public void DrawRect(int x, int y, int w, int h)
{
DrawLine(x, y, x, y + h); // Left, vertical line
DrawLine(x + w - 1, y, x + w - 1, y + h); // Right, vertical line
DrawLine(x, y, x + w, y); // Top, horizontal line
DrawLine(x, y + h - 1, x + w, y + h - 1); // Bottom, horizontal line
}