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