1 files changed, 147 insertions, 0 deletions
diff --git a/third_party/rust/plane-split/tests/clip.rs b/third_party/rust/plane-split/tests/clip.rs
new file mode 100644
index 0000000000..f243c3e843
--- /dev/null
+++ b/third_party/rust/plane-split/tests/clip.rs
@@ -0,0 +1,147 @@
+use euclid::{
+    default::{Rect, Transform3D},
+    point3, rect, vec3, Angle,
+};
+use plane_split::{Clipper, Plane, Polygon};
+
+use std::f64::consts::FRAC_PI_4;
+
+#[test]
+fn clip_in() {
+    let plane = Plane::from_unnormalized(vec3(1.0, 0.0, 1.0), 20.0)
+        .unwrap()
+        .unwrap();
+    let mut clipper = Clipper::new();
+    clipper.add(plane);
+
+    let poly = Polygon::from_points(
+        [
+            point3(-10.0, -10.0, 0.0),
+            point3(10.0, -10.0, 0.0),
+            point3(10.0, 10.0, 0.0),
+            point3(-10.0, 10.0, 0.0),
+        ],
+        0,
+    )
+    .unwrap();
+
+    let results = clipper.clip(poly.clone());
+    assert_eq!(results[0], poly);
+    assert_eq!(results.len(), 1);
+}
+
+#[test]
+fn clip_out() {
+    let plane = Plane::from_unnormalized(vec3(1.0, 0.0, 1.0), -20.0)
+        .unwrap()
+        .unwrap();
+    let mut clipper = Clipper::new();
+    clipper.add(plane);
+
+    let poly = Polygon::from_points(
+        [
+            point3(-10.0, -10.0, 0.0),
+            point3(10.0, -10.0, 0.0),
+            point3(10.0, 10.0, 0.0),
+            point3(-10.0, 10.0, 0.0),
+        ],
+        0,
+    )
+    .unwrap();
+
+    let results = clipper.clip(poly);
+    assert!(results.is_empty());
+}
+
+#[test]
+fn clip_parallel() {
+    let plane = Plane {
+        normal: vec3(0.0, 0.0, 1.0),
+        offset: 0.0,
+    };
+    let mut clipper = Clipper::new();
+    clipper.add(plane);
+
+    let poly = Polygon::from_points(
+        [
+            point3(-10.0, -10.0, 0.0),
+            point3(10.0, -10.0, 0.0),
+            point3(10.0, 10.0, 0.0),
+            point3(-10.0, 10.0, 0.0),
+        ],
+        0,
+    )
+    .unwrap();
+
+    let results = clipper.clip(poly);
+    assert!(results.is_empty());
+}
+
+#[test]
+fn clip_repeat() {
+    let plane = Plane::from_unnormalized(vec3(1.0, 0.0, 1.0), 0.0)
+        .unwrap()
+        .unwrap();
+    let mut clipper = Clipper::new();
+    clipper.add(plane.clone());
+    clipper.add(plane.clone());
+
+    let poly = Polygon::from_points(
+        [
+            point3(-10.0, -10.0, 0.0),
+            point3(10.0, -10.0, 0.0),
+            point3(10.0, 10.0, 0.0),
+            point3(-10.0, 10.0, 0.0),
+        ],
+        0,
+    )
+    .unwrap();
+
+    let results = clipper.clip(poly);
+    assert_eq!(results.len(), 1);
+    assert!(plane.signed_distance_sum_to(&results[0]) > 0.0);
+}
+
+#[test]
+fn clip_transformed() {
+    let t_rot: Transform3D<f64> = Transform3D::rotation(0.0, 1.0, 0.0, Angle::radians(-FRAC_PI_4));
+    let t_div: Transform3D<f64> = Transform3D::perspective(5.0);
+    let transform = t_rot.then(&t_div);
+
+    let polygon = Polygon::from_rect(rect(-10.0, -10.0, 20.0, 20.0), 0);
+    let bounds: Rect<f64> = rect(-1.0, -1.0, 2.0, 2.0);
+
+    let mut clipper = Clipper::new();
+    let results = clipper.clip_transformed(polygon, &transform, Some(bounds));
+    // iterating enforces the transformation checks/unwraps
+    assert_ne!(0, results.unwrap().count());
+}
+
+#[test]
+fn clip_badly_transformed() {
+    let mut tx = Transform3D::<f64>::identity();
+    tx.m14 = -0.0000001;
+    tx.m44 = 0.0;
+
+    let mut clipper = Clipper::new();
+    let polygon = Polygon::from_rect(rect(-10.0, -10.0, 20.0, 20.0), 0);
+    let results = clipper.clip_transformed(polygon, &tx, None);
+    assert!(results.is_err());
+}
+
+#[test]
+fn clip_near_coplanar() {
+    let tx = Transform3D::<f64>::new(
+        1.0, 0.0, 0.0, 0.0, 0.0, 1.0, 0.0, 0.0, -960.0, -625.0, 1.0, -1.0, 100.0, -2852.0, 0.0, 1.0,
+    );
+    let mut clipper = Clipper::new();
+    let polygon = Polygon::from_rect(rect(0.0, 0.0, 1703.0, 4020.0), 0);
+
+    let bounds1 = rect(0.0, -430.0, 2048.0, 2048.0);
+    let results1 = clipper.clip_transformed(polygon.clone(), &tx, Some(bounds1));
+    assert_ne!(0, results1.unwrap().count());
+
+    let bounds2 = rect(0.0, 0.0, 816.0, 1039.0);
+    let results2 = clipper.clip_transformed(polygon, &tx, Some(bounds2));
+    assert_ne!(0, results2.unwrap().count());
+}