freetype.h

a very goog book

  /*    An extremely simple structure used to model the size of a bitmap   */
  /*    strike (i.e., a bitmap instance of the font for a given            */
  /*    resolution) in a fixed-size font face.  This is used for the       */
  /*    `available_sizes' field of the FT_Face_Properties structure.       */
  /*                                                                       */
  /* <Fields>                                                              */
  /*    height :: The character height in pixels.                          */
  /*                                                                       */
  /*    width  :: The character width in pixels.                           */
  /*                                                                       */
  typedef struct  FT_Bitmap_Size_
  {
    FT_Short  height;
    FT_Short  width;

  } FT_Bitmap_Size;


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

  /*************************************************************************/
  /*                                                                       */
  /* <Type>                                                                */
  /*    FT_Library                                                         */
  /*                                                                       */
  /* <Description>                                                         */
  /*    A handle to a FreeType library instance.  Each `library' is        */
  /*    completely independent from the others; it is the `root' of a set  */
  /*    of objects like fonts, faces, sizes, etc.                          */
  /*                                                                       */
  /*    It also embeds a memory manager (see @FT_Memory), as well as a     */
  /*    scan-line converter object (see @FT_Raster).                       */
  /*                                                                       */
  /* <Note>                                                                */
  /*    Library objects are normally created by @FT_Init_FreeType, and     */
  /*    destroyed with @FT_Done_FreeType                                   */
  /*                                                                       */
  typedef struct FT_LibraryRec_  *FT_Library;


  /*************************************************************************/
  /*                                                                       */
  /* <Type>                                                                */
  /*    FT_Module                                                          */
  /*                                                                       */
  /* <Description>                                                         */
  /*    A handle to a given FreeType module object.  Each module can be a  */
  /*    font driver, a renderer, or anything else that provides services   */
  /*    to the formers.                                                    */
  /*                                                                       */
  typedef struct FT_ModuleRec_*  FT_Module;


  /*************************************************************************/
  /*                                                                       */
  /* <Type>                                                                */
  /*    FT_Driver                                                          */
  /*                                                                       */
  /* <Description>                                                         */
  /*    A handle to a given FreeType font driver object.  Each font driver */
  /*    is a special module capable of creating faces from font files.     */
  /*                                                                       */
  typedef struct FT_DriverRec_*  FT_Driver;


  /*************************************************************************/
  /*                                                                       */
  /* <Type>                                                                */
  /*    FT_Renderer                                                        */
  /*                                                                       */
  /* <Description>                                                         */
  /*    A handle to a given FreeType renderer.  A renderer is a special    */
  /*    module in charge of converting a glyph image to a bitmap, when     */
  /*    necessary.  Each renderer supports a given glyph image format, and */
  /*    one or more target surface depths.                                 */
  /*                                                                       */
  typedef struct FT_RendererRec_*  FT_Renderer;


  /*************************************************************************/
  /*                                                                       */
  /* <Type>                                                                */
  /*    FT_Face                                                            */
  /*                                                                       */
  /* <Description>                                                         */
  /*    A handle to a given typographic face object.  A face object models */
  /*    a given typeface, in a given style.                                */
  /*                                                                       */
  /* <Note>                                                                */
  /*    Each face object also owns a single @FT_GlyphSlot object, as well  */
  /*    as one or more @FT_Size objects.                                   */
  /*                                                                       */
  /*    use @FT_New_Face or @FT_Open_Face to create a new face object from */
  /*    a given filepathname or a custom input stream.                     */
  /*                                                                       */
  /*    use @FT_Done_Face to destroy it (along with its slot and sizes)    */
  /*                                                                       */
  /* <Also>                                                                */
  /*    the @FT_FaceRec details the publicly accessible fields of a given  */
  /*    face object.                                                       */
  /*                                                                       */
  typedef struct FT_FaceRec_*  FT_Face;


