94 lines
2.6 KiB
Rust
94 lines
2.6 KiB
Rust
use super::{Light, SpatialLight};
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use crate::core::LinearColor;
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use crate::{Point, Vector};
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use nalgebra::Unit;
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use serde::Deserialize;
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/// Represent a light emanating from a far away source, with parallel rays on all points.
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#[derive(Debug, PartialEq, Deserialize)]
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pub struct DirectionalLight {
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#[serde(deserialize_with = "crate::serialize::vector_normalizer")]
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direction: Unit<Vector>,
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color: LinearColor,
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}
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impl DirectionalLight {
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/// Creates a new `DirectionalLight`.
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///
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/// # Examples
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///
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/// ```
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/// # use pathtracer::light::DirectionalLight;
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/// # use pathtracer::core::color::LinearColor;
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/// # use pathtracer::Vector;
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/// #
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/// let dir_light = DirectionalLight::new(
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/// Vector::x_axis(),
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/// LinearColor::new(1.0, 0.0, 1.0),
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/// );
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/// ```
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pub fn new(direction: Unit<Vector>, color: LinearColor) -> Self {
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DirectionalLight { direction, color }
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}
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}
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impl Light for DirectionalLight {
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fn illumination(&self, _: &Point) -> LinearColor {
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self.color.clone()
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}
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}
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impl SpatialLight for DirectionalLight {
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fn to_source(&self, _: &Point) -> (Unit<Vector>, f32) {
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(-self.direction, std::f32::INFINITY)
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}
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}
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#[cfg(test)]
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mod test {
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use super::*;
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#[test]
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fn new_works() {
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let direction = Vector::x_axis();
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let color = LinearColor::new(1., 1., 1.);
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let light = DirectionalLight::new(direction, color.clone());
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let res = DirectionalLight { direction, color };
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assert_eq!(light, res)
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}
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fn simple_light() -> impl SpatialLight {
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let direction = Vector::x_axis();
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let color = LinearColor::new(1., 1., 1.);
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DirectionalLight::new(direction, color)
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}
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#[test]
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fn illumination_is_correct() {
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let light = simple_light();
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let lum = light.illumination(&Point::new(1., 1., 1.));
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assert_eq!(lum, LinearColor::new(1., 1., 1.))
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}
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#[test]
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fn to_source_is_correct() {
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let light = simple_light();
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let ans = light.to_source(&Point::new(1., 0., 0.));
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let expected = (
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Unit::new_normalize(Vector::new(-1., 0., 0.)),
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std::f32::INFINITY,
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);
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assert_eq!(ans, expected)
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}
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#[test]
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fn deserialization_works() {
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let yaml = "{direction: [1.0, 0.0, 0.0], color: {r: 1.0, g: 0.5, b: 0.2}}";
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let light: DirectionalLight = serde_yaml::from_str(yaml).unwrap();
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assert_eq!(
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light,
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DirectionalLight::new(Vector::x_axis(), LinearColor::new(1., 0.5, 0.2))
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)
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}
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}
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