From 6028bb419e702950454757637e389ccb9b8c9ac5 Mon Sep 17 00:00:00 2001
From: Vftdan <vftdan@gmail.com>
Date: Thu, 3 Oct 2024 11:26:45 +0200
Subject: [PATCH] Avoid duplicate palette entries

Don't make an item an empty cluster warp candidate, if it is already
warp candidate for another cluster
---
 img2cpi.c | 18 +++++++++++++++---
 1 file changed, 15 insertions(+), 3 deletions(-)

diff --git a/img2cpi.c b/img2cpi.c
index 960bb54..9b3fb11 100644
--- a/img2cpi.c
+++ b/img2cpi.c
@@ -711,9 +711,21 @@ bool k_means_iteration(struct k_means_state *state) {
         closest_distance = dist;
         closest_cluster = cluster;
       }
-      if (dist <= state->centroid_intermediate[cluster].closest_present_distance) {
-        state->centroid_intermediate[cluster].closest_present_item = item;
-        state->centroid_intermediate[cluster].closest_present_distance = dist;
+      if (dist < state->centroid_intermediate[cluster].closest_present_distance) {
+        bool can_update = true;
+        for (int other_cluster = 0; other_cluster < state->clusters->count; other_cluster++) {
+          if (other_cluster == cluster) {
+            continue;
+          }
+          if (state->centroid_intermediate[other_cluster].closest_present_item.v == item.v) {
+            can_update = false;
+            break;
+          }
+        }
+        if (can_update) {
+          state->centroid_intermediate[cluster].closest_present_item = item;
+          state->centroid_intermediate[cluster].closest_present_distance = dist;
+        }
       }
     }
     if (!changed) {