Previous implementation would draw dashes to the edge of the character
cell, which would result in double-wide dashes at the point where they
tiled. This fixes that, and also generally implements it in a cleaner
way than before.
Some box codepoints (the cursor) want to use the original font metrics
height but others (corners) want to use the full grid height. I can't
see a better way to do this than manually maintaining a switch here. We
can add codepoints as needed.
Fixes#757
The x/y is unsigned (as it should be, since top-left is 0,0). In the
case of a very small grid size and certain thickness settings, its
possible to overflow. In this scenario, the only reasonable thing to do
is just clamp to 0 because some sprites are going to look weird with
small enough grids anyways.
Fixes#143
There were multiple issues with the previous calculation. First, we
expected dash width COULD be negative and protected against it, but our
dash width calculation type was unsigned! With the proper font metrics,
this led to an underflow safey panic.
Second, as part of the dash width calculation, we are tryign to downstep
the size of the gaps so we can try to fit dashes within a cell. But we
were not using those adjusted gap sizes. With the proper font metrics,
this could lead to an assertion failure seen in #143.
This fixes the calculations. They produce the same numbers, but do so in
a more Zig-idiomatic way while fixing the above two issues.
