Merge to XFA: Update bundled freetype to 2.6.1

third_party/freetype/include/ftlcdfil.h

Index: third_party/freetype/include/ftlcdfil.h
diff --git a/third_party/freetype/include/ftlcdfil.h b/third_party/freetype/include/ftlcdfil.h
deleted file mode 100644
index 39206f0192741b82836a3c66aa409f9074db9647..0000000000000000000000000000000000000000
--- a/third_party/freetype/include/ftlcdfil.h
+++ /dev/null
@@ -1,251 +0,0 @@
-/***************************************************************************/
-/*                                                                         */
-/*  ftlcdfil.h                                                             */
-/*                                                                         */
-/*    FreeType API for color filtering of subpixel bitmap glyphs           */
-/*    (specification).                                                     */
-/*                                                                         */
-/*  Copyright 2006-2008, 2010, 2013 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_LCD_FILTER_H__
-#define __FT_LCD_FILTER_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
-
-
-FT_BEGIN_HEADER
-
-  /***************************************************************************
-   *
-   * @section:
-   *   lcd_filtering
-   *
-   * @title:
-   *   LCD Filtering
-   *
-   * @abstract:
-   *   Reduce color fringes of LCD-optimized bitmaps.
-   *
-   * @description:
-   *   The @FT_Library_SetLcdFilter API can be used to specify a low-pass
-   *   filter, which is then applied to LCD-optimized bitmaps generated
-   *   through @FT_Render_Glyph.  This is useful to reduce color fringes
-   *   that would occur with unfiltered rendering.
-   *
-   *   Note that no filter is active by default, and that this function is
-   *   *not* implemented in default builds of the library.  You need to
-   *   #define FT_CONFIG_OPTION_SUBPIXEL_RENDERING in your `ftoption.h' file
-   *   in order to activate it.
-   *
-   *   FreeType generates alpha coverage maps, which are linear by nature.
-   *   For instance, the value 0x80 in bitmap representation means that
-   *   (within numerical precision) 0x80/0xff fraction of that pixel is
-   *   covered by the glyph's outline.  The blending function for placing
-   *   text over a background is
-   *
-   *   {
-   *     dst = alpha * src + (1 - alpha) * dst    ,
-   *   }
-   *
-   *   which is known as OVER.  However, when calculating the output of the
-   *   OVER operator, the source colors should first be transformed to a
-   *   linear color space, then alpha blended in that space, and transformed
-   *   back to the output color space.
-   *
-   *   When linear light blending is used, the default FIR5 filtering
-   *   weights (as given by FT_LCD_FILTER_DEFAULT) are no longer optimal, as
-   *   they have been designed for black on white rendering while lacking
-   *   gamma correction.  To preserve color neutrality, weights for a FIR5
-   *   filter should be chosen according to two free parameters `a' and `c',
-   *   and the FIR weights should be
-   *
-   *   {
-   *     [a - c, a + c, 2 * a, a + c, a - c]    .
-   *   }
-   *
-   *   This formula generates equal weights for all the color primaries
-   *   across the filter kernel, which makes it colorless.  One suggested
-   *   set of weights is
-   *
-   *   {
-   *     [0x10, 0x50, 0x60, 0x50, 0x10]    ,
-   *   }
-   *
-   *   where `a' has value 0x30 and `b' value 0x20.  The weights in filter
-   *   may have a sum larger than 0x100, which increases coloration slightly
-   *   but also improves contrast.
-   */
-
-
-  /****************************************************************************
-   *
-   * @enum:
-   *   FT_LcdFilter
-   *
-   * @description:
-   *   A list of values to identify various types of LCD filters.
-   *
-   * @values:
-   *   FT_LCD_FILTER_NONE ::
-   *     Do not perform filtering.  When used with subpixel rendering, this
-   *     results in sometimes severe color fringes.
-   *
-   *   FT_LCD_FILTER_DEFAULT ::
-   *     The default filter reduces color fringes considerably, at the cost
-   *     of a slight blurriness in the output.
-   *
-   *   FT_LCD_FILTER_LIGHT ::
-   *     The light filter is a variant that produces less blurriness at the
-   *     cost of slightly more color fringes than the default one.  It might
-   *     be better, depending on taste, your monitor, or your personal vision.
-   *
-   *   FT_LCD_FILTER_LEGACY ::
-   *     This filter corresponds to the original libXft color filter.  It
-   *     provides high contrast output but can exhibit really bad color
-   *     fringes if glyphs are not extremely well hinted to the pixel grid.
-   *     In other words, it only works well if the TrueType bytecode
-   *     interpreter is enabled *and* high-quality hinted fonts are used.
-   *
-   *     This filter is only provided for comparison purposes, and might be
-   *     disabled or stay unsupported in the future.
