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Diffstat (limited to 'modules/freetype2/include/freetype/ftsystem.h')
| -rw-r--r-- | modules/freetype2/include/freetype/ftsystem.h | 358 |
1 files changed, 358 insertions, 0 deletions
diff --git a/modules/freetype2/include/freetype/ftsystem.h b/modules/freetype2/include/freetype/ftsystem.h new file mode 100644 index 0000000000..a995b078de --- /dev/null +++ b/modules/freetype2/include/freetype/ftsystem.h @@ -0,0 +1,358 @@ +/**************************************************************************** + * + * ftsystem.h + * + * FreeType low-level system interface definition (specification). + * + * Copyright (C) 1996-2023 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 from the start of the stream to seek to if this is a seek + * operation (see note). + * + * 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 performs a seek *or* a read operation depending on the + * argument values. If `count` is zero, the operation is a seek to + * `offset` bytes. If `count` is >~0, the operation is a read of `count` + * bytes from the current position in the stream, and the `offset` value + * should be ignored. + * + * For seek operations, a non-zero return value 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 */ |