`cosmic-term` currently has an issue where borders appear to separate
some cells columnwise. This was caused due to the accumulation of
floating point error when using font sizes that can't be fully
represented in an f32. For example, a font size of 8.4x20 and a unique
color per cell is enough to reproduce this. Essentially, the glyph
background rectangles are being drawn slightly too narrow, causing the
terminal background to leak through. This patch rounds the rectangles in
such a way that we guarantee the drawing of that "border" pixel using
floor() and ceil().
7daf10e3b5