Factor integrators into submodules

src/integrators/mod.rs

@@ -0,0 +1,19 @@
+use super::colour::Photon;
+use super::raycasting::IntersectionInfo;
+use super::sampler::Sampler;
+
+mod whitted_integrator;
+pub use whitted_integrator::*;
+
+mod simple_random_integrator;
+pub use simple_random_integrator::*;
+
+pub trait Integrator {
+    fn integrate(
+        &self,
+        sampler: &Sampler,
+        info: &IntersectionInfo,
+        photon: &Photon,
+        recursion_limit: u16,
+    ) -> Photon;
+}

src/integrators/simple_random_integrator.rs

@@ -0,0 +1,65 @@
+use crate::math::Vec3;
+use crate::colour::{ColourRgbF, Photon, Spectrum};
+use crate::materials::MaterialSampleResult;
+use crate::raycasting::{IntersectionInfo, Ray};
+use crate::sampler::Sampler;
+use crate::util::algebra_utils::try_change_of_basis_matrix;
+
+use super::Integrator;
+
+pub struct SimpleRandomIntegrator {}
+
+impl Integrator for SimpleRandomIntegrator {
+    fn integrate(
+        &self,
+        sampler: &Sampler,
+        info: &IntersectionInfo,
+        photon: &Photon,
+        recursion_limit: u16,
+    ) -> Photon {
+        if recursion_limit == 0 {
+            return Photon {
+                wavelength: 0.0,
+                intensity: 0.0,
+            };
+        }
+        let world_to_bsdf_space =
+            try_change_of_basis_matrix(&info.tangent, &info.cotangent, &info.normal)
+                .expect("Normal, tangent and cotangent don't form a valid basis.");
+        let bsdf_to_world_space = world_to_bsdf_space
+            .try_inverse()
+            .expect("Expected matrix to be invertable.");
+        let world_space_w_i = info.retro;
+        let w_i = world_to_bsdf_space * world_space_w_i;
+        let MaterialSampleResult {
+            direction: w_o,
+            pdf: w_o_pdf,
+        } = info.material.sample(&w_i, &photon);
+        let world_space_w_o = bsdf_to_world_space * w_o;
+        info.material.bsdf()(
+            &w_o,
+            &w_i,
+            &match sampler.sample(&Ray::new(info.location, world_space_w_o).bias(0.000_000_1)) {
+                None => photon.set_intensity(test_lighting_environment(
+                    &world_space_w_o,
+                    photon.wavelength,
+                )),
+                Some(recursive_hit) => {
+                    self.integrate(&sampler, &recursive_hit, &photon, recursion_limit - 1)
+                }
+            }
+            .scale_intensity(w_o_pdf)
+            .scale_intensity(world_space_w_o.dot(&info.normal).abs()),
+        )
+    }
+}
+
+pub fn test_lighting_environment(w_o: &Vec3, wavelength: f64) -> f64 {
+    let sun_direction = Vec3::new(1.0, 1.0, -1.0).normalize();
+    if w_o.dot(&sun_direction) >= 0.99 {
+        300.0
+    } else {
+        let sky_colour = ColourRgbF::new(w_o.y(), w_o.y(), 1.0);
+        Spectrum::reflection_from_linear_rgb(&sky_colour).intensity_at_wavelength(wavelength)
+    }
+}

src/integrators/whitted_integrator.rs

@@ -1,20 +1,11 @@
 use crate::math::Vec3;
+use crate::colour::{Photon, Spectrum};
+use crate::materials::MaterialSampleResult;
+use crate::raycasting::{IntersectionInfo, Ray};
+use crate::sampler::Sampler;
+use crate::util::algebra_utils::try_change_of_basis_matrix;
 
-use super::colour::{ColourRgbF, Photon, Spectrum};
+use super::Integrator;
-use super::materials::MaterialSampleResult;
-use super::raycasting::{IntersectionInfo, Ray};
-use super::sampler::Sampler;
-use super::util::algebra_utils::try_change_of_basis_matrix;
-
-pub trait Integrator {
-    fn integrate(
-        &self,
-        sampler: &Sampler,
-        info: &IntersectionInfo,
-        photon: &Photon,
-        recursion_limit: u16,
-    ) -> Photon;
-}
 
 pub struct DirectionalLight {
     pub direction: Vec3,
@@ -94,60 +85,3 @@ impl Integrator for WhittedIntegrator {
             })
     }
 }
-
-pub struct SimpleRandomIntegrator {}
-
-impl Integrator for SimpleRandomIntegrator {
-    fn integrate(
-        &self,
-        sampler: &Sampler,
-        info: &IntersectionInfo,
-        photon: &Photon,
-        recursion_limit: u16,
-    ) -> Photon {
-        if recursion_limit == 0 {
-            return Photon {
-                wavelength: 0.0,
-                intensity: 0.0,
-            };
-        }
-        let world_to_bsdf_space =
-            try_change_of_basis_matrix(&info.tangent, &info.cotangent, &info.normal)
-                .expect("Normal, tangent and cotangent don't form a valid basis.");
-        let bsdf_to_world_space = world_to_bsdf_space
-            .try_inverse()
-            .expect("Expected matrix to be invertable.");
-        let world_space_w_i = info.retro;
-        let w_i = world_to_bsdf_space * world_space_w_i;
-        let MaterialSampleResult {
-            direction: w_o,
-            pdf: w_o_pdf,
-        } = info.material.sample(&w_i, &photon);
-        let world_space_w_o = bsdf_to_world_space * w_o;
-        info.material.bsdf()(
-            &w_o,
-            &w_i,
-            &match sampler.sample(&Ray::new(info.location, world_space_w_o).bias(0.000_000_1)) {
-                None => photon.set_intensity(test_lighting_environment(
-                    &world_space_w_o,
-                    photon.wavelength,
-                )),
-                Some(recursive_hit) => {
-                    self.integrate(&sampler, &recursive_hit, &photon, recursion_limit - 1)
-                }
-            }
-            .scale_intensity(w_o_pdf)
-            .scale_intensity(world_space_w_o.dot(&info.normal).abs()),
-        )
-    }
-}
-
-pub fn test_lighting_environment(w_o: &Vec3, wavelength: f64) -> f64 {
-    let sun_direction = Vec3::new(1.0, 1.0, -1.0).normalize();
-    if w_o.dot(&sun_direction) >= 0.99 {
-        300.0
-    } else {
-        let sky_colour = ColourRgbF::new(w_o.y(), w_o.y(), 1.0);
-        Spectrum::reflection_from_linear_rgb(&sky_colour).intensity_at_wavelength(wavelength)
-    }
-}