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
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138

//! Careful abstraction of geometric shapes in a ray tracer is a key
//! component of a clean system design, and shapes are the ideal
//! candidate for an object-oriented approach. All geometric
//! primitives implement a common interface, and the rest of the
//! renderer can use this interface without needing any details about
//! the underlying shape. This makes it possible to separate the
//! geometric and the shading subsystem of pbrt.

// pbrt
use crate::core::geometry::{Bounds3f, Point2f, Ray, Vector3f};
use crate::core::interaction::{Interaction, InteractionCommon, SurfaceInteraction};
use crate::core::pbrt::Float;
use crate::core::transform::Transform;
use crate::shapes::curve::Curve;
use crate::shapes::cylinder::Cylinder;
use crate::shapes::disk::Disk;
use crate::shapes::sphere::Sphere;
use crate::shapes::triangle::Triangle;

// see shape.h

pub enum Shape {
    Crv(Curve),
    Clndr(Cylinder),
    Dsk(Disk),
    Sphr(Sphere),
    Trngl(Triangle),
}

impl Shape {
    pub fn object_bound(&self) -> Bounds3f {
        match self {
            Shape::Crv(shape) => shape.object_bound(),
            Shape::Clndr(shape) => shape.object_bound(),
            Shape::Dsk(shape) => shape.object_bound(),
            Shape::Sphr(shape) => shape.object_bound(),
            Shape::Trngl(shape) => shape.object_bound(),
        }
    }
    pub fn world_bound(&self) -> Bounds3f {
        match self {
            Shape::Crv(shape) => shape.world_bound(),
            Shape::Clndr(shape) => shape.world_bound(),
            Shape::Dsk(shape) => shape.world_bound(),
            Shape::Sphr(shape) => shape.world_bound(),
            Shape::Trngl(shape) => shape.world_bound(),
        }
    }
    pub fn intersect(&self, r: &Ray, t_hit: &mut Float, isect: &mut SurfaceInteraction) -> bool {
        match self {
            Shape::Crv(shape) => shape.intersect(r, t_hit, isect),
            Shape::Clndr(shape) => shape.intersect(r, t_hit, isect),
            Shape::Dsk(shape) => shape.intersect(r, t_hit, isect),
            Shape::Sphr(shape) => shape.intersect(r, t_hit, isect),
            Shape::Trngl(shape) => shape.intersect(r, t_hit, isect),
        }
    }
    pub fn intersect_p(&self, r: &Ray) -> bool {
        match self {
            Shape::Crv(shape) => shape.intersect_p(r),
            Shape::Clndr(shape) => shape.intersect_p(r),
            Shape::Dsk(shape) => shape.intersect_p(r),
            Shape::Sphr(shape) => shape.intersect_p(r),
            Shape::Trngl(shape) => shape.intersect_p(r),
        }
    }
    pub fn get_reverse_orientation(&self) -> bool {
        match self {
            Shape::Crv(shape) => shape.get_reverse_orientation(),
            Shape::Clndr(shape) => shape.get_reverse_orientation(),
            Shape::Dsk(shape) => shape.get_reverse_orientation(),
            Shape::Sphr(shape) => shape.get_reverse_orientation(),
            Shape::Trngl(shape) => shape.get_reverse_orientation(),
        }
    }
    pub fn get_transform_swaps_handedness(&self) -> bool {
        match self {
            Shape::Crv(shape) => shape.get_transform_swaps_handedness(),
            Shape::Clndr(shape) => shape.get_transform_swaps_handedness(),
            Shape::Dsk(shape) => shape.get_transform_swaps_handedness(),
            Shape::Sphr(shape) => shape.get_transform_swaps_handedness(),
            Shape::Trngl(shape) => shape.get_transform_swaps_handedness(),
        }
    }
    pub fn get_object_to_world(&self) -> Transform {
        match self {
            Shape::Crv(shape) => shape.get_object_to_world(),
            Shape::Clndr(shape) => shape.get_object_to_world(),
            Shape::Dsk(shape) => shape.get_object_to_world(),
            Shape::Sphr(shape) => shape.get_object_to_world(),
            Shape::Trngl(shape) => shape.get_object_to_world(),
        }
    }
    pub fn area(&self) -> Float {
        match self {
            Shape::Crv(shape) => shape.area(),
            Shape::Clndr(shape) => shape.area(),
            Shape::Dsk(shape) => shape.area(),
            Shape::Sphr(shape) => shape.area(),
            Shape::Trngl(shape) => shape.area(),
        }
    }
    pub fn sample(&self, u: Point2f, pdf: &mut Float) -> InteractionCommon {
        match self {
            Shape::Crv(shape) => shape.sample(u, pdf),
            Shape::Clndr(shape) => shape.sample(u, pdf),
            Shape::Dsk(shape) => shape.sample(u, pdf),
            Shape::Sphr(shape) => shape.sample(u, pdf),
            Shape::Trngl(shape) => shape.sample(u, pdf),
        }
    }
    pub fn pdf(&self, _iref: &InteractionCommon) -> Float {
        1.0 as Float / self.area()
    }
    pub fn sample_with_ref_point(
        &self,
        iref: &InteractionCommon,
        u: Point2f,
        pdf: &mut Float,
    ) -> InteractionCommon {
        match self {
            Shape::Crv(shape) => shape.sample_with_ref_point(iref, u, pdf),
            Shape::Clndr(shape) => shape.sample_with_ref_point(iref, u, pdf),
            Shape::Dsk(shape) => shape.sample_with_ref_point(iref, u, pdf),
            Shape::Sphr(shape) => shape.sample_with_ref_point(iref, u, pdf),
            Shape::Trngl(shape) => shape.sample_with_ref_point(iref, u, pdf),
        }
    }
    pub fn pdf_with_ref_point(&self, iref: &dyn Interaction, wi: &Vector3f) -> Float {
        match self {
            Shape::Crv(shape) => shape.pdf_with_ref_point(iref, wi),
            Shape::Clndr(shape) => shape.pdf_with_ref_point(iref, wi),
            Shape::Dsk(shape) => shape.pdf_with_ref_point(iref, wi),
            Shape::Sphr(shape) => shape.pdf_with_ref_point(iref, wi),
            Shape::Trngl(shape) => shape.pdf_with_ref_point(iref, wi),
        }
    }
}