/*!
\details
No detailed.
*/
SampledWavelengths WavelengthSampler::sampleRandomly(
Sampler& sampler,
PathState& path_state) noexcept
{
using zisc::cast;
constexpr uint sample_size = SampledWavelengths::size();
constexpr Float inverse_probability = cast<Float>(CoreConfig::spectraSize()) /
cast<Float>(sample_size);
std::array<uint16, sample_size> wavelengths;
for (uint i = 0; i < sample_size; ++i) {
const Float offset = sampler.draw1D(path_state);
path_state.setDimension(path_state.dimension() + 1);
const Float position = cast<Float>(CoreConfig::spectraSize()) * offset;
const uint index = cast<uint>(position);
const uint16 wavelength = getWavelength(index);
wavelengths[i] = wavelength;
}
std::sort(wavelengths.begin(), wavelengths.end());
SampledWavelengths sampled_wavelengths;
for (uint i = 0; i < sample_size; ++i)
sampled_wavelengths.set(i, wavelengths[i], inverse_probability);
sampled_wavelengths.selectPrimaryWavelength(sampler, path_state);
return sampled_wavelengths;
}
/*!
*/
inline
LightSourceInfo UniformLightSourceSampler::sampleInfo(
Sampler& sampler,
const PathState& path_state) const noexcept
{
const auto& light_source_list = lightSourceList();
const Float k = zisc::cast<Float>(light_source_list.size());
const Float r = sampler.draw1D(path_state);
const uint light_number = zisc::cast<uint>(k * r);
return LightSourceInfo{light_source_list[light_number], weightPerLight()};
}
/*!
\details
No detailed.
*/
SampledWavelengths WavelengthSampler::sampleRegularly(
Sampler& sampler,
PathState& path_state) noexcept
{
using zisc::cast;
constexpr uint sample_size = SampledWavelengths::size();
constexpr Float interval = cast<Float>(CoreConfig::spectraSize()) /
cast<Float>(sample_size);
constexpr Float inverse_probability = interval;
SampledWavelengths sampled_wavelengths;
const Float offset = sampler.draw1D(path_state);
for (uint i = 0; i < sample_size; ++i) {
path_state.setDimension(path_state.dimension() + 1);
const uint index = cast<uint>(interval * (cast<Float>(i) + offset));
const uint16 wavelength = getWavelength(index);
sampled_wavelengths.set(i, wavelength, inverse_probability);
}
sampled_wavelengths.selectPrimaryWavelength(sampler, path_state);
return sampled_wavelengths;
}
