refactor: retire the solid3d feature — the web build gets solids too

The feature existed for one reason: truck's mesh and boolean crates reach
`vtkio → xz2 → lzma-sys`, a C library that cannot cross-compile to wasm32. So
the web build dropped it, and with it the Model tab, solid tessellation and
ACIS import — all of which quietly did nothing in the browser.

cadkernel is pure Rust and has no C dependency, so none of that holds any
more. The feature gated exactly two things by the end, `acis_export` and the
save-path sync that calls it, and both are as portable as everything around
them. Removing it means the web build makes primitives, runs booleans, draws
ACIS solids read from a file, and writes them back out as exact geometry — the
same as the desktop build.

Verified against all three: native, `--no-default-features`, and an actual
`wasm32-unknown-unknown` check rather than an assumption about one.

The docs claimed otherwise in four places and are corrected. `tessellation.md`
in particular was organised around whether an entity "goes through truck",
which is no longer a question anything can be asked — the three paths are now
a kernel B-rep mesh, a curve sampled through `entities::curve`, or geometry
emitted directly, and the per-entity table is updated to match.

`index.html` no longer passes `data-cargo-no-default-features`; there are no
features left to turn off.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

.github/workflows/pages.yml

@@ -50,10 +50,8 @@ jobs:
         with:
           tool: wasm-bindgen@${{ steps.wasm-bindgen-version.outputs.version }}
 
-      # The rust <link> in index.html sets `data-cargo-no-default-features`,
-      # so this drops the `solid3d` feature (truck-meshalgo → lzma-sys C deps
-      # that can't cross-compile to wasm). `--public-url` matches the project
-      # page sub-path: https://<user>.github.io/OpenCADStudio/.
+      # `--public-url` matches the project page sub-path:
+      # https://<user>.github.io/OpenCADStudio/.
       - name: Build web bundle
         run: trunk build --release --public-url /OpenCADStudio/
 

Cargo.toml

@@ -15,10 +15,6 @@ members = [
 [target.'cfg(windows)'.build-dependencies]
 winresource = "0.1"
 
-[features]
-default = ["solid3d"]
-solid3d = []
-
 [dependencies]
 serde_json = "1"
 serde = { version = "1", features = ["derive"] }

Trunk.toml

@@ -8,9 +8,9 @@
 
 [build]
 target = "index.html"
-# Note: the `solid3d` feature is disabled via `data-cargo-no-default-features`
-# on the rust <link> in index.html (truck-meshalgo → lzma-sys C deps cannot
-# cross-compile to wasm).
+# The crate has no Cargo features: the geometry kernel is pure Rust and
+# cross-compiles to wasm, so the web build gets the same solid modelling the
+# native one does.
 
 [[hooks]]
 stage = "post_build"

docs/native-vs-web.md

@@ -10,7 +10,7 @@ browser can't provide. This page lists the differences.
 | Area | Native (desktop) | Web (wasm) |
 |------|------------------|------------|
 | Windowing | Multi-window (`iced::daemon`) | Single window (`iced::application`); dialogs are in-canvas modals |
-| 3D solid modeling | Yes | **No** — `solid3d` feature off |
+| 3D solid modeling | Yes | Yes — the geometry kernel is pure Rust |
 | Hatch rendering | Yes | **No** — WebGL2 has no vertex-stage storage |
 | Fonts | Embedded stroke fonts + system TrueType + shaping + fallback | Embedded stroke fonts only |
 | File open | Native file dialog → path | Browser picker → bytes |
@@ -22,15 +22,16 @@ browser can't provide. This page lists the differences.
 
 ## Details
 
-### 3D solid modeling — web: disabled
-The `solid3d` Cargo feature (default on) gates `truck-meshalgo` and
-`truck-shapeops`, which pull `vtkio → xz2 → lzma-sys`, a C library that can't
-cross-compile to `wasm32`. The web build compiles with `--no-default-features`,
-so on the web:
-- The Model tab's solid primitives and boolean operations are no-ops.
-- Solid tessellation and ACIS (SAT) import produce no geometry.
+### 3D solid modeling — web: the same as native
+It used to be off. The modelling kernel was truck, whose mesh and boolean
+crates reach `vtkio → xz2 → lzma-sys` — a C library that cannot cross-compile
+to `wasm32` — so the web build dropped a `solid3d` feature and the Model tab,
+solid tessellation and ACIS import all did nothing there.
 
-2-D CAD is unaffected.
+The kernel is now cadkernel, which is pure Rust and has no C dependency at
+all, so none of that applies and the feature is gone. The web build makes
+primitives, runs booleans, draws ACIS solids read from a file and writes them
+back out as exact geometry, exactly as the desktop build does.
 
