diff --git a/docs/changelog.md b/docs/changelog.md
index 364c815..c97f699 100644
--- a/docs/changelog.md
+++ b/docs/changelog.md
@@ -4,6 +4,10 @@
 
 **Release Date:** TBD
 
+#### Enhancements
+
+* The standard uniforms of all shaders have been updated: The window size is now passed as a `vec2` and there is a new `bool uForOpening` which is set to `true` if a window-open animation is ongoing, to `false` otherwise.
+
 #### Bug Fixes
 
 * **Fixed a major memory leak**. Now, shaders are not re-created anymore whenever a window is opened or closed. Instead, previously created shaders are re-used as often as possible. This requires that all settings are set as uniform values (previously they were injected into the shader source) which in turn requires that `Shell.GLSLEffect` is used instead of `Clutter.ShaderEffect`. This change also requires that all shaders now work with straight instead of premultiplied alpha. Anyways, a lot needed to be refactored for this fix and I hope that it did not bring too many visual changes.
diff --git a/docs/how-to-create-new-effects.md b/docs/how-to-create-new-effects.md
index 6957067..0194691 100644
--- a/docs/how-to-create-new-effects.md
+++ b/docs/how-to-create-new-effects.md
@@ -234,11 +234,11 @@ if (utils.isInShellProcess()) {
       const declarations = `
         // The code below injects some standard uniforms which will be updated during the
         // animation. This includes:
-        // uTexture:    Contains the texture of the window.
-        // uProgress:   A value which transitions from 0 to 1 during the entire animation.
-        // uTime:       A steadily increasing value in seconds.
-        // uSizeX:      The horizontal size of uTexture in pixels.
-        // uSizeY:      The vertical size of uTexture in pixels.
+        // 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.
         ${shaderSnippets.standardUniforms()}
 
         // The width of the fading effect is loaded from the settings.
diff --git a/extension.js b/extension.js
index 51ec11e..19dbac7 100644
--- a/extension.js
+++ b/extension.js
@@ -487,14 +487,15 @@ class Extension {
 
       // Update uniforms at each frame.
       transition.connect('new-frame', (t) => {
+        shader.set_uniform_float(shader.get_uniform_location('uForOpening'), 1,
+                                 [forOpening]);
         shader.set_uniform_float(shader.get_uniform_location('uProgress'), 1,
                                  [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('uSizeX'), 1, [actor.width]);
-        shader.set_uniform_float(shader.get_uniform_location('uSizeY'), 1,
-                                 [actor.height]);
+        shader.set_uniform_float(shader.get_uniform_location('uSize'), 2,
+                                 [actor.width, actor.height]);
       });
 
       // Remove the effect if the animation finished or was interrupted.
diff --git a/src/Apparition.js b/src/Apparition.js
index e7c31c4..df1a844 100644
--- a/src/Apparition.js
+++ b/src/Apparition.js
@@ -146,7 +146,6 @@ if (utils.isInShellProcess()) {
     _init() {
       super._init();
 
-      this._uForOpening = this.get_uniform_location('uForOpening');
       this._uSeed       = this.get_uniform_location('uSeed');
       this._uShake      = this.get_uniform_location('uShake');
       this._uTwirl      = this.get_uniform_location('uTwirl');
@@ -161,7 +160,6 @@ if (utils.isInShellProcess()) {
       const testMode = settings.get_boolean('test-mode');
 
       // clang-format off
-      this.set_uniform_float(this._uForOpening, 1, [forOpening]);
       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')]);
@@ -183,7 +181,6 @@ if (utils.isInShellProcess()) {
         // Inject some common shader snippets.
         ${shaderSnippets.standardUniforms()}
 
-        uniform bool  uForOpening;
         uniform vec2  uSeed;
         uniform float uShake;
         uniform float uTwirl;
diff --git a/src/BrokenGlass.js b/src/BrokenGlass.js
index fc22b7d..be7b770 100644
--- a/src/BrokenGlass.js
+++ b/src/BrokenGlass.js
@@ -167,7 +167,6 @@ if (utils.isInShellProcess()) {
                               shardData.width, shardData.height, shardData.rowstride);
       }
 
