Merge pull request #905 from hannobraun/intersection

Clean up intersection code

crates/fj-kernel/src/algorithms/intersection/curve_edge.rs

@@ -1,10 +1,10 @@
 use fj_math::{Point, Segment};
 
-use crate::objects::{CurveKind, Edge};
+use crate::objects::{Curve, CurveKind, Edge};
 
 use super::LineSegmentIntersection;
 
-/// The intersection between a curve and an [`Edge`], in curve coordinates
+/// The intersection between a [`Curve`] and an [`Edge`], in curve coordinates
 #[derive(Clone, Copy, Debug, Eq, PartialEq, Hash, Ord, PartialOrd)]
 pub enum CurveEdgeIntersection {
     /// The curve and edge intersect at a point
@@ -26,10 +26,10 @@ impl CurveEdgeIntersection {
     /// # Panics
     ///
     /// Currently, only intersections between lines and line segments can be
-    /// computed. Panics, if a different type of curve or [`Edge`] is
+    /// computed. Panics, if a different type of [`Curve`] or [`Edge`] is
     /// passed.
-    pub fn compute(curve: &CurveKind<2>, edge: &Edge) -> Option<Self> {
-        let curve_as_line = match curve {
+    pub fn compute(curve: &Curve, edge: &Edge) -> Option<Self> {
+        let curve_as_line = match curve.kind() {
             CurveKind::Line(line) => line,
             _ => todo!("Curve-edge intersection only supports lines"),
         };
@@ -87,7 +87,7 @@ mod tests {
         let edge = Edge::build()
             .line_segment_from_points(&surface, [[1., -1.], [1., 1.]]);
 
-        let intersection = CurveEdgeIntersection::compute(curve.kind(), &edge);
+        let intersection = CurveEdgeIntersection::compute(&curve, &edge);
 
         assert_eq!(
             intersection,
@@ -104,7 +104,7 @@ mod tests {
         let edge = Edge::build()
             .line_segment_from_points(&surface, [[-1., -1.], [-1., 1.]]);
 
-        let intersection = CurveEdgeIntersection::compute(curve.kind(), &edge);
+        let intersection = CurveEdgeIntersection::compute(&curve, &edge);
 
         assert_eq!(
             intersection,
@@ -121,7 +121,7 @@ mod tests {
         let edge = Edge::build()
             .line_segment_from_points(&surface, [[-1., -1.], [1., -1.]]);
 
-        let intersection = CurveEdgeIntersection::compute(curve.kind(), &edge);
+        let intersection = CurveEdgeIntersection::compute(&curve, &edge);
 
         assert!(intersection.is_none());
     }
@@ -133,7 +133,7 @@ mod tests {
         let edge = Edge::build()
             .line_segment_from_points(&surface, [[-1., 0.], [1., 0.]]);
 
-        let intersection = CurveEdgeIntersection::compute(curve.kind(), &edge);
+        let intersection = CurveEdgeIntersection::compute(&curve, &edge);
 
         assert_eq!(
             intersection,

crates/fj-kernel/src/algorithms/intersection/curve_face.rs

@@ -4,10 +4,10 @@ use fj_math::Point;
 
 use crate::{
     algorithms::intersection::CurveEdgeIntersection,
-    objects::{CurveKind, Face},
+    objects::{Curve, Face},
 };
 
-/// The intersections between a curve and a [`Face`], in curve coordinates
+/// The intersections between a [`Curve`] and a [`Face`], in curve coordinates
 #[derive(Clone, Debug, Eq, PartialEq, Hash, Ord, PartialOrd)]
 pub struct CurveFaceIntersectionList {
     intervals: Vec<CurveFaceIntersection>,
@@ -27,8 +27,8 @@ impl CurveFaceIntersectionList {
         Self { intervals }
     }
 
-    /// Compute the intersections between a curve and a [`Face`]
-    pub fn compute(curve: &CurveKind<2>, face: &Face) -> Self {
+    /// Compute the intersections between a [`Curve`] and a [`Face`]
+    pub fn compute(curve: &Curve, face: &Face) -> Self {
         let edges = face.all_cycles().flat_map(|cycle| {
             let edges: Vec<_> = cycle.edges().cloned().collect();
             edges
@@ -140,18 +140,16 @@ pub type CurveFaceIntersection = [Point<1>; 2];
 
 #[cfg(test)]
 mod tests {
-    use fj_math::{Line, Point, Vector};
-
-    use crate::objects::{CurveKind, Face, Surface};
+    use crate::objects::{Curve, Face, Surface};
 
     use super::CurveFaceIntersectionList;
 
