| /**************************************************************************** |
| * |
| * ftsystem.h |
| * |
| * FreeType low-level system interface definition (specification). |
| * |
| * Copyright (C) 1996-2022 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_ |
| |
| |
| |
| |
| 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. |
| * |
| * @also: |
| * See @FT_StreamRec for the publicly accessible fields of a given stream |
| * object. |
| * |
| */ |
| 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. |
| * |
| * In case of compressed streams where the size is unknown before |
| * actually doing the decompression, the value is set to 0x7FFFFFFF. |
| * (Note that this size value can occur for normal streams also; it is |
| * thus just a hint.) |
| * |
| * 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. In particular, the `FT_GET_XXX` macros use this instead of |
| * the `pos` field. |
| * |
| * 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 */ |