flow-rbp: A library for packing rectangles into two-dimensional finite bins

Andreas — 2026-06-10 11:31:00

flow-rbp is a library for packing rectangles into two-dimensional finite bins using different heuristic methods for placement.

The two-dimensional rectangle bin packing is a classical problem in combinatorial optimization. In this problem, one is given a sequence of rectangles (R1, R2, ... Rn), Ri = (wi, hi) and the task is to find a packing of these items into a minimum number of bins of size (W, H). No two rectangles may intersect or be contained inside one another. This library uses an algorithm sometimes referred as The Maximal Rectangles ALgorithm. This algorithm stores a list of free rectangles that represents the free area of the bin.

flow-texpack is a program that uses flow-rbp to generate texture atlas.

Installing Rust

Install Rust from your package manager or by downloading from here: https://rust-lang.org/.

Getting the code

Install git from your package manager or by downloading from here: https://git-scm.com/install. The git repository can also be browsed online.

Clone the git repository:

git clone https://luflow.net/git/flow-rbp.git

Usage

Add this to your Cargo.toml:

[dependencies]
flow-rbp = { git = "https://luflow.net/git/flow-rbp.git", tag = "v0.1.0" }

Then:

use flow_rbp::FreeRectHeuristic;
use flow_rbp::RectsBinPack;

// create a new bin of size 32x32 which allows rotation:
let mut rbp = RectsBinPack::new(32, 32, true).unwrap();

// make sure occupancy is zero:
assert_eq!(rbp.get_occupancy(), 0.0);

// add a few rects that should fit:
assert_eq!(rbp.insert(16, 16, FreeRectHeuristic::BottomLeft).is_some(), true);
assert_eq!(rbp.insert(16, 16, FreeRectHeuristic::BottomLeft).is_some(), true);
assert_eq!(rbp.get_occupancy(), 0.5);
assert_eq!(rbp.insert(16, 16, FreeRectHeuristic::BottomLeft).is_some(), true);
assert_eq!(rbp.insert(16, 16, FreeRectHeuristic::BottomLeft).is_some(), true);
assert_eq!(rbp.get_occupancy(), 1.0);

// this rect will not fit and therefore returns None:
assert_eq!(rbp.insert(1, 1, FreeRectHeuristic::BottomLeft).is_none(), true);

License

flow-rbp is licensed under the zlib license. This license allows you to use flow-rbp freely in any software.