freetype1/lib/extend/ftxgdef.h

   1 /*******************************************************************
   2  *
   3  *  ftxgdef.h
   4  *
   5  *    TrueType Open GDEF table support
   6  *
   7  *  Copyright 1996-1999 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 #ifndef FTXOPEN_H
  19 #error "Don't include this file! Use ftxopen.h instead."
  20 #endif
  21
  22 #ifndef FTXGDEF_H
  23 #define FTXGDEF_H
  24
  25 #ifdef __cplusplus
  26 extern "C" {
  27 #endif
  28
  29 #define TTO_Err_Invalid_GDEF_SubTable_Format  0x1030
  30 #define TTO_Err_Invalid_GDEF_SubTable         0x1031
  31
  32
  33 /* GDEF glyph classes */
  34
  35 #define UNCLASSIFIED_GLYPH  0
  36 #define SIMPLE_GLYPH        1
  37 #define LIGATURE_GLYPH      2
  38 #define MARK_GLYPH          3
  39 #define COMPONENT_GLYPH     4
  40
  41 /* GDEF glyph properties, corresponding to class values 1-4.  Note that
  42    TTO_COMPONENT has no corresponding flag in the LookupFlag field.     */
  43
  44 #define TTO_BASE_GLYPH  0x0002
  45 #define TTO_LIGATURE    0x0004
  46 #define TTO_MARK        0x0008
  47 #define TTO_COMPONENT   0x0010
  48
  49
  50   /* Attachment related structures */
  51
  52   struct  TTO_AttachPoint_
  53   {
  54     TT_UShort   PointCount;             /* size of the PointIndex array */
  55     TT_UShort*  PointIndex;             /* array of contour points      */
  56   };
  57
  58   typedef struct TTO_AttachPoint_  TTO_AttachPoint;
  59
  60
  61   struct  TTO_AttachList_
  62   {
  63     TT_Bool           loaded;
  64
  65     TTO_Coverage      Coverage;         /* Coverage table              */
  66     TT_UShort         GlyphCount;       /* number of glyphs with
  67                                            attachments                 */
  68     TTO_AttachPoint*  AttachPoint;      /* array of AttachPoint tables */
  69   };
  70
  71   typedef struct TTO_AttachList_  TTO_AttachList;
  72
  73
  74   /* Ligature Caret related structures */
  75
  76   struct  TTO_CaretValueFormat1_
  77   {
  78     TT_Short  Coordinate;               /* x or y value (in design units) */
  79   };
  80
  81   typedef struct TTO_CaretValueFormat1_  TTO_CaretValueFormat1;
  82
  83
  84   struct  TTO_CaretValueFormat2_
  85   {
  86     TT_UShort  CaretValuePoint;         /* contour point index on glyph */
  87   };
  88
  89   typedef struct TTO_CaretValueFormat2_  TTO_CaretValueFormat2;
  90
  91
  92   struct  TTO_CaretValueFormat3_
  93   {
  94     TT_Short    Coordinate;             /* x or y value (in design units) */
  95     TTO_Device  Device;                 /* Device table for x or y value  */
  96   };
  97
  98   typedef struct TTO_CaretValueFormat3_  TTO_CaretValueFormat3;
  99
 100
 101   struct  TTO_CaretValueFormat4_
 102   {
 103     TT_UShort  IdCaretValue;            /* metric ID */
 104   };
 105
 106   typedef struct TTO_CaretValueFormat4_  TTO_CaretValueFormat4;
 107
 108
 109   struct  TTO_CaretValue_
 110   {
 111     TT_UShort  CaretValueFormat;        /* 1, 2, 3, or 4 */
 112
 113     union
 114     {
 115       TTO_CaretValueFormat1  cvf1;
 116       TTO_CaretValueFormat2  cvf2;
 117       TTO_CaretValueFormat3  cvf3;
 118       TTO_CaretValueFormat4  cvf4;
 119     } cvf;
 120   };
 121
 122   typedef struct TTO_CaretValue_  TTO_CaretValue;
 123
 124
 125   struct  TTO_LigGlyph_
 126   {
 127     TT_Bool          loaded;
 128
 129     TT_UShort        CaretCount;        /* number of caret values */
 130     TTO_CaretValue*  CaretValue;        /* array of caret values  */
 131   };
 132
 133   typedef struct TTO_LigGlyph_  TTO_LigGlyph;
 134
 135
 136   struct  TTO_LigCaretList_
 137   {
 138     TT_Bool        loaded;
 139
 140     TTO_Coverage   Coverage;            /* Coverage table            */
 141     TT_UShort      LigGlyphCount;       /* number of ligature glyphs */
 142     TTO_LigGlyph*  LigGlyph;            /* array of LigGlyph tables  */
 143   };
 144
 145   typedef struct TTO_LigCaretList_  TTO_LigCaretList;
 146
 147
 148   /* The `NewGlyphClasses' field is not defined in the TTO specification.
