ttapi.c

Qt/Embedded是一个多平台的C++图形用户界面应用程序框架

        get_metrics( &face->horizontal,
                      firstGlyph + n, &left_bearing, &advance_width );

        if ( leftBearings )  leftBearings[n] = left_bearing;
        if ( widths )        widths[n]       = advance_width;
      }
    }

    /* check for vertical data if topBearings or heights is non-NULL */
    if ( !topBearings && !heights )
      return TT_Err_Ok;

    if ( !face->vertical_info )
      return TT_Err_No_Vertical_Data;

    /* store the top side bearings */
    {
      TT_UShort  n;
      TT_Short   top_bearing;
      TT_UShort  advance_height;

      for ( n = 0; n <= num; n++ )
      {
        get_metrics( (TT_HoriHeader*)&face->vertical,
                     firstGlyph + n, &top_bearing, &advance_height );

        if ( topBearings )  topBearings[n] = top_bearing;
        if ( heights )      heights[n]     = advance_height;
      }
    }

    return TT_Err_Ok;
  }


  /***********************************************************************/
  /*                                                                     */
  /* <Function> TT_New_Instance                                          */
  /*                                                                     */
  /* <Description>                                                       */
  /*    Creates a new instance object from a given face                  */
  /*                                                                     */
  /* <Input>                                                             */
  /*    face  :: handle to source/parent face object                     */
  /*                                                                     */
  /* <Output>                                                            */
  /*    instance :: handle to fresh object. Set to NULL in case of       */
  /*                error.                                               */
  /*                                                                     */
  /* <Return>                                                            */
  /*    TrueType error code. 0 means success                             */
  /*                                                                     */
  /* <MT-Note>                                                           */
  /*    Yes.                                                             */
  /*                                                                     */
  /* <Note>                                                              */
  /*    Any new instance uses a default resolution of 96x96 dpi, and     */
  /*    a default point size of 10 pts. You can change these anytime     */
  /*    with TT_Set_Instance_Resolutions/CharSize/CharSizes/PixelSizes   */
  /*    (see below).                                                     */
  /*                                                                     */

  EXPORT_FUNC
  TT_Error  TT_New_Instance( TT_Face       face,
                             TT_Instance*  instance )
  {
    return FT_New_Size( (FT_Face)face, (FT_Size*)instance );
  }


  /***********************************************************************/
  /*                                                                     */
  /* <Function> TT_Set_Instance_Resolutions                              */
  /*                                                                     */
  /* <Description>                                                       */
  /*    Sets an instance resolutions in dot-per-inches. Default values   */
  /*    for "new" instances are 96x96 dpi, but these can be changed any  */
  /*    time by calling this API.                                        */
  /*                                                                     */
  /* <Input>                                                             */
  /*    instance    :: handle to target instance object                  */
  /*    xResolution :: horizontal device resolution in dpi.              */
  /*    yResolution :: vertical device resolution in dpi.                */
  /*                                                                     */
  /* <Return>                                                            */
  /*    TrueType error code. 0 means success                             */
  /*                                                                     */
  /* <MT-Note>                                                           */
  /*    You should set the charsize or pixel size immediately after      */
  /*    call in multi-htreaded programs. This will force the instance    */
  /*    data to be resetted. Otherwise, you may encounter corruption     */
  /*    when loading two glyphs from the same instance concurrently!     */
  /*                                                                     */
  /*    Happily, 99.99% will do just that :-)                            */
  /*                                                                     */
  /*                                                                     */
  /*                                                                     */

  EXPORT_FUNC
  TT_Error  TT_Set_Instance_Resolutions( TT_Instance  ins,
                                         TT_UShort    xResolution,
                                         TT_UShort    yResolution )
  {
    return FT_Set_Resolutions( (FT_Size)ins, xResolution, yResolution );
  }

  /***********************************************************************/
  /*                                                                     */
  /* <Function> TT_Set_Instance_CharSizes                                */
  /*                                                                     */
  /* <Description>                                                       */
  /*    Same as TT_Set_Instance_CharSize, but used to specify distinct   */
  /*    horizontal and vertical coordinates.                             */
  /*                                                                     */
  /* <Input>                                                             */
  /*    instance   :: handle to target instance object                   */
  /*    charWidth  :: horizontal character size (26.6 points)            */
  /*    charHeight :: vertical character size (26.6 points)              */
  /*                                                                     */
  /* <Return>                                                            */
  /*    TrueType error code. 0 means success                             */
  /*                                                                     */
  /* <MT-Note>                                                           */
  /*    No.                                                              */
  /*                                                                     */
  /* <Note>                                                              */
  /*    There is no check for overflow; with other words, the product    */
  /*    of glyph dimensions times the device resolution must have        */
  /*    reasonable values.                                               */
  /*                                                                     */

  EXPORT_FUNC
  TT_Error  TT_Set_Instance_CharSizes( TT_Instance  ins,
                                       TT_F26Dot6   charWidth,
                                       TT_F26Dot6   charHeight )
  {
    return FT_Set_Char_Sizes( (FT_Size)ins, charWidth, charHeight );
  }


