AnimalCrossingQR.ColorDialog.IsInNineBox C# (CSharp) Method

        private int? IsInNineBox(int x, int y, int pX, int pY)
        {
            for (int i = 0; i < 3; i++)
                for (int j = 0; j < 3; j++)
                {
                    Rectangle rect = new Rectangle(
                            x + (ColorBoxSize + ColorBoxBorder) * i,
                            y + (ColorBoxSize + ColorBoxBorder) * j,
                            ColorBoxSize,
                            ColorBoxSize);

                    if (IsInRectangle(rect, pX, pY))
                        return 3 * j + i;
                }

            return null;
        }