freetype.h

下载来的一个看图软件的源代码

  /*                                                                       */
  /*    bbox                :: The font bounding box.  Coordinates are     */
  /*                           expressed in font units (see units_per_EM). */
  /*                           The box is large enough to contain any      */
  /*                           glyph from the font.  Thus, bbox.yMax can   */
  /*                           be seen as the `maximal ascender',          */
  /*                           bbox.yMin as the `minimal descender', and   */
  /*                           the maximal glyph width is given by         */
  /*                           `bbox.xMax-bbox.xMin' (not to be confused   */
  /*                           with the maximal _advance_width_).  Only    */
  /*                           relevant for scalable formats.              */
  /*                                                                       */
  /*    units_per_EM        :: The number of font units per EM square for  */
  /*                           this face.  This is typically 2048 for      */
  /*                           TrueType fonts, 1000 for Type1 fonts, and   */
  /*                           should be set to the (unrealistic) value 1  */
  /*                           for fixed-sizes fonts.  Only relevant for   */
  /*                           scalable formats.                           */
  /*                                                                       */
  /*    ascender            :: The face's ascender is the vertical         */
  /*                           distance from the baseline to the topmost   */
  /*                           point of any glyph in the face.  This       */
  /*                           field's value is positive, expressed in     */
  /*                           font units.  Some font designs use a value  */
  /*                           different from `bbox.yMax'.  Only relevant  */
  /*                           for scalable formats.                       */
  /*                                                                       */
  /*    descender           :: The face's descender is the vertical        */
  /*                           distance from the baseline to the           */
  /*                           bottommost point of any glyph in the face.  */
  /*                           This field's value is *negative* for values */
  /*                           below the baseline.  It is expressed in     */
  /*                           font units.  Some font designs use a value  */
  /*                           different from `bbox.yMin'.  Only relevant  */
  /*                           for scalable formats.                       */
  /*                                                                       */
  /*    height              :: The face's height is the vertical distance  */
  /*                           from one baseline to the next when writing  */
  /*                           several lines of text.  Its value is always */
  /*                           positive, expressed in font units.  The     */
  /*                           value can be computed as                    */
  /*                           `ascender+descender+line_gap' where the     */
  /*                           value of `line_gap' is also called          */
  /*                           `external leading'.  Only relevant for      */
  /*                           scalable formats.                           */
  /*                                                                       */
  /*    max_advance_width   :: The maximal advance width, in font units,   */
  /*                           for all glyphs in this face.  This can be   */
  /*                           used to make word wrapping computations     */
  /*                           faster.  Only relevant for scalable         */
  /*                           formats.                                    */
  /*                                                                       */
  /*    max_advance_height  :: The maximal advance height, in font units,  */
  /*                           for all glyphs in this face.  This is only  */
  /*                           relevant for vertical layouts, and should   */
  /*                           be set to the `height' for fonts that do    */
  /*                           not provide vertical metrics.  Only         */
  /*                           relevant for scalable formats.              */
  /*                                                                       */
  /*    underline_position  :: The position, in font units, of the         */
  /*                           underline line for this face.  It's the     */
  /*                           center of the underlining stem.  Only       */
  /*                           relevant for scalable formats.              */
  /*                                                                       */
  /*    underline_thickness :: The thickness, in font units, of the        */
  /*                           underline for this face.  Only relevant for */
  /*                           scalable formats.                           */
  /*                                                                       */
  /*    glyph               :: The face's associated glyph slot(s).  This  */
  /*                           object is created automatically with a new  */
  /*                           face object.  However, certain kinds of     */
  /*                           applications (mainly tools like converters) */
  /*                           can need more than one slot to ease their   */
  /*                           task.                                       */
  /*                                                                       */
  /*    size                :: The current active size for this face.      */
  /*                                                                       */
  /*    charmap             :: The current active charmap for this face.   */
  /*                                                                       */
  typedef struct  FT_FaceRec_
  {
    FT_Long           num_faces;
    FT_Long           face_index;

    FT_Long           face_flags;
    FT_Long           style_flags;

    FT_Long           num_glyphs;

    FT_String*        family_name;
    FT_String*        style_name;

    FT_Int            num_fixed_sizes;
    FT_Bitmap_Size*   available_sizes;