 ### Hatch rendering — web: not drawn
 The batched hatch pipeline binds a read-only storage buffer in the vertex
@@ -97,8 +98,7 @@ folder and load again on the next desktop launch.
 ## Build & deploy
 
 - Native: `cargo build --release --bin OpenCADStudio`.
-- Web: `trunk build --release --public-url /OpenCADStudio/` (the rust `<link>`
-  in `index.html` sets `data-cargo-no-default-features`, dropping `solid3d`).
+- Web: `trunk build --release --public-url /OpenCADStudio/`.
   `.github/workflows/pages.yml` builds and deploys to GitHub Pages on every
   release. No COOP/COEP headers are needed because the web build is
   single-threaded.

docs/tessellation.md

@@ -1,45 +1,50 @@
 # Entity tessellation paths
 
-How each acadrust `EntityType` becomes drawable geometry in OpenCADStudio, and
-whether it passes through the [truck](https://github.com/ricosjp/truck) modeling
-kernel.
+How each acadrust `EntityType` becomes drawable geometry in OpenCADStudio.
 
-There are **two distinct meanings of "through truck"** in the codebase, and they
-must not be conflated:
+There are **three ways** an entity gets there, and they must not be conflated:
 
-1. **truck B-rep meshing** — the entity is rebuilt as a truck `Shell`/`Solid`
-   and triangulated by `MeshableShape::triangulation()`. This is the only path
-   that produces filled *mesh* triangles from a kernel.
-2. **truck curve topology** — the entity is expressed as a truck `Edge`/`Wire`/
-   `Vertex` and sampled into line segments by truck's `ParameterDivision1D`. It
-   touches truck *topology* but never triangulates a surface; the output is a
-   polyline.
+1. **Kernel B-rep mesh** — the ACIS document is lifted into a cadkernel `Body`
+   and each face triangulated in its own surface's parameter space. The only
+   path that produces filled *mesh* triangles from analytic surfaces.
+2. **Curve-sampled** — the entity's geometry is read through
+   `entities::curve::entity_curve`, which is where each type's curve is defined
+   once, and tessellated to a chord tolerance. Output is a polyline; no surface
+   is involved.
+3. **Direct** — points, segments or triangles emitted straight from the
+   entity's own fields.
 
-Everything else is **direct**: points/segments/triangles are emitted straight
-from the entity's own data without any truck object.
+The distinction between (2) and (3) is worth keeping because (2) is a single
+definition shared with everything else that needs an entity's geometry — snap
+candidates, EXTRUDE and REVOLVE profiles, hatch boundaries, clip outlines. A
+circle drawn on screen and a circle handed to the Model tab come from the same
+place and cannot disagree.
 
 Entry points: `src/scene/convert/tess.rs` (`tessellate_entity`, the per-entity
-dispatcher) → `src/scene/convert/tessellate.rs` (`tessellate`, the `TruckObject`
-router) and `src/scene/convert/truck_tess.rs` (curve sampling).
+dispatcher) → `src/scene/convert/tessellate.rs` (`tessellate`, the
+`RenderObject` router), `src/entities/curve.rs` (curve definitions and
+sampling) and `src/scene/convert/curve_tol.rs` (the per-frame chord tolerance).
 
 ## Summary
 
 | Path | Entities |
 |---|---|
-| **truck B-rep mesh** (Shell → `triangulation`, with a direct per-surface fallback) | `Solid3D`, `Region`, `Body`, `Surface` |
-| **truck curve topology** (Edge/Wire → `ParameterDivision1D` sampling) | `Line`, `Arc`, `Circle`, `Ellipse`, `Spline`, `LwPolyline`, `Polyline`, `Polyline2D`, `Polyline3D`, `Point` — *non-thick variants only* |
-| **direct** (no truck — segments/triangles emitted directly) | everything else |
+| **Kernel B-rep mesh** (lift → per-face triangulation, with a direct per-surface fallback) | `Solid3D`, `Region`, `Body`, `Surface` |
+| **Curve-sampled** (`entity_curve` → chord-tolerance tessellation) | `Line`, `Arc`, `Circle`, `Ellipse`, `Spline`, `LwPolyline`, `Polyline`, `Polyline2D`, `Polyline3D` — *non-thick variants only* |
+| **Direct** (segments/triangles emitted straight) | everything else |
 
 > The Model/Design-tab primitives (BOX, SPHERE, CYLINDER, CONE, WEDGE, TORUS,
-> PYRAMID, extrude/revolve/loft/sweep) are also true truck B-rep meshes
-> (`truck_tess::tessellate_solid`), but they are created as `Solid3D`
-> placeholders carrying a truck B-rep, not as their own `EntityType`.
+> PYRAMID, EXTRUDE, REVOLVE) are true kernel B-reps too, cached on the Scene as
+> `Body` and meshed the same way — but they are created as `Solid3D`
+> placeholders carrying that body, not as their own `EntityType`. SWEEP and
+> LOFT produce a mesh only, with no B-rep behind it.
 
