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| author | Alexei Podtelezhnikov <apodtele@gmail.com> | 2017-03-09 00:08:38 -0500 |
|---|---|---|
| committer | Alexei Podtelezhnikov <apodtele@gmail.com> | 2017-08-08 22:29:51 -0400 |
| commit | 410f3799b6a193e20b34c574e6f0f2be2428b1eb (patch) | |
| tree | 4ffe187bc74d51aab76ce343aa5d221a90a32f11 /include/freetype/config/ftoption.h | |
| parent | 5710ef989da2be3db21d875ac48eb980564c052b (diff) | |
| download | freetype2-410f3799b6a193e20b34c574e6f0f2be2428b1eb.tar.gz | |
[smooth] Harmony LCD rendering.
This is a new technology for LCD-optimized rendering. It capitalizes
on the fact that each color channel grid is shifted by a third of a
pixel. Therefore it is logical to render 3 separate monochrome
bitmaps shifting the outline by 1/3 pixel, and then combine them.
Importantly, the resulting output does not require additional LCD
filtering.
* src/smooth/ftsmooth.c (ft_smooth_render_generic)
[!FT_CONFIG_OPTION_SUBPIXEL_RENDERING]: Implement new LCD-optimized
rendering.
* include/freetype/ftlcdfil.h, include/freetype/freetype.h,
include/freetype/config/ftoption.h, devel/ftoption.h: Updated
documentation.
Diffstat (limited to 'include/freetype/config/ftoption.h')
| -rw-r--r-- | include/freetype/config/ftoption.h | 19 |
1 files changed, 8 insertions, 11 deletions
diff --git a/include/freetype/config/ftoption.h b/include/freetype/config/ftoption.h index 935e20d8d..2fbe80b9b 100644 --- a/include/freetype/config/ftoption.h +++ b/include/freetype/config/ftoption.h @@ -107,20 +107,17 @@ FT_BEGIN_HEADER /*************************************************************************/ /* */ - /* Uncomment the line below if you want to activate sub-pixel rendering */ - /* (a.k.a. LCD rendering, or ClearType) in this build of the library. */ + /* Uncomment the line below if you want to activate LCD rendering */ + /* technology similar to ClearType in this build of the library. This */ + /* technology triples the resolution in the direction color subpixels. */ + /* To mitigate color fringes inherent to this technology, you also need */ + /* to explicitly set up LCD filtering. */ /* */ /* Note that this feature is covered by several Microsoft patents */ /* and should not be activated in any default build of the library. */ - /* */ - /* This macro has no impact on the FreeType API, only on its */ - /* _implementation_. For example, using FT_RENDER_MODE_LCD when calling */ - /* FT_Render_Glyph still generates a bitmap that is 3 times wider than */ - /* the original size in case this macro isn't defined; however, each */ - /* triplet of subpixels has R=G=B. */ - /* */ - /* This is done to allow FreeType clients to run unmodified, forcing */ - /* them to display normal gray-level anti-aliased glyphs. */ + /* When this macro is not defined, FreeType offers alternative LCD */ + /* rendering technology that produces excellent output without LCD */ + /* filtering. */ /* */ /* #define FT_CONFIG_OPTION_SUBPIXEL_RENDERING */ |