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_GPOS_H
27 #define HARFBUZZ_GPOS_H
28 
29 #include "harfbuzz-gdef.h"
30 #include "harfbuzz-buffer.h"
31 
32 HB_BEGIN_HEADER
33 
34 
35 /* Lookup types for glyph positioning */
36 
37 #define HB_GPOS_LOOKUP_SINGLE     1
38 #define HB_GPOS_LOOKUP_PAIR       2
39 #define HB_GPOS_LOOKUP_CURSIVE    3
40 #define HB_GPOS_LOOKUP_MARKBASE   4
41 #define HB_GPOS_LOOKUP_MARKLIG    5
42 #define HB_GPOS_LOOKUP_MARKMARK   6
43 #define HB_GPOS_LOOKUP_CONTEXT    7
44 #define HB_GPOS_LOOKUP_CHAIN      8
45 #define HB_GPOS_LOOKUP_EXTENSION  9
46 
47 #ifdef HB_SUPPORT_MULTIPLE_MASTER
48 /* A pointer to a function which accesses the PostScript interpreter.
49    Multiple Master fonts need this interface to convert a metric ID
50    (as stored in an OpenType font version 1.2 or higher) `metric_id'
51    into a metric value (returned in `metric_value').
52 
53    `data' points to the user-defined structure specified during a
54    call to HB_GPOS_Register_MM_Function().
55 
56    `metric_value' must be returned as a scaled value (but shouldn't
57    be rounded).                                                       */
58 
59 typedef HB_Error  (*HB_MMFunction)(HB_Font       font,
60 				    HB_UShort    metric_id,
61 				    HB_Fixed*      metric_value,
62 				    void*        data );
63 #endif
64 
65 
66 struct  HB_GPOSHeader_
67 {
68   HB_16Dot16           Version;
69 
70   HB_ScriptList     ScriptList;
71   HB_FeatureList    FeatureList;
72   HB_LookupList     LookupList;
73 
74   HB_GDEFHeader*    gdef;
75 
76 #ifdef HB_SUPPORT_MULTIPLE_MASTER
77   /* this is OpenType 1.2 -- Multiple Master fonts need this
78      callback function to get various metric values from the
79      PostScript interpreter.                                 */
80 
81   HB_MMFunction     mmfunc;
82   void*              data;
83 #endif
84 };
85 
86 typedef struct HB_GPOSHeader_  HB_GPOSHeader;
87 typedef HB_GPOSHeader* HB_GPOS;
88 
89 
90 HB_Error  HB_Load_GPOS_Table( HB_Stream stream,
91                               HB_GPOSHeader** gpos,
92 			      HB_GDEFHeader*  gdef,
93                               HB_Stream       gdefStream );
94 
95 
96 HB_Error  HB_Done_GPOS_Table( HB_GPOSHeader* gpos );
97 
98 
99 HB_Error  HB_GPOS_Select_Script( HB_GPOSHeader*  gpos,
100 				 HB_UInt         script_tag,
101 				 HB_UShort*       script_index );
102 
103 HB_Error  HB_GPOS_Select_Language( HB_GPOSHeader*  gpos,
104 				   HB_UInt         language_tag,
105 				   HB_UShort        script_index,
106 				   HB_UShort*       language_index,
107 				   HB_UShort*       req_feature_index );
108 
109 HB_Error  HB_GPOS_Select_Feature( HB_GPOSHeader*  gpos,
110 				  HB_UInt         feature_tag,
111 				  HB_UShort        script_index,
112 				  HB_UShort        language_index,
113 				  HB_UShort*       feature_index );
114 
115 
116 HB_Error  HB_GPOS_Query_Scripts( HB_GPOSHeader*  gpos,
117 				 HB_UInt**       script_tag_list );
118 
119 HB_Error  HB_GPOS_Query_Languages( HB_GPOSHeader*  gpos,
120 				   HB_UShort        script_index,
121 				   HB_UInt**       language_tag_list );
122 
123 HB_Error  HB_GPOS_Query_Features( HB_GPOSHeader*  gpos,
124 				  HB_UShort        script_index,
125 				  HB_UShort        language_index,
126 				  HB_UInt**       feature_tag_list );
127 
128 
129 HB_Error  HB_GPOS_Add_Feature( HB_GPOSHeader*  gpos,
130 			       HB_UShort        feature_index,
131 			       HB_UInt          property );
132 
133 HB_Error  HB_GPOS_Clear_Features( HB_GPOSHeader*  gpos );
134 
135 
136 #ifdef HB_SUPPORT_MULTIPLE_MASTER
137 HB_Error  HB_GPOS_Register_MM_Function( HB_GPOSHeader*  gpos,
138 					HB_MMFunction   mmfunc,
139 					void*            data );
140 #endif
141 
142 /* If `dvi' is TRUE, glyph contour points for anchor points and device
143    tables are ignored -- you will get device independent values.         */
144 
145 
146 HB_Error  HB_GPOS_Apply_String( HB_Font           font,
147 				HB_GPOSHeader*   gpos,
148 				HB_UShort         load_flags,
149 				HB_Buffer        buffer,
150 				HB_Bool           dvi,
151 				HB_Bool           r2l );
152 
153 HB_END_HEADER
154 
155 #endif /* HARFBUZZ_GPOS_H */
156