 API Reference 170 </label> 171 172 <ul class="md-nav__list" data-md-scrollfix> 173 174 175 176 177 178 179 180 181 <li class="md-nav__item"> 182 <a href="index.html" class="md-nav__link"> 183 TOC 184 </a> 185 </li> 186 187 188 189 190 191 192 193 194 195 196 <li class="md-nav__item"> 197 <a href="ft2-index.html" class="md-nav__link"> 198 Index 199 </a> 200 </li> 201 202 203 204 205 206 207 208 209 210 211 212 <li class="md-nav__item md-nav__item--nested"> 213 214 215 <input class="md-nav__toggle md-toggle" data-md-toggle="__nav_3" type="checkbox" id="__nav_3" > 216 217 <label class="md-nav__link" for="__nav_3"> 218 General Remarks 219 <span class="md-nav__icon md-icon"></span> 220 </label> 221 <nav class="md-nav" aria-label="General Remarks" data-md-level="1"> 222 <label class="md-nav__title" for="__nav_3"> 223 <span class="md-nav__icon md-icon"></span> 224 General Remarks 225 </label> 226 <ul class="md-nav__list" data-md-scrollfix> 227 228 229 230 231 232 <li class="md-nav__item"> 233 <a href="ft2-preamble.html" class="md-nav__link"> 234 Preamble 235 </a> 236 </li> 237 238 239 240 241 242 243 244 <li class="md-nav__item"> 245 <a href="ft2-header_inclusion.html" class="md-nav__link"> 246 FreeType's header inclusion scheme 247 </a> 248 </li> 249 250 251 252 253 254 255 256 <li class="md-nav__item"> 257 <a href="ft2-user_allocation.html" class="md-nav__link"> 258 User allocation 259 </a> 260 </li> 261 262 263 264 </ul> 265 </nav> 266 </li> 267 268 269 270 271 272 273 274 275 276 277 278 <li class="md-nav__item md-nav__item--nested"> 279 280 281 <input class="md-nav__toggle md-toggle" data-md-toggle="__nav_4" type="checkbox" id="__nav_4" > 282 283 <label class="md-nav__link" for="__nav_4"> 284 Core API 285 <span class="md-nav__icon md-icon"></span> 286 </label> 287 <nav class="md-nav" aria-label="Core API" data-md-level="1"> 288 <label class="md-nav__title" for="__nav_4"> 289 <span class="md-nav__icon md-icon"></span> 290 Core API 291 </label> 292 <ul class="md-nav__list" data-md-scrollfix> 293 294 295 296 297 298 <li class="md-nav__item"> 299 <a href="ft2-version.html" class="md-nav__link"> 300 FreeType Version 301 </a> 302 </li> 303 304 305 306 307 308 309 310 <li class="md-nav__item"> 311 <a href="ft2-basic_types.html" class="md-nav__link"> 312 Basic Data Types 313 </a> 314 </li> 315 316 317 318 319 320 321 322 <li class="md-nav__item"> 323 <a href="ft2-base_interface.html" class="md-nav__link"> 324 Base Interface 325 </a> 326 </li> 327 328 329 330 331 332 333 334 <li class="md-nav__item"> 335 <a href="ft2-glyph_variants.html" class="md-nav__link"> 336 Unicode Variation Sequences 337 </a> 338 </li> 339 340 341 342 343 344 345 346 <li class="md-nav__item"> 347 <a href="ft2-color_management.html" class="md-nav__link"> 348 Glyph Color Management 349 </a> 350 </li> 351 352 353 354 355 356 357 358 <li class="md-nav__item"> 359 <a href="ft2-layer_management.html" class="md-nav__link"> 360 Glyph Layer Management 361 </a> 362 </li> 363 364 365 366 367 368 369 370 <li class="md-nav__item"> 371 <a href="ft2-glyph_management.html" class="md-nav__link"> 372 Glyph Management 373 </a> 374 </li> 375 376 377 378 379 380 381 382 <li class="md-nav__item"> 383 <a href="ft2-mac_specific.html" class="md-nav__link"> 384 Mac Specific Interface 385 </a> 386 </li> 387 388 389 390 391 392 393 394 <li class="md-nav__item"> 395 <a href="ft2-sizes_management.html" class="md-nav__link"> 396 Size Management 397 </a> 398 </li> 399 400 401 402 403 404 405 406 <li class="md-nav__item"> 407 <a href="ft2-header_file_macros.html" class="md-nav__link"> 408 Header File Macros 409 </a> 410 </li> 411 412 413 414 </ul> 415 </nav> 416 </li> 417 418 419 420 421 422 423 424 425 426 427 428 <li class="md-nav__item md-nav__item--nested"> 429 430 431 <input class="md-nav__toggle md-toggle" data-md-toggle="__nav_5" type="checkbox" id="__nav_5" > 432 433 <label class="md-nav__link" for="__nav_5"> 434 Format-Specific API 435 <span class="md-nav__icon md-icon"></span> 436 </label> 437 <nav class="md-nav" aria-label="Format-Specific API" data-md-level="1"> 438 <label class="md-nav__title" for="__nav_5"> 439 <span class="md-nav__icon md-icon"></span> 440 Format-Specific API 441 </label> 442 <ul class="md-nav__list" data-md-scrollfix> 443 444 445 446 447 448 <li class="md-nav__item"> 449 <a href="ft2-multiple_masters.html" class="md-nav__link"> 450 Multiple Masters 451 </a> 452 </li> 453 454 455 456 457 458 459 460 <li class="md-nav__item"> 461 <a href="ft2-truetype_tables.html" class="md-nav__link"> 462 TrueType Tables 463 </a> 464 </li> 465 466 467 468 469 470 471 472 <li class="md-nav__item"> 473 <a href="ft2-type1_tables.html" class="md-nav__link"> 474 Type 1 Tables 475 </a> 476 </li> 477 478 479 480 481 482 483 484 <li class="md-nav__item"> 485 <a href="ft2-sfnt_names.html" class="md-nav__link"> 486 SFNT Names 487 </a> 488 </li> 489 490 491 492 493 494 495 496 <li class="md-nav__item"> 497 <a href="ft2-bdf_fonts.html" class="md-nav__link"> 498 BDF and PCF Files 499 </a> 500 </li> 501 502 503 504 505 506 507 508 <li class="md-nav__item"> 509 <a href="ft2-cid_fonts.html" class="md-nav__link"> 510 CID Fonts 511 </a> 512 </li> 513 514 515 516 517 518 519 520 <li class="md-nav__item"> 521 <a href="ft2-pfr_fonts.html" class="md-nav__link"> 522 PFR Fonts 523 </a> 524 </li> 525 526 527 528 529 530 531 532 <li class="md-nav__item"> 533 <a href="ft2-winfnt_fonts.html" class="md-nav__link"> 534 Window FNT Files 535 </a> 536 </li> 537 538 539 540 541 542 543 544 <li class="md-nav__item"> 545 <a href="ft2-svg_fonts.html" class="md-nav__link"> 546 OpenType SVG Fonts 547 </a> 548 </li> 549 550 551 552 553 554 