/usr/include/freetype2/ftcache.h is in libfreetype6-dev 2.5.2-1ubuntu2.8.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736 737 738 739 740 741 742 743 744 745 746 747 748 749 750 751 752 753 754 755 756 757 758 759 760 761 762 763 764 765 766 767 768 769 770 771 772 773 774 775 776 777 778 779 780 781 782 783 784 785 786 787 788 789 790 791 792 793 794 795 796 797 798 799 800 801 802 803 804 805 806 807 808 809 810 811 812 813 814 815 816 817 818 819 820 821 822 823 824 825 826 827 828 829 830 831 832 833 834 835 836 837 838 839 840 841 842 843 844 845 846 847 848 849 850 851 852 853 854 855 856 857 858 859 860 861 862 863 864 865 866 867 868 869 870 871 872 873 874 875 876 877 878 879 880 881 882 883 884 885 886 887 888 889 890 891 892 893 894 895 896 897 898 899 900 901 902 903 904 905 906 907 908 909 910 911 912 913 914 915 916 917 918 919 920 921 922 923 924 925 926 927 928 929 930 931 932 933 934 935 936 937 938 939 940 941 942 943 944 945 946 947 948 949 950 951 952 953 954 955 956 957 958 959 960 961 962 963 964 965 966 967 968 969 970 971 972 973 974 975 976 977 978 979 980 981 982 983 984 985 986 987 988 989 990 991 992 993 994 995 996 997 998 999 1000 1001 1002 1003 1004 1005 1006 1007 1008 1009 1010 1011 1012 1013 1014 1015 1016 1017 1018 1019 1020 1021 1022 1023 1024 1025 1026 1027 1028 1029 1030 1031 1032 1033 1034 1035 1036 1037 1038 1039 1040 1041 1042 1043 1044 1045 1046 1047 1048 1049 1050 1051 1052 1053 1054 1055 1056 1057 | /***************************************************************************/
/* */
/* ftcache.h */
/* */
/* FreeType Cache subsystem (specification). */
/* */
/* Copyright 1996-2008, 2010, 2013 by */
/* David Turner, Robert Wilhelm, and Werner Lemberg. */
/* */
/* This file is part of the FreeType project, and may only be used, */
/* modified, and distributed under the terms of the FreeType project */
/* license, LICENSE.TXT. By continuing to use, modify, or distribute */
/* this file you indicate that you have read the license and */
/* understand and accept it fully. */
/* */
/***************************************************************************/
#ifndef __FTCACHE_H__
#define __FTCACHE_H__
#include <ft2build.h>
#include FT_GLYPH_H
FT_BEGIN_HEADER
/*************************************************************************
*
* <Section>
* cache_subsystem
*
* <Title>
* Cache Sub-System
*
* <Abstract>
* How to cache face, size, and glyph data with FreeType~2.
*
* <Description>
* This section describes the FreeType~2 cache sub-system, which is used
* to limit the number of concurrently opened @FT_Face and @FT_Size
* objects, as well as caching information like character maps and glyph
* images while limiting their maximum memory usage.
*
* Note that all types and functions begin with the `FTC_' prefix.
*
* The cache is highly portable and thus doesn't know anything about the
* fonts installed on your system, or how to access them. This implies
* the following scheme:
*
* First, available or installed font faces are uniquely identified by
* @FTC_FaceID values, provided to the cache by the client. Note that
* the cache only stores and compares these values, and doesn't try to
* interpret them in any way.
*
* Second, the cache calls, only when needed, a client-provided function
* to convert an @FTC_FaceID into a new @FT_Face object. The latter is
* then completely managed by the cache, including its termination
* through @FT_Done_Face. To monitor termination of face objects, the
* finalizer callback in the `generic' field of the @FT_Face object can
* be used, which might also be used to store the @FTC_FaceID of the
* face.
*
* Clients are free to map face IDs to anything else. The most simple
* usage is to associate them to a (pathname,face_index) pair that is
* used to call @FT_New_Face. However, more complex schemes are also
* possible.
