fix: clear canvas

LICENSE

@@ -187,7 +187,7 @@
       same "printed page" as the copyright notice for easier
       identification within third-party archives.
 
-   Copyright [yyyy] [name of copyright owner]
+   Copyright 2024 Andrey DarkCat09
 
    Licensed under the Apache License, Version 2.0 (the "License");
    you may not use this file except in compliance with the License.

script.js

@@ -16,6 +16,8 @@ addEventListener('DOMContentLoaded', () => {
 
     canvas.width = canvas.height = size * scale
 
+    ctx.clearRect(0, 0, canvas.width, canvas.height)
+
     for (let row = 0; row < size; row++) {
       for (let col = 0; col < size; col++) {
         if (eval(mask) == 0) {