sclass CircleWithColor implements RenderableWithHints {
  Pt center;
  int r;
  RGB color;
  
  *() {}
  *(Pt *center, int *r, RGB *color) {}
  *(Pt *center, int *r, Color color) { this.color = new RGB(color); }
  
  public void renderOn(Graphics2D g, int w, int h) {
    fillCircle(g, center.x, center.y, r, toColor(color));
  }
  
  public void renderHints(Graphics2D g, int w, int h) {
    drawCircle(g, center.x, center.y, r, colorWithAlpha(0.5, Color.black));
  }
}