earcut.zig

Zig port of mapbox/earcut — a fast polygon triangulation algorithm. Takes a flat vertex array and returns triangle indices. Supports concave polygons and holes.

Install

zig fetch --save https://github.com/tenyoru/earcut.zig/archive/refs/heads/main.tar.gz

build.zig:

const earcut = b.dependency("earcut", .{
    .target = target,
    .optimize = optimize,
});
exe.root_module.addImport("earcut", earcut.module("earcut"));

Usage

const earcut = @import("earcut");

const indices = try earcut.earcut(allocator, &vertices, null, 2);
defer allocator.free(indices);

// with holes:
const indices = try earcut.earcut(allocator, &vertices, &hole_indices, 2);
defer allocator.free(indices);

WASM

Use std.heap.wasm_allocator — no other changes needed:

const indices = try earcut.earcut(std.heap.wasm_allocator, &vertices, null, 2);

Credits

Algorithm by Mapbox (ISC License).