Add quad reflection unit test

nicklockwood · Aug 30, 2024 · c004f95 · c004f95
1 parent 0100e5e
commit c004f95
Showing 1 changed file with 24 additions and 0 deletions.
diff --git a/Tests/MeshTests.swift b/Tests/MeshTests.swift
@@ -357,4 +357,28 @@ class MeshTests: XCTestCase {
             XCTAssertFalse(bsp.containsPoint(point))
         }
     }
+
+    // MARK: Reflection
+
+    func testQuadReflectionAlongPlane() {
+
+        let quad = Polygon(unchecked: [
+            Vertex(Vector(-0.5, 1.0, 0.5), .unitY, Vector(0.0, 1.0), .black),
+            Vertex(Vector(0.5, 1.0, 0.5), .unitY, Vector(1.0, 1.0), .black),
+            Vertex(Vector(0.5, 1.0, -0.5), .unitY, Vector(1.0, 0.0), .white),
+            Vertex(Vector(-0.5, 1.0, -0.5), .unitY, Vector(0.0, 0.0), .white),
+        ])
+
+        let expected = Polygon(unchecked: [
+            Vertex(Vector(-0.5, -1.0, -0.5), -.unitY, Vector(0.0, 0.0), .white),
+            Vertex(Vector(0.5, -1.0, -0.5), -.unitY, Vector(1.0, 0.0), .white),
+            Vertex(Vector(0.5, -1.0, 0.5), -.unitY, Vector(1.0, 1.0), .black),
+            Vertex(Vector(-0.5, -1.0, 0.5), -.unitY, Vector(0.0, 1.0), .black),
+        ])
+
+        let reflection = quad.reflect(along: .xz)
+
+        XCTAssertEqual(reflection.plane.normal, -.unitY)
+        XCTAssertEqual(reflection.vertices, expected.vertices)
+    }
 }