Home and Fit frame what is shown now; middle double-click goes Home (#701)

Home, Fit, the orbit pivot and the scene's depth range counted sketches the view doesn't draw (ones used by an extrude or revolve, ones in hidden components), so after a body moved away from its sketch Home framed the empty spot it came from. They now use the world-space bounds of what is shown now (view::visible_bounds / view::sketch_drawn, viewport::view_bounds). The pick-box cache holds its world state instead of its address. A middle-button double-click goes Home in every preset (Preferences › Navigation: Home, Fit or Off).

Fixes #689

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

crates/engine/src/view.rs

@@ -39,20 +39,32 @@ pub mod colors {
     pub const SECTION_CAP: Rgb = solidcraft_render::SECTION_CAP;
 }
 
-/// Bounds of everything visible.
+/// Bounds of everything visible now, in world space: shown bodies where their occurrences,
+/// joints and moves place them, and the sketches the view draws (not ones used by a feature,
+/// hidden ones, or ones in hidden components). What Home, Fit and the orbit pivot frame.
 pub fn bounds(s: &Session) -> Aabb3 {
+    visible_bounds(s, true)
+}
+
+/// [`bounds`], with the browser's Sketches folder shown (`sketches`) or hidden.
+pub fn visible_bounds(s: &Session, sketches: bool) -> Aabb3 {
     let st = s.world_state();
     let mut b = Aabb3::EMPTY;
-    let v = &s.visibility;
     for body in st.bodies.iter().filter(|x| s.body_visible(&x.name)) {
         b = b.union(&body.mesh().bounds());
     }
-    for ss in st.sketches.iter().filter(|x| !v.hidden_sketches.contains(&x.feature)) {
+    for ss in st.sketches.iter().filter(|x| sketch_drawn(s, x.feature, sketches)) {
+        // All four corners: on a tilted plane two opposite ones don't span the rectangle.
         if let Some((lo, hi)) = ss.sketch.bounds() {
-            for p in [lo, hi] {
+            for p in [lo, hi, solidcraft_geom::Vec2::new(lo.x, hi.y), solidcraft_geom::Vec2::new(hi.x, lo.y)] {
                 b.add(ss.plane.to_world(p));
             }
         }
+        for w in ss.sketch.wires.iter().filter(|w| !w.fit.is_empty() || !ss.sketch.view.hide_projected) {
+            for p in &w.pts {
+                b.add(*p);
+            }
+        }
     }
     b
 }
@@ -284,8 +296,38 @@ pub fn section_segments(m: &solidcraft_geom::Mesh, o: Vec3, n: Vec3) -> Vec<(Vec
 /// Is a sketch drawn? The active one is; others unless hidden. Finished sketches are hidden
 /// once a feature uses them, like Fusion's default, unless shown one by one.
 pub fn sketch_shown(s: &Session, id: u64) -> bool {
+    sketch_drawn(s, id, true)
+}
+
+/// Is a sketch drawn, with the browser's Sketches folder shown (`folder`) or hidden? The sketch
+/// being edited always is; otherwise not when hidden, nor in a hidden component, and one used by
+/// a feature only when shown on its own.
+pub fn sketch_drawn(s: &Session, id: u64, folder: bool) -> bool {
     let v = &s.visibility;
-    s.active_sketch == Some(id) || (!v.hidden_sketches.contains(&id) && (v.shown_sketches.contains(&id) || !sketch_consumed(s, id)))
+    if s.active_sketch == Some(id) {
+        return true;
+    }
+    if v.hidden_sketches.contains(&id) || !sketch_component_visible(s, id) {
+        return false;
+    }
+    v.shown_sketches.contains(&id) || (folder && !sketch_consumed(s, id))
+}
+
+/// Is the placement a sketch is drawn at shown (the active one while its component is being
+/// edited, else the component's first)?
+fn sketch_component_visible(s: &Session, id: u64) -> bool {
+    if s.visibility.hidden_occurrences.is_empty() {
+        return true;
+    }
+    let component = s.doc.feature(id).map_or(0, |f| f.component);
+    if component == 0 {
+        return true;
+    }
+    let path = match &s.active_occurrence_path {
+        Some(p) if s.active_component == component => p.clone(),
+        _ => s.doc.first_path(component),
+    };
+    s.occurrence_visible(&path)
 }
 
 /// Is a sketch used by a later feature?