1 /***************************************************************************/ 2 /* */ 3 /* ftsystem.h */ 4 /* */ 5 /* FreeType low-level system interface definition (specification). */ 6 /* */ 7 /* Copyright 1996-2001, 2002, 2005, 2010 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 __FTSYSTEM_H__ 20 #define __FTSYSTEM_H__ 21 22 23 #include "../ft2build.h" 24 25 26 FT_BEGIN_HEADER 27 28 29 /*************************************************************************/ 30 /* */ 31 /* <Section> */ 32 /* system_interface */ 33 /* */ 34 /* <Title> */ 35 /* System Interface */ 36 /* */ 37 /* <Abstract> */ 38 /* How FreeType manages memory and i/o. */ 39 /* */ 40 /* <Description> */ 41 /* This section contains various definitions related to memory */ 42 /* management and i/o access. You need to understand this */ 43 /* information if you want to use a custom memory manager or you own */ 44 /* i/o streams. */ 45 /* */ 46 /*************************************************************************/ 47 48 49 /*************************************************************************/ 50 /* */ 51 /* M E M O R Y M A N A G E M E N T */ 52 /* */ 53 /*************************************************************************/ 54 55 56 /************************************************************************* 57 * 58 * @type: 59 * FT_Memory 60 * 61 * @description: 62 * A handle to a given memory manager object, defined with an 63 * @FT_MemoryRec structure. 64 * 65 */ 66 typedef struct FT_MemoryRec_* FT_Memory; 67 68 69 /************************************************************************* 70 * 71 * @functype: 72 * FT_Alloc_Func 73 * 74 * @description: 75 * A function used to allocate `size' bytes from `memory'. 76 * 77 * @input: 78 * memory :: 79 * A handle to the source memory manager. 80 * 81 * size :: 82 * The size in bytes to allocate. 83 * 84 * @return: 85 * Address of new memory block. 0~in case of failure. 86 * 87 */ 88 typedef void* 89 (*FT_Alloc_Func)( FT_Memory memory, 90 long size ); 91 92 /* Sunliang.Liu 20100915 sync 221's revison. */ 93 typedef void* 94 (*FT_AllocDebug_Func)( FT_Memory memory, 95 long size, const char* filename, int line); 96 97 98 99 /************************************************************************* 100 * 101 * @functype: 102 * FT_Free_Func 103 * 104 * @description: 105 * A function used to release a given block of memory. 106 * 107 * @input: 108 * memory :: 109 * A handle to the source memory manager. 110 * 111 * block :: 112 * The address of the target memory block. 113 * 114 */ 115 typedef void 116 (*FT_Free_Func)( FT_Memory memory, 117 void* block ); 118 119 120 /************************************************************************* 121 * 122 * @functype: 123 * FT_Realloc_Func 124 * 125 * @description: 126 * A function used to re-allocate a given block of memory. 127 * 128 * @input: 129 * memory :: 130 * A handle to the source memory manager. 131 * 132 * cur_size :: 133 * The block's current size in bytes. 134 * 135 * new_size :: 136 * The block's requested new size. 137 * 138 * block :: 139 * The block's current address. 140 * 141 * @return: 142 * New block address. 0~in case of memory shortage. 143 * 144 * @note: 145 * In case of error, the old block must still be available. 146 * 147 */ 148 typedef void* 149 (*FT_Realloc_Func)( FT_Memory memory, 150 long cur_size, 151 long new_size, 152 void* block ); 153 154 155 /************************************************************************* 156 * 157 * @struct: 158 * FT_MemoryRec 159 * 160 * @description: 161 * A structure used to describe a given memory manager to FreeType~2. 162 * 163 * @fields: 164 * user :: 165 * A generic typeless pointer for user data. 166 * 167 * alloc :: 168 * A pointer type to an allocation function. 169 * 170 * free :: 171 * A pointer type to an memory freeing function. 172 * 173 * realloc :: 174 * A pointer type to a reallocation function. 