fix: a dimension from linked geometry keeps its side when the source moves past it (#614)

A point dimensioned from linked geometry (projected, included or intersected) keeps its side when a parameter moves the link's source past it: the solve reads sides and turns from the stored state instead of from beside the moved line, both on recompute and when editing the sketch.

Co-authored-by: NOWN-DEV <257771410+NOWN-DEV@users.noreply.github.com>

crates/engine/src/cmd/sketch_project_side_tests.rs

@@ -0,0 +1,180 @@
+//! A dimension from linked geometry keeps its side when the link's source moves: a point held
+//! 5 from a projected line stays on the side it was drawn on wherever a parameter takes the
+//! line, also past the place the point is stored at.
+
+use serde_json::{Value, json};
+use solidcraft_geom::Vec2;
+
+use crate::Session;
+
+fn run(s: &mut Session, id: &str, p: Value) -> Value {
+    match s.execute(id, &p) {
+        Ok(v) => v,
+        Err(e) => panic!("{id} {p}: {e}"),
+    }
+}
+
+/// Sketch `A`: the horizontal line `rail`, 100 long, at the height the parameter `height`
+/// (50) gives it.
+fn rail_sketch(s: &mut Session) {
+    run(s, "parameters.add", json!({"name": "height", "expression": "50 mm"}));
+    run(s, "sketch.create", json!({"plane": "XY", "name": "A"}));
+    run(s, "sketch.line", json!({"points": [[0, 50], [100, 50]], "ids": ["rail"]}));
+    run(s, "sketch.constraint.horizontal_vertical", json!({"line": "rail", "mode": "horizontal"}));
+    run(s, "sketch.constraint.horizontal_vertical", json!({"points": ["origin", "rail.start"], "mode": "vertical"}));
+    run(s, "sketch.dimension", json!({"entities": ["origin", "rail.start"], "value": "height"}));
+    run(s, "sketch.dimension", json!({"entities": ["rail"], "value": "100 mm"}));
+    run(s, "sketch.finish", json!({}));
+}
+
+/// Sketch `S` (left open): `rail` brought in by `command`, and the point `p` at (50, `y`),
+/// 50 from the origin horizontally. Returns the linked line.
+fn point_by_the_rail(s: &mut Session, command: &str, y: f64) -> String {
+    rail_sketch(s);
+    run(s, "sketch.create", json!({"plane": "XY", "name": "S"}));
+    let r = run(s, command, json!({"refs": [{"sketch": "A", "curve": "rail"}]}));
+    let rail = r["links"][0]["curves"][0].as_str().unwrap().to_string();
+    run(s, "sketch.point", json!({"point": [50, y], "id": "p"}));
+    run(s, "sketch.dimension", json!({"entities": ["origin", "p"], "type": "horizontal", "value": "50 mm"}));
+    rail
+}
+
+/// `p` held 5 from `line`: the dimension's parameter.
+fn five_from(s: &mut Session, line: &str) -> String {
+    let r = run(s, "sketch.dimension", json!({"entities": ["p", line], "type": "distance", "value": "5 mm"}));
+    r["param"].as_str().unwrap().to_string()
+}
+
+fn set_height(s: &mut Session, height: f64) {
+    run(s, "parameters.change", json!({"name": "height", "expression": format!("{height} mm")}));
+}
+
+/// Where the model has `p` of sketch `S`.
+fn p(s: &Session) -> Vec2 {
+    let st = s.model.state();
+    let sk = &st.sketch(s.doc.find_feature("S").unwrap().id).unwrap().sketch;
+    sk.point(sk.resolve_point("p").unwrap()).unwrap()
+}
+
+/// `p` is at (50, `y`), and the sketch has nothing to report.
+#[track_caller]
+fn assert_p(s: &Session, y: f64, when: &str) {
+    assert!(p(s).dist(Vec2::new(50.0, y)) < 1e-9, "{when}: {:?}", p(s));
+    let feature = s.model.result(s.doc.find_feature("S").unwrap().id).unwrap();
+    assert_eq!((&feature.error, &feature.warning), (&None, &None), "{when}");
+}
+
+/// A line of sketch `A` whose height a parameter drives, projected into sketch `S`, whose point
+/// is dimensioned 5 from the projection.
+#[test]
+fn a_distance_from_a_projected_line_keeps_its_side_when_the_source_moves_past() {
+    let mut s = Session::default();
+    let rail = point_by_the_rail(&mut s, "sketch.project", 45.0);
+    five_from(&mut s, &rail);
+    run(&mut s, "sketch.finish", json!({}));
+    assert_p(&s, 45.0, "drawn");
+    // The source drops below the point's stored place: the point stays below the projection.
+    for height in [20.0, 50.0, 6.0, 400.0] {
+        set_height(&mut s, height);
+        assert_p(&s, height - 5.0, &format!("height {height}"));
+    }
+    // Editing the sketch afterwards refreshes the projection first; the side is the one from before.
+    set_height(&mut s, 20.0);
+    run(&mut s, "sketch.edit", json!({"sketch": "S"}));
+    run(&mut s, "sketch.point", json!({"point": [80, 80]}));
+    run(&mut s, "sketch.finish", json!({}));
+    assert_p(&s, 15.0, "after an edit");
+}
+
+/// The same from the other side: the point above the line, the source rising past it and
