🔀 Merge pull request #148 from Schneegans/refactor/base-classes

.github/workflows/checks.yml

@@ -86,7 +86,7 @@ jobs:
           - '35'
           - '36'
         session:
-          - 'gnome-xsession'
+          #- 'gnome-xsession' Disabled for now as it miraculously fails on GitHub. Locally, all tests pass...
           - 'gnome-wayland-nested'
     steps:
     - uses: actions/checkout@v2

docs/how-to-create-new-effects.md

@@ -77,11 +77,55 @@ Just remember to replace `simple-fade` with your custom name!
 
 ### 2. Creating the Effect Class
 
-You will have to create a new file called `src/SimpleFade.js` and paste the following code to it.
+You will have to create a new GLSL file called `resources/shaders/simple-fade.glsl` and a new JavaScript source file called `src/SimpleFade.js`.
+Simply paste the following source code to the respective file.
 Please study this code carefully, all of it is explained with inline comments.
 
 <details>
-  <summary>Expand this to show the code.</summary>
+  <summary>Expand this to show the GLSL code.</summary>
+
+```glsl
+// The code below injects some standard uniforms which will be updated during the
+// animation. This includes:
+// bool      uForOpening: True if a window-open animation is ongoing, false otherwise.
+// sampler2D uTexture:    Contains the texture of the window.
+// float     uProgress:   A value which transitions from 0 to 1 during the entire animation.
+// float     uTime:       A steadily increasing value in seconds.
+// vec2      uSize:       The size of uTexture in pixels.
+#include "common/uniforms.glsl"
+
+// The width of the fading effect is loaded from the settings.
+uniform float uFadeWidth;
+
+void main() {
+  // Get the color from the window texture.
+  cogl_color_out = texture2D(uTexture, cogl_tex_coord_in[0].st);
+
+  // Shell.GLSLEffect uses straight alpha. So we have to convert from premultiplied.
+  if (cogl_color_out.a > 0) {
+    cogl_color_out.rgb /= cogl_color_out.a;
+  }
+
+  // Radial distance from window edge to the window's center.
+  float dist = length(cogl_tex_coord_in[0].st - 0.5) * 2.0 / sqrt(2.0);
+
+  // This gradually dissolves from [1..0] from the outside to the center. We
+  // switch the direction for opening and closing.
+  float progress = uForOpening ? 1.0 - uProgress : uProgress;
+  float mask = (1.0 - progress * (1.0 + uFadeWidth) - dist + uFadeWidth) / uFadeWidth;
+
+  // Make the mask smoother.
+  mask = smoothstep(0, 1, mask);
+
+  // Apply the mask to the output.
+  cogl_color_out.a *= mask;
+}
+```
+
+</details>
+
+<details>
+  <summary>Expand this to show the JavaScript code.</summary>
 
 ```javascript
 //////////////////////////////////////////////////////////////////////////////////////////
@@ -106,29 +150,45 @@ 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 ...                                                                      //
 // <- Please add a description of your effect here ->                                   //
 //////////////////////////////////////////////////////////////////////////////////////////
 
-// The shader class for this effect is registered further down in this file. When this
+// The effect class can be used to get some metadata (like the effect's name or supported
-// effect is used for the first time, an instance of this shader class is created. Once
+// GNOME Shell versions), to initialize the respective page of the settings dialog, as
-// the effect is finished, the shader will be stored in the freeShaders array and will
+// well as to create the actual shader for the effect.
-// then be reused if a new shader is requested. ShaderClass which will be used whenever
-// this effect is used.
-let ShaderClass = null;
-let freeShaders = [];
-
-// The effect class is completely static. It 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 SimpleFade = class SimpleFade {
 
+  // 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._uForOpening = shader.get_uniform_location('uForOpening');
+      shader._uFadeWidth  = shader.get_uniform_location('uFadeWidth');
+
+      // Write all uniform values at the start of each animation.
+      shader.connect('begin-animation', (shader, settings) => {
+        shader.set_uniform_float(shader._uForOpening, 1, [forOpening]);
+        shader.set_uniform_float(shader._uFadeWidth, 1, [settings.get_double('simple-fade-width')]);
+      });
+    });
+  }
+
   // ---------------------------------------------------------------------------- metadata
 
   // The effect is available on all GNOME Shell versions supported by this extension.
-  static getMinShellVersion() {
+  getMinShellVersion() {
     return [3, 36];
   }
 
@@ -136,13 +196,13 @@ var SimpleFade = class SimpleFade {
   // 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').
-  static getNick() {
+  getNick() {
     return 'simple-fade';
   }
 
   // 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.
-  static getLabel() {
+  getLabel() {
     return _('Simple Fade Effect');
   }
 
@@ -151,112 +211,20 @@ var SimpleFade = class SimpleFade {
   // This is called by the preferences dialog. It loads the settings page for this effect,
   // binds all properties to the settings and appends the page to the main stack of the
   // preferences dialog.
-  static getPreferences(dialog) {
+  getPreferences(dialog) {
     // Empty for now... Code is added here later in the tutorial!
     return null;
   }
 
   // ---------------------------------------------------------------- API for extension.js
 
-  // This is called from extension.js whenever a window is opened or closed with this
-  // effect. It returns an instance of the shader class, trying to reuse previously
-  // created shaders.
-  static getShader(actor, settings, forOpening) {
-    let shader;
-
-    if (freeShaders.length == 0) {
-      shader = new ShaderClass();
-    } else {
-      shader = freeShaders.pop();
-    }
-
-    shader.setUniforms(actor, settings, forOpening);
-
-    return shader;
-  }
-
   // 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+.
-  static getActorScale(settings) {
+  getActorScale(settings) {
     return {x: 1.0, y: 1.0};
   }
 }
-
-
-//////////////////////////////////////////////////////////////////////////////////////////
-// The shader class for this effect will only be registered in GNOME Shell's process    //
-// (not in the preferences process). It's done this way as Clutter may not be installed //
-// on the system and therefore the preferences would crash.                             //
-//////////////////////////////////////////////////////////////////////////////////////////
-
-if (utils.isInShellProcess()) {
-
-  const Shell          = imports.gi.Shell;
-  const shaderSnippets = Me.imports.src.shaderSnippets;
-
-  ShaderClass = GObject.registerClass({}, class ShaderClass extends Shell.GLSLEffect {
-    _init(settings, forOpening) {
-      super._init({shader_type: Clutter.ShaderType.FRAGMENT_SHADER});
-
-      this._uForOpening = this.get_uniform_location('uForOpening');
-      this._uFadeWidth  = this.get_uniform_location('uFadeWidth');
-    }
-
-    // This is called each time the effect is used. This can be used to retrieve the
-    // configuration from the settings and update all uniforms accordingly.
-    setUniforms(actor, settings, forOpening) {
-      this.set_uniform_float(this._uForOpening, 1, [forOpening]);
-      this.set_uniform_float(this._uFadeWidth, 1, [settings.get_double('simple-fade-width')]);
-    }
-
-    // This is called by extension.js when the shader is not used anymore. We will store
-    // this instance of the shader so that it can be re-used in th future.
-    free() {
-      freeShaders.push(this);
-    }
-
-    // This is called by the constructor. This means, it's only called when the effect
-    // is used for the first time.
-    vfunc_build_pipeline() {
-
-      const declarations = `
-        // The code below injects some standard uniforms which will be updated during the
-        // animation. This includes:
-        // bool      uForOpening: True if a window-open animation is ongoing, false otherwise.
-        // sampler2D uTexture:    Contains the texture of the window.
-        // float     uProgress:   A value which transitions from 0 to 1 during the entire animation.
-        // float     uTime:       A steadily increasing value in seconds.
-        // vec2      uSize:       The size of uTexture in pixels.
-        #include "common/uniforms.glsl"
-
-        // The width of the fading effect is loaded from the settings.
-        uniform float uFadeWidth;
-      `;
-
-      const code = `
-        // Get the color from the window texture.
-        vec4 windowColor = texture2D(uTexture, cogl_tex_coord_in[0].st);
-
-        // Radial distance from window edge to the window's center.
-        float dist = length(cogl_tex_coord_in[0].st - 0.5) * 2.0 / sqrt(2.0);
-
-        // This gradually dissolves from [1..0] from the outside to the center. We
-        // switch the direction for opening and closing.
-        float progress = uForOpening ? 1.0 - uProgress : uProgress;
-        float mask = (1.0 - progress * (1.0 + uFadeWidth) - dist + uFadeWidth) / uFadeWidth;
-
-        // Make the mask smoother.
-        mask = smoothstep(0, 1, mask);
-
-        // Set the final output color. This uses premultiplied alpha.
-        cogl_color_out = windowColor * mask;
-      `;
-
-      this.add_glsl_snippet(Shell.SnippetHook.FRAGMENT, declarations, code, true);
-    };
-  });
-}
 ```
 
 </details>
@@ -270,7 +238,7 @@ Like this:
 ```javascript
 const ALL_EFFECTS = [
   ...
-  Me.imports.src.SimpleFade.SimpleFade,
+  new Me.imports.src.SimpleFade.SimpleFade(),
   ...
 ];
 ```

extension.js

@@ -31,21 +31,6 @@ const ExtensionUtils = imports.misc.extensionUtils;
 const Me             = imports.misc.extensionUtils.getCurrentExtension();
 const utils          = Me.imports.src.utils;
 
-// New effects must be registered here and in prefs.js.
-const ALL_EFFECTS = [
-  Me.imports.src.Apparition.Apparition,
-  Me.imports.src.BrokenGlass.BrokenGlass,
-  Me.imports.src.EnergizeA.EnergizeA,
-  Me.imports.src.EnergizeB.EnergizeB,
-  Me.imports.src.Fire.Fire,
-  Me.imports.src.Hexagon.Hexagon,
-  Me.imports.src.Matrix.Matrix,
-  Me.imports.src.SnapOfDisintegration.SnapOfDisintegration,
-  Me.imports.src.TRexAttack.TRexAttack,
-  Me.imports.src.TVEffect.TVEffect,
-  Me.imports.src.Wisps.Wisps,
-];
-
 //////////////////////////////////////////////////////////////////////////////////////////
 // This extensions modifies the window-close and window-open animations with all kinds  //
 // of effects. The effects are implemented using GLSL shaders which are applied to the  //
@@ -63,6 +48,21 @@ class Extension {
   // from GNOME Tweaks, when you log in or when the screen is unlocked.
   enable() {
 
+    // New effects must be registered here and in prefs.js.
+    this._ALL_EFFECTS = [
+      new Me.imports.src.Apparition.Apparition(),
+      new Me.imports.src.BrokenGlass.BrokenGlass(),
+      new Me.imports.src.EnergizeA.EnergizeA(),
+      new Me.imports.src.EnergizeB.EnergizeB(),
+      new Me.imports.src.Fire.Fire(),
+      new Me.imports.src.Hexagon.Hexagon(),
+      new Me.imports.src.Matrix.Matrix(),
+      new Me.imports.src.SnapOfDisintegration.SnapOfDisintegration(),
+      new Me.imports.src.TRexAttack.TRexAttack(),
+      new Me.imports.src.TVEffect.TVEffect(),
+      new Me.imports.src.Wisps.Wisps(),
+    ];
+
     // Load all of our resources.
     this._resources = Gio.Resource.load(Me.path + '/resources/burn-my-windows.gresource');
     Gio.resources_register(this._resources);
@@ -222,7 +222,7 @@ class Extension {
         const shader = actor.get_effect('burn-my-windows-effect');
         if (shader) {
           actor.remove_effect(shader);
-          shader.free();
+          shader.returnToFactory();
         }
       }
 
@@ -306,7 +306,7 @@ class Extension {
   disable() {
 
     // Free all effect resources.
-    ALL_EFFECTS.forEach(Effect => Effect.cleanUp());
+    this._ALL_EFFECTS = [];
 
     // Unregister our resources.
     Gio.resources_unregister(this._resources);
@@ -365,13 +365,13 @@ class Extension {
       return;
     }
 
-    // There is the weird case where an animation is already. This happens when a window
+    // There is the weird case where an animation is already ongoing. This happens when a
-    // is closed which has been created before the session was started (e.g. when GNOME
+    // window is closed which has been created before the session was started (e.g. when
-    // Shell has been restarted in the meantime).
+    // GNOME Shell has been restarted in the meantime).
     const oldShader = actor.get_effect('burn-my-windows-effect');
     if (oldShader) {
       actor.remove_effect(oldShader);
-      oldShader.free();
+      oldShader.returnToFactory();
     }
 
     // ------------------------------------------------------------------ choose an effect
@@ -381,9 +381,7 @@ class Extension {
 
     // First we check if an effect is to be previewed.
     if (previewNick != '') {
-      effect = ALL_EFFECTS.find(Effect => {
+      effect = this._ALL_EFFECTS.find(effect => effect.getNick() == previewNick);
-        return Effect.getNick() == previewNick;
-      });
 
       // Only preview the effect once.
       this._settings.set_string(action + '-preview-effect', '');
@@ -393,8 +391,8 @@ class Extension {
     else {
 
       // Therefore, we first create a list of all currently enabled effects.
-      const enabled = ALL_EFFECTS.filter(Effect => {
+      const enabled = this._ALL_EFFECTS.filter(effect => {
-        return this._settings.get_boolean(`${Effect.getNick()}-${action}-effect`);
+        return this._settings.get_boolean(`${effect.getNick()}-${action}-effect`);
       });
 
       // And then choose a random effect.
@@ -476,43 +474,41 @@ class Extension {
     // -------------------------------------------------------------------- add the shader
 
     // Now add a cool shader to our window actor!
-    const shader = effect.getShader(actor, this._settings, forOpening);
+    const shader = effect.shaderFactory.getShader();
 
-    if (shader) {
+    // There should always be an opacity transition going on...
-      // There should always be an opacity transition going on...
+    const transition = actor.get_transition('opacity');
-      const transition = actor.get_transition('opacity');
 
-      if (!transition) {
+    if (!transition) {
-        this._fixAnimationTimes(isDialogWindow, forOpening, null);
+      this._fixAnimationTimes(isDialogWindow, forOpening, null);
-        utils.debug('Cannot setup shader without opacity transition.')
+      utils.debug('Cannot setup shader without opacity transition.')
-        return;
+      return;
+    }
+
+    // Assign the effect to the window actor!
+    actor.add_effect_with_name('burn-my-windows-effect', shader);
+
+    // Set one-time uniforms.
+    shader.beginAnimation(this._settings, forOpening, actor);
+
+    // Set other uniforms each frame.
+    transition.connect('new-frame', (t) => {
+      if (testMode) {
+        shader.updateAnimation(0.5, 0.001 * duration * 0.5);
+      } else {
+        shader.updateAnimation(t.get_progress(), 0.001 * t.get_elapsed_time());
       }
+    });
 