-      this._uForOpening   = this.get_uniform_location('uForOpening');
       this._uShardTexture = this.get_uniform_location('uShardTexture');
       this._uSeed         = this.get_uniform_location('uSeed');
       this._uEpicenter    = this.get_uniform_location('uEpicenter');
@@ -198,7 +197,6 @@ if (utils.isInShellProcess()) {
       const testMode = settings.get_boolean('test-mode');
 
       // clang-format off
-      this.set_uniform_float(this._uForOpening, 1, [forOpening]);
       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')]);
@@ -220,7 +218,6 @@ if (utils.isInShellProcess()) {
         // Inject some common shader snippets.
         ${shaderSnippets.standardUniforms()}
 
-        uniform bool      uForOpening;
         uniform sampler2D uShardTexture;
         uniform vec2      uSeed;
         uniform vec2      uEpicenter;
@@ -265,7 +262,7 @@ if (utils.isInShellProcess()) {
           coords += uEpicenter;
 
           // Retrieve information from the shard texture for our layer.
-          vec2 shardCoords = (coords + uSeed) * vec2(uSizeX, uSizeY) / uShardScale / 500.0;
+          vec2 shardCoords = (coords + uSeed) * uSize / uShardScale / 500.0;
           vec2 shardMap = texture2D(uShardTexture, shardCoords).rg;
 
           // The green channel contains a random value in [0..1] for each shard. We
diff --git a/src/EnergizeA.js b/src/EnergizeA.js
index 0bd94b9..8cfc328 100644
--- a/src/EnergizeA.js
+++ b/src/EnergizeA.js
@@ -140,9 +140,8 @@ if (utils.isInShellProcess()) {
     _init() {
       super._init();
 
-      this._uForOpening = this.get_uniform_location('uForOpening');
-      this._uColor      = this.get_uniform_location('uColor');
-      this._uScale      = this.get_uniform_location('uScale');
+      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
@@ -151,9 +150,8 @@ if (utils.isInShellProcess()) {
       const c = Clutter.Color.from_string(settings.get_string('energize-a-color'))[1];
 
       // clang-format off
-      this.set_uniform_float(this._uForOpening, 1, [forOpening]);
-      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')]);
+      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
     }
 
@@ -172,7 +170,6 @@ if (utils.isInShellProcess()) {
         ${shaderSnippets.noise()}
         ${shaderSnippets.edgeMask()}
 
-        uniform bool  uForOpening;
         uniform vec3  uColor;
         uniform float uScale;
 
@@ -234,12 +231,12 @@ if (utils.isInShellProcess()) {
 
         // Add molecule particles.
         vec2 uv = scaledUV + vec2(0, 0.1*uTime);
-        uv *= 0.010598 * vec2(0.5*uSizeX, uSizeY);
+        uv *= 0.010598 * vec2(0.5*uSize.x, uSize.y);
         float particles = 0.2 * pow((simplex3D(vec3(uv, 0.0*uTime))), 3.0);
 
         // Add more molecule particles.
         for (int i=1; i<=3;++i) {
-          vec2 uv = scaledUV * 0.12154 / pow(1.5, i) * vec2(uSizeX, uSizeY);
+          vec2 uv = scaledUV * 0.12154 / pow(1.5, i) * uSize;
           float atoms = simplex3D(vec3(uv, 2.0*uTime/i));
           particles += 0.5 * pow(0.2 * (1.0 / (1.0 - atoms)-1.0), 2);
         }
diff --git a/src/EnergizeB.js b/src/EnergizeB.js
index 331f00d..6a4486a 100644
--- a/src/EnergizeB.js
+++ b/src/EnergizeB.js
@@ -140,9 +140,8 @@ if (utils.isInShellProcess()) {
     _init() {
       super._init();
 
-      this._uForOpening = this.get_uniform_location('uForOpening');
-      this._uColor      = this.get_uniform_location('uColor');
-      this._uScale      = this.get_uniform_location('uScale');
+      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
@@ -151,9 +150,8 @@ if (utils.isInShellProcess()) {
       const c = Clutter.Color.from_string(settings.get_string('energize-b-color'))[1];
 
       // clang-format off
-      this.set_uniform_float(this._uForOpening, 1, [forOpening]);
-      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')]);
+      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
     }
 