555 556 <li class="md-nav__item"> 557 <a href="ft2-font_formats.html" class="md-nav__link"> 558 Font Formats 559 </a> 560 </li> 561 562 563 564 565 566 567 568 <li class="md-nav__item"> 569 <a href="ft2-gasp_table.html" class="md-nav__link"> 570 Gasp Table 571 </a> 572 </li> 573 574 575 576 </ul> 577 </nav> 578 </li> 579 580 581 582 583 584 585 586 587 588 589 590 <li class="md-nav__item md-nav__item--nested"> 591 592 593 <input class="md-nav__toggle md-toggle" data-md-toggle="__nav_6" type="checkbox" id="__nav_6" > 594 595 <label class="md-nav__link" for="__nav_6"> 596 Controlling FreeType Modules 597 <span class="md-nav__icon md-icon"></span> 598 </label> 599 <nav class="md-nav" aria-label="Controlling FreeType Modules" data-md-level="1"> 600 <label class="md-nav__title" for="__nav_6"> 601 <span class="md-nav__icon md-icon"></span> 602 Controlling FreeType Modules 603 </label> 604 <ul class="md-nav__list" data-md-scrollfix> 605 606 607 608 609 610 <li class="md-nav__item"> 611 <a href="ft2-auto_hinter.html" class="md-nav__link"> 612 The auto-hinter 613 </a> 614 </li> 615 616 617 618 619 620 621 622 <li class="md-nav__item"> 623 <a href="ft2-cff_driver.html" class="md-nav__link"> 624 The CFF driver 625 </a> 626 </li> 627 628 629 630 631 632 633 634 <li class="md-nav__item"> 635 <a href="ft2-t1_cid_driver.html" class="md-nav__link"> 636 The Type 1 and CID drivers 637 </a> 638 </li> 639 640 641 642 643 644 645 646 <li class="md-nav__item"> 647 <a href="ft2-tt_driver.html" class="md-nav__link"> 648 The TrueType driver 649 </a> 650 </li> 651 652 653 654 655 656 657 658 <li class="md-nav__item"> 659 <a href="ft2-pcf_driver.html" class="md-nav__link"> 660 The PCF driver 661 </a> 662 </li> 663 664 665 666 667 668 669 670 <li class="md-nav__item"> 671 <a href="ft2-ot_svg_driver.html" class="md-nav__link"> 672 The SVG driver 673 </a> 674 </li> 675 676 677 678 679 680 681 682 <li class="md-nav__item"> 683 <a href="ft2-properties.html" class="md-nav__link"> 684 Driver properties 685 </a> 686 </li> 687 688 689 690 691 692 693 694 <li class="md-nav__item"> 695 <a href="ft2-parameter_tags.html" class="md-nav__link"> 696 Parameter Tags 697 </a> 698 </li> 699 700 701 702 703 704 705 706 <li class="md-nav__item"> 707 <a href="ft2-lcd_rendering.html" class="md-nav__link"> 708 Subpixel Rendering 709 </a> 710 </li> 711 712 713 714 </ul> 715 </nav> 716 </li> 717 718 719 720 721 722 723 724 725 726 727 728 <li class="md-nav__item md-nav__item--nested"> 729 730 731 <input class="md-nav__toggle md-toggle" data-md-toggle="__nav_7" type="checkbox" id="__nav_7" > 732 733 <label class="md-nav__link" for="__nav_7"> 734 Cache Sub-System 735 <span class="md-nav__icon md-icon"></span> 736 </label> 737 <nav class="md-nav" aria-label="Cache Sub-System" data-md-level="1"> 738 <label class="md-nav__title" for="__nav_7"> 739 <span class="md-nav__icon md-icon"></span> 740 Cache Sub-System 741 </label> 742 <ul class="md-nav__list" data-md-scrollfix> 743 744 745 746 747 748 <li class="md-nav__item"> 749 <a href="ft2-cache_subsystem.html" class="md-nav__link"> 750 Cache Sub-System 751 </a> 752 </li> 753 754 755 756 </ul> 757 </nav> 758 </li> 759 760 761 762 763 764 765 766 767 768 769 770 771 772 <li class="md-nav__item md-nav__item--active md-nav__item--nested"> 773 774 775 <input class="md-nav__toggle md-toggle" data-md-toggle="__nav_8" type="checkbox" id="__nav_8" checked> 776 777 <label class="md-nav__link" for="__nav_8"> 778 Support API 779 <span class="md-nav__icon md-icon"></span> 780 </label> 781 <nav class="md-nav" aria-label="Support API" data-md-level="1"> 782 <label class="md-nav__title" for="__nav_8"> 783 <span class="md-nav__icon md-icon"></span> 784 Support API 785 </label> 786 <ul class="md-nav__list" data-md-scrollfix> 787 788 789 790 791 792 <li class="md-nav__item"> 793 <a href="ft2-computations.html" class="md-nav__link"> 794 Computations 795 </a> 796 </li> 797 798 799 800 801 802 803 804 <li class="md-nav__item"> 805 <a href="ft2-list_processing.html" class="md-nav__link"> 806 List Processing 807 </a> 808 </li> 809 810 811 812 813 814 815 816 <li class="md-nav__item"> 817 <a href="ft2-outline_processing.html" class="md-nav__link"> 818 Outline Processing 819 </a> 820 </li> 821 822 823 824 825 826 827 828 <li class="md-nav__item"> 829 <a href="ft2-quick_advance.html" class="md-nav__link"> 830 Quick retrieval of advance values 831 </a> 832 </li> 833 834 835 836 837 838 839 840 <li class="md-nav__item"> 841 <a href="ft2-bitmap_handling.html" class="md-nav__link"> 842 Bitmap Handling 843 </a> 844 </li> 845 846 847 848 849 850 851 852 853 854 <li class="md-nav__item md-nav__item--active"> 855 856 <input class="md-nav__toggle md-toggle" data-md-toggle="toc" type="checkbox" id="__toc"> 857 858 859 860 861 862 <label class="md-nav__link md-nav__link--active" for="__toc"> 863 Scanline Converter 864 <span class="md-nav__icon md-icon"></span> 865 </label> 866 867 <a href="ft2-raster.html" class="md-nav__link md-nav__link--active"> 868 Scanline Converter 869 </a> 870 871 872<nav class="md-nav md-nav--secondary" aria-label="Table of contents"> 873 874 875 876 877 878 879 <label class="md-nav__title" for="__toc"> 880 <span class="md-nav__icon md-icon"></span> 881 Table of contents 882 </label> 883 <ul class="md-nav__list" data-md-component="toc" data-md-scrollfix> 884 885 <li class="md-nav__item"> 886 <a href="#synopsis" class="md-nav__link"> 887 Synopsis 888 </a> 889 890</li> 891 892 <li class="md-nav__item"> 893 <a href="#ft_span" class="md-nav__link"> 894 FT_Span 895 </a> 896 897</li> 898 899 <li class="md-nav__item"> 900 <a href="#ft_spanfunc" class="md-nav__link"> 901 FT_SpanFunc 