*
* Note that for the cache to work correctly, the face ID values must be
* *persistent*, which means that the contents they point to should not
* change at runtime, or that their value should not become invalid.
*
* If this is unavoidable (e.g., when a font is uninstalled at runtime),
* you should call @FTC_Manager_RemoveFaceID as soon as possible, to let
* the cache get rid of any references to the old @FTC_FaceID it may
* keep internally. Failure to do so will lead to incorrect behaviour
* or even crashes.
*
* To use the cache, start with calling @FTC_Manager_New to create a new
* @FTC_Manager object, which models a single cache instance. You can
* then look up @FT_Face and @FT_Size objects with
* @FTC_Manager_LookupFace and @FTC_Manager_LookupSize, respectively.
*
* If you want to use the charmap caching, call @FTC_CMapCache_New, then
* later use @FTC_CMapCache_Lookup to perform the equivalent of
* @FT_Get_Char_Index, only much faster.
*
* If you want to use the @FT_Glyph caching, call @FTC_ImageCache, then
* later use @FTC_ImageCache_Lookup to retrieve the corresponding
* @FT_Glyph objects from the cache.
*
* If you need lots of small bitmaps, it is much more memory efficient
* to call @FTC_SBitCache_New followed by @FTC_SBitCache_Lookup. This
* returns @FTC_SBitRec structures, which are used to store small
* bitmaps directly. (A small bitmap is one whose metrics and
* dimensions all fit into 8-bit integers).
*
* We hope to also provide a kerning cache in the near future.
*
*
* <Order>
* FTC_Manager
* FTC_FaceID
* FTC_Face_Requester
*
* FTC_Manager_New
* FTC_Manager_Reset
* FTC_Manager_Done
* FTC_Manager_LookupFace
* FTC_Manager_LookupSize
* FTC_Manager_RemoveFaceID
*
* FTC_Node
* FTC_Node_Unref
*
* FTC_ImageCache
* FTC_ImageCache_New
* FTC_ImageCache_Lookup
*
* FTC_SBit
* FTC_SBitCache
* FTC_SBitCache_New
* FTC_SBitCache_Lookup
*
* FTC_CMapCache
* FTC_CMapCache_New
* FTC_CMapCache_Lookup
*
*************************************************************************/
/*************************************************************************/
/*************************************************************************/
/*************************************************************************/
/***** *****/
/***** BASIC TYPE DEFINITIONS *****/
/***** *****/
/*************************************************************************/
/*************************************************************************/
/*************************************************************************/
/*************************************************************************
*
* @type: FTC_FaceID
*
* @description:
* An opaque pointer type that is used to identity face objects. The
* contents of such objects is application-dependent.
*
* These pointers are typically used to point to a user-defined
* structure containing a font file path, and face index.
*
* @note:
* Never use NULL as a valid @FTC_FaceID.
*
* Face IDs are passed by the client to the cache manager that calls,
* when needed, the @FTC_Face_Requester to translate them into new
* @FT_Face objects.
*
* If the content of a given face ID changes at runtime, or if the value
* becomes invalid (e.g., when uninstalling a font), you should
* immediately call @FTC_Manager_RemoveFaceID before any other cache
* function.
*
* Failure to do so will result in incorrect behaviour or even
* memory leaks and crashes.
*/
typedef FT_Pointer FTC_FaceID;
/************************************************************************
*
* @functype:
* FTC_Face_Requester
*
* @description:
* A callback function provided by client applications. It is used by
* the cache manager to translate a given @FTC_FaceID into a new valid
* @FT_Face object, on demand.
*
* <Input>
* face_id ::
* The face ID to resolve.
*
* library ::
* A handle to a FreeType library object.
*
* req_data ::
* Application-provided request data (see note below).
*
* <Output>
* aface ::
* A new @FT_Face handle.
*
* <Return>
* FreeType error code. 0~means success.
*
* <Note>
* The third parameter `req_data' is the same as the one passed by the
* client when @FTC_Manager_New is called.
