Recently I've been trying radically changing my work. Today's challenge: Every hour, on the hour, make my screen worse. Why? Because no one can stop me. And to make things harder, I have to stay on the computer -- I can't just give up and read a book.

I decided to do everything using shaders, a technology that runs directly on a graphics card, so it's very fast.

I applied various shaders to my working Linux environment using 'picom'. As you'll read below, there are a couple limitations to this approach, but overall it was pretty easy to get started. For details on my setup, see the end of the article.

12 noon -- Switch to monochrome, with a blue tint. This is something I've actually done before, to try to ease the pain of a bright monitor on my eyes.

1pm -- Add 20 degree rotation ; wavy

I rotated the screen 20 degrees. Actually, it applies to each window on its own, so the result was... funky. Each individual window looked like the screenshot below.

I gave up on this (too annoying for this early in the day) and tried slow horizontal waves, like you're under the ocean.

The first issue was that typing didn't update the whole screen -- I fixed that by adding the following to picom.conf:

unredir-if-possible = false;
vsync = true;
use-damage = false;

But I hit two problems. Both come from the fact that shaders are applied per-window, and the mouse is not part of a window.

• The mouse is NOT composited. It's not blue, and it stays in one place. If pixels move in the window, the same pixels don't move on the mouse, and you end up not clicking the right place because the mouse doesn't visually get shifted with the window.

I thought about a few workarounds, but they were complicated:

• Drawing a fake mouse and hiding the real one (doesn't work if the fake mouse is its own window, in terms of position)
• Somehow moving the entire screen into a window, with something like virtual desktop or nested X servers.

The second problem: it's really hard to hide the uncomposited mouse.

I decided this was really a bit of a distraction, and I'd just work within the contraint that pixels never moved, so I could live with the default mouse.

2pm - Added an animated "bar" of missing pixels. It slowly scrolls top to bottom. You can also see the vaguely "CRT" effect I added as my final 1pm version.

3pm - Added a "halo"/ghosting using gaussian blur. This one is a bit hard to see in the screenshot.

4pm - Added animated noise effect

5pm - Added grain effect

5pm - Added washed out effect

6pm - add wave, even though the mouse won't line up with what I'm clicking any more.

8pm - add vertical scroll. Sorry, it's really hard to see in this screenshot.

9pm - invert colors, add 20 degree tilt

9:30pm - At this point, I was getting pretty sick to my stomach, so I decided to speed things up... by adding lots of filters really fast, until I couldn't take it. The next one was a 2x2 grid.

And at this point it was unusable, so I called it quits.

A video of what they all look like combined:

Below are my final shaders and config.

# ~/.config/picom/picom.conf
backend = "glx";
glx-use-copysubbuffer-mesa = true;
glx-no-stencil = true;
glx-no-rebind-pixmap = true;

unredir-if-possible = false;
vsync = true;
use-damage = false;

# Default shader for most windows
window-shader-fg = "/home/zachary/.config/picom/horrible.glsl";

// ~/.config/picom/horrible.glsl
#version 330
uniform sampler2D tex;
in vec2 texcoord;
uniform float time;

vec4 default_post_processing(vec4 c);

vec4 window_shader() {
    vec2 texsize = textureSize(tex, 0);
    vec2 coord = texcoord / texsize;

    if (true) {
        // ========================================
        // 2x2 grid - repeat window 4 times
        // ========================================
        coord = fract(coord * 2.0);
    }

    if (true) {
        // ========================================
        // PASS 5: Rotate entire screen 20 degrees
        // ========================================
        float angle = radians(20.0);
        mat2 rotation = mat2(cos(angle), -sin(angle),
                            sin(angle), cos(angle));
        coord = coord - 0.5;  // Center
        coord = rotation * coord;
        coord = coord + 0.5;  // Un-center
    }

    if (true) {
        // ========================================
        // PASS 4: Bad reception scroll with jank
        // ========================================
        float scrollSpeed = 0.00005;
        float scroll = mod(time * scrollSpeed, 1.0);

        // Add jittery jumps
        float jank = step(0.98, fract(time * 2.3)) * 0.1;
        jank += step(0.95, fract(time * 1.7)) * -0.05;

        coord.y = mod(coord.y + scroll + jank, 1.0);
    }

    if (true) {
        // ========================================
        // PASS 2: Underwater wave distortion
        // ========================================
        float waveAmplitude = 0.1;
        float waveFrequency = 10.0;
        float waveSpeed = 0.00015;

        //coord.y += sin(coord.x * waveFrequency + time * waveSpeed) * waveAmplitude;
        coord.x += cos(coord.y * waveFrequency * 0.7 + time * waveSpeed * 0.8) * waveAmplitude * 0.8;
    }

    // Sample the texture with all distortions applied
    vec4 color = texture2D(tex, coord, 0);

    if (true) {
        // ========================================
        // Simple blur effect
        // ========================================
        vec4 blurred = vec4(0.0);
        float blurAmount = 0.01;  // Blur radius in normalized coords

