www.pudn.com > freetype.rar > sfnt.h

/***************************************************************************/ 
/*                                                                         */ 
/*  sfnt.h                                                                 */ 
/*                                                                         */ 
/*    High-level `sfnt' driver interface (specification).                  */ 
/*                                                                         */ 
/*  Copyright 1996-2001, 2002 by                                           */ 
/*  David Turner, Robert Wilhelm, and Werner Lemberg.                      */ 
/*                                                                         */ 
/*  This file is part of the FreeType project, and may only be used,       */ 
/*  modified, and distributed under the terms of the FreeType project      */ 
/*  license, LICENSE.TXT.  By continuing to use, modify, or distribute     */ 
/*  this file you indicate that you have read the license and              */ 
/*  understand and accept it fully.                                        */ 
/*                                                                         */ 
/***************************************************************************/ 
 
 
#ifndef __SFNT_H__ 
#define __SFNT_H__ 
 
 
#include "ft2build.h" 
#include "freetype/internal/ftdriver.h" 
#include "freetype/internal/tttypes.h" 
 
 
FT_BEGIN_HEADER 
 
 
  /*************************************************************************/ 
  /*                                                                       */ 
  /*                                                             */ 
  /*    TT_Init_Face_Func                                                  */ 
  /*                                                                       */ 
  /*                                                          */ 
  /*    First part of the SFNT face object initialization.  This will find */ 
  /*    the face in a SFNT file or collection, and load its format tag in  */ 
  /*    face->format_tag.                                                  */ 
  /*                                                                       */ 
  /*                                                                */ 
  /*    stream     :: The input stream.                                    */ 
  /*                                                                       */ 
  /*    face       :: A handle to the target face object.                  */ 
  /*                                                                       */ 
  /*    face_index :: The index of the TrueType font, if we are opening a  */ 
  /*                  collection.                                          */ 
  /*                                                                       */ 
  /*    num_params :: The number of additional parameters.                 */ 
  /*                                                                       */ 
  /*    params     :: Optional additional parameters.                      */ 
  /*                                                                       */ 
  /*                                                               */ 
  /*    FreeType error code.  0 means success.                             */ 
  /*                                                                       */ 
  /*                                                                 */ 
  /*    The stream cursor must be at the font file's origin.               */ 
  /*                                                                       */ 
  /*    This function recognizes fonts embedded in a `TrueType             */ 
  /*    collection'.                                                       */ 
  /*                                                                       */ 
  /*    Once the format tag has been validated by the font driver, it      */ 
  /*    should then call the TT_Load_Face_Func() callback to read the rest */ 
  /*    of the SFNT tables in the object.                                  */ 
  /*                                                                       */ 
  typedef FT_Error 
  (*TT_Init_Face_Func)( FT_Stream      stream, 
                        TT_Face        face, 
                        FT_Int         face_index, 
                        FT_Int         num_params, 
                        FT_Parameter*  params ); 
 
 
  /*************************************************************************/ 
  /*                                                                       */ 
  /*                                                             */ 
  /*    TT_Load_Face_Func                                                  */ 
  /*                                                                       */ 
  /*                                                          */ 
  /*    Second part of the SFNT face object initialization.  This will     */ 
  /*    load the common SFNT tables (head, OS/2, maxp, metrics, etc.) in   */ 
  /*    the face object.                                                   */ 
  /*                                                                       */ 
  /*                                                                */ 
  /*    stream     :: The input stream.                                    */ 
  /*                                                                       */ 
  /*    face       :: A handle to the target face object.                  */ 
  /*                                                                       */ 
  /*    face_index :: The index of the TrueType font, if we are opening a  */ 
  /*                  collection.                                          */ 
  /*                                                                       */ 
  /*    num_params :: The number of additional parameters.                 */ 
  /*                                                                       */ 
  /*    params     :: Optional additional parameters.                      */ 
  /*                                                                       */ 
  /*                                                               */ 
  /*    FreeType error code.  0 means success.                             */ 
  /*                                                                       */ 
  /*                                                                 */ 
  /*    This function must be called after TT_Init_Face_Func().            */ 
  /*                                                                       */ 
  typedef FT_Error 
  (*TT_Load_Face_Func)( FT_Stream      stream, 
                        TT_Face        face, 
                        FT_Int         face_index, 
                        FT_Int         num_params, 
                        FT_Parameter*  params ); 
 
