Keep rotation angle label on guide arc

src/app/view/mod.rs

@@ -836,6 +836,25 @@ impl OpenCADStudio {
             {
                 let w = tab.last_cursor_world;
                 let base = tab.dyn_anchor.or(self.last_point);
+                let label_screen = tab
+                    .active_cmd
+                    .as_ref()
+                    .and_then(|command| command.dyn_label_point(w))
+                    .and_then(|world| {
+                        let (vw, vh) = tab.scene.selection.borrow().vp_size;
+                        let (camera, bounds) = tab
+                            .scene
+                            .viewport_edit_frame((vw, vh))
+                            .unwrap_or_else(|| {
+                                (
+                                    tab.scene.camera.borrow().clone(),
+                                    tab.scene.active_model_tile_bounds(vw, vh),
+                                )
+                            });
+                        camera.project(world, bounds).map(|point| {
+                            iced::Point::new(bounds.x + point.x, bounds.y + point.y)
+                        })
+                    });
                 // A command may drive a typed scalar by mouse (e.g. a
                 // perpendicular distance to a picked object); show that live
                 // value in the box until the user types over it.
@@ -898,6 +917,7 @@ impl OpenCADStudio {
                     tab.last_cursor_screen,
                     tab.last_point_screen,
                     tab.dyn_ref_screen,
+                    label_screen,
                     tab.dyn_guide,
                     boxes,
                     prompt,

src/command.rs

@@ -2179,6 +2179,12 @@ pub trait CadCommand: Send {
     fn dyn_live_value(&self, _cursor: DVec3) -> Option<f64> {
         None
     }
+
+    /// Optional world-space point where the dynamic value box should be
+    /// centred. The view projects it with the active camera.
+    fn dyn_label_point(&self, _cursor: DVec3) -> Option<DVec3> {
+        None
+    }
 }
 
 // ── Autocomplete registry ─────────────────────────────────────────────────

src/modules/draw/modify/rotate.rs

@@ -73,6 +73,19 @@ impl RotateCommand {
         )
     }
 
+    fn angle_arc(
+        center: [f64; 2],
+        radius: f64,
+        angle: f64,
+    ) -> Option<(geom2d::Arc, bool)> {
+        let (start, end, reverse) = if angle > 0.0 {
+            (0.0, angle, false)
+        } else {
+            (angle, 0.0, true)
+        };
+        geom2d::bounded_arc(center, radius, start, end).map(|arc| (arc, reverse))
+    }
+
     fn angle_guide(&self, center: DVec3, radius: f64, angle: f64) -> Vec<WireModel> {
         if radius <= f64::EPSILON {
             return vec![];
@@ -95,13 +108,11 @@ impl RotateCommand {
             return guides;
         }
 
-        let (start, end, reverse) = if angle > 0.0 {
-            (0.0, angle, false)
-        } else {
-            (angle, 0.0, true)
-        };
-        let Some(arc) = geom2d::bounded_arc([center_local.x, center_local.y], radius, start, end)
-        else {
+        let Some((arc, reverse)) = Self::angle_arc(
+            [center_local.x, center_local.y],
+            radius,
+            angle,
+        ) else {
             return guides;
         };
         let mut points = KernelCurve::Arc(arc).tessellate_angle(TAU / 64.0);
@@ -327,4 +338,54 @@ impl CadCommand for RotateCommand {
             _ => None,
         }
     }
+
+    fn dyn_label_point(&self, cursor: DVec3) -> Option<DVec3> {
+        let center = match self.step {
+            Step::Angle { center } | Step::RefNew { center, .. } => center,
+            _ => return None,
+        };
+        let center_local = self.plane.to_local(center);
+        let direction = self.plane.vector_to_local(cursor - center);
+        let radius = direction.truncate().length();
+        if radius <= f64::EPSILON {
+            return None;
+        }
+        let angle = direction.y.atan2(direction.x);
+        let point = if angle.abs() <= f64::EPSILON {
+            [center_local.x + radius, center_local.y]
+        } else {
+            let (arc, _) = Self::angle_arc(
+                [center_local.x, center_local.y],
+                radius,
+                angle,
+            )?;
+            KernelCurve::Arc(arc).point_at(0.5)
+        };
+        Some(
+            self.plane
+                .to_world(DVec3::new(point[0], point[1], center_local.z)),
+        )
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn angle_label_uses_the_working_plane_arc_midpoint() {
+        let plane = WorkingPlane::new(DVec3::ZERO, DVec3::Y, DVec3::Z);
+        let mut command = RotateCommand::new(vec![], vec![]);
+        command.set_working_plane(plane);
+        command.step = Step::Angle {
+            center: DVec3::ZERO,
+        };
+
+        let label = command
+            .dyn_label_point(plane.y * 10.0)
+            .expect("label point");
+        let expected = (plane.x + plane.y) * (50.0_f64).sqrt();
+
+        assert!(label.abs_diff_eq(expected, 1e-9));
+    }
 }