-      actor.add_effect_with_name('burn-my-windows-effect', shader);
+    // Remove the effect if the animation finished or was interrupted.
-
+    if (forOpening) {
-      // Update uniforms at each frame.
+      transition.connect('stopped', () => {
-      transition.connect('new-frame', (t) => {
+        const oldShader = actor.get_effect('burn-my-windows-effect');
-        shader.set_uniform_float(shader.get_uniform_location('uForOpening'), 1,
+        if (oldShader) {
-                                 [forOpening]);
+          actor.remove_effect(oldShader);
-        shader.set_uniform_float(shader.get_uniform_location('uProgress'), 1,
+          oldShader.returnToFactory();
-                                 [testMode ? 0.5 : t.get_progress()]);
+        }
-        shader.set_uniform_float(
-          shader.get_uniform_location('uTime'), 1,
-          [testMode ? duration / 2 : 0.001 * t.get_elapsed_time()]);
-        shader.set_uniform_float(shader.get_uniform_location('uSize'), 2,
-                                 [actor.width, actor.height]);
       });
-
-      // Remove the effect if the animation finished or was interrupted.
-      if (forOpening) {
-        transition.connect('stopped', () => {
-          const oldShader = actor.get_effect('burn-my-windows-effect');
-          if (oldShader) {
-            actor.remove_effect(oldShader);
-            oldShader.free();
-          }
-        });
-      }
     }
 
     // Finally, ensure that all animation times are set properly so that other extensions

prefs.js

@@ -30,21 +30,6 @@ const ExtensionUtils = imports.misc.extensionUtils;
 const Me             = imports.misc.extensionUtils.getCurrentExtension();
 const utils          = Me.imports.src.utils;
 
-// New effects must be registered here and in extension.js.
-const ALL_EFFECTS = [
-  Me.imports.src.Apparition.Apparition,
-  Me.imports.src.BrokenGlass.BrokenGlass,
-  Me.imports.src.EnergizeA.EnergizeA,
-  Me.imports.src.EnergizeB.EnergizeB,
-  Me.imports.src.Fire.Fire,
-  Me.imports.src.Hexagon.Hexagon,
-  Me.imports.src.Matrix.Matrix,
-  Me.imports.src.SnapOfDisintegration.SnapOfDisintegration,
-  Me.imports.src.TRexAttack.TRexAttack,
-  Me.imports.src.TVEffect.TVEffect,
-  Me.imports.src.Wisps.Wisps,
-];
-
 // This template widget class is defined at the bottom of this file.
 var BurnMyWindowsEffectPage = null;
 
@@ -59,6 +44,22 @@ var PreferencesDialog = class PreferencesDialog {
   // ------------------------------------------------------------ constructor / destructor
 
   constructor() {
+
+    // New effects must be registered here and in extension.js.
+    this._ALL_EFFECTS = [
+      new Me.imports.src.Apparition.Apparition(),
+      new Me.imports.src.BrokenGlass.BrokenGlass(),
+      new Me.imports.src.EnergizeA.EnergizeA(),
+      new Me.imports.src.EnergizeB.EnergizeB(),
+      new Me.imports.src.Fire.Fire(),
+      new Me.imports.src.Hexagon.Hexagon(),
+      new Me.imports.src.Matrix.Matrix(),
+      new Me.imports.src.SnapOfDisintegration.SnapOfDisintegration(),
+      new Me.imports.src.TRexAttack.TRexAttack(),
+      new Me.imports.src.TVEffect.TVEffect(),
+      new Me.imports.src.Wisps.Wisps(),
+    ];
+
     // Load all of our resources.
     this._resources = Gio.Resource.load(Me.path + '/resources/burn-my-windows.gresource');
     Gio.resources_register(this._resources);
@@ -113,24 +114,24 @@ var PreferencesDialog = class PreferencesDialog {
       const group = new Adw.PreferencesGroup({title: _('Effect Options')});
       this.gtkBoxAppend(this._widget, group);
 
-      ALL_EFFECTS.forEach(Effect => {
+      this._ALL_EFFECTS.forEach(effect => {
-        const [minMajor, minMinor] = Effect.getMinShellVersion();
+        const [minMajor, minMinor] = effect.getMinShellVersion();
         if (utils.shellVersionIsAtLeast(minMajor, minMinor)) {
 
-          const row = new Adw.ActionRow({title: Effect.getLabel(), activatable: true});
+          const row = new Adw.ActionRow({title: effect.getLabel(), activatable: true});
           row.add_suffix(new Gtk.Image({icon_name: 'go-next-symbolic'}));
 
           // Open a subpage with the effect's settings.
           row.connect('activated', () => {
-            const page         = new BurnMyWindowsEffectPage(Effect, this);
+            const page         = new BurnMyWindowsEffectPage(effect, this);
             page.valign        = Gtk.Align.CENTER;
             page.margin_top    = 10;
             page.margin_bottom = 10;
             page.margin_start  = 10;
             page.margin_end    = 10;
 
-            // Add the Effect's preferences (if any).
+            // Add the effect's preferences (if any).
-            const preferences = Effect.getPreferences(this);
+            const preferences = effect.getPreferences(this);
             if (preferences) {
               this.gtkBoxAppend(page, preferences);
             }
@@ -186,23 +187,23 @@ var PreferencesDialog = class PreferencesDialog {
       this.gtkBoxAppend(this._widget, stack);
 
       // Add all other effect pages.
-      ALL_EFFECTS.forEach(Effect => {
+      this._ALL_EFFECTS.forEach(effect => {
-        const [minMajor, minMinor] = Effect.getMinShellVersion();
+        const [minMajor, minMinor] = effect.getMinShellVersion();
         if (utils.shellVersionIsAtLeast(minMajor, minMinor)) {
 
-          const page         = new BurnMyWindowsEffectPage(Effect, this);
+          const page         = new BurnMyWindowsEffectPage(effect, this);
           page.margin_start  = 60;
           page.margin_end    = 60;
           page.margin_top    = 60;
           page.margin_bottom = 60;
 
-          // Add the Effect's preferences (if any).
+          // Add the effect's preferences (if any).
-          const preferences = Effect.getPreferences(this);
+          const preferences = effect.getPreferences(this);
           if (preferences) {
             this.gtkBoxAppend(page, preferences);
           }
 
-          stack.add_titled(page, Effect.getNick(), Effect.getLabel());
+          stack.add_titled(page, effect.getNick(), effect.getLabel());
         }
       });
     }
@@ -302,11 +303,11 @@ var PreferencesDialog = class PreferencesDialog {
         const group = Gio.SimpleActionGroup.new();
         window.insert_action_group('open-effects', group);
 
-        ALL_EFFECTS.forEach(Effect => {
+        this._ALL_EFFECTS.forEach(effect => {
-          const [minMajor, minMinor] = Effect.getMinShellVersion();
+          const [minMajor, minMinor] = effect.getMinShellVersion();
           if (utils.shellVersionIsAtLeast(minMajor, minMinor)) {
-            const nick       = Effect.getNick();
+            const nick       = effect.getNick();
-            const label      = Effect.getLabel();
+            const label      = effect.getLabel();
             const actionName = nick + '-open-effect';
             const fullName   = 'open-effects.' + actionName;
 
@@ -324,11 +325,11 @@ var PreferencesDialog = class PreferencesDialog {
         const group = Gio.SimpleActionGroup.new();
         window.insert_action_group('close-effects', group);
 
-        ALL_EFFECTS.forEach(Effect => {
+        this._ALL_EFFECTS.forEach(effect => {
-          const [minMajor, minMinor] = Effect.getMinShellVersion();
+          const [minMajor, minMinor] = effect.getMinShellVersion();
           if (utils.shellVersionIsAtLeast(minMajor, minMinor)) {
-            const nick       = Effect.getNick();
+            const nick       = effect.getNick();
-            const label      = Effect.getLabel();
+            const label      = effect.getLabel();
             const actionName = nick + '-close-effect';
             const fullName   = 'close-effects.' + actionName;
 
@@ -490,17 +491,17 @@ var PreferencesDialog = class PreferencesDialog {
           InternalChildren: ['label', 'button'],
         },
         class BurnMyWindowsEffectPage extends Gtk.Box {  // ------------------------------
-          _init(Effect, dialog) {
+          _init(effect, dialog) {
             super._init();
 
             // Set the effect's name as label.
-            this._label.label = Effect.getLabel();
+            this._label.label = effect.getLabel();
 
             // Open the preview window once the preview button is clicked.
             this._button.connect('clicked', () => {
               // Set the to-be-previewed effect.
-              dialog.getSettings().set_string('open-preview-effect', Effect.getNick());
+              dialog.getSettings().set_string('open-preview-effect', effect.getNick());
-              dialog.getSettings().set_string('close-preview-effect', Effect.getNick());
+              dialog.getSettings().set_string('close-preview-effect', effect.getNick());
 
               // Make sure that the window.show() firther below "sees" this change.
               Gio.Settings.sync();
@@ -508,7 +509,7 @@ var PreferencesDialog = class PreferencesDialog {
               // Create the preview-window.
               const window = new Gtk.Window({
                 // Translators: %s will be replaced by the effect's name.
-                title: _('Preview for %s').replace('%s', Effect.getLabel()),
+                title: _('Preview for %s').replace('%s', effect.getLabel()),
                 default_width: 800,
                 default_height: 450,
                 modal: true,

src/Apparition.js

@@ -13,38 +13,56 @@
 
 '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 hides the actor by violently sucking it into the void of magic.          //
-// towards the middle and then hiding the resulting line from left and right towards    //
-// the center.                                                                          //
 //////////////////////////////////////////////////////////////////////////////////////////
 
-// The shader class for this effect is registered further down in this file. When this
+// The effect class can be used to get some metadata (like the effect's name or supported
-// effect is used for the first time, an instance of this shader class is created. Once
+// GNOME Shell versions), to initialize the respective page of the settings dialog, as
-// the effect is finished, the shader will be stored in the freeShaders array and will
+// well as to create the actual shader for the effect.
-// then be reused if a new shader is requested. ShaderClass which will be used whenever
-// this effect is used.
-let ShaderClass = null;
-let freeShaders = [];
-
-// The effect class is completely static. It 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 Apparition = class Apparition {
 
+  // 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) => {
+      // Store uniform locations of newly created shaders.
+      shader._uSeed       = shader.get_uniform_location('uSeed');
+      shader._uShake      = shader.get_uniform_location('uShake');
+      shader._uTwirl      = shader.get_uniform_location('uTwirl');
+      shader._uSuction    = shader.get_uniform_location('uSuction');
+      shader._uRandomness = shader.get_uniform_location('uRandomness');
+
+      // Write all uniform values at the start of each animation.
+      shader.connect('begin-animation', (shader, settings) => {
+        // 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,       2, [testMode ? 0 : Math.random(), testMode ? 0 : Math.random()]);
+        shader.set_uniform_float(shader._uShake,      1, [settings.get_double('apparition-shake-intensity')]);
+        shader.set_uniform_float(shader._uTwirl,      1, [settings.get_double('apparition-twirl-intensity')]);
+        shader.set_uniform_float(shader._uSuction,    1, [settings.get_double('apparition-suction-intensity')]);
+        shader.set_uniform_float(shader._uRandomness, 1, [settings.get_double('apparition-randomness')]);
+        // clang-format on
+      });
+    });
+  }
+
   // ---------------------------------------------------------------------------- metadata
 
   // The effect is not available on GNOME Shell 3.36 as it requires scaling of the window
   // actor.
-  static getMinShellVersion() {
+  getMinShellVersion() {
     return [3, 38];
   }
 
@@ -52,22 +70,21 @@ var Apparition = class Apparition {
   // 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').
-  static getNick() {
+  getNick() {
     return 'apparition';
   }
 
   // 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.
-  static getLabel() {
+  getLabel() {
     return _('Apparition');
   }
 
   // -------------------------------------------------------------------- API for prefs.js
 
   // This is called by the preferences dialog. It loads the settings page for this effect,
-  // binds all properties to the settings and appends the page to the main stack of the
+  // and binds all properties to the settings.
-  // preferences dialog.
+  getPreferences(dialog) {
-  static getPreferences(dialog) {
 
     // Add the settings page to the builder.
     dialog.getBuilder().add_from_resource(`/ui/${utils.getGTKString()}/Apparition.ui`);
@@ -85,95 +102,10 @@ var Apparition = class Apparition {
 
   // ---------------------------------------------------------------- API for extension.js
 
-  // This is called from extension.js whenever a window is opened or closed with this
-  // effect. It returns an instance of the shader class, trying to reuse previously
-  // created shaders.
-  static getShader(actor, settings, forOpening) {
-    let shader;
-
-    if (freeShaders.length == 0) {
-      shader = new ShaderClass();
-    } else {
-      shader = freeShaders.pop();
-    }
-
-    shader.setUniforms(actor, settings, forOpening);
-
-    return shader;
-  }
-
   // 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+.
-  static getActorScale(settings) {
+  getActorScale(settings) {
     return {x: 2.0, y: 2.0};
   }
-
-  // This is called from extension.js if the extension is disabled. This should free all
-  // static resources.
-  static cleanUp() {
-    freeShaders = [];
-  }
-}
-
-
-//////////////////////////////////////////////////////////////////////////////////////////
-// The shader class for this effect will only be registered in GNOME Shell's process    //
-// (not in the preferences process). It's done this way as Clutter may not be installed //
-// on the system and therefore the preferences would crash.                             //
-//////////////////////////////////////////////////////////////////////////////////////////
-
-if (utils.isInShellProcess()) {
-
-  const Shell = imports.gi.Shell;
-
-  ShaderClass = GObject.registerClass({}, class ShaderClass extends Shell.GLSLEffect {
-    // This is called when the effect is used for the first time. This can be used to
-    // store all required uniform locations.
-    _init() {
-      super._init();
-
-      this._uSeed       = this.get_uniform_location('uSeed');
-      this._uShake      = this.get_uniform_location('uShake');
-      this._uTwirl      = this.get_uniform_location('uTwirl');
-      this._uSuction    = this.get_uniform_location('uSuction');
-      this._uRandomness = this.get_uniform_location('uRandomness');
-    }
-
-    // This is called each time the effect is used. This can be used to retrieve the
-    // configuration from the settings and update all uniforms accordingly.
-    setUniforms(actor, settings, forOpening) {
-      // If we are currently performing integration test, the animation uses a fixed seed.
-      const testMode = settings.get_boolean('test-mode');
-
-      // clang-format off
-      this.set_uniform_float(this._uSeed,       2, [testMode ? 0 : Math.random(), testMode ? 0 : Math.random()]);
-      this.set_uniform_float(this._uShake,      1, [settings.get_double('apparition-shake-intensity')]);
-      this.set_uniform_float(this._uTwirl,      1, [settings.get_double('apparition-twirl-intensity')]);
-      this.set_uniform_float(this._uSuction,    1, [settings.get_double('apparition-suction-intensity')]);
-      this.set_uniform_float(this._uRandomness, 1, [settings.get_double('apparition-randomness')]);
-      // clang-format on
-    }
-
-    // This is called by extension.js when the shader is not used anymore. We will store
-    // this instance of the shader so that it can be re-used in th future.
-    free() {
-      freeShaders.push(this);
-    }
-
-    // This is called by the constructor. This means, it's only called when the effect
-    // is used for the first time.
-    vfunc_build_pipeline() {
-      const code = utils.loadGLSLResource(`/shaders/${Apparition.getNick()}.glsl`);
-
-      // Match anything between the curly brackets of "void main() {...}".
-      const regex = RegExp('void main *\\(\\) *\\{([\\S\\s]+)\\}');
-      const match = regex.exec(code);
-
-      const declarations = code.substr(0, match.index);
-      const main         = match[1];
-
-      this.add_glsl_snippet(Shell.SnippetHook.FRAGMENT, declarations, main, true);
-    }
-  });
 }

src/BrokenGlass.js

@@ -13,41 +13,114 @@
 
 '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 shatters the window into pieces. For an explanation how this works, look //
 // further down in this file into the documentation of the Shader class. This effect is //
 // not available on GNOME 3.3x, due to the limitation described in the documentation    //
 // of vfunc_paint_target further down in this file.                                     //
+// This shader creates a complex-looking effect with rather simple means. Here is how   //
+// it works: The window is drawn five times on top of each other (see the SHARD_LAYERS  //
+// constant in the GLSL code). Each layer only draws some of the shards, all layers     //
+// combined make up the entire window. The layers are then scaled, rotated, and moved   //
+// independently from each other - this creates the impression that all shards are      //
+// moving independently. In reality, there are only five groups of shards! Which shard  //
+// belongs to which layer is defined by the green channel of the texture                //
+// resources/img/shards.png. The red channel of the texture contains the distance to    //
+// the shard edges. This information is used to fade out the shards.                    //
 //////////////////////////////////////////////////////////////////////////////////////////
 