-   *
-   * @since:
-   *   2.3.0
-   */
-  typedef enum  FT_LcdFilter_
-  {
-    FT_LCD_FILTER_NONE    = 0,
-    FT_LCD_FILTER_DEFAULT = 1,
-    FT_LCD_FILTER_LIGHT   = 2,
-    FT_LCD_FILTER_LEGACY  = 16,
-
-    FT_LCD_FILTER_MAX   /* do not remove */
-
-  } FT_LcdFilter;
-
-
-  /**************************************************************************
-   *
-   * @func:
-   *   FT_Library_SetLcdFilter
-   *
-   * @description:
-   *   This function is used to apply color filtering to LCD decimated
-   *   bitmaps, like the ones used when calling @FT_Render_Glyph with
-   *   @FT_RENDER_MODE_LCD or @FT_RENDER_MODE_LCD_V.
-   *
-   * @input:
-   *   library ::
-   *     A handle to the target library instance.
-   *
-   *   filter ::
-   *     The filter type.
-   *
-   *     You can use @FT_LCD_FILTER_NONE here to disable this feature, or
-   *     @FT_LCD_FILTER_DEFAULT to use a default filter that should work
-   *     well on most LCD screens.
-   *
-   * @return:
-   *   FreeType error code.  0~means success.
-   *
-   * @note:
-   *   This feature is always disabled by default.  Clients must make an
-   *   explicit call to this function with a `filter' value other than
-   *   @FT_LCD_FILTER_NONE in order to enable it.
-   *
-   *   Due to *PATENTS* covering subpixel rendering, this function doesn't
-   *   do anything except returning `FT_Err_Unimplemented_Feature' if the
-   *   configuration macro FT_CONFIG_OPTION_SUBPIXEL_RENDERING is not
-   *   defined in your build of the library, which should correspond to all
-   *   default builds of FreeType.
-   *
-   *   The filter affects glyph bitmaps rendered through @FT_Render_Glyph,
-   *   @FT_Outline_Get_Bitmap, @FT_Load_Glyph, and @FT_Load_Char.
-   *
-   *   It does _not_ affect the output of @FT_Outline_Render and
-   *   @FT_Outline_Get_Bitmap.
-   *
-   *   If this feature is activated, the dimensions of LCD glyph bitmaps are
-   *   either larger or taller than the dimensions of the corresponding
-   *   outline with regards to the pixel grid.  For example, for
-   *   @FT_RENDER_MODE_LCD, the filter adds up to 3~pixels to the left, and
-   *   up to 3~pixels to the right.
-   *
-   *   The bitmap offset values are adjusted correctly, so clients shouldn't
-   *   need to modify their layout and glyph positioning code when enabling
-   *   the filter.
-   *
-   * @since:
-   *   2.3.0
-   */
-  FT_EXPORT( FT_Error )
-  FT_Library_SetLcdFilter( FT_Library    library,
-                           FT_LcdFilter  filter );
-
-
-  /**************************************************************************
-   *
-   * @func:
-   *   FT_Library_SetLcdFilterWeights
-   *
-   * @description:
-   *   Use this function to override the filter weights selected by
-   *   @FT_Library_SetLcdFilter.  By default, FreeType uses the quintuple
-   *   (0x00, 0x55, 0x56, 0x55, 0x00) for FT_LCD_FILTER_LIGHT, and (0x10,
-   *   0x40, 0x70, 0x40, 0x10) for FT_LCD_FILTER_DEFAULT and
-   *   FT_LCD_FILTER_LEGACY.
-   *
-   * @input:
-   *   library ::
-   *     A handle to the target library instance.
-   *
-   *   weights ::
-   *     A pointer to an array; the function copies the first five bytes and
-   *     uses them to specify the filter weights.
-   *
-   * @return:
-   *   FreeType error code.  0~means success.
-   *
-   * @note:
-   *   Due to *PATENTS* covering subpixel rendering, this function doesn't
-   *   do anything except returning `FT_Err_Unimplemented_Feature' if the
-   *   configuration macro FT_CONFIG_OPTION_SUBPIXEL_RENDERING is not
-   *   defined in your build of the library, which should correspond to all
-   *   default builds of FreeType.
-   *
-   *   This function must be called after @FT_Library_SetLcdFilter to have
-   *   any effect.
-   *
-   * @since:
-   *   2.4.0
-   */
-  FT_EXPORT( FT_Error )
-  FT_Library_SetLcdFilterWeights( FT_Library      library,
-                                  unsigned char  *weights );
-
-  /* */
-
-
-FT_END_HEADER
-
-#endif /* __FT_LCD_FILTER_H__ */
-
-
-/* END */