* #217 DECSDM, and commented pseudocode for improved handling of transparent image cells
* oops forgot cargo fmt --all
* #217 set initial palette colors to match VT340
* #217 cleanup color_map initialization, fix sixel scrolling
* #217 remove large comment - transparency discussion for another time
This change also allows removing the dep on the palette crate,
which I found to be difficult to use (API changed often, and relied
on a lot of `.into` that was hard to follow and reconcile across
upgrades). We already pulled in the csscolorparse crate as an indirect
dep of colorgrad, so we can replace the color conversion we need for
sixel with that crate while we're in here.
refs: #1615
Previously overlooked because we didn't render or otherwise
change behavior: after running vttest and running ls, some
lines still had double width/height set.
This ensures that we remove that attribute when clearing
the screen.
This is using the existing attributes on the lines and rendering
the lines with doubled dimensions.
Selection on double width lines is a bit wonky because we don't
know how to translate the column position correctly.
This was used by the mux client when the session is tardy.
I've heard feedback that the greying out is distracting and not
especially useful, so I don't think this is any great loss.
This commit allows the following configuration:
```
wezterm -n --config 'colors = { selection_fg = "clear", selection_bg = "rgba:50% 50% 50% 50%" }'
```
which sets the selection_bg to fully transparent, and selection_bg to
50% transparent gray.
When selection_fg is fully transparent we'll use the normal fg color.
When selection_bg is partially (or fully!) transparent, it will be
alpha blended over the current cell background color.
To support this, the config file will now accept rgba colors specified
as 4 whitespace delimited numeric values. If a value ends with `%` it
is interpreted as a number in the range 0-100. Otherwise, it is
interpreted as a number in the range 0-255. The 4 values are
red, green, blue, alpha.
At this time, only the selection_fg and selection_bg settings accept
alpha values.
refs: #1615
Resolves a little bit of the awkward duplication of color types
between some of the crates by factoring them a little bit better.
This is prep for allowing specifying alpha for some colors
in the config.
This puts to final rest #478, wherein ligatured glyphs that span
cells would render portions of the glyph with the wrong fg color,
where wrong was usually the bg color and cause the glyph to turn
invisible when cursoring through the ligature.
The approach used here is to divide the glyph into 7 discrete strips
where each strip either intersects with the cursor, the selection, or
neither. That allows us to render each strip with the appropriate
foreground color.
This change simplifies some of the logic and allows some other code
to be removed, so that feels good!
As is tradition with these renderer changes, there's a good chance that
I overlooked something in testing and that the metrics or alignment
might be slightly off for some font/text combo. Let's see how this
goes!
refs: #784
refs: #478
refs: #1617
For a sequence like `e U+20d7` the intent is to render the `e` with
a vector arrow over the top.
This is typically implemented by fonts as an `e` followed by the
vector glyph (or vice versa), where either one of those may have
a zero advance so that the two elements are combined.
There were two problems here:
* During shaping we'd see the zero advance and assume that the entry
was useless and skip it
* During rendering, if we didn't think it had any cell width, we'd
not render it
Cursoring through that particular sequence can hide the vector
mark if the cursor is set to the default block cursor due to annoyances
in how the block cursor is rendered (it changes the fg color to match
the bg, but for elements outside where we think the cursor is, this
makes those elements invisible).
refs: https://github.com/wez/wezterm/issues/1617
This is a more robust approach; we make a separate pass to figure
out information about the (harfbuzz) cluster for a sequence of glyphs,
and then map that sequence back to the original cell sequence, and
from there compute the total cell width for the run, then distribute
the glyphs across the run.
This should yield more sane results for bidi.
Fixup the x-position math; it was still wonky despite the
efforts in 5f2c905db8 and
af92265ffb
refs: #1570
refs: #1607
refs: #1563
This allows unicode_version to be respected again when rendering.
The updated emoji-presentation.sh script now highlights this slightly
better by putting `.` characters after the emoji; unicode version 14
emoji presentation will show the `.` in the 3rd column, while earlier
versions will show it in the 2nd column for glyphs that are sensitive
to the version.
refs: #1607
refs: #1563
