src/hb-old/harfbuzz-gsub.h

   1 /*
   2  * Copyright (C) 1998-2004  David Turner and Werner Lemberg
   3  * Copyright (C) 2006  Behdad Esfahbod
   4  *
   5  * This is part of HarfBuzz, an OpenType Layout engine library.
   6  *
   7  * Permission is hereby granted, without written agreement and without
   8  * license or royalty fees, to use, copy, modify, and distribute this
   9  * software and its documentation for any purpose, provided that the
  10  * above copyright notice and the following two paragraphs appear in
  11  * all copies of this software.
  12  *
  13  * IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE TO ANY PARTY FOR
  14  * DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES
  15  * ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN
  16  * IF THE COPYRIGHT HOLDER HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH
  17  * DAMAGE.
  18  *
  19  * THE COPYRIGHT HOLDER SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING,
  20  * BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
  21  * FITNESS FOR A PARTICULAR PURPOSE.  THE SOFTWARE PROVIDED HEREUNDER IS
  22  * ON AN "AS IS" BASIS, AND THE COPYRIGHT HOLDER HAS NO OBLIGATION TO
  23  * PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
  24  */
  25
  26 #ifndef HARFBUZZ_GSUB_H
  27 #define HARFBUZZ_GSUB_H
  28
  29 #include "harfbuzz-gdef.h"
  30 #include "harfbuzz-buffer.h"
  31
  32 HB_BEGIN_HEADER
  33
  34
  35 #ifdef HB_USE_PACKED_STRUCTS
  36 #pragma pack(push, 1)
  37 #endif
  38
  39 /* Lookup types for glyph substitution */
  40
  41 #define HB_GSUB_LOOKUP_SINGLE        1
  42 #define HB_GSUB_LOOKUP_MULTIPLE      2
  43 #define HB_GSUB_LOOKUP_ALTERNATE     3
  44 #define HB_GSUB_LOOKUP_LIGATURE      4
  45 #define HB_GSUB_LOOKUP_CONTEXT       5
  46 #define HB_GSUB_LOOKUP_CHAIN         6
  47 #define HB_GSUB_LOOKUP_EXTENSION     7
  48 #define HB_GSUB_LOOKUP_REVERSE_CHAIN 8
  49
  50
  51 /* A pointer to a function which selects the alternate glyph.  `pos' is
  52    the position of the glyph with index `glyphID', `num_alternates'
  53    gives the number of alternates in the `alternates' array.  `data'
  54    points to the user-defined structure specified during a call to
  55    HB_GSUB_Register_Alternate_Function().  The function must return an
  56    index into the `alternates' array.                                   */
  57
  58 typedef HB_UShort  (*HB_AltFunction)(HB_UInt    pos,
  59                                       HB_UShort   glyphID,
  60                                       HB_UShort   num_alternates,
  61                                       HB_UShort*  alternates,
  62                                       void*       data );
  63
  64
  65 struct  HB_GSUBHeader_
  66 {
  67   HB_GDEFHeader*  gdef;
  68
  69   /* the next two fields are used for an alternate substitution callback
  70      function to select the proper alternate glyph.                      */
  71
  72   void*            data;
  73   HB_AltFunction  altfunc;
  74
  75   HB_UInt         offset;
  76
  77   HB_16Dot16         Version;
  78
  79   HB_ScriptList   ScriptList;
  80   HB_FeatureList  FeatureList;
  81   HB_LookupList   LookupList;
  82 };
  83
  84 typedef struct HB_GSUBHeader_   HB_GSUBHeader;
  85 typedef HB_GSUBHeader*  HB_GSUB;
  86
  87
  88 HB_Error  HB_Load_GSUB_Table( HB_Stream       stream,
  89                               HB_GSUBHeader** gsub,
  90                               HB_GDEFHeader*  gdef,
  91                               HB_Stream       gdefStream );
  92
  93
  94 HB_Error  HB_Done_GSUB_Table( HB_GSUBHeader*  gsub );
  95
  96
  97 HB_Error  HB_GSUB_Select_Script( HB_GSUBHeader*  gsub,
  98                                  HB_UInt         script_tag,
  99                                  HB_UShort*       script_index );
 100
 101 HB_Error  HB_GSUB_Select_Language( HB_GSUBHeader*  gsub,
 102                                    HB_UInt         language_tag,
 103                                    HB_UShort        script_index,
 104                                    HB_UShort*       language_index,
 105                                    HB_UShort*       req_feature_index );
 106
 107 HB_Error  HB_GSUB_Select_Feature( HB_GSUBHeader*  gsub,
 108                                   HB_UInt         feature_tag,
 109                                   HB_UShort        script_index,
 110                                   HB_UShort        language_index,
 111                                   HB_UShort*       feature_index );
 112
 113
 114 HB_Error  HB_GSUB_Query_Scripts( HB_GSUBHeader*  gsub,
 115                                  HB_UInt**       script_tag_list );
 116
 117 HB_Error  HB_GSUB_Query_Languages( HB_GSUBHeader*  gsub,
 118                                    HB_UShort        script_index,
 119                                    HB_UInt**       language_tag_list );
 120
 121 HB_Error  HB_GSUB_Query_Features( HB_GSUBHeader*  gsub,
 122                                   HB_UShort        script_index,
 123                                   HB_UShort        language_index,
 124                                   HB_UInt**       feature_tag_list );
 125
 126
 127 HB_Error  HB_GSUB_Add_Feature( HB_GSUBHeader*  gsub,
 128                                HB_UShort        feature_index,
 129                                HB_UInt          property );
 130
 131 HB_Error  HB_GSUB_Clear_Features( HB_GSUBHeader*  gsub );
 132
 133
 134 HB_Error  HB_GSUB_Register_Alternate_Function( HB_GSUBHeader*  gsub,
 135                                                HB_AltFunction  altfunc,
 136                                                void*            data );
 137
 138
 139 HB_Error  HB_GSUB_Apply_String( HB_GSUBHeader*   gsub,
 140                                 HB_Buffer        buffer );
 141
 142 #ifdef HB_USE_PACKED_STRUCTS
 143 #pragma pack(pop)
 144 #endif
 145
 146 HB_END_HEADER
 147
 148 #endif /* HARFBUZZ_GSUB_H */