fix: NAVVCUBE and UCSICON commands now properly toggle visibility

NAVVCUBE: propagate show_viewcube flag through ViewportPane and the wgpu
Primitive so the ViewCube pipeline skips upload/render when hidden.
UCSICON: bare command (no subcommand) now toggles current state instead
of printing usage info.

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

src/scene/render.rs

@@ -88,6 +88,7 @@ pub struct Primitive {
     pub(super) hover_region: Option<usize>,
     /// Background color used to clear the MSAA buffer at the start of each frame.
     pub(super) bg_color: [f32; 4],
+    pub(super) show_viewcube: bool,
 }
 
 // ── shader::Primitive impl ────────────────────────────────────────────────
@@ -120,13 +121,15 @@ impl shader::Primitive for Primitive {
         pipeline.upload_images(device, queue, &self.images);
         pipeline.upload_meshes(device, &self.meshes);
         pipeline.upload_wires(device, &self.wires);
-        pipeline.viewcube.upload(
-            queue,
-            self.cam_rotation,
-            bounds.width as u32,
-            bounds.height as u32,
-            self.hover_region,
-        );
+        if self.show_viewcube {
+            pipeline.viewcube.upload(
+                queue,
+                self.cam_rotation,
+                bounds.width as u32,
+                bounds.height as u32,
+                self.hover_region,
+            );
+        }
     }
 
     fn render(
@@ -137,7 +140,9 @@ impl shader::Primitive for Primitive {
         clip: &Rectangle<u32>,
     ) {
         pipeline.render(encoder, target, *clip, self.bg_color);
-        pipeline.viewcube.render(encoder, target, *clip);
+        if self.show_viewcube {
+            pipeline.viewcube.render(encoder, target, *clip);
+        }
     }
 }
 
@@ -216,6 +221,7 @@ impl Scene {
         &self,
         hover_region: Option<usize>,
         bounds: Rectangle,
+        show_viewcube: bool,
     ) -> Primitive {
         let cam = self.camera.borrow();
         self.selection.borrow_mut().vp_size = (bounds.width, bounds.height);
@@ -242,6 +248,7 @@ impl Scene {
             cam_rotation: cam.view_rotation_mat(),
             hover_region,
             bg_color,
+            show_viewcube,
         }
     }
 
@@ -256,7 +263,7 @@ impl Scene {
     ) -> Primitive {
         let cam = match self.camera_for_viewport(vp_handle) {
             Some(c) => c,
-            None => return self.build_primitive(hover_region, bounds),
+            None => return self.build_primitive(hover_region, bounds, false),
         };
 
         let mut all_wires = self.model_wires_for_viewport(vp_handle);
@@ -275,6 +282,7 @@ impl Scene {
             cam_rotation: cam.view_rotation_mat(),
             hover_region,
             bg_color: self.bg_color,
+            show_viewcube: false,
         }
     }
 

src/scene/viewport_pane.rs

@@ -25,18 +25,19 @@ pub enum ViewportPaneMode {
 pub struct ViewportPane<'a> {
     pub scene: &'a Scene,
     pub mode: ViewportPaneMode,
+    pub show_viewcube: bool,
 }
 
 impl<'a> ViewportPane<'a> {
-    pub fn model(scene: &'a Scene) -> Self {
-        Self { scene, mode: ViewportPaneMode::Model }
+    pub fn model(scene: &'a Scene, show_viewcube: bool) -> Self {
+        Self { scene, mode: ViewportPaneMode::Model, show_viewcube }
     }
 
     /// One paper-space viewport: model content rendered through its own camera.
     /// See [`ViewportPaneMode::Paper`] for why this is currently unused.
     #[allow(dead_code)]
     pub fn paper(scene: &'a Scene, handle: Handle) -> Self {
-        Self { scene, mode: ViewportPaneMode::Paper { handle } }
+        Self { scene, mode: ViewportPaneMode::Paper { handle }, show_viewcube: false }
     }
 }
 
@@ -106,7 +107,7 @@ impl<'a, Msg: std::fmt::Debug + Clone> shader::Program<Msg> for ViewportPane<'a>
     ) -> Self::Primitive {
         match &self.mode {
             ViewportPaneMode::Model => {
-                self.scene.build_primitive(state.hover_region, bounds)
+                self.scene.build_primitive(state.hover_region, bounds, self.show_viewcube)
             }
             ViewportPaneMode::Paper { handle } => {
                 self.scene.build_viewport_primitive(*handle, state.hover_region, bounds)
@@ -122,8 +123,10 @@ impl<'a, Msg: std::fmt::Debug + Clone> shader::Program<Msg> for ViewportPane<'a>
         cursor: mouse::Cursor,
     ) -> Option<iced::widget::Action<Msg>> {
         // ViewCube hover only makes sense in the full model-space view.
-        if matches!(self.mode, ViewportPaneMode::Model) {
+        if matches!(self.mode, ViewportPaneMode::Model) && self.show_viewcube {
             self.scene.update_viewcube_state(state, bounds, cursor);
+        } else {
+            state.hover_region = None;
         }
         let _ = event;
         None
@@ -135,7 +138,7 @@ impl<'a, Msg: std::fmt::Debug + Clone> shader::Program<Msg> for ViewportPane<'a>
         _b: Rectangle,
         _c: mouse::Cursor,
     ) -> mouse::Interaction {
-        if matches!(self.mode, ViewportPaneMode::Model) {
+        if matches!(self.mode, ViewportPaneMode::Model) && self.show_viewcube {
             self.scene.viewcube_mouse_interaction(state)
         } else {
             mouse::Interaction::default()