M0: workspace, geometry foundation, sketch constraint solver, kernel boundary

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

crates/kernel/src/body.rs

@@ -0,0 +1,232 @@
+use monstertruck_meshing::prelude::*;
+use monstertruck_modeling as mt;
+use serde::Serialize;
+use solvecraft_geom::{Mesh, Vec3};
+
+use crate::{KernelError, Result, guard};
+
+pub(crate) type Solid = mt::Solid;
+
+/// A solid body (one or more closed shells). Cheap to clone; never mutated in place.
+#[derive(Clone, Debug)]
+pub struct Body {
+    pub(crate) solid: std::sync::Arc<Solid>,
+}
+
+/// A B-rep edge as seen by the rest of the application.
+#[derive(Clone, Debug, Serialize)]
+pub struct EdgeInfo {
+    pub index: usize,
+    /// Polyline approximation.
+    pub points: Vec<Vec3>,
+    /// Point halfway along the polyline (used to re-find the edge).
+    pub mid: Vec3,
+    pub length: f64,
+}
+
+/// A B-rep face.
+#[derive(Clone, Debug, Serialize)]
+pub struct FaceInfo {
+    pub index: usize,
+    pub area: f64,
+    pub centroid: Vec3,
+    /// Unit normal if the face is planar.
+    pub plane_normal: Option<Vec3>,
+}
+
+pub(crate) fn p3(v: Vec3) -> mt::Point3 {
+    mt::Point3::new(v.x, v.y, v.z)
+}
+pub(crate) fn v3(v: Vec3) -> mt::Vector3 {
+    mt::Vector3::new(v.x, v.y, v.z)
+}
+pub(crate) fn from_p3(p: mt::Point3) -> Vec3 {
+    Vec3::new(p.x, p.y, p.z)
+}
+
+fn polyline_mid(pts: &[Vec3]) -> (Vec3, f64) {
+    let len: f64 = pts.windows(2).map(|w| w.first().zip(w.get(1)).map(|(a, b)| a.dist(*b)).unwrap_or(0.0)).sum();
+    let mut acc = 0.0;
+    for w in pts.windows(2) {
+        if let (Some(a), Some(b)) = (w.first(), w.get(1)) {
+            let l = a.dist(*b);
+            if acc + l >= len * 0.5 && l > 0.0 {
+                return (a.lerp(*b, (len * 0.5 - acc) / l), len);
+            }
+            acc += l;
+        }
+    }
+    (pts.first().copied().unwrap_or_default(), len)
+}
+
+impl Body {
+    pub(crate) fn new(mut solid: Solid) -> Result<Body> {
+        if solid.is_empty() {
+            return Err(KernelError::Failed("empty result".into()));
+        }
+        // Orient outward: a closed solid must have positive volume.
+        let v = guard("orient", || Ok(solid.triangulation(1.0).to_polygon().volume()))?;
+        if v < 0.0 {
+            solid.not();
+        }
+        Ok(Body { solid: std::sync::Arc::new(solid) })
+    }
+
+    /// A deep copy of the solid that can be mutated without affecting other bodies.
+    pub(crate) fn deep_copy(&self) -> Solid {
+        mt::builder::clone(&*self.solid)
+    }
+
+    /// Characteristic size (bounding box diagonal) for tolerances.
+    pub fn size(&self) -> f64 {
+        let mut b = solvecraft_geom::Aabb3::EMPTY;
+        for v in self.solid.vertex_iter() {
+            b.add(from_p3(v.point()));
+        }
+        let d = b.diagonal();
+        if d.is_finite() && d > 0.0 { d } else { 1.0 }
+    }
+
+    /// Distinct edges in a stable order (the order of `edges()` and `tessellate().edges`).
+    pub(crate) fn unique_edges(solid: &Solid) -> Vec<mt::Edge> {
+        let mut seen = std::collections::HashSet::new();
+        solid.edge_iter().filter(|e| seen.insert(e.id())).collect()
+    }
+
+    /// Triangulate with chord tolerance `tol` (mm). Triangles carry their face index.
+    pub fn tessellate(&self, tol: f64) -> Result<Mesh> {
+        let tol = if tol.is_finite() && tol > 0.0 { tol } else { 0.05 };
+        let tol = tol.max(self.size() * 1e-6);
+        guard("tessellate", || {
+            let meshed = self.solid.triangulation(tol);
+            let mut out = Mesh::default();
+            for (fi, face) in meshed.face_iter().enumerate() {
+                let Some(pm) = face.surface() else { continue };
+                let flip = !face.orientation();
+                let base = u32::try_from(out.positions.len()).unwrap_or(u32::MAX);
+                let pos = pm.positions();
+                let nor = pm.normals();
+                // Expand to per-corner vertices so normals stay per face (crisp edges).
+                for tri in pm.faces().triangle_iter() {
+                    let mut idx = [0u32; 3];
+                    for (k, v) in tri.iter().enumerate() {
+                        let Some(p) = pos.get(v.pos) else { continue };
+                        let n = v.nor.and_then(|ni| nor.get(ni)).map(|n| Vec3::new(n.x, n.y, n.z)).unwrap_or(Vec3::Z);
+                        let n = if flip { -n } else { n };
+                        out.positions.push(Vec3::new(p.x, p.y, p.z));
