1 files changed, 138 insertions, 0 deletions
diff --git a/third_party/rust/plane-split/tests/split.rs b/third_party/rust/plane-split/tests/split.rs
new file mode 100644
index 0000000000..60d1d8035f
--- /dev/null
+++ b/third_party/rust/plane-split/tests/split.rs
@@ -0,0 +1,138 @@
+use euclid::{
+    default::{Rect, Transform3D},
+    rect, vec3, Angle,
+};
+use plane_split::PlaneCut;
+use plane_split::{make_grid, BspSplitter, Polygon};
+use std::f64::consts::FRAC_PI_4;
+
+fn grid_impl(count: usize, splitter: &mut BspSplitter<usize>) {
+    let polys = make_grid(count);
+    let result = splitter.solve(&polys, vec3(0.0, 0.0, 1.0));
+    assert_eq!(result.len(), count + count * count + count * count * count);
+}
+
+#[test]
+fn grid_bsp() {
+    grid_impl(2, &mut BspSplitter::new());
+}
+
+fn sort_rotation(splitter: &mut BspSplitter<usize>) {
+    let transform0: Transform3D<f64> =
+        Transform3D::rotation(0.0, 1.0, 0.0, Angle::radians(-FRAC_PI_4));
+    let transform1: Transform3D<f64> = Transform3D::rotation(0.0, 1.0, 0.0, Angle::radians(0.0));
+    let transform2: Transform3D<f64> =
+        Transform3D::rotation(0.0, 1.0, 0.0, Angle::radians(FRAC_PI_4));
+
+    let rect: Rect<f64> = rect(-10.0, -10.0, 20.0, 20.0);
+    let p1 = Polygon::from_transformed_rect(rect, transform0, 0);
+    let p2 = Polygon::from_transformed_rect(rect, transform1, 1);
+    let p3 = Polygon::from_transformed_rect(rect, transform2, 2);
+    assert!(
+        p1.is_some() && p2.is_some() && p3.is_some(),
+        "Cannot construct transformed polygons"
+    );
+
+    let polys = [p1.unwrap(), p2.unwrap(), p3.unwrap()];
+    let result = splitter.solve(&polys, vec3(0.0, 0.0, -1.0));
+    let ids: Vec<_> = result.iter().map(|poly| poly.anchor).collect();
+    assert_eq!(&ids, &[2, 1, 0, 1, 2]);
+}
+
+#[test]
+fn rotation_bsp() {
+    sort_rotation(&mut BspSplitter::new());
+}
+
+fn sort_trivial(splitter: &mut BspSplitter<usize>) {
+    let anchors: Vec<_> = (0usize..10).collect();
+    let rect: Rect<f64> = rect(-10.0, -10.0, 20.0, 20.0);
+    let polys: Vec<_> = anchors
+        .iter()
+        .map(|&anchor| {
+            let transform: Transform3D<f64> = Transform3D::translation(0.0, 0.0, anchor as f64);
+            let poly = Polygon::from_transformed_rect(rect, transform, anchor);
+            assert!(poly.is_some(), "Cannot construct transformed polygons");
+            poly.unwrap()
+        })
+        .collect();
+
+    let result = splitter.solve(&polys, vec3(0.0, 0.0, -1.0));
+    let anchors1: Vec<_> = result.iter().map(|p| p.anchor).collect();
+    let mut anchors2 = anchors1.clone();
+    anchors2.sort_by_key(|&a| -(a as i32));
+    //make sure Z is sorted backwards
+    assert_eq!(anchors1, anchors2);
+}
+
+fn sort_external(splitter: &mut BspSplitter<usize>) {
+    let rect0: Rect<f64> = rect(-10.0, -10.0, 20.0, 20.0);
+    let poly0 = Polygon::from_rect(rect0, 0);
+    let poly1 = {
+        let transform0: Transform3D<f64> =
+            Transform3D::rotation(1.0, 0.0, 0.0, Angle::radians(2.0 * FRAC_PI_4));
+        let transform1: Transform3D<f64> = Transform3D::translation(0.0, 100.0, 0.0);
+        Polygon::from_transformed_rect(rect0, transform0.then(&transform1), 1).unwrap()
+    };
+
+    let result = splitter.solve(&[poly0, poly1], vec3(1.0, 1.0, 0.0).normalize());
+    let anchors: Vec<_> = result.iter().map(|p| p.anchor).collect();
+    // make sure the second polygon is split in half around the plane of the first one,
+    // even if geometrically their polygons don't intersect.
+    assert_eq!(anchors, vec![1, 0, 1]);
+}
+
+#[test]
+fn trivial_bsp() {
+    sort_trivial(&mut BspSplitter::new());
+}
+
+#[test]
+fn external_bsp() {
+    sort_external(&mut BspSplitter::new());
+}
+
+#[test]
+fn test_cut() {
+    use smallvec::SmallVec;
+    let rect: Rect<f64> = rect(-10.0, -10.0, 20.0, 20.0);
+    let poly = Polygon::from_rect(rect, 0);
+    let mut poly2 = Polygon::from_rect(rect, 0);
+    // test robustness for positions
+    for p in &mut poly2.points {
+        p.z += 0.00000001;
+    }
+
+    let mut front: SmallVec<[Polygon<i32>; 2]> = SmallVec::new();
+    let mut back: SmallVec<[Polygon<i32>; 2]> = SmallVec::new();
+
+    assert_eq!(poly.cut(&poly2, &mut front, &mut back), PlaneCut::Sibling);
+    assert!(front.is_empty());
+    assert!(back.is_empty());
+
+    // test robustness for normal
+    poly2.plane.normal.z += 0.00000001;
+    assert_eq!(poly.cut(&poly2, &mut front, &mut back), PlaneCut::Sibling);
+    assert!(front.is_empty());
+    assert!(back.is_empty());
+
+    // test opposite normal handling
+    poly2.plane.normal *= -1.0;
+    assert_eq!(poly.cut(&poly2, &mut front, &mut back), PlaneCut::Sibling);
+    assert!(front.is_empty());
+    assert!(back.is_empty());
+
+    // test grouping front
+    poly2.plane.offset += 0.1;
+    assert_eq!(poly.cut(&poly2, &mut front, &mut back), PlaneCut::Cut);
+    assert_eq!(front.len(), 1);
+    assert!(back.is_empty());
+
+    front.clear();
+
+    // test grouping back
+    poly2.plane.normal *= -1.0;
+    assert_eq!(poly.cut(&poly2, &mut front, &mut back), PlaneCut::Cut);
+    assert_eq!(back.len(), 1);
+    assert!(front.is_empty());
+}