At first, an OSC-8 URI range was added when we received the closing
OSC-8 escape (i.e. with an empty URI).
But, this meant that cursor movements while the OSC-8 escape was in
effect wasn’t handled correctly, since we’d add a range that spanned
the cursor movements.
Attempts were made to handle this in the cursor movement functions, by
closing and re-opening the URI.
However, there are too many corner cases to make this a viable
approach. Scrolling is one such example, line-wrapping another.
This patch takes a different approach; emit, or update the URI range
when we print to the grid. This models the intended behavior much more
closely, where an active OSC-8 URI act like any other SGR attribute -
it is applied to all cells printed to, but otherwise have no effect.
To avoid killing performance, this is only done in the “generic”
printer. This means OSC-8 open/close calls must now “switch” the ASCII
printer.
Note that the “fast” printer still needs to *erase* pre-existing OSC-8
URIs.
Closes#816
Each cell now tracks it’s current color source:
* default fg/bg
* base16 fg/bg (maps to *both* the regular and bright colors)
* base256 fg/bg
* RGB
Note that we don’t have enough bits to separate the regular from the
bright colors. These _shouldn’t_ be the same, so we ought to be
fine...
Similar to modifyOtherKeys=1 (foot’s default, and only, mode), except
that:
* All modifiers (and not just Ctrl) generate \E[27;m;n~ escapes
* Regular keys (with modifiers) also generate \E[27;m;n~ escapes (for
example, C-h no longer generates ^H, but \E[27;5;104~)
For our keymap based lookups, this is handled by adding
MOD_MODIFY_OTHER_KEYS_STATE<N> variants.
For “generic” keys, we simply adjust the conditions for when to emit a
\E[27;m;n~ escape - the only requirement is that at least one modifier
is active.
This is an application of the xdg activation protocol that will allow
compositors to associate new foot toplevels with the command that
launched them.
footclient receives an activation token from the launcher which the
compositor can use to track application startup. It passes the token
to the foot server, which then activates the new window with the token
to complete the startup sequence.
With dpi-aware=auto (the default), scale fonts using DPI *only*
if *all* available monitors have a scaling factor of one.
The idea is this: if a user, with multiple monitors, have enabled
scaling on *at least* one monitor, he/she has most likely done so to
match the size of his/hers other monitors.
For example, if the user has one monitor with a scaling factor of one,
and another one with a scaling factor of two, he/she expects things to
be twice as large on the second monitor.
If we (foot) scale using DPI on the first monitor, and using the
scaling factor on the second monitor, foot will *not* look twice as
big on the second monitor (this was the old behavior of
dpi-aware=auto).
Part of #714
The box_drawings array is now quite large, and uses up ~4K
when *empty*.
This patch splits it up into three separate, dynamically allocated
arrays; one for the traditional box+line drawing and block elements
glyphs, one for braille, and one for the legacy computing symbols.
When we need to render a glyph, the *entire* array (that it belongs
to) is allocated.
I.e this is one step closer to a dynamic glyph cache (like the one
fcft uses), but doesn’t go all the way.
This is especially nice for people with
‘box-drawings-uses-font-glyphs=yes’; for them, the custom glyphs now
uses 3*8 bytes (for the three array pointers), instead of 4K.
Render braille ourselves, instead of using font glyphs. Decoding a
braille character is easy enough; there are 256 codepoints,
represented by an 8-bit integer (i.e. subtract the Unicode codepoint
offset, 0x2800, and you’re left with an integer in the range 0-255).
Each bit corresponds to a dot. The first 6 bits represent the upper 6
dots, while the two last bits represent the fourth (and last) row of
dots.
The hard part is sizing the dots and the spacing between them.
The aim is to have the spacing between the dots be the same size as
the dots themselves, and to have the margins on each side be half the
size of the dots.
In a perfectly sized cell, this means two braille characters next to
each other will be evenly spaced.
This is however almost never the case. The layout logic currently:
* Set dot size to either the width / 4, or height / 8, depending on
which one is smallest.
* Horizontal spacing is initialized to the width / 4
* Vertical spacing is initialized to the height / 8
* Horizontal margins are initialized to the horizontal spacing / 2
* Vertical margins are initialized to the vertical spacing / 2.