@@ -172,7 +170,6 @@ if (utils.isInShellProcess()) {
         ${shaderSnippets.noise()}
         ${shaderSnippets.edgeMask()}
 
-        uniform bool  uForOpening;
         uniform vec3  uColor;
         uniform float uScale;
 
@@ -248,21 +245,21 @@ if (utils.isInShellProcess()) {
 
         // Add leading shower particles.
         vec2 showerUV = cogl_tex_coord_in[0].st + vec2(0, -0.7*uProgress/SHOWER_TIME);
-        showerUV *= 0.02 * vec2(uSizeX, uSizeY) / uScale;
+        showerUV *= 0.02 * uSize / uScale;
         float shower = pow(simplex2D(showerUV), 10.0);
         cogl_color_out.rgb += uColor * shower * masks.x;
         cogl_color_out.a += shower * masks.x;
 
         // Add trailing streak lines.
         vec2 streakUV = cogl_tex_coord_in[0].st + vec2(0, -uProgress/SHOWER_TIME);
-        streakUV *= vec2(0.05 * uSizeX, 0.001 * uSizeY) / uScale;
+        streakUV *= vec2(0.05 * uSize.x, 0.001 * uSize.y) / uScale;
         float streaks = simplex2DFractal(streakUV) * 0.5;
         cogl_color_out.rgb += uColor * streaks * masks.y;
         cogl_color_out.a += streaks * masks.y;
 
         // Add glimmering atoms.
         vec2 atomUV = cogl_tex_coord_in[0].st + vec2(0, -0.025*uProgress/SHOWER_TIME);
-        atomUV *= 0.2 * vec2(uSizeX, uSizeY) / uScale;
+        atomUV *= 0.2 * uSize / uScale;
         float atoms = pow((simplex3D(vec3(atomUV, uTime))), 5.0);
         cogl_color_out.rgb += uColor * atoms * masks.z;
         cogl_color_out.a += atoms * masks.z;
diff --git a/src/Fire.js b/src/Fire.js
index 8f8173f..93a65ba 100644
--- a/src/Fire.js
+++ b/src/Fire.js
@@ -259,7 +259,6 @@ if (utils.isInShellProcess()) {
         this.get_uniform_location('uGradient5'),
       ];
 
-      this._uForOpening    = this.get_uniform_location('uForOpening');
       this._u3DNoise       = this.get_uniform_location('u3DNoise');
       this._uScale         = this.get_uniform_location('uScale');
       this._uMovementSpeed = this.get_uniform_location('uMovementSpeed');
@@ -277,7 +276,6 @@ if (utils.isInShellProcess()) {
       }
 
       // clang-format off
-      this.set_uniform_float(this._uForOpening,    1, [forOpening]);
       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')]);
@@ -301,7 +299,6 @@ if (utils.isInShellProcess()) {
         ${shaderSnippets.edgeMask()}
         ${shaderSnippets.compositing()}
 
-        uniform bool  uForOpening;
         uniform bool  u3DNoise;
         uniform float uScale;
         uniform float uMovementSpeed;
@@ -382,7 +379,7 @@ if (utils.isInShellProcess()) {
 
       const code = `
         // Get a noise value which moves vertically in time.
-        vec2 uv = cogl_tex_coord_in[0].st * vec2(uSizeX, uSizeY) / vec2(400, 600) / uScale;
+        vec2 uv = cogl_tex_coord_in[0].st * uSize / vec2(400, 600) / uScale;
         uv.y += uTime * uMovementSpeed;
 
         float noise = u3DNoise ? simplex3DFractal(vec3(uv*4.0, uTime*uMovementSpeed*1.5))
diff --git a/src/Hexagon.js b/src/Hexagon.js
index 34bd360..78f6fa1 100644
--- a/src/Hexagon.js
+++ b/src/Hexagon.js
@@ -144,7 +144,6 @@ if (utils.isInShellProcess()) {
     _init() {
       super._init();
 
-      this._uForOpening       = this.get_uniform_location('uForOpening');
       this._uAdditiveBlending = this.get_uniform_location('uAdditiveBlending');
       this._uSeed             = this.get_uniform_location('uSeed');
       this._uScale            = this.get_uniform_location('uScale');
@@ -166,7 +165,6 @@ if (utils.isInShellProcess()) {
       const testMode = settings.get_boolean('test-mode');
 
