Simplify debug info

This is less useful than what we had before, but I'm about to make
changes to the algorithm, and this is what the new algorithm will be
able to support easily. We can add more useful info again, as required.

fj-app/src/graphics/vertices.rs

@@ -112,21 +112,13 @@ impl From<&DebugInfo> for Vertices {
                 green
             };
 
-            self_.push_line(
-                [
-                    triangle_edge_check.ray.origin,
-                    triangle_edge_check.ray.origin
-                        + triangle_edge_check.ray.dir,
-                ],
-                normal,
-                color,
-            );
+            self_.push_cross(triangle_edge_check.origin.to_na(), normal, color);
 
             for &hit in &triangle_edge_check.hits {
-                let point = triangle_edge_check.ray.point_at(hit);
+                let line = hit.points().map(|point| point.to_na());
                 let color = [0., 0., 0., 1.];
 
-                self_.push_cross(point, normal, color);
+                self_.push_line(line, normal, color);
             }
         }
 

fj-debug/src/lib.rs

@@ -7,7 +7,7 @@
 
 #![deny(missing_docs)]
 
-use parry3d_f64::query::Ray;
+use fj_math::{Point, Segment};
 
 /// Debug info from the CAD kernel that can be visualized
 ///
@@ -36,18 +36,18 @@ impl DebugInfo {
 
 /// Record of a check to determine if a triangle edge is within a face
 pub struct TriangleEdgeCheck {
-    /// The ray used to perform the check
-    pub ray: Ray,
+    /// The origin of the ray used to perform the check
+    pub origin: Point<3>,
 
-    /// Where the ray hit any edges of the face
-    pub hits: Vec<f64>,
+    /// The points where the ray hit edges of the face
+    pub hits: Vec<Segment<3>>,
 }
 
 impl TriangleEdgeCheck {
     /// Construct a new instance
-    pub fn new(ray: Ray) -> Self {
+    pub fn new(origin: Point<3>) -> Self {
         Self {
-            ray,
+            origin,
             hits: Vec::new(),
         }
     }

fj-kernel/src/algorithms/triangulation/polygon.rs

@@ -3,7 +3,6 @@ use std::collections::BTreeSet;
 use fj_debug::{DebugInfo, TriangleEdgeCheck};
 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::geometry::Surface;
 
@@ -102,10 +101,8 @@ impl Polygon {
             dir: dir.to_na(),
         };
 
-        let mut check = TriangleEdgeCheck::new(Ray3 {
-            origin: self.surface.point_surface_to_model(&point).to_na(),
-            dir: self.surface.vector_surface_to_model(&dir).to_na(),
-        });
+        let mut check =
+            TriangleEdgeCheck::new(self.surface.point_surface_to_model(&point));
 
         // We need to keep track of where our ray hits the edges. Otherwise, if
         // the ray hits a vertex, we might count that hit twice, as every vertex
@@ -130,7 +127,11 @@ impl Polygon {
                 let t = (t * eps).round() / eps;
 
                 if hits.insert(t) {
-                    check.hits.push(t.into_f64());
+                    let edge =
+                        Segment::from_points(edge.points().map(|point| {
+                            self.surface.point_surface_to_model(&point)
+                        }));
+                    check.hits.push(edge);
                 }
             }
         }