previously drw_text would do the width calculations as if
invalid utf8 sequences were replaced with U+FFFD but would pass
the invalid utf8 sequence to xft to render where xft would just
cut it off at the first invalid byte.
this change makes invalid utf8 render as U+FFFD and avoids
sending invalid sequences to xft. the following can be used to
check the behavior before and after the patch:
$ printf "0\xef1234567\ntest" | dmenu
Ref: https://lists.suckless.org/dev/2407/35646.html
this changes the utf8decode function to:
* report when an error occurs
* report how many bytes to advance on error
these will be useful in the next commit to render invalid utf8
sequences.
the new implementation is also shorter and more direct.
1. use `unsigned int` to store the codepoints, this avoids waste on
common case where `long` is 64bits. and POSIX guarantees `int` to be
at least 32bits so there's no risk of truncation.
2. since switching to `unsigned int` cuts down the memory requirement by
half, double the cache size from 64 to 128.
3. instead of a linear search, use a simple hash-table for O(1) lookups.
this patch just rejects *any* 0 width draws, which is surely an error by
the caller.
this also guards against cases where the width is too small for the
ellipsis to fit, so ellipsis_w will remain 0.
reported by Bakkeby <bakkeby@gmail.com>
this was the last piece of the puzzle, the case where we can't find any
font to draw the codepoint.
in such cases, we use XftFontMatch() which is INSANELY slow. but that's
not the real problem. the real problem was we were continuously trying
to match the same thing over and over again.
this patch introduces a small cache, which keeps track a couple
codepoints for which we know we won't find any matches.
with this, i can dump lots of emojies into dmenu where some of them
don't have any matching font, and still not have dmenu lag insanely or
FREEZE completely when scrolling up and down.
this also improves startup time, which will of course depend on the
system and all installed fonts; but on my system and test case i see the
following startup time drop:
before -> after
60ms -> 34ms
getting the width of a string is an O(n) operation, and in many cases
users only care about getting the width upto a certain number.
instead of calling drw_fontset_getwidth() and *then* clamping the
result, this patch introduces drw_fontset_getwidth_clamp() function,
similar to strnlen(), which will stop once we reach n.
the `invert` parameter was overloaded internally to preserve the API,
however library users should be calling drw_fontset_getwidth_clamp() and
not depend upon internal behavior of drw_text().
this patch makes some non-trivial changes, which significantly improves
the performance of drawing large strings as well as fixes any issues
regarding the printing of the ellipsis when string gets truncated.
* performance:
before there were two O(n) loops, one which finds how long we can go
without changing font, and the second loop would (incorrectly) truncate
the string if it's too big.
this patch merges the overflow calculation into the first loop and exits
out when overflow is detected. when dumping lots of emojies into dmenu,
i see some noticeable startup time improvement:
before -> after
460ms -> 360ms
input latency when scrolling up/down is also noticeably better and can
be tested with the following:
for _ in $(seq 20); do
cat /dev/urandom | base64 | tr -d '\n' | head -c 1000000
echo
done | ./dmenu -l 10
* correctness:
the previous version would incorrectly assumed single byte chars and
would overwrite them with '.' , this caused a whole bunch of obvious
problems, including the ellipsis not getting rendered if then font
changed.
in addition to exiting out when we detect overflow, this patch also
keeps track of the last x-position where the ellipsis would fit. if we
detect overflow, we simply make a recursing call to drw_text() at the
ellipsis_x position and overwrite what was there.
so now the ellipsis will always be printed properly, regardless of
weather the font changes or if the string is single byte char or not.
the idea of rendering the ellipsis on top incase of overflow was
from Bakkeby <bakkeby@gmail.com>, thanks! however the original patch had
some issues incorrectly truncating the prompt (-p flag) and cutting off
emojies. those have been fixed in here.
This reverts commit c585e8e498.
It causes issues with truncation of characters when the text does not fit and
so on. The patch should be reworked and properly tested.
Calculates len & ew in drw_font_getexts loop by incrementing instead of
decrementing; as such avoids proportional increase in time spent in loop
based on provided strings size.
- extract drawitem function (code deduplication)
- fix bug where inputw was not correctly calculated from the widest item, but
just from the one with the longest strlen() which is not the same. It's better
now, but does not account for fallback fonts, since it would be too slow to
calculate all the correct item widths on startup.
- minor code style fixes (indentation, useless line breaks)
- libdraw, util: add drw.{c,h}, util.{c,h} and update code.
- libdraw: fix drw_rect(): use w and h parameter.
- libdraw: print errstr if last character in string was ":" (sbase).
- libdraw: drw_clr_free() allow valid free(NULL).
- config.def.h: set default font to monospace.
- cleanup() on exit.
- LICENSE: update license string for dmenu -v to 2015.
- LICENSE: add myself to LICENSE