        // Sample surrounding pixels
        for (float x = -2.0; x <= 2.0; x += 1.0) {
            for (float y = -2.0; y <= 2.0; y += 1.0) {
                vec2 offset = vec2(x, y) * blurAmount;
                blurred += texture2D(tex, coord + offset, 0);
            }
        }
        blurred /= 25.0;  // Average of 5x5 samples
        color = ((color * 1) + blurred)/2;
    }

    if (true) {
        // ========================================
        // TV static noise
        // ========================================
        float noise = fract(sin(dot(coord + time * 0.001, vec2(12.9898, 78.233))) * 437589.5453);
        color.rgb = mix(color.rgb, vec3(noise), 0.2);  // 20% noise, adjust to taste
    }

    if (true) {
        // =======================================
        // Pixel-y static noise
        // ========================================
        float noise = fract(sin(dot(coord + fract(time/800) * 100, vec2(12.9898, 78.233))) * 437589.5453);
        color.rgb = mix(color.rgb, vec3(noise), 0.4);  // 20% noise, adjust to taste
    }

    if (true) {
        // ========================================
        // PASS 3: CRT scanlines
        // ========================================
        float scanlineIntensity = 0.15;
        float scanlineCount = 1080.0;  // Adjust for your screen height

        float scanline = sin(coord.y * texsize.y * 3.14159 * 2.0 / (texsize.y / scanlineCount));
        scanline = scanline * 0.5 + 0.5;  // Remap to 0-1
        color.rgb -= scanlineIntensity * (1.0 - scanline);
    }
    if (true) {
        // ========================================
        // Washed out effect
        // ========================================
        color.rgb = mix(color.rgb, vec3(1.0), 0.4);  // Mix 40% white, adjust 0.4 to taste
    }

    if (true) {
        // ========================================
        // PASS 1: Monochrome + blue underwater tint
        // ========================================
        float gray = dot(color.rgb, vec3(0.299, 0.587, 0.114));
        //color.rgb = vec3(gray);

        // Apply blue underwater tint
        color.rgb = vec3(0.4, 0.6, 1.0) * gray;
    }


    if (true) {
        // ========================================
        // Horizontal dead band (scrolling)
        // ========================================
        float bandHeight = 0.05;
        float bandY = mod(time * 0.0001, 1.0);  // Scrolls from top to bottom, loops

        if (abs(coord.y - bandY) < bandHeight / 2.0) {
            color.rgb = vec3(0.0);
        }
    }

    if (true) {
        // Invert colors
        color.rgb = vec3(1., 1., 1.) - color.rgb;
    }

    return default_post_processing(color);
}

My family and I have been playing Curse of the Dark, an "escape-room" style board game. We recently reached the halfway point, where they recommend taking a break--it's supposed to be two 90-minute play sessions (spoiler: we are on month 6).

Included with the box is an answer sheet, which include scratch-off hints. (You might also be familiar with them from lottery tickets.) You scratch off the grey stuff with a penny, and underneath is the hint. I idly wondered if you could do that yourself.

I found several people online repeating this recipe:

• 2 parts silver acrylic paint (I used 5 parts white, 1 part black)
• 1 part dish soap

They recommended 2-4 layers to make it opaque. I gave it a try.

So visually it looked pretty good. But scratchable, not so much. It was hard to get off, and the paper tore when I scratched harder.

Randomona did some experimentation, and had better luck with all types of paint. Turns out it works way better if you add a layer of plastic, such as tape, rather than applying to paint directly to paper or cardstock. This makes sense since the stickers are basically a thin layer of something on tape. And sure enough, when I looked at the 2-3 other tutorials I read, they all said to apply tape first. Whoops!

I would discover this only later, pictures are later in the post

I decided to give "the reveal" a try with small square post-it notes (50x50 mm, about 2x2 inch).

These were okay. But

• not many fit on a page
• post-its aren't very fun to take off
• sometimes I had to use two notes, or you could see through
• my local store doesn't sell the full-sticky post-its, so you can peek if you really wanted. (I'm not sure if they still make full-sticky, and I don't think they ever did in mini size)

By the way, you can print your own using my bad generator. If you want less than 15, just leave some boxes blank and don't cover them with a post-it.

Next up, I bought some! They sell premade scratch-off stickers. They are available in 50x50 mm, but I went half that size--I'd rather have more on a page.

Mine came in a roll of 1000 stickers for $10 (that's 1 cent per sticker). You can get circles or squares--I picked squares.

Here you can see my scratch-off chores card. It was a lot more fun. I wrote a better second generator you can use to print your own. Up to 88 can fit on a page, and it will shrink the grid if you have less.

Finally, I tried the homemade acrylic paint method a try, with tape this time.

I'd say the stickers scratch off best, followed by the recipe mentioned on tape. I tried more dish soap and no dish soap, and they were both worse. I suspect less dish soap would work better.

You can write on the stickers fine, or the acrylic, but the dish soap recipes scratch off if you try to use a pen on top.