This fixes the issue where particularly tall characters will get clipped
at the row boundary. This happens because even though a font describes
the line height with font metrics, individual glyphs do not have to
respect them, and we can see with emoji rendering sometimes they can
poke upwards past the line height. Also, it's trivially easy to
construct composing characters that become really tall, e.g. "x゙̂⃗", or
Tibetan scripts like "ཧཱུྃ".
To fix this, we do the following:
1. Remove the explicit clipping call at rendering.
2. Fix partial redraw to not lead to clipping / corruption. This is
quite tricky, because let's say we have a character that is tall
enough to touch other lines, if those lines are redraw but not the
line with the tall char, the redraw will paint over the parts of the
glyphs poking through. Alternatively if we redraw the line with the
tall chars we also need to expand the redraw region to make sure
other lines get repainted as well. To fix this properly, we should do
a proper glyph calculation when we receive the draw command before we
issue before we call `setNeedsDisplayInRect`, but since right now we
only extract glyph info later (during drawRect call), it's too late.
We just do the hacky solution by storing a variable
`redrawExpandRows` that tracks how many lines to expand for all
lines. It's a little hacky since this will affect all lines
permanently regardless if they have tall characters or not. The
proper fix may come later as an optimization (or when we do hardware
rendering via Metal).
3. Re-order the rendering so we have a two pass system, where we first
draw the background fill color for all rows, then the text. This
helps prevent things like Vim's window split or cursorline from
obscuring the text.
4. Add a preference to turn on clipping (old behavior). This helps
prevent odd issues with really tall texts (e.g. Zalgo text) making it
hard to see what's going on. The preference `MMRendererClipToRow` is
not exposed in UI for now as it's a relatively niche. It will be
exposed later when we have a dedicated render tab in settings.
Note that a lot of these characters only show their full height by doing
`set maxcombine=8` because the default (2) is quite low.
Part of the fix for #995
Problem: :runtime completion can be further improved.
Solution: Also complete the {where} argument values and adjust the
completion for that. (closes#11874)
Problem: Code handling low level MS-Windows events cannot be tested.
Solution: Add test_mswin_event() and tests using it. (Christopher Plewright,
closes#11622)
Problem: The "kitty" terminfo entry is not widespread, resulting in the
kitty terminal not working properly.
Solution: Go back to using "xterm-kitty" and avoid the problems it causes in
another way.
Problem: Using "xterm-kitty" for 'term' causes problems.
Solution: Remove the "xterm-" part when 'term' is set from $TERM. Detect a
few kitty-specific properties based on the version response
instead of the terminal name.
Problem: There is no way to get a list of swap file names.
Solution: Add the swapfilelist() function. Use it in the test script to
clean up. Remove deleting individual swap files.
Problem: Classes are not documented or implemented yet.
Solution: Make the first steps at documenting Vim9 objects, classes and
interfaces. Make initial choices for the syntax. Add a skeleton
implementation. Add "public" and "this" in the command table.
Problem: The keyboard state response may end up in a shell command.
Solution: Only request the keyboard protocol state when the typeahead is
empty, no more commands are following and not exiting. Add the
t_RK termcap entry for this.
Problem: It is not easy to see what client-server commands are doing.
Solution: Add channel log messages if ch_log() is available. Move the
channel logging and make it available with the +eval feature.
Problem: Still using simplified mappings when using the kitty keyboard
protocol.
Solution: Use the kitty_protocol_state value to decide whether to use
simplified mappings. Improve how seenModifyOtherKeys is set and
reset.
Problem: Cannot debug the Kitty keyboard protocol with TermDebug.
Solution: Add Kitty keyboard protocol support to the libvterm fork.
Recognize the escape sequences that the protocol generates. Add
the 'keyprotocol' option to allow the user to specify for which
terminal what protocol is to be used, instead of hard-coding this.
Add recognizing the kitty keyboard protocol status.
Problem: Only a change in the current window triggers the WinScrolled
event.
Solution: Trigger WinScrolled if any window scrolled or changed size.
(issue #11576)
Problem: A silent mapping may cause dots on the command line.
Solution: Don't show dots for completion if they are not going to be removed
again. (closes#11501)
Problem: col() and charcol() only work for the current window.
Solution: Add an optional winid argument. (Yegappan Lakshmanan,
closes#11466, closes#11461)
Problem: Solution for "!!sort" in closed fold is not optimal.
Solution: Use a different range instead of the subtle difference in handling
a range with an offset. (issue #11487)
