irisandClaude Opus 5
144c402181
Iris, from her phone: "some stuttering when flinging in particular. Harder to notice with my finger directly moving the scroll." Her fling phase was 103fps on a 120Hz screen at p50 6.3ms. Two of the four things found are corrections to the instrument, not the renderer. The swapchain acquire -- `get_current_texture`, which *blocks* until the compositor frees an image -- was inside the span the report called iris's CPU work, so a fling comfortably ahead of the display read as milliseconds of being slow. A frame is now three measured parts (`FrameParts`: build, acquire, submit), per phase as well as per run. And nothing could say a frame was never *produced*: `late` counts frames that cost too much, which a reader does not see, while a frame that never happens leaves the last one up for two refreshes, which is the stutter. `PhaseStats::missed` counts vsyncs nothing was drawn for. It closes on the emulator: 1548 frames + 452 missed over 33.0s at 60Hz is 1980 vsyncs. The other two are the frame loop. `Choreographer.postFrameCallback` schedules for the next vsync after the call, and iris asked at the *end* of the callback -- so any frame whose work ran past the boundary registered too late and got the vsync after, one frame over budget silently costing a second. It is asked for immediately after `tick_animations` now, on both backends. And the fling was advanced on `Instant::now()` rather than the vsync `do_frame` carries: frames are presented on an even cadence whatever clock computes them, so sampling the spline at "whenever the callback ran" moves the content unevenly with no frame late enough to appear in any report -- and a drag never had it, which is the asymmetry Iris described. `PointerClock` is `DeviceClock` and the view keeps one, anchored by whichever of a touch or a frame comes first, so a fling is advanced on the clock its velocity was measured on. `opt-level` for the Android release build goes from "s" to 3. The table in RUST.md picked "s" on bytes alone; over the same warm fling eight times iris's own per-frame work is p90 0.15ms/p99 0.42ms at "s" against p90 0.09ms/p99 0.26ms at 3, for 1.8 MB of arm64 APK. `app-rust/tests/fling_profile.rs` is the rig that established what a fling frame actually costs and is kept for next time (Iris: "please keep the profiling rig around for future use"): only one frame in six lays anything out, and the multi-millisecond spikes are all first-pass. Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
iris
My experimental attempt at a rust ui library (also my first ui library).
It's currently designed around using retained data structures (widgets), rather than diffing generated trees from data like xilem or iced. This is an experiment and I'm not sure if it's a good idea or not.
Examples are in examples, eg. cargo run --example tabs.
Goals, in general order:
- does what I want it to (text, images, video, animations)
- very easy to use ignoring ergonomic ref counting
- reasonably fast / efficient (a lot faster than electron, save battery life, try to beat iced and xilem)
dev details
not targeting web rn cause wanna use actual nice gpu features & entire point of this is to make desktop apps / not need a web browser
general ideas trynna use rn / experiment with:
- retained mode
- specifically designed around wgpu so there's no translation
- postfix functions for most things to prevent unreadable indentation (going very well)
- events can be done directly where you draw the widgets
- almost no macros in user code & actual LSP typechecking (variadic generics if you can hear me please save us)
- relative anchor + absolute offset coord system (+ "rest" / leftover during widget layout)
- single threaded ui & pass context around to make non async usage straightforward (pretty unsure about this)
- widgets store outside of the actual rendering so they can be moved around and swapped easily (unsure about this but seems to work good for now)
under heavy initial development so not gonna try to explain status, maybe check TODO for that; sizable chance it gets a rewrite once I know everything I need and what seems to work best
it's called iris because it's the structure around what you actually want to display and colorful