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      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