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/****************************************************************************
*
* ftotval.h
*
* FreeType API for validating OpenType tables (specification).
*
* Copyright (C) 2004-2020 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.
*
*/
/****************************************************************************
*
*
* Warning: This module might be moved to a different library in the
* future to avoid a tight dependency between FreeType and the
* OpenType specification.
*
*
*/
#ifndef FTOTVAL_H_
#define FTOTVAL_H_
#include <ft2build.h>
#include <freetype/freetype.h>
#ifdef FREETYPE_H
#error "freetype.h of FreeType 1 has been loaded!"
#error "Please fix the directory search order for header files"
#error "so that freetype.h of FreeType 2 is found first."
#endif
FT_BEGIN_HEADER
/**************************************************************************
*
* @section:
* ot_validation
*
* @title:
* OpenType Validation
*
* @abstract:
* An API to validate OpenType tables.
*
* @description:
* This section contains the declaration of functions to validate some
* OpenType tables (BASE, GDEF, GPOS, GSUB, JSTF, MATH).
*
* @order:
* FT_OpenType_Validate
* FT_OpenType_Free
*
* FT_VALIDATE_OTXXX
*
*/
/**************************************************************************
*
* @enum:
* FT_VALIDATE_OTXXX
*
* @description:
* A list of bit-field constants used with @FT_OpenType_Validate to
* indicate which OpenType tables should be validated.
*
* @values:
* FT_VALIDATE_BASE ::
* Validate BASE table.
*
* FT_VALIDATE_GDEF ::
* Validate GDEF table.
*
* FT_VALIDATE_GPOS ::
* Validate GPOS table.
*
* FT_VALIDATE_GSUB ::
* Validate GSUB table.
*
* FT_VALIDATE_JSTF ::
* Validate JSTF table.
*
* FT_VALIDATE_MATH ::
* Validate MATH table.
*
* FT_VALIDATE_OT ::
* Validate all OpenType tables (BASE, GDEF, GPOS, GSUB, JSTF, MATH).
*
*/
#define FT_VALIDATE_BASE 0x0100
#define FT_VALIDATE_GDEF 0x0200
#define FT_VALIDATE_GPOS 0x0400
#define FT_VALIDATE_GSUB 0x0800
#define FT_VALIDATE_JSTF 0x1000
#define FT_VALIDATE_MATH 0x2000
#define FT_VALIDATE_OT ( FT_VALIDATE_BASE | \
FT_VALIDATE_GDEF | \
FT_VALIDATE_GPOS | \
FT_VALIDATE_GSUB | \
FT_VALIDATE_JSTF | \
FT_VALIDATE_MATH )
/**************************************************************************
*
* @function:
* FT_OpenType_Validate
*
* @description:
* Validate various OpenType tables to assure that all offsets and
* indices are valid. The idea is that a higher-level library that
* actually does the text layout can access those tables without error
* checking (which can be quite time consuming).
*
* @input:
* face ::
* A handle to the input face.
*
* validation_flags ::
* A bit field that specifies the tables to be validated. See
* @FT_VALIDATE_OTXXX for possible values.
*
* @output:
* BASE_table ::
* A pointer to the BASE table.
*
* GDEF_table ::
* A pointer to the GDEF table.
*
* GPOS_table ::
* A pointer to the GPOS table.
*
* GSUB_table ::
* A pointer to the GSUB table.
*
* JSTF_table ::
* A pointer to the JSTF table.
*
* @return:
* FreeType error code. 0~means success.
*
* @note:
* This function only works with OpenType fonts, returning an error
* otherwise.
*
* After use, the application should deallocate the five tables with
* @FT_OpenType_Free. A `NULL` value indicates that the table either
* doesn't exist in the font, or the application hasn't asked for
* validation.
*/
FT_EXPORT( FT_Error )
FT_OpenType_Validate( FT_Face face,
FT_UInt validation_flags,
FT_Bytes *BASE_table,
FT_Bytes *GDEF_table,
FT_Bytes *GPOS_table,
FT_Bytes *GSUB_table,
FT_Bytes *JSTF_table );
/**************************************************************************
*
* @function:
* FT_OpenType_Free
*
* @description:
* Free the buffer allocated by OpenType validator.
*
* @input:
* face ::
* A handle to the input face.
*
* table ::
* The pointer to the buffer that is allocated by
* @FT_OpenType_Validate.
*
* @note:
* This function must be used to free the buffer allocated by
* @FT_OpenType_Validate only.
*/
FT_EXPORT( void )
FT_OpenType_Free( FT_Face face,
FT_Bytes table );
/* */
FT_END_HEADER
#endif /* FTOTVAL_H_ */
/* END */