freetype.h

winNT技术操作系统,国外开放的原代码和LIUX一样

  /*                                                                       */
  /* <Struct>                                                              */
  /*    FT_Glyph_Metrics                                                   */
  /*                                                                       */
  /* <Description>                                                         */
  /*    A structure used to model the metrics of a single glyph.  The      */
  /*    values are expressed in 26.6 fractional pixel format; if the flag  */
  /*    @FT_LOAD_NO_SCALE has been used while loading the glyph, values    */
  /*    are expressed in font units instead.                               */
  /*                                                                       */
  /* <Fields>                                                              */
  /*    width ::                                                           */
  /*      The glyph's width.                                               */
  /*                                                                       */
  /*    height ::                                                          */
  /*      The glyph's height.                                              */
  /*                                                                       */
  /*    horiBearingX ::                                                    */
  /*      Left side bearing for horizontal layout.                         */
  /*                                                                       */
  /*    horiBearingY ::                                                    */
  /*      Top side bearing for horizontal layout.                          */
  /*                                                                       */
  /*    horiAdvance ::                                                     */
  /*      Advance width for horizontal layout.                             */
  /*                                                                       */
  /*    vertBearingX ::                                                    */
  /*      Left side bearing for vertical layout.                           */
  /*                                                                       */
  /*    vertBearingY ::                                                    */
  /*      Top side bearing for vertical layout.                            */
  /*                                                                       */
  /*    vertAdvance ::                                                     */
  /*      Advance height for vertical layout.                              */
  /*                                                                       */
  typedef struct  FT_Glyph_Metrics_
  {
    FT_Pos  width;
    FT_Pos  height;

    FT_Pos  horiBearingX;
    FT_Pos  horiBearingY;
    FT_Pos  horiAdvance;

    FT_Pos  vertBearingX;
    FT_Pos  vertBearingY;
    FT_Pos  vertAdvance;

  } FT_Glyph_Metrics;


  /*************************************************************************/
  /*                                                                       */
  /* <Struct>                                                              */
  /*    FT_Bitmap_Size                                                     */
  /*                                                                       */
  /* <Description>                                                         */
  /*    This structure models the metrics of a bitmap strike (i.e., a set  */
  /*    of glyphs for a given point size and resolution) in a bitmap font. */
  /*    It is used for the `available_sizes' field of @FT_Face.            */
  /*                                                                       */
  /* <Fields>                                                              */
  /*    height :: The vertical distance, in pixels, between two            */
  /*              consecutive baselines.  It is always positive.           */
  /*                                                                       */
  /*    width  :: The average width, in pixels, of all glyphs in the       */
  /*              strike.                                                  */
  /*                                                                       */
  /*    size   :: The nominal size of the strike in 26.6 fractional        */
  /*              points.  This field is not very useful.                  */
  /*                                                                       */
  /*    x_ppem :: The horizontal ppem (nominal width) in 26.6 fractional   */
  /*              pixels.                                                  */
  /*                                                                       */
  /*    y_ppem :: The vertical ppem (nominal height) in 26.6 fractional    */
  /*              pixels.                                                  */
  /*                                                                       */
  /* <Note>                                                                */
  /*    Windows FNT:                                                       */
  /*      The nominal size given in a FNT font is not reliable.  Thus when */
  /*      the driver finds it incorrect, it sets `size' to some calculated */
  /*      values and sets `x_ppem' and `y_ppem' to the pixel width and     */
  /*      height given in the font, respectively.                          */
  /*                                                                       */
  /*    TrueType embedded bitmaps:                                         */
  /*      `size', `width', and `height' values are not contained in the    */
  /*      bitmap strike itself.  They are computed from the global font    */
  /*      parameters.                                                      */
  /*                                                                       */
  typedef struct  FT_Bitmap_Size_
  {
    FT_Short  height;
    FT_Short  width;

    FT_Pos    size;

    FT_Pos    x_ppem;
    FT_Pos    y_ppem;

  } 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).                       */
  /*                                                                       */
  /*    For multi-threading applications each thread should have its own   */
  /*    FT_Library object.                                                 */
  /*                                                                       */
  /* <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;