902 </a> 903 904</li> 905 906 <li class="md-nav__item"> 907 <a href="#ft_raster_params" class="md-nav__link"> 908 FT_Raster_Params 909 </a> 910 911</li> 912 913 <li class="md-nav__item"> 914 <a href="#ft_raster_flag_xxx" class="md-nav__link"> 915 FT_RASTER_FLAG_XXX 916 </a> 917 918</li> 919 920 <li class="md-nav__item"> 921 <a href="#ft_raster" class="md-nav__link"> 922 FT_Raster 923 </a> 924 925</li> 926 927 <li class="md-nav__item"> 928 <a href="#ft_raster_newfunc" class="md-nav__link"> 929 FT_Raster_NewFunc 930 </a> 931 932</li> 933 934 <li class="md-nav__item"> 935 <a href="#ft_raster_donefunc" class="md-nav__link"> 936 FT_Raster_DoneFunc 937 </a> 938 939</li> 940 941 <li class="md-nav__item"> 942 <a href="#ft_raster_resetfunc" class="md-nav__link"> 943 FT_Raster_ResetFunc 944 </a> 945 946</li> 947 948 <li class="md-nav__item"> 949 <a href="#ft_raster_setmodefunc" class="md-nav__link"> 950 FT_Raster_SetModeFunc 951 </a> 952 953</li> 954 955 <li class="md-nav__item"> 956 <a href="#ft_raster_renderfunc" class="md-nav__link"> 957 FT_Raster_RenderFunc 958 </a> 959 960</li> 961 962 <li class="md-nav__item"> 963 <a href="#ft_raster_funcs" class="md-nav__link"> 964 FT_Raster_Funcs 965 </a> 966 967</li> 968 969 <li class="md-nav__item"> 970 <a href="#ft_raster_bittest_func" class="md-nav__link"> 971 FT_Raster_BitTest_Func 972 </a> 973 974</li> 975 976 <li class="md-nav__item"> 977 <a href="#ft_raster_bitset_func" class="md-nav__link"> 978 FT_Raster_BitSet_Func 979 </a> 980 981</li> 982 983 </ul> 984 985</nav> 986 987 </li> 988 989 990 991 992 993 994 995 <li class="md-nav__item"> 996 <a href="ft2-glyph_stroker.html" class="md-nav__link"> 997 Glyph Stroker 998 </a> 999 </li> 1000 1001 1002 1003 1004 1005 1006 1007 <li class="md-nav__item"> 1008 <a href="ft2-system_interface.html" class="md-nav__link"> 1009 System Interface 1010 </a> 1011 </li> 1012 1013 1014 1015 1016 1017 1018 1019 <li class="md-nav__item"> 1020 <a href="ft2-module_management.html" class="md-nav__link"> 1021 Module Management 1022 </a> 1023 </li> 1024 1025 1026 1027 1028 1029 1030 1031 <li class="md-nav__item"> 1032 <a href="ft2-gzip.html" class="md-nav__link"> 1033 GZIP Streams 1034 </a> 1035 </li> 1036 1037 1038 1039 1040 1041 1042 1043 <li class="md-nav__item"> 1044 <a href="ft2-lzw.html" class="md-nav__link"> 1045 LZW Streams 1046 </a> 1047 </li> 1048 1049 1050 1051 1052 1053 1054 1055 <li class="md-nav__item"> 1056 <a href="ft2-bzip2.html" class="md-nav__link"> 1057 BZIP2 Streams 1058 </a> 1059 </li> 1060 1061 1062 1063 1064 1065 1066 1067 <li class="md-nav__item"> 1068 <a href="ft2-debugging_apis.html" class="md-nav__link"> 1069 External Debugging APIs 1070 </a> 1071 </li> 1072 1073 1074 1075 </ul> 1076 </nav> 1077 </li> 1078 1079 1080 1081 1082 1083 1084 1085 1086 1087 1088 1089 <li class="md-nav__item md-nav__item--nested"> 1090 1091 1092 <input class="md-nav__toggle md-toggle" data-md-toggle="__nav_9" type="checkbox" id="__nav_9" > 1093 1094 <label class="md-nav__link" for="__nav_9"> 1095 Error Codes 1096 <span class="md-nav__icon md-icon"></span> 1097 </label> 1098 <nav class="md-nav" aria-label="Error Codes" data-md-level="1"> 1099 <label class="md-nav__title" for="__nav_9"> 1100 <span class="md-nav__icon md-icon"></span> 1101 Error Codes 1102 </label> 1103 <ul class="md-nav__list" data-md-scrollfix> 1104 1105 1106 1107 1108 1109 <li class="md-nav__item"> 1110 <a href="ft2-error_enumerations.html" class="md-nav__link"> 1111 Error Enumerations 1112 </a> 1113 </li> 1114 1115 1116 1117 1118 1119 1120 1121 <li class="md-nav__item"> 1122 <a href="ft2-error_code_values.html" class="md-nav__link"> 1123 Error Code Values 1124 </a> 1125 </li> 1126 1127 1128 1129 </ul> 1130 </nav> 1131 </li> 1132 1133 1134 1135 1136 1137 1138 1139 1140 1141 1142 1143 <li class="md-nav__item md-nav__item--nested"> 1144 1145 1146 <input class="md-nav__toggle md-toggle" data-md-toggle="__nav_10" type="checkbox" id="__nav_10" > 1147 1148 <label class="md-nav__link" for="__nav_10"> 1149 Miscellaneous 1150 <span class="md-nav__icon md-icon"></span> 1151 </label> 1152 <nav class="md-nav" aria-label="Miscellaneous" data-md-level="1"> 1153 <label class="md-nav__title" for="__nav_10"> 1154 <span class="md-nav__icon md-icon"></span> 1155 Miscellaneous 1156 </label> 1157 <ul class="md-nav__list" data-md-scrollfix> 1158 1159 1160 1161 1162 1163 <li class="md-nav__item"> 1164 <a href="ft2-gx_validation.html" class="md-nav__link"> 1165 TrueTypeGX/AAT Validation 1166 </a> 1167 </li> 1168 1169 1170 1171 1172 1173 1174 1175 <li class="md-nav__item"> 1176 <a href="ft2-incremental.html" class="md-nav__link"> 1177 Incremental Loading 1178 </a> 1179 </li> 1180 1181 1182 1183 1184 1185 1186 1187 <li class="md-nav__item"> 1188 <a href="ft2-truetype_engine.html" class="md-nav__link"> 1189 The TrueType Engine 1190 </a> 1191 </li> 1192 1193 1194 1195 1196 1197 1198 1199 <li class="md-nav__item"> 1200 <a href="ft2-ot_validation.html" class="md-nav__link"> 1201 OpenType Validation 1202 </a> 1203 </li> 1204 1205 1206 1207 </ul> 1208 </nav> 1209 </li> 1210 1211 1212 1213 </ul> 1214</nav> 1215 </div> 1216 </div> 1217 </div> 1218 1219 1220 1221 <div class="md-sidebar md-sidebar--secondary" data-md-component="sidebar" data-md-type="toc" > 1222 <div class="md-sidebar__scrollwrap"> 1223 <div class="md-sidebar__inner"> 1224 1225<nav class="md-nav md-nav--secondary" aria-label="Table of contents"> 1226 1227 1228 1229 1230 1231 1232 <label class="md-nav__title" for="__toc"> 1233 <span class="md-nav__icon md-icon"></span> 1234 Table of contents 1235 </label> 1236 <ul class="md-nav__list" data-md-component="toc" data-md-scrollfix> 1237 1238 <li class="md-nav__item"> 1239 <a href="#synopsis" class="md-nav__link"> 1240 Synopsis 1241 </a> 1242 1243</li> 1244 1245 <li class="md-nav__item"> 1246 <a href="#ft_span" class="md-nav__link"> 1247 FT_Span 1248 </a> 1249 1250</li> 1251 1252 <li class="md-nav__item"> 1253 <a href="#ft_spanfunc" class="md-nav__link"> 1254 FT_SpanFunc 1255 </a> 1256 1257</li> 1258 1259 <li class="md-nav__item"> 1260 <a href="#ft_raster_params" class="md-nav__link"> 1261 FT_Raster_Params 1262 </a> 1263 1264</li> 1265 1266 <li class="md-nav__item"> 1267 <a href="#ft_raster_flag_xxx" class="md-nav__link"> 1268 FT_RASTER_FLAG_XXX 1269 </a> 1270 1271</li> 1272 1273 <li class="md-nav__item"> 1274 <a href="#ft_raster" class="md-nav__link"> 1275 FT_Raster 1276 </a> 1277 1278</li> 1279 1280 <li class="md-nav__item"> 1281 <a href="#ft_raster_newfunc" class="md-nav__link"> 1282 FT_Raster_NewFunc 1283 </a> 1284 1285</li> 1286 1287 <li class="md-nav__item"> 1288 <a href="#ft_raster_donefunc" class="md-nav__link"> 1289 FT_Raster_DoneFunc 1290 </a> 1291 1292</li> 1293 1294 <li class="md-nav__item"> 1295 <a href="#ft_raster_resetfunc" class="md-nav__link"> 1296 FT_Raster_ResetFunc 1297 </a> 1298 1299</li> 1300 1301 <li class="md-nav__item"> 1302 <a href="#ft_raster_setmodefunc" class="md-nav__link"> 1303 FT_Raster_SetModeFunc 1304 </a> 1305 1306</li> 1307 1308 <li class="md-nav__item"> 1309 <a href="#ft_raster_renderfunc" class="md-nav__link"> 1310 FT_Raster_RenderFunc 1311 </a> 1312 1313</li> 1314 1315 <li class="md-nav__item"> 1316 <a href="#ft_raster_funcs" class="md-nav__link"> 1317 FT_Raster_Funcs 1318 </a> 1319 1320</li> 1321 1322 <li class="md-nav__item"> 1323 <a href="#ft_raster_bittest_func" class="md-nav__link"> 1324 FT_Raster_BitTest_Func 1325 </a> 1326 1327</li> 1328 1329 <li class="md-nav__item"> 1330 <a href="#ft_raster_bitset_func" class="md-nav__link"> 1331 FT_Raster_BitSet_Func 1332 </a> 1333 1334</li> 1335 1336 </ul> 1337 1338</nav> 1339 </div> 1340 </div> 1341 </div> 1342 1343 1344 <div class="md-content" data-md-component="content"> 1345 <article class="md-content__inner md-typeset"> 1346 1347 1348 1349 <p><a href="https://www.freetype.org">FreeType</a> » <a href="../">Docs</a> » <a href="index.html#support-api">Support API</a> » Scanline Converter</p> 1350<hr /> 1351<h1 id="scanline-converter">Scanline Converter<a class="headerlink" href="#scanline-converter" title="Permanent link">¶</a></h1> 1352<h2 id="synopsis">Synopsis<a class="headerlink" href="#synopsis" title="Permanent link">¶</a></h2> 1353<p>A raster or a rasterizer is a scan converter in charge of producing a pixel coverage bitmap that can be used as an alpha channel when compositing a glyph with a background. FreeType comes with two rasterizers: bilevel <code>raster1</code> and anti-aliased <code>smooth</code> are two separate modules. They are usually called from the high-level <code><a href="ft2-base_interface.html#ft_load_glyph">FT_Load_Glyph</a></code> or <code><a href="ft2-base_interface.html#ft_render_glyph">FT_Render_Glyph</a></code> functions and produce the entire coverage bitmap at once, while staying largely invisible to users.</p> 1354<p>Instead of working with complete coverage bitmaps, it is also possible to intercept consecutive pixel runs on the same scanline with the same coverage, called <em>spans</em>, and process them individually. Only the <code>smooth</code> rasterizer permits this when calling <code><a href="ft2-outline_processing.html#ft_outline_render">FT_Outline_Render</a></code> with <code><a href="ft2-raster.html#ft_raster_params">FT_Raster_Params</a></code> as described below.</p> 1355<p>Working with either complete bitmaps or spans it is important to think of them as colorless coverage objects suitable as alpha channels to blend arbitrary colors with a background. For best results, it is recommended to use gamma correction, too.</p> 1356<p>This section also describes the public API needed to set up alternative <code><a href="ft2-module_management.html#ft_renderer">FT_Renderer</a></code> modules.</p> 1357<h2 id="ft_span">FT_Span<a class="headerlink" href="#ft_span" title="Permanent link">¶</a></h2> 1358<p>Defined in FT_IMAGE_H (freetype/ftimage.h).</p> 1359<div class = "codehilite"><pre><code> <span class="keyword">typedef</span> <span class="keyword">struct</span> FT_Span_ 1360 { 1361 <span class="keyword">short</span> x; 1362 <span class="keyword">unsigned</span> <span class="keyword">short</span> len; 1363 <span class="keyword">unsigned</span> <span class="keyword">char</span> coverage; 1364 1365 } <b>FT_Span</b>; 1366</code></pre></div> 1367 1368<p>A structure to model a single span of consecutive pixels when rendering an anti-aliased bitmap.</p> 1369<h4>fields</h4> 1370<table class="fields"> 1371<tr><td class="val" id="x">x</td><td class="desc"> 1372<p>The span's horizontal start position.</p> 1373</td></tr> 1374<tr><td class="val" id="len">len</td><td class="desc"> 1375<p>The span's length in pixels.</p> 1376</td></tr> 1377<tr><td class="val" id="coverage">coverage</td><td class="desc"> 1378<p>The span color/coverage, ranging from 0 (background) to 255 (foreground).</p> 1379</td></tr> 1380</table> 1381 1382<h4>note</h4> 1383 1384<p>This structure is used by the span drawing callback type named <code><a href="ft2-raster.html#ft_spanfunc">FT_SpanFunc</a></code> that takes the y coordinate of the span as a parameter.</p> 1385<p>The anti-aliased rasterizer produces coverage values from 0 to 255, this is, from completely transparent to completely opaque.</p> 1386<hr> 1387 1388<h2 id="ft_spanfunc">FT_SpanFunc<a class="headerlink" href="#ft_spanfunc" title="Permanent link">¶</a></h2> 1389<p>Defined in FT_IMAGE_H (freetype/ftimage.h).