ftdriver.h revision ec0bab5697bb31ba980810145f62e3799946ec60
1/***************************************************************************/ 2/* */ 3/* ftdriver.h */ 4/* */ 5/* FreeType font driver interface (specification). */ 6/* */ 7/* Copyright 1996-2003, 2006, 2008, 2011-2013 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#ifndef __FTDRIVER_H__ 20#define __FTDRIVER_H__ 21 22 23#include <ft2build.h> 24#include FT_MODULE_H 25 26 27FT_BEGIN_HEADER 28 29 30 typedef FT_Error 31 (*FT_Face_InitFunc)( FT_Stream stream, 32 FT_Face face, 33 FT_Int typeface_index, 34 FT_Int num_params, 35 FT_Parameter* parameters ); 36 37 typedef void 38 (*FT_Face_DoneFunc)( FT_Face face ); 39 40 41 typedef FT_Error 42 (*FT_Size_InitFunc)( FT_Size size ); 43 44 typedef void 45 (*FT_Size_DoneFunc)( FT_Size size ); 46 47 48 typedef FT_Error 49 (*FT_Slot_InitFunc)( FT_GlyphSlot slot ); 50 51 typedef void 52 (*FT_Slot_DoneFunc)( FT_GlyphSlot slot ); 53 54 55 typedef FT_Error 56 (*FT_Size_RequestFunc)( FT_Size size, 57 FT_Size_Request req ); 58 59 typedef FT_Error 60 (*FT_Size_SelectFunc)( FT_Size size, 61 FT_ULong size_index ); 62 63 typedef FT_Error 64 (*FT_Slot_LoadFunc)( FT_GlyphSlot slot, 65 FT_Size size, 66 FT_UInt glyph_index, 67 FT_Int32 load_flags ); 68 69 70 typedef FT_UInt 71 (*FT_CharMap_CharIndexFunc)( FT_CharMap charmap, 72 FT_Long charcode ); 73 74 typedef FT_Long 75 (*FT_CharMap_CharNextFunc)( FT_CharMap charmap, 76 FT_Long charcode ); 77 78 79 typedef FT_Error 80 (*FT_Face_GetKerningFunc)( FT_Face face, 81 FT_UInt left_glyph, 82 FT_UInt right_glyph, 83 FT_Vector* kerning ); 84 85 86 typedef FT_Error 87 (*FT_Face_AttachFunc)( FT_Face face, 88 FT_Stream stream ); 89 90 91 typedef FT_Error 92 (*FT_Face_GetAdvancesFunc)( FT_Face face, 93 FT_UInt first, 94 FT_UInt count, 95 FT_Int32 flags, 96 FT_Fixed* advances ); 97 98 99 /*************************************************************************/ 100 /* */ 101 /* <Struct> */ 102 /* FT_Driver_ClassRec */ 103 /* */ 104 /* <Description> */ 105 /* The font driver class. This structure mostly contains pointers to */ 106 /* driver methods. */ 107 /* */ 108 /* <Fields> */ 109 /* root :: The parent module. */ 110 /* */ 111 /* face_object_size :: The size of a face object in bytes. */ 112 /* */ 113 /* size_object_size :: The size of a size object in bytes. */ 114 /* */ 115 /* slot_object_size :: The size of a glyph object in bytes. */ 116 /* */ 117 /* init_face :: The format-specific face constructor. */ 118 /* */ 119 /* done_face :: The format-specific face destructor. */ 120 /* */ 121 /* init_size :: The format-specific size constructor. */ 122 /* */ 123 /* done_size :: The format-specific size destructor. */ 124 /* */ 125 /* init_slot :: The format-specific slot constructor. */ 126 /* */ 127 /* done_slot :: The format-specific slot destructor. */ 128 /* */ 129 /* */ 130 /* load_glyph :: A function handle to load a glyph to a slot. */ 131 /* This field is mandatory! */ 132 /* */ 133 /* get_kerning :: A function handle to return the unscaled */ 134 /* kerning for a given pair of glyphs. Can be */ 135 /* set to 0 if the format doesn't support */ 136 /* kerning. */ 137 /* */ 138 /* attach_file :: This function handle is used to read */ 139 /* additional data for a face from another */ 140 /* file/stream. For example, this can be used to */ 141 /* add data from AFM or PFM files on a Type 1 */ 142 /* face, or a CIDMap on a CID-keyed face. */ 143 /* */ 144 /* get_advances :: A function handle