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| author | Anuj Verma <anujv@iitbhilai.ac.in> | 2021-07-13 10:00:22 +0200 |
|---|---|---|
| committer | Werner Lemberg <wl@gnu.org> | 2021-07-13 10:00:22 +0200 |
| commit | e592982a836c41050600d63ecf449ff8ab6a9a76 (patch) | |
| tree | e6e49720f10d815178472795293229ef83aefbee | |
| parent | c5516e0f7cd0c7075381b15d3194a640f4d35ee3 (diff) | |
| download | freetype2-e592982a836c41050600d63ecf449ff8ab6a9a76.tar.gz | |
[sdf] Improve documentation.
| -rw-r--r-- | include/freetype/freetype.h | 14 | ||||
| -rw-r--r-- | src/sdf/ftsdf.c | 3 |
2 files changed, 9 insertions, 8 deletions
diff --git a/include/freetype/freetype.h b/include/freetype/freetype.h index 29a0f7131..f393e3de5 100644 --- a/include/freetype/freetype.h +++ b/include/freetype/freetype.h @@ -3307,13 +3307,13 @@ FT_BEGIN_HEADER * pixels and use the @FT_PIXEL_MODE_LCD_V mode. * * FT_RENDER_MODE_SDF :: - * This mode corresponds to 8-bit signed distance fields (SDF) - * bitmaps. Each pixel in a SDF bitmap contains information about the - * nearest edge of the glyph outline. The distances are calculated - * from the center of the pixel and are positive if they are filled by - * the outline (i.e., inside the outline) and negative otherwise. - * Check the note below on how to convert the output values to usable - * data. + * This mode corresponds to 8-bit, single-channel signed distance field + * (SDF) bitmaps. Each pixel in the SDF grid is the value from the + * pixel's position to the nearest glyph's outline. The distances are + * calculated from the center of the pixel and are positive if they are + * filled by the outline (i.e., inside the outline) and negative + * otherwise. Check the note below on how to convert the output values + * to usable data. * * @note: * The selected render mode only affects vector glyphs of a font. diff --git a/src/sdf/ftsdf.c b/src/sdf/ftsdf.c index 65a8f329c..d3722b1dc 100644 --- a/src/sdf/ftsdf.c +++ b/src/sdf/ftsdf.c @@ -41,7 +41,8 @@ * file `ftbsdf.c` for more. * * * The basic idea of generating the SDF is taken from Viktor Chlumsky's - * research paper. + * research paper. The paper explains both single and multi-channel + * SDF, however, this implementation only generates single-channel SDF. * * Chlumsky, Viktor: Shape Decomposition for Multi-channel Distance * Fields. Master's thesis. Czech Technical University in Prague, |