+                        out.normals.push(n);
+                        if let Some(slot) = idx.get_mut(k) {
+                            *slot = u32::try_from(out.positions.len() - 1).unwrap_or(0);
+                        }
+                    }
+                    let t = if flip { [idx[0], idx[2], idx[1]] } else { idx };
+                    out.triangles.push(t);
+                    out.tri_face.push(u32::try_from(fi).unwrap_or(u32::MAX));
+                }
+                let _ = base;
+            }
+            // Fill missing normals from geometry.
+            for t in &out.triangles {
+                let (Some(a), Some(b), Some(c)) =
+                    (out.positions.get(t[0] as usize), out.positions.get(t[1] as usize), out.positions.get(t[2] as usize))
+                else {
+                    continue;
+                };
+                let fnrm = (b - a).cross(c - a).normalized().unwrap_or(Vec3::Z);
+                for k in t {
+                    if let Some(n) = out.normals.get_mut(*k as usize)
+                        && (n.dot(fnrm) < -0.2 || n.len() < 0.5)
+                    {
+                        *n = fnrm;
+                    }
+                }
+            }
+            let mut seen = std::collections::HashSet::new();
+            for e in meshed.edge_iter() {
+                if !seen.insert(e.id()) {
+                    continue;
+                }
+                let c = e.oriented_curve();
+                out.edges.push(c.0.iter().map(|p| Vec3::new(p.x, p.y, p.z)).collect());
+            }
+            Ok(out)
+        })
+    }
+
+    /// Edges with polylines (index = position in [`Body::tessellate`]'s `edges`).
+    pub fn edges(&self, tol: f64) -> Result<Vec<EdgeInfo>> {
+        let m = self.tessellate(tol)?;
+        Ok(m.edges
+            .into_iter()
+            .enumerate()
+            .map(|(index, points)| {
+                let (mid, length) = polyline_mid(&points);
+                EdgeInfo { index, points, mid, length }
+            })
+            .collect())
+    }
+
+    /// Faces with area and centroid.
+    pub fn faces(&self, tol: f64) -> Result<Vec<FaceInfo>> {
+        let m = self.tessellate(tol)?;
+        let nf = self.solid.face_iter().count();
+        let mut acc: Vec<(f64, Vec3, Vec3, bool)> = vec![(0.0, Vec3::ZERO, Vec3::ZERO, true); nf];
+        for (t, f) in m.triangles.iter().zip(&m.tri_face) {
+            let Some([a, b, c]) = m.tri(t) else { continue };
+            let cr = (b - a).cross(c - a);
+            let ar = cr.len() * 0.5;
+            if let Some(slot) = acc.get_mut(*f as usize) {
+                slot.0 += ar;
+                slot.1 += (a + b + c) * (ar / 3.0);
+                if let Some(n) = cr.normalized() {
+                    if slot.2 == Vec3::ZERO {
+                        slot.2 = n;
+                    } else if slot.2.dot(n) < 1.0 - 1e-6 {
+                        slot.3 = false;
+                    }
+                }
+            }
+        }
+        Ok(acc
+            .into_iter()
+            .enumerate()
+            .map(|(index, (area, c, n, planar))| FaceInfo {
+                index,
+                area,
+                centroid: if area > 0.0 { c / area } else { Vec3::ZERO },
+                plane_normal: (planar && n != Vec3::ZERO).then_some(n),
+            })
+            .collect())
+    }
+
+    /// Index of the edge closest to `p` (by polyline distance).
+    pub fn nearest_edge(&self, p: Vec3, tol: f64) -> Result<Option<(usize, f64)>> {
+        let edges = self.edges(tol)?;
+        let mut best: Option<(usize, f64)> = None;
+        for e in &edges {
+            for w in e.points.windows(2) {
+                if let (Some(a), Some(b)) = (w.first(), w.get(1)) {
+                    let d = p.dist_to_segment(*a, *b);
+                    if best.is_none_or(|(_, bd)| d < bd) {
+                        best = Some((e.index, d));
+                    }
+                }
+            }
+        }
+        Ok(best)
+    }
+
+    pub fn face_count(&self) -> usize {
+        self.solid.face_iter().count()
+    }
+    pub fn edge_count(&self) -> usize {
+        Self::unique_edges(&self.solid).len()
+    }
+    pub fn vertex_count(&self) -> usize {
+        let mut seen = std::collections::HashSet::new();
+        self.solid.vertex_iter().filter(|v| seen.insert(v.id())).count()
+    }
+    pub fn shell_count(&self) -> usize {
+        self.solid.boundaries().len()
+    }
+}