1-pixel artifact for offscreen pixels (fill_rect bug)

[rdrpenguin04]

When a rectangle is off the left side of the screen, it renders one pixel due to several conflicting rendering optimizations.

[rdrpenguin04]

To clarify (and add more details):

• When the rectangle is off the right/bottom edge of the screen, it is correctly not rendered
• When the rectangle is off the left/top edge of the screen, it gets rendered as one pixel on the far left/top