Generalize Triangle into Polygon

crates/fj-kernel/src/operations/build/face.rs

@@ -16,7 +16,7 @@ pub trait BuildFace {
     fn triangle(
         points: [impl Into<Point<3>>; 3],
         objects: &mut Service<Objects>,
-    ) -> Triangle {
+    ) -> Polygon<3> {
         let [a, b, c] = points.map(Into::into);
 
         let surface = Surface::plane_from_points([a, b, c]).insert(objects);
@@ -39,7 +39,7 @@ pub trait BuildFace {
 
         let face = Face::new(surface, exterior, [], None);
 
-        Triangle {
+        Polygon {
             face,
             edges,
             vertices,
@@ -49,16 +49,20 @@ pub trait BuildFace {
 
 impl BuildFace for Face {}
 
-/// A triangle
+/// A polygon
 ///
-/// Returned by [`BuildFace::triangle`].
-pub struct Triangle {
-    /// The face that forms the triangle
+/// # Implementation Note
+///
+/// Currently code that deals with `Polygon` might assume that the polygon has
+/// no holes. Unless you create a `Polygon` yourself, or modify a `Polygon`'s
+/// `face` field to have interior cycles, this should not affect you.
+pub struct Polygon<const D: usize> {
+    /// The face that forms the polygon
     pub face: Face,
 
-    /// The edges of the triangle
-    pub edges: [Handle<HalfEdge>; 3],
+    /// The edges of the polygon
+    pub edges: [Handle<HalfEdge>; D],
 
-    /// The vertices of the triangle
-    pub vertices: [Handle<Vertex>; 3],
+    /// The vertices of the polygon
+    pub vertices: [Handle<Vertex>; D],
 }

crates/fj-kernel/src/operations/build/mod.rs

@@ -7,7 +7,7 @@ mod surface;
 pub use self::{
     cycle::BuildCycle,
     edge::BuildHalfEdge,
-    face::{BuildFace, Triangle},
+    face::{BuildFace, Polygon},
     shell::{BuildShell, Tetrahedron},
     surface::BuildSurface,
 };

crates/fj-kernel/src/operations/build/shell.rs

@@ -7,7 +7,7 @@ use crate::{
     storage::Handle,
 };
 
-use super::{BuildFace, Triangle};
+use super::{BuildFace, Polygon};
 
 /// Build a [`Shell`]
 pub trait BuildShell {
@@ -35,19 +35,19 @@ pub trait BuildShell {
     ) -> Tetrahedron {
         let [a, b, c, d] = points.map(Into::into);
 
-        let [Triangle {
+        let [Polygon {
             face: face_abc,
             edges: [ab, bc, ca],
             vertices: [a, b, c],
-        }, Triangle {
+        }, Polygon {
             face: face_bad,
             edges: [ba, ad, db],
             vertices: [_, _, d],
-        }, Triangle {
+        }, Polygon {
             face: face_dac,
             edges: [da, ac, cd],
             ..
-        }, Triangle {
+        }, Polygon {
             face: face_cbd,
             edges: [cb, bd, dc],
             ..

crates/fj-kernel/src/operations/mod.rs

@@ -7,7 +7,7 @@ mod update;
 pub use self::{
     build::{
         BuildCycle, BuildFace, BuildHalfEdge, BuildShell, BuildSurface,
-        Tetrahedron, Triangle,
+        Polygon, Tetrahedron,
     },
     insert::Insert,
     update::{UpdateCycle, UpdateFace, UpdateHalfEdge, UpdateShell},