Drawing hexagons in Processing / Processing で正6角形を描く

hexagons.pde

void setup() {
  size(500, 500);
  for (int i = 0; i < 20; i++) {
    hexagon(random(width), random(height), 20);
  }
}

/** drawing a hexagon inscribed a circle as radius r and its center is placed at (x, y).
 */
void hexagon(float x, float y, float r) {
  pushMatrix();
  translate(x, y);
  scale(1, -1);
  rotate(HALF_PI);
  beginShape();
  for (int i = 0; i < 6; i++) {
    vertex(r * cos(TWO_PI * i / 6), r * sin(TWO_PI * i / 6));
  }
  endShape(CLOSE);
  popMatrix();
}