ray-tracer-challenge/ray-tracer
1
0
Fork 0
Code Issues Pull Requests Projects Releases Wiki Activity

added scaling

Browse Source
This commit is contained in:
Jon Janzen
2021-09-03 19:42:49 -06:00
parent 48b5d0a400
commit e523852cd4
1 changed files with 42 additions and 3 deletions
Download Patch File Download Diff File Expand all files Collapse all files

45
features/src/transformations.rs
View File

@@ -5,9 +5,18 @@ use crate::structs::Tuple;
impl Matrix {
pub fn translation(x: f32, y: f32, z: f32) -> Self {
Matrix::from_array([
[1.0, 0.0, 0.0, x],
[0.0, 1.0, 0.0, y],
[0.0, 0.0, 1.0, z],
[1.0, 0.0, 0.0, x ],
[0.0, 1.0, 0.0, y ],
[0.0, 0.0, 1.0, z ],
[0.0, 0.0, 0.0, 1.0],
])
}
pub fn scaling(x: f32, y: f32, z: f32) -> Self {
Matrix::from_array([
[ x, 0.0, 0.0, 0.0],
[0.0, y, 0.0, 0.0],
[0.0, 0.0, z, 0.0],
[0.0, 0.0, 0.0, 1.0],
])
}
@@ -47,4 +56,34 @@ mod tests {
assert_eq!(&transform * &v, v);
}
#[test]
fn scaling_matrix_applied_to_point() {
let transform = Matrix::scaling(2.0, 3.0, 4.0);
let p = Tuple::point(-4.0, 6.0, 8.0);
let expected = Tuple::point(-8.0, 18.0, 32.0);
assert_eq!(&transform * &p, expected);
}
#[test]
fn scaling_matrix_apled_to_vector() {
let transform = Matrix::scaling(2.0, 3.0, 4.0);
let v = Tuple::vector(-4.0, 6.0, 8.0);
assert_eq!(&transform * &v, Tuple::vector(-8.0, 18.0, 32.0));
}
#[test]
fn multiplying_inverse_of_scaling_matrix() {
let transform = Matrix::scaling(2.0, 3.0, 4.0);
let inv = transform.inverse();
let v = Tuple::vector(-4.0, 6.0, 8.0);
assert_eq!(&inv * &v, Tuple::vector(-2.0, 2.0, 2.0));
}
#[test]
fn reflection_is_scaling_by_a_negative_value() {
let transform = Matrix::scaling(-1.0, 1.0, 1.0);
let p = Tuple::point(2.0, 3.0, 4.0);
assert_eq!(&transform * &p, Tuple::point(-2.0, 3.0, 4.0));
}
}