</p> 1390<div class = "codehilite"><pre><code> <span class="keyword">typedef</span> <span class="keyword">void</span> 1391 (*<b>FT_SpanFunc</b>)( <span class="keyword">int</span> y, 1392 <span class="keyword">int</span> count, 1393 <span class="keyword">const</span> <a href="ft2-raster.html#ft_span">FT_Span</a>* spans, 1394 <span class="keyword">void</span>* user ); 1395 1396#<span class="keyword">define</span> FT_Raster_Span_Func <b>FT_SpanFunc</b> 1397</code></pre></div> 1398 1399<p>A function used as a call-back by the anti-aliased renderer in order to let client applications draw themselves the pixel spans on each scan line.</p> 1400<h4>input</h4> 1401<table class="fields"> 1402<tr><td class="val" id="y">y</td><td class="desc"> 1403<p>The scanline's upward y coordinate.</p> 1404</td></tr> 1405<tr><td class="val" id="count">count</td><td class="desc"> 1406<p>The number of spans to draw on this scanline.</p> 1407</td></tr> 1408<tr><td class="val" id="spans">spans</td><td class="desc"> 1409<p>A table of <code>count</code> spans to draw on the scanline.</p> 1410</td></tr> 1411<tr><td class="val" id="user">user</td><td class="desc"> 1412<p>User-supplied data that is passed to the callback.</p> 1413</td></tr> 1414</table> 1415 1416<h4>note</h4> 1417 1418<p>This callback allows client applications to directly render the spans of the anti-aliased bitmap to any kind of surfaces.</p> 1419<p>This can be used to write anti-aliased outlines directly to a given background bitmap using alpha compositing. It can also be used for oversampling and averaging.</p> 1420<hr> 1421 1422<h2 id="ft_raster_params">FT_Raster_Params<a class="headerlink" href="#ft_raster_params" title="Permanent link">¶</a></h2> 1423<p>Defined in FT_IMAGE_H (freetype/ftimage.h).</p> 1424<div class = "codehilite"><pre><code> <span class="keyword">typedef</span> <span class="keyword">struct</span> FT_Raster_Params_ 1425 { 1426 <span class="keyword">const</span> <a href="ft2-basic_types.html#ft_bitmap">FT_Bitmap</a>* target; 1427 <span class="keyword">const</span> <span class="keyword">void</span>* source; 1428 <span class="keyword">int</span> flags; 1429 <a href="ft2-raster.html#ft_spanfunc">FT_SpanFunc</a> gray_spans; 1430 <a href="ft2-raster.html#ft_spanfunc">FT_SpanFunc</a> black_spans; /* unused */ 1431 <a href="ft2-raster.html#ft_raster_bittest_func">FT_Raster_BitTest_Func</a> bit_test; /* unused */ 1432 <a href="ft2-raster.html#ft_raster_bitset_func">FT_Raster_BitSet_Func</a> bit_set; /* unused */ 1433 <span class="keyword">void</span>* user; 1434 <a href="ft2-basic_types.html#ft_bbox">FT_BBox</a> clip_box; 1435 1436 } <b>FT_Raster_Params</b>; 1437</code></pre></div> 1438 1439<p>A structure to hold the parameters used by a raster's render function, passed as an argument to <code><a href="ft2-outline_processing.html#ft_outline_render">FT_Outline_Render</a></code>.</p> 1440<h4>fields</h4> 1441<table class="fields"> 1442<tr><td class="val" id="target">target</td><td class="desc"> 1443<p>The target bitmap.</p> 1444</td></tr> 1445<tr><td class="val" id="source">source</td><td class="desc"> 1446<p>A pointer to the source glyph image (e.g., an <code><a href="ft2-outline_processing.html#ft_outline">FT_Outline</a></code>).</p> 1447</td></tr> 1448<tr><td class="val" id="flags">flags</td><td class="desc"> 1449<p>The rendering flags.</p> 1450</td></tr> 1451<tr><td class="val" id="gray_spans">gray_spans</td><td class="desc"> 1452<p>The gray span drawing callback.</p> 1453</td></tr> 1454<tr><td class="val" id="black_spans">black_spans</td><td class="desc"> 1455<p>Unused.</p> 1456</td></tr> 1457<tr><td class="val" id="bit_test">bit_test</td><td class="desc"> 1458<p>Unused.</p> 1459</td></tr> 1460<tr><td class="val" id="bit_set">bit_set</td><td class="desc"> 1461<p>Unused.</p> 1462</td></tr> 1463<tr><td class="val" id="user">user</td><td class="desc"> 1464<p>User-supplied data that is passed to each drawing callback.</p> 1465</td></tr> 1466<tr><td class="val" id="clip_box">clip_box</td><td class="desc"> 1467<p>An optional span clipping box expressed in <em>integer</em> pixels (not in 26.6 fixed-point units).</p> 1468</td></tr> 1469</table> 1470 1471<h4>note</h4> 1472 1473<p>The <code><a href="ft2-raster.html#ft_raster_flag_xxx">FT_RASTER_FLAG_AA</a></code> bit flag must be set in the <code>flags</code> to generate an anti-aliased glyph bitmap, otherwise a monochrome bitmap is generated. The <code>target</code> should have appropriate pixel mode and its dimensions define the clipping region.</p> 1474<p>If both <code><a href="ft2-raster.html#ft_raster_flag_xxx">FT_RASTER_FLAG_AA</a></code> and <code><a href="ft2-raster.html#ft_raster_flag_xxx">FT_RASTER_FLAG_DIRECT</a></code> bit flags are set in <code>flags</code>, the raster calls an <code><a href="ft2-raster.html#ft_spanfunc">FT_SpanFunc</a></code> callback <code>gray_spans</code> with <code>user</code> data as an argument ignoring <code>target</code>. This allows direct composition over a pre-existing user surface to perform the span drawing and composition. To optionally clip the spans, set the <code><a href="ft2-raster.html#ft_raster_flag_xxx">FT_RASTER_FLAG_CLIP</a></code> flag and <code>clip_box</code>. The monochrome raster does not support the direct mode.</p> 1475<p>The gray-level rasterizer always uses 256 gray levels. If you want fewer gray levels, you have to use <code><a href="ft2-raster.html#ft_raster_flag_xxx">FT_RASTER_FLAG_DIRECT</a></code> and reduce the levels in the callback function.