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authorAkira Kakuto <kakuto@fuk.kindai.ac.jp>2021-09-01 05:58:30 +0000
committerAkira Kakuto <kakuto@fuk.kindai.ac.jp>2021-09-01 05:58:30 +0000
commit5f2b26791fe1a95ce022cb5e3dc21e389410d8cb (patch)
tree3f2032da43885b6530190de5e2c09b85b571c87b /Build/source/libs/freetype2/freetype-src/include/freetype/ftlcdfil.h
parent5b0099f6c7a0e15e36b0f556f41332724fbec7f6 (diff)
freetype 2.11.0
git-svn-id: svn://tug.org/texlive/trunk@60386 c570f23f-e606-0410-a88d-b1316a301751
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.h19
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