This implements gamma-correct blending, which mainly affects font
rendering.
The implementation requires compile-time availability of the new
color-management protocol (available in wayland-protocols >= 1.41),
and run-time support for the same in the compositor (specifically, the
EXT_LINEAR TF function and sRGB primaries).
How it works: all colors are decoded from sRGB to linear (using a
lookup table, generated in the exact same way pixman generates it's
internal conversion tables) before being used by pixman. The resulting
image buffer is thus in decoded/linear format. We use the
color-management protocol to inform the compositor of this, by tagging
the wayland surfaces with the 'ext_linear' image attribute.
Sixes: all colors are sRGB internally, and decoded to linear before
being used in any sixels. Thus, the image buffers will contain linear
colors. This is important, since otherwise there would be a
decode/encode penalty every time a sixel is blended to the grid.
Emojis: we require fcft >= 3.2, which adds support for sRGB decoding
color glyphs. Meaning, the emoji pixman surfaces can be blended
directly to the grid, just like sixels.
Gamma-correct blending is enabled by default *when the compositor
supports it*. There's a new option to explicitly enable/disable it:
gamma-correct-blending=no|yes. If set to 'yes', and the compositor
does not implement the required color-management features, warning
logs are emitted.
There's a loss of precision when storing linear pixels in 8-bit
channels. For this reason, this patch also adds supports for 10-bit
surfaces. For now, this is disabled by default since such surfaces
only have 2 bits for alpha. It can be enabled with
tweak.surface-bit-depth=10-bit.
Perhaps, in the future, we can enable it by default if:
* gamma-correct blending is enabled
* the user has not enabled a transparent background
We've been trying to performance optimize reflow by "chunking" cells;
try to gather as many as possible, and memcpy a chunk at once.
The problem is that a) this quickly becomes very complex, and b) is
very hard to get right for multi-column characters, especially when we
need to truncate long ones due to the window being too small.
Refactor, and once again walk and copy all cells one by one. This is
slower, but at least it's correct.
This brings initial support for the new kitty text-sizing
protocol. Note hat only the width-parameter ('w') is supported. That
is, no font scaling, and no multi-line cells.
For now, only explicit widths are supported. That is, w=0 does not yet
work.
There are a couple of changes to the renderer, to handle e.g.
OSC 66 ; w=6 ; foobar ST
There are two ways this can get rendered, depending on whether
grapheme shaping has been enabled. We either shape it, and get an
array of glyphs back that we render. Or, we rasterize each codepoint
ourselves, and render each resulting glyph.
The two cases ends up in two different renderer loops, that worked
somewhat different. In particular, the first case has probably never
been tested/used at all...
With this patch, both are changed, and now uses some heuristic to
differentiate between multi-cell text strings (like in the example
above), or single-cell combining characters. The difference is mainly
in which offset to use for the secondary glyphs.
In a multi-cell string, each glyph is mapped to its own cell, while in
the combining case, we try to map all glyphs to the same cell.
The protocol states:
If the width or height arguments are zero, it means the client
should decide its own window dimension. This may happen when the
compositor needs to configure the state of the surface but doesn't
have any information about any previous or expected dimension.
The wording is a bit ambiguous; does it mean we should set *both*
width and height to values we choose, even if only one dimension is
zero in the configure event? Or does it mean that we should choose the
value for the dimension that is zero in the configure event?
Regardless, it's pretty clear that it does *not* mean we should *only*
choose width and height if *both* dimensions are zero in the configure
event. This is foot's behavior before this patch, meaning if only one
of them is zero, foot assumed the compositor wanted us to set the
width (or height) to zero...
Change this, so that we now choose value for the "missing" dimension,
but do use the compositor provided value for the other dimension.
Closes#1925
Relevant issues:
* https://gitlab.freedesktop.org/wayland/wayland-protocols/-/issues/155
* https://github.com/YaLTeR/niri/issues/1050
A compositor will not send a frame callback for our main window if it
is fully occluded (for example, by a fully opaque overlay...). This
causes the overlay to stuck.
For regular buffers, it _should_ be enough to *not* hint the
compositor it's opaque. But at least some compositor special cases
single-pixel buffers, and actually look at their pixel value.
Thus, we have two options: implement frame callback handling for the
overlay sub-surface, or ensure we don't use a fully opaque
surface. Since no overlays are fully opaque by default, and the flash
surface is the only one that can be configured to be
opaque (colors.flash-alpha), and since adding frame callback handling
adds a lot of boilerplate code... let's go with the simpler solution
of
This fixes flickering when foot is forced to double-buffer (e.g when
running under KDE, or smithay based compositors).
