use na::{Matrix3, Matrix4, Point2, Point3, Vector2, Vector3}; /// See Example 3.4 of "Graphics and Visualization: Principles & Algorithms" /// by Theoharis, Papaioannou, Platis, Patrikalakis. #[test] fn test_scaling_wrt_point_1() { let a = Point2::new(0.0, 0.0); let b = Point2::new(1.0, 1.0); let c = Point2::new(5.0, 2.0); let scaling = Vector2::new(2.0, 2.0); let scale_about = Matrix3::new_nonuniform_scaling_wrt_point(&scaling, &c); let expected_a = Point2::new(-5.0, -2.0); let expected_b = Point2::new(-3.0, 0.0); let result_a = scale_about.transform_point(&a); let result_b = scale_about.transform_point(&b); let result_c = scale_about.transform_point(&c); assert!(expected_a == result_a); assert!(expected_b == result_b); assert!(c == result_c); } /// Based on the same example as the test above. #[test] fn test_scaling_wrt_point_2() { let a = Point3::new(0.0, 0.0, 1.0); let b = Point3::new(1.0, 1.0, 1.0); let c = Point3::new(5.0, 2.0, 1.0); let scaling = Vector3::new(2.0, 2.0, 1.0); let scale_about = Matrix4::new_nonuniform_scaling_wrt_point(&scaling, &c); let expected_a = Point3::new(-5.0, -2.0, 1.0); let expected_b = Point3::new(-3.0, 0.0, 1.0); let result_a = scale_about.transform_point(&a); let result_b = scale_about.transform_point(&b); let result_c = scale_about.transform_point(&c); assert!(expected_a == result_a); assert!(expected_b == result_b); assert!(c == result_c); } /// Based on https://github.com/emlowry/AiE/blob/50bae4068edb686cf8ffacdf6fab8e7cb22e7eb1/Year%201%20Classwork/MathTest/Matrix4x4TestGroup.cpp#L145 #[test] fn test_scaling_wrt_point_3() { let about = Point3::new(2.0, 1.0, -2.0); let scale = Vector3::new(2.0, 0.5, -1.0); let pt = Point3::new(1.0, 2.0, 3.0); let scale_about = Matrix4::new_nonuniform_scaling_wrt_point(&scale, &about); let expected = Point3::new(0.0, 1.5, -7.0); let result = scale_about.transform_point(&pt); assert!(result == expected); }