From 536dce6a985718a55237f475b2d31be6f0b93449 Mon Sep 17 00:00:00 2001
From: Jared Miller <jared@smell.flowers>
Date: Thu, 12 Feb 2026 21:10:39 -0500
Subject: [PATCH] Use set for O(1) palette color deduplication

---
 playscii/palette.py | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/playscii/palette.py b/playscii/palette.py
index 812f2ef..d3a77af 100644
--- a/playscii/palette.py
+++ b/playscii/palette.py
@@ -72,6 +72,7 @@ class Palette:
         # scan image L->R T->B for unique colors, store em as tuples
         # color 0 is always fully transparent
         self.colors = [(0, 0, 0, 0)]
+        seen = {(0, 0, 0, 0)}
         # determine lightest and darkest colors in palette for defaults
         lightest = 0
         darkest = 255 * 3 + 1
@@ -82,7 +83,8 @@ class Palette:
                 if len(self.colors) >= MAX_COLORS:
                     break
                 color = src_img.getpixel((x, y))
-                if color not in self.colors:
+                if color not in seen:
+                    seen.add(color)
                     self.colors.append(color)
                     # is this lightest/darkest unique color so far? save index
                     luminosity = color[0] * 0.21 + color[1] * 0.72 + color[2] * 0.07