</p> 1476<hr> 1477 1478<h2 id="ft_raster_flag_xxx">FT_RASTER_FLAG_XXX<a class="headerlink" href="#ft_raster_flag_xxx" title="Permanent link">¶</a></h2> 1479<p>Defined in FT_IMAGE_H (freetype/ftimage.h).</p> 1480<div class = "codehilite"><pre><code>#<span class="keyword">define</span> <a href="ft2-raster.html#ft_raster_flag_default">FT_RASTER_FLAG_DEFAULT</a> 0x0 1481#<span class="keyword">define</span> <a href="ft2-raster.html#ft_raster_flag_aa">FT_RASTER_FLAG_AA</a> 0x1 1482#<span class="keyword">define</span> <a href="ft2-raster.html#ft_raster_flag_direct">FT_RASTER_FLAG_DIRECT</a> 0x2 1483#<span class="keyword">define</span> <a href="ft2-raster.html#ft_raster_flag_clip">FT_RASTER_FLAG_CLIP</a> 0x4 1484#<span class="keyword">define</span> <a href="ft2-raster.html#ft_raster_flag_sdf">FT_RASTER_FLAG_SDF</a> 0x8 1485 1486 /* these constants are deprecated; use the corresponding */ 1487 /* `<b>FT_RASTER_FLAG_XXX</b>` values instead */ 1488#<span class="keyword">define</span> ft_raster_flag_default <a href="ft2-raster.html#ft_raster_flag_default">FT_RASTER_FLAG_DEFAULT</a> 1489#<span class="keyword">define</span> ft_raster_flag_aa <a href="ft2-raster.html#ft_raster_flag_aa">FT_RASTER_FLAG_AA</a> 1490#<span class="keyword">define</span> ft_raster_flag_direct <a href="ft2-raster.html#ft_raster_flag_direct">FT_RASTER_FLAG_DIRECT</a> 1491#<span class="keyword">define</span> ft_raster_flag_clip <a href="ft2-raster.html#ft_raster_flag_clip">FT_RASTER_FLAG_CLIP</a> 1492</code></pre></div> 1493 1494<p>A list of bit flag constants as used in the <code>flags</code> field of a <code><a href="ft2-raster.html#ft_raster_params">FT_Raster_Params</a></code> structure.</p> 1495<h4>values</h4> 1496<table class="fields"> 1497<tr><td class="val" id="ft_raster_flag_default">FT_RASTER_FLAG_DEFAULT</td><td class="desc"> 1498<p>This value is 0.</p> 1499</td></tr> 1500<tr><td class="val" id="ft_raster_flag_aa">FT_RASTER_FLAG_AA</td><td class="desc"> 1501<p>This flag is set to indicate that an anti-aliased glyph image should be generated. Otherwise, it will be monochrome (1-bit).</p> 1502</td></tr> 1503<tr><td class="val" id="ft_raster_flag_direct">FT_RASTER_FLAG_DIRECT</td><td class="desc"> 1504<p>This flag is set to indicate direct rendering. In this mode, client applications must provide their own span callback. This lets them directly draw or compose over an existing bitmap. If this bit is <em>not</em> set, the target pixmap's buffer <em>must</em> be zeroed before rendering and the output will be clipped to its size.</p> 1505<p>Direct rendering is only possible with anti-aliased glyphs.</p> 1506</td></tr> 1507<tr><td class="val" id="ft_raster_flag_clip">FT_RASTER_FLAG_CLIP</td><td class="desc"> 1508<p>This flag is only used in direct rendering mode. If set, the output will be clipped to a box specified in the <code>clip_box</code> field of the <code><a href="ft2-raster.html#ft_raster_params">FT_Raster_Params</a></code> structure. Otherwise, the <code>clip_box</code> is effectively set to the bounding box and all spans are generated.</p> 1509</td></tr> 1510<tr><td class="val" id="ft_raster_flag_sdf">FT_RASTER_FLAG_SDF</td><td class="desc"> 1511<p>This flag is set to indicate that a signed distance field glyph image should be generated. This is only used while rendering with the <code><a href="ft2-base_interface.html#ft_render_mode">FT_RENDER_MODE_SDF</a></code> render mode.</p> 1512</td></tr> 1513</table> 1514 1515<hr> 1516 1517<h2 id="ft_raster">FT_Raster<a class="headerlink" href="#ft_raster" title="Permanent link">¶</a></h2> 1518<p>Defined in FT_IMAGE_H (freetype/ftimage.h).</p> 1519<div class = "codehilite"><pre><code> <span class="keyword">typedef</span> <span class="keyword">struct</span> FT_RasterRec_* <b>FT_Raster</b>; 1520</code></pre></div> 1521 1522<p>An opaque handle (pointer) to a raster object. Each object can be used independently to convert an outline into a bitmap or pixmap.</p> 1523<h4>note</h4> 1524 1525<p>In FreeType 2, all rasters are now encapsulated within specific <code><a href="ft2-module_management.html#ft_renderer">FT_Renderer</a></code> modules and only used in their context.</p> 1526<hr> 1527 1528<h2 id="ft_raster_newfunc">FT_Raster_NewFunc<a class="headerlink" href="#ft_raster_newfunc" title="Permanent link">¶</a></h2> 1529<p>Defined in FT_IMAGE_H (freetype/ftimage.h).</p> 1530<div class = "codehilite"><pre><code> <span class="keyword">typedef</span> <span class="keyword">int</span> 1531 (*<b>FT_Raster_NewFunc</b>)( <span class="keyword">void</span>* memory, 1532 <a href="ft2-raster.html#ft_raster">FT_Raster</a>* raster ); 1533 1534#<span class="keyword">define</span> FT_Raster_New_Func <b>FT_Raster_NewFunc</b> 1535</code></pre></div> 1536 1537<p>A function used to create a new raster object.</p> 1538<h4>input</h4> 1539<table class="fields"> 1540<tr><td class="val" id="memory">memory</td><td class="desc"> 1541<p>A handle to the memory allocator.</p> 1542</td></tr> 1543</table> 1544 1545<h4>output</h4> 1546<table class="fields"> 1547<tr><td class="val" id="raster">raster</td><td class="desc"> 1548<p>A handle to the new raster object.</p> 1549</td></tr> 1550</table> 1551 1552<h4>return</h4> 1553 1554<p>Error code. 0 means success.</p> 1555<h4>note</h4> 1556 1557<p>The <code>memory</code> parameter is a typeless pointer in order to avoid un-wanted dependencies on the rest of the FreeType code. In practice, it is an <code><a href="ft2-system_interface.html#ft_memory">FT_Memory</a></code> object, i.e., a handle to the standard FreeType memory allocator. However, this field can be completely ignored by a given raster implementation.</p> 1558<hr> 1559 1560<h2 id="ft_raster_donefunc">FT_Raster_DoneFunc<a class="headerlink" href="#ft_raster_donefunc" title="Permanent link">¶</a></h2> 1561<p>Defined in FT_IMAGE_H (freetype/ftimage.h).