RoughnessToAlphaMapping.h

Go to the documentation of this file.

#pragma once
 
#include "Actor/Material/Component/sdl_component_enums.h"
 
#include <Common/primitive_type.h>
 
#include <algorithm>
#include <cmath>
 
namespace ph
{
 
class RoughnessToAlphaMapping final
{
public:
    static real equaled(const real roughness);
 
    static real squared(const real roughness);
 
    static real pbrtV3(const real roughness);
 
    static real map(const real roughness, ERoughnessToAlpha mapType);
};
 
// In-header Implementations:
 
inline real RoughnessToAlphaMapping::equaled(const real roughness)
{
    return roughness;
}
 
inline real RoughnessToAlphaMapping::squared(const real roughness)
{
    return roughness * roughness;
}
 
inline real RoughnessToAlphaMapping::pbrtV3(const real roughness)
{
    const real clampedRoughness = std::max(roughness, 0.001_r);
    const real x                = std::log(clampedRoughness);
 
    return 1.621420000_r + 
           0.819955000_r * x + 
           0.173400000_r * x * x + 
           0.017120100_r * x * x * x + 
           0.000640711_r * x * x * x * x;
}
 
inline real RoughnessToAlphaMapping::map(const real roughness, const ERoughnessToAlpha mapType)
{
    switch(mapType)
    {
    case ERoughnessToAlpha::Equaled:
        return equaled(roughness);
 
    case ERoughnessToAlpha::Squared:
        return squared(roughness);
 
    case ERoughnessToAlpha::PbrtV3:
        return pbrtV3(roughness);
 
    default:
        return squared(roughness);
    }
}
 
}// end namespace ph