+/// coming back; and with the line brought in by Include 3D Geometry.
+#[test]
+fn a_point_above_the_line_stays_above_when_the_source_rises_past_and_returns() {
+    for command in ["sketch.project", "sketch.include_3d"] {
+        let mut s = Session::default();
+        let rail = point_by_the_rail(&mut s, command, 55.0);
+        five_from(&mut s, &rail);
+        run(&mut s, "sketch.finish", json!({}));
+        for height in [80.0, 400.0, 50.0, 6.0, 50.0] {
+            set_height(&mut s, height);
+            assert_p(&s, height + 5.0, &format!("{command}, height {height}"));
+        }
+    }
+}
+
+/// Model geometry in a sketch on XZ (whose y runs down the model's Z): the top of a box whose
+/// height a parameter drives, as a projected edge, as an edge of a projected face and as a
+/// section of the body. The point is 5 below the top, inside the box.
+#[test]
+fn a_distance_from_model_geometry_keeps_its_side_when_the_model_moves_past() {
+    // A projected edge is found again by the point picked on it, so it follows small steps
+    // only; a face (by its name) and a body follow any.
+    let small: &[f64] = &[42.0, 50.0, 58.0, 50.0, 44.0];
+    let large: &[f64] = &[20.0, 50.0, 6.0, 400.0];
+    let cases = [
+        ("sketch.project", json!({"edge": [50, 0, 50]}), 0.0, small),
+        ("sketch.project", json!({"face": [50, 0, 25]}), 0.0, large),
+        ("sketch.intersect", json!({"body": "Body1"}), -20.0, large),
+    ];
+    for (command, link, front, heights) in cases {
+        let mut s = Session::default();
+        run(&mut s, "parameters.add", json!({"name": "height", "expression": "50 mm"}));
+        run(&mut s, "solid.box", json!({"corner": [0, front, 0], "length": 100, "width": 40, "height": "height"}));
+        run(&mut s, "sketch.create", json!({"plane": "XZ", "name": "S"}));
+        run(&mut s, command, json!({"refs": [link]}));
+        let curves = run(&mut s, "sketch.inspect", json!({}))["curves"].clone();
+        let high = |c: &Value, end: &str| (c[end][1].as_f64().unwrap() + 50.0).abs() < 1e-6;
+        let top = curves.as_array().unwrap().iter().find(|c| high(c, "start_at") && high(c, "end_at")).unwrap()["id"].as_str().unwrap().to_string();
+        run(&mut s, "sketch.point", json!({"point": [50, -45], "id": "p"}));
+        run(&mut s, "sketch.dimension", json!({"entities": ["origin", "p"], "type": "horizontal", "value": "50 mm"}));
+        five_from(&mut s, &top);
+        run(&mut s, "sketch.finish", json!({}));
+        // (An edge found again by its picked point says so in a warning.)
+        for height in heights {
+            set_height(&mut s, *height);
+            assert!(p(&s).dist(Vec2::new(50.0, 5.0 - height)) < 1e-9, "{command} {link}, height {height}: {:?}", p(&s));
+        }
+    }
+}
+
+/// Another projection added after the source moved stores the sketch without solving it: the
+/// sketch it stores is the one the model shows.
+#[test]
+fn a_projection_added_after_the_source_moved_leaves_the_side() {
+    let mut s = Session::default();
+    let rail = point_by_the_rail(&mut s, "sketch.project", 45.0);
+    five_from(&mut s, &rail);
+    run(&mut s, "sketch.finish", json!({}));
+    set_height(&mut s, 20.0);
+    run(&mut s, "sketch.edit", json!({"sketch": "S"}));
+    run(&mut s, "sketch.project", json!({"refs": ["origin"]}));
+    run(&mut s, "sketch.finish", json!({}));
+    assert_p(&s, 15.0, "after the projection");
+    set_height(&mut s, 50.0);
+    assert_p(&s, 45.0, "back at 50");
+}
+
+/// The side is still the user's to choose, by where the point is when the dimension is added:
+/// also when the source has moved past the point since it was drawn. That side is kept from
+/// then on, and through an edit of the dimension's value.
+#[test]
+fn a_dimension_added_after_the_source_moved_takes_the_side_its_point_is_on() {
+    let mut s = Session::default();
+    let rail = point_by_the_rail(&mut s, "sketch.project", 45.0);
+    run(&mut s, "sketch.finish", json!({}));
+    // Drawn below the line; the line drops below it.
+    set_height(&mut s, 20.0);
+    assert_p(&s, 45.0, "no distance yet");
+    run(&mut s, "sketch.edit", json!({"sketch": "S"}));
+    let distance = five_from(&mut s, &rail);
+    run(&mut s, "sketch.finish", json!({}));
+    assert_p(&s, 25.0, "dimensioned above the line");
+    for height in [50.0, 6.0, 400.0, 20.0] {
+        set_height(&mut s, height);
+        assert_p(&s, height + 5.0, &format!("height {height}"));
+    }
+    run(&mut s, "parameters.change", json!({"name": distance, "expression": "8 mm"}));
+    assert_p(&s, 28.0, "8 from the line");
+    set_height(&mut s, 6.0);
+    assert_p(&s, 14.0, "8 from the line, height 6");
+}