*
* The face requester should not perform funny things on the returned
* face object, like creating a new @FT_Size for it, or setting a
* transformation through @FT_Set_Transform!
*/
typedef FT_Error
(*FTC_Face_Requester)( FTC_FaceID face_id,
FT_Library library,
FT_Pointer request_data,
FT_Face* aface );
/* */
/*************************************************************************/
/*************************************************************************/
/*************************************************************************/
/***** *****/
/***** CACHE MANAGER OBJECT *****/
/***** *****/
/*************************************************************************/
/*************************************************************************/
/*************************************************************************/
/*************************************************************************/
/* */
/* <Type> */
/* FTC_Manager */
/* */
/* <Description> */
/* This object corresponds to one instance of the cache-subsystem. */
/* It is used to cache one or more @FT_Face objects, along with */
/* corresponding @FT_Size objects. */
/* */
/* The manager intentionally limits the total number of opened */
/* @FT_Face and @FT_Size objects to control memory usage. See the */
/* `max_faces' and `max_sizes' parameters of @FTC_Manager_New. */
/* */
/* The manager is also used to cache `nodes' of various types while */
/* limiting their total memory usage. */
/* */
/* All limitations are enforced by keeping lists of managed objects */
/* in most-recently-used order, and flushing old nodes to make room */
/* for new ones. */
/* */
typedef struct FTC_ManagerRec_* FTC_Manager;
/*************************************************************************/
/* */
/* <Type> */
/* FTC_Node */
/* */
/* <Description> */
/* An opaque handle to a cache node object. Each cache node is */
/* reference-counted. A node with a count of~0 might be flushed */
/* out of a full cache whenever a lookup request is performed. */
/* */
/* If you look up nodes, you have the ability to `acquire' them, */
/* i.e., to increment their reference count. This will prevent the */
/* node from being flushed out of the cache until you explicitly */
/* `release' it (see @FTC_Node_Unref). */
/* */
/* See also @FTC_SBitCache_Lookup and @FTC_ImageCache_Lookup. */
/* */
typedef struct FTC_NodeRec_* FTC_Node;
/*************************************************************************/
/* */
/* <Function> */
/* FTC_Manager_New */
/* */
/* <Description> */
/* Create a new cache manager. */
/* */
/* <Input> */
/* library :: The parent FreeType library handle to use. */
/* */
/* max_faces :: Maximum number of opened @FT_Face objects managed by */
/* this cache instance. Use~0 for defaults. */
/* */
/* max_sizes :: Maximum number of opened @FT_Size objects managed by */
/* this cache instance. Use~0 for defaults. */
/* */
/* max_bytes :: Maximum number of bytes to use for cached data nodes. */
/* Use~0 for defaults. Note that this value does not */
/* account for managed @FT_Face and @FT_Size objects. */
/* */
/* requester :: An application-provided callback used to translate */
/* face IDs into real @FT_Face objects. */
/* */
/* req_data :: A generic pointer that is passed to the requester */
/* each time it is called (see @FTC_Face_Requester). */
/* */
/* <Output> */
/* amanager :: A handle to a new manager object. 0~in case of */
/* failure. */
/* */
/* <Return> */
/* FreeType error code. 0~means success. */
/* */
FT_EXPORT( FT_Error )
FTC_Manager_New( FT_Library library,
FT_UInt max_faces,
FT_UInt max_sizes,
FT_ULong max_bytes,
FTC_Face_Requester requester,
FT_Pointer req_data,
FTC_Manager *amanager );
/*************************************************************************/
/* */
/* <Function> */
/* FTC_Manager_Reset */
/* */
/* <Description> */
/* Empty a given cache manager. This simply gets rid of all the */
/* currently cached @FT_Face and @FT_Size objects within the manager. */
/* */
/* <InOut> */
/* manager :: A handle to the manager. */
/* */
FT_EXPORT( void )
FTC_Manager_Reset( FTC_Manager manager );
/*************************************************************************/
/* */