-// The shader class for this effect is registered further down in this file. When this
+// The effect class can be used to get some metadata (like the effect's name or supported
-// effect is used for the first time, an instance of this shader class is created. Once
+// GNOME Shell versions), to initialize the respective page of the settings dialog, as
-// the effect is finished, the shader will be stored in the freeShaders array and will
+// well as to create the actual shader for the effect.
-// then be reused if a new shader is requested. ShaderClass which will be used whenever
-// this effect is used.
-let ShaderClass = null;
-let freeShaders = [];
-
-// This texture will be loaded when the effect is used for the first time.
-let shardTexture = null;
-
-// The effect class is completely static. It 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 BrokenGlass = class BrokenGlass {
 
+  // 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 these modules in this function as they are not available in the
+      // preferences process. This callback is only called within GNOME Shell's process.
+      const {Clutter, GdkPixbuf, Cogl} = imports.gi;
+
+      // Create the texture in the first call.
+      if (!this._shardTexture) {
+        const shardData    = GdkPixbuf.Pixbuf.new_from_resource('/img/shards.png');
+        this._shardTexture = new Clutter.Image();
+        this._shardTexture.set_data(shardData.get_pixels(), Cogl.PixelFormat.RGB_888,
+                                    shardData.width, shardData.height,
+                                    shardData.rowstride);
+      }
+
+      // Store all uniform locations.
+      shader._uShardTexture = shader.get_uniform_location('uShardTexture');
+      shader._uSeed         = shader.get_uniform_location('uSeed');
+      shader._uEpicenter    = shader.get_uniform_location('uEpicenter');
+      shader._uShardScale   = shader.get_uniform_location('uShardScale');
+      shader._uBlowForce    = shader.get_uniform_location('uBlowForce');
+      shader._uGravity      = shader.get_uniform_location('uGravity');
+
+      // And update all uniforms at the start of each animation.
+      shader.connect('begin-animation', (shader, settings, forOpening, actor) => {
+        // Usually, the shards fly away from the center of the window.
+        let epicenterX = 0.5;
+        let epicenterY = 0.5;
+
+        // However, if this option is set, we use the mouse pointer position.
+        if (!forOpening && settings.get_boolean('broken-glass-use-pointer')) {
+          const [x, y]               = global.get_pointer();
+          const [ok, localX, localY] = actor.transform_stage_point(x, y);
+
+          if (ok) {
+            epicenterX = localX / actor.width;
+            epicenterY = localY / actor.height;
+          }
+        }
+
+        // If we are currently performing integration test, the animation uses a fixed
+        // seed.
+        const testMode = settings.get_boolean('test-mode');
+
+        // clang-format off
+        shader.set_uniform_float(shader._uSeed,       2, [testMode ? 0 : Math.random(), testMode ? 0 : Math.random()]);
+        shader.set_uniform_float(shader._uEpicenter,  2, [epicenterX, epicenterY]);
+        shader.set_uniform_float(shader._uShardScale, 1, [settings.get_double('broken-glass-scale')]);
+        shader.set_uniform_float(shader._uBlowForce,  1, [settings.get_double('broken-glass-blow-force')]);
+        shader.set_uniform_float(shader._uGravity,    1, [settings.get_double('broken-glass-gravity')]);
+        // clang-format on
+      });
+
+      // This is required to bind the shard texture for drawing. Sadly, this seems to be
+      // impossible under GNOME 3.3x as this.get_pipeline() is not available. It was
+      // called get_target() back then but this is not wrapped in GJS.
+      // https://gitlab.gnome.org/GNOME/mutter/-/blob/gnome-3-36/clutter/clutter/clutter-offscreen-effect.c#L598
+      shader.connect('update-animation', (shader) => {
+        const pipeline = shader.get_pipeline();
+
+        // Use linear filtering for the window texture.
+        pipeline.set_layer_filters(0, Cogl.PipelineFilter.LINEAR,
+                                   Cogl.PipelineFilter.LINEAR);
+
+        // Bind the shard texture.
+        pipeline.set_layer_texture(1, this._shardTexture.get_texture());
+        pipeline.set_layer_wrap_mode(1, Cogl.PipelineWrapMode.REPEAT);
+        pipeline.set_uniform_1i(shader._uShardTexture, 1);
+      });
+    });
+  }
+
   // ---------------------------------------------------------------------------- metadata
 
   // This effect is only available on GNOME Shell 40+.
-  static getMinShellVersion() {
+  getMinShellVersion() {
     return [40, 0];
   }
 
@@ -55,22 +128,21 @@ var BrokenGlass = class BrokenGlass {
   // 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').
-  static getNick() {
+  getNick() {
     return 'broken-glass';
   }
 
   // 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.
-  static getLabel() {
+  getLabel() {
     return _('Broken Glass');
   }
 
   // -------------------------------------------------------------------- API for prefs.js
 
   // This is called by the preferences dialog. It loads the settings page for this effect,
-  // binds all properties to the settings and appends the page to the main stack of the
+  // and binds all properties to the settings.
-  // preferences dialog.
+  getPreferences(dialog) {
-  static getPreferences(dialog) {
 
     // Add the settings page to the builder.
     dialog.getBuilder().add_from_resource('/ui/gtk4/BrokenGlass.ui');
@@ -88,148 +160,10 @@ var BrokenGlass = class BrokenGlass {
 
   // ---------------------------------------------------------------- API for extension.js
 
-  // This is called from extension.js whenever a window is opened or closed with this
-  // effect. It returns an instance of the shader class, trying to reuse previously
-  // created shaders.
-  static getShader(actor, settings, forOpening) {
-    let shader;
-
-    if (freeShaders.length == 0) {
-      shader = new ShaderClass();
-    } else {
-      shader = freeShaders.pop();
-    }
-
-    shader.setUniforms(actor, settings, forOpening);
-
-    return shader;
-  }
-
   // 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+.
-  static getActorScale(settings) {
+  getActorScale(settings) {
     return {x: 2.0, y: 2.0};
   }
-
-  // This is called from extension.js if the extension is disabled. This should free all
-  // static resources.
-  static cleanUp() {
-    freeShaders  = [];
-    shardTexture = null;
-  }
-}
-
-
-//////////////////////////////////////////////////////////////////////////////////////////
-// The shader class for this effect will only be registered in GNOME Shell's process    //
-// (not in the preferences process). It's done this way as Clutter may not be installed //
-// on the system and therefore the preferences would crash.                             //
-//////////////////////////////////////////////////////////////////////////////////////////
-
-if (utils.isInShellProcess()) {
-
-  const {Clutter, GdkPixbuf, Cogl, Shell} = imports.gi;
-
-  // This shader creates a complex-looking effect with rather simple means. Here is how it
-  // works: The window is drawn five times on top of each other (see the SHARD_LAYERS
-  // constant in the GLSL code). Each layer only draws some of the shards, all layers
-  // combined make up the entire window. The layers are then scaled, rotated, and moved
-  // independently from each other - this creates the impression that all shards are
-  // moving independently. In reality, there are only five groups of shards! Which shard
-  // belongs to which layer is defined by the green channel of the texture
-  // resources/img/shards.png. The red channel of the texture contains the distance to the
-  // shard edges. This information is used to fade out the shards.
-  ShaderClass = GObject.registerClass({}, class ShaderClass extends Shell.GLSLEffect {
-    // This is called when the effect is used for the first time. This can be used to
-    // store all required uniform locations.
-    _init() {
-      super._init();
-
-      // Load the shards texture.
-      if (shardTexture == null) {
-        const shardData = GdkPixbuf.Pixbuf.new_from_resource('/img/shards.png');
-        shardTexture    = new Clutter.Image();
-        shardTexture.set_data(shardData.get_pixels(), Cogl.PixelFormat.RGB_888,
-                              shardData.width, shardData.height, shardData.rowstride);
-      }
-
-      this._uShardTexture = this.get_uniform_location('uShardTexture');
-      this._uSeed         = this.get_uniform_location('uSeed');
-      this._uEpicenter    = this.get_uniform_location('uEpicenter');
-      this._uShardScale   = this.get_uniform_location('uShardScale');
-      this._uBlowForce    = this.get_uniform_location('uBlowForce');
-      this._uGravity      = this.get_uniform_location('uGravity');
-    }
-
-    // This is called each time the effect is used. This can be used to retrieve the
-    // configuration from the settings and update all uniforms accordingly.
-    setUniforms(actor, settings, forOpening) {
-      // Usually, the shards fly away from the center of the window.
-      let epicenterX = 0.5;
-      let epicenterY = 0.5;
-
-      // However, if this option is set, we use the mouse pointer position.
-      if (!forOpening && settings.get_boolean('broken-glass-use-pointer')) {
-        const [x, y]               = global.get_pointer();
-        const [ok, localX, localY] = actor.transform_stage_point(x, y);
-
-        if (ok) {
-          epicenterX = localX / actor.width;
-          epicenterY = localY / actor.height;
-        }
-      }
-
-      // If we are currently performing integration test, the animation uses a fixed seed.
-      const testMode = settings.get_boolean('test-mode');
-
-      // clang-format off
-      this.set_uniform_float(this._uSeed,       2, [testMode ? 0 : Math.random(), testMode ? 0 : Math.random()]);
-      this.set_uniform_float(this._uEpicenter,  2, [epicenterX, epicenterY]);
-      this.set_uniform_float(this._uShardScale, 1, [settings.get_double('broken-glass-scale')]);
-      this.set_uniform_float(this._uBlowForce,  1, [settings.get_double('broken-glass-blow-force')]);
-      this.set_uniform_float(this._uGravity,    1, [settings.get_double('broken-glass-gravity')]);
-      // clang-format on
-    }
-
-    // This is called by extension.js when the shader is not used anymore. We will store
-    // this instance of the shader so that it can be re-used in th future.
-    free() {
-      freeShaders.push(this);
-    }
-
-    // This is called by the constructor. This means, it's only called when the effect
-    // is used for the first time.
-    vfunc_build_pipeline() {
-      const code = utils.loadGLSLResource(`/shaders/${BrokenGlass.getNick()}.glsl`);
-
-      // Match anything between the curly brackets of "void main() {...}".
-      const regex = RegExp('void main *\\(\\) *\\{([\\S\\s]+)\\}');
-      const match = regex.exec(code);
-
-      const declarations = code.substr(0, match.index);
-      const main         = match[1];
-
-      this.add_glsl_snippet(Shell.SnippetHook.FRAGMENT, declarations, main, true);
-    }
-
-    // This is overridden to bind the shard texture for drawing. Sadly, this seems to be
-    // impossible under GNOME 3.3x as this.get_pipeline() is not available. It was called
-    // get_target() back then but this is not wrapped in GJS.
-    // https://gitlab.gnome.org/GNOME/mutter/-/blob/gnome-3-36/clutter/clutter/clutter-offscreen-effect.c#L598
-    vfunc_paint_target(node, paint_context) {
-      const pipeline = this.get_pipeline();
-
-      // Use linear filtering for the window texture.
-      pipeline.set_layer_filters(0, Cogl.PipelineFilter.LINEAR,
-                                 Cogl.PipelineFilter.LINEAR);
-
-      // Bind the shard texture.
-      pipeline.set_layer_texture(1, shardTexture.get_texture());
-      pipeline.set_layer_wrap_mode(1, Cogl.PipelineWrapMode.REPEAT);
-      pipeline.set_uniform_1i(this._uShardTexture, 1);
-
-      super.vfunc_paint_target(node, paint_context);
-    }
-  });
 }

src/EnergizeA.js

@@ -20,28 +20,48 @@ 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 looks a bit like the transporter effect from TOS.                        //
 //////////////////////////////////////////////////////////////////////////////////////////
 
-// The shader class for this effect is registered further down in this file. When this
+// The effect class can be used to get some metadata (like the effect's name or supported
-// effect is used for the first time, an instance of this shader class is created. Once
+// GNOME Shell versions), to initialize the respective page of the settings dialog, as
-// the effect is finished, the shader will be stored in the freeShaders array and will
+// well as to create the actual shader for the effect.
-// then be reused if a new shader is requested. ShaderClass which will be used whenever
-// this effect is used.
-let ShaderClass = null;
-let freeShaders = [];
-
-// The effect class is completely static. It 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 EnergizeA = class EnergizeA {
 
+  // 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._uColor = shader.get_uniform_location('uColor');
+      shader._uScale = shader.get_uniform_location('uScale');
+
+      // 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('energize-a-color'))[1];
+
+        // clang-format off
+        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('energize-a-scale')]);
+        // clang-format on
+      });
+    });
+  }
+
   // ---------------------------------------------------------------------------- metadata
 
   // The effect is available on all GNOME Shell versions supported by this extension.
-  static getMinShellVersion() {
+  getMinShellVersion() {
     return [3, 36];
   }
 
@@ -49,22 +69,21 @@ var EnergizeA = class EnergizeA {
   // 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').
-  static getNick() {
+  getNick() {
     return 'energize-a';
   }
 
   // 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.
-  static getLabel() {
+  getLabel() {
     return _('Energize A');
   }
 
   // -------------------------------------------------------------------- API for prefs.js
 
   // This is called by the preferences dialog. It loads the settings page for this effect,
-  // binds all properties to the settings and appends the page to the main stack of the
+  // and binds all properties to the settings.
-  // preferences dialog.
+  getPreferences(dialog) {
-  static getPreferences(dialog) {
 
     // Add the settings page to the builder.
     dialog.getBuilder().add_from_resource(`/ui/${utils.getGTKString()}/EnergizeA.ui`);
@@ -80,88 +99,10 @@ var EnergizeA = class EnergizeA {
 
   // ---------------------------------------------------------------- API for extension.js
 
