Font metrics realistically should be integral. Cell widths, cell
heights, etc. do not make sense to be floats, since our grid is
integral. There is no such thing as a "half cell" (or any point).
The reason we historically had these all as f32 is simplicity mixed
with history. OpenGL APIs and shaders all use f32 for their values, we
originally only supported OpenGL, and all the font rendering used to be
directly in the renderer code (like... a year+ ago).
When we refactored the font metrics calculation to its own system and
also added additional renderers like Metal (which use f64, not f32), we
never updated anything. We just kept metrics as f32 and casted
everywhere.
With CoreText and #177 this finally reared its ugly head. By forgetting
a simple rounding on cell metric calculation, our integral renderers
(sprite fonts) were off by 1 pixel compared to the GPU renderers.
Insidious.
Let's represent font metrics with the types that actually make sense: a
cell width/height, etc. is _integral_. When we get to the GPU, we now
cast to floats. We also cast to floats whenever we're doing more precise
math (i.e. mouse offset calculation). In this case, we're only
converting to floats from a integral type which is going to be much
safer and less prone to uncertain rounding than converting to an int
from a float type.
Fixes#177
This fixes or at least is the first step towards #171:
- it adds `cmd/super + return` as the default keybinding to toggle
fullscreen for currently focused window.
- it adds a keybinding handler to the embedded apprt and then changes
the macOS app to handle the keybinding by toggling currently focused
window.
This extends the list of characters we convert to non-printable
characters when control is pressed by adding `backslash`,
`left_bracket`, `right_bracket` to the list.
This is based on the "Legacy `ctrl` mapping of ASCII keys" section in
the Kitty documentation [0]. That page also links to the VT100
documentation [1] that contains Table 3-5, which shows the same mappings
at the Kitty documentation.
I started out wanting to add only `left_bracket` because I very often
use ctrl+[ to escape insert mode in Vim (it maps to escape), but then
added `backslash`, `right_bracket` too because they're next in the list
and having `ctrl+right_bracket` mapped also makes it work in Vim as the
default go-to-def combination.
Why not complete the whole table? Some keys aren't yet handled in
`input.zig`, such as `circumflex` (not defined), and mitchellh said that
it'd require more elaborate handling of different keyboard layouts. So
instead of adding something that might be wrong, I tried to add what I
knew (and tested) to work.
[0]: https://sw.kovidgoyal.net/kitty/keyboard-protocol/#legacy-ctrl-mapping-of-ascii-keys
[1]: https://vt100.net/docs/vt100-ug/chapter3.html
