ttapi.c

Qt/Embedded是一个多平台的C++图形用户界面应用程序框架

                                TT_ULong        fontIndex,
                                TT_Face*        aface )
  {
    if (!engine)
      return TT_Err_Invalid_Driver_Handle;

    return open_face( (FT_Library)engine, pathname, fontIndex, aface );
  }


  /***********************************************************************/
  /*                                                                     */
  /* <Function> TT_Close_Face                                            */
  /*                                                                     */
  /* <Description>                                                       */
  /*    Destroys a given face object opened through either TT_Open_Face  */
  /*    of TT_Open_Collection.                                           */
  /*                                                                     */
  /* <Input>                                                             */
  /*    face  :: handle to the target face object                        */
  /*                                                                     */
  /* <Return>                                                            */
  /*    TrueType error code. 0 means success                             */
  /*                                                                     */
  /* <MT-Note>                                                           */
  /*    No.                                                              */
  /*                                                                     */
  /* <Note>                                                              */
  /*    This API is provided for backwards compatibility. Please use     */
  /*    the functions TT_New_Face/TT_Done_Face now to create and         */
  /*    discard face/collection objects.                                 */
  /*                                                                     */

  EXPORT_DEF
  TT_Error  TT_Close_Face( TT_Face  face )
  {
    FT_Resource  resource;
    
    if (!face)
      return TT_Err_Invalid_Face_Handle;

    resource = face->root.resource;
    FT_Done_Face( (FT_Face)face );

    /* uninstall corresponding resource */
    FT_Done_Resource( resource );

    return TT_Err_Ok;
  }


  /***********************************************************************/
  /***********************************************************************/
  /***********************************************************************/
  /***********************************************************************/
  /***********                                                 ***********/
  /***********   End of backwards compatible APIs..            ***********/
  /***********                                                 ***********/
  /***********************************************************************/
  /***********************************************************************/
  /***********************************************************************/
  /***********************************************************************/


  /***********************************************************************/
  /*                                                                     */
  /* <Function> TT_Get_Face_Properties                                   */
  /*                                                                     */
  /* <Description>                                                       */
  /*    Return a given face's properties to the caller.                  */
  /*                                                                     */
  /* <Input>                                                             */
  /*    face  :: handle to the source face object                        */
  /*                                                                     */
  /* <Output>                                                            */
  /*    properties :: target properties structure                        */
  /*                                                                     */
  /* <Return>                                                            */
  /*    TrueType error code. 0 means success.                            */
  /*                                                                     */
  /* <MT-Note>                                                           */
  /*    Yes.                                                             */
  /*                                                                     */

  EXPORT_FUNC
  TT_Error  TT_Get_Face_Properties( TT_Face              face,
                                    TT_Face_Properties*  props )
  {
    props->num_Glyphs   = (TT_UShort)face->root.num_glyphs;
    props->max_Points   = (TT_UShort)face->root.max_points;
    props->max_Contours = (TT_UShort)face->root.max_contours;
    props->num_CharMaps = (TT_UShort)face->root.num_charmaps;
    props->num_Faces    = face->root.num_faces;
    props->num_Names    = face->num_names;
    props->header       = &face->header;
    props->horizontal   = &face->horizontal;
      
      /* The driver supports old Mac fonts where there are no OS/2  */
      /* tables present in the file. However, this is not true of   */
      /* FreeType 1.1. For the sake of backwards compatibility, we  */
      /* always return the address of the face's os2 table, even if */
      /* it is empty (in which case, the 'props.os2' field is set   */
      /* to NULL..                                                  */
      /*                                                            */
      /* Note however, that the 'os2->version' field is set to      */
      /* 0xFFFF to indicate a missing table though...               */
      /*                                                            */

    props->os2          = &face->os2;
      
    props->postscript    = &face->postscript;
    props->hdmx          = &face->hdmx;
    props->vertical      = ( face->vertical_info ? &face->vertical : 0 );

    return TT_Err_Ok;
  }


  /***********************************************************************/
  /*                                                                     */
  /* <Function> TT_Set_Face_Pointer.                                     */
  /*                                                                     */
  /* <Description>                                                       */
  /*    Each face object contains a typeless pointer, which use is left  */
  /*    to client applications (or the high-level library). This API is  */
  /*    used to set this generic pointer. It is ignored by the driver.   */
  /*                                                                     */
  /* <Input>                                                             */
  /*    face   :: target face object                                     */
  /*    data   :: generic pointer's value                                */
  /*                                                                     */
  /* <Return>                                                            */
  /*    TrueType error code. 0 means success                             */
  /*                                                                     */
  /* <MT-Note>                                                           */
  /*    No.                                                              */
  /*                                                                     */
  /* <Note>                                                              */
  /*    The generic pointer is used by the HLib when using the driver    */
  /*    within the FreeType library.                                     */
  /*                                                                     */

