diff --git a/crates/engine/src/canvas/tools/handles.rs b/crates/engine/src/canvas/tools/handles.rs index 75410ec75..ecd29e67a 100644 --- a/crates/engine/src/canvas/tools/handles.rs +++ b/crates/engine/src/canvas/tools/handles.rs @@ -132,9 +132,10 @@ pub fn selection_frame(doc: &Document, sel: &[NodeId]) -> Option<(Affine, f64, f Some((rot * Affine::translate((b.x0, b.y0)), b.width(), b.height())) } -/// The rotation the Design panel shows for `ids` (degrees, counter-clockwise positive) when they -/// all share one, else 0 (the handle box is page-aligned then). Axis-aligned layers give 0, which -/// is the same as 90, 180 and 270 for stepping in 15 degrees. +/// The rotation `ids` share on the page (degrees, counter-clockwise positive), else 0 (the handle +/// box is page-aligned then). Figma's rotation field shows this page rotation, also for a layer +/// inside a rotated frame or group, and Shift lands it on multiples of 15 degrees. Axis-aligned +/// layers give 0, which is the same as 90, 180 and 270 for stepping in 15 degrees. pub fn shared_rotation_degrees(doc: &Document, ids: &[NodeId]) -> f64 { shared_rotation(doc, ids).map_or(0.0, |a| -a.to_degrees()) } diff --git a/crates/engine/src/transform_behaviour_tests.rs b/crates/engine/src/transform_behaviour_tests.rs index 1ad84fff0..fe6709ee4 100644 --- a/crates/engine/src/transform_behaviour_tests.rs +++ b/crates/engine/src/transform_behaviour_tests.rs @@ -403,6 +403,39 @@ fn shift_rotating_lands_on_multiples_of_15_not_steps_from_the_start() { assert!(near(got, 0.0), "-2.27° rounds to 0°: {got}"); } +/// Rotates a 120 × 80 layer inside a frame turned `frame_rot`, the layer at `start` on the page, +/// by `turn` from its corner, and returns its rotation on the page. +fn rotate_drag_in_frame(frame_rot: f64, start: f64, turn: f64, m: Mods) -> f64 { + let mut s = session(); + let f = id(&ex(&mut s, "frame.create", json!({"x": 0, "y": 100, "width": 400, "height": 400}))); + set(&mut s, &[f], json!({"rotation": frame_rot})); + let r = rect(&mut s, 100.0, 100.0, 120.0, 80.0, Some(f)); + set(&mut s, &[r], json!({"rotation": start - frame_rot})); + let page = |s: &Session| rotation_degrees(s.doc().unwrap().world_transform(r)); + assert!(near(page(&s), start), "the layer starts at {start}° on the page: {}", page(&s)); + ex(&mut s, "select.set", json!({"ids": [r]})); + let world = s.doc().unwrap().world_transform(r); + let (c, corner) = (world * Point::new(60.0, 40.0), world * Point::ZERO); + let from = corner + (corner - c) * 0.15; + let a = (from - c).atan2() - turn.to_radians(); + let to = c + figcraft_geom::Vec2::from_angle(a) * 80.0; + drag(&mut s, from, to, m); + page(&s) +} + +#[test] +fn shift_rotating_inside_a_rotated_frame_lands_the_page_rotation_on_multiples_of_15() { + // Measured in Figma (2026-11-10): the rotation field of a layer inside a frame turned 10° shows + // its rotation on the page, and Shift lands that on multiples of 15°: from 7°, turns of 40°, + // 6° and -10° end at 45°, 15° and 0°; without Shift 6° ends at 13°. Groups behave the same. + for (turn, want) in [(40.0, 45.0), (6.0, 15.0), (-10.0, 0.0)] { + let got = rotate_drag_in_frame(10.0, 7.0, turn, SHIFT); + assert!(near(got, want), "7° on the page turned by {turn}° with Shift: {got}, want {want}"); + } + let got = rotate_drag_in_frame(10.0, 7.0, 6.0, NONE); + assert!(near(got, 13.0), "a free turn: {got}"); +} + #[test] fn groups_scale_children_keeping_their_rotation_and_flip() { let mut s = session();