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/***************************************************************************/
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/*                                                                         */
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/*  ftttdrv.h                                                              */
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/*                                                                         */
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/*    FreeType API for controlling the TrueType driver                     */
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/*    (specification only).                                                */
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/*                                                                         */
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/*  Copyright 2013 by                                                      */
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/*  David Turner, Robert Wilhelm, and Werner Lemberg.                      */
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/*                                                                         */
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/*  This file is part of the FreeType project, and may only be used,       */
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/*  modified, and distributed under the terms of the FreeType project      */
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/*  license, LICENSE.TXT.  By continuing to use, modify, or distribute     */
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/*  this file you indicate that you have read the license and              */
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/*  understand and accept it fully.                                        */
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/*                                                                         */
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/***************************************************************************/
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#ifndef __FTTTDRV_H__
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#define __FTTTDRV_H__
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#include
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#include FT_FREETYPE_H
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#ifdef FREETYPE_H
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#error "freetype.h of FreeType 1 has been loaded!"
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#error "Please fix the directory search order for header files"
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#error "so that freetype.h of FreeType 2 is found first."
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#endif
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FT_BEGIN_HEADER
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  /**************************************************************************
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   *
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   * @section:
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   *   tt_driver
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   *
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   * @title:
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   *   The TrueType driver
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   *
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   * @abstract:
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   *   Controlling the TrueType driver module.
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   *
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   * @description:
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   *   While FreeType's TrueType driver doesn't expose API functions by
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   *   itself, it is possible to control its behaviour with @FT_Property_Set
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   *   and @FT_Property_Get.  The following lists the available properties
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   *   together with the necessary macros and structures.
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   *
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   *   The TrueType driver's module name is `truetype'.
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   *
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   */
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  /**************************************************************************
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   *
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   * @property:
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   *   interpreter-version
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   *
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   * @description:
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   *   Currently, two versions are available which represent the bytecode
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   *   interpreter with and without subpixel hinting support,
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   *   respectively.  The default is subpixel support if
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   *   TT_CONFIG_OPTION_SUBPIXEL_HINTING is defined, and no subpixel
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   *   support otherwise (since it isn't available then).
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   *
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   *   If subpixel hinting is on, many TrueType bytecode instructions
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   *   behave differently compared to B/W or grayscale rendering.  The
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   *   main idea is to render at a much increased horizontal resolution,
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   *   then sampling down the created output to subpixel precision.
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   *   However, many older fonts are not suited to this and must be
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   *   specially taken care of by applying (hardcoded) font-specific
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   *   tweaks.
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   *
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   *   Details on subpixel hinting and some of the necessary tweaks can be
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   *   found in Greg Hitchcock's whitepaper at
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   *   `http://www.microsoft.com/typography/cleartype/truetypecleartype.aspx'.
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   *
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   *   The following example code demonstrates how to activate subpixel
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   *   hinting (omitting the error handling).
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   *
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   *   {
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   *     FT_Library  library;
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   *     FT_Face     face;
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   *     FT_UInt     interpreter_version = TT_INTERPRETER_VERSION_38;
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   *
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   *
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   *     FT_Init_FreeType( &library );
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   *
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   *     FT_Property_Set( library, "truetype",
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   *                               "interpreter-version",
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   *                               &interpreter_version );
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   *   }
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   *
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   * @note:
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   *   This property can be used with @FT_Property_Get also.
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   *
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   */
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  /**************************************************************************
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   *
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   * @enum:
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   *   TT_INTERPRETER_VERSION_XXX
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   *
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   * @description:
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   *   A list of constants used for the @interpreter-version property to
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   *   select the hinting engine for Truetype fonts.
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   *
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   *   The numeric value in the constant names represents the version
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   *   number as returned by the `GETINFO' bytecode instruction.
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   *
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   * @values:
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   *   TT_INTERPRETER_VERSION_35 ::
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   *     Version~35 corresponds to MS rasterizer v.1.7 as used e.g. in
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   *     Windows~98; only grayscale and B/W rasterizing is supported.
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   *
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   *   TT_INTERPRETER_VERSION_38 ::
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   *     Version~38 corresponds to MS rasterizer v.1.9; it is roughly
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   *     equivalent to the hinting provided by DirectWrite ClearType (as
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   *     can be found, for example, in the Internet Explorer~9 running on
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   *     Windows~7).
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   *
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   * @note:
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   *   This property controls the behaviour of the bytecode interpreter
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   *   and thus how outlines get hinted.  It does *not* control how glyph
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   *   get rasterized!  In particular, it does not control subpixel color
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   *   filtering.
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   *
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   *   If FreeType has not been compiled with configuration option
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   *   FT_CONFIG_OPTION_SUBPIXEL_HINTING, selecting version~38 causes an
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   *   `FT_Err_Unimplemented_Feature' error.
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   *
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   */
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#define TT_INTERPRETER_VERSION_35  35
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#define TT_INTERPRETER_VERSION_38  38
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 /* */
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FT_END_HEADER
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#endif /* __FTTTDRV_H__ */
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/* END */