Rotate_180 error

[trancio]

Hi,

I have a rotated max7219 display but rotate_180 = True does not work. The solution written at "Inverted display" was not good for me.

But it works for me:

offset = 8 * self.cols - row * (8 - line) * self.cols
index = (7 - line) * self.cols + col - offset