       // clang-format off
-      this.set_uniform_float(this._uForOpening,       1, [forOpening]);
       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')]);
@@ -193,7 +191,6 @@ if (utils.isInShellProcess()) {
         ${shaderSnippets.standardUniforms()}
         ${shaderSnippets.noise()}
 
-        uniform bool  uForOpening;
         uniform bool  uAdditiveBlending;
         uniform vec2  uSeed;
         uniform float uScale;
@@ -258,7 +255,7 @@ if (utils.isInShellProcess()) {
         float glowProgress = smoothstep(0, 1, clamp(progress / 0.5, 0, 1));
         float tileProgress = smoothstep(0, 1, clamp((progress - 0.5) / 0.5, 0, 1));
 
-        vec2 texScale = 0.1 * vec2(uSizeX, uSizeY) / uScale;
+        vec2 texScale = 0.1 * uSize / uScale;
         vec4 hex = getHexagons(cogl_tex_coord_in[0].st * texScale);
 
         if (tileProgress > hex.z) {
diff --git a/src/Matrix.js b/src/Matrix.js
index 5aab908..7b5161d 100644
--- a/src/Matrix.js
+++ b/src/Matrix.js
@@ -163,7 +163,6 @@ if (utils.isInShellProcess()) {
           fontData.width, fontData.height, fontData.rowstride);
       }
 
-      this._uForOpening  = this.get_uniform_location('uForOpening');
       this._uFontTexture = this.get_uniform_location('uFontTexture');
       this._uTrailColor  = this.get_uniform_location('uTrailColor');
       this._uTipColor    = this.get_uniform_location('uTipColor');
@@ -179,7 +178,6 @@ if (utils.isInShellProcess()) {
       const c2 = Clutter.Color.from_string(settings.get_string('matrix-tip-color'))[1];
 
       // clang-format off
-      this.set_uniform_float(this._uForOpening, 1, [forOpening]);
       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')]);
@@ -206,7 +204,6 @@ if (utils.isInShellProcess()) {
         ${shaderSnippets.edgeMask()}
         ${shaderSnippets.compositing()}
 
-        uniform bool      uForOpening;
         uniform sampler2D uFontTexture;
         uniform vec3      uTrailColor;
         uniform vec3      uTipColor;
@@ -224,7 +221,7 @@ if (utils.isInShellProcess()) {
 
         // This returns a flickering grid of random letters.
         float getText(vec2 fragCoord) {
-          vec2 pixelCoords = fragCoord * vec2(uSizeX, uSizeY);
+          vec2 pixelCoords = fragCoord * uSize;
           vec2 uv = mod(pixelCoords.xy, uLetterSize)/uLetterSize;
           vec2 block = pixelCoords/uLetterSize - uv;
 
@@ -239,7 +236,7 @@ if (utils.isInShellProcess()) {
         // to one below each drop and to zero above it. This second value is used for fading
         // the window texture. 
         vec2 getRain(vec2 fragCoord) {
-          float column = cogl_tex_coord_in[0].x * uSizeX;
+          float column = cogl_tex_coord_in[0].x * uSize.x;
           column -= mod(column, uLetterSize);
 
           float delay = fract(sin(column)*78.233) * mix(0.0, 1.0, uRandomness);
@@ -248,7 +245,7 @@ if (utils.isInShellProcess()) {
           float distToDrop  = (uProgress*2-delay)*speed - cogl_tex_coord_in[0].y;
           
           float rainAlpha   = distToDrop >= 0 ? exp(-distToDrop/TRAIL_LENGTH) : 0;
-          float windowAlpha = 1 - clamp(uSizeY*distToDrop, 0, FADE_WIDTH) / FADE_WIDTH;
+          float windowAlpha = 1 - clamp(uSize.y*distToDrop, 0, FADE_WIDTH) / FADE_WIDTH;
           
           // Fade at window borders.
           rainAlpha *= getAbsoluteEdgeMask(EDGE_FADE);
diff --git a/src/SnapOfDisintegration.js b/src/SnapOfDisintegration.js
index 45435ec..983b0ed 100644
--- a/src/SnapOfDisintegration.js
+++ b/src/SnapOfDisintegration.js
@@ -159,7 +159,6 @@ if (utils.isInShellProcess()) {
                              dustData.width, dustData.height, dustData.rowstride);
       }
 
