fix(3d): move and paste ACIS solids to the right place

Solids were missing from the entity transform dispatch, so move / rotate /
scale / mirror were silently no-ops on a 3D solid (only its wires shifted)
and a pasted solid stayed at its original location. Add a Transformable impl
for Solid3D/Region/Body/Surface (delegating to acadrust, which now composes
the move into the ACIS body placement) and register them in the dispatcher.

Also make cross-drawing paste land at the cursor: the clipboard centroid is
measured in the source drawing's offset-relative frame, so correct the paste
translation by the source/target world_offset difference (zero within one
drawing). Bumps acadrust for the solid-geometry transform fixes.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

Cargo.lock

@@ -70,7 +70,7 @@ checksum = "366ffbaa4442f4684d91e2cd7c5ea7c4ed8add41959a31447066e279e432b618"
 [[package]]
 name = "acadrust"
 version = "0.3.4"
-source = "git+https://github.com/HakanSeven12/acadrust?branch=main#33cb8b72dbf9f3dc585619a31848b42c5acf8c81"
+source = "git+https://github.com/HakanSeven12/acadrust?branch=main#07006d104150006332d2873413afba9620cf0aa3"
 dependencies = [
  "ahash",
  "anyhow",

src/app/cmd_result.rs

@@ -594,7 +594,19 @@ impl OpenCADStudio {
                 if self.clipboard.is_empty() {
                     self.command_line.push_error("Clipboard is empty.");
                 } else {
-                    let delta = base_pt - self.clipboard_centroid;
+                    // The centroid was measured in the source drawing's
+                    // offset-relative frame and `base_pt` is in this drawing's;
+                    // correct by the world_offset difference so a cross-drawing
+                    // paste lands at the cursor instead of drifting by the
+                    // offset gap. Zero for a same-drawing paste. (#135)
+                    let src_wo = self.clipboard_world_offset;
+                    let tgt_wo = self.tabs[i].scene.world_offset;
+                    let wo_corr = glam::Vec3::new(
+                        (tgt_wo[0] - src_wo[0]) as f32,
+                        (tgt_wo[1] - src_wo[1]) as f32,
+                        (tgt_wo[2] - src_wo[2]) as f32,
+                    );
+                    let delta = base_pt - self.clipboard_centroid + wo_corr;
                     let translate = crate::command::EntityTransform::Translate(delta);
                     self.push_undo_snapshot(i, "PASTECLIP");
                     // Recreate any layer / linetype / style the copied entities

src/app/commands.rs

@@ -540,6 +540,7 @@ impl OpenCADStudio {
                     self.clipboard_centroid = super::helpers::entities_centroid(
                         &self.tabs[i].scene.wire_models_for(&handles),
                     );
+                    self.clipboard_world_offset = self.tabs[i].scene.world_offset;
                     self.clipboard = entities;
                     self.clipboard_deps = super::ClipboardDeps::capture(
                         &self.tabs[i].scene.document,
@@ -572,6 +573,7 @@ impl OpenCADStudio {
                     self.clipboard_centroid = super::helpers::entities_centroid(
                         &self.tabs[i].scene.wire_models_for(&handles),
                     );
+                    self.clipboard_world_offset = self.tabs[i].scene.world_offset;
                     let count = entities.len();
                     self.clipboard = entities;
                     self.clipboard_deps = super::ClipboardDeps::capture(

src/app/mod.rs

@@ -369,6 +369,12 @@ pub(super) struct OpenCADStudio {
     clipboard: Vec<acadrust::EntityType>,
     /// Centroid of the clipboard entities (world XY plane).
     clipboard_centroid: glam::Vec3,
+    /// The source drawing's `world_offset` at copy time. The centroid above is
+    /// measured in that drawing's offset-relative frame; pasting into a drawing
+    /// with a different offset (e.g. a large-coordinate file → a fresh one)
+    /// must correct the paste translation by the offset difference, else the
+    /// objects land `source_offset − target_offset` away from the cursor.
+    clipboard_world_offset: [f64; 3],
     /// Table records (layer / linetype / text + dim style) the clipboard
     /// entities reference, captured from the source drawing at copy time so a
     /// paste into a *different* drawing can recreate any that are missing —
@@ -1721,6 +1727,7 @@ impl OpenCADStudio {
             update_notice_body: None,
             clipboard: Vec::new(),
             clipboard_centroid: glam::Vec3::ZERO,
+            clipboard_world_offset: [0.0; 3],
             clipboard_deps: ClipboardDeps::default(),
             shift_down: false,
             mtext_editor: None,

src/entities/solid3d.rs

@@ -6,13 +6,36 @@
 // fallback stays in sync; the caller (scene/mod.rs apply_grip) translates
 // the MeshModel vertices to match.
 
-use acadrust::entities::{Body, Region, Solid3D};
+use acadrust::entities::{Body, Region, Solid3D, Surface};
 use glam::Vec3;
 
+use crate::command::EntityTransform;
 use crate::entities::common::{center_grip, ro_prop as ro};
-use crate::entities::traits::{Grippable, PropertyEditable};
+use crate::entities::traits::{Grippable, PropertyEditable, Transformable};
 use crate::scene::model::object::{GripApply, GripDef, PropSection};
 
+/// Shared transform for the ACIS volume entities. Translate / rotate / scale
+/// delegate to acadrust (which composes the move into the solid's ACIS
+/// placement), and mirror delegates via a reflection transform. Without this
+/// the entity dispatcher treated solids as non-transformable, so a moved or
+/// pasted solid stayed at its original ACIS placement.
+macro_rules! impl_acis_transformable {
+    ($ty:ty) => {
+        impl Transformable for $ty {
+            fn apply_transform(&mut self, t: &EntityTransform) {
+                crate::scene::view::transform::apply_standard_entity_transform(self, t, |e, p1, p2| {
+                    let m = crate::scene::view::transform::reflection_about_xy_line(p1, p2);
+                    acadrust::Entity::apply_transform(e, &m);
+                });
+            }
+        }
+    };
+}
+impl_acis_transformable!(Solid3D);
+impl_acis_transformable!(Region);
+impl_acis_transformable!(Body);
+impl_acis_transformable!(Surface);
+
 // ── shared helpers ────────────────────────────────────────────────────────────
 
 fn dvec3(v: &acadrust::types::Vector3) -> glam::DVec3 {

src/entities/traits.rs

@@ -422,6 +422,7 @@ impl EntityTypeOps for EntityType {
                 Tolerance, Solid, Face3D, PolygonMesh, PolyfaceMesh, Mesh,
                 Table, MText, Point, Spline, Text, Viewport, Dimension,
                 Leader, MultiLeader, Underlay, Shape, Ole2Frame,
+                Solid3D, Region, Body, Surface,
             ],
             _ => {},
         )