  /***********************************************************************/
  /*                                                                     */
  /* <Function> TT_Set_Instance_CharSize                                 */
  /*                                                                     */
  /* <Description>                                                       */
  /*    Sets an instance's character size. The size is in fractional     */
  /*    (26.6) point units. This function sets the horizontal and        */
  /*    vertical sizes to be equal. Use TT_Set_Instance_CharSizes        */
  /*    for distinct X and Y char sizes.                                 */
  /*                                                                     */
  /*    The default charsize of a new instance object is 10 pts.         */
  /*                                                                     */
  /* <Input>                                                             */
  /*    instance  :: handle to target instance object                    */
  /*    charSize  :: character size expressed in 26.6 fixed float        */
  /*                 points. 1 point = 1/72 dpi.                         */
  /*                                                                     */
  /* <Return>                                                            */
  /*    TrueType error code. 0 means success                             */
  /*                                                                     */
  /* <MT-Note>                                                           */
  /*    No.                                                              */
  /*                                                                     */

  EXPORT_FUNC
  TT_Error  TT_Set_Instance_CharSize( TT_Instance  instance,
                                      TT_F26Dot6   charSize )
  {
    return TT_Set_Instance_CharSizes( instance, charSize, charSize );
  }


  /***********************************************************************/
  /*                                                                     */
  /* <Function> TT_Set_Instance_PixelSizes                               */
  /*                                                                     */
  /* <Description>                                                       */
  /*    This function is used to set an instance's pixel sizes directly  */
  /*    It ignores the instance's resolutions fields, and you'll have to */
  /*    specify the corresponding pointsize in 26.6 fixed float point    */
  /*    units. The latter is a requirement of the TrueType bytecode      */
  /*    interpreter but can be ignored (or more safely, set to the       */
  /*    maximum pixel size multiplied by 64).                            */
  /*                                                                     */
  /* <Input>                                                             */
  /*    instance    :: handle to target instance object                  */
  /*    pixelWidth  :: horizontal pixel width (integer value)            */
  /*    pixelHeight :: vertical pixel height (integer value)             */
  /*    pointSize   :: corresponding point size (26.6 points)            */
  /*                                                                     */
  /* <Return>                                                            */
  /*    TrueType error code. 0 means success.                            */
  /*                                                                     */
  /* <MT-Note>                                                           */
  /*   No.                                                               */
  /*                                                                     */

  EXPORT_FUNC
  TT_Error  TT_Set_Instance_PixelSizes( TT_Instance  ins,
                                        TT_UShort    pixelWidth,
                                        TT_UShort    pixelHeight,
                                        TT_F26Dot6   pointSize )
  {
    /* The point size is now ignored by the driver */
    (void)pointSize;
    
    return FT_Set_Pixel_Sizes( (FT_Size)ins, pixelWidth, pixelHeight );
  }

  /***********************************************************************/
  /*                                                                     */
  /* <Function> TT_Get_Instance_Metrics                                  */
  /*                                                                     */
  /* <Description>                                                       */
  /*    Returns an instance's metrics into caller space.                 */
  /*                                                                     */
  /* <Input>                                                             */
  /*    instance  :: handle to source instance object                    */
  /*                                                                     */
  /* <Output>                                                            */
  /*    metrics   :: target instance metrics structure                   */
  /*                                                                     */
  /* <Return>                                                            */
  /*    TrueType error code. 0 means success                             */
  /*                                                                     */
  /* <MT-Note>                                                           */
  /*    No.                                                              */
  /*                                                                     */
  /* <Note>                                                              */
  /*    The TT_Instance_Metrics structure differs slightly from the      */
  /*    FT_Instance_Metrics one, which is why we re-implement this       */
  /*    function, rather than call a driver method for this..            */
  /*                                                                     */

  EXPORT_FUNC
  TT_Error  TT_Get_Instance_Metrics( TT_Instance           ins,
                                     TT_Instance_Metrics*  metrics )
  {
    TT_Size  size = (TT_Size)ins;

    if (!ins)
      return TT_Err_Invalid_Instance_Handle;

    metrics->x_scale      = size->root.metrics.x_scale;
    metrics->y_scale      = size->root.metrics.y_scale;
    metrics->x_resolution = size->root.metrics.x_resolution;
    metrics->y_resolution = size->root.metrics.y_resolution;
    metrics->x_ppem       = size->root.metrics.x_ppem;
    metrics->y_ppem       = size->root.metrics.y_ppem;

    metrics->pointSize    = size->root.metrics.pointSize;    
    return TT_Err_Ok;
  }


  /***********************************************************************/
  /*                                                                     */
  /* <Function> TT_Set_Instance_Pointer                                  */
  /*                                                                     */
  /* <Description>                                                       */
  /*    Each instance 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>                                                             */
  /*    instance  :: handle to the target instance object                */
  /*    data      :: value of the generic pointer                        */
  /*                                                                     */
  /* <Return>                                                            */
  /*    TrueType error code. 0 means success                             */
  /*                                                                     */
  /* <MT-Note>                                                           */
  /*    No.                                                              */
  /*                                                                     */

  EXPORT_FUNC
  TT_Error  TT_Set_Instance_Pointer( TT_Instance  ins,
                                     void*        data )
  {
    if ( !ins )
      return TT_Err_Invalid_Instance_Handle;
    else