/* <Function> */
/* FTC_Manager_Done */
/* */
/* <Description> */
/* Destroy a given manager after emptying it. */
/* */
/* <Input> */
/* manager :: A handle to the target cache manager object. */
/* */
FT_EXPORT( void )
FTC_Manager_Done( FTC_Manager manager );
/*************************************************************************/
/* */
/* <Function> */
/* FTC_Manager_LookupFace */
/* */
/* <Description> */
/* Retrieve the @FT_Face object that corresponds to a given face ID */
/* through a cache manager. */
/* */
/* <Input> */
/* manager :: A handle to the cache manager. */
/* */
/* face_id :: The ID of the face object. */
/* */
/* <Output> */
/* aface :: A handle to the face object. */
/* */
/* <Return> */
/* FreeType error code. 0~means success. */
/* */
/* <Note> */
/* The returned @FT_Face object is always owned by the manager. You */
/* should never try to discard it yourself. */
/* */
/* The @FT_Face object doesn't necessarily have a current size object */
/* (i.e., face->size can be~0). If you need a specific `font size', */
/* use @FTC_Manager_LookupSize instead. */
/* */
/* Never change the face's transformation matrix (i.e., never call */
/* the @FT_Set_Transform function) on a returned face! If you need */
/* to transform glyphs, do it yourself after glyph loading. */
/* */
/* When you perform a lookup, out-of-memory errors are detected */
/* _within_ the lookup and force incremental flushes of the cache */
/* until enough memory is released for the lookup to succeed. */
/* */
/* If a lookup fails with `FT_Err_Out_Of_Memory' the cache has */
/* already been completely flushed, and still no memory was available */
/* for the operation. */
/* */
FT_EXPORT( FT_Error )
FTC_Manager_LookupFace( FTC_Manager manager,
FTC_FaceID face_id,
FT_Face *aface );
/*************************************************************************/
/* */
/* <Struct> */
/* FTC_ScalerRec */
/* */
/* <Description> */
/* A structure used to describe a given character size in either */
/* pixels or points to the cache manager. See */
/* @FTC_Manager_LookupSize. */
/* */
/* <Fields> */
/* face_id :: The source face ID. */
/* */
/* width :: The character width. */
/* */
/* height :: The character height. */
/* */
/* pixel :: A Boolean. If 1, the `width' and `height' fields are */
/* interpreted as integer pixel character sizes. */
/* Otherwise, they are expressed as 1/64th of points. */
/* */
/* x_res :: Only used when `pixel' is value~0 to indicate the */
/* horizontal resolution in dpi. */
/* */
/* y_res :: Only used when `pixel' is value~0 to indicate the */
/* vertical resolution in dpi. */
/* */
/* <Note> */
/* This type is mainly used to retrieve @FT_Size objects through the */
/* cache manager. */
/* */
typedef struct FTC_ScalerRec_
{
FTC_FaceID face_id;
FT_UInt width;
FT_UInt height;
FT_Int pixel;
FT_UInt x_res;
FT_UInt y_res;
} FTC_ScalerRec;
/*************************************************************************/
/* */
/* <Struct> */
/* FTC_Scaler */
/* */
/* <Description> */
/* A handle to an @FTC_ScalerRec structure. */
/* */
typedef struct FTC_ScalerRec_* FTC_Scaler;
/*************************************************************************/
/* */
/* <Function> */
/* FTC_Manager_LookupSize */
/* */
/* <Description> */
/* Retrieve the @FT_Size object that corresponds to a given */
/* @FTC_ScalerRec pointer through a cache manager. */
/* */
/* <Input> */
/* manager :: A handle to the cache manager. */
/* */
/* scaler :: A scaler handle. */
/* */
/* <Output> */
/* asize :: A handle to the size object. */
/* */
/* <Return> */
/* FreeType error code. 0~means success. */
/* */
/* <Note> */
/* The returned @FT_Size object is always owned by the manager. You */
/* should never try to discard it by yourself. */
/* */
/* You can access the parent @FT_Face object simply as `size->face' */
/* if you need it. Note that this object is also owned by the */
/* manager. */
/* */
/* <Note> */
/* When you perform a lookup, out-of-memory errors are detected */
/* _within_ the lookup and force incremental flushes of the cache */
/* until enough memory is released for the lookup to succeed. */
/* */
/* If a lookup fails with `FT_Err_Out_Of_Memory' the cache has */