Next, we calculate the number of “remaining” pixels. That is, if we
add the left margin, two dots and the spacing between, how many pixels
are left on the horizontal axis?
These pixels are distributed in the following order (we “stop” as soon
as we run out of pixels):
* If the dot size is 0 (happens for very small font sizes), increase
it to 1.
* If the margins are 0, increase them to 1.
* If we have enough pixels (need at 2 horizontal and 4 vertical),
increase the dot size.
* Increase spacing.
* Increase margins.
Closes#702
Instead, do the palette lookup when we receive the DECGCI (i.e. when
the palette entry is selected), and store the actual color value in
our sixel struct.
We have all information we need to calculate the default background
color in sixel_init():
* Whether the image have transparency or not
* The current ANSI background color
When updating the selection (i.e when changing it - adding or removing
cells to the selection), we need to do two things:
* Unset the ‘selected’ bit on all cells that are no longer selected.
* Set the ‘selected’ bit on all cells that *are* selected.
Since it’s quite tricky to calculate the difference between the “old”
and “new” selection, this is done by first un-selecting the old
selection, and then selecting the new, updated selection. I.e. first
we clear the ‘selected’ bit from *all* cells, and then we re-set it on
those cells that are still selected.
This process also dirties the cells, to make sure they are
re-rendered (needed to reflect their new selected/un-selected status).
To avoid dirtying *all* previously selected, and newly selected cells,
we have used an algorithm that first runs a “pre-pass”, marking all
cells that *will* be selected as such. The un-select pass would then
skip (no dirty) cells that have been marked by the pre-pass. Finally,
the select pass would only dirty cells that have *not* been marked by
the pre-pass.
In short, we only dirty cells whose selection state have *changed*.
To do this, we used a second ‘selected’ bit in the cell attribute
struct.
Those bits are *scarce*.
This patch implements an alternative algorithm, that frees up one of
the two ‘selected’ bits.
This is done by lazy allocating a bitmask for the entire grid. The
pre-pass sets bits in the bitmask. Thus, after the pre-pass, the
bitmask has set bits for all cells that *will* be selected.
The un-select pass simply skips cells with a one-bit in the
bitmask. Cells without a one-bit in the bitmask are dirtied, and their
‘selected’ bit is cleared.
The select-pass doesn’t even have to look at the bitmask - if the cell
already has its ‘selected’ bit set, it does nothing. Otherwise it sets
it and dirties the cell.
The bitmask is implemented as an array of arrays of 64-bit
integers. Each outer element represents one row. These pointers are
calloc():ed before starting the pre-pass.
The pre-pass allocates the inner arrays on demand.
The unselect pass is designed to handle both the complete absence of a
bitmask, as well as row entries being NULL (both means the cell
is *not* pre-marked, and will thus be dirtied).
Before this patch, pt-or-px values, like letter-spacing, were *always*
scaled using the current DPI value.
This is wrong; if the fonts are scaled using the output’s scaling
factor, then so should all other point values.
This also fixes an issue where e.g. letter-spacing would use one DPI
value at startup, but then when increasing/decreasing or resetting the
font size, would be re-calculated using a different DPI value, leading
to completely different spacing.
This happened when there were multiple monitors, with different DPI
values, and foot guessed the initial DPI value wrong. Normally, foot
would correct itself as soon as the window was mapped, and the
“correct” DPI value known. But if the fonts were scaled using the
scaling factor, it was possible that the font reload never happened.
This patch also updates the thickness calculation (for LIGHT and HEAVY
box drawing characters) to use the scaling factor when appropriate.
Closes#680
When the foot window is closed, and we need to terminate the client application,
do this in an asynchronous fashion:
* Don’t do a blocking call to waitpid(), instead, rely on the reaper callback
* Use a timer FD to implement the timeout before sending SIGKILL (instead of
using SIGALRM).
* Send SIGTERM immediately (we used to *just* close the PTY, and then wait 2
seconds before sending SIGTERM).
* Raise the timeout from 2 seconds to 60
Full shutdown now depends on *two* asynchronous tasks - unmapping the window,
and waiting for the client application to terminate.
Only when *both* of these have completed do we proceed and call term_destroy(),
and the user provided shutdown callback.
