include/ftotval.h

   1 /***************************************************************************/
   2 /*                                                                         */
   3 /*  ftotval.h                                                              */
   4 /*                                                                         */
   5 /*    FreeType API for validating OpenType tables (specification).         */
   6 /*                                                                         */
   7 /*  Copyright 2004-2007, 2013, 2014 by                                     */
   8 /*  David Turner, Robert Wilhelm, and Werner Lemberg.                      */
   9 /*                                                                         */
  10 /*  This file is part of the FreeType project, and may only be used,       */
  11 /*  modified, and distributed under the terms of the FreeType project      */
  12 /*  license, LICENSE.TXT.  By continuing to use, modify, or distribute     */
  13 /*  this file you indicate that you have read the license and              */
  14 /*  understand and accept it fully.                                        */
  15 /*                                                                         */
  16 /***************************************************************************/
  17
  18
  19 /***************************************************************************/
  20 /*                                                                         */
  21 /*                                                                         */
  22 /* Warning: This module might be moved to a different library in the       */
  23 /*          future to avoid a tight dependency between FreeType and the    */
  24 /*          OpenType specification.                                        */
  25 /*                                                                         */
  26 /*                                                                         */
  27 /***************************************************************************/
  28
  29
  30 #ifndef __FTOTVAL_H__
  31 #define __FTOTVAL_H__
  32
  33 #include <ft2build.h>
  34 #include FT_FREETYPE_H
  35
  36 #ifdef FREETYPE_H
  37 #error "freetype.h of FreeType 1 has been loaded!"
  38 #error "Please fix the directory search order for header files"
  39 #error "so that freetype.h of FreeType 2 is found first."
  40 #endif
  41
  42
  43 FT_BEGIN_HEADER
  44
  45
  46   /*************************************************************************/
  47   /*                                                                       */
  48   /* <Section>                                                             */
  49   /*    ot_validation                                                      */
  50   /*                                                                       */
  51   /* <Title>                                                               */
  52   /*    OpenType Validation                                                */
  53   /*                                                                       */
  54   /* <Abstract>                                                            */
  55   /*    An API to validate OpenType tables.                                */
  56   /*                                                                       */
  57   /* <Description>                                                         */
  58   /*    This section contains the declaration of functions to validate     */
  59   /*    some OpenType tables (BASE, GDEF, GPOS, GSUB, JSTF, MATH).         */
  60   /*                                                                       */
  61   /* <Order>                                                               */
  62   /*    FT_OpenType_Validate                                               */
  63   /*    FT_OpenType_Free                                                   */
  64   /*                                                                       */
  65   /*    FT_VALIDATE_OTXXX                                                  */
  66   /*                                                                       */
  67   /*************************************************************************/
  68
  69
  70  /**********************************************************************
  71   *
  72   * @enum:
  73   *    FT_VALIDATE_OTXXX
  74   *
  75   * @description:
  76   *    A list of bit-field constants used with @FT_OpenType_Validate to
  77   *    indicate which OpenType tables should be validated.
  78   *
  79   * @values:
  80   *    FT_VALIDATE_BASE ::
  81   *      Validate BASE table.
  82   *
  83   *    FT_VALIDATE_GDEF ::
  84   *      Validate GDEF table.
  85   *
  86   *    FT_VALIDATE_GPOS ::
  87   *      Validate GPOS table.
  88   *
  89   *    FT_VALIDATE_GSUB ::
  90   *      Validate GSUB table.
  91   *
  92   *    FT_VALIDATE_JSTF ::
  93   *      Validate JSTF table.
  94   *
  95   *    FT_VALIDATE_MATH ::
  96   *      Validate MATH table.
  97   *
  98   *    FT_VALIDATE_OT ::
  99   *      Validate all OpenType tables (BASE, GDEF, GPOS, GSUB, JSTF, MATH).
 100   *
 101   */
 102 #define FT_VALIDATE_BASE  0x0100
 103 #define FT_VALIDATE_GDEF  0x0200
 104 #define FT_VALIDATE_GPOS  0x0400
 105 #define FT_VALIDATE_GSUB  0x0800
 106 #define FT_VALIDATE_JSTF  0x1000
 107 #define FT_VALIDATE_MATH  0x2000
 108
 109 #define FT_VALIDATE_OT  FT_VALIDATE_BASE | \
 110                         FT_VALIDATE_GDEF | \
 111                         FT_VALIDATE_GPOS | \
 112                         FT_VALIDATE_GSUB | \
 113                         FT_VALIDATE_JSTF | \
 114                         FT_VALIDATE_MATH
 115
 116  /**********************************************************************
 117   *
 118   * @function:
 119   *    FT_OpenType_Validate
 120   *
 121   * @description:
 122   *    Validate various OpenType tables to assure that all offsets and
 123   *    indices are valid.  The idea is that a higher-level library that
 124   *    actually does the text layout can access those tables without
 125   *    error checking (which can be quite time consuming).
 126   *
 127   * @input:
 128   *    face ::
 129   *       A handle to the input face.
 130   *
 131   *    validation_flags ::
 132   *       A bit field that specifies the tables to be validated.  See
 133   *       @FT_VALIDATE_OTXXX for possible values.
 134   *
 135   * @output:
 136   *    BASE_table ::
 137   *       A pointer to the BASE table.
 138   *
 139   *    GDEF_table ::
 140   *       A pointer to the GDEF table.
 141   *
 142   *    GPOS_table ::
 143   *       A pointer to the GPOS table.
 144   *
 145   *    GSUB_table ::
 146   *       A pointer to the GSUB table.
 147   *
 148   *    JSTF_table ::
 149   *       A pointer to the JSTF table.
 150   *
 151   * @return:
 152   *   FreeType error code.  0~means success.
 153   *
 154   * @note:
 155   *   This function only works with OpenType fonts, returning an error
 156   *   otherwise.
 157   *
 158   *   After use, the application should deallocate the five tables with
 159   *   @FT_OpenType_Free.  A NULL value indicates that the table either
 160   *   doesn't exist in the font, or the application hasn't asked for
 161   *   validation.
 162   */
 163   FT_EXPORT( FT_Error )
 164   FT_OpenType_Validate( FT_Face    face,
 165                         FT_UInt    validation_flags,
 166                         FT_Bytes  *BASE_table,
 167                         FT_Bytes  *GDEF_table,
 168                         FT_Bytes  *GPOS_table,
 169                         FT_Bytes  *GSUB_table,
 170                         FT_Bytes  *JSTF_table );
 171
 172  /**********************************************************************
 173   *
 174   * @function:
 175   *    FT_OpenType_Free
 176   *
 177   * @description:
 178   *    Free the buffer allocated by OpenType validator.
 179   *
 180   * @input:
 181   *    face ::
 182   *       A handle to the input face.
 183   *
 184   *    table ::
 185   *       The pointer to the buffer that is allocated by
 186   *       @FT_OpenType_Validate.
 187   *
 188   * @note:
 189   *   This function must be used to free the buffer allocated by
 190   *   @FT_OpenType_Validate only.
 191   */
 192   FT_EXPORT( void )
 193   FT_OpenType_Free( FT_Face   face,
 194                     FT_Bytes  table );
 195
 196   /* */
 197
 198
 199 FT_END_HEADER
 200
 201 #endif /* __FTOTVAL_H__ */
 202
 203
 204 /* END */