-The only call site of `shell.triangulation()` for an imported entity is
-`acis_to_truck::tessellate_sat_truck`. The four ACIS solids dispatch through
-`solid3d_tess::tessellate_acis`, which tries that truck kernel first and falls
-back to a bespoke per-surface LOD sampler (`tessellate_sat_lods`) when truck
-cannot rebuild a face — so their path is **truck-with-direct-fallback**.
+ACIS solids dispatch through `solid3d_tess::tessellate_acis`, which lifts the
+document into the kernel first (`acis_kernel::tessellate_sat`) and falls back
+to a bespoke per-surface LOD sampler (`tessellate_sat_lods`) when the kernel
+cannot express a face — so their path is **kernel-with-direct-fallback**. The
+fallback is not silent: a mesh whose faces did not all lift is marked
+incomplete, because one missing wall looks exactly like a finished solid.
 
 Curved-surface tessellation density is radius-relative (`CURVE_REL_TOL`, a
 fraction of the surface radius) so a cylinder's facet count matches the
@@ -49,40 +54,40 @@ circle/arc wire tessellation instead of exploding on large radii.
 
 | Entity | Output | Path | Notes |
 |---|---|---|---|
-| Arc | wire | direct (truck curve topology) | non-thick: truck `Edge` (`builder::circle_arc`) sampled via `ParameterDivision1D`; thick: direct `Lines` |
+| Arc | wire | curve-sampled | non-thick: sampled from the arc's own curve; thick: direct `Lines` plus the swept wall |
 | AttributeDefinition | wire | direct | routes through the Text/MText LFF glyph stroke pipeline |
 | AttributeEntity | wire | direct | same as AttributeDefinition; values supplied per Insert |
 | Block | none | n/a | block-definition sentinel; not tessellated (referenced via Insert) |
 | BlockEnd | none | n/a | block-definition end marker; no output |
-| Body | mesh | truck-with-direct-fallback | 3D ACIS body → truck `Shell` → `triangulation`; fallback per-surface sampler |
-| Circle | wire | direct (truck curve topology) | non-thick: truck `Wire` of two half-circle edges; thick: direct `Lines` |
+| Body | mesh | kernel-with-direct-fallback | 3D ACIS body lifted into a kernel `Body`; fallback per-surface sampler |
+| Circle | wire | curve-sampled | non-thick: sampled from the circle's own curve; thick: direct `Lines` |
 | Dimension | wire | direct | baked-block path recurses on `D###` sub-entities; synthesis path emits lines/arrows/LFF text |
-| Ellipse | wire | direct (truck curve topology) | truck `Wire`/`Edge` over a `BSplineCurve`, `ParameterDivision1D` sampled |
-| Face3D | both | direct | edge `Lines` + direct fan-triangulated `fill_tris`; no truck B-rep |
+| Ellipse | wire | curve-sampled | sampled from the ellipse's own curve |
+| Face3D | both | direct | edge `Lines` + direct fan-triangulated `fill_tris`; no B-rep |
 | Hatch | both | direct | boundary outline not emitted to the wire set (#131 OOM); fill rasterized on GPU |
 | Insert | wire | direct | expands block children and tessellates each via its own path; XCLIP filter applied |
 | Leader | wire | direct | leader path + arrowhead + landing, direct `Lines` |
-| Line | wire | direct (truck curve topology) | non-thick: truck `Edge` (`builder::line`); thick: direct `Lines` |
-| LwPolyline | wire | direct (truck curve topology) | `plinegen` true: truck `Contour` with bulge arcs; else direct `SegmentedLines` |
+| Line | wire | curve-sampled | non-thick: its two ends; thick: direct `Lines` plus the swept wall |
+| LwPolyline | wire | curve-sampled | `plinegen` true: sampled from its own curve, bulges kept as arcs; else direct `SegmentedLines` |
 | Mesh | both | direct | SubD mesh: edge `Lines` + direct fan-triangulated `fill_tris` |
 | MLine | wire | direct | spine + offset lines + caps, direct `Lines` |
 | MText | wire | direct | wrap-aware multi-line LFF glyph layout; inline formatting codes |
 | MultiLeader | wire | direct | leader + landing + LFF text + frame + fill |
 | Ole2Frame | wire | direct | bounding rectangle + diagonal cross |
-| Point | wire | direct (truck topology) | truck `Vertex` → cross marker sized by PDSIZE |
+| Point | wire | direct | a position → dot or cross marker sized by PDSIZE |
 | PolyfaceMesh | both | direct | face list: closed-polyline edges + direct fan-triangulated `fill_tris` |
 | PolygonMesh | both | direct | M×N grid wireframe + direct fan-triangulated `fill_tris` |
-| Polyline | wire | direct (truck curve topology) | heavy 3D polyline; truck `Contour` + bulge arcs |
-| Polyline2D | wire | direct (truck curve topology) | 2D polyline with bulge; truck `Contour` |
-| Polyline3D | wire | direct (truck curve topology) | linear-edge truck `Contour`, no bulge/thickness |
+| Polyline | wire | curve-sampled | heavy 3D polyline; sampled from its own curve, bulges kept as arcs |
+| Polyline2D | wire | curve-sampled | 2D polyline with bulge; sampled from its own curve |
+| Polyline3D | wire | curve-sampled | straight edges, no bulge or thickness |
 | RasterImage | wire | direct | boundary rectangle / clipping polygon |
 | Ray | wire | direct | two-point `[base, base + dir×1e6]`, no sampling |
-| Region | mesh | truck-with-direct-fallback | 2D planar ACIS body; same truck path as Solid3D |
+| Region | mesh | kernel-with-direct-fallback | 2D planar ACIS body; same kernel path as Solid3D |
 | Seqend | none | n/a | vertex-sequence terminator sentinel; no output |
 | Shape | wire | direct | small diamond marker at the insertion point |
 | Solid | wire | direct | 2D SOLID: four quad edges as direct `Lines` |
-| Solid3D | mesh | truck-with-direct-fallback | 3DSOLID: parse SAT/SAB → truck `Shell` → `triangulation`; fallback sampler |
-| Spline | wire | direct (truck curve topology) | NURBS/BSpline truck `Edge`, `ParameterDivision1D` sampled |
+| Solid3D | mesh | kernel-with-direct-fallback | 3DSOLID: parse SAT/SAB → lift into a kernel `Body`; fallback sampler |
+| Spline | wire | curve-sampled | NURBS sampled through the kernel's space curve, refined where it bends |
 | Table | both | direct | cell fills (`fill_tris`) + LFF cell text + grid lines |
 | Text | wire | direct | LFF-font stroked glyph polylines |
 | Tolerance | wire | direct | feature-control frame grid + per-cell LFF symbols |