This breaks out the scrollback erasing logic for \E[3J from csi.c, and
moves it to the new function term_erase_scrollback(), and changes the
logic to calculate the start and end row (absolute) numbers of the
scrollback, and only iterate those, instead of iterating *all* rows,
filtering out those that are on-screen.
It also adds an intersection range check of the selection range, and
cancels the selection if it touches any of the deleted scrollback
rows.
This fixes a crash when trying to render the next frame, since the
selection now references rows that have been freed.
Closes#633
Up until now, *all* buffers have been tracked in a single, global
buffer list. We've used 'cookies' to separate buffers from different
contexts (so that shm_get_buffer() doesn't try to re-use e.g. a
search-box buffer for the main grid).
This patch refactors this, and completely removes the global
list.
Instead of cookies, we now use 'chains'. A chain tracks both the
properties to apply to newly created buffers (scrollable, number of
pixman instances to instantiate etc), as well as the instantiated
buffers themselves.
This means there's strictly speaking not much use for shm_fini()
anymore, since its up to the chain owner to call shm_chain_free(),
which will also purge all buffers.
However, since purging a buffer may be deferred, if the buffer is
owned by the compositor at the time of the call to shm_purge() or
shm_chain_free(), we still keep a global 'deferred' list, on to which
deferred buffers are pushed. shm_fini() iterates this list and
destroys the buffers _even_ if they are still owned by the
compositor. This only happens at program termination, and not when
destroying a terminal instance. I.e. closing a window in a “foot
--server” does *not* trigger this.
Each terminal instatiates a number of chains, and these chains are
destroyed when the terminal instance is destroyed. Note that some
buffers may be put on the deferred list, as mentioned above.
This patch adds a `confined` flag to each cell to track if the last
rendered glyph bled into it's right neighbor. To keep things simple,
bleeding into any other neighbor cell than the immediate right one is
not allowed. This should cover most use cases.
Before rendering a row we now do a prepass and mark all cells unclean
that are affected by a bleeding neighbor. If there are consecutive
bleeding cells, the whole group must be re-rendered even if only a
single cell has changed.
The patch also deprecates both old overflowing glyph options
*allow-overflowing-double-width-glyphs* and *pua-double-width* in favor
of a single new one named *overflowing-glyphs*.
There has been some confusion whether enabling DECSDM (private mode
80) enables or disables sixel scrolling.
Foot currently enables scrolling when DECSDM is set, and this patch
changes this, such that setting DECSDM now *disables* scrolling.
The confusion is apparently due to a documentation error in the VT340
manual, as described in
https://github.com/dankamongmen/notcurses/issues/1782#issuecomment-863603641.
And that makes sense, in a way: the SDM in DECSDM stands for Sixel
Display Mode. I.e. it stands to reason that enabling that disables
scrolling.
Anyway, this lead to https://github.com/hackerb9/lsix/issues/41, where
it was eventually proven (by testing on a real VT340), that foot, and
a large number of other terminals (including XTerm) has it wrong:
https://github.com/hackerb9/lsix/issues/41#issuecomment-873269599.
Removing overlaping and duplicated URLs is done by running two nested
loops, that both iterate the same URL list.
When a duplicate is found, one of the URLs is destroyed and removed
from the list.
Deleting and removing an item *is* safe, but only as long as _no
other_ iterator has references to it.
In this case, if we remove an item from e.g. the inner iterator, we’ll
crash if the outer iterator’s *next* item is the item being removed.
Closes#627
The previous implementation stored compose chains in a dynamically
allocated array. Adding a chain was easy: resize the array and append
the new chain at the end. Looking up a compose chain given a compose
chain key/index was also easy: just index into the array.
However, searching for a pre-existing chain given a codepoint sequence
was very slow. Since the array wasn’t sorted, we typically had to scan
through the entire array, just to realize that there is no
pre-existing chain, and that we need to add a new one.
Since this happens for *each* codepoint in a grapheme cluster, things
quickly became really slow.
Things were ok:ish as long as the compose chain struct was small, as
that made it possible to hold all the chains in the cache. Once the
number of chains reached a certain point, or when we were forced to
bump maximum number of allowed codepoints in a chain, we started
thrashing the cache and things got much much worse.
So what can we do?
