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