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 */ 149