src/ui/overlay.rs

@@ -2301,6 +2301,7 @@ pub fn dynamic_input_overlay<'a>(
     cursor_screen: Point,
     base_screen: Option<Point>,
     ref_screen: Option<Point>,
+    label_screen: Option<Point>,
     guide: DynGuide,
     boxes: Vec<DynBox>,
     prompt: String,
@@ -2310,6 +2311,7 @@ pub fn dynamic_input_overlay<'a>(
         cursor_screen,
         base_screen,
         ref_screen,
+        label_screen,
         guide,
         boxes,
         prompt,
@@ -2327,6 +2329,8 @@ struct DynInputCanvas {
     base_screen: Option<Point>,
     /// Far end of the reference line (projected `dyn_ref`) — for `Perp`.
     ref_screen: Option<Point>,
+    /// Command-supplied world-space label point projected by the active camera.
+    label_screen: Option<Point>,
     guide: DynGuide,
     boxes: Vec<DynBox>,
     /// The active command's current prompt, drawn just above the boxes.
@@ -2359,21 +2363,6 @@ impl DynInputCanvas {
         (Self::box_content(b).len() as f32 * DYN_CHAR_W) + DYN_PAD * 2.0
     }
 
-    fn box_center_near_cursor(b: &DynBox, cursor: Point, bounds: iced::Rectangle) -> Point {
-        let width = Self::box_width(b);
-        let x = if cursor.x + DYN_OFFSET_X + width <= bounds.width {
-            cursor.x + DYN_OFFSET_X + width * 0.5
-        } else {
-            cursor.x - DYN_OFFSET_X - width * 0.5
-        };
-        let y = if cursor.y + DYN_OFFSET_X + DYN_BOX_H <= bounds.height {
-            cursor.y + DYN_OFFSET_X + DYN_BOX_H * 0.5
-        } else {
-            cursor.y - DYN_OFFSET_X - DYN_BOX_H * 0.5
-        };
-        Point { x, y }
-    }
-
     /// Draw a value box centred at `center`, clamped inside `bounds`.
     fn draw_box(
         frame: &mut canvas::Frame,
@@ -2660,7 +2649,14 @@ impl DynInputCanvas {
         // ── Box placement by role ──
         for b in &self.boxes {
             let center = match b.role {
-                DynRole::Angle => Self::box_center_near_cursor(b, cursor_raw, bounds),
+                DynRole::Angle => self.label_screen.unwrap_or_else(|| {
+                    let a_mid = a_ref + sweep * 0.5;
+                    let r = (len - DYN_BOX_H * 2.0).max(len * 0.5);
+                    Point {
+                        x: base.x + a_mid.cos() * r - nx * 18.0,
+                        y: base.y + a_mid.sin() * r - ny * 18.0,
+                    }
+                }),
                 DynRole::X | DynRole::Width => Point {
                     x: (base.x + cursor.x) * 0.5,
                     y: base.y + 14.0,
@@ -2854,6 +2850,9 @@ impl canvas::Program<Message> for DynInputCanvas {
 
         // Guided layouts need the anchor; without it fall back to a cursor row.
         match (self.guide, self.base_screen) {
+            (DynGuide::None, Some(base)) if self.label_screen.is_some() => {
+                self.draw_guided(&mut frame, bounds, base, theme)
+            }
             (DynGuide::None, _) | (_, None) => self.draw_row(&mut frame, bounds, theme),
             (_, Some(base)) => self.draw_guided(&mut frame, bounds, base, theme),
         }
@@ -2861,40 +2860,6 @@ impl canvas::Program<Message> for DynInputCanvas {
     }
 }
 
-#[cfg(test)]
-mod dynamic_input_position_tests {
-    use super::*;
-
-    #[test]
-    fn angle_box_follows_cursor_and_flips_inside_viewport_edges() {
-        let angle = DynBox {
-            label: String::new(),
-            value: "163.7".to_string(),
-            active: true,
-            locked: false,
-            role: DynRole::Angle,
-        };
-        let bounds = iced::Rectangle {
-            x: 0.0,
-            y: 0.0,
-            width: 800.0,
-            height: 600.0,
-        };
-        let width = DynInputCanvas::box_width(&angle);
-
-        let cursor = Point::new(400.0, 300.0);
-        let center = DynInputCanvas::box_center_near_cursor(&angle, cursor, bounds);
-        assert!((center.x - width * 0.5 - cursor.x - DYN_OFFSET_X).abs() < 0.01);
-        assert!((center.y - DYN_BOX_H * 0.5 - cursor.y - DYN_OFFSET_X).abs() < 0.01);
-
-        let cursor = Point::new(795.0, 595.0);
-        let center = DynInputCanvas::box_center_near_cursor(&angle, cursor, bounds);
-        assert!(center.x + width * 0.5 <= bounds.width);
-        assert!(center.y + DYN_BOX_H * 0.5 <= bounds.height);
-        assert!(center.x < cursor.x && center.y < cursor.y);
-    }
-}
-
 #[cfg(test)]
 mod clip_tests {
     use super::*;