ref: 685acc04dbad5ece9b7261d21f4a2546d787436c
dir: /include/freetype/ftgxval.h/
/****************************************************************************
*
* ftgxval.h
*
* FreeType API for validating TrueTypeGX/AAT tables (specification).
*
* Copyright (C) 2004-2021 by
* Masatake YAMATO, Redhat K.K,
* 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.
*
*/
/****************************************************************************
*
* gxvalid is derived from both gxlayout module and otvalid module.
* Development of gxlayout is supported by the Information-technology
* Promotion Agency(IPA), Japan.
*
*/
#ifndef FTGXVAL_H_
#define FTGXVAL_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:
* gx_validation
*
* @title:
* TrueTypeGX/AAT Validation
*
* @abstract:
* An API to validate TrueTypeGX/AAT tables.
*
* @description:
* This section contains the declaration of functions to validate some
* TrueTypeGX tables (feat, mort, morx, bsln, just, kern, opbd, trak,
* prop, lcar).
*
* @order:
* FT_TrueTypeGX_Validate
* FT_TrueTypeGX_Free
*
* FT_ClassicKern_Validate
* FT_ClassicKern_Free
*
* FT_VALIDATE_GX_LENGTH
* FT_VALIDATE_GXXXX
* FT_VALIDATE_CKERNXXX
*
*/
/**************************************************************************
*
*
* Warning: Use `FT_VALIDATE_XXX` to validate a table.
* Following definitions are for gxvalid developers.
*
*
*/
#define FT_VALIDATE_feat_INDEX 0
#define FT_VALIDATE_mort_INDEX 1
#define FT_VALIDATE_morx_INDEX 2
#define FT_VALIDATE_bsln_INDEX 3
#define FT_VALIDATE_just_INDEX 4
#define FT_VALIDATE_kern_INDEX 5
#define FT_VALIDATE_opbd_INDEX 6
#define FT_VALIDATE_trak_INDEX 7
#define FT_VALIDATE_prop_INDEX 8
#define FT_VALIDATE_lcar_INDEX 9
#define FT_VALIDATE_GX_LAST_INDEX FT_VALIDATE_lcar_INDEX
/**************************************************************************
*
* @macro:
* FT_VALIDATE_GX_LENGTH
*
* @description:
* The number of tables checked in this module. Use it as a parameter
* for the `table-length` argument of function @FT_TrueTypeGX_Validate.
*/
#define FT_VALIDATE_GX_LENGTH ( FT_VALIDATE_GX_LAST_INDEX + 1 )
/* */
/* Up to 0x1000 is used by otvalid.
Ox2xxx is reserved for feature OT extension. */
#define FT_VALIDATE_GX_START 0x4000
#define FT_VALIDATE_GX_BITFIELD( tag ) \
( FT_VALIDATE_GX_START << FT_VALIDATE_##tag##_INDEX )
/**************************************************************************
*
* @enum:
* FT_VALIDATE_GXXXX
*
* @description:
* A list of bit-field constants used with @FT_TrueTypeGX_Validate to
* indicate which TrueTypeGX/AAT Type tables should be validated.
*
* @values:
* FT_VALIDATE_feat ::
* Validate 'feat' table.
*
* FT_VALIDATE_mort ::
* Validate 'mort' table.
*
* FT_VALIDATE_morx ::
* Validate 'morx' table.
*
* FT_VALIDATE_bsln ::
* Validate 'bsln' table.
*
* FT_VALIDATE_just ::
* Validate 'just' table.
*
* FT_VALIDATE_kern ::
* Validate 'kern' table.
*
* FT_VALIDATE_opbd ::
* Validate 'opbd' table.
*
* FT_VALIDATE_trak ::
* Validate 'trak' table.
*
* FT_VALIDATE_prop ::
* Validate 'prop' table.
*
* FT_VALIDATE_lcar ::
* Validate 'lcar' table.
*
* FT_VALIDATE_GX ::
* Validate all TrueTypeGX tables (feat, mort, morx, bsln, just, kern,
* opbd, trak, prop and lcar).
*
*/
#define FT_VALIDATE_feat FT_VALIDATE_GX_BITFIELD( feat )
#define FT_VALIDATE_mort FT_VALIDATE_GX_BITFIELD( mort )
#define FT_VALIDATE_morx FT_VALIDATE_GX_BITFIELD( morx )
#define FT_VALIDATE_bsln FT_VALIDATE_GX_BITFIELD( bsln )
#define FT_VALIDATE_just FT_VALIDATE_GX_BITFIELD( just )
#define FT_VALIDATE_kern FT_VALIDATE_GX_BITFIELD( kern )
#define FT_VALIDATE_opbd FT_VALIDATE_GX_BITFIELD( opbd )
#define FT_VALIDATE_trak FT_VALIDATE_GX_BITFIELD( trak )
#define FT_VALIDATE_prop FT_VALIDATE_GX_BITFIELD( prop )
#define FT_VALIDATE_lcar FT_VALIDATE_GX_BITFIELD( lcar )
#define FT_VALIDATE_GX ( FT_VALIDATE_feat | \
FT_VALIDATE_mort | \
FT_VALIDATE_morx | \
FT_VALIDATE_bsln | \
FT_VALIDATE_just | \
FT_VALIDATE_kern | \
FT_VALIDATE_opbd | \
FT_VALIDATE_trak | \
FT_VALIDATE_prop | \
FT_VALIDATE_lcar )
/**************************************************************************
*
* @function:
* FT_TrueTypeGX_Validate
*
* @description:
* Validate various TrueTypeGX 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_GXXXX for possible values.
