add anti-flashbang with shader

dots/.config/quickshell/ii/services/hyprlandAntiFlashbangShader/anti-flashbang.glsl

@@ -0,0 +1,47 @@
+#version 300 es
+precision highp float;
+
+in vec2 v_texcoord;
+uniform sampler2D tex;
+out vec4 fragColor;
+
+float overlayOpacityForBrightness(float x) {
+    // Note: range 0 to 1
+    
+    // Will a fancy curve help?... I'll have to experiment more at night
+    // float y = pow(x, 2.0) * 0.75;
+    // float y = (1.0 - exp(-x))*1.15;
+    // float y = (1.0 - exp(-pow((x-0.15), 0.6)))*1.18;
+    float y = x*0.75;
+
+    return min(max(y, 0.001), 1.0);
+}
+
+void main() {
+    // 1. Get the current pixel color
+    vec4 pixColor = texture(tex, v_texcoord);
+
+    // 2. Calculate average screen brightness
+    vec3 totalRGB = vec3(0.0);
+    float samples = 0.0;
+    
+    // We use a nested loop to create a 10x10 grid (100 samples)
+    // This is dense enough to catch small icons/text but light enough to run fast.
+    for(float x = 0.05; x < 1.0; x += 0.1) {
+        for(float y = 0.05; y < 1.0; y += 0.1) {
+            totalRGB += texture(tex, vec2(x, y)).rgb;
+            samples++;
+        }
+    }
+    
+    vec3 avgColor = totalRGB / samples;
+    float globalBrightness = dot(avgColor, vec3(0.2126, 0.7152, 0.0722));
+
+    // 3. Get the specific opacity for this brightness level
+    float opacity = overlayOpacityForBrightness(globalBrightness);
+
+    // 4. Apply the "black overlay" effect
+    vec3 outColor = mix(pixColor.rgb, vec3(0.0), opacity);
+
+    fragColor = vec4(outColor, pixColor.a);
+}