iris-ai
53e61289f5
`lerp_inv` returns `Option`. Inverting a lerp over a range of zero length has no one answer, and `div_or`'s fallback picked one: the start of the range. Measured, that is not a wrong number so much as a plausible one -- taking a part out of a box fixed at the top of the window hands back exactly what went in, and out of a box fixed at the middle hands back the parent's own `rel` of 0.5 as if it were the child's fraction. Either way the caller cannot tell that nothing was recovered, which is the defect; the previous commit's claim that it "returns a rel of 0" is right only for the first case. `UiScalar::outside` and `UiSpan::outside` follow it to `Option`, and `Remap` is the answer at the region level: `new` says whether a drawing in one box can be put in another and `apply` then cannot fail, so `try_reuse` asks once for a whole subtree and `reusable` goes back to reporting only what the widget claims. That replaces the predicate the last commit put in `reusable`, which stated the same rule in a second place. `DivOr` existed only for the fallback and is gone, along with `UiRegion::outside` and `UiVec2::outside`, which had no callers once `Remap` owned the operation. `UiRegion::axis` took `&mut self` to return a shared reference; `Remap::new` needs it on a shared one. This does not redraw less. `Remap::new` refuses exactly what the predicate refused; what it buys is one statement of the rule and a remap that cannot half-apply. Counted on a resize, with the old wipe-everything for comparison: 20 padded rows, 101 widgets 101 draws -> 0 the `tabs` example 73 draws -> 0 the `text` example 49 draws -> 48 So the saving is whole where a resize does not change any widget's size, and nil in `text`, where both paragraphs rewrap to a different height and the relayout that forces reaches the root. The last commit's message oversold that case. Checked: fmt, clippy and 35 tests. `tabs` (with the image replay), `view` and `minimal` still byte-identical to `upstream/main`, `text` unchanged, and the live sway resize round trip still matches a cold start at each size.
28 lines
998 B
Rust
28 lines
998 B
Rust
//! What a drawing can be taken out of, and what it cannot.
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use iris::core::{Remap, UiRegion, UiScalar, UiSpan};
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/// A box `size` tall whose top is `rel` of the way down the window.
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fn fixed(rel: f32, size: f32) -> UiRegion {
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UiRegion::new(
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UiSpan::FULL,
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UiSpan::new(UiScalar { rel, abs: 0.0 }, UiScalar { rel, abs: size }),
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)
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}
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#[test]
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fn a_fixed_box_can_be_carried_but_not_stretched() {
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let from = fixed(0.0, 164.0);
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assert!(Remap::new(from, UiRegion::FULL).is_none());
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assert!(Remap::new(from, fixed(0.5, 164.0)).is_some());
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assert!(Remap::new(from, fixed(0.0, 98.0)).is_none());
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}
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#[test]
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fn a_relative_box_can_be_stretched_to_any_other() {
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let remap = Remap::new(UiRegion::FULL, fixed(0.0, 98.0)).expect("relative boxes remap");
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// A part that filled the window keeps filling what replaced it, which is
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// exactly what `outside` could not say for a box of a fixed length.
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assert_eq!(remap.apply(UiRegion::FULL), fixed(0.0, 98.0));
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}
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