linesweeper 0.2.0

Boolean operations on paths (intersection, union, difference, xor) for font development

linesweeper

Python bindings for the linesweeper Rust crate, performing boolean operations on paths (intersection, union, difference, xor). Useful for font development and other vector graphics workflows.

Install

pip install linesweeper

Usage

Boolean operations on BezPaths

Use binary_op to perform boolean operations (union, intersection, difference, xor) on two sets of paths:

from kurbopy import BezPath
from linesweeper import binary_op

# Create two overlapping rectangles as BezPaths
path_a = BezPath.from_svg("M 0,0 L 100,0 L 100,100 L 0,100 Z")
path_b = BezPath.from_svg("M 50,50 L 150,50 L 150,150 L 50,150 Z")

# Union: combine both shapes
result = binary_op(path_a, path_b, "nonzero", "union")

# Intersection: keep only the overlapping region
result = binary_op(path_a, path_b, "nonzero", "intersection")

# Difference: subtract path_b from path_a
result = binary_op(path_a, path_b, "nonzero", "difference")

# Xor: keep non-overlapping regions
result = binary_op(path_a, path_b, "nonzero", "xor")

The fill_rule parameter can be "nonzero" or "evenodd".

Simplifying paths / removing overlaps

Use simplify to merge a list of overlapping BezPaths into a simplified result:

from kurbopy import BezPath
from linesweeper import simplify

paths = [
    BezPath.from_svg("M 0,0 L 100,0 L 100,100 L 0,100 Z"),
    BezPath.from_svg("M 50,50 L 150,50 L 150,150 L 50,150 Z"),
]
simplified = simplify(paths)

Removing overlaps from UFO contours

Use remove_overlaps to remove overlapping contours from a UFO glyph, using ufoLib2:

from ufoLib2 import Font
from linesweeper import remove_overlaps

font = Font.open("MyFont.ufo")

glyph = font["A"]
contours = list(glyph)
glyph.clearContours()
remove_overlaps(contours, glyph.getPen())

API Reference

binary_op(set_a, set_b, fill_rule, operation)

Performs a boolean operation on two BezPath objects.

• set_a / set_b: kurbopy.BezPath objects.
• fill_rule: "nonzero" or "evenodd".
• operation: "union", "intersection", "difference", or "xor".
• Returns: A list of BezPath objects.

simplify(bezpaths)

Simplifies a list of BezPath objects by performing a union operation.

• bezpaths: A list of kurbopy.BezPath objects.
• Returns: A list of simplified BezPath objects.

remove_overlaps(contours, pen)

Removes overlaps from a list of UFO Contour objects and draws the result to a pen.

• contours: A list of ufoLib2.objects.Contour objects.
• pen: A fontTools.pens.basePen.AbstractPen to draw the result to.

combine_paths(bezpaths)

Concatenates multiple BezPath objects into a single BezPath.

• bezpaths: A list of kurbopy.BezPath objects.
• Returns: A single BezPath.

Build from source

This package is built using maturin, which compiles the Rust code and creates a Python wheel:

pip install maturin
maturin develop --release

License

This project is licensed under the Apache 2.0 License. See the LICENSE.txt file for details.