Werner Lemberg pushed to branch master at FreeType / FreeType
Commits:
-
e592982a
by Anuj Verma at 2021-07-13T10:00:22+02:00
2 changed files:
Changes:
| ... | ... | @@ -3307,13 +3307,13 @@ FT_BEGIN_HEADER |
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* pixels and use the @FT_PIXEL_MODE_LCD_V mode.
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*
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* FT_RENDER_MODE_SDF ::
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- * This mode corresponds to 8-bit signed distance fields (SDF)
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- * bitmaps. Each pixel in a SDF bitmap contains information about the
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- * nearest edge of the glyph outline. The distances are calculated
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- * from the center of the pixel and are positive if they are filled by
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- * the outline (i.e., inside the outline) and negative otherwise.
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- * Check the note below on how to convert the output values to usable
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- * data.
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+ * This mode corresponds to 8-bit, single-channel signed distance field
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+ * (SDF) bitmaps. Each pixel in the SDF grid is the value from the
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+ * pixel's position to the nearest glyph's outline. The distances are
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+ * calculated from the center of the pixel and are positive if they are
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+ * filled by the outline (i.e., inside the outline) and negative
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+ * otherwise. Check the note below on how to convert the output values
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+ * to usable data.
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*
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* @note:
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* The selected render mode only affects vector glyphs of a font.
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* file `ftbsdf.c` for more.
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*
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* * The basic idea of generating the SDF is taken from Viktor Chlumsky's
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- * research paper.
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+ * research paper. The paper explains both single and multi-channel
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+ * SDF, however, this implementation only generates single-channel SDF.
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*
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* Chlumsky, Viktor: Shape Decomposition for Multi-channel Distance
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* Fields. Master's thesis. Czech Technical University in Prague,
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