vanrijn/src/materials.rs

67 lines
2.0 KiB
Rust

use nalgebra::{RealField, Vector3};
use super::colour::{ColourRgbF, NamedColour};
use std::fmt::Debug;
pub trait Material<T: RealField>: Debug {
fn bsdf<'a>(
&'a self,
) -> Box<dyn Fn(Vector3<T>, Vector3<T>, ColourRgbF<T>) -> ColourRgbF<T> + 'a>;
}
#[derive(Debug)]
pub struct LambertianMaterial<T: RealField> {
pub colour: ColourRgbF<T>,
pub diffuse_strength: T,
}
impl<T: RealField> LambertianMaterial<T> {
pub fn new_dummy() -> LambertianMaterial<T> {
LambertianMaterial {
colour: ColourRgbF::new(T::one(), T::one(), T::one()),
diffuse_strength: T::one(),
}
}
}
impl<T: RealField> Material<T> for LambertianMaterial<T> {
fn bsdf<'a>(
&'a self,
) -> Box<dyn Fn(Vector3<T>, Vector3<T>, ColourRgbF<T>) -> ColourRgbF<T> + 'a> {
Box::new(
move |_w_o: Vector3<T>, _w_i: Vector3<T>, colour_in: ColourRgbF<T>| {
self.colour * colour_in * self.diffuse_strength
},
)
}
}
#[derive(Debug)]
pub struct PhongMaterial<T: RealField> {
pub colour: ColourRgbF<T>,
pub diffuse_strength: T,
pub specular_strength: T,
pub smoothness: T,
}
impl<T: RealField> Material<T> for PhongMaterial<T> {
fn bsdf<'a>(
&'a self,
) -> Box<dyn Fn(Vector3<T>, Vector3<T>, ColourRgbF<T>) -> ColourRgbF<T> + 'a> {
Box::new(
move |w_o: Vector3<T>, w_i: Vector3<T>, colour_in: ColourRgbF<T>| {
if w_i.z < T::zero() || w_o.z < T::zero() {
ColourRgbF::from_vector3(&Vector3::zeros())
} else {
let reflection_vector = Vector3::new(-w_i.x, -w_i.y, w_i.z);
self.colour * colour_in * self.diffuse_strength
+ ColourRgbF::from_named(NamedColour::White)
* w_o.dot(&reflection_vector).abs().powf(self.smoothness)
* (self.specular_strength / w_i.dot(&Vector3::z_axis()))
}
},
)
}
}