From 4fcf68aef23a0615469ce8ef62d35a81913baddb Mon Sep 17 00:00:00 2001
From: Joscha <joscha@plugh.de>
Date: Fri, 14 Mar 2025 18:23:19 +0100
Subject: [PATCH] Add euclid-in-oklab distance option

---
 mark-bin/src/main.rs |  4 ++++
 mark/src/dither.rs   | 14 ++++++++++++--
 2 files changed, 16 insertions(+), 2 deletions(-)

diff --git a/mark-bin/src/main.rs b/mark-bin/src/main.rs
index 359c32b..1d11964 100644
--- a/mark-bin/src/main.rs
+++ b/mark-bin/src/main.rs
@@ -94,6 +94,8 @@ enum DitherDifference {
     HyAbClamp,
     Ciede2000,
     Ciede2000Clamp,
+    Oklab,
+    OklabClamp,
     Manhattan,
     ManhattanClamp,
 }
@@ -187,6 +189,8 @@ impl DitherCmd {
             HyAbClamp => self.run_cd::<C, DiffClamp<DiffHyAb>>(image),
             Ciede2000 => self.run_cd::<C, DiffCiede2000>(image),
             Ciede2000Clamp => self.run_cd::<C, DiffClamp<DiffCiede2000>>(image),
+            Oklab => self.run_cd::<C, DiffCiede2000>(image),
+            OklabClamp => self.run_cd::<C, DiffClamp<DiffCiede2000>>(image),
             Manhattan => self.run_cd::<C, DiffManhattan>(image),
             ManhattanClamp => self.run_cd::<C, DiffClamp<DiffManhattan>>(image),
         }
diff --git a/mark/src/dither.rs b/mark/src/dither.rs
index 8112d27..f81266a 100644
--- a/mark/src/dither.rs
+++ b/mark/src/dither.rs
@@ -9,8 +9,8 @@ use std::marker::PhantomData;
 
 use image::RgbaImage;
 use palette::{
-    Clamp, IntoColor, Lab, Srgb,
-    color_difference::{Ciede2000, HyAb},
+    Clamp, IntoColor, Lab, Oklab, Srgb,
+    color_difference::{Ciede2000, EuclideanDistance, HyAb},
 };
 use rand::{Rng, SeedableRng, rngs::SmallRng};
 
@@ -65,6 +65,16 @@ impl<C: IntoColor<Lab>> Difference<C> for DiffCiede2000 {
     }
 }
 
+pub struct DiffOklab;
+
+impl<C: IntoColor<Oklab>> Difference<C> for DiffOklab {
+    fn diff(a: C, b: C) -> f32 {
+        let a: Oklab = a.into_color();
+        let b: Oklab = b.into_color();
+        a.distance(b)
+    }
+}
+
 pub struct DiffManhattan;
 
 impl<C: AsRef<[f32; 3]>> Difference<C> for DiffManhattan {