1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99

//! Reflect a distance field about an arbitrary axis.

use rust_gpu_bridge::prelude::{Vec2, Vec3};
use type_fields::Field;

use crate::prelude::{Distance, Operator, SignedDistanceField, SignedDistanceOperator};

/// Reflect a distance field about an arbitrary axis.
#[derive(Debug, Copy, Clone, PartialEq, Field)]
pub struct ReflectOp<Dim> {
    pub axis: Dim,
}

impl Default for ReflectOp<f32> {
    fn default() -> Self {
        ReflectOp { axis: 1.0 }
    }
}

impl Default for ReflectOp<Vec2> {
    fn default() -> Self {
        ReflectOp { axis: Vec2::X }
    }
}

impl Default for ReflectOp<Vec3> {
    fn default() -> Self {
        ReflectOp { axis: Vec3::X }
    }
}

impl SignedDistanceOperator<f32, Distance> for ReflectOp<f32> {
    fn operator<Sdf>(&self, sdf: &Sdf, p: f32) -> Distance
    where
        Sdf: SignedDistanceField<f32, Distance>,
    {
        assert!(self.axis.abs() == 1.0, "ReflectOp axis must be normalized");

        let q = p - 2.0 * (p * self.axis).min(0.0) * self.axis;

        sdf.evaluate(q)
    }
}

impl SignedDistanceOperator<Vec2, Distance> for ReflectOp<Vec2> {
    fn operator<Sdf>(&self, sdf: &Sdf, p: Vec2) -> Distance
    where
        Sdf: SignedDistanceField<Vec2, Distance>,
    {
        assert!(
            self.axis.is_normalized(),
            "ReflectOp axis must be normalized"
        );

        let q = p - 2.0 * p.dot(self.axis).min(0.0) * self.axis;

        sdf.evaluate(q)
    }
}

impl SignedDistanceOperator<Vec3, Distance> for ReflectOp<Vec3> {
    fn operator<Sdf>(&self, sdf: &Sdf, p: Vec3) -> Distance
    where
        Sdf: SignedDistanceField<Vec3, Distance>,
    {
        assert!(
            self.axis.is_normalized(),
            "ReflectOp axis must be normalized"
        );

        let q = p - 2.0 * p.dot(self.axis).min(0.0) * self.axis;

        sdf.evaluate(q)
    }
}

/// Reflect a distance field about an arbitrary axis.
pub type Reflect<Dim, Sdf> = Operator<ReflectOp<Dim>, Sdf>;

impl<Dim, Sdf> Reflect<Dim, Sdf> {
    pub fn axis(&mut self) -> &mut Dim {
        &mut self.op.axis
    }
}

#[cfg(test)]
pub mod test {
    use rust_gpu_bridge::prelude::Vec3;
    use type_fields::field::Field;

    use crate::signed_distance_field::shapes::composite::Sphere;

    use super::Reflect;

    #[test]
    fn test_reflect() {
        Reflect::<_, Sphere>::default().with(Reflect::axis, Vec3::default());
    }
}