Moire patterns

let N = 0;

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function setup() {

  createCanvas(500, 500);

}

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function draw() {

  background(225);

  translate(width / 2, height / 2);

  scale(20);

​

  drawParametric();

  composition();

​

  let t = millis() / 1000;

  N = (1 / 2) * (2 * cos(t + PI) + 2);

}

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function trig(x, y) {

  let u = (x - PI * y) / exp(1);

  let v = (y - PI * x) / exp(1);

  return sin(x) * sin(y) + sin(u) * cos(v);

}

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function drawParametric() {

  noFill();

  strokeWeight(0.05);

  beginShape();

  for (let t = 0; t < 1; t += 0.0001) {

    let angle = 150 * PI * t;

    let x = 10 * t * cos(angle);

    let y = 10 * t * sin(angle);

    vertex(x, y);

  }

  endShape();

}

​

function composition() {

  noFill();

  strokeWeight(0.05);

  beginShape();

  for (let t = 0; t < 1; t += 0.00005) {

    let angle = 150 * PI * t;

    let xBase = 10 * t * cos(angle);

    let yBase = 10 * t * sin(angle);

    let x = funcX(xBase, yBase);

    let y = funcY(xBase, yBase);

    vertex(x, y);

  }

  endShape();

}

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function funcX(x, y) {

  let magnitude = sqrt(x * x + y * y);

  let value = (N * trig(x, y) + magnitude) / magnitude;

  return value * x;

}

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function funcY(x, y) {

  let magnitude = sqrt(x * x + y * y);

  let value = (N * trig(x, y) + magnitude) / magnitude;

  return value * y;

}

​