solidcraft-smlib: Brep::stitch and Brep::offset_sheet, and the fork pinned at e3d478d

The safe wrappers of the fork's smlib_stitch (a body's faces sewn at a tolerance,
oriented, with whether it closed) and smlib_offset_sheet (a sheet's faces onto
their offsets), for the kernel's Stitch and Offset Surface.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_017itGh5fpMEousnZ91cYcVt

crates/smlib/SMLIB_REV

@@ -1 +1 @@
-2152a2cbbb12ee2c0990caf3e85621f7552d5198
+4a81dd9ca9a7bbd41c5125e4cc7b026f6abae5e5

crates/smlib/src/ffi.rs

@@ -192,6 +192,7 @@ pub mod history;
 pub mod measure;
 pub mod ops;
 pub mod split;
+pub mod sheets;
 pub mod ssi;
 pub mod sweeps;
 pub mod trim;

crates/smlib/src/ffi/sheets.rs

@@ -0,0 +1,40 @@
+//! The sheets block of `capi/include/smlib.h` (`smlib_stitch`, `smlib_offset_sheet`; the fork's
+//! `capi/src/smlib_sheets.cpp`), declared by hand. Part of the FFI boundary, like its parent:
+//! called only through [`crate::sheets`].
+
+#![allow(unsafe_code)]
+
+use super::Handle;
+#[cfg(not(feature = "native"))]
+use super::NOT_BUILT;
+#[cfg(feature = "native")]
+use super::{RawBrep, new_brep};
+
+#[cfg(feature = "native")]
+unsafe extern "C" {
+    fn smlib_stitch(brep: *const RawBrep, tolerance: f64, out_closed: *mut i32, out: *mut *mut RawBrep) -> i32;
+    fn smlib_offset_sheet(sheet: *const RawBrep, distance: f64, out: *mut *mut RawBrep) -> i32;
+}
+
+/// The stitched body and whether it closed into a solid.
+#[cfg(feature = "native")]
+pub fn stitch(b: &Handle, tolerance: f64) -> Result<(Handle, bool), i32> {
+    let mut closed = 0i32;
+    let h = new_brep(|out| unsafe { smlib_stitch(b.raw(), tolerance, &mut closed, out) })?;
+    Ok((h, closed != 0))
+}
+
+#[cfg(feature = "native")]
+pub fn offset_sheet(b: &Handle, distance: f64) -> Result<Handle, i32> {
+    new_brep(|out| unsafe { smlib_offset_sheet(b.raw(), distance, out) })
+}
+
+#[cfg(not(feature = "native"))]
+pub fn stitch(_: &Handle, _: f64) -> Result<(Handle, bool), i32> {
+    Err(NOT_BUILT)
+}
+
+#[cfg(not(feature = "native"))]
+pub fn offset_sheet(_: &Handle, _: f64) -> Result<Handle, i32> {
+    Err(NOT_BUILT)
+}

crates/smlib/src/lib.rs

@@ -24,6 +24,7 @@ pub mod import;
 mod measure;
 mod ops;
 mod split;
+mod sheets;
 pub mod ssi;
 pub mod sweeps;
 pub mod trim;

crates/smlib/src/sheets.rs

@@ -0,0 +1,23 @@
+//! SMLib's sheet operations: sewing a body's faces along the edges that coincide, and a sheet's
+//! offset along its faces' normals. Each returns a new body and leaves its input unchanged;
+//! tagged inputs ([`Brep::tagged`]) give results whose [`Brep::history`] says where each face and
+//! edge came from.
+
+use crate::{Brep, Result, error, ffi, init};
+
+impl Brep {
+    /// The faces sewn along the vertices and edges that coincide within `tolerance` mm, oriented
+    /// outward where they close into a solid, else only made to agree across their shared edges;
+    /// with whether the result is a closed solid.
+    pub fn stitch(&self, tolerance: f64) -> Result<(Brep, bool)> {
+        init()?;
+        ffi::sheets::stitch(&self.0, tolerance).map(|(h, closed)| (Brep(h), closed)).map_err(error)
+    }
+
+    /// This sheet with every face moved onto its surface's offset by `distance` along its normal
+    /// (negative: against it). A closed solid is [`crate::Error::Argument`].
+    pub fn offset_sheet(&self, distance: f64) -> Result<Brep> {
+        init()?;
+        ffi::sheets::offset_sheet(&self.0, distance).map(Brep).map_err(error)
+    }
+}