used to return advance */ 145 /* widths of `count' glyphs (in font units), */ 146 /* starting at `first'. The `vertical' flag must */ 147 /* be set to get vertical advance heights. The */ 148 /* `advances' buffer is caller-allocated. */ 149 /* The idea of this function is to be able to */ 150 /* perform device-independent text layout without */ 151 /* loading a single glyph image. */ 152 /* */ 153 /* request_size :: A handle to a function used to request the new */ 154 /* character size. Can be set to 0 if the */ 155 /* scaling done in the base layer suffices. */ 156 /* */ 157 /* select_size :: A handle to a function used to select a new */ 158 /* fixed size. It is used only if */ 159 /* @FT_FACE_FLAG_FIXED_SIZES is set. Can be set */ 160 /* to 0 if the scaling done in the base layer */ 161 /* suffices. */ 162 /* <Note> */ 163 /* Most function pointers, with the exception of `load_glyph', can be */ 164 /* set to 0 to indicate a default behaviour. */ 165 /* */ 166 typedef struct FT_Driver_ClassRec_ 167 { 168 FT_Module_Class root; 169 170 FT_Long face_object_size; 171 FT_Long size_object_size; 172 FT_Long slot_object_size; 173 174 FT_Face_InitFunc init_face; 175 FT_Face_DoneFunc done_face; 176 177 FT_Size_InitFunc init_size; 178 FT_Size_DoneFunc done_size; 179 180 FT_Slot_InitFunc init_slot; 181 FT_Slot_DoneFunc done_slot; 182 183 FT_Slot_LoadFunc load_glyph; 184 185 FT_Face_GetKerningFunc get_kerning; 186 FT_Face_AttachFunc attach_file; 187 FT_Face_GetAdvancesFunc get_advances; 188 189 /* since version 2.2 */ 190 FT_Size_RequestFunc request_size; 191 FT_Size_SelectFunc select_size; 192 193 } FT_Driver_ClassRec, *FT_Driver_Class; 194 195 196 /*************************************************************************/ 197 /* */ 198 /* <Macro> */ 199 /* FT_DECLARE_DRIVER */ 200 /* */ 201 /* <Description> */ 202 /* Used to create a forward declaration of an FT_Driver_ClassRec */ 203 /* struct instance. */ 204 /* */ 205 /* <Macro> */ 206 /* FT_DEFINE_DRIVER */ 207 /* */ 208 /* <Description> */ 209 /* Used to initialize an instance of FT_Driver_ClassRec struct. */ 210 /* */ 211 /* When FT_CONFIG_OPTION_PIC is defined a `create' function has to be */ 212 /* called with a pointer where the allocated structure is returned. */ 213 /* And when it is no longer needed a `destroy' function needs to be */ 214 /* called to release that allocation. */ 215 /* */ 216 /* `fcinit.c' (ft_create_default_module_classes) already contains a */ 217 /* mechanism to call these functions for the default modules */ 218 /* described in `ftmodule.h'. */ 219 /* */ 220 /* Notice that the created `create' and `destroy' functions call */ 221 /* `pic_init' and `pic_free' to allow you to manually allocate and */ 222 /* initialize any additional global data, like a module specific */ 223 /* interface, and put them in the global pic container defined in */ 224 /* `ftpic.h'. If you don't need them just implement the functions as */ 225 /* empty to resolve the link error. Also the `pic_init' and */ 226 /* `pic_free' functions should be declared in `pic.h', to be referred */ 227 /* by driver definition calling `FT_DEFINE_DRIVER' in following. */ 228 /* */ 229 /* When FT_CONFIG_OPTION_PIC is not defined the struct will be */ 230 /* allocated in the global scope (or the scope where the macro is */ 231 /* used). */ 232 /* */ 233#ifndef FT_CONFIG_OPTION_PIC 234 235#define FT_DECLARE_DRIVER( class_ ) \ 236 FT_CALLBACK_TABLE \ 237 const FT_Driver_ClassRec class_; 