kc3-lang/freetype/src/otlayout/oltypes.h

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• Hash : 18789bfe
  Author :
  Date : 2000-02-15T12:53:31
  

  Added prototype OpenType Layout support sources. This is not a port of the OTL extension of FT 1.x, as it uses a very different design. These sources are placed here for comments and peer-review

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• src/otlayout/oltypes.h

• #ifndef OLTYPES_H
  #define OLTYPES_H
  
  #include <ftobjs.h>
  #include <tttypes.h>
  
   /*************************************************************
    *
    * <Struct> OTL_Table
    *
    * <Description>
    *    The base table of most OpenType Layout sub-tables.
    *    Provides a simple way to scan a table for script,
    *    languages, features and lookups..
    *
    * <Fields>
    *    num_scripts  :: number of scripts in table's script list
    *    script_tags  :: array of tags for each table script
    *
    *    max_languages :: max number of languages for any script in
    *                     the table.
    *    num_languages :: number of languages available for current script
    *    language_tags :: tags of all languages available for current script.
    *
    *    max_features  :: total number of features in table
    *    feature_tags  :: tags of all features for current script/language
    *    
    *    max_lookups   :: total number of lookups in table
    *    lookups       :: selection flags for all lookups for current
    *                     feature list.
    *
    ****************************************************************/
  
    typedef enum OTL_Type_
    {
      otl_type_none = 0,
      otl_type_base,
      otl_type_gdef,
      otl_type_gpos,
      otl_type_gsub,
      otl_type_jstf
    
    } OTL_Type;
    
    
    typedef struct OTL_Table_
    {
      FT_Memory memory;
  
      TT_Int    num_scripts;
      TT_Tag*   script_tags;
      
      TT_Int    max_languages;
      TT_Int    num_languages;
      TT_Tag*   language_tags;
  
      TT_Int    max_features;
      TT_Tag*   feature_tags;
      TT_Bool*  features;
  
      TT_Int    max_lookups;
      TT_Bool*  lookups;
      
      TT_Byte*  scripts_table;
      TT_Long   scripts_len;
      
      TT_Byte*  features_table;
      TT_Long*  features_len;
      
      TT_Byte*  lookups_table;
      TT_Byte*  lookups_len;
  
      TT_Byte*  cur_script;   /* current script   */
      TT_Byte*  cur_language; /* current language */
      
      TT_Byte*  cur_base_values;
      TT_Byte*  cur_min_max;
  
      OTL_Type  otl_type;
  
    } OTL_Table;
  
  
    LOCAL_DEF
    TT_Error  OTL_Table_Init( OTL_Table*  table,
                              FT_Memory   memory );
  
    LOCAL_DEF
    TT_Error  OTL_Table_Set_Scripts( OTL_Table*  table,
                                     TT_Byte*    bytes,
                                     TT_Long     len,
                                     OTL_Type    otl_type );
  
    LOCAL_DEF
    TT_Error  OTL_Table_Set_Features( OTL_Table*  table,
                                      TT_Byte*    bytes,
                                      TT_Long     len );
  
    LOCAL_DEF
    TT_Error  OTL_Table_Set_Lookups( OTL_Table*  table,
                                     TT_Byte*    bytes,
                                     TT_Long     len );
  
    LOCAL_DEF
    void      OTL_Table_Done( OTL_Table*  table );
  
  
  
  /*****************************************************
   *
   *  Typical uses:
   *
   *  - after OTL_Table_Set_Scripts have been called :
   *
   *      table->script_tags contains the list of tags of all
   *      scripts defined for this table.
   *
   *      table->num_scripts is the number of scripts
   *
   */
   
  /********************************************************
   *
   *  - after calling OTL_Table_Set_Features:
   *
   *      table->max_features is the number of all features
   *      in the table
   *
   *      table->feature_tags is the list of tags of all
   *      features in the table
   *
   *      table->features[] is an array of boolean used to
   *      indicate which feature is active for a given script/language
   *      it is empty (zero-filled) by default.
   *
   */
   
  /*******************************************************************
   *
   *  - after calling OTL_Get_Languages_List(script_tag):
   *
   *      table->num_languages is the number of language systems
   *      available for the script, including the default
   *      langsys if there is one
   *
   *      table->language_tags contains the list of tags of all
   *      languages for the script. Note that the default langsys
   *      has tag "0" and is always placed first in "language_tags".
   *
   *
   *
   */
    LOCAL_DEF
    void  OTL_Get_Languages_List( OTL_Table*  table,
                                  TT_ULong    script_tag );
  
  
  /*******************************************************************
   *
   *  - after calling OTL_Get_Features_List(language_tag):
   *
   *      table->features[] is an array of booleans used to indicate
   *      which features are active for the current script/language
   *
   *      note that this function must be called after OTL_Get_Languages
   *      which remembers the last "script_tag" used..
   *
   *      A client application can change the table->features[] array
   *      to add or remove features from the list.
   *
   *
   *
   */
    LOCAL_DEF
    void OTL_Get_Features_List( OTL_Table*  table,
                                TT_ULong    language_tag );
  
    LOCAL_DEF
    void OTL_Get_Baseline_Values( OTL_Table*  table,
                                  TT_ULong    language_tag );
  
    LOCAL_DEF
    void OTL_Get_Justification( OTL_Table*  table,
                                TT_ULong    language_tag );
   
  /*******************************************************************
   *
   *  - after calling OTL_Get_Lookups_List():
   *
   *      The function uses the table->features[] array of boolean
   *      to determine which lookups must be processed.
   *
   *      It fills the table->lookups[] array accordingly. It is also
   *      an array of booleans (one for each lookup).
   *
   *
   */
  
    LOCAL_DEF
    void  OTL_Get_Lookups_List( OTL_Table*  table );
  
  
  /***************************************************************
   *
   *  So the whole thing looks like:
   *
   *
   *  1.  A client specifies a given script and requests available
   *      language through OTL_Get_Languages_List()
   *
   *  2.  It selects the language tag it needs, then calls
   *      OTL_Get_Features_List()
   *
   *  3.  It updates the list of active features if it needs to
   *
   *  4.  It calls OTL_Get_Lookups_List()
   *      It now has a list of active lookups in "table->lookups[]"
   *
   *  5.  The lookups are processed according to the table's type..
   *
   */
  
  
  
    LOCAL_DEF
    TT_Long  OTL_Get_Coverage_Index( TT_Byte*  coverage,
                                     TT_UInt   glyph_id );
  
  
  #define OTL_Byte(p)   (p++, p[-1])
  
  #define OTL_UShort(p) (p+=2, ((TT_UShort)p[-2] << 8) | p[-1])
  
  #define OTL_ULong(p)  (p+=4, ((TT_ULong)p[-4] << 24) |        \
                               ((TT_ULong)p[-3] << 16) |        \
                               ((TT_ULong)p[-2] << 8 ) | p[-1] )
  
  #endif /* OLTYPES_H */
  

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