🎉 add tvglitch effect - adds the TV effect to glitch

src/TVGlitch.js

@@ -0,0 +1,120 @@
+//////////////////////////////////////////////////////////////////////////////////////////
+//          )                                                   (                       //
+//       ( /(   (  (               )    (       (  (  (         )\ )    (  (            //
+//       )\()) ))\ )(   (         (     )\ )    )\))( )\  (    (()/( (  )\))(  (        //
+//      ((_)\ /((_|()\  )\ )      )\  '(()/(   ((_)()((_) )\ )  ((_)))\((_)()\ )\       //
+//      | |(_|_))( ((_)_(_/(    _((_))  )(_))  _(()((_|_)_(_/(  _| |((_)(()((_|(_)      //
+//      | '_ \ || | '_| ' \))  | '  \()| || |  \ V  V / | ' \)) _` / _ \ V  V (_-<      //
+//      |_.__/\_,_|_| |_||_|   |_|_|_|  \_, |   \_/\_/|_|_||_|\__,_\___/\_/\_//__/      //
+//                                 |__/                                                 //
+//////////////////////////////////////////////////////////////////////////////////////////
+
+// SPDX-FileCopyrightText: Simon Schneegans <code@simonschneegans.de>
+// SPDX-License-Identifier: GPL-3.0-or-later
+
+'use strict';
+
+const GObject = imports.gi.GObject;
+
+const _ = imports.gettext.domain('burn-my-windows').gettext;
+
+const ExtensionUtils = imports.misc.extensionUtils;
+const Me             = imports.misc.extensionUtils.getCurrentExtension();
+const utils          = Me.imports.src.utils;
+const ShaderFactory  = Me.imports.src.ShaderFactory.ShaderFactory;
+
+//////////////////////////////////////////////////////////////////////////////////////////
+// This effect applies some intentional graphics issues to your windows.                //
+//////////////////////////////////////////////////////////////////////////////////////////
+
+// The effect class can be used to get some metadata (like the effect's name or supported
+// GNOME Shell versions), to initialize the respective page of the settings dialog, as
+// well as to create the actual shader for the effect.
+var Glitch = class {
+
+  // The constructor creates a ShaderFactory which will be used by extension.js to create
+  // shader instances for this effect. The shaders will be automagically created using the
+  // GLSL file in resources/shaders/<nick>.glsl. The callback will be called for each
+  // newly created shader instance.
+  constructor() {
+    this.shaderFactory = new ShaderFactory(this.getNick(), (shader) => {
+      // We import Clutter in this function as it is not available in the preferences
+      // process. This creator function of the ShaderFactory is only called within GNOME
+      // Shell's process.
+      const Clutter = imports.gi.Clutter;
+
+      // Store uniform locations of newly created shaders.
+      shader._uSeed     = shader.get_uniform_location('uSeed');
+      shader._uColor    = shader.get_uniform_location('uColor');
+      shader._uScale    = shader.get_uniform_location('uScale');
+      shader._uStrength = shader.get_uniform_location('uStrength');
+      shader._uSpeed    = shader.get_uniform_location('uSpeed');
+
+      // Write all uniform values at the start of each animation.
+      shader.connect('begin-animation', (shader, settings) => {
+        const c = Clutter.Color.from_string(settings.get_string('glitch-color'))[1];
+
+        // If we are performing an integration tests, we use a fixed seed.
+        const testMode = settings.get_boolean('test-mode');
+
+        // clang-format off
+        shader.set_uniform_float(shader._uSeed,  1, [testMode ? 0 : Math.random()]);
+        shader.set_uniform_float(shader._uColor, 3, [c.red / 255, c.green / 255, c.blue / 255]);
+        shader.set_uniform_float(shader._uScale, 1, [settings.get_double('glitch-scale')]);
+        shader.set_uniform_float(shader._uStrength, 1, [settings.get_double('glitch-strength')]);
+        shader.set_uniform_float(shader._uSpeed, 1, [settings.get_double('glitch-speed')]);
+        // clang-format on
+      });
+    });
+  }
+
+  // ---------------------------------------------------------------------------- metadata
+
+  // The effect is available on all GNOME Shell versions supported by this extension.
+  getMinShellVersion() {
+    return [3, 36];
+  }
+
+  // This will be called in various places where a unique identifier for this effect is
+  // required. It should match the prefix of the settings keys which store whether the
+  // effect is enabled currently (e.g. '*-close-effect'), and its animation time
+  // (e.g. '*-animation-time').
+  getNick() {
+    return 'tvglitch';
+  }
+
+  // This will be shown in the sidebar of the preferences dialog as well as in the
+  // drop-down menus where the user can choose the effect.
+  getLabel() {
+    return _('TVGlitch');
+  }
+
+  // -------------------------------------------------------------------- API for prefs.js
+
+  // This is called by the preferences dialog. It loads the settings page for this effect,
+  // and binds all properties to the settings.
+  getPreferences(dialog) {
+
+    // Add the settings page to the builder.
+    dialog.getBuilder().add_from_resource(`/ui/${utils.getUIDir()}/TVGlitch.ui`);
+
+    // Bind all properties.
+    dialog.bindAdjustment('glitch-animation-time');
+    dialog.bindAdjustment('glitch-scale');
+    dialog.bindAdjustment('glitch-speed');
+    dialog.bindAdjustment('glitch-strength');
+    dialog.bindColorButton('glitch-color');
+
+    // Finally, return the new settings page.
+    return dialog.getBuilder().get_object('tvglitch-prefs');
+  }
+
+  // ---------------------------------------------------------------- API for extension.js
+
+  // The getActorScale() is called from extension.js to adjust the actor's size during the
+  // animation. This is useful if the effect requires drawing something beyond the usual
+  // bounds of the actor. This only works for GNOME 3.38+.
+  getActorScale(settings) {
+    return {x: 1.0, y: 1.0};
+  }
+}