material-param.h

#ifndef PBRLAB_MATERIAL_PARAM_H_
#define PBRLAB_MATERIAL_PARAM_H_

#include <stdint.h>

#include "type.h"

#ifdef __clang__
#pragma clang diagnostic push
#pragma clang diagnostic ignored "-Weverything"
#endif

#include "mpark/variant.hpp"

#ifdef __clang__
#pragma clang diagnostic pop
#endif

namespace pbrlab {
enum MaterialParameterType {
  kCyclesPrincipledBsdfParameter = 0,
  kHairBsdfParameter
};
struct CyclesPrincipledBsdfParameter {
  float3 base_color        = {static_cast<float>(0.8), static_cast<float>(0.8),
                       static_cast<float>(0.8)};
  float subsurface         = static_cast<float>(0.0);
  float3 subsurface_radius = {static_cast<float>(1.0), static_cast<float>(1.0),
                              static_cast<float>(1.0)};
  float3 subsurface_color  = {static_cast<float>(0.7), static_cast<float>(0.1),
                             static_cast<float>(0.1)};
  float metallic           = static_cast<float>(0.0);
  float specular           = static_cast<float>(0.5);
  float specular_tint      = static_cast<float>(0.0);
  float roughness          = static_cast<float>(0.5);
  float anisotropic        = static_cast<float>(0.0);
  float anisotropic_rotation       = static_cast<float>(0.0);
  float sheen                      = static_cast<float>(0.0);
  float sheen_tint                 = static_cast<float>(0.5);
  float clearcoat                  = static_cast<float>(0.0);
  float clearcoat_roughness        = static_cast<float>(0.03);
  float ior                        = static_cast<float>(1.45);
  float transmission               = static_cast<float>(0.0);
  float transmission_roughness     = static_cast<float>(0.0);
  uint32_t base_color_tex_id       = static_cast<uint32_t>(-1);
  uint32_t subsurface_color_tex_id = static_cast<uint32_t>(-1);

  std::string name = "";
};

struct HairBsdfParameter {
  enum ColoringHair { kRGB = 0, kMelanin };
  ColoringHair coloring_hair = kMelanin;
  float3 base_color          = {0.18f, 0.06f, 0.02f};

  float melanin           = 0.5f;
  float melanin_redness   = 0.8f;
  float melanin_randomize = 0.f;

  float roughness           = 0.2f;
  float azimuthal_roughness = 0.3f;

  float ior = 1.55f;

  float shift = 2.f;

  float3 specular_tint        = {1.f, 1.f, 1.f};
  float3 second_specular_tint = {1.f, 1.f, 1.f};
  float3 transmission_tint    = {1.f, 1.f, 1.f};

  std::string name = "";
};

using MaterialParameter =
    mpark::variant<CyclesPrincipledBsdfParameter, HairBsdfParameter>;

inline void SetMaterialName(const std::string& name,
                            MaterialParameter* material_param) {
  if (material_param->index() == kCyclesPrincipledBsdfParameter) {
    mpark::get<kCyclesPrincipledBsdfParameter>(*material_param).name = name;
  } else if (material_param->index() == kHairBsdfParameter) {
    mpark::get<kHairBsdfParameter>(*material_param).name = name;
  } else {
    assert(false);
  }
}

inline std::string GetMaterialName(const MaterialParameter& material_param) {
  if (material_param.index() == kCyclesPrincipledBsdfParameter) {
    return mpark::get<kCyclesPrincipledBsdfParameter>(material_param).name;
  } else if (material_param.index() == kHairBsdfParameter) {
    return mpark::get<kHairBsdfParameter>(material_param).name;
  } else {
    assert(false);
  }
  return "";
}
}  // namespace pbrlab
#endif  // PBRLAB_MAfloatERIAL_PARAM_H_