We can’t sort the array, because
a) that would invalidate all existing chain keys in the grid (and
iterating the entire scrollback and updating compose keys is *not* an
option).
b) inserting a chain becomes slow as we need to first find _where_ to
insert it, and then memmove() the rest of the array.
This patch uses a binary search tree to store the chains instead of a
simple array.
The tree is sorted on a “key”, which is the XOR of all codepoints,
truncated to the CELL_COMB_CHARS_HI-CELL_COMB_CHARS_LO range.
The grid now stores CELL_COMB_CHARS_LO+key, instead of
CELL_COMB_CHARS_LO+index.
Since the key is truncated, collisions may occur. This is handled by
incrementing the key by 1.
Lookup is of course slower than before, O(log n) instead of
O(1).
Insertion is slightly slower as well: technically it’s O(log n)
instead of O(1). However, we also need to take into account the
re-allocating the array will occasionally force a full copy of the
array when it cannot simply be growed.
But finding a pre-existing chain is now *much* faster: O(log n)
instead of O(n). In most cases, the first lookup will either
succeed (return a true match), or fail (return NULL). However, since
key collisions are possible, it may also return false matches. This
means we need to verify the contents of the chain before deciding to
use it instead of inserting a new chain. But remember that this
comparison was being done for each and every chain in the previous
implementation.
With lookups being much faster, and in particular, no longer requiring
us to check the chain contents for every singlec chain, we can now use
a dynamically allocated ‘chars’ array in the chain. This was
previously a hardcoded array of 10 chars.
Using a dynamic allocated array means looking in the array is slower,
since we now need two loads: one to load the pointer, and a second to
load _from_ the pointer.
As a result, the base size of a compose chain (i.e. an “empty” chain)
has now been reduced from 48 bytes to 32. A chain with two codepoints
is 40 bytes. This means we have up to 4 codepoints while still using
less, or the same amount, of memory as before.
Furthermore, the Unicode random test (i.e. write random “unicode”
chars) is now **faster** than current master (i.e. before text-shaping
support was added), **with** test-shaping enabled. With text-shaping
disabled, we’re _even_ faster.
Before the grapheme cluster segmentation work, we limited the number
of combining characters to base+5. I.e. 6 in total.
For a while now, we’ve had it bumped all the way up to 20. This was
the reason the unicode-random benchmark ran so much slower (i.e. cache
contention).
Looking at emoji’s, there are a couple that need 6 code points,
and *three* that needs 7.
Now, with the limit at 7 chars, and the new ‘width’ member, the
composed struct is 8 bytes larger than before.
Using the frame callback works most of the time, but e.g. Sway doesn’t
call it while the window is hidden, and thus prevents us from updating
the title in e.g. stacked views.
This patch uses a timer FD instead. We store a timestamp from when the
title was last updated. When the application wants to update the
title, we first check if we already have a timer running, and if so,
does nothing.
If no timer is running, check the timestamp. If enough time has
passed, update the title immediately.
If not, instantiate a timer and wait for it to trigger.
Set the minimum time between two updates to ~8ms (twice per frame, for
a 60Hz output, and ~once per frame on a 120Hz output).
Closes#591
This commit also renames the term_set_single_shift_ascii_printer()
function to term_single_shift(), since the former is overly verbose
and not really even accurate.
These sequences are supposed to affect the next printable ASCII
character and then reset to the previous character set, but before
this commit they were behaving like locking shifts.
echo -e '\e]8;;https://www.foo.bar\e\\https://www.foo\e]8;;\e\\.bar'
will produce an OSC-8 URL (https://www.foo) that is slightly shorter
than the auto-detected one (https://www.foo.bar).
This produces strange results in URL mode. For example, if
url.osc8-underline=always, the OSC8 underline will be removed when
url-mode is exited.
This patch changes the behavior so that auto-detected URLs that
overlap OSC-8 URLs are removed.
Note that OSC-8 URLs cannot overlap with each other, and that
auto-detected URLs also cannot overlap with each other.
We only needed term->font_scale to be able to detect scaling factor
changes (term->font_scale != term->scale).
But, we already have the old scaling factor in all places where
term_font_dpi_changed() is called, so let’s pass the old scaling
factor as an argument instead.
get_font_scale() was used to get the new scaling factor when loading
fonts. This was then compared to the last seen font scaling factor. If
there was no difference, the fonts were not reloaded.
