From 6d3e738b6524975a317dafebb7bb4a0bd9716c62 Mon Sep 17 00:00:00 2001
From: Hanno Braun <hanno@braun-odw.eu>
Date: Sat, 9 Apr 2022 11:56:50 +0200
Subject: [PATCH] Don't use `CycleApprox` in `Polygon`

`Polygon` doesn't know of or care about approximations. It cares about
its polygonal chain. So this change makes sense from a conceptual
perspective.

It also makes sense from a practical perspective, as this enables some
simplifications of `Polygon`, which should further improve its
testability.
---
 fj-kernel/src/algorithms/triangulation/mod.rs     |  9 +++++++--
 fj-kernel/src/algorithms/triangulation/polygon.rs | 10 +++++-----
 2 files changed, 12 insertions(+), 7 deletions(-)

diff --git a/fj-kernel/src/algorithms/triangulation/mod.rs b/fj-kernel/src/algorithms/triangulation/mod.rs
index d8ae78144..bacb48f01 100644
--- a/fj-kernel/src/algorithms/triangulation/mod.rs
+++ b/fj-kernel/src/algorithms/triangulation/mod.rs
@@ -35,8 +35,13 @@ pub fn triangulate(
                     })
                     .collect();
                 let face_as_polygon = Polygon::new(surface)
-                    .with_exterior(approx.exterior)
-                    .with_interiors(approx.interiors);
+                    .with_exterior(approx.exterior.points)
+                    .with_interiors(
+                        approx
+                            .interiors
+                            .into_iter()
+                            .map(|interior| interior.points),
+                    );
 
                 let mut triangles = delaunay(points);
                 triangles.retain(|triangle| {
diff --git a/fj-kernel/src/algorithms/triangulation/polygon.rs b/fj-kernel/src/algorithms/triangulation/polygon.rs
index dabad39b3..c86ed3f15 100644
--- a/fj-kernel/src/algorithms/triangulation/polygon.rs
+++ b/fj-kernel/src/algorithms/triangulation/polygon.rs
@@ -1,11 +1,11 @@
 use std::collections::BTreeSet;
 
 use fj_debug::{DebugInfo, TriangleEdgeCheck};
-use fj_math::{Point, Scalar, Segment};
+use fj_math::{Point, PolyChain, Scalar, Segment};
 use parry2d_f64::query::{Ray as Ray2, RayCast as _};
 use parry3d_f64::query::Ray as Ray3;
 
-use crate::{algorithms::CycleApprox, geometry::Surface};
+use crate::geometry::Surface;
 
 pub struct Polygon {
     surface: Surface,
@@ -22,13 +22,13 @@ impl Polygon {
         }
     }
 
-    pub fn with_exterior(self, exterior: impl Into<CycleApprox>) -> Self {
+    pub fn with_exterior(self, exterior: impl Into<PolyChain<3>>) -> Self {
         self.with_approx(exterior)
     }
 
     pub fn with_interiors(
         mut self,
-        interiors: impl IntoIterator<Item = impl Into<CycleApprox>>,
+        interiors: impl IntoIterator<Item = impl Into<PolyChain<3>>>,
     ) -> Self {
         for interior in interiors {
             self = self.with_approx(interior);
@@ -37,7 +37,7 @@ impl Polygon {
         self
     }
 
-    fn with_approx(mut self, approx: impl Into<CycleApprox>) -> Self {
+    fn with_approx(mut self, approx: impl Into<PolyChain<3>>) -> Self {
         for segment in approx.into().segments() {
             let segment = segment.points().map(|point| {
                 // Can't panic, unless the approximation wrongfully generates