/***************************************************************************//* *//* ftsystem.h *//* *//* FreeType low-level system interface definition (specification). *//* *//* Copyright 1996-2001, 2002 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 __FTSYSTEM_H__#define __FTSYSTEM_H__ #include <ft2build.h> FT_BEGIN_HEADER /*************************************************************************/ /* */ /* <Section> */ /* system_interface */ /* */ /* <Title> */ /* System Interface */ /* */ /* <Abstract> */ /* How FreeType manages memory and i/o. */ /* */ /* <Description> */ /* This section contains various definitions related to memory */ /* management and i/o access. You need to understand this */ /* information if you want to use a custom memory manager or you own */ /* input i/o streams. */ /* */ /*************************************************************************/ /*************************************************************************/ /* */ /* M E M O R Y M A N A G E M E N T */ /* */ /*************************************************************************/ /*************************************************************************/ /* */ /* @type: */ /* FT_Memory */ /* */ /* @description: */ /* A handle to a given memory manager object, defined with a */ /* @FT_MemoryRec structure. */ /* */ typedef struct FT_MemoryRec_* FT_Memory; /*************************************************************************/ /* */ /* @functype: */ /* FT_Alloc_Func */ /* */ /* @description: */ /* A function used to allocate `size' bytes from `memory'. */ /* */ /* @input: */ /* memory :: A handle to the source memory manager. */ /* */ /* size :: The size in bytes to allocate. */ /* */ /* @return: */ /* Address of new memory block. 0 in case of failure. */ /* */ typedef void* (*FT_Alloc_Func)( FT_Memory memory, long size ); /*************************************************************************/ /* */ /* @functype: */ /* FT_Free_Func */ /* */ /* @description: */ /* A function used to release a given block of memory. */ /* */ /* @input: */ /* memory :: A handle to the source memory manager. */ /* */ /* block :: The address of the target memory block. */ /* */ typedef void (*FT_Free_Func)( FT_Memory memory, void* block ); /*************************************************************************/ /* */ /* @functype: */ /* FT_Realloc_Func */ /* */ /* @description: */ /* a function used to re-allocate a given block of memory. */ /* */ /* @input: */ /* memory :: A handle to the source memory manager. */ /* */ /* cur_size :: The block's current size in bytes. */ /* */ /* new_size :: The block's requested new size. */ /* */ /* block :: The block's current address. */ /* */ /* @return: */ /* New block address. 0 in case of memory shortage. */ /* */ /* @note: */ /* In case of error, the old block must still be available. */ /* */ typedef void* (*FT_Realloc_Func)( FT_Memory memory, long cur_size, long new_size, void* block ); /*************************************************************************/ /* */ /* @struct: */ /* FT_MemoryRec */ /* */ /* @description: */ /* A structure used to describe a given memory manager to FreeType 2. */ /* */ /* @fields: */ /* user :: A generic typeless pointer for user data. */ /* */ /* alloc :: A pointer type to an allocation function. */ /* */ /* free :: A pointer type to an memory freeing function. */ /* */ /* realloc :: A pointer type to a reallocation function. */ /* */ struct FT_MemoryRec_ { void* user; FT_Alloc_Func alloc; FT_Free_Func free; FT_Realloc_Func realloc; }; /*************************************************************************/ /* */ /* I / O M A N A G E M E N T */ /* */ /*************************************************************************/ /*************************************************************************/ /* */ /* @type: */ /* FT_Stream */ /* */ /* @description: */ /* A handle to an input stream. */ /* */ typedef struct FT_StreamRec_* FT_Stream; /*************************************************************************/ /* */ /* @struct: */ /* FT_StreamDesc */ /* */ /* @description: */ /* A union type used to store either a long or a pointer. This is */ /* used to store a file descriptor or a FILE* in an input stream. */ /* */ typedef union FT_StreamDesc_ { long value; void* pointer; } FT_StreamDesc; /*************************************************************************/ /* */ /* @functype: */ /* FT_Stream_IoFunc */ /* */ /* @description: */ /* A function used to seek and read data from a given input stream. */ /* */ /* @input: */ /* stream :: A handle to the source stream. */ /* */ /* offset :: The offset of read in stream (always from start). */ /* */ /* buffer :: The address of the read buffer. */ /* */ /* count :: The number of bytes to read from the stream. */ /* */ /* @return: */ /* The number of bytes effectively read by the stream. */ /* */ /* @note: */ /* This function might be called to perform a seek or skip operation */ /* with a `count' of 0. */ /* */ typedef unsigned long (*FT_Stream_IoFunc)( FT_Stream stream, unsigned long offset, unsigned char* buffer, unsigned long count ); /*************************************************************************/ /* */ /* @functype: */ /* FT_Stream_CloseFunc */ /* */ /* @description: */ /* A function used to close a given input stream. */ /* */ /* @input: */ /* stream :: A handle to the target stream. */ /* */ typedef void (*FT_Stream_CloseFunc)( FT_Stream stream ); /*************************************************************************/ /* */ /* @struct: */ /* FT_StreamRec */ /* */ /* @description: */ /* A structure used to describe an input stream. */ /* */ /* @input: */ /* base :: For memory-based streams, this is the address of the */ /* first stream byte in memory. This field should */ /* always be set to NULL for disk-based streams. */ /* */ /* size :: The stream size in bytes. */ /* */ /* pos :: The current position within the stream. */ /* */ /* descriptor :: This field is a union that can hold an integer or a */ /* pointer. It is used by stream implementations to */ /* store file descriptors or FILE* pointers. */ /* */ /* pathname :: This field is completely ignored by FreeType. */ /* However, it is often useful during debugging to use */ /* it to store the stream's filename (where available). */ /* */ /* read :: The stream's input function. */ /* */ /* close :: The stream;s close function. */ /* */ /* memory :: The memory manager to use to preload frames. This is */ /* set internally by FreeType and shouldn't be touched */ /* by stream implementations. */ /* */ /* cursor :: This field is set and used internally by FreeType */ /* when parsing frames. */ /* */ /* limit :: This field is set and used internally by FreeType */ /* when parsing frames. */ /* */ typedef struct FT_StreamRec_ { unsigned char* base; unsigned long size; unsigned long pos; FT_StreamDesc descriptor; FT_StreamDesc pathname; FT_Stream_IoFunc read; FT_Stream_CloseFunc close; FT_Memory memory; unsigned char* cursor; unsigned char* limit; } FT_StreamRec; /* */ FT_END_HEADER #endif /* __FTSYSTEM_H__ */ /* END */