// In class exercise: working with class; breathing square

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let rectangle = [];

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function setup() {

  createCanvas(400, 400);

​

  for (let i = 0; i < 10; i++) {

    rectangle[i] = new GrowingRect(i + 1);

  }

}

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function draw() {

  background(0);

​

  for (let i = 0; i < 10; i++) {

    rectangle[i].grow();

    rectangle[i].shrink();

    rectangle[i].show();

  }

}

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class GrowingRect {

  constructor(size) {

    this.xPos = width / 2;

    this.yPos = height / 2;

    this.size = size;

    this.changeSize = 1.25;

    this.color = color(255, 255, 255);

  }

​

  grow() {

    this.size += this.changeSize;

    // print(this.size);

  }

  shrink() {

    // when the rectangle fills the whole canvas, it shrinks back to 0

    if (this.size > 400) {

      this.size = -this.size;

    }

  }

​

  show() {

    rectMode(CENTER);

    fill(this.color);

    noStroke();

    rect(this.xPos, this.yPos, this.size);

  }

}

​