From de20da4e8652be889ed49f6d944f9652193f3f4e Mon Sep 17 00:00:00 2001
From: saji <saji@saji.dev>
Date: Thu, 1 Aug 2024 19:55:12 -0500
Subject: [PATCH] comments, make DitheredImage fields public

---
 src/dither.rs | 11 +++++------
 1 file changed, 5 insertions(+), 6 deletions(-)

diff --git a/src/dither.rs b/src/dither.rs
index 33a55ee..7ea316a 100644
--- a/src/dither.rs
+++ b/src/dither.rs
@@ -39,8 +39,8 @@ pub enum ProcessingError {
 /// Buffer to be sent to the ``EInk`` display.
 #[derive(Debug)]
 pub struct DitheredImage {
-    buf: ImageBuffer<Luma<u8>, Vec<u8>>,
-    palette: Vec<Srgb>,
+    pub buf: ImageBuffer<Luma<u8>, Vec<u8>>,
+    pub palette: Vec<Srgb>,
 }
 
 impl DitheredImage {
@@ -86,8 +86,7 @@ pub trait Ditherer {
     fn dither(&mut self, img: &RgbImage, output: &mut DitheredImage);
 }
 
-/// Find the closest approximate palette color to the given sRGB value.
-/// This uses euclidian distance in linear space.
+/// Find the closest approximate palette color
 fn nearest_neighbor(input_color: Lab, palette: &[Lab]) -> (u8, Lab) {
     let (nearest, _, color_diff) = palette
         .iter()
@@ -95,7 +94,7 @@ fn nearest_neighbor(input_color: Lab, palette: &[Lab]) -> (u8, Lab) {
         .map(|(idx, p_color)| {
             (
                 idx,
-                input_color.difference(*p_color),
+                input_color.difference(*p_color), // this is CIEDIE2000 based and highly accurate.
                 input_color - *p_color,
             )
         })
@@ -199,7 +198,7 @@ static STUKI_DITHER_POINTS: &[DiffusionPoint] = &[
 pub type DiffusionMatrix<'a> = &'a [DiffusionPoint];
 
 #[derive(Debug)]
-pub struct ErrorDiffusion<'a>(&'a [DiffusionPoint]);
+pub struct ErrorDiffusion<'a>(DiffusionMatrix<'a>);
 
 impl<'a> ErrorDiffusion<'a> {
     #[must_use]