iris-aiandClaude Opus 5
d98969158f
A widget's region is now held in the coordinates of the slot it draws in rather than the window's, and `Painter::place` is how a container asks for a slot: it draws a child it decides the box of and may decide again. Everything under that slot is a fraction of its box, so placing the child a second time is one entry to write whether it moved or changed length. A child drawn any other way has no slot and shares its nearest ancestor's. That is what keeps the chain short. `chain_cost` measured depth as the cost -- free to 8, +42.6% at 16 -- and a slot per widget put a transcript's glyphs past that for nothing, since almost every slot was zero. `Span`, `Aligned` and `Scroll` are the containers that re-place a child after drawing it, and `tests/layout.rs` pins that four widgets between a span and a leaf leave the leaf's chain one deep. `UiRegion::stretch`, `UiRegion::stretchable` and `UiScalar::stretch` are gone. Nothing is inverted any more: a box that changed length is written to its slot, and the descendants recompose against it in the shader. That also retires the case the guard existed for, where a fixed length has no fraction to recover -- `tests/layout.rs` now stretches a 40-tall row on its other axis, which `stretchable` refused outright. What still walks the CPU is deciding who must draw again, which no chain can answer: `mark_resized` descends from the widget whose box changed and marks anything whose own box changed length and whose drawing reads it. A part of a box with no relative extent on an axis is a fixed length, and composing into it leaves none either, so the walk stops where a length did not change -- an 80-wide child in a widened row is not redrawn though it says `Redraw`. `Span`, `Pad`, `Stack`, `Offset`, `Aligned`, `SetSize` and `LayerOffset` say `Scale`: each places in fractions and offsets of its own box and none reads the box's pixel length. `Scroll` and `MaxSize` do read pixels and stay `Redraw`. 45 tests pass, five of them new. Render verification comes after the CPU side, per the owner. 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