-      this._uForOpening  = this.get_uniform_location('uForOpening');
       this._uDustTexture = this.get_uniform_location('uDustTexture');
       this._uDustColor   = this.get_uniform_location('uDustColor');
       this._uSeed        = this.get_uniform_location('uSeed');
@@ -176,10 +175,9 @@ if (utils.isInShellProcess()) {
       const testMode = settings.get_boolean('test-mode');
 
       // clang-format off
-      this.set_uniform_float(this._uForOpening, 1, [forOpening]);
-      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')]);
+      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
     }
 
@@ -198,7 +196,6 @@ if (utils.isInShellProcess()) {
         ${shaderSnippets.noise()}
         ${shaderSnippets.math2D()}
 
-        uniform bool      uForOpening;
         uniform sampler2D uDustTexture;
         uniform vec4      uDustColor;
         uniform vec2      uSeed;
@@ -259,7 +256,7 @@ if (utils.isInShellProcess()) {
         
           // Now check wether there is actually something in the current dust layer at
           // the coords position.
-          vec2 dustCoords = (coords + uSeed) * vec2(uSizeX, uSizeY) / uDustScale / 100.0;
+          vec2 dustCoords = (coords + uSeed) * uSize / uDustScale / 100.0;
           vec2 dustMap    = texture2D(uDustTexture, dustCoords).rg;
           float dustGroup = floor(dustMap.g * DUST_LAYERS * 0.999);
 
diff --git a/src/TRexAttack.js b/src/TRexAttack.js
index b43ddcc..31a4d1f 100644
--- a/src/TRexAttack.js
+++ b/src/TRexAttack.js
@@ -156,7 +156,6 @@ if (utils.isInShellProcess()) {
                              clawData.width, clawData.height, clawData.rowstride);
       }
 
-      this._uForOpening    = this.get_uniform_location('uForOpening');
       this._uClawTexture   = this.get_uniform_location('uClawTexture');
       this._uFlashColor    = this.get_uniform_location('uFlashColor');
       this._uSeed          = this.get_uniform_location('uSeed');
@@ -174,7 +173,6 @@ if (utils.isInShellProcess()) {
       const testMode = settings.get_boolean('test-mode');
 
       // clang-format off
-      this.set_uniform_float(this._uForOpening,    1, [forOpening]);
       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')]);
@@ -199,7 +197,6 @@ if (utils.isInShellProcess()) {
         ${shaderSnippets.compositing()}
 
         // See assets/README.md for how this texture was created.
-        uniform bool      uForOpening;
         uniform sampler2D uClawTexture;
         uniform vec4      uFlashColor;
         uniform vec2      uSeed;
@@ -219,7 +216,7 @@ if (utils.isInShellProcess()) {
 
           // Shift coordinates by a random offset and make sure the have a 1:1 aspect ratio.
           vec2 coords = texCoords + hash22(seed);
-          coords *= uSizeX < uSizeY ? vec2(1.0, 1.0 * uSizeY / uSizeX) : vec2(1.0 * uSizeX / uSizeY, 1.0);
+          coords *= uSize.x < uSize.y ? vec2(1.0, 1.0 * uSize.y / uSize.x) : vec2(1.0 * uSize.x / uSize.y, 1.0);
 
           // Apply global scale.
           coords *= gridScale;
diff --git a/src/TVEffect.js b/src/TVEffect.js
index f6463ef..19eb601 100644
--- a/src/TVEffect.js
+++ b/src/TVEffect.js
@@ -141,19 +141,14 @@ if (utils.isInShellProcess()) {
     _init() {
       super._init();
 
-      this._uForOpening = this.get_uniform_location('uForOpening');
-      this._uColor      = this.get_uniform_location('uColor');
+      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];
-
-      // clang-format off
-      this.set_uniform_float(this._uForOpening, 1, [forOpening]);
-      this.set_uniform_float(this._uColor,      3, [c.red / 255, c.green / 255, c.blue / 255]);
-      // clang-format on
+      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
@@ -169,7 +164,6 @@ if (utils.isInShellProcess()) {
         // Inject some common shader snippets.
         ${shaderSnippets.standardUniforms()}
 
