Scale

/**
 * Scale 
 * by Denis Grutze. 
 * 
 * Paramenters for the scale() function are values specified 
 * as decimal percentages. For example, the method call scale(2.0) 
 * will increase the dimension of the shape by 200 percent. 
 * Objects always scale from the origin. 
 */
 
float a = 0.0;
float s = 0.0;

void setup() {
    size(640, 360);

    noStroke();
    rectMode(CENTER);

    frameRate(30);
}

void draw() {
    background(102);

    a = a + 0.04;
    s = cos(a) * 2;

    translate(width / 2, height / 2);

    scale(s);

    fill(51);
    rect(0, 0, 50, 50);

    translate(75, 0);

    fill(255);

    scale(s);

    rect(0, 0, 50, 50);
}