We do this by characterizing the shared bounding boxes in a static copy
of the symbols only nerd font when we're doing the codegen. This allows
us to get results of our scaling that are just as good as in a patched
font, since related glyphs can now be sized and positioned relative to
each other.
Icons were often WAY too big before because they were filling the whole
cell in height, which isn't great lol. This commit adds an `icon_height`
metric which is used to constrain glyphs that shouldn't be the size of
the entire cell.
The nerd font patcher uses `ypadding` as a single subtraction from the
cell height, which means that half of it should go to the top padding
and the other half to the bottom, this was making the heavy brackets way
too small lol (0.4 of the cell height instead of 0.7)
This mostly applies to powerline glyphs, but is also relevant for heavy
bracket characters, which need to always be 1 wide otherwise they look
silly because they misalign depending on if there's a space after them
or not.
Previously `ypadding` was effectively ignored, since it's mutually
exclusive with `overlap`. This had a noticeable effect on the heavy
bracket characters U+276C...U+2771, which were much taller than they
should have been.
I also fixed the vertical overlap limit, since negative `overlap` values
are used in the nerd font attributes to create padding on all sides of
the cell, so we don't want to limit the magnitude of the overlap for
vertical padding, we only want to limit it if the value is positive.
That change fixed the vertical padding for a handful of ranges, which
should give more consistent results.
