[IMP/REF] Improve and fix a lot of things:

- Add an eslint config
- Fix code to conform to the new config
- Position all elements in overlay as single block so they're well
aligned on all browsers
- Add FPS counter
- Restore ability to show the spectrum of the default file
- Make user files play in the audio editor and synchronize visuals with
that, allowing them to control the audio normally
- Removed some dead code
- Add a (probably useless) per-frame cache for FFT

.eslintrc.js

@@ -0,0 +1,320 @@
+module.exports = {
+  'env': {
+    'browser': true,
+    'es2021': true,
+  },
+  'extends': 'eslint:recommended',
+  'parserOptions': {
+    'ecmaVersion': 12,
+    'sourceType': 'module',
+  },
+  'rules': {
+    'accessor-pairs': 'error',
+    'array-bracket-newline': 'error',
+    'array-bracket-spacing': [
+      'error',
+      'never',
+    ],
+    'array-callback-return': 'error',
+    'arrow-body-style': 'error',
+    'arrow-parens': 'off',
+    'arrow-spacing': [
+      'error',
+      {
+        'after': true,
+        'before': true,
+      },
+    ],
+    'block-scoped-var': 'error',
+    'block-spacing': 'error',
+    'brace-style': [
+      'error',
+      '1tbs',
+    ],
+    'callback-return': 'error',
+    'camelcase': 'error',
+    'capitalized-comments': 'off',
+    'class-methods-use-this': 'error',
+    'comma-dangle': ['error', 'always-multiline'],
+    'comma-spacing': [
+      'error',
+      {
+        'after': true,
+        'before': false,
+      },
+    ],
+    'comma-style': [
+      'error',
+      'last',
+    ],
+    'complexity': 'error',
+    'computed-property-spacing': [
+      'error',
+      'never',
+    ],
+    'consistent-return': 'error',
+    'consistent-this': 'error',
+    'curly': 'off',
+    'default-case': 'error',
+    'default-case-last': 'error',
+    'default-param-last': 'error',
+    'dot-location': 'error',
+    'dot-notation': 'error',
+    'eol-last': [
+      'error',
+      'never',
+    ],
+    'eqeqeq': 'off',
+    'func-call-spacing': 'error',
+    'func-name-matching': 'error',
+    'func-names': 'error',
+    'func-style': [
+      'error',
+      'declaration',
+    ],
+    'function-paren-newline': 'error',
+    'generator-star-spacing': 'error',
+    'global-require': 'error',
+    'grouped-accessor-pairs': 'error',
+    'guard-for-in': 'error',
+    'handle-callback-err': 'error',
+    'id-blacklist': 'error',
+    'id-denylist': 'error',
+    'id-length': 'off',
+    'id-match': 'error',
+    'implicit-arrow-linebreak': [
+      'error',
+      'beside',
+    ],
+    'indent': ['warn', 2],
+    'init-declarations': 'off',
+    'jsx-quotes': 'error',
+    'key-spacing': 'error',
+    'keyword-spacing': [
+      'error',
+      {
+        'after': true,
+        'before': true,
+      },
+    ],
+    'line-comment-position': 'off',
+    'linebreak-style': [
+      'error',
+      'unix',
+    ],
+    'lines-around-comment': 'error',
+    'lines-around-directive': 'error',
+    'lines-between-class-members': 'error',
+    'max-classes-per-file': 'error',
+    'max-depth': 'error',
+    'max-len': 'off',
+    'max-lines-per-function': 'off',
+    'max-nested-callbacks': 'error',
+    'max-params': 'error',
+    'max-statements': 'off',
+    'max-statements-per-line': 'error',
+    'multiline-comment-style': 'error',
+    'new-cap': 'error',
+    'new-parens': 'error',
+    'newline-after-var': 'off',
+    'newline-before-return': 'off',
+    'newline-per-chained-call': 'error',
+    'no-alert': 'error',
+    'no-array-constructor': 'error',
+    'no-await-in-loop': 'error',
+    'no-bitwise': 'error',
+    'no-buffer-constructor': 'error',
+    'no-caller': 'error',
+    'no-catch-shadow': 'error',
+    'no-confusing-arrow': 'error',
+    'no-console': 'off',
+    'no-constructor-return': 'error',
+    'no-continue': 'error',
+    'no-div-regex': 'error',
+    'no-duplicate-imports': 'error',
+    'no-else-return': 'error',
+    'no-empty-function': 'error',
+    'no-eq-null': 'error',
+    'no-eval': 'error',
+    'no-extend-native': 'error',
+    'no-extra-bind': 'error',
+    'no-extra-label': 'error',
+    'no-extra-parens': 'off',
+    'no-floating-decimal': 'off',
+    'no-implicit-coercion': 'error',
+    'no-implicit-globals': 'error',
+    'no-implied-eval': 'error',
+    'no-inline-comments': 'off',
+    'no-invalid-this': 'error',
+    'no-iterator': 'error',
+    'no-label-var': 'error',
+    'no-labels': 'error',
+    'no-lone-blocks': 'error',
+    'no-lonely-if': 'error',
+    'no-loop-func': 'error',
+    'no-loss-of-precision': 'error',
+    'no-magic-numbers': 'off',
+    'no-mixed-operators': 'off',
+    'no-mixed-requires': 'error',
+    'no-multi-assign': 'error',
+    'no-multi-spaces': 'error',
+    'no-multi-str': 'error',
+    'no-multiple-empty-lines': 'error',
+    'no-native-reassign': 'error',
+    'no-negated-condition': 'off',
+    'no-negated-in-lhs': 'error',
+    'no-nested-ternary': 'error',
+    'no-new': 'error',
+    'no-new-func': 'error',