 
  /*************************************************************************/ 
  /*                                                                       */ 
  /*                                                             */ 
  /*    TT_Done_Face_Func                                                  */ 
  /*                                                                       */ 
  /*                                                          */ 
  /*    A callback used to delete the common SFNT data from a face.        */ 
  /*                                                                       */ 
  /*                                                                */ 
  /*    face :: A handle to the target face object.                        */ 
  /*                                                                       */ 
  /*                                                                 */ 
  /*    This function does NOT destroy the face object.                    */ 
  /*                                                                       */ 
  typedef void 
  (*TT_Done_Face_Func)( TT_Face  face ); 
 
 
  typedef FT_Module_Interface 
  (*SFNT_Get_Interface_Func)( FT_Module    module, 
                              const char*  func_interface ); 
 
 
  /*************************************************************************/ 
  /*                                                                       */ 
  /*                                                             */ 
  /*    TT_Load_SFNT_HeaderRec_Func                                        */ 
  /*                                                                       */ 
  /*                                                          */ 
  /*    Loads the header of a SFNT font file.  Supports collections.       */ 
  /*                                                                       */ 
  /*                                                                */ 
  /*    face       :: A handle to the target face object.                  */ 
  /*                                                                       */ 
  /*    stream     :: The input stream.                                    */ 
  /*                                                                       */ 
  /*    face_index :: The index of the TrueType font, if we are opening a  */ 
  /*                  collection.                                          */ 
  /*                                                                       */ 
  /* 
                                                              */ 
  /*    sfnt       :: The SFNT header.                                     */ 
  /*                                                                       */ 
  /*                                                               */ 
  /*    FreeType error code.  0 means success.                             */ 
  /*                                                                       */ 
  /*                                                                 */ 
  /*    The stream cursor must be at the font file's origin.               */ 
  /*                                                                       */ 
  /*    This function recognizes fonts embedded in a `TrueType             */ 
  /*    collection'.                                                       */ 
  /*                                                                       */ 
  /*    This function checks that the header is valid by looking at the    */ 
  /*    values of `search_range', `entry_selector', and `range_shift'.     */ 
  /*                                                                       */ 
  typedef FT_Error 
  (*TT_Load_SFNT_HeaderRec_Func)( TT_Face      face, 
                                  FT_Stream    stream, 
                                  FT_Long      face_index, 
                                  SFNT_Header  sfnt ); 
 
 
  /*************************************************************************/ 
  /*                                                                       */ 
  /*                                                             */ 
  /*    TT_Load_Directory_Func                                             */ 
  /*                                                                       */ 
  /*                                                          */ 
  /*    Loads the table directory into a face object.                      */ 
  /*                                                                       */ 
  /*                                                                */ 
  /*    face      :: A handle to the target face object.                   */ 
  /*                                                                       */ 
  /*    stream    :: The input stream.                                     */ 
  /*                                                                       */ 
  /*    sfnt      :: The SFNT header.                                      */ 
  /*                                                                       */ 
  /*                                                               */ 
  /*    FreeType error code.  0 means success.                             */ 
  /*                                                                       */ 
  /*                                                                 */ 
  /*    The stream cursor must be on the first byte after the 4-byte font  */ 
  /*    format tag.  This is the case just after a call to                 */ 
  /*    TT_Load_Format_Tag().                                              */ 
  /*                                                                       */ 
  typedef FT_Error 
  (*TT_Load_Directory_Func)( TT_Face      face, 
                             FT_Stream    stream, 
                             SFNT_Header  sfnt ); 
 
