🔧 Make doom effect work for opening windows

extension.js

@@ -434,7 +434,7 @@ class Extension {
     // windows are faded in / out scaled up / down slightly by GNOME Shell. Here, we tweak
     // the transitions so that nothing changes. The window stays opaque and is scaled to
     // actorScale.
-    const actorScale = effect.getActorScale(this._settings, actor);
+    const actorScale = effect.getActorScale(this._settings, forOpening, actor);
 
     // To make things deterministic during testing, we set the effect duration to 5
     // seconds.

resources/shaders/doom.frag

@@ -19,8 +19,10 @@ uniform float uVerticalScale;
 uniform float uPixelSize;
 
 void main() {
+  // We simply inverse the progress for opening windows.
+  float pixelateProgress = uForOpening ? 0.9 - uProgress : uProgress;
 
-  float pixelSize = ceil(uPixelSize * uProgress + 1.0);
+  float pixelSize = max(1.0, ceil(uPixelSize * pixelateProgress + 1.0));
   vec2 pixelGrid  = vec2(pixelSize) / uSize;
 
   vec2 texcoord = iTexCoord.st;
@@ -29,12 +31,19 @@ void main() {
   texcoord += pixelGrid * 0.5;
 
   float hScale = uHorizontalScale * uSize.x * 0.001;
-  float vScale = uVerticalScale * uSize.y * 0.0001;
-  float shift  = max(simplex2DFractal(texcoord.xx * hScale) * vScale +
-                      (1.0 + vScale * 0.8) * uProgress - 0.8 * vScale,
-                    0.0);
+  float vScale = uVerticalScale * uSize.y * 0.00002 * uActorScale;
 
-  texcoord.y -= uActorScale * shift;
+  float noise = simplex2DFractal(texcoord.xx * hScale) * 2.0 - 0.5;
+
+  float shiftProgress = uForOpening ? mix(-vScale - 1.0, 0.0, uProgress)
+                                    : mix(-vScale, 1.0 + vScale, uProgress);
+  float shift         = noise * vScale + shiftProgress;
+
+  if (uForOpening) {
+    texcoord.y -= 0.5 * uActorScale * min(shift, 0.0);
+  } else {
+    texcoord.y -= 0.5 * uActorScale * max(shift, 0.0);
+  }
 
   vec4 oColor = getInputColor(texcoord);
 

schemas/org.gnome.shell.extensions.burn-my-windows.gschema.xml

@@ -100,7 +100,7 @@
     </key>
 
     <key name="doom-animation-time" type="i">
-      <default>1500</default>
+      <default>1000</default>
       <summary>Doom Animation Time</summary>
       <description>The time the Doom effect takes.</description>
     </key>

src/Doom.js

@@ -46,7 +46,10 @@ var Doom = class {
 
       // Write all uniform values at the start of each animation.
       shader.connect('begin-animation', (shader, settings, forOpening, actor) => {
+        // For this effect, we scale the actor vertically so that it covers the entire
+        // screen. This ensures that the melted window will not be cut off.
         let actorScale = 2.0 * Math.max(1.0, global.stage.height / actor.height);
+
         // clang-format off
         shader.set_uniform_float(shader._uActorScale,      1, [actorScale]);
         shader.set_uniform_float(shader._uHorizontalScale, 1, [settings.get_double('doom-horizontal-scale')]);
@@ -103,7 +106,9 @@ var Doom = class {
   // The getActorScale() is called from extension.js to adjust the actor's size during the
   // animation. This is useful if the effect requires drawing something beyond the usual
   // bounds of the actor. This only works for GNOME 3.38+.
-  getActorScale(settings, actor) {
+  // For this effect, we scale the actor vertically so that it covers the entire screen.
+  // This ensures that the melted window will not be cut off.
+  getActorScale(settings, forOpening, actor) {
     let actorScale = 2.0 * Math.max(1.0, global.stage.height / actor.height);
     return {x: 1.0, y: actorScale};
   }