This was needed to fix various corner cases when doing blending of colors
in linear space. The new architecture has the same performance as the
old in the common case of opaque rendering with no UI layers or images.
In the case of only positive z-index images there is a performance
decrease as the OS Window is now rendered to a offscreen texture and
then blitted to screen. However, in the future when we move to Vulkan or
I can figure out how to get Wayland to accept buffers with colors in
linear space, this performance penalty can be removed. The performance
penalty was not significant on my system but this is highly GPU
dependent. Modern GPUs are supposedly optimised for rendering to
offscreen buffers, so we will see. The awrit project might be a good
test case.
Now either we have 1-shot rendering for the case of opaque with only ext
or all the various pieces are rendered in successive draw calls into an
offscreen buffer that is blitted to the output buffer after all drawing
is done.
Fixes#8869
monotonic() is extremely slow. This call was halving the CSI parsing
speed benchmark. Instead we use the time at which parsing of the current
input chunk was started. This should be within a few microseconds and
accurate enough for the cursor trail for which it is used.
Needed by the execrable ncurses. Adds an extra branch in the hot path,
sigh. Thanks to branch prediction it doesnt have any measurable impact
on the benchmark, thankfully.
While kitty is never going to underline detected URLs as the performance
of that is absurd, underlining hyperlinks specifically is acceptable,
since they dont require detection.
See #6766
Fix the problem caused by wrong cursor coordinates. No more messing with
the main cursor, instead the cursor is saved when receiving a pre-edit
text update and used for drawing later.
Update the overlay to the last visible cursor position before rendering
to ensure it always moves with the cursor. Finally, draw the overlay
after line rendering is complete, and restore the line buffer after
updating the rendered data to ensure that the line text being read is
correct at all times.
This also improves performance by only rendering once when changes are
made, eliminating the need to repeatedly disable and draw after various
commands and not even comprehensively.