/* already been completely flushed, and still no memory is available */
/* for the operation. */
/* */
FT_EXPORT( FT_Error )
FTC_Manager_LookupSize( FTC_Manager manager,
FTC_Scaler scaler,
FT_Size *asize );
/*************************************************************************/
/* */
/* <Function> */
/* FTC_Node_Unref */
/* */
/* <Description> */
/* Decrement a cache node's internal reference count. When the count */
/* reaches 0, it is not destroyed but becomes eligible for subsequent */
/* cache flushes. */
/* */
/* <Input> */
/* node :: The cache node handle. */
/* */
/* manager :: The cache manager handle. */
/* */
FT_EXPORT( void )
FTC_Node_Unref( FTC_Node node,
FTC_Manager manager );
/*************************************************************************
*
* @function:
* FTC_Manager_RemoveFaceID
*
* @description:
* A special function used to indicate to the cache manager that
* a given @FTC_FaceID is no longer valid, either because its
* content changed, or because it was deallocated or uninstalled.
*
* @input:
* manager ::
* The cache manager handle.
*
* face_id ::
* The @FTC_FaceID to be removed.
*
* @note:
* This function flushes all nodes from the cache corresponding to this
* `face_id', with the exception of nodes with a non-null reference
* count.
*
* Such nodes are however modified internally so as to never appear
* in later lookups with the same `face_id' value, and to be immediately
* destroyed when released by all their users.
*
*/
FT_EXPORT( void )
FTC_Manager_RemoveFaceID( FTC_Manager manager,
FTC_FaceID face_id );
/*************************************************************************/
/* */
/* <Section> */
/* cache_subsystem */
/* */
/*************************************************************************/
/*************************************************************************
*
* @type:
* FTC_CMapCache
*
* @description:
* An opaque handle used to model a charmap cache. This cache is to
* hold character codes -> glyph indices mappings.
*
*/
typedef struct FTC_CMapCacheRec_* FTC_CMapCache;
/*************************************************************************
*
* @function:
* FTC_CMapCache_New
*
* @description:
* Create a new charmap cache.
*
* @input:
* manager ::
* A handle to the cache manager.
*
* @output:
* acache ::
* A new cache handle. NULL in case of error.
*
* @return:
* FreeType error code. 0~means success.
*
* @note:
* Like all other caches, this one will be destroyed with the cache
* manager.
*
*/
FT_EXPORT( FT_Error )
FTC_CMapCache_New( FTC_Manager manager,
FTC_CMapCache *acache );
/************************************************************************
*
* @function:
* FTC_CMapCache_Lookup
*
* @description:
* Translate a character code into a glyph index, using the charmap
* cache.
*
* @input:
* cache ::
* A charmap cache handle.
*
* face_id ::
* The source face ID.
*
* cmap_index ::
* The index of the charmap in the source face. Any negative value
* means to use the cache @FT_Face's default charmap.
*
* char_code ::
* The character code (in the corresponding charmap).
*
* @return:
* Glyph index. 0~means `no glyph'.
*
*/
FT_EXPORT( FT_UInt )
FTC_CMapCache_Lookup( FTC_CMapCache cache,
FTC_FaceID face_id,
FT_Int cmap_index,
FT_UInt32 char_code );
/*************************************************************************/
/* */
/* <Section> */
/* cache_subsystem */
/* */
/*************************************************************************/
/*************************************************************************/
/*************************************************************************/
/*************************************************************************/
/***** *****/
/***** IMAGE CACHE OBJECT *****/
/***** *****/
/*************************************************************************/
/*************************************************************************/
/*************************************************************************/
/*************************************************************************
*
* @struct:
* FTC_ImageTypeRec
*
* @description:
* A structure used to model the type of images in a glyph cache.
*
* @fields:
* face_id ::
* The face ID.
