Support larger font sizes.
Submitted by: Dmitry Wagin (original version)
Can use spleen font for testing.
Correct typo (; instead of , in variable definition)
Works on my 2560x1440 screen.
Would it be cleaner if it was a for loop instead?
Slightly awkward because the i-- is at the beginning of the body not the end. I find the implementation of the rshift_row function a little unusual but will commit the submitted / tested version, perhaps rework it later.