CoS hover cursor fix

CHANGELOG.md

@@ -4,6 +4,12 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
+## [v4.6.0] - unreleased
+### Changed
+- We are now using djb2xor instead of sha256 to hash puzzle answers
+- Lots of work on the built-in theme
+- [moth.mjs](theme/moth.mjs) is now the standard MOTH library for ECMAScript
+
 ## [v4.4.9] - 2022-05-12
 ### Changed
 - Added a performance optimization for events with a large number of teams

theme/background.mjs

@@ -87,7 +87,7 @@ class QixLine {
  * like the video game "qix"
  */
 class QixBackground {
-    constructor(ctx) {
+    constructor(ctx, frameInterval = SECOND/6) {
         this.ctx = ctx
         this.min = new Point(0, 0)
         this.max = new Point(this.ctx.canvas.width, this.ctx.canvas.height)
@@ -105,17 +105,25 @@ class QixBackground {
         }
         this.velocity = new QixLine(
             0.001,
-            new Point(1 + randint(this.box.x / 200), 1 + randint(this.box.y / 200)),
-            new Point(1 + randint(this.box.x / 200), 1 + randint(this.box.y / 200)),
+            new Point(1 + randint(this.box.x / 100), 1 + randint(this.box.y / 100)),
+            new Point(1 + randint(this.box.x / 100), 1 + randint(this.box.y / 100)),
         )
 
-        setInterval(() => this.animate(), SECOND/6)
+        this.frameInterval = frameInterval
+        this.nextFrame = 0
     }
 
     /**
-     * Animate one frame
+     * Maybe draw a frame
      */
-    animate() {
+    Animate() {
+        let now = performance.now()
+        if (now < this.nextFrame) {
+            // Not today, satan
+            return
+        }
+        this.nextFrame = now + this.frameInterval
+
         this.lines.shift()
         let lastLine = this.lines[this.lines.length - 1]
         let nextLine = new QixLine(
@@ -129,7 +137,7 @@ class QixBackground {
         this.ctx.clearRect(0, 0, this.ctx.canvas.width, this.ctx.canvas.height)
         for (let line of this.lines) {
             this.ctx.save()
-            this.ctx.strokeStyle = `hwb(${line.hue}turn 0% 50%)`
+            this.ctx.strokeStyle = `hwb(${line.hue}turn 0% 0%)`
             this.ctx.beginPath()
             this.ctx.moveTo(line.a.x, line.a.y)
             this.ctx.lineTo(line.b.x, line.b.y)
@@ -148,7 +156,9 @@ function init() {
 
     let ctx = canvas.getContext("2d")
 
-    new QixBackground(ctx)
+    let qix = new QixBackground(ctx)
+    setInterval(() => qix.Animate(), SECOND/6)
+
 }
 
 if (document.readyState === "loading") {

theme/basic.css

@@ -22,17 +22,6 @@ h1 {
 a:any-link {
 	color: #b9cbd8;
 }
-canvas.wallpaper {
-  position: fixed;
-  display: block;
-  z-index: -1000;
-  top: 0;
-  left: 0;
-  height: 100vh;
-  width: 100vw;
-  opacity: 0.3;
-  image-rendering: pixelated;
-}
 .notification {
 	background: #ac8f3944;
 }
@@ -55,6 +44,21 @@ canvas.wallpaper {
 
 body {
   font-family: sans-serif;
+  background-image: url("bg.png");
+  background-size: contain;
+  background-blend-mode: soft-light;
+  background-attachment: fixed;
+}
+canvas.wallpaper {
+  position: fixed;
+  display: block;
+  z-index: -1000;
+  top: 0;
+  left: 0;
+  height: 100vh;
+  width: 100vw;
+  opacity: 0.2;
+  image-rendering: pixelated;
 }
 main {
   max-width: 40em;
@@ -98,6 +102,9 @@ img {
 input:invalid {
   border-color: red;
 }
+.answer_ok {
+  cursor: help;
+}
 #messages {
   min-height: 3em;
 }

theme/hash.mjs

@@ -0,0 +1,20 @@
+// Dan Bernstein hash v1
+// Used until MOTH v3.5
+function djb2(buf) {
+    let h = 5381
+    for (let c of (new TextEncoder()).encode(buf)) { // Encode as UTF-8 and read in each byte
+      // JavaScript converts everything to a signed 32-bit integer when you do bitwise operations.
+      // So we have to do "unsigned right shift" by zero to get it back to unsigned.
+      h = (((h * 33) + c) & 0xffffffff) >>> 0
+    }
+    return h
+  }
+  
+  // Used until MOTH v4.5
+  async function sha256(message) {
+    const msgUint8 = new TextEncoder().encode(message);                           // encode as (utf-8) Uint8Array
+    const hashBuffer = await crypto.subtle.digest('SHA-256', msgUint8);           // hash the message
+    const hashArray = Array.from(new Uint8Array(hashBuffer));                     // convert buffer to byte array
+    const hashHex = hashArray.map(b => b.toString(16).padStart(2, '0')).join(''); // convert bytes to hex string
+    return hashHex;
+  }

