From 9725a1402afa9ab8f45dd329357ca5c719c8e8fa Mon Sep 17 00:00:00 2001
From: Brion Vibber <brion@pobox.com>
Date: Sat, 5 Nov 2022 20:08:47 -0700
Subject: [PATCH] wip

---
 dither4.js | 43 +++++++++++++++++++++++++++++++++++++------
 1 file changed, 37 insertions(+), 6 deletions(-)

diff --git a/dither4.js b/dither4.js
index 2641aa1..f74101d 100644
--- a/dither4.js
+++ b/dither4.js
@@ -415,15 +415,20 @@ function decimate(input, palette, n) {
             */
 
             /*
+            error.red[x] += nextError.r;
+            error.green[x] += nextError.g;
+            error.blue[x] += nextError.b;
+            */
+
             error.right.r = nextError.r / 2;
             error.right.g = nextError.g / 2;
             error.right.b = nextError.b / 2;
 
-            error.red[x + 1] += nextError.r / 2;
-            error.green[x + 1] += nextError.g / 2;
-            error.blue[x + 1] += nextError.b / 2;
-            */
+            error.red[x] += nextError.r / 2;
+            error.green[x] += nextError.g / 2;
+            error.blue[x] += nextError.b / 2;
 
+            /*
             error.right.r = nextError.r / 2;
             error.right.g = nextError.g / 2;
             error.right.b = nextError.b / 2;
@@ -439,8 +444,28 @@ function decimate(input, palette, n) {
             error.red[x + 1] += nextError.r / 8;
             error.green[x + 1] += nextError.g / 8;
             error.blue[x + 1] += nextError.b / 8;
+            */
 
-            fitness[x] = 1 - (nextError.magnitude() / 442);
+            /*
+            error.right.r = nextError.r / 4;
+            error.right.g = nextError.g / 4;
+            error.right.b = nextError.b / 4;
+
+            error.red[x - 1] += nextError.r / 4;
+            error.green[x - 1] += nextError.g / 4;
+            error.blue[x - 1] += nextError.b / 4;
+
+            error.red[x] += nextError.r / 4;
+            error.green[x] += nextError.g / 4;
+            error.blue[x] += nextError.b / 4;
+
+            error.red[x + 1] += nextError.r / 4;
+            error.green[x + 1] += nextError.g / 4;
+            error.blue[x + 1] += nextError.b / 4;
+            */
+
+            // 442 is the 3d distance across the rgb cube
+            fitness[x] = 442 - (nextError.magnitude());
         }
         return {
             output,
@@ -466,14 +491,20 @@ function decimate(input, palette, n) {
             if (decimated[i].r == 255 && decimated[i].g == 255 && decimated[i].b == 255) {
                 continue; // keep white always
             }
+
             let coolFactor = popularity[i];
+
             /*
+
+            let coolFactor = 0;
             for (let x = 0; x < line.length; x++) {
                 if (output[x] == i) {
-                    coolFactor *= fitness[x];
+                    coolFactor += fitness[x];
                 }
             }
+            coolFactor /= Math.sqrt(popularity[i]);
             */
+
             if (coolFactor < least) {
                 pick = i;
                 least = coolFactor;