-        uniform bool uForOpening;
         uniform vec3 uColor;
 
         const float BLUR_WIDTH = 0.01; // Width of the gradients.
diff --git a/src/Wisps.js b/src/Wisps.js
index 42b14fa..6d3151e 100644
--- a/src/Wisps.js
+++ b/src/Wisps.js
@@ -141,10 +141,9 @@ if (utils.isInShellProcess()) {
     _init() {
       super._init();
 
-      this._uForOpening = this.get_uniform_location('uForOpening');
-      this._uSeed       = this.get_uniform_location('uSeed');
-      this._uColor      = this.get_uniform_location('uColor');
-      this._uScale      = this.get_uniform_location('uScale');
+      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
@@ -156,10 +155,9 @@ if (utils.isInShellProcess()) {
       const testMode = settings.get_boolean('test-mode');
 
       // clang-format off
-      this.set_uniform_float(this._uForOpening, 1, [forOpening]);
-      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')]);
+      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
     }
 
@@ -179,7 +177,6 @@ if (utils.isInShellProcess()) {
         ${shaderSnippets.edgeMask()}
         ${shaderSnippets.compositing()}
 
-        uniform bool  uForOpening;
         uniform vec2  uSeed;
         uniform vec3  uColor;
         uniform float uScale;
@@ -196,7 +193,7 @@ if (utils.isInShellProcess()) {
         float getWisps(vec2 texCoords, float gridSize, vec2 seed) {
 
           // Shift coordinates by a random offset and make sure the have a 1:1 aspect ratio.
-          vec2 coords = (texCoords + hash22(seed)) * vec2(uSizeX, uSizeY);
+          vec2 coords = (texCoords + hash22(seed)) * uSize;
 
           // Apply global scale.
           coords /= gridSize;
@@ -258,7 +255,7 @@ if (utils.isInShellProcess()) {
         float windowOut = smoothstep(0, 1, clamp(progress/WINDOW_OUT_TIME, 0, 1));
 
         // Use a noise function to dissolve the window.
-        float noise = smoothstep(1.0, 0.0, abs(2.0 * simplex2DFractal(uv * vec2(uSizeX, uSizeY) / 250) - 1.0));
+        float noise = smoothstep(1.0, 0.0, abs(2.0 * simplex2DFractal(uv * uSize / 250) - 1.0));
         float windowMask = 1.0 - (windowOut < 0.5 ? mix(0.0, noise, windowOut * 2.0) : mix(noise, 1.0, windowOut * 2.0 - 1.0));
         cogl_color_out.a *= windowMask * mask;
 
diff --git a/src/shaderSnippets.js b/src/shaderSnippets.js
index 275140e..6178315 100644
--- a/src/shaderSnippets.js
+++ b/src/shaderSnippets.js
@@ -18,18 +18,18 @@
 //////////////////////////////////////////////////////////////////////////////////////////
 
 // These should be included in every shader.
+// uForOpening: True if a window-open animation is ongoing, false otherwise.
 // uTexture:    Contains the texture of the window.
 // uProgress:   A value which transitions from 0 to 1 during the entire animation.
 // uTime:       A steadily increasing value in seconds.
-// uSizeX:      The horizontal size of uTexture in pixels.
-// uSizeY:      The vertical size of uTexture in pixels.
+// uSize:       The size of uTexture in pixels.
 function standardUniforms() {
   return `
+  uniform bool      uForOpening;
   uniform sampler2D uTexture;
   uniform float     uProgress;
   uniform float     uTime;
-  uniform float     uSizeX;
-  uniform float     uSizeY;
+  uniform vec2      uSize;
   `;
 }
 
@@ -78,8 +78,8 @@ function edgeMask() {
   }
 
   float getAbsoluteEdgeMask(float fadePixels) {
-    vec2 uv = cogl_tex_coord_in[0].st * vec2(uSizeX, uSizeY);
-    return getEdgeMask(uv, vec2(uSizeX, uSizeY), fadePixels);
+    vec2 uv = cogl_tex_coord_in[0].st * uSize;
+    return getEdgeMask(uv, uSize, fadePixels);
   }
   
   float getRelativeEdgeMask(float fadeAmount) {