*
* width ::
* The width in pixels.
*
* height ::
* The height in pixels.
*
* flags ::
* The load flags, as in @FT_Load_Glyph.
*
*/
typedef struct FTC_ImageTypeRec_
{
FTC_FaceID face_id;
FT_Int width;
FT_Int height;
FT_Int32 flags;
} FTC_ImageTypeRec;
/*************************************************************************
*
* @type:
* FTC_ImageType
*
* @description:
* A handle to an @FTC_ImageTypeRec structure.
*
*/
typedef struct FTC_ImageTypeRec_* FTC_ImageType;
/* */
#define FTC_IMAGE_TYPE_COMPARE( d1, d2 ) \
( (d1)->face_id == (d2)->face_id && \
(d1)->width == (d2)->width && \
(d1)->flags == (d2)->flags )
/*************************************************************************/
/* */
/* <Type> */
/* FTC_ImageCache */
/* */
/* <Description> */
/* A handle to a glyph image cache object. They are designed to */
/* hold many distinct glyph images while not exceeding a certain */
/* memory threshold. */
/* */
typedef struct FTC_ImageCacheRec_* FTC_ImageCache;
/*************************************************************************/
/* */
/* <Function> */
/* FTC_ImageCache_New */
/* */
/* <Description> */
/* Create a new glyph image cache. */
/* */
/* <Input> */
/* manager :: The parent manager for the image cache. */
/* */
/* <Output> */
/* acache :: A handle to the new glyph image cache object. */
/* */
/* <Return> */
/* FreeType error code. 0~means success. */
/* */
FT_EXPORT( FT_Error )
FTC_ImageCache_New( FTC_Manager manager,
FTC_ImageCache *acache );
/*************************************************************************/
/* */
/* <Function> */
/* FTC_ImageCache_Lookup */
/* */
/* <Description> */
/* Retrieve a given glyph image from a glyph image cache. */
/* */
/* <Input> */
/* cache :: A handle to the source glyph image cache. */
/* */
/* type :: A pointer to a glyph image type descriptor. */
/* */
/* gindex :: The glyph index to retrieve. */
/* */
/* <Output> */
/* aglyph :: The corresponding @FT_Glyph object. 0~in case of */
/* failure. */
/* */
/* anode :: Used to return the address of of the corresponding cache */
/* node after incrementing its reference count (see note */
/* below). */
/* */
/* <Return> */
/* FreeType error code. 0~means success. */
/* */
/* <Note> */
/* The returned glyph is owned and managed by the glyph image cache. */
/* Never try to transform or discard it manually! You can however */
/* create a copy with @FT_Glyph_Copy and modify the new one. */
/* */
/* If `anode' is _not_ NULL, it receives the address of the cache */
/* node containing the glyph image, after increasing its reference */
/* count. This ensures that the node (as well as the @FT_Glyph) will */
/* always be kept in the cache until you call @FTC_Node_Unref to */
/* `release' it. */
/* */
/* If `anode' is NULL, the cache node is left unchanged, which means */
/* that the @FT_Glyph could be flushed out of the cache on the next */
/* call to one of the caching sub-system APIs. Don't assume that it */
/* is persistent! */
/* */
FT_EXPORT( FT_Error )
FTC_ImageCache_Lookup( FTC_ImageCache cache,
FTC_ImageType type,
FT_UInt gindex,
FT_Glyph *aglyph,
FTC_Node *anode );
/*************************************************************************/
/* */
/* <Function> */
/* FTC_ImageCache_LookupScaler */
/* */
/* <Description> */
/* A variant of @FTC_ImageCache_Lookup that uses an @FTC_ScalerRec */
/* to specify the face ID and its size. */
/* */
/* <Input> */
/* cache :: A handle to the source glyph image cache. */
/* */
/* scaler :: A pointer to a scaler descriptor. */
/* */
/* load_flags :: The corresponding load flags. */
/* */
/* gindex :: The glyph index to retrieve. */
/* */
/* <Output> */
/* aglyph :: The corresponding @FT_Glyph object. 0~in case of */
/* failure. */
/* */
