For performance reasons, we track whether a cell is selected or not
using a bit in a cell's attributes.
This makes it easy for the renderer to determine if the cells should
be rendered as selected or not - it just have to look at the
'selected' bit instead of doing a complex range check against the
current selection.
This works nicely in most cases. But, if the cell is updated, the
'selected' bit is cleared. This results in the renderer rendering the
cell normally, i.e. _not_ selected.
Checking for this, and re-setting the 'selected' bit when the cell is
updated (printed to) is way too expensive as it is in the hot path.
Instead, sync the 'selected' bits just before rendering. This isn't so
bad as it may sound; if there is no selection this is a no-op. Even if
there is a selection, only those cells whose 'selected' bit have been
cleared are dirtied (and thus re-rendered) - these cells would have
been re-rendered anyway.
When the client is capturing the mouse, selection can only be done by
holding done shift.
This is why a lot of selection functions are no-ops if selection isn't
currently enabled.
However, there are many cases where we actually need to modify the
selection. In particular, selection_cancel().
Thus, only check for enabled selection when we're dealing with user
input.
Bonus: this also fixes a bug where an ongoing selection were finalized
as soon as the user released shift, even if he was still holding down
the mouse button.
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.
This means command line parsing stops when it encounters the first
nonoption argument.
The result is that one no longer need to use '--' to ensure arguments
are passed to the shell/command, instead of parsed by foot.
That is, instead of
foot -- sh -c true
one can now do
foot sh -c true
Arguments to foot *must* go before the command:
foot --fullscreen sh -c true
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.
Use four threads to load the four primary font variants - normal,
bold, italic and bold italic.
This speeds up initial startup, and reloading of fonts on a DPI
change.
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'.
A lot of the escape sequences on the "CSI Ps ; Ps ; Ps t" form are
expected to return a reply. Thus, not having these implemented means
we will hang if the client sends these escapes.
Not all of these escapes can be meaningfully implemented on Wayland,
and thus this implementation is best effort.
We now support the following escapes:
* 11t - report if window is iconified (always replies "no")
* 13t - report window position (always replies 0,0)
* 13;2t - report text area position (replies with margins, since we
cannot get the window's position)
* 14t - report text area size, in pixels
* 14;2t - report window size, in pixels
* 15t - report screen size, in pixels
* 16t - report cell size, in pixels
* 18t - report text area size, in cells
* 19t - report screen size, in cells
In reset, we allocated new rows for all the currently visible
lines. We did **not** however, free the 'old' rows.
Fix by not explicitly allocating new rows, but instead allocating
uninitialized rows when needed, and then explicitly erasing the row.
If there already was a row allocated, it is simply erased. If there
wasn't, the a new line is malloc:ed, and then erased.
Before, we converted each axis event's scroll amount to an integer and
scrolled that many lines.
However, axis events are speed sensitive - very slow scrolling will
result in events with a scroll amount that is < 1.0.
For us, this meant we never scrolled a single line. You could slow
scroll all day if you wanted, and still we would never scroll a single
line.
Fix this by aggregating the scroll amount from axis events until the
scroll amount is > 1.0, and then scroll.
When resizing in alt mode, we never updated the saved 'normal'
cursor. This meant that when we exited alt mode, the cursor would be
positioned where it was in the old pre-resize/reflow grid.
Now, we update the saved cursor in the same way we update visible
cursor. The result is that when we exit the alt screen, the cursor
is restored to the same coordinates it would have been updated to had
the resize been done in the 'normal' screen.
This fixes an issue where an 'underline' cursor wasn't visible on
underlined text - the cursor was rendered first, and then shadowed by
the text underline.
This fixes an issue where we failed to restore the cursor correctly
when exiting from the alternate screen, if the client had sent escapes
to save the cursor position while inside the alternate screen.
This was because we used the *same* storage for saving the cursor
position through escapes, as for saving it when entering the alternate
screen.
Fix by using a custom variable dedicated to normal <--> alt screen
switching.