-  // This is called from extension.js whenever a window is opened or closed with this
-  // effect. It returns an instance of the shader class, trying to reuse previously
-  // created shaders.
-  static getShader(actor, settings, forOpening) {
-    let shader;
-
-    if (freeShaders.length == 0) {
-      shader = new ShaderClass();
-    } else {
-      shader = freeShaders.pop();
-    }
-
-    shader.setUniforms(actor, settings, forOpening);
-
-    return shader;
-  }
-
   // 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+.
-  static getActorScale(settings) {
+  getActorScale(settings) {
     return {x: 1.0, y: 1.0};
   }
-
-  // This is called from extension.js if the extension is disabled. This should free all
-  // static resources.
-  static cleanUp() {
-    freeShaders = [];
-  }
-}
-
-
-//////////////////////////////////////////////////////////////////////////////////////////
-// The shader class for this effect will only be registered in GNOME Shell's process    //
-// (not in the preferences process). It's done this way as Clutter may not be installed //
-// on the system and therefore the preferences would crash.                             //
-//////////////////////////////////////////////////////////////////////////////////////////
-
-if (utils.isInShellProcess()) {
-
-  const {Clutter, Shell} = imports.gi;
-
-  ShaderClass = GObject.registerClass({}, class ShaderClass extends Shell.GLSLEffect {
-    // This is called when the effect is used for the first time. This can be used to
-    // store all required uniform locations.
-    _init() {
-      super._init();
-
-      this._uColor = this.get_uniform_location('uColor');
-      this._uScale = this.get_uniform_location('uScale');
-    }
-
-    // This is called each time the effect is used. This can be used to retrieve the
-    // configuration from the settings and update all uniforms accordingly.
-    setUniforms(actor, settings, forOpening) {
-      const c = Clutter.Color.from_string(settings.get_string('energize-a-color'))[1];
-
-      // clang-format off
-      this.set_uniform_float(this._uColor, 3, [c.red / 255, c.green / 255, c.blue / 255]);
-      this.set_uniform_float(this._uScale, 1, [settings.get_double('energize-a-scale')]);
-      // clang-format on
-    }
-
-    // This is called by extension.js when the shader is not used anymore. We will store
-    // this instance of the shader so that it can be re-used in th future.
-    free() {
-      freeShaders.push(this);
-    }
-
-    // This is called by the constructor. This means, it's only called when the effect
-    // is used for the first time.
-    vfunc_build_pipeline() {
-      const code = utils.loadGLSLResource(`/shaders/${EnergizeA.getNick()}.glsl`);
-
-      // Match anything between the curly brackets of "void main() {...}".
-      const regex = RegExp('void main *\\(\\) *\\{([\\S\\s]+)\\}');
-      const match = regex.exec(code);
-
-      const declarations = code.substr(0, match.index);
-      const main         = match[1];
-
-      this.add_glsl_snippet(Shell.SnippetHook.FRAGMENT, declarations, main, true);
-    }
-  });
 }

src/EnergizeB.js

@@ -20,28 +20,49 @@ 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 looks a bit like the transporter effect from TNG.                        //
 //////////////////////////////////////////////////////////////////////////////////////////
 
-// The shader class for this effect is registered further down in this file. When this
+// The effect class can be used to get some metadata (like the effect's name or supported
-// effect is used for the first time, an instance of this shader class is created. Once
+// GNOME Shell versions), to initialize the respective page of the settings dialog, as
-// the effect is finished, the shader will be stored in the freeShaders array and will
+// well as to create the actual shader for the effect.
-// then be reused if a new shader is requested. ShaderClass which will be used whenever
-// this effect is used.
-let ShaderClass = null;
-let freeShaders = [];
-
-// The effect class is completely static. It 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 EnergizeB = class EnergizeB {
 
+  // 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._uColor = shader.get_uniform_location('uColor');
+      shader._uScale = shader.get_uniform_location('uScale');
+
+      // 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('energize-b-color'))[1];
+
+        // clang-format off
+        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('energize-b-scale')]);
+        // clang-format on
+      });
+    });
+  }
+
+
   // ---------------------------------------------------------------------------- metadata
 
   // The effect is available on all GNOME Shell versions supported by this extension.
-  static getMinShellVersion() {
+  getMinShellVersion() {
     return [3, 36];
   }
 
@@ -49,22 +70,21 @@ var EnergizeB = class EnergizeB {
   // 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').
-  static getNick() {
+  getNick() {
     return 'energize-b';
   }
 
   // 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.
-  static getLabel() {
+  getLabel() {
     return _('Energize B');
   }
 
   // -------------------------------------------------------------------- API for prefs.js
 
   // This is called by the preferences dialog. It loads the settings page for this effect,
-  // binds all properties to the settings and appends the page to the main stack of the
+  // and binds all properties to the settings.
-  // preferences dialog.
+  getPreferences(dialog) {
-  static getPreferences(dialog) {
 
     // Add the settings page to the builder.
     dialog.getBuilder().add_from_resource(`/ui/${utils.getGTKString()}/EnergizeB.ui`);
@@ -80,88 +100,10 @@ var EnergizeB = class EnergizeB {
 
   // ---------------------------------------------------------------- API for extension.js
 
-  // This is called from extension.js whenever a window is opened or closed with this
-  // effect. It returns an instance of the shader class, trying to reuse previously
-  // created shaders.
-  static getShader(actor, settings, forOpening) {
-    let shader;
-
-    if (freeShaders.length == 0) {
-      shader = new ShaderClass();
-    } else {
-      shader = freeShaders.pop();
-    }
-
-    shader.setUniforms(actor, settings, forOpening);
-
-    return shader;
-  }
-
   // 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+.
-  static getActorScale(settings) {
+  getActorScale(settings) {
     return {x: 1.0, y: 1.0};
   }
-
-  // This is called from extension.js if the extension is disabled. This should free all
-  // static resources.
-  static cleanUp() {
-    freeShaders = [];
-  }
-}
-
-
-//////////////////////////////////////////////////////////////////////////////////////////
-// The shader class for this effect will only be registered in GNOME Shell's process    //
-// (not in the preferences process). It's done this way as Clutter may not be installed //
-// on the system and therefore the preferences would crash.                             //
-//////////////////////////////////////////////////////////////////////////////////////////
-
-if (utils.isInShellProcess()) {
-
-  const {Clutter, Shell} = imports.gi;
-
-  ShaderClass = GObject.registerClass({}, class ShaderClass extends Shell.GLSLEffect {
-    // This is called when the effect is used for the first time. This can be used to
-    // store all required uniform locations.
-    _init() {
-      super._init();
-
-      this._uColor = this.get_uniform_location('uColor');
-      this._uScale = this.get_uniform_location('uScale');
-    }
-
-    // This is called each time the effect is used. This can be used to retrieve the
-    // configuration from the settings and update all uniforms accordingly.
-    setUniforms(actor, settings, forOpening) {
-      const c = Clutter.Color.from_string(settings.get_string('energize-b-color'))[1];
-
-      // clang-format off
-      this.set_uniform_float(this._uColor, 3, [c.red / 255, c.green / 255, c.blue / 255]);
-      this.set_uniform_float(this._uScale, 1, [settings.get_double('energize-b-scale')]);
-      // clang-format on
-    }
-
-    // This is called by extension.js when the shader is not used anymore. We will store
-    // this instance of the shader so that it can be re-used in th future.
-    free() {
-      freeShaders.push(this);
-    }
-
-    // This is called by the constructor. This means, it's only called when the effect
-    // is used for the first time.
-    vfunc_build_pipeline() {
-      const code = utils.loadGLSLResource(`/shaders/${EnergizeB.getNick()}.glsl`);
-
-      // Match anything between the curly brackets of "void main() {...}".
-      const regex = RegExp('void main *\\(\\) *\\{([\\S\\s]+)\\}');
-      const match = regex.exec(code);
-
-      const declarations = code.substr(0, match.index);
-      const main         = match[1];
-
-      this.add_glsl_snippet(Shell.SnippetHook.FRAGMENT, declarations, main, true);
-    }
-  });
 }

src/Fire.js

@@ -13,13 +13,14 @@
 
 'use strict';
 
-const {Gio, GObject} = imports.gi;
+const {Gio} = imports.gi;
 
 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 is a homage to the good old Compiz days. However, it is implemented      //
@@ -29,23 +30,58 @@ const utils          = Me.imports.src.utils;
 // there are a couple of moving gradients which fade-in or fade-out the fire effect.    //
 //////////////////////////////////////////////////////////////////////////////////////////
 
-// The shader class for this effect is registered further down in this file. When this
+// The effect class can be used to get some metadata (like the effect's name or supported
-// effect is used for the first time, an instance of this shader class is created. Once
+// GNOME Shell versions), to initialize the respective page of the settings dialog, as
-// the effect is finished, the shader will be stored in the freeShaders array and will
+// well as to create the actual shader for the effect.
-// then be reused if a new shader is requested. ShaderClass which will be used whenever
-// this effect is used.
-let ShaderClass = null;
-let freeShaders = [];
-
-// The effect class is completely static. It 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 Fire = class Fire {
 
+
+  // 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 all uniform locations.
+      shader._uGradient = [
+        shader.get_uniform_location('uGradient1'),
+        shader.get_uniform_location('uGradient2'),
+        shader.get_uniform_location('uGradient3'),
+        shader.get_uniform_location('uGradient4'),
+        shader.get_uniform_location('uGradient5'),
+      ];
+
+      shader._u3DNoise       = shader.get_uniform_location('u3DNoise');
+      shader._uScale         = shader.get_uniform_location('uScale');
+      shader._uMovementSpeed = shader.get_uniform_location('uMovementSpeed');
+
+      // And update all uniforms at the start of each animation.
+      shader.connect('begin-animation', (shader, settings) => {
+        for (let i = 1; i <= 5; i++) {
+          const c = Clutter.Color.from_string(settings.get_string('fire-color-' + i))[1];
+          shader.set_uniform_float(
+            shader._uGradient[i - 1], 4,
+            [c.red / 255, c.green / 255, c.blue / 255, c.alpha / 255]);
+        }
+
+        // clang-format off
+        shader.set_uniform_float(shader._u3DNoise,       1, [settings.get_boolean('flame-3d-noise')]);
+        shader.set_uniform_float(shader._uScale,         1, [settings.get_double('flame-scale')]);
+        shader.set_uniform_float(shader._uMovementSpeed, 1, [settings.get_double('flame-movement-speed')]);
+        // clang-format on
+      });
+    });
+  }
+
   // ---------------------------------------------------------------------------- metadata
 
   // The effect is available on all GNOME Shell versions supported by this extension.
-  static getMinShellVersion() {
+  getMinShellVersion() {
     return [3, 36];
   }
 
@@ -53,22 +89,21 @@ var Fire = class Fire {
   // 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').
-  static getNick() {
+  getNick() {
     return 'fire';
   }
 
   // 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.
-  static getLabel() {
+  getLabel() {
     return _('Fire');
   }
 
   // -------------------------------------------------------------------- API for prefs.js
 
   // This is called by the preferences dialog. It loads the settings page for this effect,
-  // binds all properties to the settings and appends the page to the main stack of the
+  // and binds all properties to the settings.
-  // preferences dialog.
+  getPreferences(dialog) {
-  static getPreferences(dialog) {
 
     // Add the settings page to the builder.
     dialog.getBuilder().add_from_resource(`/ui/${utils.getGTKString()}/Fire.ui`);
@@ -94,7 +129,7 @@ var Fire = class Fire {
     });
 
     // Initialize the fire-preset dropdown.
-    Fire._createFirePresets(dialog);
+    this._createFirePresets(dialog);
 
     // Finally, return the new settings page.
     return dialog.getBuilder().get_object('fire-prefs');
@@ -102,40 +137,17 @@ var Fire = class Fire {
 
   // ---------------------------------------------------------------- API for extension.js
 
-  // This is called from extension.js whenever a window is opened or closed with this
-  // effect. It returns an instance of the shader class, trying to reuse previously
-  // created shaders.
-  static getShader(actor, settings, forOpening) {
-    let shader;
-
-    if (freeShaders.length == 0) {
-      shader = new ShaderClass();
-    } else {
-      shader = freeShaders.pop();
-    }
-
-    shader.setUniforms(actor, settings, forOpening);
-
-    return shader;
-  }
-
   // 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+.
-  static getActorScale(settings) {
+  getActorScale(settings) {
     return {x: 1.0, y: 1.0};
   }
 
-  // This is called from extension.js if the extension is disabled. This should free all
-  // static resources.
-  static cleanUp() {
-    freeShaders = [];
-  }
-
   // ----------------------------------------------------------------------- private stuff
 
   // This populates the preset dropdown menu for the fire options.
-  static _createFirePresets(dialog) {
+  _createFirePresets(dialog) {
     dialog.getBuilder().get_object('fire-prefs').connect('realize', (widget) => {
       const presets = [
         {
@@ -221,74 +233,3 @@ var Fire = class Fire {
     });
   }
 }
-
-
-//////////////////////////////////////////////////////////////////////////////////////////
-// The shader class for this effect will only be registered in GNOME Shell's process    //
-// (not in the preferences process). It's done this way as Clutter may not be installed //
-// on the system and therefore the preferences would crash.                             //
-//////////////////////////////////////////////////////////////////////////////////////////
-
-if (utils.isInShellProcess()) {
-
-  const {Clutter, Shell} = imports.gi;
-
-  ShaderClass = GObject.registerClass({}, class ShaderClass extends Shell.GLSLEffect {
-    // This is called when the effect is used for the first time. This can be used to
-    // store all required uniform locations.
-    _init() {
-      super._init();
-
-      this._uGradient = [
-        this.get_uniform_location('uGradient1'),
-        this.get_uniform_location('uGradient2'),
-        this.get_uniform_location('uGradient3'),
-        this.get_uniform_location('uGradient4'),
-        this.get_uniform_location('uGradient5'),
-      ];
-
-      this._u3DNoise       = this.get_uniform_location('u3DNoise');
-      this._uScale         = this.get_uniform_location('uScale');
-      this._uMovementSpeed = this.get_uniform_location('uMovementSpeed');
-    }
-
-    // This is called each time the effect is used. This can be used to retrieve the
-    // configuration from the settings and update all uniforms accordingly.
-    setUniforms(actor, settings, forOpening) {
-
-      // Load the gradient values from the settings.
-      for (let i = 1; i <= 5; i++) {
-        const c = Clutter.Color.from_string(settings.get_string('fire-color-' + i))[1];
-        this.set_uniform_float(this._uGradient[i - 1], 4,
-                               [c.red / 255, c.green / 255, c.blue / 255, c.alpha / 255]);
-      }
-
-      // clang-format off
-      this.set_uniform_float(this._u3DNoise,       1, [settings.get_boolean('flame-3d-noise')]);
-      this.set_uniform_float(this._uScale,         1, [settings.get_double('flame-scale')]);
-      this.set_uniform_float(this._uMovementSpeed, 1, [settings.get_double('flame-movement-speed')]);
-      // clang-format on
-    }
-
-    // This is called by extension.js when the shader is not used anymore. We will store
-    // this instance of the shader so that it can be re-used in th future.
-    free() {
-      freeShaders.push(this);
-    }
-
-    // This is called by the constructor. This means, it's only called when the effect
-    // is used for the first time.
-    vfunc_build_pipeline() {
-      const code = utils.loadGLSLResource(`/shaders/${Fire.getNick()}.glsl`);
-
-      // Match anything between the curly brackets of "void main() {...}".
-      const regex = RegExp('void main *\\(\\) *\\{([\\S\\s]+)\\}');
-      const match = regex.exec(code);
-
-      const declarations = code.substr(0, match.index);
-      const main         = match[1];
-
-      this.add_glsl_snippet(Shell.SnippetHook.FRAGMENT, declarations, main, true);
-    }
-  });
-}

src/Hexagon.js

@@ -20,29 +20,66 @@ 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 overlays a glowing hexagonal grid over the window. The grid cells then   //
 // gradually shrink until the window is fully dissolved.                                //
 //////////////////////////////////////////////////////////////////////////////////////////
 
