feat: annotation scale system (CANNOSCALE, PSLTSCALE, MultiLeader, Leader)

- Scale popup dropdown replaces cycle behavior; paper-space viewport scale
  editable when a viewport is active/selected
- CANNOSCALE persisted via DXF $USERR1 (read on open, write on save)
- PSLTSCALE: linetype dash lengths scaled by viewport anno_scale so dashes
  appear uniform physical size in paper space
- MultiLeader: arrow size, dogleg length, and text height scale with
  anno_scale; leader line paths (world coords) stay fixed
- Leader: arrow size and hookline length scale with anno_scale; also
  corrects world_offset subtraction that was previously deferred to the
  TruckObject::Lines path

Co-Authored-By: Claude Sonnet 4.6 <[email protected]>

src/app/mod.rs

@@ -39,6 +39,7 @@ pub(super) struct H7CAD {
     vp_size: (f32, f32),
     snapper: Snapper,
     snap_popup_open: bool,
+    scale_popup_open: bool,
     /// Whether Tangent snap was enabled before a tangent-pick command started.
     pre_cmd_tangent: Option<bool>,
     /// Orthogonal drawing constraint (F8): constrains picks to 0°/90°/180°/270°.
@@ -322,6 +323,14 @@ pub enum Message {
     TogglePolar,
     /// Set polar tracking angle increment (right-click POLAR button).
     SetPolarAngle(f32),
+    /// Set the model-space annotation scale (CANNOSCALE equivalent).
+    SetAnnotationScale(f32),
+    /// Set the active viewport's custom_scale (paper space).
+    SetViewportScale(f64),
+    /// Toggle the scale picker popup open/closed.
+    ToggleScalePopup,
+    /// Close the scale picker popup.
+    CloseScalePopup,
     /// Toggle dynamic input overlay (F12).
     ToggleDynInput,
     /// Toggle object snap tracking (F11).
@@ -606,6 +615,7 @@ impl H7CAD {
             vp_size: (1280.0, 720.0),
             snapper: Snapper::default(),
             snap_popup_open: false,
+            scale_popup_open: false,
             pre_cmd_tangent: None,
             ortho_mode: false,
             polar_mode: false,

src/app/update.rs

@@ -60,6 +60,8 @@ impl H7CAD {
 
                 self.tabs[i].current_path = Some(path.clone());
                 self.tabs[i].scene.document = doc;
+                let stored = self.tabs[i].scene.document.header.user_real1;
+                self.tabs[i].scene.annotation_scale = if stored > 1e-9 { stored as f32 } else { 1.0 };
 
                 // Auto-resolve XREFs relative to the opened file's directory.
                 if let Some(base_dir) = path.parent() {
@@ -407,6 +409,7 @@ impl H7CAD {
                 let i = self.active_tab;
                 if let Some(path) = &self.tabs[i].current_path {
                     let path = path.clone();
+                    self.tabs[i].scene.document.header.user_real1 = self.tabs[i].scene.annotation_scale as f64;
                     match crate::io::save(&self.tabs[i].scene.document, &path) {
                         Ok(()) => {
                             self.command_line
@@ -468,6 +471,7 @@ impl H7CAD {
                 let (_, version) = crate::io::parse_save_format(&self.save_dialog_format);
                 let close = self.close_save_dialog_window();
                 let i = self.active_tab;
+                self.tabs[i].scene.document.header.user_real1 = self.tabs[i].scene.annotation_scale as f64;
                 match crate::io::save_as_version(&self.tabs[i].scene.document, &path, version) {
                     Ok(()) => {
                         self.command_line.push_output(&format!("Saved: {}", path.display()));
@@ -2019,6 +2023,23 @@ impl H7CAD {
                 self.ortho_mode = false;
                 Task::none()
             }
+            Message::SetAnnotationScale(scale) => {
+                self.scale_popup_open = false;
+                if let Some(tab) = self.tabs.get_mut(self.active_tab) {
+                    tab.scene.annotation_scale = scale;
+                    tab.scene.bump_geometry();
+                }
+                Task::none()
+            }
+            Message::SetViewportScale(scale) => {
+                self.scale_popup_open = false;
+                if let Some(tab) = self.tabs.get_mut(self.active_tab) {
+                    tab.scene.set_viewport_scale(scale);
+                }
+                Task::none()
+            }
+            Message::ToggleScalePopup => { self.scale_popup_open ^= true; Task::none() }
+            Message::CloseScalePopup => { self.scale_popup_open = false; Task::none() }
             Message::ToggleSnap(t) => { self.snapper.toggle(t); Task::none() }
             Message::ToggleSnapPopup => { self.snap_popup_open ^= true; Task::none() }
             Message::CloseSnapPopup => { self.snap_popup_open = false; Task::none() }

src/app/view.rs

@@ -344,23 +344,32 @@ impl H7CAD {
             }
             col.push(center_stack)
                .push(self.command_line.view())
-               .push(self.status_bar.view(
-                    &self.snapper,
-                    self.snap_popup_open,
-                    self.ortho_mode,
-                    self.polar_mode,
-                    self.polar_increment_deg,
-                    self.show_grid,
-                    self.dyn_input,
-                    self.snapper.otrack_enabled,
-                    tab.scene.layout_names(),
-                    tab.scene.current_layout.clone(),
-                    self.layout_rename_state.as_ref(),
-                    tab.scene.first_viewport_scale(),
-                    tab.scene.viewport_count(),
-                    tab.scene.active_viewport.is_some(),
-                    self.show_layout_tabs,
-               ))
+               .push({
+                    let is_model = tab.scene.current_layout == "Model";
+                    let scale_pill_enabled = is_model
+                        || tab.scene.active_viewport.is_some()
+                        || tab.scene.has_selected_viewport();
+                    self.status_bar.view(
+                        &self.snapper,
+                        self.snap_popup_open,
+                        self.ortho_mode,
+                        self.polar_mode,
+                        self.polar_increment_deg,
+                        self.show_grid,
+                        self.dyn_input,
+                        self.snapper.otrack_enabled,
+                        tab.scene.layout_names(),
+                        tab.scene.current_layout.clone(),
+                        self.layout_rename_state.as_ref(),
+                        tab.scene.first_viewport_scale(),
+                        tab.scene.viewport_count(),
+                        tab.scene.active_viewport.is_some(),
+                        self.show_layout_tabs,
+                        tab.scene.annotation_scale,
+                        self.scale_popup_open,
+                        scale_pill_enabled,
+                    )
+               })
                .width(Fill)
                .height(Fill)
         })
@@ -377,6 +386,17 @@ impl H7CAD {
             iced::widget::Space::new().width(0).height(0).into()
         };
 
+        let scale_layer: Element<'_, Message> = if self.scale_popup_open {
+            let is_model = tab.scene.current_layout == "Model";
+            crate::ui::scale_popup::scale_popup_overlay(
+                is_model,
+                tab.scene.annotation_scale,
+                tab.scene.first_viewport_scale(),
+            )
+        } else {
+            iced::widget::Space::new().width(0).height(0).into()
+        };
+
         let dropdown_layer: Element<'_, Message> = self
             .ribbon
             .dropdown_overlay(
@@ -406,7 +426,7 @@ impl H7CAD {
             }
         };
 
-        stack![main_ui, self.app_menu.view(), snap_layer, dropdown_layer, layout_ctx_layer, viewport_ctx_layer].into()
+        stack![main_ui, self.app_menu.view(), snap_layer, scale_layer, dropdown_layer, layout_ctx_layer, viewport_ctx_layer].into()
     }
 
     pub fn subscription(&self) -> Subscription<Message> {