ProcessCmap sanitize the given 'cmap' subtable, and select the best encoding when several subtables are given.

The [GlyphBitmap.Data] slice stores a black or white (0/1) bit image, whose length L satisfies L * 8 >= [GlyphBitmap.Width] * [GlyphBitmap.Height].

EmptyGlyph represents an invisible glyph, which should not be drawn, but whose advance and offsets should still be accounted for when rendering.

The [GlyphBitmap.Data] slice stores a JPG encoded image.

The [GlyphBitmap.Data] slice stores a PNG encoded image.

Distance above the baseline of the top of the strikethrough.

Suggested thickness to draw for the strikethrough.

The [GlyphBitmap.Data] slice stores a TIFF encoded image.

Distance above the baseline of the top of the underline.

Suggested thickness to draw for the underline.

VariantFound is returned when the font has a variant for the glyph and selector.

VariantNotFound is returned when the font does not have a glyph for the given rune and selector.

VariantUseDefault is returned when the regular glyph should be used (ignoring the selector).

BitmapSize expose the size of bitmap glyphs.

FontExtents exposes font-wide extent values, measured in font units.

FontID represents an identifier of a font (possibly in a collection), and an optional variable instance.

GlyphExtents exposes extent values, measured in font units.

GlyphOutline exposes the path to draw for vector glyph.

GlyphSVG is an SVG description for the glyph, as found in Opentype SVG table.

Cmap stores a compact representation of a cmap, offering both on-demand rune lookup and full rune range.

CmapIter is an interator over a Cmap.

CmapRuneRanger is implemented by cmaps whose coverage is defined in terms of rune ranges.

GlyphData describe how to graw a glyph.

BitmapFormat identifies the format on the glyph raw data.

GID is used to identify glyphs in a font.

LineMetric identifies one metric about the font.