diff options
Diffstat (limited to 'Build/source/libs/freetype2/freetype-src/include/freetype/ftlcdfil.h')
-rw-r--r-- | Build/source/libs/freetype2/freetype-src/include/freetype/ftlcdfil.h | 19 |
1 files changed, 9 insertions, 10 deletions
diff --git a/Build/source/libs/freetype2/freetype-src/include/freetype/ftlcdfil.h b/Build/source/libs/freetype2/freetype-src/include/freetype/ftlcdfil.h index c6995f2ff7d..107a174da33 100644 --- a/Build/source/libs/freetype2/freetype-src/include/freetype/ftlcdfil.h +++ b/Build/source/libs/freetype2/freetype-src/include/freetype/ftlcdfil.h @@ -5,7 +5,7 @@ * FreeType API for color filtering of subpixel bitmap glyphs * (specification). * - * Copyright (C) 2006-2020 by + * Copyright (C) 2006-2021 by * David Turner, Robert Wilhelm, and Werner Lemberg. * * This file is part of the FreeType project, and may only be used, @@ -55,13 +55,12 @@ FT_BEGIN_HEADER * ClearType-style LCD rendering exploits the color-striped structure of * LCD pixels, increasing the available resolution in the direction of * the stripe (usually horizontal RGB) by a factor of~3. Using the - * subpixels coverages unfiltered can create severe color fringes + * subpixel coverages unfiltered can create severe color fringes * especially when rendering thin features. Indeed, to produce * black-on-white text, the nearby color subpixels must be dimmed - * equally. - * - * A good 5-tap FIR filter should be applied to subpixel coverages - * regardless of pixel boundaries and should have these properties: + * evenly. Therefore, an equalizing 5-tap FIR filter should be applied + * to subpixel coverages regardless of pixel boundaries and should have + * these properties: * * 1. It should be symmetrical, like {~a, b, c, b, a~}, to avoid * any shifts in appearance. @@ -84,7 +83,7 @@ FT_BEGIN_HEADER * Harmony LCD rendering is suitable to panels with any regular subpixel * structure, not just monitors with 3 color striped subpixels, as long * as the color subpixels have fixed positions relative to the pixel - * center. In this case, each color channel is then rendered separately + * center. In this case, each color channel can be rendered separately * after shifting the outline opposite to the subpixel shift so that the * coverage maps are aligned. This method is immune to color fringes * because the shifts do not change integral coverage. @@ -101,9 +100,9 @@ FT_BEGIN_HEADER * clockwise. Harmony with default LCD geometry is equivalent to * ClearType with light filter. * - * As a result of ClearType filtering or Harmony rendering, the - * dimensions of LCD bitmaps can be either wider or taller than the - * dimensions of the corresponding outline with regard to the pixel grid. + * As a result of ClearType filtering or Harmony shifts, the resulting + * dimensions of LCD bitmaps can be slightly wider or taller than the + * dimensions the original outline with regard to the pixel grid. * For example, for @FT_RENDER_MODE_LCD, the filter adds 2~subpixels to * the left, and 2~subpixels to the right. The bitmap offset values are * adjusted accordingly, so clients shouldn't need to modify their layout |