    FT_Int            num_charmaps;
    FT_CharMap*       charmaps;

    FT_Generic        generic;

    /*# the following are only relevant to scalable outlines */
    FT_BBox           bbox;

    FT_UShort         units_per_EM;
    FT_Short          ascender;
    FT_Short          descender;
    FT_Short          height;

    FT_Short          max_advance_width;
    FT_Short          max_advance_height;

    FT_Short          underline_position;
    FT_Short          underline_thickness;

    FT_GlyphSlot      glyph;
    FT_Size           size;
    FT_CharMap        charmap;

    /*@private begin */

    FT_Driver         driver;
    FT_Memory         memory;
    FT_Stream         stream;

    FT_ListRec        sizes_list;

    FT_Generic        autohint;
    void*             extensions;

    FT_Face_Internal  internal;

    /*@private end */

  } FT_FaceRec;


  /*************************************************************************/
  /*                                                                       */
  /* <Enum>                                                                */
  /*    FT_FACE_FLAG_XXX                                                   */
  /*                                                                       */
  /* <Description>                                                         */
  /*    A list of bit flags used in the 'face_flags' field of the          */
  /*    @FT_FaceRec structure.  They inform client applications of         */
  /*    properties of the corresponding face.                              */
  /*                                                                       */
  /* <Values>                                                              */
  /*    FT_FACE_FLAG_SCALABLE ::                                           */
  /*      Indicates that the face provides vectorial outlines.  This       */
  /*      doesn't prevent embedded bitmaps, i.e., a face can have both     */
  /*      this bit and @FT_FACE_FLAG_FIXED_SIZES set.                      */
  /*                                                                       */
  /*    FT_FACE_FLAG_FIXED_SIZES ::                                        */
  /*      Indicates that the face contains `fixed sizes', i.e., bitmap     */
  /*      strikes for some given pixel sizes.  See the `num_fixed_sizes'   */
  /*      and `available_sizes' fields of @FT_FaceRec.                     */
  /*                                                                       */
  /*    FT_FACE_FLAG_FIXED_WIDTH ::                                        */
  /*      Indicates that the face contains fixed-width characters (like    */
  /*      Courier, Lucido, MonoType, etc.).                                */
  /*                                                                       */
  /*    FT_FACE_FLAG_SFNT ::                                               */
  /*      Indicates that the face uses the `sfnt' storage scheme.  For     */
  /*      now, this means TrueType and OpenType.                           */
  /*                                                                       */
  /*    FT_FACE_FLAG_HORIZONTAL ::                                         */
  /*      Indicates that the face contains horizontal glyph metrics.  This */
  /*      should be set for all common formats.                            */
  /*                                                                       */
  /*    FT_FACE_FLAG_VERTICAL ::                                           */
  /*      Indicates that the face contains vertical glyph metrics.  This   */
  /*      is only available in some formats, not all of them.              */
  /*                                                                       */
  /*    FT_FACE_FLAG_KERNING ::                                            */
  /*      Indicates that the face contains kerning information.  If set,   */
  /*      the kerning distance can be retrieved through the function       */
  /*      @FT_Get_Kerning.  Note that if unset, this function will always  */
  /*      return the vector (0,0).                                         */
  /*                                                                       */
  /*    FT_FACE_FLAG_FAST_GLYPHS ::                                        */
  /*      THIS FLAG IS DEPRECATED.  DO NOT USE OR TEST IT.                 */
  /*                                                                       */
  /*    FT_FACE_FLAG_MULTIPLE_MASTERS ::                                   */
  /*      Indicates that the font contains multiple masters and is capable */
  /*      of interpolating between them.  See the multiple-masters         */
  /*      specific API for details.                                        */
  /*                                                                       */
  /*    FT_FACE_FLAG_GLYPH_NAMES ::                                        */
  /*      Indicates that the font contains glyph names that can be         */
  /*      retrieved through @FT_Get_Glyph_Name.  Note that some TrueType   */
  /*      fonts contain broken glyph name tables.  Use the function        */
  /*      @FT_Has_PS_Glyph_Names when needed.                              */
  /*                                                                       */
  /*    FT_FACE_FLAG_EXTERNAL_STREAM ::                                    */
  /*      Used internal