 
  /*************************************************************************/ 
  /*                                                                       */ 
  /*                                                             */ 
  /*    TT_Load_Any_Func                                                   */ 
  /*                                                                       */ 
  /*                                                          */ 
  /*    Loads any font table into client memory.                           */ 
  /*                                                                       */ 
  /*                                                                */ 
  /*    face   :: The face object to look for.                             */ 
  /*                                                                       */ 
  /*    tag    :: The tag of table to load.  Use the value 0 if you want   */ 
  /*              to access the whole font file, else set this parameter   */ 
  /*              to a valid TrueType table tag that you can forge with    */ 
  /*              the MAKE_TT_TAG macro.                                   */ 
  /*                                                                       */ 
  /*    offset :: The starting offset in the table (or the file if         */ 
  /*              tag == 0).                                               */ 
  /*                                                                       */ 
  /*    length :: The address of the decision variable:                    */ 
  /*                                                                       */ 
  /*                If length == NULL:                                     */ 
  /*                  Loads the whole table.  Returns an error if          */ 
  /*                  `offset' == 0!                                       */ 
  /*                                                                       */ 
  /*                If *length == 0:                                       */ 
  /*                  Exits immediately; returning the length of the given */ 
  /*                  table or of the font file, depending on the value of */ 
  /*                  `tag'.                                               */ 
  /*                                                                       */ 
  /*                If *length != 0:                                       */ 
  /*                  Loads the next `length' bytes of table or font,      */ 
  /*                  starting at offset `offset' (in table or font too).  */ 
  /*                                                                       */ 
  /* 
                                                              */ 
  /*    buffer :: The address of target buffer.                            */ 
  /*                                                                       */ 
  /*                                                               */ 
  /*    TrueType error code.  0 means success.                             */ 
  /*                                                                       */ 
  typedef FT_Error 
  (*TT_Load_Any_Func)( TT_Face    face, 
                       FT_ULong   tag, 
                       FT_Long    offset, 
                       FT_Byte   *buffer, 
                       FT_ULong*  length ); 
 
 
  /*************************************************************************/ 
  /*                                                                       */ 
  /*                                                             */ 
  /*    TT_Load_SBit_Image_Func                                            */ 
  /*                                                                       */ 
  /*                                                          */ 
  /*    Loads a given glyph sbit image from the font resource.  This also  */ 
  /*    returns its metrics.                                               */ 
  /*                                                                       */ 
  /*                                                                */ 
  /*    face        :: The target face object.                             */ 
  /*                                                                       */ 
  /*    x_ppem      :: The horizontal resolution in points per EM.         */ 
  /*                                                                       */ 
  /*    y_ppem      :: The vertical resolution in points per EM.           */ 
  /*                                                                       */ 
  /*    glyph_index :: The current glyph index.                            */ 
  /*                                                                       */ 
  /*    stream      :: The input stream.                                   */ 
  /*                                                                       */ 
  /* 
                                                              */ 
  /*    amap        :: The target pixmap.                                  */ 
  /*                                                                       */ 
  /*    ametrics    :: A big sbit metrics structure for the glyph image.   */ 
  /*                                                                       */ 
  /*                                                               */ 
  /*    FreeType error code.  0 means success.  Returns an error if no     */ 
  /*    glyph sbit exists for the index.                                   */ 
  /*                                                                       */ 
  /*                                                                 */ 
  /*    The `map.buffer' field is always freed before the glyph is loaded. */ 
  /*                                                                       */ 
  typedef FT_Error 
  (*TT_Load_SBit_Image_Func)( TT_Face              face, 
                              FT_ULong             strike_index, 
                              FT_UInt              glyph_index, 
                              FT_UInt              load_flags, 
                              FT_Stream            stream, 
                              FT_Bitmap           *amap, 
                              TT_SBit_MetricsRec  *ametrics ); 
 
 
  /*************************************************************************/ 
  /*                                                                       */ 
  /*                                                             */ 
  /*    TT_Set_SBit_Strike_Func                                            */ 
  /*                                                                       */ 
  /*                                                          */ 
  /*    Selects an sbit strike for given horizontal and vertical ppem      */ 
  /*    values.                                                            */ 
  /*                                                                       */ 
  /*                                                                */ 
  /*    face          :: The target face object.                           */ 
  /*                                                                       */ 
  /*    x_ppem        :: The horizontal resolution in points per EM.       */ 
  /*                                                                       */ 
  /*    y_ppem        :: The vertical resolution in points per EM.         */ 
  /*                                                                       */ 
  /* 
                                                              */ 
  /*    astrike_index :: The index of the sbit strike.                     */ 
  /*                                                                       */ 
  /*                                                               */ 
  /*    FreeType error code.  0 means success.  Returns an error if no     */ 
  /*    sbit strike exists for the selected ppem values.                   */ 
  /*                                                                       */ 
  typedef FT_Error 
  (*TT_Set_SBit_Strike_Func)( TT_Face    face, 
                              FT_Int     x_ppem, 
                              FT_Int     y_ppem, 
                              FT_ULong  *astrike_index ); 
 
