createCanvas(800, 800);

  background(240,211,17);

}

​

function draw() {

  // set color options

  fill(86,66,138);

  noStroke();

  // begin curve

  beginShape();

  // control point

  curveVertex(0, 0);

  // start point

  curveVertex(0, 0);

  // curve midpoints

  curveVertex(100, 100);

  curveVertex(400, 180);

  curveVertex(350, 550);

  curveVertex(650, 540);

  curveVertex(width, height)

  // end points

  curveVertex(width * 2, height * 2);

  curveVertex(width * 2, 0); // end in top right to cover half of canvas

  // control point

  curveVertex(width * 2, 0);

  // end curve

  endShape();

}

​