+    'no-new-object': 'error',
+    'no-new-require': 'error',
+    'no-new-wrappers': 'error',
+    'no-nonoctal-decimal-escape': 'error',
+    'no-octal-escape': 'error',
+    'no-param-reassign': 'error',
+    'no-path-concat': 'error',
+    'no-plusplus': [
+      'error',
+      {
+        'allowForLoopAfterthoughts': true,
+      },
+    ],
+    'no-process-env': 'error',
+    'no-process-exit': 'error',
+    'no-promise-executor-return': 'error',
+    'no-proto': 'error',
+    'no-restricted-exports': 'error',
+    'no-restricted-globals': 'error',
+    'no-restricted-imports': 'error',
+    'no-restricted-modules': 'error',
+    'no-restricted-properties': 'error',
+    'no-restricted-syntax': 'error',
+    'no-return-assign': 'error',
+    'no-return-await': 'error',
+    'no-script-url': 'error',
+    'no-self-compare': 'error',
+    'no-sequences': 'error',
+    'no-shadow': 'error',
+    'no-spaced-func': 'error',
+    'no-sync': 'error',
+    'no-tabs': 'error',
+    'no-template-curly-in-string': 'error',
+    'no-ternary': 'off',
+    'no-throw-literal': 'error',
+    'no-trailing-spaces': 'error',
+    'no-undef-init': 'error',
+    'no-undefined': 'error',
+    'no-underscore-dangle': 'error',
+    'no-unmodified-loop-condition': 'error',
+    'no-unneeded-ternary': 'error',
+    'no-unreachable-loop': 'error',
+    'no-unsafe-optional-chaining': 'error',
+    'no-unused-expressions': 'error',
+    'no-use-before-define': 'off',
+    'no-useless-backreference': 'error',
+    'no-useless-call': 'error',
+    'no-useless-computed-key': 'error',
+    'no-useless-concat': 'error',
+    'no-useless-constructor': 'error',
+    'no-useless-rename': 'error',
+    'no-useless-return': 'error',
+    'no-var': 'error',
+    'no-void': 'error',
+    'no-warning-comments': 'off',
+    'no-whitespace-before-property': 'error',
+    'object-curly-newline': 'error',
+    'object-curly-spacing': 'error',
+    'object-property-newline': 'error',
+    'object-shorthand': 'off',
+    'one-var': 'off',
+    'one-var-declaration-per-line': [
+      'error',
+      'initializations',
+    ],
+    'operator-assignment': [
+      'error',
+      'always',
+    ],
+    'operator-linebreak': 'error',
+    'padded-blocks': 'off',
+    'padding-line-between-statements': 'error',
+    'prefer-arrow-callback': 'error',
+    'prefer-const': 'off',
+    'prefer-destructuring': 'error',
+    'prefer-exponentiation-operator': 'off',
+    'prefer-named-capture-group': 'error',
+    'prefer-numeric-literals': 'error',
+    'prefer-object-spread': 'error',
+    'prefer-promise-reject-errors': 'error',
+    'prefer-reflect': 'error',
+    'prefer-regex-literals': 'error',
+    'prefer-rest-params': 'error',
+    'prefer-spread': 'error',
+    'prefer-template': 'error',
+    'quote-props': 'off',
+    'quotes': [
+      'error',
+      'single',
+    ],
+    'radix': 'error',
+    'require-atomic-updates': 'error',
+    'require-await': 'off',
+    'require-jsdoc': 'off',
+    'require-unicode-regexp': 'error',
+    'rest-spread-spacing': [
+      'error',
+      'never',
+    ],
+    'semi': 'off',
+    'semi-spacing': [
+      'error',
+      {
+        'after': true,
+        'before': false,
+      },
+    ],
+    'semi-style': [
+      'error',
+      'last',
+    ],
+    'sort-imports': 'error',
+    'sort-keys': [
+      'error',
+      'asc',
+    ],
+    'sort-vars': 'error',
+    'space-before-blocks': 'error',
+    'space-before-function-paren': 'off',
+    'space-in-parens': [
+      'error',
+      'never',
+    ],
+    'space-infix-ops': 'error',
+    'space-unary-ops': 'error',
+    'spaced-comment': [
+      'error',
+      'always',
+    ],
+    'strict': 'error',
+    'switch-colon-spacing': 'error',
+    'symbol-description': 'error',
+    'template-curly-spacing': [
+      'error',
+      'never',
+    ],
+    'template-tag-spacing': 'error',
+    'unicode-bom': [
+      'error',
+      'never',
+    ],
+    'valid-jsdoc': 'error',
+    'vars-on-top': 'error',
+    'wrap-iife': 'error',
+    'wrap-regex': 'error',
+    'yield-star-spacing': 'error',
+    'yoda': [
+      'error',
+      'never',
+    ],
+  },
+};

.gitignore

@@ -1,5 +1,3 @@
 /node_modules/*
 /.cache/*
 /dist/*
-/assets/audio/*
-!/assets/audio/Komiku - Mushrooms.mp3

docs/index.html

@@ -1 +1 @@
-<html><head><meta http-equiv="content-type" content="text/html; charset=utf-8"><title></title><link rel="stylesheet" href="style.1f4888d2.css"></head><body> <canvas></canvas> <script src="src.484009ad.js" charset="utf-8"></script> </body></html>
+<html><head><meta http-equiv="content-type" content="text/html; charset=utf-8"><title></title><link rel="stylesheet" href="style.6b72d3b2.css"></head><body> <canvas></canvas> <div class="overlay"> <audio controls src="Komiku - Mushrooms.4767492c.mp3" loop></audio> <label for="">Choose a file (will be processed locally) <input type="file" name="" value=""> </label> </div> <script src="src.b180bbfd.js" charset="utf-8"></script> </body></html>