theme/moth.mjs

@@ -1,3 +1,65 @@
+/**
+ * Hash/digest functions
+ */
+class Hash {
+    /**
+     * Dan Bernstein hash
+     * 
+     * Used until MOTH v3.5
+     * 
+     * @param {String} buf Input
+     * @returns {Number}
+     */
+    static djb2(buf) {
+        let h = 5381
+        for (let c of (new TextEncoder()).encode(buf)) { // Encode as UTF-8 and read in each byte
+            // JavaScript converts everything to a signed 32-bit integer when you do bitwise operations.
+            // So we have to do "unsigned right shift" by zero to get it back to unsigned.
+            h = (((h * 33) + c) & 0xffffffff) >>> 0
+        }
+        return h
+    }
+
+    /**
+     * Dan Bernstein hash with xor improvement
+     * 
+     * @param {String} buf Input
+     * @returns {Number}
+     */
+    static djb2xor(buf) {
+        let h = 5381
+        for (let c of (new TextEncoder()).encode(buf)) {
+            h = h * 33 ^ c
+        }
+        return h
+    }
+  
+    /**
+     * SHA 256
+     * 
+     * Used until MOTH v4.5
+     * 
+     * @param {String} buf Input
+     * @returns {String} hex-encoded digest
+     */
+   static async sha256(buf) {
+    const msgUint8 = new TextEncoder().encode(buf)
+    const hashBuffer = await crypto.subtle.digest('SHA-256', msgUint8)
+    const hashArray = Array.from(new Uint8Array(hashBuffer))
+    return this.hexlify(hashArray);
+  }
+
+  /**
+   * Hex-encode a byte array
+   * 
+   * @param {Number[]} buf Byte array
+   * @returns {String}
+   */
+  static async hexlify(buf) {
+    return buf.map(b => b.toString(16).padStart(2, "0")).join("")   
+  }
+}
+
 /**
  * A point award.
  */
@@ -103,6 +165,23 @@ class Puzzle {
     Get(filename) {
         return this.server.GetContent(this.Category, this.Points, filename)
     }
+
+    async IsPossiblyCorrect(str) {
+        let userAnswerHashes = [
+            Hash.djb2(str),
+            Hash.djb2xor(str),
+            await Hash.sha256(str),
+        ]
+
+        for (let pah of this.AnswerHashes) {
+            for (let uah of userAnswerHashes) {
+                if (pah == uah) {
+                    return true
+                }
+            }
+        }
+        return false
+    }
 }
 
 /**
@@ -343,5 +422,6 @@ class Server {
 }
 
 export {
-    Server
+    Hash,
+    Server,
 }

theme/puzzle.html

@@ -6,8 +6,8 @@
     <meta charset="utf-8">
     <link rel="icon" href="luna-moth.svg">
     <link rel="stylesheet" href="basic.css">
-    <script src="puzzle.mjs" type="module"></script>
-    <script src="background.mjs" type="module"></script>
+    <script src="background.mjs" type="module" async></script>
+    <script src="puzzle.mjs" type="module" async></script>
   </head>
   <body>
     <main>
@@ -23,7 +23,7 @@
       </section>
       <form class="answer">
         Team ID: <input type="text" name="id"> <br>
-        Answer: <input type="text" name="answer"> <span id="answer_ok"></span><br>
+        Answer: <input type="text" name="answer" id="answer"> <span class="answer_ok"></span><br>
         <input type="submit" value="Submit">
       </form>
     </main>

theme/puzzle.js

@@ -19,7 +19,7 @@ function devel_addin(e) {
   if (log.length > 0) {
     e.appendChild(document.createElement("h3")).textContent = "Log"
     let le = e.appendChild(document.createElement("ul"))
-    for (entry of log) {
+    for (let entry of log) {
       le.appendChild(document.createElement("li")).textContent = entry
     }
   }

theme/puzzle.mjs

@@ -1,13 +1,45 @@
 import * as moth from "./moth.mjs"
 
-/** Stores the current puzzle, globally */
-let puzzle = null
-
-function submit(event) {
+/**
+ * Handle a submit event on a form.
+ * 
+ * This event will be called when the user submits the form,
+ * either by clicking a "submit" button,
+ * or by some other means provided by the browser,
+ * like hitting the Enter key.
+ * 
+ * @param {Event} event 
+ */
+function formSubmitHandler(event) {
     event.preventDefault()
     console.log(event)
 }
 
