Polybool

Boolean operations on polygons: union, intersection, difference, xor.

Why polybool?

Flutter had no package for polygon Boolean operations until now.
polybool is the first and only library in Dart that lets you:

• Combine polygons (union)
• Find overlaps (intersection)
• Cut one shape from another (difference)
• Exclusive regions (XOR)

If you’ve ever needed polygon clipping in Flutter — for maps, games, or graphics apps —
this package saves you from writing complex geometry algorithms yourself.

Resources

Note: taken from original libaray polybooljs

• Demo + Animation
• Companion Tutorial

This library is based on:

• polybooljs by velipso@, which is based on
• polybool C++ by akavel@, which is based on
• an implementation by Mahir Iqbal, which is based on
• F. Martinez' (2008) algorithm (Paper)Code

Features

1. Clips polygons for all boolean operations
2. Removes unnecessary vertices
3. Handles segments that are coincident (overlap perfectly, share vertices, one inside the other, etc)
4. Uses formulas that take floating point irregularities into account
5. Provides an API for constructing efficient sequences of operations

How to use it

    final poly1 = Polygon(regions: [
      [
        Coordinate(37.27935791015625, 29.32472016151103),
        Coordinate(37.122802734375, 29.257648503615542),
        Coordinate(37.22442626953125, 29.135369220927156),
        Coordinate(37.36175537109374, 29.221699149280646),
        Coordinate(37.27935791015625, 29.32472016151103),
      ],
    ]);

    final poly2 = Polygon(regions: [
      [
        Coordinate(37.104949951171875, 29.159357041355424),
        Coordinate(37.1722412109375, 29.046565622728846),
        Coordinate(37.31781005859375, 29.105376571809618),
        Coordinate(37.20794677734375, 29.216904948184734),
        Coordinate(37.104949951171875, 29.159357041355424),
      ]
    ]);

    final union = poly1.union(poly2);
    final intersection = poly1.intersect(poly2);
    final difference = poly1.difference(poly2);
    final inverseDifference = poly1.differenceRev(poly2);
    final xor = poly1.xor(poly2);