misc/libfreetype/include/freetype/ftgasp.h
changeset 5172 88f2e05288ba
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/misc/libfreetype/include/freetype/ftgasp.h	Mon Apr 25 01:46:54 2011 +0200
@@ -0,0 +1,128 @@
+/***************************************************************************/
+/*                                                                         */
+/*  ftgasp.h                                                               */
+/*                                                                         */
+/*    Access of TrueType's `gasp' table (specification).                   */
+/*                                                                         */
+/*  Copyright 2007, 2008, 2011 by                                          */
+/*  David Turner, Robert Wilhelm, and Werner Lemberg.                      */
+/*                                                                         */
+/*  This file is part of the FreeType project, and may only be used,       */
+/*  modified, and distributed under the terms of the FreeType project      */
+/*  license, LICENSE.TXT.  By continuing to use, modify, or distribute     */
+/*  this file you indicate that you have read the license and              */
+/*  understand and accept it fully.                                        */
+/*                                                                         */
+/***************************************************************************/
+
+
+#ifndef _FT_GASP_H_
+#define _FT_GASP_H_
+
+#include <ft2build.h>
+#include FT_FREETYPE_H
+
+#ifdef FREETYPE_H
+#error "freetype.h of FreeType 1 has been loaded!"
+#error "Please fix the directory search order for header files"
+#error "so that freetype.h of FreeType 2 is found first."
+#endif
+
+
+  /***************************************************************************
+   *
+   * @section:
+   *   gasp_table
+   *
+   * @title:
+   *   Gasp Table
+   *
+   * @abstract:
+   *   Retrieving TrueType `gasp' table entries.
+   *
+   * @description:
+   *   The function @FT_Get_Gasp can be used to query a TrueType or OpenType
+   *   font for specific entries in its `gasp' table, if any.  This is
+   *   mainly useful when implementing native TrueType hinting with the
+   *   bytecode interpreter to duplicate the Windows text rendering results.
+   */
+
+  /*************************************************************************
+   *
+   * @enum:
+   *   FT_GASP_XXX
+   *
+   * @description:
+   *   A list of values and/or bit-flags returned by the @FT_Get_Gasp
+   *   function.
+   *
+   * @values:
+   *   FT_GASP_NO_TABLE ::
+   *     This special value means that there is no GASP table in this face.
+   *     It is up to the client to decide what to do.
+   *
+   *   FT_GASP_DO_GRIDFIT ::
+   *     Grid-fitting and hinting should be performed at the specified ppem. 
+   *     This *really* means TrueType bytecode interpretation.  If this bit
+   *     is not set, no hinting gets applied.
+   *
+   *   FT_GASP_DO_GRAY ::
+   *     Anti-aliased rendering should be performed at the specified ppem. 
+   *     If not set, do monochrome rendering.
+   *
+   *   FT_GASP_SYMMETRIC_SMOOTHING ::
+   *     If set, smoothing along multiple axes must be used with ClearType.
+   *
+   *   FT_GASP_SYMMETRIC_GRIDFIT ::
+   *     Grid-fitting must be used with ClearType's symmetric smoothing.
+   *
+   * @note:
+   *   The bit-flags `FT_GASP_DO_GRIDFIT' and `FT_GASP_DO_GRAY' are to be
+   *   used for standard font rasterization only.  Independently of that,
+   *   `FT_GASP_SYMMETRIC_SMOOTHING' and `FT_GASP_SYMMETRIC_GRIDFIT' are to
+   *   be used if ClearType is enabled (and `FT_GASP_DO_GRIDFIT' and
+   *   `FT_GASP_DO_GRAY' are consequently ignored).
+   *
+   *   `ClearType' is Microsoft's implementation of LCD rendering, partly
+   *   protected by patents.
+   *
+   * @since:
+   *   2.3.0
+   */
+#define FT_GASP_NO_TABLE               -1
+#define FT_GASP_DO_GRIDFIT           0x01
+#define FT_GASP_DO_GRAY              0x02
+#define FT_GASP_SYMMETRIC_SMOOTHING  0x08
+#define FT_GASP_SYMMETRIC_GRIDFIT    0x10
+
+
+  /*************************************************************************
+   *
+   * @func:
+   *   FT_Get_Gasp
+   *
+   * @description:
+   *   Read the `gasp' table from a TrueType or OpenType font file and
+   *   return the entry corresponding to a given character pixel size.
+   *
+   * @input:
+   *   face :: The source face handle.
+   *   ppem :: The vertical character pixel size.
+   *
+   * @return:
+   *   Bit flags (see @FT_GASP_XXX), or @FT_GASP_NO_TABLE if there is no
+   *   `gasp' table in the face.
+   *
+   * @since:
+   *   2.3.0
+   */
+  FT_EXPORT( FT_Int )
+  FT_Get_Gasp( FT_Face  face,
+               FT_UInt  ppem );
+
+/* */
+
+#endif /* _FT_GASP_H_ */
+
+
+/* END */