Fixes#2190
The `q` value with chunk transmissions is a bit complicated. The initial
transmission ("start" command) `q` value is used for all subsequent
chunks UNLESS a subsequent chunk specifies a `q >= 1`. If a chunk
specifies `q >= 1`, then that `q` value is subsequently used for all
future chunks unless another chunk specifies `q >= 1`. And so on.
This commit importantly also introduces the ability to test a full Kitty
command from string request to structured response. This will let us
prevent regressions in the future and ensure that we are correctly
handling the complex underspecified behavior of Kitty Graphics.
- move wuffs code from src/ to pkg/
- eliminate stray debug logs
- make logs a warning instead of an error
- remove initialization of some structs to zero
Improve the performance of Kitty graphics by switching to the WUFFS
library for decoding PNG images and for "swizzling" G, GA, and RGB data
to RGBA formats needed by the renderers.
WUFFS claims 2-3x performance benefits over other implementations, as
well as memory-safe operations.
Although not thorougly benchmarked, performance is on par with Kitty's
graphics decoding.
https://github.com/google/wuffs
If the transmission medium is a local-only medium, ignore the "m"
key. The Kitty graphics protocol specification does not explicitly
call out this behavior (although the "m" key is only mentioned in
connection with remote clients) but that's how it's implemented in
Kitty and at least one client (mpv) relies on this behavior when
using the shared memory transmission medium.
https://sw.kovidgoyal.net/kitty/graphics-protocol/#the-transmission-mediumccc3bee9af/kitty/graphics.c (L547-L592)
It's possible for `self.grow` to be called within the body of the
function, and `self.grow` uses `self.cols` to create a new page if
there's no more room in the current one.
Adds a comptime function to enable conditional compilation against
different GTK versions that have added new API calls in newer versions
of GTK.
Use this function to get fractional scaling information for GTK
surfaces, which is only available with GTK 4.12+.
Handle `clonePartialRowFrom` errors in `insertLines` and `deleteLines`
by adjusting page capacity. To do this, I've rewritten both functions
with a new way of iterating rows by moving a tracked pin up/down.
Benchmarks seem to indicate that this has no effect on performance.
