Add missing documentation

enkou-shaders/src/chaos_game.rs

@@ -1,3 +1,17 @@
+//! # Chaos Game
+//!
+//! Fractal flames are a class of
+//! [iterated function systems](https://en.wikipedia.org/wiki/Iterated_function_system)
+//! that generate images following a simple algorithm:
+//!
+//! - Pick a starting point `(x, y)`
+//! - Iterate:
+//!     - Pick a [`Transform`] from the set of available transforms
+//!     - Apply the current point to the chosen transform, generating a new point `(x, y)`
+//!     - Plot the new point `(x, y)`
+//!
+//! This algorithm is also known as the ["chaos game"](https://en.wikipedia.org/wiki/Chaos_game),
+//! and it forms the basic system for producing images.
 use crate::transform::Transform;
 use glam::{Vec2, vec2};
 use rand::distr::{Distribution, StandardUniform};
@@ -42,6 +56,10 @@ pub fn step_chaos_game<R: Rng>(
     )
 }
 
+/// Iterator for chaos game state. Holds the current point and references to all other data
+/// necessary to generate fractal flame images.
+///
+/// New points in the chaos game are produced by iterating on the chaos game.
 pub struct ChaosGame<'a, R: Rng> {
     current_point: Vec2,
     rng: &'a mut R,
@@ -50,6 +68,7 @@ pub struct ChaosGame<'a, R: Rng> {
 }
 
 impl<'a, R: Rng> ChaosGame<'a, R> {
+    /// Create a new chaos game iterator
     pub fn new(rng: &'a mut R, transforms: &'a [Transform], weights: &'a [f32]) -> Self {
         let current_point = vec2(rng.sample(BiUnit), rng.sample(BiUnit));
         ChaosGame {