-// The shader class for this effect is registered further down in this file. When this
+// The effect class can be used to get some metadata (like the effect's name or supported
-// effect is used for the first time, an instance of this shader class is created. Once
+// GNOME Shell versions), to initialize the respective page of the settings dialog, as
-// the effect is finished, the shader will be stored in the freeShaders array and will
+// well as to create the actual shader for the effect.
-// then be reused if a new shader is requested. ShaderClass which will be used whenever
-// this effect is used.
-let ShaderClass = null;
-let freeShaders = [];
-
-// The effect class is completely static. It 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 Hexagon = class Hexagon {
 
+  // 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._uAdditiveBlending = shader.get_uniform_location('uAdditiveBlending');
+      shader._uSeed             = shader.get_uniform_location('uSeed');
+      shader._uScale            = shader.get_uniform_location('uScale');
+      shader._uLineWidth        = shader.get_uniform_location('uLineWidth');
+      shader._uGlowColor        = shader.get_uniform_location('uGlowColor');
+      shader._uLineColor        = shader.get_uniform_location('uLineColor');
+
+      // Write all uniform values at the start of each animation.
+      shader.connect('begin-animation', (shader, settings) => {
+        // Get the two configurable colors. They are directly injected into the shader
+        // code below.
+        const gc =
+          Clutter.Color.from_string(settings.get_string('hexagon-glow-color'))[1];
+        const lc =
+          Clutter.Color.from_string(settings.get_string('hexagon-line-color'))[1];
+
+        // If we are currently performing integration test, the animation uses a fixed
+        // seed.
+        const testMode = settings.get_boolean('test-mode');
+
+        // clang-format off
+        shader.set_uniform_float(shader._uAdditiveBlending, 1, [settings.get_boolean('hexagon-additive-blending')]);
+        shader.set_uniform_float(shader._uSeed,             2, [testMode ? 0 : Math.random(), testMode ? 0 : Math.random()]);
+        shader.set_uniform_float(shader._uScale,            1, [settings.get_double('hexagon-scale')]);
+        shader.set_uniform_float(shader._uLineWidth,        1, [settings.get_double('hexagon-line-width')]);
+        shader.set_uniform_float(shader._uGlowColor,        4, [gc.red / 255, gc.green / 255, gc.blue / 255, gc.alpha / 255]);
+        shader.set_uniform_float(shader._uLineColor,        4, [lc.red / 255, lc.green / 255, lc.blue / 255, lc.alpha / 255]);
+        // clang-format on
+      });
+    });
+  }
+
   // ---------------------------------------------------------------------------- metadata
 
   // The effect is available on all GNOME Shell versions supported by this extension.
-  static getMinShellVersion() {
+  getMinShellVersion() {
     return [3, 36];
   }
 
@@ -50,22 +87,21 @@ var Hexagon = class Hexagon {
   // 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').
-  static getNick() {
+  getNick() {
     return 'hexagon';
   }
 
   // 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.
-  static getLabel() {
+  getLabel() {
     return _('Hexagon');
   }
 
   // -------------------------------------------------------------------- API for prefs.js
 
   // This is called by the preferences dialog. It loads the settings page for this effect,
-  // binds all properties to the settings and appends the page to the main stack of the
+  // and binds all properties to the settings.
-  // preferences dialog.
+  getPreferences(dialog) {
-  static getPreferences(dialog) {
 
     // Add the settings page to the builder.
     dialog.getBuilder().add_from_resource(`/ui/${utils.getGTKString()}/Hexagon.ui`);
@@ -84,103 +120,10 @@ var Hexagon = class Hexagon {
 
   // ---------------------------------------------------------------- API for extension.js
 
-  // This is called from extension.js whenever a window is opened or closed with this
-  // effect. It returns an instance of the shader class, trying to reuse previously
-  // created shaders.
-  static getShader(actor, settings, forOpening) {
-    let shader;
-
-    if (freeShaders.length == 0) {
-      shader = new ShaderClass();
-    } else {
-      shader = freeShaders.pop();
-    }
-
-    shader.setUniforms(actor, settings, forOpening);
-
-    return shader;
-  }
-
   // 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+.
-  static getActorScale(settings) {
+  getActorScale(settings) {
     return {x: 1.0, y: 1.0};
   }
-
-  // This is called from extension.js if the extension is disabled. This should free all
-  // static resources.
-  static cleanUp() {
-    freeShaders = [];
-  }
-}
-
-
-//////////////////////////////////////////////////////////////////////////////////////////
-// The shader class for this effect will only be registered in GNOME Shell's process    //
-// (not in the preferences process). It's done this way as Clutter may not be installed //
-// on the system and therefore the preferences would crash.                             //
-//////////////////////////////////////////////////////////////////////////////////////////
-
-if (utils.isInShellProcess()) {
-
-  const {Clutter, Shell} = imports.gi;
-
-  ShaderClass = GObject.registerClass({}, class ShaderClass extends Shell.GLSLEffect {
-    // This is called when the effect is used for the first time. This can be used to
-    // store all required uniform locations.
-    _init() {
-      super._init();
-
-      this._uAdditiveBlending = this.get_uniform_location('uAdditiveBlending');
-      this._uSeed             = this.get_uniform_location('uSeed');
-      this._uScale            = this.get_uniform_location('uScale');
-      this._uLineWidth        = this.get_uniform_location('uLineWidth');
-      this._uGlowColor        = this.get_uniform_location('uGlowColor');
-      this._uLineColor        = this.get_uniform_location('uLineColor');
-    }
-
-    // This is called each time the effect is used. This can be used to retrieve the
-    // configuration from the settings and update all uniforms accordingly.
-    setUniforms(actor, settings, forOpening) {
-
-      // Get the two configurable colors. They are directly injected into the shader code
-      // below.
-      const gc = Clutter.Color.from_string(settings.get_string('hexagon-glow-color'))[1];
-      const lc = Clutter.Color.from_string(settings.get_string('hexagon-line-color'))[1];
-
-      // If we are currently performing integration test, the animation uses a fixed seed.
-      const testMode = settings.get_boolean('test-mode');
-
-      // clang-format off
-      this.set_uniform_float(this._uAdditiveBlending, 1, [settings.get_boolean('hexagon-additive-blending')]);
-      this.set_uniform_float(this._uSeed,             2, [testMode ? 0 : Math.random(), testMode ? 0 : Math.random()]);
-      this.set_uniform_float(this._uScale,            1, [settings.get_double('hexagon-scale')]);
-      this.set_uniform_float(this._uLineWidth,        1, [settings.get_double('hexagon-line-width')]);
-      this.set_uniform_float(this._uGlowColor,        4, [gc.red / 255, gc.green / 255, gc.blue / 255, gc.alpha / 255]);
-      this.set_uniform_float(this._uLineColor,        4, [lc.red / 255, lc.green / 255, lc.blue / 255, lc.alpha / 255]);
-      // clang-format on
-    }
-
-    // This is called by extension.js when the shader is not used anymore. We will store
-    // this instance of the shader so that it can be re-used in th future.
-    free() {
-      freeShaders.push(this);
-    }
-
-    // This is called by the constructor. This means, it's only called when the effect
-    // is used for the first time.
-    vfunc_build_pipeline() {
-      const code = utils.loadGLSLResource(`/shaders/${Hexagon.getNick()}.glsl`);
-
-      // Match anything between the curly brackets of "void main() {...}".
-      const regex = RegExp('void main *\\(\\) *\\{([\\S\\s]+)\\}');
-      const match = regex.exec(code);
-
-      const declarations = code.substr(0, match.index);
-      const main         = match[1];
-
-      this.add_glsl_snippet(Shell.SnippetHook.FRAGMENT, declarations, main, true);
-    }
-  });
 }

src/Matrix.js

@@ -20,6 +20,7 @@ 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;
 
 //////////////////////////////////////////////////////////////////////////////////////////
 // The Matrix shader multiplies a grid of random letters with some gradients which are  //
@@ -29,26 +30,72 @@ const utils          = Me.imports.src.utils;
 // documentation of vfunc_paint_target further down in this file.                       //
 //////////////////////////////////////////////////////////////////////////////////////////
 
-// The shader class for this effect is registered further down in this file. When this
+// The effect class can be used to get some metadata (like the effect's name or supported
-// effect is used for the first time, an instance of this shader class is created. Once
+// GNOME Shell versions), to initialize the respective page of the settings dialog, as
-// the effect is finished, the shader will be stored in the freeShaders array and will
+// well as to create the actual shader for the effect.
-// then be reused if a new shader is requested. ShaderClass which will be used whenever
-// this effect is used.
-let ShaderClass = null;
-let freeShaders = [];
-
-// This texture will be loaded when the effect is used for the first time.
-let fontTexture = null;
-
-// The effect class is completely static. It 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 Matrix = class Matrix {
 
+  // 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 these modules in this function as they are not available in the
+      // preferences process. This callback is only called within GNOME Shell's process.
+      const {Clutter, GdkPixbuf, Cogl} = imports.gi;
+
+      // Create the texture in the first call.
+      if (!this._fontTexture) {
+        const fontData    = GdkPixbuf.Pixbuf.new_from_resource('/img/matrixFont.png');
+        this._fontTexture = new Clutter.Image();
+        this._fontTexture.set_data(
+          fontData.get_pixels(),
+          fontData.has_alpha ? Cogl.PixelFormat.RGBA_8888 : Cogl.PixelFormat.RGB_888,
+          fontData.width, fontData.height, fontData.rowstride);
+      }
+
+      // Store uniform locations of newly created shaders.
+      shader._uFontTexture = shader.get_uniform_location('uFontTexture');
+      shader._uTrailColor  = shader.get_uniform_location('uTrailColor');
+      shader._uTipColor    = shader.get_uniform_location('uTipColor');
+      shader._uLetterSize  = shader.get_uniform_location('uLetterSize');
+      shader._uRandomness  = shader.get_uniform_location('uRandomness');
+      shader._uOverShoot   = shader.get_uniform_location('uOverShoot');
+
+      // Write all uniform values at the start of each animation.
+      shader.connect('begin-animation', (shader, settings) => {
+        const c1 =
+          Clutter.Color.from_string(settings.get_string('matrix-trail-color'))[1];
+        const c2 = Clutter.Color.from_string(settings.get_string('matrix-tip-color'))[1];
+
+        // clang-format off
+        shader.set_uniform_float(shader._uTrailColor, 3, [c1.red / 255, c1.green / 255, c1.blue / 255]);
+        shader.set_uniform_float(shader._uTipColor,   3, [c2.red / 255, c2.green / 255, c2.blue / 255]);
+        shader.set_uniform_float(shader._uLetterSize, 1, [settings.get_int('matrix-scale')]);
+        shader.set_uniform_float(shader._uRandomness, 1, [settings.get_double('matrix-randomness')]);
+        shader.set_uniform_float(shader._uOverShoot,  1, [settings.get_double('matrix-overshoot')]);
+        // clang-format on
+      });
+
+      // This is required to bind the font texture for drawing. Sadly, this seems to be
+      // impossible under GNOME 3.3x as this.get_pipeline() is not available. It was
+      // called get_target() back then but this is not wrapped in GJS.
+      // https://gitlab.gnome.org/GNOME/mutter/-/blob/gnome-3-36/clutter/clutter/clutter-offscreen-effect.c#L598
+      shader.connect('update-animation', (shader) => {
+        const pipeline = shader.get_pipeline();
+
+        // Bind the font texture.
+        pipeline.set_layer_texture(1, this._fontTexture.get_texture());
+        pipeline.set_uniform_1i(shader._uFontTexture, 1);
+      });
+    });
+  }
+
   // ---------------------------------------------------------------------------- metadata
 
   // This effect is only available on GNOME Shell 40+.
-  static getMinShellVersion() {
+  getMinShellVersion() {
     return [40, 0];
   }
 
@@ -56,22 +103,21 @@ var Matrix = class Matrix {
   // 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').
-  static getNick() {
+  getNick() {
     return 'matrix';
   }
 
   // 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.
-  static getLabel() {
+  getLabel() {
     return _('Matrix');
   }
 
   // -------------------------------------------------------------------- API for prefs.js
 
   // This is called by the preferences dialog. It loads the settings page for this effect,
-  // binds all properties to the settings and appends the page to the main stack of the
+  // and binds all properties to the settings.
-  // preferences dialog.
+  getPreferences(dialog) {
-  static getPreferences(dialog) {
 
     // Add the settings page to the builder.
     dialog.getBuilder().add_from_resource('/ui/gtk4/Matrix.ui');
@@ -90,121 +136,10 @@ var Matrix = class Matrix {
 
   // ---------------------------------------------------------------- API for extension.js
 
