public void Draw(Graphics graphics, Point mouse, Field selectedColour)
{
// Draw it to a bitmap
adjustToNumberSizes();
int squareSize = this.CalculateSquareSize();
Point hover = PuzzleBoard.Mouse2Point(mouse, squareSize, this);
Bitmap bmp = this.drawToBitmap(squareSize, hover, selectedColour, true, Settings.Get.DarkerBackground);
// Draw that bitmap to form
graphics.DrawImage(bmp, this.Offset);
}