git.r.bdr.sh - rbdr/super-polarity/blob

   1 /***************************************************************************/
   2 /*                                                                         */
   3 /*  ftgasp.h                                                               */
   4 /*                                                                         */
   5 /*    Access of TrueType's `gasp' table (specification).                   */
   6 /*                                                                         */
   7 /*  Copyright 2007, 2008, 2011 by                                          */
   8 /*  David Turner, Robert Wilhelm, and Werner Lemberg.                      */
   9 /*                                                                         */
  10 /*  This file is part of the FreeType project, and may only be used,       */
  11 /*  modified, and distributed under the terms of the FreeType project      */
  12 /*  license, LICENSE.TXT.  By continuing to use, modify, or distribute     */
  13 /*  this file you indicate that you have read the license and              */
  14 /*  understand and accept it fully.                                        */
  15 /*                                                                         */
  16 /***************************************************************************/
  17
  18
  19 #ifndef _FT_GASP_H_
  20 #define _FT_GASP_H_
  21
  22 #include <ft2build.h>
  23 #include FT_FREETYPE_H
  24
  25 #ifdef FREETYPE_H
  26 #error "freetype.h of FreeType 1 has been loaded!"
  27 #error "Please fix the directory search order for header files"
  28 #error "so that freetype.h of FreeType 2 is found first."
  29 #endif
  30
  31
  32   /***************************************************************************
  33    *
  34    * @section:
  35    *   gasp_table
  36    *
  37    * @title:
  38    *   Gasp Table
  39    *
  40    * @abstract:
  41    *   Retrieving TrueType `gasp' table entries.
  42    *
  43    * @description:
  44    *   The function @FT_Get_Gasp can be used to query a TrueType or OpenType
  45    *   font for specific entries in its `gasp' table, if any.  This is
  46    *   mainly useful when implementing native TrueType hinting with the
  47    *   bytecode interpreter to duplicate the Windows text rendering results.
  48    */
  49
  50   /*************************************************************************
  51    *
  52    * @enum:
  53    *   FT_GASP_XXX
  54    *
  55    * @description:
  56    *   A list of values and/or bit-flags returned by the @FT_Get_Gasp
  57    *   function.
  58    *
  59    * @values:
  60    *   FT_GASP_NO_TABLE ::
  61    *     This special value means that there is no GASP table in this face.
  62    *     It is up to the client to decide what to do.
  63    *
  64    *   FT_GASP_DO_GRIDFIT ::
  65    *     Grid-fitting and hinting should be performed at the specified ppem.
  66    *     This *really* means TrueType bytecode interpretation.  If this bit
  67    *     is not set, no hinting gets applied.
  68    *
  69    *   FT_GASP_DO_GRAY ::
  70    *     Anti-aliased rendering should be performed at the specified ppem.
  71    *     If not set, do monochrome rendering.
  72    *
  73    *   FT_GASP_SYMMETRIC_SMOOTHING ::
  74    *     If set, smoothing along multiple axes must be used with ClearType.
  75    *
  76    *   FT_GASP_SYMMETRIC_GRIDFIT ::
  77    *     Grid-fitting must be used with ClearType's symmetric smoothing.
  78    *
  79    * @note:
  80    *   The bit-flags `FT_GASP_DO_GRIDFIT' and `FT_GASP_DO_GRAY' are to be
  81    *   used for standard font rasterization only.  Independently of that,
  82    *   `FT_GASP_SYMMETRIC_SMOOTHING' and `FT_GASP_SYMMETRIC_GRIDFIT' are to
  83    *   be used if ClearType is enabled (and `FT_GASP_DO_GRIDFIT' and
  84    *   `FT_GASP_DO_GRAY' are consequently ignored).
  85    *
  86    *   `ClearType' is Microsoft's implementation of LCD rendering, partly
  87    *   protected by patents.
  88    *
  89    * @since:
  90    *   2.3.0
  91    */
  92 #define FT_GASP_NO_TABLE               -1
  93 #define FT_GASP_DO_GRIDFIT           0x01
  94 #define FT_GASP_DO_GRAY              0x02
  95 #define FT_GASP_SYMMETRIC_SMOOTHING  0x08
  96 #define FT_GASP_SYMMETRIC_GRIDFIT    0x10
  97
  98
  99   /*************************************************************************
 100    *
 101    * @func:
 102    *   FT_Get_Gasp
 103    *
 104    * @description:
 105    *   Read the `gasp' table from a TrueType or OpenType font file and
 106    *   return the entry corresponding to a given character pixel size.
 107    *
 108    * @input:
 109    *   face :: The source face handle.
 110    *   ppem :: The vertical character pixel size.
 111    *
 112    * @return:
 113    *   Bit flags (see @FT_GASP_XXX), or @FT_GASP_NO_TABLE if there is no
 114    *   `gasp' table in the face.
 115    *
 116    * @since:
 117    *   2.3.0
 118    */
 119   FT_EXPORT( FT_Int )
 120   FT_Get_Gasp( FT_Face  face,
 121                FT_UInt  ppem );
 122
 123 /* */
 124
 125 #endif /* _FT_GASP_H_ */
 126
 127
 128 /* END */