freetype.h

a very goog book

  /*    FT_Encoding                                                        */
  /*                                                                       */
  /* <Description>                                                         */
  /*    An enumeration used to specify encodings supported by charmaps.    */
  /*    Used in the FT_Select_Charmap() API function.                      */
  /*                                                                       */
  /* <Note>                                                                */
  /*    Because of 32-bit charcodes defined in Unicode (i.e., surrogates), */
  /*    all character codes must be expressed as FT_Longs.                 */
  /*                                                                       */
  /*    Other encodings might be defined in the future.                    */
  /*                                                                       */
  typedef enum  FT_Encoding_
  {
    FT_ENC_TAG( ft_encoding_none, 0, 0, 0, 0 ),

    FT_ENC_TAG( ft_encoding_symbol,  's', 'y', 'm', 'b' ),
    FT_ENC_TAG( ft_encoding_unicode, 'u', 'n', 'i', 'c' ),
    FT_ENC_TAG( ft_encoding_latin_1, 'l', 'a', 't', '1' ),
    FT_ENC_TAG( ft_encoding_latin_2, 'l', 'a', 't', '2' ),
    FT_ENC_TAG( ft_encoding_sjis,    's', 'j', 'i', 's' ),
    FT_ENC_TAG( ft_encoding_gb2312,  'g', 'b', ' ', ' ' ),
    FT_ENC_TAG( ft_encoding_big5,    'b', 'i', 'g', '5' ),
    FT_ENC_TAG( ft_encoding_wansung, 'w', 'a', 'n', 's' ),
    FT_ENC_TAG( ft_encoding_johab,   'j', 'o', 'h', 'a' ),

    FT_ENC_TAG( ft_encoding_adobe_standard, 'A', 'D', 'O', 'B' ),
    FT_ENC_TAG( ft_encoding_adobe_expert,   'A', 'D', 'B', 'E' ),
    FT_ENC_TAG( ft_encoding_adobe_custom,   'A', 'D', 'B', 'C' ),

    FT_ENC_TAG( ft_encoding_apple_roman, 'a', 'r', 'm', 'n' )

  } FT_Encoding;


  /*************************************************************************/
  /*                                                                       */
  /* <Struct>                                                              */
  /*    FT_CharMapRec                                                      */
  /*                                                                       */
  /* <Description>                                                         */
  /*    The base charmap structure.                                        */
  /*                                                                       */
  /* <Fields>                                                              */
  /*    face        :: A handle to the parent face object.                 */
  /*                                                                       */
  /*    encoding    :: A @FT_Encoding tag identifying the charmap.  Use    */
  /*                   this with @FT_Select_Charmap().                     */
  /*                                                                       */
  /*    platform_id :: An ID number describing the platform for the        */
  /*                   following encoding ID.  This comes directly from    */
  /*                   the TrueType specification and should be emulated   */
  /*                   for other formats.                                  */
  /*                                                                       */
  /*    encoding_id :: A platform specific encoding number.  This also     */
  /*                   comes from the TrueType specification and should be */
  /*                   emulated similarly.                                 */
  /*                                                                       */
  typedef struct  FT_CharMapRec_
  {
    FT_Face      face;
    FT_Encoding  encoding;
    FT_UShort    platform_id;
    FT_UShort    encoding_id;

  } FT_CharMapRec;


  /*************************************************************************/
  /*************************************************************************/
  /*                                                                       */
  /*                 B A S E   O B J E C T   C L A S S E S                 */
  /*                                                                       */
  /*************************************************************************/
  /*************************************************************************/


  /*************************************************************************/
  /*                                                                       */
  /* <Type>                                                                */
  /*    FT_Face_Internal                                                   */
  /*                                                                       */
  /* <Description>                                                         */
  /*    An opaque handle to an FT_Face_InternalRec structure, used to      */
  /*    model private data of a given @FT_Face object.                     */
  /*                                                                       */
  /*    This structure might change between releases of FreeType 2 and are */
  /*    not generally available to client applications.                    */
  /*                                                                       */
  typedef struct FT_Face_InternalRec_*  FT_Face_Internal;