238 239#define FT_DEFINE_DRIVER( \ 240 class_, \ 241 flags_, \ 242 size_, \ 243 name_, \ 244 version_, \ 245 requires_, \ 246 interface_, \ 247 init_, \ 248 done_, \ 249 get_interface_, \ 250 face_object_size_, \ 251 size_object_size_, \ 252 slot_object_size_, \ 253 init_face_, \ 254 done_face_, \ 255 init_size_, \ 256 done_size_, \ 257 init_slot_, \ 258 done_slot_, \ 259 load_glyph_, \ 260 get_kerning_, \ 261 attach_file_, \ 262 get_advances_, \ 263 request_size_, \ 264 select_size_ ) \ 265 FT_CALLBACK_TABLE_DEF \ 266 const FT_Driver_ClassRec class_ = \ 267 { \ 268 FT_DEFINE_ROOT_MODULE( flags_, \ 269 size_, \ 270 name_, \ 271 version_, \ 272 requires_, \ 273 interface_, \ 274 init_, \ 275 done_, \ 276 get_interface_ ) \ 277 \ 278 face_object_size_, \ 279 size_object_size_, \ 280 slot_object_size_, \ 281 \ 282 init_face_, \ 283 done_face_, \ 284 \ 285 init_size_, \ 286 done_size_, \ 287 \ 288 init_slot_, \ 289 done_slot_, \ 290 \ 291 load_glyph_, \ 292 \ 293 get_kerning_, \ 294 attach_file_, \ 295 get_advances_, \ 296 \ 297 request_size_, \ 298 select_size_ \ 299 }; 300 301#else /* FT_CONFIG_OPTION_PIC */ 302 303#define FT_DECLARE_DRIVER( class_ ) FT_DECLARE_MODULE( class_ ) 304 305#define FT_DEFINE_DRIVER( \ 306 class_, \ 307 flags_, \ 308 size_, \ 309 name_, \ 310 version_, \ 311 requires_, \ 312 interface_, \ 313 init_, \ 314 done_, \ 315 get_interface_, \ 316 face_object_size_, \ 317 size_object_size_, \ 318 slot_object_size_, \ 319 init_face_, \ 320 done_face_, \ 321 init_size_, \ 322 done_size_, \ 323 init_slot_, \ 324 done_slot_, \ 325 load_glyph_, \ 326 get_kerning_, \ 327 attach_file_, \ 328 get_advances_, \ 329 request_size_, \ 330 select_size_ ) \ 331 void \ 332 FT_Destroy_Class_ ## class_( FT_Library library, \ 333 FT_Module_Class* clazz ) \ 334 { \ 335 FT_Memory memory = library->memory; \ 336 FT_Driver_Class dclazz = (FT_Driver_Class)clazz; \ 337 \ 338 \ 339 class_ ## _pic_free( library ); \ 340 if ( dclazz ) \ 341 FT_FREE( dclazz ); \ 342 } \ 343 \ 344 \ 345 FT_Error \ 346 FT_Create_Class_ ## class_( FT_Library library, \ 347 FT_Module_Class** output_class ) \ 348 { \ 349 FT_Driver_Class clazz = NULL; \ 350 FT_Error error; \ 351 FT_Memory memory = library->memory; \ 352 \ 353 \ 354 if ( FT_ALLOC( clazz, sizeof ( *clazz ) ) ) \ 355 return error; \ 356 \ 357 error = class_ ## _pic_init( library ); \ 358 if ( error ) \ 359 { \ 360 FT_FREE( clazz ); \ 361 return error; \ 362 } \ 363 \ 364 FT_DEFINE_ROOT_MODULE( flags_, \ 365 size_, \ 366 name_, \ 367 version_, \ 368 requires_, \ 369 interface_, \ 370 init_, \ 371 done_, \ 372 get_interface_ ) \ 373 \ 374 clazz->face_object_size = face_object_size_; \ 375 clazz->size_object_size = size_object_size_; \ 376 clazz->slot_object_size = slot_object_size_; \ 377 \ 378 clazz->init_face = init_face_; \ 379 clazz->done_face = done_face_; \ 380 \ 381 clazz->init_size = init_size_; \ 382 clazz->done_size = done_size_; \ 383 \ 384 clazz->init_slot = init_slot_; \ 385 clazz->done_slot = done_slot_; \ 386 \ 387 clazz->load_glyph = load_glyph_; \ 388 \ 389 clazz->get_kerning = get_kerning_; \ 390 clazz->attach_file = attach_file_; \ 391 clazz->get_advances = get_advances_; \ 392 \ 393 clazz->request_size = request_size_; \ 394 clazz->select_size = select_size_; \ 395 \ 396 *output_class = (FT_Module_Class*)clazz; \ 397 \ 398 return FT_Err_Ok; \ 399 } 400 401 402#endif /* FT_CONFIG_OPTION_PIC */ 403 404FT_END_HEADER 405 406#endif /* __FTDRIVER_H__ */ 407 408 409/* END */ 410