     #[test]
     fn compute() {
-        let curve = CurveKind::Line(Line {
-            origin: Point::from([-3., 0.]),
-            direction: Vector::from([1., 0.]),
-        });
+        let surface = Surface::xy_plane();
+
+        let curve =
+            Curve::build(surface).line_from_points([[-3., 0.], [-2., 0.]]);
 
         #[rustfmt::skip]
         let exterior = [
@@ -168,7 +166,6 @@ mod tests {
             [-1.,  1.],
         ];
 
-        let surface = Surface::xy_plane();
         let face = Face::build(surface)
             .polygon_from_points(exterior)
             .with_hole(interior);

crates/fj-kernel/src/algorithms/intersection/surface_surface.rs

@@ -1,31 +1,27 @@
 use fj_math::{Line, Point, Scalar, Vector};
 
-use crate::objects::{CurveKind, Surface};
+use crate::objects::{Curve, CurveKind, GlobalCurve, Surface};
 
 /// The intersection between two surfaces
 #[derive(Clone, Debug, Eq, PartialEq, Hash, Ord, PartialOrd)]
 pub struct SurfaceSurfaceIntersection {
-    /// The intersection curves, in the coordinates of the input surfaces
-    pub local_intersection_curves: [CurveKind<2>; 2],
-
-    /// The intersection curve, in global coordinates
-    pub global_intersection_curve: CurveKind<3>,
+    /// The intersection curves
+    pub intersection_curves: [Curve; 2],
 }
 
 impl SurfaceSurfaceIntersection {
     /// Compute the intersection between two surfaces
-    pub fn compute(a: &Surface, b: &Surface) -> Option<Self> {
+    pub fn compute(surfaces: [&Surface; 2]) -> Option<Self> {
         // Algorithm from Real-Time Collision Detection by Christer Ericson. See
         // section 5.4.4, Intersection of Two Planes.
         //
         // Adaptations were made to get the intersection curves in local
         // coordinates for each surface.
 
-        let a_parametric = PlaneParametric::extract_from_surface(a);
-        let b_parametric = PlaneParametric::extract_from_surface(b);
-
-        let a = PlaneConstantNormal::from_parametric_plane(&a_parametric);
-        let b = PlaneConstantNormal::from_parametric_plane(&b_parametric);
+        let planes_parametric =
+            surfaces.map(PlaneParametric::extract_from_surface);
+        let [a, b] = planes_parametric
+            .map(|plane| PlaneConstantNormal::from_parametric_plane(&plane));
 
         let direction = a.normal.cross(&b.normal);
 
@@ -48,18 +44,21 @@ impl SurfaceSurfaceIntersection {
 
         let line = Line { origin, direction };
 
-        let curve_a = project_line_into_plane(&line, &a_parametric);
-        let curve_b = project_line_into_plane(&line, &b_parametric);
-        let curve_global = CurveKind::Line(Line { origin, direction });
+        let curves = planes_parametric.map(|plane| {
+            let local = project_line_into_plane(&line, &plane);
+            let global = CurveKind::Line(Line { origin, direction });
+
+            Curve::new(local, GlobalCurve::from_kind(global))
+        });
 
         Some(Self {
-            local_intersection_curves: [curve_a, curve_b],
-            global_intersection_curve: curve_global,
+            intersection_curves: curves,
         })
     }
 }
 
 /// A plane in parametric form
+#[derive(Clone, Copy)]
 struct PlaneParametric {
     pub origin: Point<3>,
     pub u: Vector<3>,
@@ -154,26 +153,22 @@ mod tests {
         let xz = Surface::xz_plane();
 
         // Coincident and parallel planes don't have an intersection curve.
-        assert_eq!(SurfaceSurfaceIntersection::compute(&xy, &xy), None);
+        assert_eq!(SurfaceSurfaceIntersection::compute([&xy, &xy]), None);
         assert_eq!(
-            SurfaceSurfaceIntersection::compute(
+            SurfaceSurfaceIntersection::compute([
                 &xy,
                 &xy.transform(&Transform::translation([0., 0., 1.]))
-            ),
+            ]),
             None,
         );
 
         let expected_xy = Curve::build(xy).u_axis();
         let expected_xz = Curve::build(xz).u_axis();
 
         assert_eq!(
-            SurfaceSurfaceIntersection::compute(&xy, &xz),
+            SurfaceSurfaceIntersection::compute([&xy, &xz]),
             Some(SurfaceSurfaceIntersection {
-                local_intersection_curves: [
-                    *expected_xy.kind(),
-                    *expected_xz.kind()
-                ],
-                global_intersection_curve: *expected_xy.global().kind(),
+                intersection_curves: [expected_xy, expected_xz],
             })
         );
     }