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.
Update the sixels' 'row' attribute when re-flowing a grid, to ensure
it is rendered at the correct place.
This should work in most cases, but will break when the cell size has
changed (e.g. font size increase/decrease, or a DPI change).
This patch also moves the sixel image list from the terminal struct
into the grid struct. The sixels are per-grid after all.
