Al-Qurtas-Islamic-bank-The-.../include/freetype/ftlcdfil.h

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/***************************************************************************/
/* */
/* ftlcdfil.h */
/* */
/* FreeType API for color filtering of subpixel bitmap glyphs */
/* (specification). */
/* */
/* Copyright 2006 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. */
/* */
/***************************************************************************/
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#ifndef __FT_LCD_FILTER_H__
#define __FT_LCD_FILTER_H__
#include <ft2build.h>
#include FT_FREETYPE_H
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FT_BEGIN_HEADER
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/****************************************************************************
*
* @func:
* 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 than the default one, depending on the monitor, personal
* vision, and taste.
*
* 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.
*/
typedef enum
{
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;
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/**************************************************************************
*
* @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:
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* library ::
* A handle to the target library instance.
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*
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* filter ::
* The filter type.
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*
* 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
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* explicit call to this function with a `filter' value other than
* @FT_LCD_FILTER_NONE in order to enable it.
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*
* Due to *PATENTS* covering subpixel rendering, this function doesn't
* do anything except returning `FT_Err_Unimplemented_Feature' if the
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* configuration macro FT_CONFIG_OPTION_SUBPIXEL_RENDERING is not
* defined in your build of the library, which should correspond to all
* default builds of the library.
*
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* The filter affects glyph bitmaps rendered through @FT_Render_Glyph,
* @FT_Outline_Get_Bitmap, @FT_Load_Glyph, and @FT_Load_Char.
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*
* 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.
*
*/
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FT_EXPORT( FT_Error )
FT_Library_SetLcdFilter( FT_Library library,
FT_LcdFilter filter );
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/* */
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FT_END_HEADER
#endif /* __FT_LCD_FILTER_H__ */
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/* END */