🔧 Tweak glitch effect

resources/shaders/glitch.frag

@@ -15,23 +15,22 @@
 // The content from common.glsl is automatically prepended to each shader effect.
 
 uniform vec3 uColor;
+uniform float uSeed;
 uniform float uScale;
 uniform float uStrength;
 uniform float uSpeed;
 
 // Somewhat inspired by https://www.shadertoy.com/view/XtK3W3
 void main() {
-  float progress = (uForOpening ? 1.0 - uProgress : uProgress);
-  float time     = 7.5 * progress * uDuration * uSpeed;
+  float progress = easeInQuad(uForOpening ? 1.0 - uProgress : uProgress);
+  float time     = progress * uDuration * uSpeed;
   float strength = uStrength * progress;
-  float displace = 750.0 * strength / uSize.x;
-  float yPos     = uScale * uSize.y * iTexCoord.y;
+  float displace = 1000.0 * strength / uSize.x;
+  float yPos     = uScale * uSize.y * (iTexCoord.y + uSeed * 10.0);
 
-  // Create large, incidental noise waves.
-  float noise = clamp(simplex2D(vec2(time, yPos * 0.002)) - 0.3, 0.0, 1.0);
-
-  // Offset by smaller, constant noise waves.
-  noise = noise + (simplex2D(vec2(time * 10.0, yPos * 0.05)) - 0.5) * 0.15;
+  // Create large noise waves and add some smaller noise waves.
+  float noise = clamp(simplex2D(vec2(time, yPos * 0.002)) - 0.5, 0.0, 1.0);
+  noise += (simplex2D(vec2(time * 10.0, yPos * 0.05)) - 0.5) * 0.15;
 
   // Apply the noise as x displacement for every line.
   float xPos  = clamp(iTexCoord.x - displace * noise * noise, 0.0, 1.0);
@@ -42,21 +41,25 @@ void main() {
   float interferenceStrength = noise * min(strength, 1.0);
   oColor.rgb                 = mix(oColor.rgb, interference, interferenceStrength);
 
-  // Apply a line pattern every 4 pixels.
+  // Mix in some grainy noise.
+  vec3 grain          = uColor * simplex2D(uSize * iTexCoord + vec2(time * 100.0));
+  float grainStrength = 0.2 * min(strength, 1.0);
+  oColor.rgb          = mix(oColor.rgb, grain, grainStrength);
+
+  // Add a subtle line pattern every 4 pixels.
   if (floor(mod(yPos * 0.25, 2.0)) == 0.0) {
     oColor.rgb = mix(uColor, oColor.rgb, 1.0 - (0.15 * noise));
   }
 
   // Shift green/blue channels.
-  oColor.g = mix(oColor.g,
-                 getInputColor(vec2(xPos + noise * 0.1 * displace, iTexCoord.y)).g, 0.25);
-  oColor.b = mix(oColor.b,
-                 getInputColor(vec2(xPos - noise * 0.1 * displace, iTexCoord.y)).b, 0.25);
+  float offset = 0.1 * noise * displace;
+  oColor.g     = mix(oColor.g, getInputColor(vec2(xPos + offset, iTexCoord.y)).g, 0.25);
+  oColor.b     = mix(oColor.b, getInputColor(vec2(xPos - offset, iTexCoord.y)).b, 0.25);
 
   // Dissolve the window.
-  if (progress > mix(1.0 - noise, max(max(oColor.r, oColor.g), oColor.b), 0.5)) {
-    oColor.a = 0.0;
-  }
+  float fadeDelay = 2.0;
+  float alpha = clamp(noise + 1.0 + fadeDelay - (3.0 + fadeDelay) * progress, 0.0, 1.0);
+  oColor.a *= alpha;
 
   setOutputColor(oColor);
 }