ref: 76b565d8b219c8db94a882e93725b4ab735414de
dir: /include/freetype/ftsystem.h/
/***************************************************************************/
/* */
/* 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 */