/* anode :: Used to return the address of of the corresponding */
/* cache node after incrementing its reference count */
/* (see note below). */
/* */
/* <Return> */
/* FreeType error code. 0~means success. */
/* */
/* <Note> */
/* The returned glyph is owned and managed by the glyph image cache. */
/* Never try to transform or discard it manually! You can however */
/* create a copy with @FT_Glyph_Copy and modify the new one. */
/* */
/* If `anode' is _not_ NULL, it receives the address of the cache */
/* node containing the glyph image, after increasing its reference */
/* count. This ensures that the node (as well as the @FT_Glyph) will */
/* always be kept in the cache until you call @FTC_Node_Unref to */
/* `release' it. */
/* */
/* If `anode' is NULL, the cache node is left unchanged, which means */
/* that the @FT_Glyph could be flushed out of the cache on the next */
/* call to one of the caching sub-system APIs. Don't assume that it */
/* is persistent! */
/* */
/* Calls to @FT_Set_Char_Size and friends have no effect on cached */
/* glyphs; you should always use the FreeType cache API instead. */
/* */
FT_EXPORT( FT_Error )
FTC_ImageCache_LookupScaler( FTC_ImageCache cache,
FTC_Scaler scaler,
FT_ULong load_flags,
FT_UInt gindex,
FT_Glyph *aglyph,
FTC_Node *anode );
/*************************************************************************/
/* */
/* <Type> */
/* FTC_SBit */
/* */
/* <Description> */
/* A handle to a small bitmap descriptor. See the @FTC_SBitRec */
/* structure for details. */
/* */
typedef struct FTC_SBitRec_* FTC_SBit;
/*************************************************************************/
/* */
/* <Struct> */
/* FTC_SBitRec */
/* */
/* <Description> */
/* A very compact structure used to describe a small glyph bitmap. */
/* */
/* <Fields> */
/* width :: The bitmap width in pixels. */
/* */
/* height :: The bitmap height in pixels. */
/* */
/* left :: The horizontal distance from the pen position to the */
/* left bitmap border (a.k.a. `left side bearing', or */
/* `lsb'). */
/* */
/* top :: The vertical distance from the pen position (on the */
/* baseline) to the upper bitmap border (a.k.a. `top */
/* side bearing'). The distance is positive for upwards */
/* y~coordinates. */
/* */
/* format :: The format of the glyph bitmap (monochrome or gray). */
/* */
/* max_grays :: Maximum gray level value (in the range 1 to~255). */
/* */
/* pitch :: The number of bytes per bitmap line. May be positive */
/* or negative. */
/* */
/* xadvance :: The horizontal advance width in pixels. */
/* */
/* yadvance :: The vertical advance height in pixels. */
/* */
/* buffer :: A pointer to the bitmap pixels. */
/* */
typedef struct FTC_SBitRec_
{
FT_Byte width;
FT_Byte height;
FT_Char left;
FT_Char top;
FT_Byte format;
FT_Byte max_grays;
FT_Short pitch;
FT_Char xadvance;
FT_Char yadvance;
FT_Byte* buffer;
} FTC_SBitRec;
/*************************************************************************/
/* */
/* <Type> */
/* FTC_SBitCache */
/* */
/* <Description> */
/* A handle to a small bitmap cache. These are special cache objects */
/* used to store small glyph bitmaps (and anti-aliased pixmaps) in a */
/* much more efficient way than the traditional glyph image cache */
/* implemented by @FTC_ImageCache. */
/* */
typedef struct FTC_SBitCacheRec_* FTC_SBitCache;
/*************************************************************************/
/* */
/* <Function> */
/* FTC_SBitCache_New */
/* */
/* <Description> */
/* Create a new cache to store small glyph bitmaps. */
/* */
/* <Input> */
/* manager :: A handle to the source cache manager. */
/* */
/* <Output> */
/* acache :: A handle to the new sbit cache. NULL in case of error. */
/* */
/* <Return> */
/* FreeType error code. 0~means success. */
/* */
