When trimming trailing empty rows from the final image, handle the RA
region correctly:
* If image is transparent, trim down to the last non-empty pixel row,
regardless of whether it is inside or outside the RA region.
* If image is opaque, trim down to either the last non-empty pixel
row, or the RA region, whatever is the largest height.
The raster attributes is, really, just a way to erase an area. And, if
the sixel is transparent, it's a nop.
The final text cursor position depends, not on our image size (which
is based on RA), but on the final graphical cursor position.
However, we do want to continue using it as a hint of the final image
size, to be able to pre-allocate the backing buffer.
So, here's what we do:
* When trimming trailing transparent rows, only trim the *image*, if
the graphical cursor is positioned on the last sixel row, *and* the
sixel is transparent.
* Opaque sixels aren't trimmed at all, since RA in this acts as an
erase that fills the RA region with the background color.
* The graphical cursor position is always adjusted (i.e. trimmed),
since it affects the text cursor position.
* The text cursor position is now calculated from the graphical cursor
position, instead of the image height.
After emitting a sixel, place the cursor on the character row touched
by the last sixel. The last sixel _may_ not be a multiple of 6
pixels, *if* the sixel had an explicit width/height set via raster
attributes.
This is an intended deviation from the DEC cursor placement algorithm,
where the cursor is placed on the character row touched by the last
sixel's *upper* pixel.
The adjusted algorithm implemented here makes it much easier for
applications to handle text-after-sixels, since they can now simply
assume a single text newline is required to move the cursor to a
character row not touched by the sixel.
Virtual machine monitor programs (e.g. QEMU, Cloud Hypervisor) expose
guest consoles as PTYs. With this patch, foot can access these guest
consoles.
Usually, the program used for accessing these PTYs is screen, but
screen is barely developed, doesn't support resizing, and has a bunch
of other unrelated stuff going on. It would be nice to have a
terminal emulator that properly supported opening an existing PTY.
The VMM controls the master end of the PTY, so to the other end (in
this case foot), it just behaves like any application running in a
directly-opened PTY, and all that's needed is to change foot's code to
support opening an existing PTY rather than creating one.
Co-authored-by: tanto <tanto@ccc.ac>
Before this patch, we reported scaled pixel values. This was rather
useless, since applications have no way of getting the scaling factor,
to "scale up" e.g. images.
Furthermore, the most common use of these queries are probably to
calculate the dimensions to use when emitting sixels.
Closes#1643
This functions reads the four top/left/bottom/right parameters,
validates them, and converts relative row numbers to absolute.
Returns true if the params are valid, otherwise false.
* DECCARA - change attributes in rectangular area
* DECRARA - reverse attributes in rectangular area
* DECCRA - copy rectangular area
* DECFRA - fill rectangular area
* DECERA - erase rectangular area
Not implemented:
* DECSERA - selective erase rectangular area
This function prints a single, non-double width, character to the
grid. It handles OSC-8 hyperlinks, but does not:
* update the cursor location
* erase sixels
* Store pointer to current pixel (i.e. pixel we're about to write to),
instead of a row-byte-offset. This way, we don't have to calculate the
offset into the backing image every time we emit a sixel band.
* Pass data pointer directly to sixel_add_*(), to avoid having to
calculate an offset into the backing image.
* Special case adding a single 1:1 sixel. This removes a for loop, and
simplifies state (position) updates. It is likely LTO does this for
us, but this way, we get it optimized in non-LTO builds as well.
In resize_vertically(), we assumed a sixel is 6 pixels tall. This is
mostly true, but not for non-1:1 sixels. Or, to be more precise, not
for sixels where 'pan' != 1.
This caused us to allocate too little backing memory, resulting in a
crash when we later tried to write to the image.
The kitty keyboard specification has been updated/clarified yet
again. Locked modifiers are to be ignored if the key event would
result in plain text without the locked modifier being enabled.
In short, locked modifiers are included in the set of modifiers
reported in a key event. But having a locked modifier enabled doesn't
turn all key events into CSIu sequences.
For example, with only the disambiguate mode enabled, pressing 'a', or
'shift+a' results in a/A regardless of the state of Caps- or NumLock.
But 'ctrl+a', which always results in a CSIu, will have a different
modifier list, depending on whether Caps- or NumLock are enabled.
This fixes an issue where some key combinations resulted in different
output (e.g. escape code vs. plain text) depending on the state of
e.g. the NumLock key. One such example is Shift+space. Another example
is Shift+BackSpace.
This patch also removes the hardcoded CapsLock filter, when
determining whether a key combo produces text or not, and instead uses
the locked modifiers as reported by XKB.
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
