Easy Patterns

Mirrored stripes with a border

A picture built in steps: mirror left/right, then draw stripes, then color it, then finish with a border. Every step is listed below with its exact numbers.

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The target picture for the shader challenge "Mirrored stripes with a border" — Recreate this picture. You pass at a 99% match, then try to write it in fewer characters than the par.

How this challenge works

You write a fragment shader that draws the picture above, live in your browser. A match bar shows how close you are, and the score combines accuracy, code size (the par is 384 characters in Unity (Built-in)) and GPU speed. Work in HLSL, GLSL, WGSL, Metal or Godot and export the result when you are done.

The numbers you need

Space: p = (uv - 0.5) * float2(aspect, 1.0)
Step 1: Mirror left/right: p.x = abs(p.x)
Step 2: Pattern: m = step(0.35, frac(dot(p, float2(1.0, 0.0)) * 10.0))
Step 3: Colors: lerp(float3(0.14, 0.04, 0.14), float3(0.86, 0.25, 0.85), m)
Step 4: Finish: edge = min(min(uv.x, 1.0 - uv.x), min(uv.y, 1.0 - uv.y)); col = lerp(float3(0.4, 0.5, 0.98), col, smoothstep(0.055, 0.061, edge))

Solve it in your language

Unity (Built-in), Unity (URP), Unreal, Shadertoy / WebGL, OpenGL (LWJGL, raylib), three.js, GameMaker, LÖVE (Lua), Godot, Apple (iOS, macOS), WebGPU / Bevy.

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How this challenge works

The numbers you need

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