noise wave (2025)

// make source code public

// schien@mail.ncku.edu.tw, Spring 2025

//

// the baby-step way to draw a line in variations with noise

// program for lectures on "The Wrong Way to Draw a Line"

// schien@mail.ncku.edu.tw, Fall 2018

// revised for DPD 2023

//

​

function setup() {

  createCanvas(500, 100);

  noLoop();

}

​

function draw() {

  background(255);

  strokeWeight(5);

  stroke(0, 30);

  line(20, 50, 480, 50);

  stroke(20, 50, 70, 150); 

  let step = 10; 

  let nlevel = 0.1;

  let lastx = -999; 

  let lasty = -999;

  let ynoise = random(10);

  let y; 

  let border = 20; 

  for (var x=border; x<=width-border; x+=step) { 

    y = 10 + noise(ynoise)*80; 

    if (lastx > -999) { 

      line(x, y, lastx, lasty);

    } 

    lastx = x; 

    lasty = y;

    ynoise += nlevel;

  }

}