</p> 1562<div class = "codehilite"><pre><code> <span class="keyword">typedef</span> <span class="keyword">void</span> 1563 (*<b>FT_Raster_DoneFunc</b>)( <a href="ft2-raster.html#ft_raster">FT_Raster</a> raster ); 1564 1565#<span class="keyword">define</span> FT_Raster_Done_Func <b>FT_Raster_DoneFunc</b> 1566</code></pre></div> 1567 1568<p>A function used to destroy a given raster object.</p> 1569<h4>input</h4> 1570<table class="fields"> 1571<tr><td class="val" id="raster">raster</td><td class="desc"> 1572<p>A handle to the raster object.</p> 1573</td></tr> 1574</table> 1575 1576<hr> 1577 1578<h2 id="ft_raster_resetfunc">FT_Raster_ResetFunc<a class="headerlink" href="#ft_raster_resetfunc" title="Permanent link">¶</a></h2> 1579<p>Defined in FT_IMAGE_H (freetype/ftimage.h).</p> 1580<div class = "codehilite"><pre><code> <span class="keyword">typedef</span> <span class="keyword">void</span> 1581 (*<b>FT_Raster_ResetFunc</b>)( <a href="ft2-raster.html#ft_raster">FT_Raster</a> raster, 1582 <span class="keyword">unsigned</span> <span class="keyword">char</span>* pool_base, 1583 <span class="keyword">unsigned</span> <span class="keyword">long</span> pool_size ); 1584 1585#<span class="keyword">define</span> FT_Raster_Reset_Func <b>FT_Raster_ResetFunc</b> 1586</code></pre></div> 1587 1588<p>FreeType used to provide an area of memory called the ‘render pool’ available to all registered rasterizers. This was not thread safe, however, and now FreeType never allocates this pool.</p> 1589<p>This function is called after a new raster object is created.</p> 1590<h4>input</h4> 1591<table class="fields"> 1592<tr><td class="val" id="raster">raster</td><td class="desc"> 1593<p>A handle to the new raster object.</p> 1594</td></tr> 1595<tr><td class="val" id="pool_base">pool_base</td><td class="desc"> 1596<p>Previously, the address in memory of the render pool. Set this to <code>NULL</code>.</p> 1597</td></tr> 1598<tr><td class="val" id="pool_size">pool_size</td><td class="desc"> 1599<p>Previously, the size in bytes of the render pool. Set this to 0.</p> 1600</td></tr> 1601</table> 1602 1603<h4>note</h4> 1604 1605<p>Rasterizers should rely on dynamic or stack allocation if they want to (a handle to the memory allocator is passed to the rasterizer constructor).</p> 1606<hr> 1607 1608<h2 id="ft_raster_setmodefunc">FT_Raster_SetModeFunc<a class="headerlink" href="#ft_raster_setmodefunc" title="Permanent link">¶</a></h2> 1609<p>Defined in FT_IMAGE_H (freetype/ftimage.h).</p> 1610<div class = "codehilite"><pre><code> <span class="keyword">typedef</span> <span class="keyword">int</span> 1611 (*<b>FT_Raster_SetModeFunc</b>)( <a href="ft2-raster.html#ft_raster">FT_Raster</a> raster, 1612 <span class="keyword">unsigned</span> <span class="keyword">long</span> mode, 1613 <span class="keyword">void</span>* args ); 1614 1615#<span class="keyword">define</span> FT_Raster_Set_Mode_Func <b>FT_Raster_SetModeFunc</b> 1616</code></pre></div> 1617 1618<p>This function is a generic facility to change modes or attributes in a given raster. This can be used for debugging purposes, or simply to allow implementation-specific ‘features’ in a given raster module.</p> 1619<h4>input</h4> 1620<table class="fields"> 1621<tr><td class="val" id="raster">raster</td><td class="desc"> 1622<p>A handle to the new raster object.</p> 1623</td></tr> 1624<tr><td class="val" id="mode">mode</td><td class="desc"> 1625<p>A 4-byte tag used to name the mode or property.</p> 1626</td></tr> 1627<tr><td class="val" id="args">args</td><td class="desc"> 1628<p>A pointer to the new mode/property to use.</p> 1629</td></tr> 1630</table> 1631 1632<hr> 1633 1634<h2 id="ft_raster_renderfunc">FT_Raster_RenderFunc<a class="headerlink" href="#ft_raster_renderfunc" title="Permanent link">¶</a></h2> 1635<p>Defined in FT_IMAGE_H (freetype/ftimage.h).</p> 1636<div class = "codehilite"><pre><code> <span class="keyword">typedef</span> <span class="keyword">int</span> 1637 (*<b>FT_Raster_RenderFunc</b>)( <a href="ft2-raster.html#ft_raster">FT_Raster</a> raster, 1638 <span class="keyword">const</span> <a href="ft2-raster.html#ft_raster_params">FT_Raster_Params</a>* params ); 1639 1640#<span class="keyword">define</span> FT_Raster_Render_Func <b>FT_Raster_RenderFunc</b> 1641</code></pre></div> 1642 1643<p>Invoke a given raster to scan-convert a given glyph image into a target bitmap.</p> 1644<h4>input</h4> 1645<table class="fields"> 1646<tr><td class="val" id="raster">raster</td><td class="desc"> 1647<p>A handle to the raster object.</p> 1648</td></tr> 1649<tr><td class="val" id="params">params</td><td class="desc"> 1650<p>A pointer to an <code><a href="ft2-raster.html#ft_raster_params">FT_Raster_Params</a></code> structure used to store the rendering parameters.</p> 1651</td></tr> 1652</table> 1653 1654<h4>return</h4> 1655 1656<p>Error code. 0 means success.</p> 1657<h4>note</h4> 1658 1659<p>The exact format of the source image depends on the raster's glyph format defined in its <code><a href="ft2-raster.html#ft_raster_funcs">FT_Raster_Funcs</a></code> structure. It can be an <code><a href="ft2-outline_processing.html#ft_outline">FT_Outline</a></code> or anything else in order to support a large array of glyph formats.</p> 1660<p>Note also that the render function can fail and return a <code>FT_Err_Unimplemented_Feature</code> error code if the raster used does not support direct composition.</p> 1661<hr> 1662 1663<h2 id="ft_raster_funcs">FT_Raster_Funcs<a class="headerlink" href="#ft_raster_funcs" title="Permanent link">¶</a></h2> 1664<p>Defined in FT_IMAGE_H (freetype/ftimage.h).