fix(section): align live section wireframe and grips

src/entities/extended.rs

@@ -20,6 +20,11 @@ use crate::scene::model::wire_model::SnapHint;
 const NAN: [f64; 3] = [f64::NAN; 3];
 const SECTION_SLICE_APP: &str = "IsSlice";
 const SECTION_THICKNESS_APP: &str = "ThicknessDepth";
+const SECTION_GRIP_LEFT: usize = 100_000;
+const SECTION_GRIP_RIGHT: usize = 100_001;
+const SECTION_GRIP_TOP: usize = 100_002;
+const SECTION_GRIP_BOTTOM: usize = 100_003;
+const SECTION_GRIP_NORMAL: usize = 100_004;
 
 pub(crate) fn section_is_slice(entity: &ExtendedEntity) -> bool {
     entity
@@ -1563,15 +1568,43 @@ fn move_extents(
 
 fn grips(entity: &ExtendedEntity) -> Vec<GripDef> {
     match &entity.data {
-        ExtendedEntityData::SectionObject(data) => data
-            .vertices
-            .iter()
-            .chain(data.back_line_vertices.iter())
-            .enumerate()
-            .map(|(index, point)| {
-                square_grip(index, glam::DVec3::new(point.x, point.y, point.z))
-            })
-            .collect(),
+        ExtendedEntityData::SectionObject(data) => {
+            let mut grips: Vec<GripDef> = if section_kind(entity, data) == "Plane"
+                && data.vertices.len() == 2
+                && data.back_line_vertices.is_empty()
+            {
+                section_plane_edge_grips(data)
+            } else {
+                data.vertices
+                    .iter()
+                    .chain(data.back_line_vertices.iter())
+                    .enumerate()
+                    .map(|(index, point)| {
+                        square_grip(index, glam::DVec3::new(point.x, point.y, point.z))
+                    })
+                    .collect()
+            };
+            if let Some(center) = section_center(data) {
+                let normal = section_viewing_direction(data);
+                let span = data
+                    .vertices
+                    .first()
+                    .zip(data.vertices.last())
+                    .map_or(1.0, |(first, last)| (*last - *first).length());
+                let offset = (span * 0.08).max(1.0e-6);
+                let normal_world = glam::DVec3::new(normal.x, normal.y, normal.z);
+                grips.push(GripDef {
+                    id: SECTION_GRIP_NORMAL,
+                    world: glam::DVec3::new(center.x, center.y, center.z)
+                        + normal_world * offset,
+                    is_midpoint: false,
+                    shape: crate::scene::model::object::GripShape::Triangle,
+                    dir: Some(normal_world),
+                    axis: Some(normal_world),
+                });
+            }
+            grips
+        }
         ExtendedEntityData::ArcAlignedText(data) => vec![center_grip(
             0,
             glam::DVec3::new(data.center.x, data.center.y, data.center.z),
@@ -1643,7 +1676,41 @@ fn grips(entity: &ExtendedEntity) -> Vec<GripDef> {
 fn apply_grip(entity: &mut ExtendedEntity, grip_id: usize, apply: GripApply) {
     match &mut entity.data {
         ExtendedEntityData::SectionObject(data) => {
-            if grip_id < data.vertices.len() {
+            if matches!(
+                grip_id,
+                SECTION_GRIP_LEFT
+                    | SECTION_GRIP_RIGHT
+                    | SECTION_GRIP_TOP
+                    | SECTION_GRIP_BOTTOM
+            ) {
+                apply_section_plane_edge_grip(data, grip_id, apply);
+            } else if grip_id == SECTION_GRIP_NORMAL {
+                let Some(center) = section_center(data) else {
+                    return;
+                };
+                let normal = section_viewing_direction(data);
+                let span = data
+                    .vertices
+                    .first()
+                    .zip(data.vertices.last())
+                    .map_or(1.0, |(first, last)| (*last - *first).length());
+                let offset = (span * 0.08).max(1.0e-6);
+                let current = center + normal * offset;
+                let delta = match apply {
+                    GripApply::Translate(delta) => Vector3::new(delta.x, delta.y, delta.z),
+                    GripApply::Absolute(position) => {
+                        Vector3::new(position.x, position.y, position.z) - current
+                    }
+                };
+                let constrained = normal * delta.dot(&normal);
+                for point in data
+                    .vertices
+                    .iter_mut()
+                    .chain(data.back_line_vertices.iter_mut())
+                {
+                    *point = *point + constrained;
+                }
+            } else if grip_id < data.vertices.len() {
                 apply_point(&mut data.vertices[grip_id], apply);
             } else if let Some(point) = data
                 .back_line_vertices
@@ -1704,6 +1771,109 @@ fn apply_grip(entity: &mut ExtendedEntity, grip_id: usize, apply: GripApply) {
     }
 }
 
