2 * Copyright (C) 1998-2004 David Turner and Werner Lemberg
3 * Copyright (C) 2006 Behdad Esfahbod
5 * This is part of HarfBuzz, an OpenType Layout engine library.
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.
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
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.
26 #ifndef HARFBUZZ_GSUB_H
27 #define HARFBUZZ_GSUB_H
29 #include "harfbuzz-gdef.h"
30 #include "harfbuzz-buffer.h"
35 #ifdef HB_USE_PACKED_STRUCTS
39 /* Lookup types for glyph substitution */
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
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. */
58 typedef HB_UShort (*HB_AltFunction)(HB_UInt pos,
60 HB_UShort num_alternates,
61 HB_UShort* alternates,
69 /* the next two fields are used for an alternate substitution callback
70 function to select the proper alternate glyph. */
73 HB_AltFunction altfunc;
79 HB_ScriptList ScriptList;
80 HB_FeatureList FeatureList;
81 HB_LookupList LookupList;
84 typedef struct HB_GSUBHeader_ HB_GSUBHeader;
85 typedef HB_GSUBHeader* HB_GSUB;
88 HB_Error HB_Load_GSUB_Table( HB_Stream stream,
91 HB_Stream gdefStream );
94 HB_Error HB_Done_GSUB_Table( HB_GSUBHeader* gsub );
97 HB_Error HB_GSUB_Select_Script( HB_GSUBHeader* gsub,
99 HB_UShort* script_index );
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 );
107 HB_Error HB_GSUB_Select_Feature( HB_GSUBHeader* gsub,
109 HB_UShort script_index,
110 HB_UShort language_index,
111 HB_UShort* feature_index );
114 HB_Error HB_GSUB_Query_Scripts( HB_GSUBHeader* gsub,
115 HB_UInt** script_tag_list );
117 HB_Error HB_GSUB_Query_Languages( HB_GSUBHeader* gsub,
118 HB_UShort script_index,
119 HB_UInt** language_tag_list );
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 );
127 HB_Error HB_GSUB_Add_Feature( HB_GSUBHeader* gsub,
128 HB_UShort feature_index,
131 HB_Error HB_GSUB_Clear_Features( HB_GSUBHeader* gsub );
134 HB_Error HB_GSUB_Register_Alternate_Function( HB_GSUBHeader* gsub,
135 HB_AltFunction altfunc,
139 HB_Error HB_GSUB_Apply_String( HB_GSUBHeader* gsub,
142 #ifdef HB_USE_PACKED_STRUCTS
148 #endif /* HARFBUZZ_GSUB_H */