28 lines
1.0 KiB
Rust
28 lines
1.0 KiB
Rust
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extern crate alga;
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extern crate nalgebra as na;
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use alga::linear::Transformation;
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use na::{Vector3, Vector4, Point3, Matrix4};
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fn main() {
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let mut m = Matrix4::new_rotation_wrt_point(Vector3::x() * 1.57, Point3::new(1.0, 2.0, 1.0));
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m.append_scaling_mut(2.0);
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let point1 = Point3::new(2.0, 3.0, 4.0);
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let homogeneous_point2 = Vector4::new(2.0, 3.0, 4.0, 1.0);
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// First option: use the dedicated `.transform_point(...)` method.
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let transformed_point1 = m.transform_point(&point1);
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// Second option: use the homogeneous coordinates of the point.
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let transformed_homogeneous_point2 = m * homogeneous_point2;
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// Recover the 3D point from its 4D homogeneous coordinates.
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let transformed_point2 = Point3::from_homogeneous(transformed_homogeneous_point2);
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// Check that transforming the 3D point with the `.transform_point` method is
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// indeed equivalent to multiplying its 4D homogeneous coordinates by the 4x4
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// matrix.
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assert_eq!(transformed_point1, transformed_point2.unwrap());
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}
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