Not sure where that idiom comes from or why strings work in some places
(auto-coercion?). I picked it up off some example apps. But
https://love2d.org/wiki/love.mouse.isDown says it should be an integer.
manifestation: clicking past end of a long, wrapping line containing
non-ASCII would cause the cursor to disappear rather than position past
end of screen line. Hitting enter would then throw an assertion with the
following stack trace:
Error: text.lua:381: bad argument #2 to 'sub' (number expected, got nil)
stack traceback:
[love "boot.lua"]:345: in function <[love "boot.lua"]:341>
[C]: in function 'sub'
text.lua:381: in function 'insert_return'
text.lua:179: in function 'keychord_pressed'
main.lua:495: in function 'keychord_pressed'
keychord.lua:10: in function <keychord.lua:5>
app.lua:34: in function <app.lua:25>
[C]: in function 'xpcall'
cause: the click caused a call to Text.to_pos_on_line whose result was
not on a UTF-8 character boundary.
fix: make to_pos_on_line utf8-aware.
We have a regression since we started reclaiming love Text fragments
more aggressively in commit 69c5d844cc. Pressing pageup no longer knows
about any line's screen lines. Not fixed yet.
All signs so far seem to be that CPU is cheap for this application, but
memory is expensive. It's easy to get sluggish if the GC comes on.
After some experiments using https://github.com/yaukeywang/LuaMemorySnapshotDump,
one source of memory leaks is rendered fragments (https://love2d.org/wiki/Text
objects). I need to render text in approximately word-sized fragments to
mostly break lines more intelligently at word boundaries.
I've attached the files I used for my experiments (suffixed with a '.')
There's definitely still a leak in fragments. The longer I edit, the
more memory goes to them.
I've tried to keep the time period of the blinking similar to my
terminal.
Honestly I'm no longer sure if any of my experiments are showing a
statistically significant result. Let's see how it feels over a period
of time.
I'm testing this by moving the cursor around with my eyes closed, then
starting a stopwatch as I open my eyes. This seems to help a bit. I'm
able to acquire the cursor in 2s. At least the 10s outliers I used to
have with the circle or thin line don't seem to be happening.
I'm being unprincipled at the moment between pos and x,y coordinates.
Whatever is more convenient. Perhaps a cleaner approach will come to me
over time.
I almost pushed this to production. That would have been catastrophic;
the very first keystroke anyone typed into the editor would have failed.
And in the process, this fixes the next bug on my TODO list! Paste on
first line wasn't working. Now it is.
When long wrapping lines go past the current page, I find myself
scrolling before I get to the bottom. So let's scroll less, usually from
the start of the bottom-most line, even if it wraps multiple screen
lines.
The challenge with this is to ensure that a long line that fills the
whole page by itself doesn't get you stuck. I take some care to make
sure <pagedown> always makes forward progress.
Mouse stuff is pretty strenuous. For the first time I have to be careful
not to recompute too often. And I ran into a race condition for the
first time where resetting line.y within App.draw meant mouse clicks
were extremely unlikely to see line.y set.
Incredibly inefficient, but I don't yet know how to efficiently encode
undo mutations that can span multiple lines.
There seems to be one bug related to creating new drawings; they're not
spawning events and undoing past drawing creation has some weird
artifacts. Redo seems to consistently work, though.