+fn section_center(data: &SectionObjectData) -> Option<Vector3> {
+    let (first, last) = data.vertices.first().zip(data.vertices.last())?;
+    Some((*first + *last) * 0.5)
+}
+
+fn section_plane_edge_grips(data: &SectionObjectData) -> Vec<GripDef> {
+    let Some((first, last)) = data.vertices.first().zip(data.vertices.last()) else {
+        return Vec::new();
+    };
+    let center = (*first + *last) * 0.5;
+    let tangent = section_tangent(data);
+    let vertical = normalized(data.vertical_direction, Vector3::UNIT_Z);
+    let edge_center_offset = (data.top_height - data.bottom_height) * 0.5;
+    let definitions = [
+        (
+            SECTION_GRIP_LEFT,
+            *first + vertical * edge_center_offset,
+            vertical,
+            tangent,
+        ),
+        (
+            SECTION_GRIP_RIGHT,
+            *last + vertical * edge_center_offset,
+            vertical,
+            tangent,
+        ),
+        (
+            SECTION_GRIP_TOP,
+            center + vertical * data.top_height,
+            tangent,
+            vertical,
+        ),
+        (
+            SECTION_GRIP_BOTTOM,
+            center - vertical * data.bottom_height,
+            tangent,
+            vertical,
+        ),
+    ];
+    definitions
+        .into_iter()
+        .map(|(id, world, edge, axis)| GripDef {
+            id,
+            world: glam::DVec3::new(world.x, world.y, world.z),
+            is_midpoint: false,
+            shape: crate::scene::model::object::GripShape::Rectangle,
+            dir: Some(glam::DVec3::new(edge.x, edge.y, edge.z)),
+            axis: Some(glam::DVec3::new(axis.x, axis.y, axis.z)),
+        })
+        .collect()
+}
+
+fn apply_section_plane_edge_grip(
+    data: &mut SectionObjectData,
+    grip_id: usize,
+    apply: GripApply,
+) {
+    let Some((first, last)) = data.vertices.first().zip(data.vertices.last()) else {
+        return;
+    };
+    let center = (*first + *last) * 0.5;
+    let tangent = section_tangent(data);
+    let vertical = normalized(data.vertical_direction, Vector3::UNIT_Z);
+    let edge_center_offset = (data.top_height - data.bottom_height) * 0.5;
+    let current = match grip_id {
+        SECTION_GRIP_LEFT => *first + vertical * edge_center_offset,
+        SECTION_GRIP_RIGHT => *last + vertical * edge_center_offset,
+        SECTION_GRIP_TOP => center + vertical * data.top_height,
+        SECTION_GRIP_BOTTOM => center - vertical * data.bottom_height,
+        _ => return,
+    };
+    let delta = match apply {
+        GripApply::Translate(delta) => Vector3::new(delta.x, delta.y, delta.z),
+        GripApply::Absolute(position) => {
+            Vector3::new(position.x, position.y, position.z) - current
+        }
+    };
+    let span = (*last - *first).length();
+    let minimum_span = 1.0e-6;
+    match grip_id {
+        SECTION_GRIP_LEFT => {
+            let change = delta
+                .dot(&tangent)
+                .min((span - minimum_span).max(0.0));
+            data.vertices[0] = data.vertices[0] + tangent * change;
+        }
+        SECTION_GRIP_RIGHT => {
+            let last = data.vertices.len() - 1;
+            let change = delta
+                .dot(&tangent)
+                .max((-span + minimum_span).min(0.0));
+            data.vertices[last] = data.vertices[last] + tangent * change;
+        }
+        SECTION_GRIP_TOP => {
+            data.top_height = (data.top_height + delta.dot(&vertical)).max(0.0);
+        }
+        SECTION_GRIP_BOTTOM => {
+            data.bottom_height = (data.bottom_height - delta.dot(&vertical)).max(0.0);
+        }
+        _ => {}
+    }
+}
+
 fn entity_transform(transform: &EntityTransform) -> Transform {
     match transform {
         EntityTransform::Translate(delta) => {

