IoT Shader Simulator

// Cosmos — fractal palette shader (ShaderToy port)
// Resolution for normalizing pixel coordinates
const res = W;

// Map pixel to [-1, 1] UV space (centered)
let uvx = (px * 2.0 - res) / res;
let uvy = (py * 2.0 - res) / res;
// Save original UV for palette and distance falloff
const uv0x = uvx, uv0y = uvy;
// Accumulated color channels
let fr = 0, fg = 0, fb = 0;

// Distance from center (used for palette + glow falloff)
const len_uv0 = length(uv0x, uv0y);
// Exponential falloff — dims pixels far from center
const e_neg = exp(-len_uv0);

// 4 fractal iterations, each zooming into the pattern
for (let i = 0; i < 4; i++) {
  // Repeat UV space: zoom 1.5x and wrap to [-0.5, 0.5]
  uvx = fract(uvx * 1.5 + 0.5) - 0.5;
  uvy = fract(uvy * 1.5 + 0.5) - 0.5;

// Distance from cell center in this iteration
  const len_uv = length(uvx, uvy);

// Combine cell distance with center falloff
  let d = len_uv * e_neg;
  // Oscillating wave pattern driven by time
  d = sin(d * 8.0 + iTime) / 8.0;
  // Absolute value creates mirrored ridges
  d = abs(d);
  // Invert and sharpen — small d = bright glow
  d = pow(0.01 / (d + 0.0001), 1.2);

// Cosine palette: shifts hue based on distance + iteration + time
  const t = len_uv0 + i * 0.4 + iTime * 0.4;
  const cr = 0.5 + 0.5 * cos(6.28318 * (t + 0.263)); // red channel offset
  const cg = 0.5 + 0.5 * cos(6.28318 * (t + 0.416)); // green channel offset
  const cb = 0.5 + 0.5 * cos(6.28318 * (t + 0.557)); // blue channel offset

// Add this iteration's colored glow to the total
  fr += cr * d;
  fg += cg * d;
  fb += cb * d;
}

// Clamp to [0,1] and scale to 0-255 RGB
return [clamp(fr, 0, 1) * 255, clamp(fg, 0, 1) * 255, clamp(fb, 0, 1) * 255];