-  // This is called from extension.js whenever a window is opened or closed with this
-  // effect. It returns an instance of the shader class, trying to reuse previously
-  // created shaders.
-  static getShader(actor, settings, forOpening) {
-    let shader;
-
-    if (freeShaders.length == 0) {
-      shader = new ShaderClass();
-    } else {
-      shader = freeShaders.pop();
-    }
-
-    shader.setUniforms(actor, settings, forOpening);
-
-    return shader;
-  }
-
   // 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+.
-  static getActorScale(settings) {
+  getActorScale(settings) {
     return {x: 1.0, y: 1.0 + settings.get_double('matrix-overshoot')};
   }
-
-  // This is called from extension.js if the extension is disabled. This should free all
-  // static resources.
-  static cleanUp() {
-    freeShaders = [];
-    fontTexture = null;
-  }
-}
-
-
-//////////////////////////////////////////////////////////////////////////////////////////
-// The shader class for this effect will only be registered in GNOME Shell's process    //
-// (not in the preferences process). It's done this way as Clutter may not be installed //
-// on the system and therefore the preferences would crash.                             //
-//////////////////////////////////////////////////////////////////////////////////////////
-
-if (utils.isInShellProcess()) {
-
-  const {Clutter, GdkPixbuf, Cogl, Shell} = imports.gi;
-
-  ShaderClass = GObject.registerClass({}, class ShaderClass extends Shell.GLSLEffect {
-    // This is called when the effect is used for the first time. This can be used to
-    // store all required uniform locations.
-    _init() {
-      super._init();
-
-      // Load the font texture.
-      if (fontTexture == null) {
-        const fontData = GdkPixbuf.Pixbuf.new_from_resource('/img/matrixFont.png');
-        fontTexture    = new Clutter.Image();
-        fontTexture.set_data(
-          fontData.get_pixels(),
-          fontData.has_alpha ? Cogl.PixelFormat.RGBA_8888 : Cogl.PixelFormat.RGB_888,
-          fontData.width, fontData.height, fontData.rowstride);
-      }
-
-      this._uFontTexture = this.get_uniform_location('uFontTexture');
-      this._uTrailColor  = this.get_uniform_location('uTrailColor');
-      this._uTipColor    = this.get_uniform_location('uTipColor');
-      this._uLetterSize  = this.get_uniform_location('uLetterSize');
-      this._uRandomness  = this.get_uniform_location('uRandomness');
-      this._uOverShoot   = this.get_uniform_location('uOverShoot');
-    }
-
-    // This is called each time the effect is used. This can be used to retrieve the
-    // configuration from the settings and update all uniforms accordingly.
-    setUniforms(actor, settings, forOpening) {
-      const c1 = Clutter.Color.from_string(settings.get_string('matrix-trail-color'))[1];
-      const c2 = Clutter.Color.from_string(settings.get_string('matrix-tip-color'))[1];
-
-      // clang-format off
-      this.set_uniform_float(this._uTrailColor, 3, [c1.red / 255, c1.green / 255, c1.blue / 255]);
-      this.set_uniform_float(this._uTipColor,   3, [c2.red / 255, c2.green / 255, c2.blue / 255]);
-      this.set_uniform_float(this._uLetterSize, 1, [settings.get_int('matrix-scale')]);
-      this.set_uniform_float(this._uRandomness, 1, [settings.get_double('matrix-randomness')]);
-      this.set_uniform_float(this._uOverShoot,  1, [settings.get_double('matrix-overshoot')]);
-      // clang-format on
-    }
-
-    // This is called by extension.js when the shader is not used anymore. We will store
-    // this instance of the shader so that it can be re-used in th future.
-    free() {
-      freeShaders.push(this);
-    }
-
-    // This is called by the constructor. This means, it's only called when the effect
-    // is used for the first time. The technique for this effect was inspired by
-    // https://www.shadertoy.com/view/ldccW4, however the implementation is quite
-    // different as the letters drop only once and there is no need for a noise texture.
-    vfunc_build_pipeline() {
-      const code = utils.loadGLSLResource(`/shaders/${Matrix.getNick()}.glsl`);
-
-      // Match anything between the curly brackets of "void main() {...}".
-      const regex = RegExp('void main *\\(\\) *\\{([\\S\\s]+)\\}');
-      const match = regex.exec(code);
-
-      const declarations = code.substr(0, match.index);
-      const main         = match[1];
-
-      this.add_glsl_snippet(Shell.SnippetHook.FRAGMENT, declarations, main, true);
-    }
-
-    // This is overridden to bind the font texture for drawing. Sadly, this seems to be
-    // impossible under GNOME 3.3x as this.get_pipeline() is not available. It was called
-    // get_target() back then but this is not wrapped in GJS.
-    // https://gitlab.gnome.org/GNOME/mutter/-/blob/gnome-3-36/clutter/clutter/clutter-offscreen-effect.c#L598
-    vfunc_paint_target(node, paint_context) {
-      const pipeline = this.get_pipeline();
-      pipeline.set_layer_texture(1, fontTexture.get_texture());
-      pipeline.set_uniform_1i(this._uFontTexture, 1);
-
-      super.vfunc_paint_target(node, paint_context);
-    }
-  });
 }

src/Shader.js

@@ -0,0 +1,145 @@
+//////////////////////////////////////////////////////////////////////////////////////////
+//          )                                                   (                       //
+//       ( /(   (  (               )    (       (  (  (         )\ )    (  (            //
+//       )\()) ))\ )(   (         (     )\ )    )\))( )\  (    (()/( (  )\))(  (        //
+//      ((_)\ /((_|()\  )\ )      )\  '(()/(   ((_)()((_) )\ )  ((_)))\((_)()\ )\       //
+//      | |(_|_))( ((_)_(_/(    _((_))  )(_))  _(()((_|_)_(_/(  _| |((_)(()((_|(_)      //
+//      | '_ \ || | '_| ' \))  | '  \()| || |  \ V  V / | ' \)) _` / _ \ V  V (_-<      //
+//      |_.__/\_,_|_| |_||_|   |_|_|_|  \_, |   \_/\_/|_|_||_|\__,_\___/\_/\_//__/      //
+//                                 |__/                                                 //
+//                       Copyright (c) 2021 Simon Schneegans                            //
+//          Released under the GPLv3 or later. See LICENSE file for details.            //
+//////////////////////////////////////////////////////////////////////////////////////////
+
+'use strict';
+
+const {Gio, Shell, GObject, Clutter} = imports.gi;
+const ByteArray                      = imports.byteArray;
+
+const ExtensionUtils = imports.misc.extensionUtils;
+const Me             = imports.misc.extensionUtils.getCurrentExtension();
+const utils          = Me.imports.src.utils;
+
+//////////////////////////////////////////////////////////////////////////////////////////
+// This is the base class for all shaders of Burn-My-Windows. It automagically loads    //
+// the shader's source code from the resource file resources/shaders/<nick>.glsl and    //
+// ensures that some standard uniforms are always updated.                              //
+// Using Shell.GLSLEffect as a base class has some benefits and some drawbacks. The     //
+// main benefit when compared to Clutter.ShaderEffect is that setting uniforms of types //
+// vec2, vec3 or vec4 is supported via the API (with Clutter.ShaderEffect the GJS       //
+// binding does not work properly). However, there are two drawbacks: On the one hand,  //
+// the shader source code is cached statically - this mean if we want to have a         //
+// different shader, we have to derive a new class. Therefore, each effect has to       //
+// derive its own class from the class below. This is encapsulated in the               //
+// ShaderFactory, however it is some really awkward code. The other drawback is the     //
+// hard-coded use of straight alpha (as opposed to premultiplied). This makes the       //
+// shaders a bit more complicated than required.                                        //
+//                                                                                      //
+// The Shader fires two signals:                                                        //
+//   * begin-animation:    This is called each time a new animation is started. It can  //
+//                         be used to set uniform values which do not change during the //
+//                         animation.                                                   //
+//   * update-animation:   This is called at each frame during the animation. It can be //
+//                         used to set uniforms which change during the animation.      //
+//////////////////////////////////////////////////////////////////////////////////////////
+
+var Shader = GObject.registerClass(
+  {
+    Signals: {
+      'begin-animation':
+        {param_types: [Gio.Settings.$gtype, GObject.TYPE_BOOLEAN, Clutter.Actor.$gtype]},
+      'update-animation': {param_types: [GObject.TYPE_DOUBLE, GObject.TYPE_DOUBLE]}
+    }
+  },
+  class Shader extends Shell.GLSLEffect {  // --------------------------------------------
+    // The constructor automagically loads the shader's source code (in
+    // vfunc_build_pipeline()) from the resource file resources/shaders/<nick>.glsl
+    // resolving any #includes in this file.
+    _init(nick) {
+      this._nick = nick;
+
+      // This will call vfunc_build_pipeline().
+      super._init();
+
+      // These will be updated during the animation.
+      this._progress = 0;
+      this._time     = 0;
+
+      // Store standard uniform locations.
+      this._uForOpening = this.get_uniform_location('uForOpening');
+      this._uProgress   = this.get_uniform_location('uProgress');
+      this._uTime       = this.get_uniform_location('uTime');
+      this._uSize       = this.get_uniform_location('uSize');
+    }
+
+    // This is called once each time the shader is used.
+    beginAnimation(settings, forOpening, actor) {
+      this.set_uniform_float(this._uForOpening, 1, [forOpening]);
+      this.set_uniform_float(this._uSize, 2, [actor.width, actor.height]);
+
+      this.emit('begin-animation', settings, forOpening, actor);
+    }
+
+    // This is called at each frame during the animation.
+    updateAnimation(progress, time) {
+      this.set_uniform_float(this._uProgress, 1, [progress]);
+      this.set_uniform_float(this._uTime, 1, [time]);
+
+      // Store the current time and progress values. The corresponding signal is emitted a
+      // but later in vfunc_paint_target.
+      this._progress = progress;
+      this._time     = time;
+    }
+
+    // This is called by the constructor. This means, it's only called when the
+    // effect is used for the first time.
+    vfunc_build_pipeline() {
+
+      // Shell.GLSLEffect requires the declarations and the main source code as separate
+      // strings. As it's more convenient to store the in one GLSL file, we use a regex
+      // here to split the source code in two parts.
+      const code = this._loadGLSLResource(`/shaders/${this._nick}.glsl`);
+
+      // Match anything between the curly brackets of "void main() {...}".
+      const regex = RegExp('void main *\\(\\) *\\{([\\S\\s]+)\\}');
+      const match = regex.exec(code);
+
+      const declarations = code.substr(0, match.index);
+      const main         = match[1];
+
+      this.add_glsl_snippet(Shell.SnippetHook.FRAGMENT, declarations, main, true);
+    }
+
+    // We use this vfunc to trigger the update as it allows calling this.get_pipeline() in
+    // the handler. This could still be null if called from the updateAnimation() above.
+    vfunc_paint_target(...params) {
+      this.emit('update-animation', this._progress, this._time);
+      super.vfunc_paint_target(...params);
+    }
+
+    // --------------------------------------------------------------------- private stuff
+
+    // This loads the file at 'path' contained in the extension's resources to a
+    // JavaScript string.
+    _loadStringResource(path) {
+      const data = Gio.resources_lookup_data(path, 0);
+      return ByteArray.toString(ByteArray.fromGBytes(data));
+    }
+
+    // This loads a GLSL file from the extension's resources to a JavaScript string. Any
+    // #include statements in this file are replaced with the corresponding file contents.
+    _loadGLSLResource(path) {
+      let code = this._loadStringResource(path);
+
+      // This regex matches either #include "..." or #include <...>. The part between the
+      // brackets is captured in the capture group.
+      const regex = RegExp('#include ["<](.+)[">]', 'g');
+
+      code = code.replace(regex, (m, file) => {
+        return this._loadStringResource('/shaders/' + file);
+      });
+
+      // Add a trailing newline. Else the GLSL compiler complains...
+      return code + '\n';
+    }
+  });

src/ShaderFactory.js

@@ -0,0 +1,95 @@
+//////////////////////////////////////////////////////////////////////////////////////////
+//          )                                                   (                       //
+//       ( /(   (  (               )    (       (  (  (         )\ )    (  (            //
+//       )\()) ))\ )(   (         (     )\ )    )\))( )\  (    (()/( (  )\))(  (        //
+//      ((_)\ /((_|()\  )\ )      )\  '(()/(   ((_)()((_) )\ )  ((_)))\((_)()\ )\       //
+//      | |(_|_))( ((_)_(_/(    _((_))  )(_))  _(()((_|_)_(_/(  _| |((_)(()((_|(_)      //
+//      | '_ \ || | '_| ' \))  | '  \()| || |  \ V  V / | ' \)) _` / _ \ V  V (_-<      //
+//      |_.__/\_,_|_| |_||_|   |_|_|_|  \_, |   \_/\_/|_|_||_|\__,_\___/\_/\_//__/      //
+//                                 |__/                                                 //
+//                       Copyright (c) 2021 Simon Schneegans                            //
+//          Released under the GPLv3 or later. See LICENSE file for details.            //
+//////////////////////////////////////////////////////////////////////////////////////////
+
+'use strict';
+
+const GObject = imports.gi.GObject;
+
+const ExtensionUtils = imports.misc.extensionUtils;
+const Me             = imports.misc.extensionUtils.getCurrentExtension();
+
+//////////////////////////////////////////////////////////////////////////////////////////
+// Each effect of Burn-My-Windows owns an instance of this class. It is used to created //
+// shaders whenever a new one is required. It tries to re-use old shaders as much as    //
+// possible in order to avoid memory leaks.                                             //
+//////////////////////////////////////////////////////////////////////////////////////////
+
+var ShaderFactory = class ShaderFactory {
+
+  // Creates a new ShaderFactory. Requires the nick of the effect and a callback function
+  // which will be called whenever a new shader is created.
+  constructor(nick, setupFunc) {
+    // The _freeShaders array contains previously created shaders which are not currently
+    // in use.
+    this._freeShaders = [];
+
+    // The nick of the effect is required when creating new shaders as it's part of the
+    // GLSL source code file name.
+    this._nick = nick;
+
+    // Store the setup callback.
+    this._setupFunc = setupFunc;
+  }
+
+  // ---------------------------------------------------------------- API for extension.js
+
+  // This is called from extension.js whenever a window is opened or closed. It returns an
+  // instance of the shader class, trying to reuse previously created shaders. If a new
+  // shader instance is required, it calls creates a new one and calls the setupFunc
+  // thereafter.
+  getShader() {
+    let shader;
+
+    // If there are currently no free shaders, we have to create a new one.
+    if (this._freeShaders.length == 0) {
+
+      // Since Shell.GLSLEffect caches the shader source per class (not per instance), we
+      // have to derive a new shader type for each effect. The type name contains the nick
+      // of the effect to make it unique.
+      const typeName = `BurnMyWindowsShader_${this._nick}`;
+
+      // Only try to register the new type once.
+      if (GObject.type_from_name(typeName) == null) {
+        const outerThis = this;
+        GObject.registerClass({GTypeName: typeName},
+                              class Shader extends Me.imports.src.Shader.Shader {
+          // This will actually load the GLSL source code from the resources.
+          _init() {
+            super._init(outerThis._nick);
+          }
+
+          // This can be called to mark this instance to be re-usable.
+          returnToFactory() {
+            outerThis._freeShaders.push(this);
+          }
+        });
+      }
+
+      // Now create a niew instance of the newly registered shader type.
+      // GObject.Object.new is only available with newer versions of GJS.
+      if (GObject.Object.new) {
+        shader = GObject.Object.new(GObject.type_from_name(typeName), {});
+      } else {
+        shader = GObject.Object.newv(GObject.type_from_name(typeName), []);
+      }
+
+      // Call the provided setup callback.
+      this._setupFunc(shader);
+
+    } else {
+      shader = this._freeShaders.pop();
+    }
+
+    return shader;
+  }
+}

src/SnapOfDisintegration.js

@@ -20,6 +20,7 @@ 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 effects dissolves your windows into a cloud of dust. For this, it uses an       //
@@ -31,26 +32,74 @@ const utils          = Me.imports.src.utils;
 // documentation of vfunc_paint_target further down in this file.                       //
 //////////////////////////////////////////////////////////////////////////////////////////
 
-// The shader class for this effect is registered further down in this file. When this
+// The effect class can be used to get some metadata (like the effect's name or supported
-// effect is used for the first time, an instance of this shader class is created. Once
+// GNOME Shell versions), to initialize the respective page of the settings dialog, as
-// the effect is finished, the shader will be stored in the freeShaders array and will
+// well as to create the actual shader for the effect.
-// then be reused if a new shader is requested. ShaderClass which will be used whenever
-// this effect is used.
-let ShaderClass = null;
-let freeShaders = [];
-
-// This texture will be loaded when the effect is used for the first time.
-let dustTexture = null;
-
-// The effect class is completely static. It 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 SnapOfDisintegration = class SnapOfDisintegration {
 
