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Update CHANGES file; other minor doc fixes.
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lemzwerg committed Jun 30, 2021
1 parent 69c3516 commit 90ecac4
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31 changes: 26 additions & 5 deletions docs/CHANGES
Expand Up @@ -79,13 +79,34 @@ CHANGES BETWEEN 2.10.4 and 2.11.0

- Improved Meson build support for the library.

- Meson support to build The FreeType demo programs.
- Meson support to build the FreeType demo programs.

- `ttdebug` didn't show changed point coordinates (bug introduced in
version 2.10.3).
- A new demo program `ftsdf` is available to display Signed Distance
Fields of glyphs.

- The graphical demos now work better in native color depth on win32
and x11.
- The `ftlint` demo program has been extended to do more testing of
its input. In particular, it can display horizontal and vertical
acutances for quality assessment, together with computing MD5
checksums of rendered glyphs.

[The acutance measures how sharply the pixel coverage changes at
glyph edges. For monochrome bitmaps, it is always 2.0 in either
X or Y direction. For anti-aliased bitmaps, it depends on the
hinting and the shape of a glyph and might approach or even reach
value 2.0 for glyphs like 'I', 'L', '+', '-', or '=', while it
might be lower for glyphs like 'O', 'S', or 'W'.]

- The `ttdebug` demo program didn't show changed point coordinates
(bug introduced in version 2.10.3).

- It is now possible to adjust the axis increment for variable fonts
in the `ftmulti` demo program.

- It is now possible to change the hinting engine in the `ftstring`
demo program.

- The graphical demo programs work better now in native color depth
on win32 and x11.


======================================================================
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1 change: 1 addition & 0 deletions docs/INSTALL.ANY
Expand Up @@ -73,6 +73,7 @@ I. Standard procedure
formats)

src/raster/raster.c -- monochrome rasterizer
src/sdf/sdf.c -- Signed Distance Field driver
src/smooth/smooth.c -- anti-aliasing rasterizer

-- auxiliary modules (optional)
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3 changes: 2 additions & 1 deletion include/freetype/freetype.h
Expand Up @@ -3445,7 +3445,8 @@ FT_BEGIN_HEADER
*
* which is known as the OVER operator.
*
* To correctly composite an antialiased pixel of a glyph onto a surface,
* To correctly composite an anti-aliased pixel of a glyph onto a
* surface,
*
* 1. take the foreground and background colors (e.g., in sRGB space)
* and apply gamma to get them in a linear space,
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10 changes: 5 additions & 5 deletions include/freetype/ftdriver.h
Expand Up @@ -84,15 +84,15 @@ FT_BEGIN_HEADER
* @properties section.
*
*
* **Hinting and antialiasing principles of the new engine**
* **Hinting and anti-aliasing principles of the new engine**
*
* The rasterizer is positioning horizontal features (e.g., ascender
* height & x-height, or crossbars) on the pixel grid and minimizing the
* amount of antialiasing applied to them, while placing vertical
* amount of anti-aliasing applied to them, while placing vertical
* features (vertical stems) on the pixel grid without hinting, thus
* representing the stem position and weight accurately. Sometimes the
* vertical stems may be only partially black. In this context,
* 'antialiasing' means that stems are not positioned exactly on pixel
* 'anti-aliasing' means that stems are not positioned exactly on pixel
* borders, causing a fuzzy appearance.
*
* There are two principles behind this approach.
Expand All @@ -108,15 +108,15 @@ FT_BEGIN_HEADER
* sizes are comparable to kerning values and thus would be noticeable
* (and distracting) while reading if hinting were applied.
*
* One of the reasons to not hint horizontally is antialiasing for LCD
* One of the reasons to not hint horizontally is anti-aliasing for LCD
* screens: The pixel geometry of modern displays supplies three vertical
* subpixels as the eye moves horizontally across each visible pixel. On
* devices where we can be certain this characteristic is present a
* rasterizer can take advantage of the subpixels to add increments of
* weight. In Western writing systems this turns out to be the more
* critical direction anyway; the weights and spacing of vertical stems
* (see above) are central to Armenian, Cyrillic, Greek, and Latin type
* designs. Even when the rasterizer uses greyscale antialiasing instead
* designs. Even when the rasterizer uses greyscale anti-aliasing instead
* of color (a necessary compromise when one doesn't know the screen
* characteristics), the unhinted vertical features preserve the design's
* weight and spacing much better than aliased type would.
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2 changes: 1 addition & 1 deletion src/sdf/ftsdfrend.c
Expand Up @@ -290,7 +290,7 @@
}

/* preset the bitmap using the glyph's outline; */
/* the sdf bitmap is similar to an antialiased bitmap */
/* the sdf bitmap is similar to an anti-aliased bitmap */
/* with a slightly bigger size and different pixel mode */
if ( ft_glyphslot_preset_bitmap( slot, FT_RENDER_MODE_NORMAL, origin ) )
{
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