createCanvas(600, 400);

}

​

function draw() {

    background(220);

​

    //red fill and noStroke

    fill(255, 0, 0);

    noStroke();

​

    print(mouseX);

​

​

    if (mouseX > width / 3 * 2) {

        rect(width / 3 * 2, 0, width / 3, height);

    } else if (mouseX > width / 3) {

        rect(width / 3, 0, width / 3, height);

    } else if (mouseX > 0 && mouseX < width / 3) {

        rect(0, 0, width / 3, height);

    }

}