 149      We use it for fonts with a constructed `GlyphClassDef' structure
 150      (i.e., which don't have a GDEF table) to collect glyph classes
 151      assigned during the lookup process.  The number of arrays in this
 152      pointer array is GlyphClassDef->cd.cd2.ClassRangeCount+1; the nth
 153      array then contains the glyph class values of the glyphs not covered
 154      by the ClassRangeRecords structures with index n-1 and n.  We store
 155      glyph class values for four glyphs in a single array element.
 156
 157      `LastGlyph' is identical to the number of glyphs minus one in the
 158      font; we need it only if `NewGlyphClasses' is not NULL (to have an
 159      upper bound for the last array).
 160
 161      Note that we first store the file offset to the `MarkAttachClassDef'
 162      field (which has been introduced in OpenType 1.2) -- since the
 163      `Version' field value hasn't been increased to indicate that we have
 164      one more field for some obscure reason, we must parse the GSUB table
 165      to find out whether class values refer to this table.  Only then we
 166      can finally load the MarkAttachClassDef structure if necessary.      */
 167
 168   struct  TTO_GDEFHeader_
 169   {
 170     TT_Bool              loaded;
 171     TT_ULong             offset;
 172
 173     TT_Fixed             Version;
 174
 175     TTO_ClassDefinition  GlyphClassDef;
 176     TTO_AttachList       AttachList;
 177     TTO_LigCaretList     LigCaretList;
 178     TT_ULong             MarkAttachClassDef_offset;
 179     TTO_ClassDefinition  MarkAttachClassDef;        /* new in OT 1.2 */
 180
 181     TT_UShort            LastGlyph;
 182     TT_UShort**          NewGlyphClasses;
 183   };
 184
 185   typedef struct TTO_GDEFHeader_  TTO_GDEFHeader;
 186
 187
 188   /* finally, the GDEF API */
 189
 190   EXPORT_DEF
 191   TT_Error  TT_Init_GDEF_Extension( TT_Engine  engine );
 192
 193   EXPORT_DEF
 194   TT_Error  TT_Load_GDEF_Table( TT_Face          face,
 195                                 TTO_GDEFHeader*  gdef );
 196
 197   EXPORT_DEF
 198   TT_Error  TT_GDEF_Get_Glyph_Property( TTO_GDEFHeader*  gdef,
 199                                         TT_UShort        glyphID,
 200                                         TT_UShort*       property );
 201   EXPORT_DEF
 202   TT_Error  TT_GDEF_Build_ClassDefinition( TTO_GDEFHeader*  gdef,
 203                                            TT_UShort        num_glyphs,
 204                                            TT_UShort        glyph_count,
 205                                            TT_UShort*       glyph_array,
 206                                            TT_UShort*       class_array );
 207
 208
 209 #ifdef __cplusplus
 210 }
 211 #endif
 212
 213 #endif /* FTXGDEF_H */
 214
 215
 216 /* END */