ncurses on FreeBSD still uses termcap(5) while foot works fine with
xterm-256color sans status line and visible bell. Having more than
one ncurses version installed may break other applications.
Document -Dterminfo=false uses --term=xterm-256color by default
When enabled, man pages are generated and installed, along with
README.md, CHANGELOG.md and LICENSE. This requires ‘scdoc’ as a make
dependency.
When disabled, ‘scdoc’ is no longer required, no man pages will be
built, and no documentation at all is installed.
Defaults to ‘enabled’.
Since the pre-composing functionality is now part of fcft, it makes
little sense to have a compile time option - there's no size benefit
to be had.
Furthermore, virtually all terminal emulators do
pre-composing (alacritty being an exception), this really isn't that
controversial.
Instead of storing combining data per cell, realize that most
combinations are re-occurring and that there's lots of available space
left in the unicode range, and store seen base+combining combinations
chains in a per-terminal array.
When we encounter a combining character, we first try to pre-compose,
like before. If that fails, we then search for the current
base+combining combo in the list of previously seen combinations. If
not found there either, we allocate a new combo and add it to the
list. Regardless, the result is an index into this array. We store
this index, offsetted by COMB_CHARS_LO=0x40000000ul in the cell.
When rendering, we need to check if the cell character is a plain
character, or if it's a composed character (identified by checking if
the cell character is >= COMB_CHARS_LO).
Then we render the grapheme pretty much like before.
We only used utf8proc to try to pre-compose a glyph from a base and
combining character.
We can do this ourselves by using a pre-compiled table of valid
pre-compositions. This table isn't _that_ big, and binary searching it
is fast.
That is, for a very small amount of code, and not too much extra RO
data, we can get rid of the utf8proc dependency.
This feature lets foot combine e.g. "a\u0301" to "á".
We first check if the current character (that we're about to print) is
a combining character, by checking if it's in one of the following
ranges:
* Combining Diacritical Marks (0300–036F), since version 1.0, with
modifications in subsequent versions down to 4.1
* Combining Diacritical Marks Extended (1AB0–1AFF), version 7.0
* Combining Diacritical Marks Supplement (1DC0–1DFF), versions 4.1 to 5.2
* Combining Diacritical Marks for Symbols (20D0–20FF), since version
1.0, with modifications in subsequent versions down to 5.1
* Combining Half Marks (FE20–FE2F), versions 1.0, with modifications
in subsequent versions down to 8.0
If it is, we check if the last cell appears to contain a valid symbol,
and if so, we attempt to compose (combine) the last cell with the
current character, using utf8proc.
If the result is a combined character, we replace the content in the
previous cell with the new, combined character.
Thus, if you select and copy the printed character, you would get
e.g. "\u00e1" instead of "a\u0301".
This feature can be disabled. By default, it is enabled if the
utf8proc library is found, but can be explicitly disabled, or enabled,
with 'meson -Dunicode-combining=disabled|enabled'.
