From 0c052ad410ac400b92533e4062d4f8c25cb2c458 Mon Sep 17 00:00:00 2001
From: davidovski <david@davidovski.xyz>
Date: Mon, 1 Dec 2025 10:08:43 +0000
Subject: Add Glitch shade

---
 config/picom/shaders/glitch.glsl | 86 ++++++++++++++++++++++++++++++++++++++++
 1 file changed, 86 insertions(+)
 create mode 100644 config/picom/shaders/glitch.glsl

(limited to 'config/picom/shaders/glitch.glsl')

diff --git a/config/picom/shaders/glitch.glsl b/config/picom/shaders/glitch.glsl
new file mode 100644
index 0000000..be28f78
--- /dev/null
+++ b/config/picom/shaders/glitch.glsl
@@ -0,0 +1,86 @@
+#version 330
+
+
+int delta = 20;
+float barh = 0.02;
+float barw = 0.4;
+int nbar = 16;
+
+float maxoff = 5;
+float minoff = 2;
+
+in vec2 texcoord;             // texture coordinate of the fragment
+
+uniform sampler2D tex;        // texture of the window
+ivec2 window_size = textureSize(tex, 0);
+ivec2 window_center = ivec2(window_size.x/2, window_size.y/2);
+
+// Default window post-processing:
+// 1) invert color
+// 2) opacity / transparency
+// 3) max-brightness clamping
+// 4) rounded corners
+vec4 default_post_processing(vec4 c);
+
+uniform float time; // Time in miliseconds.
+
+float alpha = round(time/delta); // Like time, but in seconds and resets to 
+
+// Pseudo-random function (from original shader)
+float random(float n) {
+    return fract(sin(n) * 43758.5453f);
+}
+
+float get_box() {
+    float n = random(alpha)*(nbar);
+
+    for(int i=0;i<n;i++){
+        float y = random(mod(alpha, 2048)+i) * window_size.y;
+        float x = random(mod(alpha+128, 2048)+i) * window_size.x;
+        float w = random(mod(alpha+64, 2048)+i) * barw*window_size.x;
+        float h = random(mod(alpha+32, 2048)+i) * barh*window_size.y;
+        if (texcoord.y > y && texcoord.y < y + h
+         && texcoord.x > x && texcoord.x < x + w) {
+            return i*w*h*y*x*n;
+        }
+    }
+    return -1.0f;
+}
+
+float rand_offset(float b) {
+    return (random(b*64) - 0.5) * (maxoff*2);
+}
+
+vec4 window_shader() {
+    float b = get_box();
+
+    if (b == -1.0) {
+        vec4 c = texelFetch(tex, ivec2(texcoord), 0);
+        return default_post_processing(c);
+    }
+    //b = random(mod(alpha, 2000));
+
+    // Offsets in pixels for each color
+    vec2 uvr = vec2(rand_offset(b*1), rand_offset(b*6));
+    vec2 uvg = vec2(rand_offset(b*2),rand_offset(b*7));
+    vec2 uvb = vec2(rand_offset(b*3),rand_offset(b*8));
+
+    // Calculate offset coords
+    uvr += texcoord;
+    uvg += texcoord;
+    uvb += texcoord;
+
+    // Fetch colors using offset coords
+    vec3 offset_color;
+    offset_color.x = texelFetch(tex, ivec2(uvr), 0).x;
+    offset_color.y = texelFetch(tex, ivec2(uvg), 0).y;
+    offset_color.z = texelFetch(tex, ivec2(uvb), 0).z;
+    
+    // Set the new color
+    vec4 c;
+    c.w = texelFetch(tex, ivec2(uvr), 0).w;
+    c.xyz = offset_color;
+
+    return default_post_processing(c);
+}
+
-- 
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