  /*************************************************************************/
  /*                                                                       */
  /* <Type>                                                                */
  /*    FT_Size                                                            */
  /*                                                                       */
  /* <Description>                                                         */
  /*    A handle to a given size object. Such an object models the         */
  /*    data that depends on the current _resolution_ and _character_      */
  /*    _size_ in a given @FT_Face.                                        */
  /*                                                                       */
  /* <Note>                                                                */
  /*    Each face object owns one or more sizes. There is however a        */
  /*    single _active_ size for the face at any time that will be         */
  /*    used by functions like @FT_Load_Glyph, @FT_Get_Kerning, etc...     */
  /*                                                                       */
  /*    you can use the @FT_Activate_Size API to change the current        */
  /*    active size of any given face                                      */
  /*                                                                       */
  /* <Also>                                                                */
  /*   the @FT_SizeRec structure details the publicly accessible fields    */
  /*   of a given face object.                                             */
  /*                                                                       */
  typedef struct FT_SizeRec_*  FT_Size;


  /*************************************************************************/
  /*                                                                       */
  /* <Type>                                                                */
  /*    FT_GlyphSlot                                                       */
  /*                                                                       */
  /* <Description>                                                         */
  /*    A handle to a given `glyph slot'.  A slot is a container where it  */
  /*    is possible to load any one of the glyphs contained in its parent  */
  /*    face.                                                              */
  /*                                                                       */
  /*    In other words, each time you call @FT_Load_Glyph or               */
  /*    @FT_Load_Char, the slot's content is erased by the new glyph data, */
  /*    i.e. the glyph's metrics, its image (bitmap or outline), and       */
  /*    other control information                                          */
  /*                                                                       */
  /* <Also>                                                                */
  /*    @FT_GlyphSlotRec details the publicly accessible glyph fields      */
  /*                                                                       */
  typedef struct FT_GlyphSlotRec_*  FT_GlyphSlot;


  /*************************************************************************/
  /*                                                                       */
  /* <Type>                                                                */
  /*    FT_CharMap                                                         */
  /*                                                                       */
  /* <Description>                                                         */
  /*    A handle to a given character map.  A charmap is used to translate */
  /*    character codes in a given encoding into glyph indexes for its     */
  /*    parent's face.  Some font formats may provide several charmaps per */
  /*    font.                                                              */
  /*                                                                       */
  /*    Each face object owns zero or more charmaps, but only one of       */
  /*    them can be "active" and used by @FT_Get_Char_Index or             */
  /*    @FT_Load_Char                                                      */
  /*                                                                       */
  /*    The list of available charmaps in a face is available through the  */
  /*    "face->num_charmaps" and "face->charmaps" fields of @FT_FaceRec    */
  /*                                                                       */
  /*    the currently active charmap is available as "face->charmap".      */
  /*    You should call @FT_Set_Charmap to change it                       */
  /*                                                                       */
  /* <Note>                                                                */
  /*    when a new face is created (either through @FT_New_Face or         */
  /*    @FT_Open_Face), the library looks for a Unicode charmap within     */
  /*    the list and automatically activates it                            */
  /*                                                                       */
  typedef struct FT_CharMapRec_*  FT_CharMap;


  /*************************************************************************/
  /*                                                                       */
  /* <Macro>                                                               */
  /*    FT_ENC_TAG                                                         */
  /*                                                                       */
  /* <Description>                                                         */
  /*    This macro converts four letter tags into an unsigned long.        */
  /*     It is used to define "encoding" identifiers (see @FT_Encoding)    */
  /*                                                                       */
  /*                                                                       */
#ifndef FT_ENC_TAG
#define FT_ENC_TAG( value, _x1, _x2, _x3, _x4 ) \
        value = ( ( (unsigned long)_x1 << 24 ) | \
                  ( (unsigned long)_x2 << 16 ) | \
                  ( (unsigned long)_x3 << 8  ) | \
                    (unsigned long)_x4         )
#endif /* FT_ENC_TAG */


  /*************************************************************************/
  /*                                                                       */
  /* <Enum>                                                                */