removeOverlaps: Tools to remove overlapping contours in glyphs

Overview

The fontTools.ttLib.removeOverlaps module is a helper for fontTools.ttLib.

Simplify TrueType glyphs by merging overlapping contours/components.

Requires https://github.com/fonttools/skia-pathops

fontTools.ttLib.removeOverlaps.removeOverlaps(font: TTFont, glyphNames: Iterable[str] | None = None, removeHinting: bool = True, ignoreErrors: bool = False, *, removeUnusedSubroutines: bool = True) → None[source]

Simplify glyphs in TTFont by merging overlapping contours.

Overlapping components are first decomposed to simple contours, then merged.

Currently this only works for fonts with ‘glyf’ or ‘CFF ‘ tables. Raises NotImplementedError if ‘glyf’ or ‘CFF ‘ tables are absent.

Note that removing overlaps invalidates the hinting. By default we drop hinting from all glyphs whether or not overlaps are removed from a given one, as it would look weird if only some glyphs are left (un)hinted.

Parameters:

  • font – input TTFont object, modified in place.

  • glyphNames – optional iterable of glyph names (str) to remove overlaps from. By default, all glyphs in the font are processed.

  • removeHinting (bool) – set to False to keep hinting for unmodified glyphs.

  • ignoreErrors (bool) – set to True to ignore errors while removing overlaps, thus keeping the tricky glyphs unchanged (fonttools/fonttools#2363).

  • removeUnusedSubroutines (bool) – set to False to keep unused subroutines in CFF table after removing overlaps. Default is to remove them if any glyphs are modified.