From 9b499e6520e2603d09a5e8d5bd125d2ea2232c7b Mon Sep 17 00:00:00 2001
From: Albert Zhang <alchzh@gmail.com>
Date: Fri, 9 Oct 2020 12:48:02 -0400
Subject: [PATCH] Implement HSLUV based quasi-random hue color cycling for role
 colors

---
 app.js                |  2 ++
 lib/colorGenerator.js | 15 +++++++++++++++
 lib/teams.js          |  9 +--------
 package-lock.json     |  5 +++++
 package.json          |  1 +
 5 files changed, 24 insertions(+), 8 deletions(-)
 create mode 100644 lib/colorGenerator.js

diff --git a/app.js b/app.js
index 82b3ee8..ea1ce71 100644
--- a/app.js
+++ b/app.js
@@ -11,6 +11,7 @@ import { registerMany, register } from "./lib/discordjs-ext/register.js";
 
 import serverTemplate from "./serverTemplate.js";
 import createPartialMessage from "./lib/discordjs-ext/createPartialMessage.js";
+import colorGenerator from "./lib/colorGenerator.js";
 
 const client = new Client();
 
@@ -29,6 +30,7 @@ client.on("ready", async function onReady() {
   Promise.all(
     client.guilds.cache.map(guild => {
       console.log(`${guild.name} ${guild.owner.user.tag}`);
+      guild.colorGenerator = colorGenerator();
       return guild.roles.fetch();
     })
   ).then(() => {
diff --git a/lib/colorGenerator.js b/lib/colorGenerator.js
new file mode 100644
index 0000000..9f8fa89
--- /dev/null
+++ b/lib/colorGenerator.js
@@ -0,0 +1,15 @@
+import hsluv from "hsluv";
+
+// Golden Ratio
+// See rationale here: http://extremelearning.com.au/unreasonable-effectiveness-of-quasirandom-sequences/
+const phi = 1.6180339887498948482;
+const step = 1.0 / phi;
+
+export default function* colorGenerator(seed) {
+  let hue = seed || Math.random();
+
+  while (true) {
+    yield hsluv.hsluvToHex([hue * 360, 100, 65]);
+    hue = (hue + step) % 1;
+  }
+}
diff --git a/lib/teams.js b/lib/teams.js
index 76fd2ac..009124d 100644
--- a/lib/teams.js
+++ b/lib/teams.js
@@ -2,14 +2,7 @@ import { createRoom, addToRoom, deleteRoom } from "./rooms.js";
 
 // eslint-disable-next-line import/prefer-default-export
 export async function createTeam(guild, name) {
-  let color;
-  do {
-    color = [
-      Math.floor(Math.random() * 256),
-      Math.floor(Math.random() * 256),
-      Math.floor(Math.random() * 256),
-    ];
-  } while (color[0] + color[1] + color[2] < 128 || color[0] + color[1] + color[2] > 576);
+  const color = guild.colorGenerator.next().value;
 
   const teamRole = await guild.roles.create({
     data: {
diff --git a/package-lock.json b/package-lock.json
index fa63a0c..cdd4c8b 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -806,6 +806,11 @@
       "integrity": "sha512-f/wzC2QaWBs7t9IYqB4T3sR1xviIViXJRJTWBlx2Gf3g0Xi5vI7Yy4koXQ1c9OYDGHN9sBy1DQ2AB8fqZBWhUg==",
       "dev": true
     },
+    "hsluv": {
+      "version": "0.1.0",
+      "resolved": "https://registry.npmjs.org/hsluv/-/hsluv-0.1.0.tgz",
+      "integrity": "sha512-ERcanKLAszD2XN3Vh5r5Szkrv9q0oSTudmP0rkiKAGM/3NMc9FLmMZBB7TSqTaXJfSDBOreYTfjezCOYbRKqlw=="
+    },
     "ignore": {
       "version": "4.0.6",
       "resolved": "https://registry.npmjs.org/ignore/-/ignore-4.0.6.tgz",
diff --git a/package.json b/package.json
index 02687a7..ab68037 100644
--- a/package.json
+++ b/package.json
@@ -28,6 +28,7 @@
   "dependencies": {
     "discord-command-parser": "^1.4.3",
     "discord.js": "^12.3.1",
+    "hsluv": "^0.1.0",
     "parse-url": "^5.0.1"
   },
   "devDependencies": {