Since the damage region isn't updated, the sixel images aren't
included in the memcpy that is done to transfer the last frame's
updated regions to the next frame.
As a result, every other frame will have the sixels, while the others
don't.
Closes#1851
When scanning the grid for all-dirty rows (that we can remove from the
damage region we're about to memcpy from the old frame), check the
row->dirty bit, and skip scanning the cells of that row altogether.
We're only looking for rows where all cells are dirty - those rows can
be removed from the region we copy from the old frame, since the
entire row will be re-rendered anyway.
If a row is clean, it *must* be copied from the old frame.
When trying to set a custom cursor shape, we first validate it. This
is done by checking against known server-side names, and then trying
to load the cursor from the client side cursor theme.
But, if we're using server side names, there is no theme loaded, and
foot crashed.
Fix by checking if we have a theme loaded, and if not, fail the cursor
shape name validation.
* The toplevel icon is now set to the app-id, unless "overridden" by
OSC-1 or OSC-0.
* Implemented OSC-1
* OSC-0 extended to also set the icon
* Implemented CSI 20 t - report window icon
* Implemented CSI 21 t - report window title
* Implemented CSI 22 ; 1 t - push window icon
* Implemented CS 23 ; 1 t - pop window icon
* Extended CSI 22/23 ; 0 t to also push/pop the icon
* Verify app-id set by OSC-176 is valid UTF-8
* Verify icon set by OSC-0/1 is valid UTF-8
The config system allows setting the scrollback lines to
2**32-1.
However, the total number of grid lines is the scrollback lines plus
the window size, and then rounded *up* to the nearest power of two.
Furthermore, the number of rows is represented with a plain 'int'
throughout the code base.
The largest positive integer that fits in an int is 2**31-1. That
however, is not a power of two.
The largest positive integer, that also is a power of two, that fits
in an int is 2**30, or 1073741824.
Ideally, we'd just cast the line count to a 64-bit integer, and call
__builtin_clzl{,l}() on it, and then take the smallest value of that,
or 2**30. But, for some reason, __builtin_clzl(), and
__builtin_clzll() appears to ignore bits above 32, despite they being
typed to long and long long. Bug?
Instead, ensure we never call __builtin_clz() on anything larger than
2**30.
Closes#1828
* Render button as highlighted only when pointer is above them
* Releasing the mouse button while *not* on the button does *not*
activate the button
When pressing, and holding, a mouse button, the compositor keeps
sending motion events for the surface where the button was pressed,
even if the mouse has moved outside it.
We also don't get any surface leave/enter events.
This meant that the button was rendered as highlighted, and a click
registered, if the user pressed the mouse button while on the button,
and then moved the cursor away from the button before releasing the
button.
This patch fixes it, by checking if the current cursor coordinates
fall within the button surface.
This implements
https://gist.github.com/rockorager/e695fb2924d36b2bcf1fff4a3704bd83,
in-band window resize notifications.
When user enables private mode 2048 (in-band resize
notifications), *always* send current size, even if the mode is
already active.
This ensures applications can rely on getting a reply from the
terminal.
10/11/17/19 were already merged, so this patch just stops special
casing 12 (cursor color).
In preparation for XTPUSHCOLORS/XTPOPCOLORS, the cursor colors are
moved from their own struct, into the 'colors' struct.
Also fix a bug where OSC 17/19 queries returned OSC-11 data.
Reproducer:
CFLAGS='-Og -g' meson setup --buildtype=debug bld
ninja -C bld
Error message:
../render.c: In function ‘draw_styled_underline’:
../render.c:490:19: error: ‘y_ofs’ may be used uninitialized
[-Werror=maybe-uninitialized]
490 | const int top = y + y_ofs;
| ^~~
../render.c:405:9: note: ‘y_ofs’ was declared here
405 | int y_ofs;
| ^~~~~
Before this patch, we asserted both the cursor foreground, and
background colors had been set. This is true in most cases; the config
system enforces it.
It is however possible to set only the cursor background color, while
leaving the foreground (text) color unset:
* Use a foot config that does *not* configure the cursor colors. This
means foot will invert the default fg/bg colors when rendering the
cursor.
* Override the cursor color using an OSC-12 sequence. OSC-12 only sets
the background color of the cursor, and there is no other OSC sequence
to set the cursor's text color.
To handle this, remove the assertion, and simply split the logic for
the cursor backgound and foreground colors:
* Use the configured background color if set (either through config or
OSC-12), otherwise use the default foreground color.
* Use the configured foreground color if set (through config),
otherwise use the default background color.
