Merge pull request #7114 from dotCooCoo/feat/group-effect-after-members

Effects: a group's geometry effects reshape what its members draw

crates/engine/src/tests/expand.rs

@@ -535,9 +535,9 @@ fn expanded_art_keeps_the_random_transforms_the_canvas_drew() {
 }
 
 /// The reply lists each object whose appearance expanded once, by the id it has in the document,
-/// starting with the selected object. In "group copies" the two copies of the square share an id
-/// until Expand Appearance gives them ids of their own, and the reply names the group, then each
-/// copy by its new id.
+/// starting with the selected object. In "group copies" the group's art holds the square with its
+/// stroke's effect applied, so the reply names the group alone; the two copies of the square share
+/// ids until Expand Appearance gives every object in them an id of its own.
 #[test]
 fn the_reply_names_each_expanded_copy_by_its_own_id() {
     for case in RANDOM_CASES {
@@ -551,8 +551,17 @@ fn the_reply_names_each_expanded_copy_by_its_own_id() {
         assert!(ids.iter().all(|&i| s.doc().unwrap().doc.node(NodeId(i)).is_some()), "{case}: {ids:?}");
         if case == "group copies" {
             let art = node(&s, id);
-            let copies: Vec<u64> = art.children().unwrap()[0].children().unwrap().iter().map(|c| c.id.0).collect();
-            assert_eq!(ids, [vec![id.0], copies].concat(), "{case}");
+            assert_eq!(ids, [id.0], "{case}");
+            let copies = art.children().unwrap();
+            assert_eq!(copies.len(), 2, "{case}");
+            let mut seen = std::collections::HashSet::new();
+            let mut repeated = vec![];
+            art.walk(&mut |n| {
+                if !seen.insert(n.id) {
+                    repeated.push(n.id);
+                }
+            });
+            assert!(repeated.is_empty(), "{case}: {repeated:?}");
         }
     }
 }

crates/engine/src/tests/objexpand.rs

@@ -257,6 +257,25 @@ fn shadows_under_a_groups_or_an_objects_transform_expand_appearance_as_the_canva
     }
 }
 
+/// A group's Transform effect runs after its member's own Offset Path in Expand Appearance as on
+/// the canvas: the 100 pt square offset to 120 pt and scaled by half expands 60 pt wide.
+#[test]
+fn a_groups_effects_after_its_members_own_expand_as_the_canvas_draws_them() {
+    let mut s = session();
+    run(&mut s, "shape.rectangle", json!({"x": 50, "y": 50, "width": 100, "height": 100}));
+    run(&mut s, "effect.apply", json!({"effect": "path.offsetPath", "params": {"offset": 10}}));
+    run(&mut s, "object.group", json!({}));
+    run(&mut s, "effect.apply", json!({"effect": "distort.transform", "params": {"scaleH": 50, "scaleV": 50}}));
+    let before = render(&s);
+    run(&mut s, "effect.expandAppearance", json!({}));
+    let after = render(&s);
+    let diff = differing(&before, &after, 64);
+    assert_eq!(diff, 0, "{diff} pixels differ");
+    let doc = &s.doc().unwrap().doc;
+    let w = doc.node(doc.layers[0].id).and_then(|l| l.geometric_bounds()).unwrap().width();
+    assert!((w - 60.0).abs() < 1e-6, "{w}");
+}
+
 #[test]
 fn a_placed_gradient_moved_by_a_warp_expands_as_the_canvas_draws_it() {
     // The object's own effect, and the fill's (the first appearance item).