  EXPORT_FUNC
  TT_Error  TT_Set_Face_Pointer( TT_Face  face,
                                 void*    data )
  {
    if ( !face )
      return TT_Err_Invalid_Face_Handle;
    else
      face->root.generic.data = data;

    return TT_Err_Ok;
  }


  /***********************************************************************/
  /*                                                                     */
  /* <Function> TT_Get_Face_Pointer                                      */
  /*                                                                     */
  /* <Description>                                                       */
  /*    Each face object contains a typeless pointer, which use is left  */
  /*    to client applications (or the high-level library). This API is  */
  /*    used to retrieve this generic pointer, which is ignored by the   */
  /*    driver.                                                          */
  /*                                                                     */
  /* <Input>                                                             */
  /*    face    :: handle to source face object                          */
  /*                                                                     */
  /* <Return>                                                            */
  /*    generic pointer value. NULL if the face handle is invalid..      */
  /*                                                                     */
  /* <MT-Note>                                                           */
  /*    No.                                                              */
  /*                                                                     */

  EXPORT_FUNC
  void*  TT_Get_Face_Pointer( TT_Face  face )
  {
    return ( face ? face->root.generic.data : NULL );
  }

  /***********************************************************************/
  /*                                                                     */
  /* <Function> TT_Get_Face_Metrics                                      */
  /*                                                                     */
  /* <Description>                                                       */
  /*    Get the metrics of a given array of glyphs. Returns any number   */
  /*    of metrics arrays.                                               */
  /*                                                                     */
  /* <Input>                                                             */
  /*    face       :: handle to the source face object                   */
  /*    firstGlyph :: index of first glyph in the array                  */
  /*    lastGlyph  :: index of last glyph in the array                   */
  /*                                                                     */
  /* <Output>                                                            */
  /*    leftBearings :: target array of shorts for the glyph left side   */
  /*                    bearings. Set this field to NULL if you're not   */
  /*                    interested in these metrics.                     */
  /*                                                                     */
  /*    widths :: target array of unsigned shorts for the glyph advance  */
  /*              widths. Set this field to NULL if you're not           */
  /*              interested in these metrics.                           */
  /*                                                                     */
  /*    topBearings :: target array of shorts for the glyph top side     */
  /*                   bearings. Set this field to NULL if you're not    */
  /*                   interested in these metrics.                      */
  /*                                                                     */
  /*    heights :: target array of unsigned shorts for the glyph advance */
  /*               heights. Set this field to NULL if you're not         */
  /*               interested in these metrics.                          */
  /*                                                                     */
  /* <Return>                                                            */
  /*    TrueType error code. 0 means success.                            */
  /*                                                                     */
  /* <MT-Note>                                                           */
  /*    No.                                                              */
  /*                                                                     */

        /********************************************************/
        /* Return horizontal or vertical metrics in font units  */
        /* for a given glyph.  The metrics are the left side    */
        /* bearing (resp. top side bearing) and advance width   */
        /* (resp. advance height).                              */
        /*                                                      */
        /* This function will much probably move to another     */
        /* component in the short future, but I haven't decided */
        /* which yet...                                         */
    
          static
          void  get_metrics( TT_HoriHeader*  header,
                             TT_Int          index,
                             TT_Short*       bearing,
                             TT_UShort*      advance )
          {
            TT_LongMetrics*  longs_m;
    
            TT_UShort  k = header->number_Of_HMetrics;
    
    
            if ( index < k )
            {
              longs_m = (TT_LongMetrics*)header->long_metrics + index;
              *bearing = longs_m->bearing;
              *advance = longs_m->advance;
            }
            else
            {
              *bearing = ((TT_ShortMetrics*)header->short_metrics)[index - k];
              *advance = ((TT_LongMetrics*)header->long_metrics)[k - 1].advance;
            }
          }
    


  EXPORT_FUNC
  TT_Error  TT_Get_Face_Metrics( TT_Face     face,
                                 TT_UShort   firstGlyph,
                                 TT_UShort   lastGlyph,
                                 TT_Short*   leftBearings,
                                 TT_UShort*  widths,
                                 TT_Short*   topBearings,
                                 TT_UShort*  heights )
  {
    TT_UShort  num;

    if ( !face )
      return TT_Err_Invalid_Face_Handle;

    /* Check the glyph range */
    if ( lastGlyph >= face->root.num_glyphs || firstGlyph > lastGlyph )
      return TT_Err_Invalid_Argument;

    num = lastGlyph - firstGlyph;   /* number of elements-1 in each array */

    /* store the left side bearings and advance widths first */
    {
      TT_UShort  n;
      TT_Short   left_bearing;
      TT_UShort  advance_width;


      for ( n = 0; n <= num; n++ )
      {