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Diffstat (limited to 'freetype/include/ftsystem.h')
| -rw-r--r-- | freetype/include/ftsystem.h | 347 |
1 files changed, 347 insertions, 0 deletions
diff --git a/freetype/include/ftsystem.h b/freetype/include/ftsystem.h new file mode 100644 index 000000000..e07460c55 --- /dev/null +++ b/freetype/include/ftsystem.h @@ -0,0 +1,347 @@ +/***************************************************************************/ +/* */ +/* ftsystem.h */ +/* */ +/* FreeType low-level system interface definition (specification). */ +/* */ +/* Copyright 1996-2001, 2002, 2005, 2010 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 */ + /* 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 an + * @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. A non-zero return value then indicates an + * error. + * + */ + 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 */ |