index.html

@@ -39,9 +39,10 @@
       }
       @keyframes ocs-spin { to { transform: rotate(360deg); } }
     </style>
-    <!-- Trunk builds the wasm32 binary without the `solid3d` feature (no 3-D
-         solid kernel / vtkio C deps on the web). See issue #45. -->
-    <link data-trunk rel="rust" data-bin="OpenCADStudio" data-cargo-no-default-features />
+    <!-- Trunk builds the wasm32 binary. The crate has no Cargo features:
+         the geometry kernel is pure Rust, so the web build gets the same
+         solid modelling the native one does. See issue #45. -->
+    <link data-trunk rel="rust" data-bin="OpenCADStudio" />
     <!-- Per-script Noto subsets, fetched lazily at runtime (one alphabet per
          file) so CAD text renders non-Latin scripts on the web. (#141) -->
     <link data-trunk rel="copy-dir" href="web/fonts" />

src/app/update/file.rs

@@ -224,9 +224,8 @@ impl OpenCADStudio {
     /// geometry (EXTRUDE/REVOLVE/SWEEP/LOFT/boolean results) an exact modeler
     /// body derived from its B-rep, so the written DWG/DXF carries real
     /// 3-D geometry other CAD apps can open instead of an empty data stream.
-    /// Curved solids that the exact planar path can't yet express are left
-    /// untouched (handled by the NURBS path).
-    #[cfg(feature = "solid3d")]
+    /// A body holding something the kernel has no ACIS record form for is
+    /// left untouched rather than written out half-complete.
     fn sync_solid_models_to_acis(&mut self, i: usize) {
         use acadrust::EntityType;
         let scene = &mut self.tabs[i].scene;
@@ -256,9 +255,6 @@ impl OpenCADStudio {
         }
     }
 
-    #[cfg(not(feature = "solid3d"))]
-    fn sync_solid_models_to_acis(&mut self, _i: usize) {}
-
     /// Snapshot the persisted UI preferences from live state.
     pub(in crate::app) fn current_settings(&self) -> crate::app::settings::UserSettings {
         crate::app::settings::UserSettings {

src/scene/convert/mod.rs

@@ -1,5 +1,4 @@
 pub mod acad_to_render;
-#[cfg(feature = "solid3d")]
 pub mod acis_export;
 pub mod acis_kernel;
 pub mod dgn_linestyle;