test(occara): add test for Shape::mesh()

crates/occara/tests/meshing.rs

@@ -0,0 +1,36 @@
+use occara::{
+    geom::{Direction, Point},
+    shape::Shape,
+};
+
+#[test]
+fn test_mesh_cylinder() {
+    let plane = Point::new(0.0, 0.0, 0.0).plane_axis_with(&Direction::z());
+    let mesh = Shape::cylinder(&plane, 1.0, 1.0).mesh();
+    let vertices = mesh.vertices();
+    let indices = mesh.indices();
+
+    // Check mesh is not empty
+    assert!(vertices.len() > 50, "Too few vertices");
+    assert!(indices.len() > 50, "Too few indices");
+
+    // Check indices are valid
+    assert!(indices.iter().all(|&i| i < vertices.len()), "Invalid index");
+
+    // Check vertices form a cylinder
+    let (min_z, max_z) = vertices
+        .iter()
+        .map(|v| v.z())
+        .fold((f64::INFINITY, f64::NEG_INFINITY), |(min, max), z| {
+            (min.min(z), max.max(z))
+        });
+
+    assert!((max_z - min_z - 1.0).abs() < 1e-6, "Incorrect height");
+
+    let max_radius = vertices
+        .iter()
+        .map(|v| (v.x().powi(2) + v.y().powi(2)).sqrt())
+        .fold(0.0, f64::max);
+
+    assert!((max_radius - 1.0).abs() < 1e-6, "Incorrect radius");
+}