Just some twiddling

theme/background.mjs

@@ -4,6 +4,7 @@ function randint(max) {
 
 const MILLISECOND = 1
 const SECOND = MILLISECOND * 1000
+const FRAMERATE = 24 / SECOND  // Fast enough for this tomfoolery
 
 class Point {
     constructor(x, y) {
@@ -87,7 +88,7 @@ class QixLine {
  * like the video game "qix"
  */
 class QixBackground {
-    constructor(ctx, frameInterval = SECOND/6) {
+    constructor(ctx, frameRate = 6/SECOND) {
         this.ctx = ctx
         this.min = new Point(0, 0)
         this.max = new Point(this.ctx.canvas.width, this.ctx.canvas.height)
@@ -95,7 +96,7 @@ class QixBackground {
 
         this.lines = [
             new QixLine(
-                0,
+                Math.random(),
                 new Point(randint(this.box.x), randint(this.box.y)),
                 new Point(randint(this.box.x), randint(this.box.y)),
             )
@@ -109,7 +110,7 @@ class QixBackground {
             new Point(1 + randint(this.box.x / 100), 1 + randint(this.box.y / 100)),
         )
 
-        this.frameInterval = frameInterval
+        this.frameInterval = MILLISECOND / frameRate
         this.nextFrame = 0
     }
 
@@ -157,8 +158,8 @@ function init() {
     let ctx = canvas.getContext("2d")
 
     let qix = new QixBackground(ctx)
-    setInterval(() => qix.Animate(), SECOND/6)
-
+    // window.requestAnimationFrame is overkill for something this silly
+    setInterval(() => qix.Animate(), MILLISECOND/FRAMERATE)
 }
 
 if (document.readyState === "loading") {

theme/basic.css

@@ -74,6 +74,7 @@ p {
 }
 form, pre {
 	margin: 1em;
+  overflow-x: auto;
 }
 input, select {
 	padding: 0.6em;

theme/hash.mjs

@@ -1,20 +0,0 @@
-// 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

@@ -15,7 +15,7 @@ class Hash {
         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
+            h = ((h * 33) + c) >>> 0
         }
         return h
     }
@@ -29,7 +29,7 @@ class Hash {
     static djb2xor(buf) {
         let h = 5381
         for (let c of (new TextEncoder()).encode(buf)) {
-            h = h * 33 ^ c
+            h = ((h * 33) ^ c) >>> 0
         }
         return h
     }
@@ -40,7 +40,7 @@ class Hash {
      * Used until MOTH v4.5
      * 
      * @param {String} buf Input
-     * @returns {String} hex-encoded digest
+     * @returns {Promise.<String>} hex-encoded digest
      */
     static async sha256(buf) {
         const msgUint8 = new TextEncoder().encode(buf)
@@ -55,9 +55,23 @@ class Hash {
    * @param {Number[]} buf Byte array
    * @returns {String}
    */
-  static async hexlify(buf) {
+  static hexlify(buf) {
     return buf.map(b => b.toString(16).padStart(2, "0")).join("")   
   }
+
+  /**
+   * Apply every hash to the input buffer.
+   * 
+   * @param {String} buf Input
+   * @returns {Promise.<String[]>}
+   */
+  static async All(buf) {
+    return [
+        String(this.djb2(buf)),
+        String(this.djb2xor(buf)),
+        await this.sha256(buf),
+    ]
+  }
 }
 
 /**
@@ -166,12 +180,24 @@ class Puzzle {
         return this.server.GetContent(this.Category, this.Points, filename)
     }
 
+    /**
+     * Check if a string is possibly correct.
+     *
+     * The server sends a list of answer hashes with each puzzle: this method
+     * checks to see if any of those hashes match a hash of the string.
+     *
+     * The MOTH development team likes obscure hash functions with a lot of
+     * collisions, which means that a given input may match another possible
+     * string's hash. We do this so that if you run a brute force attack against
+     * the list of hashes, you have to write your own brute force program, and
+     * you still have to pick through a lot of potentially correct answers when
+     * it's done.
+     *
+     * @param {String} str User-submitted possible answer
+     * @returns {Promise.<Boolean>}
+     */
     async IsPossiblyCorrect(str) {
-        let userAnswerHashes = [
-            Hash.djb2(str),
-            Hash.djb2xor(str),
-            await Hash.sha256(str),
-        ]
+        let userAnswerHashes = await Hash.All(str)
 
         for (let pah of this.AnswerHashes) {
             for (let uah of userAnswerHashes) {

theme/puzzle.mjs

@@ -95,9 +95,9 @@ async function loadPuzzle(category, points) {
 
     let server = new moth.Server()
     let puzzle = server.GetPuzzle(category, points)
-    console.time("Puzzle load")
+    console.time("Populate")
     await puzzle.Populate()
-    console.timeEnd("Puzzle load")
+    console.timeEnd("Populate")
 
     let title = `${category} ${points}`
     document.querySelector("title").textContent = title
@@ -122,6 +122,8 @@ async function loadPuzzle(category, points) {
         document.getElementById("files").appendChild(li)
     }
 
+    let baseElement = document.head.appendChild(document.createElement("base"))
+    baseElement.href = contentBase
 
     window.app.puzzle = puzzle
     console.info("window.app.puzzle =", window.app.puzzle)
@@ -142,6 +144,11 @@ function init() {
     // There isn't a more graceful way to "unload" scripts attached to the current puzzle
     window.addEventListener("hashchange", () => location.reload())
 
+    // Make all links absolute, because we're going to be changing the base URL
+    for (let e of document.querySelectorAll("[href]")) {
+        e.href = new URL(e.href, location)
+    }
+
     let hashpart = location.hash.split("#")[1] || ""
     let catpoints = hashpart.split(":")
     let category = catpoints[0]