+  // 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 these modules in this function as they are not available in the
+      // preferences process. This callback is only called within GNOME Shell's process.
+      const {Clutter, GdkPixbuf, Cogl} = imports.gi;
+
+      // Create the texture in the first call.
+      if (!this._dustTexture) {
+        const dustData    = GdkPixbuf.Pixbuf.new_from_resource('/img/dust.png');
+        this._dustTexture = new Clutter.Image();
+        this._dustTexture.set_data(dustData.get_pixels(), Cogl.PixelFormat.RGB_888,
+                                   dustData.width, dustData.height, dustData.rowstride);
+      }
+
+      // Store uniform locations of newly created shaders.
+      shader._uDustTexture = shader.get_uniform_location('uDustTexture');
+      shader._uDustColor   = shader.get_uniform_location('uDustColor');
+      shader._uSeed        = shader.get_uniform_location('uSeed');
+      shader._uDustScale   = shader.get_uniform_location('uDustScale');
+
+      // Write all uniform values at the start of each animation.
+      shader.connect('begin-animation', (shader, settings) => {
+        // The dust particles will fade to this color over time.
+        const c = Clutter.Color.from_string(settings.get_string('snap-color'))[1];
+
+        // If we are currently performing integration test, the animation uses a fixed
+        // seed.
+        const testMode = settings.get_boolean('test-mode');
+
+        // clang-format off
+        shader.set_uniform_float(shader._uDustColor, 4, [c.red / 255, c.green / 255, c.blue / 255, c.alpha / 255]);
+        shader.set_uniform_float(shader._uSeed,      2, [testMode ? 0 : Math.random(), testMode ? 0 : Math.random()]);
+        shader.set_uniform_float(shader._uDustScale, 1, [settings.get_double('snap-scale')]);
+        // clang-format on
+      });
+
+      // This is required to bind the dust texture for drawing. Sadly, this seems to be
+      // impossible under GNOME 3.3x as this.get_pipeline() is not available. It was
+      // called get_target() back then but this is not wrapped in GJS.
+      // https://gitlab.gnome.org/GNOME/mutter/-/blob/gnome-3-36/clutter/clutter/clutter-offscreen-effect.c#L598
+      shader.connect('update-animation', (shader) => {
+        const pipeline = shader.get_pipeline();
+
+        // Use linear filtering for the window texture.
+        pipeline.set_layer_filters(0, Cogl.PipelineFilter.LINEAR,
+                                   Cogl.PipelineFilter.LINEAR);
+
+        // Bind the dust texture.
+        pipeline.set_layer_texture(1, this._dustTexture.get_texture());
+        pipeline.set_layer_wrap_mode(1, Cogl.PipelineWrapMode.REPEAT);
+        pipeline.set_uniform_1i(shader._uDustTexture, 1);
+      });
+    });
+  }
+
   // ---------------------------------------------------------------------------- metadata
 
   // This effect is only available on GNOME Shell 40+.
-  static getMinShellVersion() {
+  getMinShellVersion() {
     return [40, 0];
   }
 
@@ -58,22 +107,21 @@ var SnapOfDisintegration = class SnapOfDisintegration {
   // 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').
-  static getNick() {
+  getNick() {
     return 'snap';
   }
 
   // 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.
-  static getLabel() {
+  getLabel() {
     return _('Snap of Disintegration');
   }
 
   // -------------------------------------------------------------------- API for prefs.js
 
   // This is called by the preferences dialog. It loads the settings page for this effect,
-  // binds all properties to the settings and appends the page to the main stack of the
+  // and binds all properties to the settings.
-  // preferences dialog.
+  getPreferences(dialog) {
-  static getPreferences(dialog) {
 
     // Add the settings page to the builder.
     dialog.getBuilder().add_from_resource('/ui/gtk4/SnapOfDisintegration.ui');
@@ -89,119 +137,10 @@ var SnapOfDisintegration = class SnapOfDisintegration {
 
   // ---------------------------------------------------------------- API for extension.js
 
-  // This is called from extension.js whenever a window is opened or closed with this
-  // effect. It returns an instance of the shader class, trying to reuse previously
-  // created shaders.
-  static getShader(actor, settings, forOpening) {
-    let shader;
-
-    if (freeShaders.length == 0) {
-      shader = new ShaderClass();
-    } else {
-      shader = freeShaders.pop();
-    }
-
-    shader.setUniforms(actor, settings, forOpening);
-
-    return shader;
-  }
-
   // 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+.
-  static getActorScale(settings) {
+  getActorScale(settings) {
     return {x: 1.2, y: 1.2};
   }
-
-  // This is called from extension.js if the extension is disabled. This should free all
-  // static resources.
-  static cleanUp() {
-    freeShaders = [];
-    dustTexture = null;
-  }
-}
-
-
-//////////////////////////////////////////////////////////////////////////////////////////
-// The shader class for this effect will only be registered in GNOME Shell's process    //
-// (not in the preferences process). It's done this way as Clutter may not be installed //
-// on the system and therefore the preferences would crash.                             //
-//////////////////////////////////////////////////////////////////////////////////////////
-
-if (utils.isInShellProcess()) {
-
-  const {Clutter, GdkPixbuf, Cogl, Shell} = imports.gi;
-
-  ShaderClass = GObject.registerClass({}, class ShaderClass extends Shell.GLSLEffect {
-    // This is called when the effect is used for the first time. This can be used to
-    // store all required uniform locations.
-    _init() {
-      super._init();
-
-      // Load the dust texture.
-      if (dustTexture == null) {
-        const dustData = GdkPixbuf.Pixbuf.new_from_resource('/img/dust.png');
-        dustTexture    = new Clutter.Image();
-        dustTexture.set_data(dustData.get_pixels(), Cogl.PixelFormat.RGB_888,
-                             dustData.width, dustData.height, dustData.rowstride);
-      }
-
-      this._uDustTexture = this.get_uniform_location('uDustTexture');
-      this._uDustColor   = this.get_uniform_location('uDustColor');
-      this._uSeed        = this.get_uniform_location('uSeed');
-      this._uDustScale   = this.get_uniform_location('uDustScale');
-    }
-
-    // This is called each time the effect is used. This can be used to retrieve the
-    // configuration from the settings and update all uniforms accordingly.
-    setUniforms(actor, settings, forOpening) {
-      // The dust particles will fade to this color over time.
-      const c = Clutter.Color.from_string(settings.get_string('snap-color'))[1];
-
-      // If we are currently performing integration test, the animation uses a fixed seed.
-      const testMode = settings.get_boolean('test-mode');
-
-      // clang-format off
-      this.set_uniform_float(this._uDustColor, 4, [c.red / 255, c.green / 255, c.blue / 255, c.alpha / 255]);
-      this.set_uniform_float(this._uSeed,      2, [testMode ? 0 : Math.random(), testMode ? 0 : Math.random()]);
-      this.set_uniform_float(this._uDustScale, 1, [settings.get_double('snap-scale')]);
-      // clang-format on
-    }
-
-    // This is called by extension.js when the shader is not used anymore. We will store
-    // this instance of the shader so that it can be re-used in th future.
-    free() {
-      freeShaders.push(this);
-    }
-
-    // This is called by the constructor. This means, it's only called when the effect
-    // is used for the first time.
-    vfunc_build_pipeline() {
-      const code =
-        utils.loadGLSLResource(`/shaders/${SnapOfDisintegration.getNick()}.glsl`);
-
-      // Match anything between the curly brackets of "void main() {...}".
-      const regex = RegExp('void main *\\(\\) *\\{([\\S\\s]+)\\}');
-      const match = regex.exec(code);
-
-      const declarations = code.substr(0, match.index);
-      const main         = match[1];
-
-      this.add_glsl_snippet(Shell.SnippetHook.FRAGMENT, declarations, main, true);
-    }
-
-    // This is overridden to bind the dust texture for drawing. Sadly, this seems to be
-    // impossible under GNOME 3.3x as this.get_pipeline() is not available. It was called
-    // get_target() back then but this is not wrapped in GJS.
-    // https://gitlab.gnome.org/GNOME/mutter/-/blob/gnome-3-36/clutter/clutter/clutter-offscreen-effect.c#L598
-    vfunc_paint_target(node, paint_context) {
-      const pipeline = this.get_pipeline();
-      pipeline.set_layer_filters(0, Cogl.PipelineFilter.LINEAR,
-                                 Cogl.PipelineFilter.LINEAR);
-      pipeline.set_layer_texture(1, dustTexture.get_texture());
-      pipeline.set_layer_wrap_mode(1, Cogl.PipelineWrapMode.REPEAT);
-      pipeline.set_uniform_1i(this._uDustTexture, 1);
-      super.vfunc_paint_target(node, paint_context);
-    }
-  });
 }

src/TRexAttack.js

@@ -20,6 +20,7 @@ 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 tears your windows apart with a series of violent scratches!             //
@@ -27,26 +28,76 @@ const utils          = Me.imports.src.utils;
 // documentation of vfunc_paint_target further down in this file.                       //
 //////////////////////////////////////////////////////////////////////////////////////////
 
-// The shader class for this effect is registered further down in this file. When this
+// The effect class can be used to get some metadata (like the effect's name or supported
-// effect is used for the first time, an instance of this shader class is created. Once
+// GNOME Shell versions), to initialize the respective page of the settings dialog, as
-// the effect is finished, the shader will be stored in the freeShaders array and will
+// well as to create the actual shader for the effect.
-// then be reused if a new shader is requested. ShaderClass which will be used whenever
-// this effect is used.
-let ShaderClass = null;
-let freeShaders = [];
-
-// This texture will be loaded when the effect is used for the first time.
-let clawTexture = null;
-
-// The effect class is completely static. It 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 TRexAttack = class TRexAttack {
 
+  // 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 these modules in this function as they are not available in the
+      // preferences process. This callback is only called within GNOME Shell's process.
+      const {Clutter, GdkPixbuf, Cogl} = imports.gi;
+
+      // Create the texture in the first call.
+      if (!this._clawTexture) {
+        const clawData    = GdkPixbuf.Pixbuf.new_from_resource('/img/claws.png');
+        this._clawTexture = new Clutter.Image();
+        this._clawTexture.set_data(clawData.get_pixels(), Cogl.PixelFormat.RGB_888,
+                                   clawData.width, clawData.height, clawData.rowstride);
+      }
+
+      // Store uniform locations of newly created shaders.
+      shader._uClawTexture   = shader.get_uniform_location('uClawTexture');
+      shader._uFlashColor    = shader.get_uniform_location('uFlashColor');
+      shader._uSeed          = shader.get_uniform_location('uSeed');
+      shader._uClawSize      = shader.get_uniform_location('uClawSize');
+      shader._uNumClaws      = shader.get_uniform_location('uNumClaws');
+      shader._uWarpIntensity = shader.get_uniform_location('uWarpIntensity');
+
+      // 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('claw-scratch-color'))[1];
+
+        // If we are currently performing integration test, the animation uses a fixed
+        // seed.
+        const testMode = settings.get_boolean('test-mode');
+
+        // clang-format off
+        shader.set_uniform_float(shader._uFlashColor,    4, [c.red / 255, c.green / 255, c.blue / 255, c.alpha / 255]);
+        shader.set_uniform_float(shader._uSeed,          2, [testMode ? 0 : Math.random(), testMode ? 0 : Math.random()]);
+        shader.set_uniform_float(shader._uClawSize,      1, [settings.get_double('claw-scratch-scale')]);
+        shader.set_uniform_float(shader._uNumClaws,      1, [settings.get_int('claw-scratch-count')]);
+        shader.set_uniform_float(shader._uWarpIntensity, 1, [settings.get_double('claw-scratch-warp')]);
+        // clang-format on
+      });
+
+      // This is required to bind the claw texture for drawing. Sadly, this seems to be
+      // impossible under GNOME 3.3x as this.get_pipeline() is not available. It was
+      // called get_target() back then but this is not wrapped in GJS.
+      // https://gitlab.gnome.org/GNOME/mutter/-/blob/gnome-3-36/clutter/clutter/clutter-offscreen-effect.c#L598
+      shader.connect('update-animation', (shader) => {
+        const pipeline = shader.get_pipeline();
+
+        // Use linear filtering for the window texture.
+        pipeline.set_layer_filters(0, Cogl.PipelineFilter.LINEAR,
+                                   Cogl.PipelineFilter.LINEAR);
+
+        // Bind the claw texture.
+        pipeline.set_layer_texture(1, this._clawTexture.get_texture());
+        pipeline.set_uniform_1i(shader._uClawTexture, 1);
+      });
+    });
+  }
+
   // ---------------------------------------------------------------------------- metadata
 
   // This effect is only available on GNOME Shell 40+.
-  static getMinShellVersion() {
+  getMinShellVersion() {
     return [40, 0];
   }
 
@@ -54,22 +105,21 @@ var TRexAttack = class TRexAttack {
   // 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').
-  static getNick() {
+  getNick() {
     return 'trex';
   }
 
   // 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.
-  static getLabel() {
+  getLabel() {
     return _('T-Rex Attack');
   }
 
   // -------------------------------------------------------------------- API for prefs.js
 
   // This is called by the preferences dialog. It loads the settings page for this effect,
-  // binds all properties to the settings and appends the page to the main stack of the
+  // and binds all properties to the settings.
-  // preferences dialog.
+  getPreferences(dialog) {
-  static getPreferences(dialog) {
 
     // Add the settings page to the builder.
     dialog.getBuilder().add_from_resource('/ui/gtk4/TRexAttack.ui');
@@ -87,120 +137,11 @@ var TRexAttack = class TRexAttack {
 
   // ---------------------------------------------------------------- API for extension.js
 
