feat(sweep): associative swept surfaces in the drawing's network

Swept surfaces made with SURFACEASSOCIATIVITY on keep their profile and
path and are written as a swept-surface action of the drawing's
associative network, reading the profile and path and their scale and
twist expressions. They follow edits of their sources.

Co-Authored-By: Claude Opus 5.5 <[email protected]>

src/app/command_driver/solid3d.rs

@@ -489,6 +489,8 @@ impl OpenCADStudio {
             .collect::<Vec<_>>();
         // Group 294: a base point the user picked.
         let picked_base = options.base_point.is_some();
+        let several = profiles.len() > 1;
+        let picked = options;
         let options = sweep_model::sweep_selection_options(&selection, options);
         let pending = if profiles.is_empty() {
             None
@@ -532,8 +534,10 @@ impl OpenCADStudio {
                     continue;
                 }
             };
+            // An associative surface keeps the profile and path it reads.
+            let associative = surface && sweep_model::surface_associativity();
             let deletes_path =
-                crate::app::delobj_deletes_auxiliary(delete_objects, surface);
+                !associative && crate::app::delobj_deletes_auxiliary(delete_objects, surface);
             if deletes_path && self.tabs[i].scene.is_layer_locked(path_handle) {
                 failed += 1;
                 continue;
@@ -546,6 +550,14 @@ impl OpenCADStudio {
                     created,
                     &expressions,
                 );
+                if associative {
+                    // A picked base point, or the one several profiles share.
+                    let linked = crate::command::SweepOptions {
+                        base_point: if picked_base || several { options.and_then(|o| o.base_point) } else { None },
+                        ..picked
+                    };
+                    sweep_model::link_sweep_sources(&mut self.tabs[i].scene.document, created, handle, path_handle, &linked);
+                }
                 created
             } else {
                 self.add_solid_model(
@@ -558,7 +570,7 @@ impl OpenCADStudio {
                 failed += 1;
             } else {
                 created_handles.push(created);
-                if delete_profiles {
+                if delete_profiles && !associative {
                     consumed.push(handle);
                 }
                 if deletes_path {

src/app/commands/mod.rs

@@ -697,6 +697,7 @@ inventory::submit!(crate::command::CommandRegistration {
         "PDFOSNAP",
         "UOSNAP",
         "FIELDDISPLAY",
+        "SURFACEASSOCIATIVITY",
         "FIELDEVAL",
         "PDFIMPORTMODE",
         "PDFIMPORTFILTER",

src/app/commands/styleprops.rs

@@ -1093,6 +1093,7 @@ impl OpenCADStudio {
                     | "DGNOSNAP"
                     | "UOSNAP"
                     | "FIELDDISPLAY"
+                    | "SURFACEASSOCIATIVITY"
                     | "PDFIMPORTMODE"
                     | "PDFIMPORTFILTER"
                     | "PDFIMPORTLAYERS"
@@ -1301,6 +1302,28 @@ impl OpenCADStudio {
                         }
                         return Some(self.finish_dispatch(cmd));
                     }
+                    if name == "SURFACEASSOCIATIVITY" {
+                        use crate::scene::model::sweep_model;
+                        let current = i16::from(sweep_model::surface_associativity());
+                        match value.as_deref().map(|v| v.trim().parse::<i16>().ok().filter(|v| (0..=1).contains(v))) {
+                            Some(Some(mode)) => {
+                                if current != mode {
+                                    sweep_model::set_surface_associativity(mode == 1);
+                                    self.save_config();
+                                }
+                            }
+                            Some(None) => {
+                                self.command_line.push_error(crate::t!("Requires 0 or 1 only.").as_ref());
+                                self.command_line.push_output(&format!("Enter new value for SURFACEASSOCIATIVITY <{current}>:"));
+                                self.pending_setvar = Some(name.clone());
+                            }
+                            None => {
+                                self.command_line.push_output(&format!("Enter new value for SURFACEASSOCIATIVITY <{current}>:"));
+                                self.pending_setvar = Some(name.clone());
+                            }
+                        }
+                        return Some(self.finish_dispatch(cmd));
+                    }
                     if name == "FIELDDISPLAY" {
                         let current = i16::from(crate::entities::field::display());
                         match value.as_deref().map(|v| v.trim().parse::<i16>().ok().filter(|v| (0..=1).contains(v))) {

src/app/settings.rs

@@ -412,6 +412,8 @@ pub struct UserSettings {
     pub attdef_on_screen: bool,
     /// FIELDDISPLAY: fields show on a gray background.
     pub field_display: bool,
+    /// SURFACEASSOCIATIVITY: new surfaces stay associative to their sources.
+    pub surface_associativity: bool,
     /// Nested-copy symbol handling: false inserts, true binds.
     pub ncopy_bind: bool,
     /// Last Options page; unknown saved names fall back without rejecting the config.
@@ -823,6 +825,7 @@ impl Default for UserSettings {
             image_frame: 1,
             attdef_on_screen: true,
             field_display: true,
+            surface_associativity: true,
             ncopy_bind: false,
             cursor_type: CursorType::Crosshair,
             crosshair_color: None,

src/app/update/file.rs

@@ -678,6 +678,7 @@ impl OpenCADStudio {
             image_frame: crate::scene::frame::profile_image_mode(),
             attdef_on_screen: crate::modules::draw::draw::attdef::session().on_screen,
             field_display: crate::entities::field::display(),
+            surface_associativity: crate::scene::model::sweep_model::surface_associativity(),
             ncopy_bind: self.ncopy_bind,
             cursor_type: self.cursor_type,
             crosshair_color: self.crosshair_color,
@@ -787,6 +788,7 @@ impl OpenCADStudio {
         crate::scene::frame::set_profile_image_mode(s.image_frame);
         crate::modules::draw::draw::attdef::session().on_screen = s.attdef_on_screen;
         crate::entities::field::set_display(s.field_display);
+        crate::scene::model::sweep_model::set_surface_associativity(s.surface_associativity);
         self.ncopy_bind = s.ncopy_bind;
         self.cursor_type = s.cursor_type;
         self.crosshair_color = s.crosshair_color;