*
* table_length ::
* The size of the `tables` array. Normally, @FT_VALIDATE_GX_LENGTH
* should be passed.
*
* @output:
* tables ::
* The array where all validated sfnt tables are stored. The array
* itself must be allocated by a client.
*
* @return:
* FreeType error code. 0~means success.
*
* @note:
* This function only works with TrueTypeGX fonts, returning an error
* otherwise.
*
* After use, the application should deallocate the buffers pointed to by
* each `tables` element, by calling @FT_TrueTypeGX_Free. A `NULL` value
* indicates that the table either doesn't exist in the font, the
* application hasn't asked for validation, or the validator doesn't have
* the ability to validate the sfnt table.
*/
FT_EXPORT( FT_Error )
FT_TrueTypeGX_Validate( FT_Face face,
FT_UInt validation_flags,
FT_Bytes tables[FT_VALIDATE_GX_LENGTH],
FT_UInt table_length );
/**************************************************************************
*
* @function:
* FT_TrueTypeGX_Free
*
* @description:
* Free the buffer allocated by TrueTypeGX validator.
*
* @input:
* face ::
* A handle to the input face.
*
* table ::
* The pointer to the buffer allocated by @FT_TrueTypeGX_Validate.
*
* @note:
* This function must be used to free the buffer allocated by
* @FT_TrueTypeGX_Validate only.
*/
FT_EXPORT( void )
FT_TrueTypeGX_Free( FT_Face face,
FT_Bytes table );
/**************************************************************************
*
* @enum:
* FT_VALIDATE_CKERNXXX
*
* @description:
* A list of bit-field constants used with @FT_ClassicKern_Validate to
* indicate the classic kern dialect or dialects. If the selected type
* doesn't fit, @FT_ClassicKern_Validate regards the table as invalid.
*
* @values:
* FT_VALIDATE_MS ::
* Handle the 'kern' table as a classic Microsoft kern table.
*
* FT_VALIDATE_APPLE ::
* Handle the 'kern' table as a classic Apple kern table.
*
* FT_VALIDATE_CKERN ::
* Handle the 'kern' as either classic Apple or Microsoft kern table.
*/
#define FT_VALIDATE_MS ( FT_VALIDATE_GX_START << 0 )
#define FT_VALIDATE_APPLE ( FT_VALIDATE_GX_START << 1 )
#define FT_VALIDATE_CKERN ( FT_VALIDATE_MS | FT_VALIDATE_APPLE )
/**************************************************************************
*
* @function:
* FT_ClassicKern_Validate
*
* @description:
* Validate classic (16-bit format) kern table to assure that the
* 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).
*
* The 'kern' table validator in @FT_TrueTypeGX_Validate deals with both
* the new 32-bit format and the classic 16-bit format, while
* FT_ClassicKern_Validate only supports the classic 16-bit format.
*
* @input:
* face ::
* A handle to the input face.
*
* validation_flags ::
* A bit field that specifies the dialect to be validated. See
* @FT_VALIDATE_CKERNXXX for possible values.
*
* @output:
* ckern_table ::
* A pointer to the kern table.
*
* @return:
* FreeType error code. 0~means success.
*
* @note:
* After use, the application should deallocate the buffers pointed to by
* `ckern_table`, by calling @FT_ClassicKern_Free. A `NULL` value
* indicates that the table doesn't exist in the font.
*/
FT_EXPORT( FT_Error )
FT_ClassicKern_Validate( FT_Face face,
FT_UInt validation_flags,
FT_Bytes *ckern_table );
/**************************************************************************
*
* @function:
* FT_ClassicKern_Free
*
* @description:
* Free the buffer allocated by classic Kern validator.
*
* @input:
* face ::
* A handle to the input face.
*
* table ::
* The pointer to the buffer that is allocated by
* @FT_ClassicKern_Validate.
*
* @note:
* This function must be used to free the buffer allocated by
* @FT_ClassicKern_Validate only.
*/
FT_EXPORT( void )
FT_ClassicKern_Free( FT_Face face,
FT_Bytes table );
/* */
FT_END_HEADER
#endif /* FTGXVAL_H_ */
/* END */