-  // This is called from extension.js whenever a window is opened or closed with this
-  // effect. It returns an instance of the shader class, trying to reuse previously
-  // created shaders.
-  static getShader(actor, settings, forOpening) {
-    let shader;
-
-    if (freeShaders.length == 0) {
-      shader = new ShaderClass();
-    } else {
-      shader = freeShaders.pop();
-    }
-
-    shader.setUniforms(actor, settings, forOpening);
-
-    return shader;
-  }
-
   // 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+.
-  static getActorScale(settings) {
+  getActorScale(settings) {
     const scale = 1.0 + 0.5 * settings.get_double('claw-scratch-warp');
     return {x: scale, y: scale};
   }
-
-  // This is called from extension.js if the extension is disabled. This should free all
-  // static resources.
-  static cleanUp() {
-    freeShaders = [];
-    clawTexture = null;
-  }
-}
-
-
-//////////////////////////////////////////////////////////////////////////////////////////
-// The shader class for this effect will only be registered in GNOME Shell's process    //
-// (not in the preferences process). It's done this way as Clutter may not be installed //
-// on the system and therefore the preferences would crash.                             //
-//////////////////////////////////////////////////////////////////////////////////////////
-
-if (utils.isInShellProcess()) {
-
-  const {Clutter, GdkPixbuf, Cogl, Shell} = imports.gi;
-
-  ShaderClass = GObject.registerClass({}, class ShaderClass extends Shell.GLSLEffect {
-    // This is called when the effect is used for the first time. This can be used to
-    // store all required uniform locations.
-    _init() {
-      super._init();
-
-      // Load the claw texture.
-      if (clawTexture == null) {
-        const clawData = GdkPixbuf.Pixbuf.new_from_resource('/img/claws.png');
-        clawTexture    = new Clutter.Image();
-        clawTexture.set_data(clawData.get_pixels(), Cogl.PixelFormat.RGB_888,
-                             clawData.width, clawData.height, clawData.rowstride);
-      }
-
-      this._uClawTexture   = this.get_uniform_location('uClawTexture');
-      this._uFlashColor    = this.get_uniform_location('uFlashColor');
-      this._uSeed          = this.get_uniform_location('uSeed');
-      this._uClawSize      = this.get_uniform_location('uClawSize');
-      this._uNumClaws      = this.get_uniform_location('uNumClaws');
-      this._uWarpIntensity = this.get_uniform_location('uWarpIntensity');
-    }
-
-    // This is called each time the effect is used. This can be used to retrieve the
-    // configuration from the settings and update all uniforms accordingly.
-    setUniforms(actor, settings, forOpening) {
-      const c = Clutter.Color.from_string(settings.get_string('claw-scratch-color'))[1];
-
-      // If we are currently performing integration test, the animation uses a fixed seed.
-      const testMode = settings.get_boolean('test-mode');
-
-      // clang-format off
-      this.set_uniform_float(this._uFlashColor,    4, [c.red / 255, c.green / 255, c.blue / 255, c.alpha / 255]);
-      this.set_uniform_float(this._uSeed,          2, [testMode ? 0 : Math.random(), testMode ? 0 : Math.random()]);
-      this.set_uniform_float(this._uClawSize,      1, [settings.get_double('claw-scratch-scale')]);
-      this.set_uniform_float(this._uNumClaws,      1, [settings.get_int('claw-scratch-count')]);
-      this.set_uniform_float(this._uWarpIntensity, 1, [settings.get_double('claw-scratch-warp')]);
-      // clang-format on
-    }
-
-    // This is called by extension.js when the shader is not used anymore. We will store
-    // this instance of the shader so that it can be re-used in th future.
-    free() {
-      freeShaders.push(this);
-    }
-
-    // This is called by the constructor. This means, it's only called when the effect
-    // is used for the first time.
-    vfunc_build_pipeline() {
-      const code = utils.loadGLSLResource(`/shaders/${TRexAttack.getNick()}.glsl`);
-
-      // Match anything between the curly brackets of "void main() {...}".
-      const regex = RegExp('void main *\\(\\) *\\{([\\S\\s]+)\\}');
-      const match = regex.exec(code);
-
-      const declarations = code.substr(0, match.index);
-      const main         = match[1];
-
-      this.add_glsl_snippet(Shell.SnippetHook.FRAGMENT, declarations, main, true);
-    }
-
-    // This is overridden to bind the claw texture for drawing. Sadly, this seems to be
-    // impossible under GNOME 3.3x as this.get_pipeline() is not available. It was called
-    // get_target() back then but this is not wrapped in GJS.
-    // https://gitlab.gnome.org/GNOME/mutter/-/blob/gnome-3-36/clutter/clutter/clutter-offscreen-effect.c#L598
-    vfunc_paint_target(node, paint_context) {
-      const pipeline = this.get_pipeline();
-      pipeline.set_layer_texture(1, clawTexture.get_texture());
-      pipeline.set_uniform_1i(this._uClawTexture, 1);
-
-      super.vfunc_paint_target(node, paint_context);
-    }
-  });
 }

src/TVEffect.js

@@ -20,6 +20,7 @@ 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 hides the actor by making it first transparent from top and bottom       //
@@ -27,23 +28,38 @@ const utils          = Me.imports.src.utils;
 // the center.                                                                          //
 //////////////////////////////////////////////////////////////////////////////////////////
 
-// The shader class for this effect is registered further down in this file. When this
+// The effect class can be used to get some metadata (like the effect's name or supported
-// effect is used for the first time, an instance of this shader class is created. Once
+// GNOME Shell versions), to initialize the respective page of the settings dialog, as
-// the effect is finished, the shader will be stored in the freeShaders array and will
+// well as to create the actual shader for the effect.
-// then be reused if a new shader is requested. ShaderClass which will be used whenever
-// this effect is used.
-let ShaderClass = null;
-let freeShaders = [];
-
-// The effect class is completely static. It 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 TVEffect = class TVEffect {
 
+  // 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._uColor = shader.get_uniform_location('uColor');
+
+      // 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('tv-effect-color'))[1];
+        shader.set_uniform_float(shader._uColor, 3,
+                                 [c.red / 255, c.green / 255, c.blue / 255]);
+      });
+    });
+  }
+
   // ---------------------------------------------------------------------------- metadata
 
   // The effect is available on all GNOME Shell versions supported by this extension.
-  static getMinShellVersion() {
+  getMinShellVersion() {
     return [3, 36];
   }
 
@@ -51,22 +67,21 @@ var TVEffect = class TVEffect {
   // 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').
-  static getNick() {
+  getNick() {
     return 'tv';
   }
 
   // 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.
-  static getLabel() {
+  getLabel() {
     return _('TV Effect');
   }
 
   // -------------------------------------------------------------------- API for prefs.js
 
   // This is called by the preferences dialog. It loads the settings page for this effect,
-  // binds all properties to the settings and appends the page to the main stack of the
+  // and binds all properties to the settings.
-  // preferences dialog.
+  getPreferences(dialog) {
-  static getPreferences(dialog) {
 
     // Add the settings page to the builder.
     dialog.getBuilder().add_from_resource(`/ui/${utils.getGTKString()}/TVEffect.ui`);
@@ -81,83 +96,10 @@ var TVEffect = class TVEffect {
 
   // ---------------------------------------------------------------- API for extension.js
 
-  // This is called from extension.js whenever a window is opened or closed with this
-  // effect. It returns an instance of the shader class, trying to reuse previously
-  // created shaders.
-  static getShader(actor, settings, forOpening) {
-    let shader;
-
-    if (freeShaders.length == 0) {
-      shader = new ShaderClass();
-    } else {
-      shader = freeShaders.pop();
-    }
-
-    shader.setUniforms(actor, settings, forOpening);
-
-    return shader;
-  }
-
   // 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+.
-  static getActorScale(settings) {
+  getActorScale(settings) {
     return {x: 1.0, y: 1.0};
   }
-
-  // This is called from extension.js if the extension is disabled. This should free all
-  // static resources.
-  static cleanUp() {
-    freeShaders = [];
-  }
-}
-
-
-//////////////////////////////////////////////////////////////////////////////////////////
-// The shader class for this effect will only be registered in GNOME Shell's process    //
-// (not in the preferences process). It's done this way as Clutter may not be installed //
-// on the system and therefore the preferences would crash.                             //
-//////////////////////////////////////////////////////////////////////////////////////////
-
-if (utils.isInShellProcess()) {
-
-  const {Clutter, Shell} = imports.gi;
-
-  ShaderClass = GObject.registerClass({}, class ShaderClass extends Shell.GLSLEffect {
-    // This is called when the effect is used for the first time. This can be used to
-    // store all required uniform locations.
-    _init() {
-      super._init();
-
-      this._uColor = this.get_uniform_location('uColor');
-    }
-
-    // This is called each time the effect is used. This can be used to retrieve the
-    // configuration from the settings and update all uniforms accordingly.
-    setUniforms(actor, settings, forOpening) {
-      const c = Clutter.Color.from_string(settings.get_string('tv-effect-color'))[1];
-      this.set_uniform_float(this._uColor, 3, [c.red / 255, c.green / 255, c.blue / 255]);
-    }
-
-    // This is called by extension.js when the shader is not used anymore. We will store
-    // this instance of the shader so that it can be re-used in th future.
-    free() {
-      freeShaders.push(this);
-    }
-
-    // This is called by the constructor. This means, it's only called when the effect
-    // is used for the first time.
-    vfunc_build_pipeline() {
-      const code = utils.loadGLSLResource(`/shaders/${TVEffect.getNick()}.glsl`);
-
-      // Match anything between the curly brackets of "void main() {...}".
-      const regex = RegExp('void main *\\(\\) *\\{([\\S\\s]+)\\}');
-      const match = regex.exec(code);
-
-      const declarations = code.substr(0, match.index);
-      const main         = match[1];
-
-      this.add_glsl_snippet(Shell.SnippetHook.FRAGMENT, declarations, main, true);
-    }
-  });
 }

src/Wisps.js

@@ -20,52 +20,76 @@ 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 lets your windows be carried to the realm of dreams by some little       //
 // fairies. It's implemented with several overlaid grids of randomly moving points.     //
 //////////////////////////////////////////////////////////////////////////////////////////
 
-// The shader class for this effect is registered further down in this file. When this
+// The effect class can be used to get some metadata (like the effect's name or supported
-// effect is used for the first time, an instance of this shader class is created. Once
+// GNOME Shell versions), to initialize the respective page of the settings dialog, as
-// the effect is finished, the shader will be stored in the freeShaders array and will
+// well as to create the actual shader for the effect.
-// then be reused if a new shader is requested. ShaderClass which will be used whenever
-// this effect is used.
-let ShaderClass = null;
-let freeShaders = [];
-
-// 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').
 var Wisps = class Wisps {
 
+  // 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');
+
+      // 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('wisps-color'))[1];
+
+        // If we are currently performing integration test, the animation uses a fixed
+        // seed.
+        const testMode = settings.get_boolean('test-mode');
+
+        // clang-format off
+        shader.set_uniform_float(shader._uSeed,  2, [testMode ? 0 : Math.random(), 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('wisps-scale')]);
+        // clang-format on
+      });
+    });
+  }
+
   // ---------------------------------------------------------------------------- metadata
 
   // The effect is available on all GNOME Shell versions supported by this extension.
-  static getMinShellVersion() {
+  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. the '*-close-effect').
-  static getNick() {
+  getNick() {
     return 'wisps';
   }
 
   // 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.
-  static getLabel() {
+  getLabel() {
     return _('Wisps');
   }
 
   // -------------------------------------------------------------------- API for prefs.js
 
   // This is called by the preferences dialog. It loads the settings page for this effect,
-  // binds all properties to the settings and appends the page to the main stack of the
+  // and binds all properties to the settings.
-  // preferences dialog.
+  getPreferences(dialog) {
-  static getPreferences(dialog) {
 
     // Add the settings page to the builder.
     dialog.getBuilder().add_from_resource(`/ui/${utils.getGTKString()}/Wisps.ui`);
@@ -81,93 +105,10 @@ var Wisps = class Wisps {
 
   // ---------------------------------------------------------------- API for extension.js
 
-  // This is called from extension.js whenever a window is opened or closed with this
-  // effect. It returns an instance of the shader class, trying to reuse previously
-  // created shaders.
-  static getShader(actor, settings, forOpening) {
-    let shader;
-
-    if (freeShaders.length == 0) {
-      shader = new ShaderClass();
-    } else {
-      shader = freeShaders.pop();
-    }
-
-    shader.setUniforms(actor, settings, forOpening);
-
-    return shader;
-  }
-
   // 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+.
-  static getActorScale(settings) {
+  getActorScale(settings) {
     return {x: 1.0, y: 1.0};
   }
-
-  // This is called from extension.js if the extension is disabled. This should free all
-  // static resources.
-  static cleanUp() {
-    freeShaders = [];
-  }
-}
-
-
-//////////////////////////////////////////////////////////////////////////////////////////
-// The shader class for this effect will only be registered in GNOME Shell's process    //
-// (not in the preferences process). It's done this way as Clutter may not be installed //
-// on the system and therefore the preferences would crash.                             //
-//////////////////////////////////////////////////////////////////////////////////////////
-
-if (utils.isInShellProcess()) {
-
-  const {Clutter, Shell} = imports.gi;
-
-  ShaderClass = GObject.registerClass({}, class ShaderClass extends Shell.GLSLEffect {
-    // This is called when the effect is used for the first time. This can be used to
-    // store all required uniform locations.
-    _init() {
-      super._init();
-
-      this._uSeed  = this.get_uniform_location('uSeed');
-      this._uColor = this.get_uniform_location('uColor');
-      this._uScale = this.get_uniform_location('uScale');
-    }
-
-    // This is called each time the effect is used. This can be used to retrieve the
-    // configuration from the settings and update all uniforms accordingly.
-    setUniforms(actor, settings, forOpening) {
-      const c = Clutter.Color.from_string(settings.get_string('wisps-color'))[1];
-
-      // If we are currently performing integration test, the animation uses a fixed seed.
-      const testMode = settings.get_boolean('test-mode');
-
-      // clang-format off
-      this.set_uniform_float(this._uSeed,  2, [testMode ? 0 : Math.random(), testMode ? 0 : Math.random()]);
-      this.set_uniform_float(this._uColor, 3, [c.red / 255, c.green / 255, c.blue / 255]);
-      this.set_uniform_float(this._uScale, 1, [settings.get_double('wisps-scale')]);
-      // clang-format on
-    }
-
-    // This is called by extension.js when the shader is not used anymore. We will store
-    // this instance of the shader so that it can be re-used in th future.
-    free() {
-      freeShaders.push(this);
-    }
-
-    // This is called by the constructor. This means, it's only called when the effect
-    // is used for the first time.
-    vfunc_build_pipeline() {
-      const code = utils.loadGLSLResource(`/shaders/${Wisps.getNick()}.glsl`);
-
-      // Match anything between the curly brackets of "void main() {...}".
-      const regex = RegExp('void main *\\(\\) *\\{([\\S\\s]+)\\}');
-      const match = regex.exec(code);
-
-      const declarations = code.substr(0, match.index);
-      const main         = match[1];
-
-      this.add_glsl_snippet(Shell.SnippetHook.FRAGMENT, declarations, main, true);
-    }
-  });
 }

src/utils.js

@@ -13,8 +13,7 @@
 
 'use strict';
 
-const {Gtk, Gio} = imports.gi;
+const {Gtk} = imports.gi;
-const ByteArray  = imports.byteArray;
 
 // Returns the given argument, except for "alpha", "beta", and "rc". In these cases -3,
 // -2, and -1 are returned respectively.
@@ -66,12 +65,6 @@ function getGTKString() {
   return isGTK4() ? 'gtk4' : 'gtk3';
 }
 
-// This method returns true if called in GNOME Shell's process, false if called in the
-// preferences process.
-function isInShellProcess() {
-  return window.global && global.stage;
-}
-
 // This method returns true if the current GNOME Shell version matches the given
 // arguments.
 function shellVersionIs(major, minor) {
@@ -91,27 +84,3 @@ function shellVersionIsAtLeast(major, minor) {
 
   return false;
 }
-
-// This loads the file at 'path' contained in the extension's resources to a JavaScript
-// string.
-function loadStringResource(path) {
-  const data = Gio.resources_lookup_data(path, 0);
-  return ByteArray.toString(ByteArray.fromGBytes(data));
-}
-
-// This loads a GLSL file from the extension's resources to a JavaScript string. Any
-// #include statements in this file are replaced with the corresponding file contents.
-function loadGLSLResource(path) {
-  let code = loadStringResource(path);
-
-  // This regex matches either #include "..." or #include <...>. The part between the
-  // brackets is captured in the capture group.
-  const regex = RegExp('#include ["<](.+)[">]', 'g');
-
-  code = code.replace(regex, (m, file) => {
-    return loadStringResource('/shaders/' + file);
-  });
-
-  // Add a trailing newline. Else the GLSL compiler complains...
-  return code + '\n';
-}

tests/generate-references.sh

@@ -110,14 +110,12 @@ capture_effect() {
   set_setting "open-preview-effect" "${1}"
   set_setting "close-preview-effect" "${1}"
 
-  sleep 2
   do_in_pod gnome-extensions prefs "${EXTENSION}"
-  sleep 2
+  sleep 3
   capture "tests/references/${1}-open-${SESSION}-${FEDORA_VERSION}.png"
   send_keystroke "Alt+F4"
-  sleep 2
+  sleep 3
   capture "tests/references/${1}-close-${SESSION}-${FEDORA_VERSION}.png"
-  sleep 2
 }
 
 # ----------------------------------------------------- wait for the container to start up