 
  /*************************************************************************/ 
  /*                                                                       */ 
  /*                                                             */ 
  /*    TT_Get_PS_Name_Func                                                */ 
  /*                                                                       */ 
  /*                                                          */ 
  /*    Gets the PostScript glyph name of a glyph.                         */ 
  /*                                                                       */ 
  /*                                                                */ 
  /*    idx  :: The glyph index.                                           */ 
  /*                                                                       */ 
  /*    PSname :: The address of a string pointer.  Will be NULL in case   */ 
  /*              of error, otherwise it is a pointer to the glyph name.   */ 
  /*                                                                       */ 
  /*              You must not modify the returned string!                 */ 
  /*                                                                       */ 
  /* 
                                                              */ 
  /*    FreeType error code.  0 means success.                             */ 
  /*                                                                       */ 
  typedef FT_Error 
  (*TT_Get_PS_Name_Func)( TT_Face      face, 
                          FT_UInt      idx, 
                          FT_String**  PSname ); 
 
 
  /*************************************************************************/ 
  /*                                                                       */ 
  /*                                                             */ 
  /*    TT_Load_Metrics_Func                                               */ 
  /*                                                                       */ 
  /*                                                          */ 
  /*    Loads the horizontal or vertical header in a face object.          */ 
  /*                                                                       */ 
  /*                                                                */ 
  /*    face     :: A handle to the target face object.                    */ 
  /*                                                                       */ 
  /*    stream   :: The input stream.                                      */ 
  /*                                                                       */ 
  /*    vertical :: A boolean flag.  If set, load vertical metrics.        */ 
  /*                                                                       */ 
  /*                                                               */ 
  /*    FreeType error code.  0 means success.                             */ 
  /*                                                                       */ 
  typedef FT_Error 
  (*TT_Load_Metrics_Func)( TT_Face    face, 
                           FT_Stream  stream, 
                           FT_Bool    vertical ); 
 
 
  /*************************************************************************/ 
  /*                                                                       */ 
  /*                                                             */ 
  /*    TT_CharMap_Load_Func                                               */ 
  /*                                                                       */ 
  /*                                                          */ 
  /*    Loads a given TrueType character map into memory.                  */ 
  /*                                                                       */ 
  /*                                                                */ 
  /*    face   :: A handle to the parent face object.                      */ 
  /*                                                                       */ 
  /*    stream :: A handle to the current stream object.                   */ 
  /*                                                                       */ 
  /*                                                                */ 
  /*    cmap   :: A pointer to a cmap object.                              */ 
  /*                                                                       */ 
  /*                                                               */ 
  /*    FreeType error code.  0 means success.                             */ 
  /*                                                                       */ 
  /*                                                                 */ 
  /*    The function assumes that the stream is already in use (i.e.,      */ 
  /*    opened).  In case of error, all partially allocated tables are     */ 
  /*    released.                                                          */ 
  /*                                                                       */ 
  typedef FT_Error 
  (*TT_CharMap_Load_Func)( TT_Face       face, 
                           TT_CMapTable  cmap, 
                           FT_Stream     input ); 
 
 
  /*************************************************************************/ 
  /*                                                                       */ 
  /*                                                             */ 
  /*    TT_CharMap_Free_Func                                               */ 
  /*                                                                       */ 
  /*                                                          */ 
  /*    Destroys a character mapping table.                                */ 
  /*                                                                       */ 
  /*                                                                */ 
  /*    face :: A handle to the parent face object.                        */ 
  /*                                                                       */ 
  /*    cmap :: A handle to a cmap object.                                 */ 
  /*                                                                       */ 
  /*                                                               */ 
  /*    FreeType error code.  0 means success.                             */ 
  /*                                                                       */ 
  typedef FT_Error 
  (*TT_CharMap_Free_Func)( TT_Face       face, 
                           TT_CMapTable  cmap ); 
 
