Add missing documentation

enkou-shaders/src/transform.rs

@@ -1,17 +1,25 @@
+//! # Transform
+//!
+//! Transforms are the "functions" in an iterated function system. They take in a point,
+//! and generate a new point. For fractal flames, transforms are always affine,
+//! but produce more interesting images once we add variations.
 use bytemuck::{Pod, Zeroable};
 use glam::{Affine2, Vec2};
 
+/// Affine transform for use in the [`chaos_game`](crate::chaos_game).
 #[derive(Copy, Clone, Pod, Zeroable)]
 #[repr(C)]
 pub struct Transform {
-    pub coefficients: Affine2,
+    coefficients: Affine2,
 }
 
 impl Transform {
+    /// Create a new transform from an affine transformation matrix
     pub fn new(coefficients: Affine2) -> Self {
         Transform { coefficients }
     }
 
+    /// Apply this transform to a point in IFS coordinates, producing a new point
     pub fn transform_point(&self, point: Vec2) -> Vec2 {
         self.coefficients.transform_point2(point)
     }