pbrt/shared/src/lights/goniometric.rs

90 lines
2.5 KiB
Rust

use crate::core::geometry::{Bounds3f, Normal3f, Point2f, Point2i, Point3f, Ray, Vector3f};
use crate::core::image::Image;
use crate::core::light::{
LightBase, LightBounds, LightLiSample, LightSampleContext, LightTrait, LightType,
};
use crate::core::medium::MediumInterface;
use crate::core::spectrum::{Spectrum, SpectrumTrait};
use crate::spectra::{DenselySampledSpectrum, SampledSpectrum, SampledWavelengths};
use crate::utils::math::equal_area_sphere_to_square;
use crate::utils::sampling::PiecewiseConstant2D;
use crate::utils::{Ptr, Transform};
use crate::{Float, PI};
#[derive(Debug, Clone, Copy)]
pub struct GoniometricLight {
pub base: LightBase,
pub iemit: Ptr<DenselySampledSpectrum>,
pub scale: Float,
pub image: Ptr<Image>,
pub distrib: Ptr<PiecewiseConstant2D>,
}
impl GoniometricLight {
pub fn i(&self, w: Vector3f, lambda: &SampledWavelengths) -> SampledSpectrum {
let uv = equal_area_sphere_to_square(w);
self.scale * self.iemit.sample(lambda) * self.image.lookup_nearest_channel(uv, 0)
}
}
impl LightTrait for GoniometricLight {
fn base(&self) -> &LightBase {
&self.base
}
fn sample_li(
&self,
_ctx: &LightSampleContext,
_u: Point2f,
_lambda: &SampledWavelengths,
_allow_incomplete_pdf: bool,
) -> Option<LightLiSample> {
todo!()
}
fn pdf_li(
&self,
_ctx: &LightSampleContext,
_wi: Vector3f,
_allow_incomplete_pdf: bool,
) -> Float {
0.
}
fn l(
&self,
_p: Point3f,
_n: Normal3f,
_uv: Point2f,
_w: Vector3f,
_lambda: &SampledWavelengths,
) -> SampledSpectrum {
todo!()
}
fn le(&self, _ray: &Ray, _lambda: &SampledWavelengths) -> SampledSpectrum {
todo!()
}
#[cfg(not(target_os = "cuda"))]
fn preprocess(&mut self, _scene_bounds: &Bounds3f) {
todo!()
}
#[cfg(not(target_os = "cuda"))]
fn bounds(&self) -> Option<LightBounds> {
todo!()
}
#[cfg(not(target_os = "cuda"))]
fn phi(&self, lambda: SampledWavelengths) -> SampledSpectrum {
let resolution = self.image.resolution();
let mut sum_y = 0.;
for y in 0..resolution.y() {
for x in 0..resolution.x() {
sum_y += self.image.get_channel(Point2i::new(x, y), 0);
}
}
self.scale * self.iemit.sample(&lambda) * 4. * PI * sum_y
/ (resolution.x() * resolution.y()) as Float
}
}