michael@0: /***************************************************************************/
michael@0: /*                                                                         */
michael@0: /*  ftgasp.h                                                               */
michael@0: /*                                                                         */
michael@0: /*    Access of TrueType's `gasp' table (specification).                   */
michael@0: /*                                                                         */
michael@0: /*  Copyright 2007, 2008, 2011 by                                          */
michael@0: /*  David Turner, Robert Wilhelm, and Werner Lemberg.                      */
michael@0: /*                                                                         */
michael@0: /*  This file is part of the FreeType project, and may only be used,       */
michael@0: /*  modified, and distributed under the terms of the FreeType project      */
michael@0: /*  license, LICENSE.TXT.  By continuing to use, modify, or distribute     */
michael@0: /*  this file you indicate that you have read the license and              */
michael@0: /*  understand and accept it fully.                                        */
michael@0: /*                                                                         */
michael@0: /***************************************************************************/
michael@0: 
michael@0: 
michael@0: #ifndef _FT_GASP_H_
michael@0: #define _FT_GASP_H_
michael@0: 
michael@0: #include <ft2build.h>
michael@0: #include FT_FREETYPE_H
michael@0: 
michael@0: #ifdef FREETYPE_H
michael@0: #error "freetype.h of FreeType 1 has been loaded!"
michael@0: #error "Please fix the directory search order for header files"
michael@0: #error "so that freetype.h of FreeType 2 is found first."
michael@0: #endif
michael@0: 
michael@0: 
michael@0:   /***************************************************************************
michael@0:    *
michael@0:    * @section:
michael@0:    *   gasp_table
michael@0:    *
michael@0:    * @title:
michael@0:    *   Gasp Table
michael@0:    *
michael@0:    * @abstract:
michael@0:    *   Retrieving TrueType `gasp' table entries.
michael@0:    *
michael@0:    * @description:
michael@0:    *   The function @FT_Get_Gasp can be used to query a TrueType or OpenType
michael@0:    *   font for specific entries in its `gasp' table, if any.  This is
michael@0:    *   mainly useful when implementing native TrueType hinting with the
michael@0:    *   bytecode interpreter to duplicate the Windows text rendering results.
michael@0:    */
michael@0: 
michael@0:   /*************************************************************************
michael@0:    *
michael@0:    * @enum:
michael@0:    *   FT_GASP_XXX
michael@0:    *
michael@0:    * @description:
michael@0:    *   A list of values and/or bit-flags returned by the @FT_Get_Gasp
michael@0:    *   function.
michael@0:    *
michael@0:    * @values:
michael@0:    *   FT_GASP_NO_TABLE ::
michael@0:    *     This special value means that there is no GASP table in this face.
michael@0:    *     It is up to the client to decide what to do.
michael@0:    *
michael@0:    *   FT_GASP_DO_GRIDFIT ::
michael@0:    *     Grid-fitting and hinting should be performed at the specified ppem.
michael@0:    *     This *really* means TrueType bytecode interpretation.  If this bit
michael@0:    *     is not set, no hinting gets applied.
michael@0:    *
michael@0:    *   FT_GASP_DO_GRAY ::
michael@0:    *     Anti-aliased rendering should be performed at the specified ppem.
michael@0:    *     If not set, do monochrome rendering.
michael@0:    *
michael@0:    *   FT_GASP_SYMMETRIC_SMOOTHING ::
michael@0:    *     If set, smoothing along multiple axes must be used with ClearType.
michael@0:    *
michael@0:    *   FT_GASP_SYMMETRIC_GRIDFIT ::
michael@0:    *     Grid-fitting must be used with ClearType's symmetric smoothing.
michael@0:    *
michael@0:    * @note:
michael@0:    *   The bit-flags `FT_GASP_DO_GRIDFIT' and `FT_GASP_DO_GRAY' are to be
michael@0:    *   used for standard font rasterization only.  Independently of that,
michael@0:    *   `FT_GASP_SYMMETRIC_SMOOTHING' and `FT_GASP_SYMMETRIC_GRIDFIT' are to
michael@0:    *   be used if ClearType is enabled (and `FT_GASP_DO_GRIDFIT' and
michael@0:    *   `FT_GASP_DO_GRAY' are consequently ignored).
michael@0:    *
michael@0:    *   `ClearType' is Microsoft's implementation of LCD rendering, partly
michael@0:    *   protected by patents.
michael@0:    *
michael@0:    * @since:
michael@0:    *   2.3.0
michael@0:    */
michael@0: #define FT_GASP_NO_TABLE               -1
michael@0: #define FT_GASP_DO_GRIDFIT           0x01
michael@0: #define FT_GASP_DO_GRAY              0x02
michael@0: #define FT_GASP_SYMMETRIC_SMOOTHING  0x08
michael@0: #define FT_GASP_SYMMETRIC_GRIDFIT    0x10
michael@0: 
michael@0: 
michael@0:   /*************************************************************************
michael@0:    *
michael@0:    * @func:
michael@0:    *   FT_Get_Gasp
michael@0:    *
michael@0:    * @description:
michael@0:    *   Read the `gasp' table from a TrueType or OpenType font file and
michael@0:    *   return the entry corresponding to a given character pixel size.
michael@0:    *
michael@0:    * @input:
michael@0:    *   face :: The source face handle.
michael@0:    *   ppem :: The vertical character pixel size.
michael@0:    *
michael@0:    * @return:
michael@0:    *   Bit flags (see @FT_GASP_XXX), or @FT_GASP_NO_TABLE if there is no
michael@0:    *   `gasp' table in the face.
michael@0:    *
michael@0:    * @since:
michael@0:    *   2.3.0
michael@0:    */
michael@0:   FT_EXPORT( FT_Int )
michael@0:   FT_Get_Gasp( FT_Face  face,
michael@0:                FT_UInt  ppem );
michael@0: 
michael@0: /* */
michael@0: 
michael@0: #endif /* _FT_GASP_H_ */
michael@0: 
michael@0: 
michael@0: /* END */