src/scene/mod.rs

@@ -5410,8 +5410,12 @@ impl Scene {
         // changed entities into it, instead of re-cloning + re-sorting the whole
         // set. Falls back to the full build below when it can't (no cache entry,
         // journal un-replayable, or a structural assumption violated).
-        if let Some(arc) =
-            self.try_resident_patch(
+        // A live section changes the displayed wires of every intersected
+        // solid, even when the delta journal contains only the section entity.
+        // Rebuild the resident set in that case so an incremental patch cannot
+        // retain the source solid's uncut edge cache.
+        if self.active_live_section(block).is_none() {
+            if let Some(arc) = self.try_resident_patch(
                 key,
                 block,
                 bg,
@@ -5420,9 +5424,9 @@ impl Scene {
                 all_visible,
                 frozen_layers,
                 style_viewport,
-            )
-        {
-            return arc;
+            ) {
+                return arc;
+            }
         }
         // Build once: full tessellation, no cull, no zoom LOD — the resident
         // set is zoom-independent (GPU analytical circles/arcs/ellipses).
@@ -6996,6 +7000,48 @@ impl Scene {
         Self::section_body(&body, &section.data, section.slice_depth, None)
     }
 
+    /// Build a temporary entity whose wire data matches the live-section body.
+    /// The document entity stays unchanged so disabling the section restores
+    /// the complete source geometry and saving never persists the clipped body.
+    fn sectioned_wire_entity(
+        &self,
+        handle: Handle,
+        section: &LiveSection,
+    ) -> Result<Option<EntityType>, ()> {
+        let Some(body) = self.sectioned_body(handle, section)? else {
+            return Ok(None);
+        };
+        let (_, wires, center) = self
+            .prepare_solid_model_display(handle, &body)
+            .ok_or(())?;
+        let mut entity = self.document.get_entity(handle).cloned().ok_or(())?;
+        let reference = acadrust::types::Vector3::new(center[0], center[1], center[2]);
+        match &mut entity {
+            EntityType::Solid3D(solid) => {
+                solid.point_of_reference = reference;
+                solid.wires = wires;
+                solid.silhouettes.clear();
+            }
+            EntityType::Surface(surface) => {
+                surface.point_of_reference = reference;
+                surface.wires = wires;
+                surface.silhouettes.clear();
+            }
+            EntityType::Region(region) => {
+                region.point_of_reference = reference;
+                region.wires = wires;
+                region.silhouettes.clear();
+            }
+            EntityType::Body(body) => {
+                body.point_of_reference = reference;
+                body.wires = wires;
+                body.silhouettes.clear();
+            }
+            _ => return Err(()),
+        }
+        Ok(Some(entity))
+    }
+
     fn section_source_body(
         &self,
         handle: Handle,
@@ -9709,6 +9755,45 @@ impl Scene {
             memo_misses = visible_count;
             out
         };
+
+        // Normal Wireframe renders the persisted entity wires, whereas shaded
+        // and 3D Wireframe modes render the temporary sectioned mesh. Replace
+        // only the displayed wire run with one tessellated from that same
+        // temporary body so every visual style shows the identical live cut.
+        if let Some(section) = self.active_live_section(block_handle) {
+            let handles: Vec<Handle> = self.meshes.keys().copied().collect();
+            for handle in handles {
+                let Some(source) = self.document.get_entity(handle) else {
+                    continue;
+                };
+                if !visibility_ok(source) {
+                    continue;
+                }
+                let replacement = match self.sectioned_wire_entity(handle, &section) {
+                    Ok(Some(entity)) => Some(tessellate_entity(
+                        doc,
+                        sel,
+                        avp,
+                        bg,
+                        anno,
+                        annotation_scale_handle,
+                        &entity,
+                        Some(blk_ref),
+                        view_aabb,
+                        wpp,
+                        paper,
+                    )),
+                    Ok(None) => Some(Vec::new()),
+                    Err(()) => None,
+                };
+                let Some(replacement) = replacement else {
+                    continue;
+                };
+                let name = handle.value().to_string();
+                wires.retain(|wire| wire.name != name);
+                wires.extend(replacement);
+            }
+        }
         let build_ms = crate::perf::elapsed_ms(t_build);
 
         // Resolve display colours for the live background. Memo hits were