const xdist = 50;

​

let n = 0.0;

let m = 0.0;

let pts = [];

​

function setup() {

  createCanvas(400, 400);

  stroke(64, 64, 64, 50);

  for (let y=0; y<=height; y+=ydist){

    pts.push([]);

    for (let x=0; x<=width*2; x+=xdist){

      let newy = y + noise(y + (x / 100)) * (height - y * 0.25)

      pts[pts.length-1].push({x:x, y:newy});

    }

  }

  //noLoop();

}

​

function draw() {

  n=frameCount / 100;

  background(220);

  translate(width * -0.5, height * -0.2);

  for (let i=0; i<height; i+=10) {

    fill(map(i, 0, height, 127, 255), map(sin(frameCount/100)*100, -100, 100, 0, 127), 127);

    beginShape();

    curveVertex(0, height*2);

    let inew = floor(i/ydist);

    let ioff = i%ydist;

    //translate(map(mouseX, 0, width, width * -0.05, width * 0.05), 0)

    for (let j=0; j<pts[inew].length; j++) { //

      n += 0.005;

      let xoff = noise(n) * 100;

      if (j < pts[inew].length - 1 && ioff > 0) {

        yoff = lerp(pts[inew][j].y, pts[inew+1][j].y, ioff/ydist);

        curveVertex(pts[inew][j].x + xoff, yoff);

      } else {

        curveVertex(pts[inew][j].x + xoff, pts[inew][j].y);

      }

    }

    curveVertex(width*2, height*2);

    curveVertex(width*2, height*2);

    curveVertex(0, height*2);

    endShape(CLOSE);

  }

}