Try to make the 'dotted' style appear more even, and less like each
cell is rendered separately (even though they are).
Algorithm:
Each dot is a square; it's sides are that of the font's line
thickness.
The spacing (gaps) between the dots is initially the same width as the
dots themselves.
This means the number of dots per cell is the cell width divided by
the dots' length/width, divided by two.
At this point, there may be "left-over" pixels.I.e. the widths of the
dots and the gaps between them may not add up to the width of the
cell.
These pixels are evenly (as possible) across the gaps.
There are still visual inaccuracies at small font sizes. This is
impossible to fix without changing the way underlines are rendered, to
render an entire line in one go. This is not something we want to do,
since it'll make styled underlines, for a specific cell/character,
look differently, depending on the surrounding context.
When doing an interactive resize, we create a small grid copy of the
current viewport, and then do a non-reflow resize.
When the interactive resize is done, we do a proper reflow. This is
for performance reasons.
When creating the viewport copy, we also need to copy the styled
underlines. Otherwise, styled underlines will be rendered as plain
underlines *while resizing*.
This was originally contributed by @kraftwerk28 in
https://codeberg.org/dnkl/foot/pulls/1099
Here, we re-use the rendering logic only, as attribute tracking has
been completely rewritten.
This is work in progress, and fairly untested.
This adds initial tracking of styled underlines. Setting attributes
seems to work (both color and underline style). Grid reflow has *not*
been tested.
When rendering, style is currently ignored (all styles are rendered as
a plain, legacy underline).
Color however, *is* applied.
Don't re-create the single-pixel buffer, unless necessary.
The buffer itself doesn't have a size. That means we can re-use the
buffer if the last frame's overlay style matches the current frame's
style.
What we *do not* know is whether the current frame's size is the same
as the last frame's.
This means we still have to set the viewport destination, and commit
the surface.
The unicode-mode, and flash overlays are single color buffers. This
means we can use the single-pixel buffer protocol.
It's undefined whether the compositor will release the buffer or not;
to make things easier, simply destroy the buffer as soon as we've
committed it.
Note that since compositors don't necessarily release single-pixel
buffers, we can't plug them into our own buffer interface. This means
we can't use buffer pointers to check if we can re-use the previous
buffer (i.e. we can skip comitting a new buffer), or if we have to
create a new one.
It's _almost_ enough to just check if the last overlay style is the
same as the current one. Except that that doesn't take window resizes
into account...
This fixes an issue where entering unicode-mode in one foot client,
also enabled unicode-mode on other foot clients. Both
visually (although glitchy), and in effect.
The reason the state was originally in the seat objects, was to fully
support multi-seat. That is, one seat/keyboard entering unicode-mode
should not affect other seats/keyboards.
The issue with this is that seat objects are Wayland global. Thus, in
server mode, all seat objects are shared between the foot clients.
There is a similarity with IME, which also keeps state in the
seat. There's one big difference, however, and that is IME has Wayland
native enter/leave events, that the compositor emits when windows are
focused/unfocused. These events allow us to reset IME state. For our
own Unicode mode, there is nothing similar.
This patch moves the Unicode state from seats, to the terminal
struct. This does mean that if one seat/keyboard enters Unicode mode,
then *all* seats/keyboards will affect the unicode state. This
potential downside is outweighed by the fact that different foot
clients no longer affect each other.
Closes#1717
This option controls how we render the cursor when the terminal window
is unfocused.
Possible values are:
* hollow: the default, and how we rendered the cursor before this
patch.
* unchanged: render the cursor exactly the same way as when the window
is focused.
* none: do not render any cursor at all
Closes#1582
Before this patch, we used legacy X11 xcursor names, and didn't really
have any fallback handling in place (we only tried to fallback to
"xterm", regardless of which cursor shape we were trying to load).
This patch changes two things:
1. Improved fallback support. cursor_shape_to_string() now returns a
list of strings. This allows us to have per-shape fallbacks, and any
number of fallbacks.
2. We prefer CSS xcursor names over legacy X11 names.
render_xcursor_update() is called when we've loaded a new xcursor
image, and needs to display it. The reason it's not pushed to the
compositor immediately is to ensure we don't flood the Wayland socket
with xcursor updates.
Normally, it's only called when we *succeed* to load a new xcursor
image. I.e. if we try to load a non-existing xcursor image, we never
schedule an update.
However, we _can_ still end up in render_xcursor_update() without a
valid xcursor image. For example, we have loaded a valid xcursor
image, and scheduled an update. But before the update runs, the user
moves the cursor, and we try to load a new xcursor image. If it fails,
we crash when the previously scheduled update finally runs.
Closes#1624
