Crate dcc_lsystem

dcc-lsystem

A crate for working with Lindenmayer systems.

Background

An L-System consists of an alphabet of symbols that can be used to make strings, a collection of production rules that expand each symbol into a larger string of symbols, an initial axiom string from which to begin construction, and a mechanism for transforming the generated strings into geometric structures.

Algae example

Lindenmayer's original L-System for modelling the growth of Algae had variables A and B, axiom A, and production rules A -> AB, B -> A. Iterating this system produces the following output:

0. A
1. AB
2. ABA
3. ABAAB

Basic usage

Put the following in your Cargo.toml:

dcc-lsystem = "0.4.0"

An L-system is represented in this crate by an instance of LSystem. The suggested method for constructing an LSystem is to use a LSystemBuilder, as shown in this implementation of Lindenmayer's Algae system:

use dcc_lsystem::{LSystemBuilder, variable};

let mut builder = LSystemBuilder::new();

// Set up our two tokens
let a = variable!(builder, "A"); // expands to builder.token("A", TokenType::Variable)
let b = variable!(builder, "B"); // similar

// Set up our axiom
builder.axiom(vec![a]);

// Set the transformation rules
builder.transformation_rule(a, vec![a,b]); // A -> AB
builder.transformation_rule(b, vec![a]);   // B -> A

// Build our LSystem, which should have initial state A
let mut system = builder.finish();
assert_eq!(system.render(), "A");

// system.step() applies our production rules a single time
system.step();
assert_eq!(system.render(), "AB");

system.step();
assert_eq!(system.render(), "ABA");

// system.step_by() applies our production rule a number of times
system.step_by(5);
assert_eq!(system.render(), "ABAABABAABAABABAABABAABAABABAABAAB");

License

Licensed under either of

• Apache License, Version 2.0 (LICENSE-APACHE or http://www.apache.org/licenses/LICENSE-2.0)
• MIT license (LICENSE-MIT or http://opensource.org/licenses/MIT)

at your option.

Contribution

Unless you explicitly state otherwise, any contribution intentionally submitted for inclusion in the work by you, as defined in the Apache-2.0 license, shall be dual licensed as above, without any additional terms or conditions.

Re-exports

pub use arena::Arena;

pub use arena::ArenaId;

pub use builder::LSystemBuilder;

pub use system::LSystem;

pub use token::TokenType;

Modules

arena
builder
image
lattice
renderer
system
token
turtle

Macros

constant
variable