 
  /*************************************************************************/ 
  /*                                                                       */ 
  /*                                                             */ 
  /*    TT_Load_Table_Func                                                 */ 
  /*                                                                       */ 
  /*                                                          */ 
  /*    Loads a given TrueType table.                                      */ 
  /*                                                                       */ 
  /*                                                                */ 
  /*    face   :: A handle to the target face object.                      */ 
  /*                                                                       */ 
  /*    stream :: The input stream.                                        */ 
  /*                                                                       */ 
  /*                                                               */ 
  /*    FreeType error code.  0 means success.                             */ 
  /*                                                                       */ 
  /*                                                                 */ 
  /*    The function will use `face->goto_table' to seek the stream to     */ 
  /*    the start of the table.                                            */ 
  /*                                                                       */ 
  typedef FT_Error 
  (*TT_Load_Table_Func)( TT_Face    face, 
                         FT_Stream  stream ); 
 
 
  /*************************************************************************/ 
  /*                                                                       */ 
  /*                                                             */ 
  /*    TT_Free_Table_Func                                                 */ 
  /*                                                                       */ 
  /*                                                          */ 
  /*    Frees a given TrueType table.                                      */ 
  /*                                                                       */ 
  /*                                                                */ 
  /*    face :: A handle to the target face object.                        */ 
  /*                                                                       */ 
  typedef void 
  (*TT_Free_Table_Func)( TT_Face  face ); 
 
 
  /*************************************************************************/ 
  /*                                                                       */ 
  /*                                                             */ 
  /*    SFNT_Load_Table_Func                                               */ 
  /*                                                                       */ 
  /*                                                          */ 
  /*    Loads a given SFNT table in memory                                 */ 
  /*                                                                       */ 
  typedef FT_Error 
  (*SFNT_Load_Table_Func)( FT_Face      face, 
                           FT_ULong     tag, 
                           FT_Long      offset, 
                           FT_Byte*     buffer, 
                           FT_ULong*    length ); 
 
  /*************************************************************************/ 
  /*                                                                       */ 
  /*                                                               */ 
  /*    SFNT_Interface                                                     */ 
  /*                                                                       */ 
  /*                                                          */ 
  /*    This structure holds pointers to the functions used to load and    */ 
  /*    free the basic tables that are required in a `sfnt' font file.     */ 
  /*                                                                       */ 
  /*                                                               */ 
  /*    Check the various xxx_Func() descriptions for details.             */ 
  /*                                                                       */ 
  typedef struct  SFNT_Interface_ 
  { 
    TT_Loader_GotoTableFunc      goto_table; 
 
    TT_Init_Face_Func            init_face; 
    TT_Load_Face_Func            load_face; 
    TT_Done_Face_Func            done_face; 
    SFNT_Get_Interface_Func      get_interface; 
 
    TT_Load_Any_Func             load_any; 
    TT_Load_SFNT_HeaderRec_Func  load_sfnt_header; 
    TT_Load_Directory_Func       load_directory; 
 
    /* these functions are called by `load_face' but they can also  */ 
    /* be called from external modules, if there is a need to do so */ 
    TT_Load_Table_Func           load_header; 
    TT_Load_Metrics_Func         load_metrics; 
    TT_Load_Table_Func           load_charmaps; 
    TT_Load_Table_Func           load_max_profile; 
    TT_Load_Table_Func           load_os2; 
    TT_Load_Table_Func           load_psnames; 
 
    TT_Load_Table_Func           load_names; 
    TT_Free_Table_Func           free_names; 
 
    /* optional tables */ 
    TT_Load_Table_Func           load_hdmx; 
    TT_Free_Table_Func           free_hdmx; 
 
    TT_Load_Table_Func           load_kerning; 
    TT_Load_Table_Func           load_gasp; 
    TT_Load_Table_Func           load_pclt; 
 
    /* see `ttload.h' */ 
    TT_Load_Table_Func           load_bitmap_header; 
 
    /* see `ttsbit.h' */ 
    TT_Set_SBit_Strike_Func      set_sbit_strike; 
    TT_Load_Table_Func           load_sbits; 
    TT_Load_SBit_Image_Func      load_sbit_image; 
    TT_Free_Table_Func           free_sbits; 
 
    /* see `ttpost.h' */ 
    TT_Get_PS_Name_Func          get_psname; 
    TT_Free_Table_Func           free_psnames; 
 
    /* see `ttcmap.h' */ 
    TT_CharMap_Load_Func         load_charmap; 
    TT_CharMap_Free_Func         free_charmap; 
 
  } SFNT_Interface; 
 
 
  /* transitional */ 
  typedef SFNT_Interface*   SFNT_Service; 
 
 
FT_END_HEADER 
 
#endif /* __SFNT_H__ */ 
 
 
/* END */