+/**
+ * Handle an input event on the answer field.
+ * 
+ * @param {Event} event 
+ */
+async function answerInputHandler(event) {
+    let answer = event.target.value
+    let correct = await window.app.puzzle.IsPossiblyCorrect(answer)
+    for (let ok of event.target.parentElement.querySelectorAll(".answer_ok")) {
+        if (correct) {
+            ok.textContent = "⭕"
+            ok.title = "Possibly correct"
+        } else {
+            ok.textContent = "❌"
+            ok.title = "Definitely not correct"
+        }
+    }
+}
+
+/**
+ * Return the puzzle content element, possibly with everything cleared out of it.
+ * 
+ * @param {Boolean} clear Should the element be cleared of children? Default true.
+ * @returns {Element}
+ */
 function puzzleElement(clear=true) {
     let e = document.querySelector("#puzzle")
     if (clear) {
@@ -16,25 +48,43 @@ function puzzleElement(clear=true) {
     return e
 }
 
-function error(message) {
-    let e = puzzleElement().appendChild(document.createElement("p"))
+/**
+ * Display an error in the puzzle area, and also send it to the console.
+ * 
+ * This makes it so the user can see a bit more about what the problem is.
+ * 
+ * @param {String} error 
+ */
+function error(error) {
+    console.error(error)
+    let e = puzzleElement().appendChild(document.createElement("pre"))
     e.classList.add("error")
-    e.textContent = message
+    e.textContent = error.Body || error
 }
 
+/**
+ * Set the answer and invoke input handlers.
+ * 
+ * This makes sure the Circle Of Success gets updated.
+ * 
+ * @param {String} s 
+ */
+function setanswer(s) {
+    let e = document.querySelector("#answer")
+    e.value = s
+    e.dispatchEvent(new Event("input"))
+}
+
+/**
+ * Load the given puzzle.
+ * 
+ * @param {String} category 
+ * @param {Number} points 
+ */
 async function loadPuzzle(category, points) {
-    let server = new moth.Server()
-    puzzle = server.GetPuzzle(category, points)
-    await puzzle.Populate()
+    console.group("Loading puzzle:", category, points)
+    let contentBase = new URL(`content/${category}/${points}/`, location)
     
-    let title = `${category} ${points}`
-    document.querySelector("title").textContent = title
-    document.querySelector("#title").textContent = title
-    document.querySelector("#authors").textContent = puzzle.Authors.join(", ")
-    puzzleElement().innerHTML = puzzle.Body
-}
-
-function hashchange() {
     // Tell user we're loading
     puzzleElement().appendChild(document.createElement("progress"))
     for (let qs of ["#authors", "#title", "title"]) {
@@ -43,6 +93,55 @@ function hashchange() {
         }
     }    
 
+    let server = new moth.Server()
+    let puzzle = server.GetPuzzle(category, points)
+    console.time("Puzzle load")
+    await puzzle.Populate()
+    console.timeEnd("Puzzle load")
+
+    let title = `${category} ${points}`
+    document.querySelector("title").textContent = title
+    document.querySelector("#title").textContent = title
+    document.querySelector("#authors").textContent = puzzle.Authors.join(", ")
+    puzzleElement().innerHTML = puzzle.Body
+
+    console.info("Adding attached scripts...")
+    for (let script of (puzzle.Scripts || [])) {
+        let st = document.createElement("script")
+        document.head.appendChild(st)
+        st.src = new URL(script, contentBase)
+      }
+
+    console.info("Listing attached files...")
+    for (let fn of (puzzle.Attachments || [])) {
+        let li = document.createElement("li")
+        let a = document.createElement("a")
+        a.href = new URL(fn, contentBase)
+        a.innerText = fn
+        li.appendChild(a)
+        document.getElementById("files").appendChild(li)
+    }
+
+
+    window.app.puzzle = puzzle
+    console.info("window.app.puzzle =", window.app.puzzle)
+
+    console.groupEnd()
+}
+
+function init() {
+    window.app = {}
+    window.setanswer = setanswer
+
+    for (let form of document.querySelectorAll("form.answer")) {
+        form.addEventListener("submit", formSubmitHandler)
+        for (let e of form.querySelectorAll("[name=answer]")) {
+            e.addEventListener("input", answerInputHandler)
+        }
+    }
+    // There isn't a more graceful way to "unload" scripts attached to the current puzzle
+    window.addEventListener("hashchange", () => location.reload())
+
     let hashpart = location.hash.split("#")[1] || ""
     let catpoints = hashpart.split(":")
     let category = catpoints[0]
@@ -56,14 +155,6 @@ function hashchange() {
     .catch(err => error(err))
 }
 
-function init() {
-    for (let e of document.querySelectorAll("form.answer")) {
-        e.addEventListener("submit", submit)
-    }
-    window.addEventListener("hashchange", hashchange)
-    hashchange()
-}
-
 if (document.readyState === "loading") {
     document.addEventListener("DOMContentLoaded", init)
 } else {