175 * 176 */ 177 struct FT_MemoryRec_ 178 { 179 void* user; 180 FT_Alloc_Func alloc; 181 FT_AllocDebug_Func allocdebug; /* Sunliang.Liu 20100915 sync 221's revison. */ 182 FT_Free_Func free; 183 FT_Realloc_Func realloc; 184 }; 185 186 187 /*************************************************************************/ 188 /* */ 189 /* I / O M A N A G E M E N T */ 190 /* */ 191 /*************************************************************************/ 192 193 194 /************************************************************************* 195 * 196 * @type: 197 * FT_Stream 198 * 199 * @description: 200 * A handle to an input stream. 201 * 202 */ 203 typedef struct FT_StreamRec_* FT_Stream; 204 205 206 /************************************************************************* 207 * 208 * @struct: 209 * FT_StreamDesc 210 * 211 * @description: 212 * A union type used to store either a long or a pointer. This is used 213 * to store a file descriptor or a `FILE*' in an input stream. 214 * 215 */ 216 typedef union FT_StreamDesc_ 217 { 218 long value; 219 void* pointer; 220 221 } FT_StreamDesc; 222 223 224 /************************************************************************* 225 * 226 * @functype: 227 * FT_Stream_IoFunc 228 * 229 * @description: 230 * A function used to seek and read data from a given input stream. 231 * 232 * @input: 233 * stream :: 234 * A handle to the source stream. 235 * 236 * offset :: 237 * The offset of read in stream (always from start). 238 * 239 * buffer :: 240 * The address of the read buffer. 241 * 242 * count :: 243 * The number of bytes to read from the stream. 244 * 245 * @return: 246 * The number of bytes effectively read by the stream. 247 * 248 * @note: 249 * This function might be called to perform a seek or skip operation 250 * with a `count' of~0. A non-zero return value then indicates an 251 * error. 252 * 253 */ 254 typedef unsigned long 255 (*FT_Stream_IoFunc)( FT_Stream stream, 256 unsigned long offset, 257 unsigned char* buffer, 258 unsigned long count ); 259 260 261 /************************************************************************* 262 * 263 * @functype: 264 * FT_Stream_CloseFunc 265 * 266 * @description: 267 * A function used to close a given input stream. 268 * 269 * @input: 270 * stream :: 271 * A handle to the target stream. 272 * 273 */ 274 typedef void 275 (*FT_Stream_CloseFunc)( FT_Stream stream ); 276 277 278 /************************************************************************* 279 * 280 * @struct: 281 * FT_StreamRec 282 * 283 * @description: 284 * A structure used to describe an input stream. 285 * 286 * @input: 287 * base :: 288 * For memory-based streams, this is the address of the first stream 289 * byte in memory. This field should always be set to NULL for 290 * disk-based streams. 291 * 292 * size :: 293 * The stream size in bytes. 294 * 295 * pos :: 296 * The current position within the stream. 297 * 298 * descriptor :: 299 * This field is a union that can hold an integer or a pointer. It is 300 * used by stream implementations to store file descriptors or `FILE*' 301 * pointers. 302 * 303 * pathname :: 304 * This field is completely ignored by FreeType. However, it is often 305 * useful during debugging to use it to store the stream's filename 306 * (where available). 307 * 308 * read :: 309 * The stream's input function. 310 * 311 * close :: 312 * The stream's close function. 313 * 314 * memory :: 315 * The memory manager to use to preload frames. This is set 316 * internally by FreeType and shouldn't be touched by stream 317 * implementations. 318 * 319 * cursor :: 320 * This field is set and used internally by FreeType when parsing 321 * frames. 322 * 323 * limit :: 324 * This field is set and used internally by FreeType when parsing 325 * frames. 326 * 327 */ 328 typedef struct FT_StreamRec_ 329 { 330 unsigned char* base; 331 unsigned long size; 332 unsigned long pos; 333 334 FT_StreamDesc descriptor; 335 FT_StreamDesc pathname; 336 FT_Stream_IoFunc read; 337 FT_Stream_CloseFunc close; 338 339 FT_Memory memory; 340 unsigned char* cursor; 341 unsigned char* limit; 342 343 } FT_StreamRec; 344 345 346 /* */ 347 348 349 FT_END_HEADER 350 351 #endif /* __FTSYSTEM_H__ */ 352 353 354 /* END */ 355
