Recreating computer graphics and art

This homework assignment was very challenging for me. I used a source from open processing to do this, but the code was not working, so I had to go through it and learn what needs to change and be added to make it function. The difference with the original is that when the mouse clicks (mousePressed () ) on it, the direction of the lines change by rotating randomly at 0, 120, and 240 degrees.

int width = 600;
int height = 700;
int _size = 20;     // hexagon radius

void setup() {
  
  size(600,700);
  noLoop();
  
  background(25, 150, 180, 20);
  noFill();
  stroke(0);
  strokeWeight(2);

}

void draw() {

  // clear background
  background(25, 150, 170, 20);
  
  // line length (hypotenuse)
  float h = sin(THIRD_PI) * _size;
  
  for (int i = 0; i <= width / (_size * 3); i++) {
    for (int j = 0; j <= (height / h) + 1; j++) {

      // reference points (centre of each hexagon)
      float x = i * _size * 3 + (_size / 2);
      float y = j * h;
      // offset each odd row
      if (j % 2 > 0) {
        x += _size * 1.5;
      }

      pushMatrix();
      
        translate(x, y);
        
        // random hexagon rotation (0, 120, 240 degrees)
        rotate(int(random(0, 3)) * THIRD_PI);
    
        // draw line
        line(0, -h, 0, h);
  
        // draw arcs
        arc(-_size, 0, _size, _size, -THIRD_PI,     THIRD_PI);
        arc( _size, 0, _size, _size,  THIRD_PI * 2, THIRD_PI * 4); 
      popMatrix();}
  }
}
      void mousePressed() {
  
  redraw();
  }