static void fillTriangle(BufferedImage image, int x1, int y1, int x2, int y2, int x3, int y3, Color color) {
  Graphics2D g = image.createGraphics();
  g.setColor(color);
  g.fillPolygon(intArray(x1, x2, x3), intArray(y1, y2, y3), 3);
  g.dispose();
}