  /*************************************************************************/
  /*                                                                       */
  /*                       FreeType base face object                       */
  /*                                                                       */
  /* <Struct>                                                              */
  /*    FT_FaceRec                                                         */
  /*                                                                       */
  /* <Description>                                                         */
  /*    FreeType root face class structure.  A face object models the      */
  /*    resolution and point-size independent data found in a font file.   */
  /*                                                                       */
  /* <Fields>                                                              */
  /*    num_faces           :: In the case where the face is located in a  */
  /*                           collection (i.e., a file which embed        */
  /*                           several faces), this is the total number of */
  /*                           faces found in the resource.  1 by default. */
  /*                                                                       */
  /*    face_index          :: The index of the face in its font file.     */
  /*                           Usually, this is 0 for all normal font      */
  /*                           formats.  It can be more in the case of     */
  /*                           collections (which embed several fonts in a */
  /*                           single resource/file).                      */
  /*                                                                       */
  /*    face_flags          :: A set of bit flags that give important      */
  /*                           information about the face; see the         */
  /*                           FT_FACE_FLAG_XXX constants for details.     */
  /*                                                                       */
  /*    style_flags         :: A set of bit flags indicating the style of  */
  /*                           the face (i.e., italic, bold, underline,    */
  /*                           etc).                                       */
  /*                                                                       */
  /*    num_glyphs          :: The total number of glyphs in the face.     */
  /*                                                                       */
  /*    family_name         :: The face's family name.  This is an ASCII   */
  /*                           string, usually in English, which describes */
  /*                           the typeface's family (like `Times New      */
  /*                           Roman', `Bodoni', `Garamond', etc).  This   */
  /*                           is a least common denominator used to list  */
  /*                           fonts.  Some formats (TrueType & OpenType)  */
  /*                           provide localized and Unicode versions of   */
  /*                           this string.  Applications should use the   */
  /*                           format specific interface to access them.   */
  /*                                                                       */
  /*    style_name          :: The face's style name.  This is an ASCII    */
  /*                           string, usually in English, which describes */
  /*                           the typeface's style (like `Italic',        */
  /*                           `Bold', `Condensed', etc).  Not all font    */
  /*                           formats provide a style name, so this field */
  /*                           is optional, and can be set to NULL.  As    */
  /*                           for `family_name', some formats provide     */
  /*                           localized/Unicode versions of this string.  */
  /*                           Applications should use the format specific */
  /*                           interface to access them.                   */
  /*                                                                       */
  /*    num_fixed_sizes     :: The number of fixed sizes available in this */
  /*                           face.  This should be set to 0 for scalable */
  /*                           fonts, unless its face includes a complete  */
  /*                           set of glyphs (called a `strike') for the   */
  /*                           specified sizes.                            */
  /*                                                                       */
  /*    available_sizes     :: An array of sizes specifying the available  */
  /*                           bitmap/graymap sizes that are contained in  */
  /*                           in the font face. Should be set to NULL if  */
  /*                           the field `num_fixed_sizes' is set to 0.    */
  /*                                                                       */
  /*    num_charmaps        :: The total number of character maps in the   */
  /*                           face.                                       */
  /*                                                                       */
  /*    charmaps            :: A table of pointers to the face's charmaps. */
  /*                           Used to scan the list of available charmaps */
  /*                           -- this table might change after a call to  */
  /*                           @FT_Attach_File or @FT_Attach_Stream (e.g.  */
  /*                           when used to hook an additional encoding or */
  /*                           CMap to the face object).                   */
  /*                                                                       */
  /*    generic             :: A field reserved for client uses.  See the  */
  /*                           @FT_Generic type description.               */
  /*                                                                       */
  /*    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 positive, 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 */