FT_EXPORT( FT_Error )
FTC_SBitCache_New( FTC_Manager manager,
FTC_SBitCache *acache );
/*************************************************************************/
/* */
/* <Function> */
/* FTC_SBitCache_Lookup */
/* */
/* <Description> */
/* Look up a given small glyph bitmap in a given sbit cache and */
/* `lock' it to prevent its flushing from the cache until needed. */
/* */
/* <Input> */
/* cache :: A handle to the source sbit cache. */
/* */
/* type :: A pointer to the glyph image type descriptor. */
/* */
/* gindex :: The glyph index. */
/* */
/* <Output> */
/* sbit :: A handle to a small bitmap descriptor. */
/* */
/* anode :: Used to return the address of of the corresponding cache */
/* node after incrementing its reference count (see note */
/* below). */
/* */
/* <Return> */
/* FreeType error code. 0~means success. */
/* */
/* <Note> */
/* The small bitmap descriptor and its bit buffer are owned by the */
/* cache and should never be freed by the application. They might */
/* as well disappear from memory on the next cache lookup, so don't */
/* treat them as persistent data. */
/* */
/* The descriptor's `buffer' field is set to~0 to indicate a missing */
/* glyph bitmap. */
/* */
/* If `anode' is _not_ NULL, it receives the address of the cache */
/* node containing the bitmap, after increasing its reference count. */
/* This ensures that the node (as well as the image) will always be */
/* kept in the cache until you call @FTC_Node_Unref to `release' it. */
/* */
/* If `anode' is NULL, the cache node is left unchanged, which means */
/* that the bitmap could be flushed out of the cache on the next */
/* call to one of the caching sub-system APIs. Don't assume that it */
/* is persistent! */
/* */
FT_EXPORT( FT_Error )
FTC_SBitCache_Lookup( FTC_SBitCache cache,
FTC_ImageType type,
FT_UInt gindex,
FTC_SBit *sbit,
FTC_Node *anode );
/*************************************************************************/
/* */
/* <Function> */
/* FTC_SBitCache_LookupScaler */
/* */
/* <Description> */
/* A variant of @FTC_SBitCache_Lookup that uses an @FTC_ScalerRec */
/* to specify the face ID and its size. */
/* */
/* <Input> */
/* cache :: A handle to the source sbit cache. */
/* */
/* scaler :: A pointer to the scaler descriptor. */
/* */
/* load_flags :: The corresponding load flags. */
/* */
/* gindex :: The glyph index. */
/* */
/* <Output> */
/* sbit :: A handle to a small bitmap descriptor. */
/* */
/* anode :: Used to return the address of of the corresponding */
/* cache node after incrementing its reference count */
/* (see note below). */
/* */
/* <Return> */
/* FreeType error code. 0~means success. */
/* */
/* <Note> */
/* The small bitmap descriptor and its bit buffer are owned by the */
/* cache and should never be freed by the application. They might */
/* as well disappear from memory on the next cache lookup, so don't */
/* treat them as persistent data. */
/* */
/* The descriptor's `buffer' field is set to~0 to indicate a missing */
/* glyph bitmap. */
/* */
/* If `anode' is _not_ NULL, it receives the address of the cache */
/* node containing the bitmap, after increasing its reference count. */
/* This ensures that the node (as well as the image) will always be */
/* kept in the cache until you call @FTC_Node_Unref to `release' it. */
/* */
/* If `anode' is NULL, the cache node is left unchanged, which means */
/* that the bitmap could be flushed out of the cache on the next */
/* call to one of the caching sub-system APIs. Don't assume that it */
/* is persistent! */
/* */
FT_EXPORT( FT_Error )
FTC_SBitCache_LookupScaler( FTC_SBitCache cache,
FTC_Scaler scaler,
FT_ULong load_flags,
FT_UInt gindex,
FTC_SBit *sbit,
FTC_Node *anode );
/* */
FT_END_HEADER
#endif /* __FTCACHE_H__ */
/* END */
|