</p> 1665<div class = "codehilite"><pre><code> <span class="keyword">typedef</span> <span class="keyword">struct</span> FT_Raster_Funcs_ 1666 { 1667 <a href="ft2-basic_types.html#ft_glyph_format">FT_Glyph_Format</a> glyph_format; 1668 1669 <a href="ft2-raster.html#ft_raster_newfunc">FT_Raster_NewFunc</a> raster_new; 1670 <a href="ft2-raster.html#ft_raster_resetfunc">FT_Raster_ResetFunc</a> raster_reset; 1671 <a href="ft2-raster.html#ft_raster_setmodefunc">FT_Raster_SetModeFunc</a> raster_set_mode; 1672 <a href="ft2-raster.html#ft_raster_renderfunc">FT_Raster_RenderFunc</a> raster_render; 1673 <a href="ft2-raster.html#ft_raster_donefunc">FT_Raster_DoneFunc</a> raster_done; 1674 1675 } <b>FT_Raster_Funcs</b>; 1676</code></pre></div> 1677 1678<p>A structure used to describe a given raster class to the library.</p> 1679<h4>fields</h4> 1680<table class="fields"> 1681<tr><td class="val" id="glyph_format">glyph_format</td><td class="desc"> 1682<p>The supported glyph format for this raster.</p> 1683</td></tr> 1684<tr><td class="val" id="raster_new">raster_new</td><td class="desc"> 1685<p>The raster constructor.</p> 1686</td></tr> 1687<tr><td class="val" id="raster_reset">raster_reset</td><td class="desc"> 1688<p>Used to reset the render pool within the raster.</p> 1689</td></tr> 1690<tr><td class="val" id="raster_render">raster_render</td><td class="desc"> 1691<p>A function to render a glyph into a given bitmap.</p> 1692</td></tr> 1693<tr><td class="val" id="raster_done">raster_done</td><td class="desc"> 1694<p>The raster destructor.</p> 1695</td></tr> 1696</table> 1697 1698<hr> 1699 1700<h2 id="ft_raster_bittest_func">FT_Raster_BitTest_Func<a class="headerlink" href="#ft_raster_bittest_func" title="Permanent link">¶</a></h2> 1701<p>Defined in FT_IMAGE_H (freetype/ftimage.h).</p> 1702<div class = "codehilite"><pre><code> <span class="keyword">typedef</span> <span class="keyword">int</span> 1703 (*<b>FT_Raster_BitTest_Func</b>)( <span class="keyword">int</span> y, 1704 <span class="keyword">int</span> x, 1705 <span class="keyword">void</span>* user ); 1706</code></pre></div> 1707 1708<p>Deprecated, unimplemented.</p> 1709<hr> 1710 1711<h2 id="ft_raster_bitset_func">FT_Raster_BitSet_Func<a class="headerlink" href="#ft_raster_bitset_func" title="Permanent link">¶</a></h2> 1712<p>Defined in FT_IMAGE_H (freetype/ftimage.h).</p> 1713<div class = "codehilite"><pre><code> <span class="keyword">typedef</span> <span class="keyword">void</span> 1714 (*<b>FT_Raster_BitSet_Func</b>)( <span class="keyword">int</span> y, 1715 <span class="keyword">int</span> x, 1716 <span class="keyword">void</span>* user ); 1717</code></pre></div> 1718 1719<p>Deprecated, unimplemented.</p> 1720<hr> 1721 1722 1723 1724 1725 1726 1727 1728 </article> 1729 </div> 1730 </div> 1731 1732 </main> 1733 1734 1735<footer class="md-footer"> 1736 1737 <nav class="md-footer__inner md-grid" aria-label="Footer"> 1738 1739 1740 <a href="ft2-bitmap_handling.html" class="md-footer__link md-footer__link--prev" aria-label="Previous: Bitmap Handling" rel="prev"> 1741 <div class="md-footer__button md-icon"> 1742 <svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24"><path d="M20 11v2H8l5.5 5.5-1.42 1.42L4.16 12l7.92-7.92L13.5 5.5 8 11h12z"/></svg> 1743 </div> 1744 <div class="md-footer__title"> 1745 <div class="md-ellipsis"> 1746 <span class="md-footer__direction"> 1747 Previous 1748 </span> 1749 Bitmap Handling 1750 </div> 1751 </div> 1752 </a> 1753 1754 1755 1756 <a href="ft2-glyph_stroker.html" class="md-footer__link md-footer__link--next" aria-label="Next: Glyph Stroker" rel="next"> 1757 <div class="md-footer__title"> 1758 <div class="md-ellipsis"> 1759 <span class="md-footer__direction"> 1760 Next 1761 </span> 1762 Glyph Stroker 1763 </div> 1764 </div> 1765 <div class="md-footer__button md-icon"> 1766 <svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24"><path d="M4 11v2h12l-5.5 5.5 1.42 1.42L19.84 12l-7.92-7.92L10.5 5.5 16 11H4z"/></svg> 1767 </div> 1768 </a> 1769 1770 </nav> 1771 1772 <div class="md-footer-meta md-typeset"> 1773 <div class="md-footer-meta__inner md-grid"> 1774 <div class="md-footer-copyright"> 1775 1776 <div class="md-footer-copyright__highlight"> 1777 Copyright 2022 <a href = "https://www.freetype.org/license.html">The FreeType Project</a>. 1778 </div> 1779 1780 Made with 1781 <a href="https://squidfunk.github.io/mkdocs-material/" target="_blank" rel="noopener"> 1782 Material for MkDocs 1783 </a> 1784 1785 </div> 1786 1787 </div> 1788 </div> 1789</footer> 1790 1791 </div> 1792 <div class="md-dialog" data-md-component="dialog"> 1793 <div class="md-dialog__inner md-typeset"></div> 1794 </div> 1795 <script id="__config" type="application/json">{"base": ".", "features": [], "translations": {"clipboard.copy": "Copy to clipboard", "clipboard.copied": "Copied to clipboard", "search.config.lang": "en", "search.config.pipeline": "trimmer, stopWordFilter", "search.config.separator": "[\\s\\-]+", "search.placeholder": "Search", "search.result.placeholder": "Type to start searching", "search.result.none": "No matching documents", "search.result.one": "1 matching document", "search.result.other": "# matching documents", "search.result.more.one": "1 more on this page", "search.result.more.other": "# more on this page", "search.result.term.missing": "Missing", "select.version.title": "Select version"}, "search": "assets/javascripts/workers/search.477d984a.min.js", "version": null}</script> 1796 1797 1798 <script src="assets/javascripts/bundle.82b56eb2.min.js"></script> 1799 1800 <script src="javascripts/extra.js"></script> 1801 1802 1803 </body> 1804</html>