First commit.

Signed-off-by: Chen Xiao <abigwc@gmail.com>

client/node_modules/roughjs/bin/math.js

@@ -0,0 +1,16 @@
+export function randomSeed() {
+    return Math.floor(Math.random() * 2 ** 31);
+}
+export class Random {
+    constructor(seed) {
+        this.seed = seed;
+    }
+    next() {
+        if (this.seed) {
+            return ((2 ** 31 - 1) & (this.seed = Math.imul(48271, this.seed))) / 2 ** 31;
+        }
+        else {
+            return Math.random();
+        }
+    }
+}