freetype2/include/freetype/ftgxval.h

/***************************************************************************/
/*                                                                         */
/*  ftgxval.h                                                              */
/*                                                                         */
/*    FreeType API for validating TrueTypeGX/AAT tables (specification).   */
/*                                                                         */
/*  Copyright 2004, 2005, 2006 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 <ft2build.h>
#include FT_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).                                                 */
  /*                                                                       */
  /*************************************************************************/


  /*************************************************************************/
  /*                                                                       */
  /*                                                                       */
  /* 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 which
  *    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 which 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 which
  *    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 which 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 */