constructor(c1, c2, c3, x, y, h) {

    this.c1 = c1;

    this.c2 = c2; 

    this.c3 = c3; 

    this.x = x;

    this.y = y;

    this.h = h;

    this.d = 10;

  }

  display() {

    this.setBlockColor(0, this.x, this.y, this.h); 

    this.setBlockColor(this.x, width-this.x, this.y, this.h);

  }

  move() {

    if (this.x > width || this.x < 0) {

      this.d *= -1; 

    } 

    this.x += this.d;

  }

  setBlockColor(min, range, y, h) {

    let x = 0.5;

​

    this.setGradient(min, min + x*range, this.c1, this.c2, y, h);

    this.setGradient(min + x*range, min + range, this.c2, this.c3, y, h);

​

  }

  setGradient(x, w, c1, c2, y, h) {

    for (let i = x; i <= w; i++) {

      let amt = map(i, x, w, 0, 1);

      let c = lerpColor(c1, c2, amt);

      stroke(c);

      line(i, y, i, y + h);

    }

  }

}