The problem was, the initial term->scale was set differently. This
sometimes led to term->scale=2, while get_font_scale() return 1. That
meant, fonts were initially scaled by 2 (when dpi-aware=no). Later,
when mapped on an output (and thus term->scale being set to 1), the
fonts weren’t reloaded with the correct scaling factor since the
cached term->font_scale value was already 1.
Since term->scale always reflects the *new* scaling factor when
term_font_dpi_changed() is called, use that directly, and remove
get_font_scale().
Also rename the following functions:
* font_should_size_by_dpi() -> font_size_by_dpi_for_scale()
* font_size_by_dpi() -> font_sized_by_dpi()
* font_size_by_scale() -> font_sized_by_scale()
Instead of using CELL_SPACER for *all* cells that previously used
CELL_MULT_COL_SPACER, include the remaining number of spacers
following, and including, itself. This is encoded by adding to the
CELL_SPACER value.
So, a double width character will now store the character itself in
the first cell (just like before), and CELL_SPACER+1 in the second
cell.
A three-cell character would store the character itself, then
CELL_SPACER+2, and finally CELL_SPACER+1.
In other words, the last spacer is always CELL_SPACER+1.
CELL_SPACER+0 is used when padding at the right margin. I.e. when
writing e.g. a double width character in the last column, we insert a
CELL_SPACER+0 pad character, and then write the double width character
in the first column on the next row.
* Rename cursor.style value ‘bar’ to ‘beam’. ‘bar’ remains recognized,
but should eventually be deprecated and then removed.
* Add ‘cursor.beam-thickness’ option, a pt-or-px value specifying the
thickness of the beam cursor. Defaults to 1.5pt.
* Rename (and export) pt_or_px_as_pixels() to
term_pt_or_px_as_pixels()
* Change term_pt_or_px_as_pixels() to round point values instead of
truncating them.
This ensures different seat’s don’t step on each others IME pre-edit
state.
It also removes most dependencies on having a valid term pointer for
many IME operations.
We’re still not all the way, since we support disabling IME with a
private mode, which is per terminal, not seat.
Thus, we still require the seat to have keyboard focus on one of our
windows.
Closes#324. But note that *rendering* of multiple seat’s IME pre-edit
strings is still broken.
When the user has set a custom line-height, we now adjust it when
increasing/decreasing (“zooming”) the font size at run-time.
Previously, the line-height was fixed at the size specified in
foot.ini.
term_print() is called whenever the client application “prints”
something to the grid. It is called for both ASCII and UTF-8
characters, and needs to handle sixels, insert mode and ASCII
vs. graphical charsets.
Since it’s on the hot path, this becomes unnecessarily slow.
This patch adds a “fast” version of term_print(), tailored for the
common case: ASCII characters in non-insert mode, without any sixels
and non-graphical charsets.
A new function, term_update_ascii_printer(), has been added, and must
be called whenever:
* The currently selected charset *index* changes
* The currently selected charset changes (from ASCII to graphical, or
vice verse)
* Sixels are added to the grid
* Sixels are removed from the grid
* Insert mode is enabled/disabled
When P2=1, empty pixels are transparent.
This patch also changes the behavior of P2=0|2, from setting empty
pixels to the default background color, to instead use the *current*
background color.
To implement this, a couple of changes are needed:
* Sixel pixels always use alpha=1.0, except for *empty* cells when
P2=1 (i.e. transparent pixels).
* The renderer draws sixels with the OVER operator, instead of the SRC
operator.
* The renderer *must* now render the cells beneath the sixel. As an
optimization, this is only done for sixels where P2=1. I.e. for
fully opaque sixels, there’s no need to render the cells beneath.
The sixel renderer isn’t yet hooked into the multi-threaded
renderer. This means *rows* (not just the cells) beneath
maybe-transparent sixels are rendered single-threaded.
Closes#391.
All-empty pixels rows in the last sixel row should not be included in
the final sixel image.
This allows applications to emit sixels whose height is not a multiple
of 6, and is how XTerm works.
This is done by tracking the largest row number that contains
non-empty pixels.
In unhook, when emitting the image, the image height is adjusted based
on this value.
