refactor(display): trim isolines follow-up comments

src/app/commands/display.rs

@@ -502,23 +502,8 @@ impl OpenCADStudio {
                 self.command_line.push_output(crate::t!("REDRAWALL: viewports refreshed.").as_ref());
                 return Some(Task::none());
             }
-            // REGEN — full model regeneration (bump_geometry: geometry_epoch AND
-            // block_epoch; C4). No undo, no DB mutation, so do NOT touch
-            // self.tabs[i].dirty — a newly opened drawing must not become
-            // "modified" merely because tessellation caches were invalidated (C7).
-            // REGENALL is functionally identical (C5).
+            // Rebuild tessellation caches without modifying the document.
             "REGEN" | "REGENALL" => {
-                // Solid meshes carry the isoline count they were tessellated
-                // with: `add_entity_internal` and `update_entity` pass
-                // `header.isolines` into `tessellate_volume` and store the
-                // result. Bumping the geometry epoch clears the wire memo but
-                // never re-runs that, so changing ISOLINES left every existing
-                // solid showing the density it was born with, and REGEN — the
-                // command whose whole job is this — did not help.
-                //
-                // `populate_meshes_from_document` re-tessellates from the
-                // document and bumps the epoch itself, so it replaces the bump
-                // rather than adding to it.
                 self.tabs[i].scene.populate_meshes_from_document();
                 self.command_line.push_output(crate::t!("REGEN: regenerated model.").as_ref());
                 return Some(Task::none());
@@ -1903,32 +1888,13 @@ mod tests {
         let _ = app.run_command_line("REGENALL");
         assert!(!app.tabs[i].dirty, "REGENALL must not dirty the document either");
     }
-}
 
-#[cfg(test)]
-mod regen_tests {
-    use crate::app::OpenCADStudio;
-
-    /// A solid's mesh carries the isoline count it was tessellated with:
-    /// `add_entity_internal` and `update_entity` pass `header.isolines` into
-    /// `tessellate_volume` and store the result. REGEN used to bump the
-    /// geometry epoch and stop, which clears the wire memo but leaves
-    /// `scene.meshes` exactly as it was — reported on #1123 as "REGEN should
-    /// fix this, but the isolines keep visible".
-    ///
-    /// Building ACIS geometry here would be out of proportion, so the mesh map
-    /// is seeded with a stale entry instead: REGEN must rebuild the map from
-    /// the document, and an entry belonging to no entity cannot survive that.
-    /// Bumping alone would leave it in place.
     #[test]
     fn regen_rebuilds_the_mesh_map_rather_than_only_bumping_the_epoch() {
         let mut app = OpenCADStudio::new_for_test();
         app.automation_op(r#"{"op":"new"}"#);
         let i = app.active_tab;
 
-        // An entry belonging to no entity. Rebuilding the map from the document
-        // drops it; bumping the geometry epoch leaves it exactly where it is,
-        // which is the whole difference this fix turns on.
         let stale = acadrust::Handle::new(0xDEAD);
         app.tabs[i].scene.meshes.insert(stale, stale_mesh());
         let epoch_before = app.tabs[i].scene.geometry_epoch;
@@ -1937,17 +1903,14 @@ mod regen_tests {
 
         assert!(
             !app.tabs[i].scene.meshes.contains_key(&stale),
-            "REGEN must rebuild the mesh map, not leave what was there",
+            "REGEN left a stale mesh",
         );
         assert_ne!(
             app.tabs[i].scene.geometry_epoch, epoch_before,
-            "and it still has to bump the geometry epoch",
+            "REGEN did not bump the geometry epoch",
         );
     }
 
-    /// Dragging the isolines slider must not rebuild every solid's mesh on the
-    /// way — a drag emits a message per pixel, and the rebuild is the same work
-    /// REGEN does. It waits for the release, and only runs if the value moved.
     #[test]
     fn the_isolines_slider_rebuilds_once_on_release_and_not_while_dragging() {
         use crate::app::Message;
@@ -1978,8 +1941,6 @@ mod regen_tests {
             "releasing after a change rebuilds them",
         );
 
-        // A release with nothing changed since the last one is a click that
-        // moved nothing, and must not pay for a rebuild.
         let stale = seed(&mut app, i);
         let _ = app.update(Message::IsolinesChanged(0));
         let _ = app.update(Message::IsolinesReleased);
@@ -2010,4 +1971,3 @@ mod regen_tests {
         }
     }
 }
-